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Archive for the ‘Gene Therapy & Gene Editing Development’ Category


Embryogenesis in Mechanical Womb

Reporter and Curator: Dr. Sudipta Saha, Ph.D.

A highly effective platforms for the ex utero culture of post-implantation mouse embryos have been developed in the present study by scientists of the Weizmann Institute of Science in Israel. The study was published in the journal Nature. They have grown more than 1,000 embryos in this way. This study enables the appropriate development of embryos from before gastrulation (embryonic day (E) 5.5) until the hindlimb formation stage (E11). Late gastrulating embryos (E7.5) are grown in three-dimensional rotating bottles, whereas extended culture from pre-gastrulation stages (E5.5 or E6.5) requires a combination of static and rotating bottle culture platforms.

At Day 11 of development more than halfway through a mouse pregnancy the researchers compared them to those developing in the uteruses of living mice and were found to be identical. Histological, molecular and single-cell RNA sequencing analyses confirm that the ex utero cultured embryos recapitulate in utero development precisely. The mouse embryos looked perfectly normal. All their organs developed as expected, along with their limbs and circulatory and nervous systems. Their tiny hearts were beating at a normal 170 beats per minute. But, the lab-grown embryos becomes too large to survive without a blood supply. They had a placenta and a yolk sack, but the nutrient solution that fed them through diffusion was no longer sufficient. So, a suitable mechanism for blood supply is required to be developed.

Till date the only way to study the development of tissues and organs is to turn to species like worms, frogs and flies that do not need a uterus, or to remove embryos from the uteruses of experimental animals at varying times, providing glimpses of development more like in snapshots than in live videos. This research will help scientists understand how mammals develop and how gene mutations, nutrients and environmental conditions may affect the fetus. This will allow researchers to mechanistically interrogate post-implantation morphogenesis and artificial embryogenesis in mammals. In the future it may be possible to develop a human embryo from fertilization to birth entirely outside the uterus. But the work may one day raise profound questions about whether other animals, even humans, should or could be cultured outside a living womb.

References:

https://www.nature.com/articles/s41586-021-03416-3

https://www.sciencedirect.com/science/article/pii/S0092867414000750?via%3Dihub

https://onlinelibrary.wiley.com/doi/abs/10.1111/j.1469-185X.1978.tb00993.x

https://www.nature.com/articles/199297a0

https://rep.bioscientifica.com/view/journals/rep/35/1/jrf_35_1_018.xml

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Top Industrialization Challenges of Gene Therapy Manufacturing

Guest Authors:

Dr. Mark Szczypka

Global Director, Process Development Services

Pall Corporation

https://www.pall.com/

and

Clive Glover

Director, Cell & Gene Therapy

Pall Corporation

https://www.pall.com/

What Is Gene Therapy? How Does It Save and Improve the Quality of Life?

What Is Gene Therapy?

Gene therapy is a new and exciting technique, defined as the use of genetic material to cure or alleviate disease. It is considered revolutionary, yet still in its infancy, with many new therapies currently undergoing clinical trials. 

Gene therapy has the potential to transform the treatment for diseases, significantly changing how doctors manage and treat patients. 

Two Types of Gene Therapy

There are two main types of gene therapy. 

The first corrects a specific disease causing genetic mutation. These are targeted towards inherited genetic disorders such as hemophilia or Duchenne muscular dystrophy. The second gives new functions to cells allowing them to fight disease.

A good example of these therapies are chimeric antigen receptor T cell (CAR-T) therapies. Both Novartis’ Kymriah and Gilead’s Yescarta are examples of CAR-T therapies, that have demonstrated exceptional cancer remission rates where other forms of treatment have failed.

Cancer is the by far the largest category of disease with 65% of gene therapy clinical trials being investigated, followed by 11.1% for inherited monogenetic disease, 7% for infectious disease, and 6.9% for cardiovascular disease1.

How Does Genetic Material Get Delivered to Host Cell(s)?

Genetic material gets delivered to a host cell via a delivery system known as a vector. Vectors deliver genetic material via one of the two methods. By directly injecting genetic material into the patient (in vivo), and where selected cells collected from the patient, undergo modification outside (ex vivo) before introducing them back into the patient.

The most commonly used type of vector is a virus. While there are other methods of delivering genetic material into a cell, viruses have now been developed that demonstrate a good balance between efficacy and safety. 

 

Commercially Successful Gene Therapies

Developing a commercially successful gene therapy is challenging. It requires balancing several different considerations. Having a clinical effective therapy is essential, but this alone is not sufficient to ensure product success. In addition to this, reimbursement, quality and regulatory considerations, and manufacturing also must be considered. 

To date, a total 11 gene therapies have received marketing approval. However, behind this there is a strong clinical pipeline with >1000 clinical trials underway, and 92 drugs in Phase 32.

Furthermore, there has been significant investment with >$50B being invested in the area in the past 3 years3.

This investment, coupled with the accelerating understanding of disease at the genetic level, holds immense potential. Academic, commercial manufacturers, and industry suppliers are actively seeking new approaches that deliver these therapies as quick as possible to a waiting population.

Author Details:

Clive Glover

Director, Cell & Gene Therapy

Pall Corporation

https://www.pall.com/

Top Industrialization Challenges of Gene Therapy Manufacturing

Manufacturing and scale-up of industrialized processes to manufacture gene therapy products are accompanied by many challenges that must be overcome to succeed in the marketplace. Commercialization of gene therapies for patient use is time consuming and requires substantial financial investment and dedicated resources.

Despite the unique range of challenges associated with gene therapy development, the quest to bring these therapies to market is worthwhile because the therapeutic potential of the treatments is revolutionary and the commercial opportunity is considerable. The process to industrialization is complex, but the benefits of successful development of robust processes are huge. The industry is rapidly expanding and is implementing novel approaches to overcome existing challenges, using innovative methods for medicinal application and developing new drugs to treat rare diseases.

Manufacturing sufficient quantities of high quality product, is an area that requires substantial developmental effort. Challenges surrounding reimbursement for treatment, and the pressures associated with shorter time to approval, both increase burden placed on manufactures to rapidly develop suitable processes that are cost-effective. Cost of goods (COGs) need to be kept below critical threshold levels to drive sufficient profit margins, even though process development timelines are aggressive and short. There are a multitude of critical decisions and considerations to overcome. 

This blog explores some of these fundamental manufacturing challenges in more detail.

Scalable Manufacturing Platform

Technologies used to manufacture gene therapy biologics are advancing at very rapid pace. Not having a platform that is suitable nor scalable is a significant challenge many manufacturers face. It is a necessity throughout clinical development stages to be able to optimize the manufacturing process. However, any change in the manufacturing process that increases product yield or enhances quality is accompanied by the risk of changing the product. It is therefore essential that close attention is paid to tracking variation throughout the development process at every stage.

A substantial amount of early stage development is still being performed using outdated, non-commercially viable platforms and transferring processes to new platforms is required. To achieve manufacturing platform advancement, the product needs to be very well characterized during development so that investigators can generate data sets which demonstrate comparability between products used in clinical studies and those generated with the final manufacturing process.

Cost of Goods

COGs associated with manufacturing any drug product impacts the overall price of the therapy and heavily influences the profit margin realized by gene therapy manufactures. High production cost is a challenge that affects profitability. This is reflected in the high costs associated with newly approved gene therapy drugs such as Yescarta♦, Kymriah♦ and Luxturna♦ which are currently priced in the 100 thousands dollar range per dose. The challenge becomes a critical concern when the product in development cannot be sold at a price high enough to achieve a commercially-viable profit margin.  If acceptable margins cannot be reached, developers may choose to terminate production making the drug unavailable to patients. However, due to the remarkable value and life changing nature of the treatments the entire industry is committed to the pursuit of cost effective methods for manufacturing. There is a significant effort that has been mounted by all players to reach this end.

Currently, the main cost contributor to the overall COGs for gene therapy products is high quality clinical grade plasmid DNA containing the therapeutic gene of interest. This reagent is required for transient transfection of cells and it is imperative that the reagent is of high quality. It is an essential component of the process to assure an acceptable safety profile. Another example of an expensive gene therapy product is Zolgensma♦. This new drug was recently approved for the treatment of spinal muscular atrophy (SMA), which is a rare disease that causes severe muscle weakness for suffers. It affects their ability to breath, speak and move. Most babies born with a common form of SMA die by the time they reach two years of age. Currently there is no cure. Zolgensma represents the only treatment option now available to cure the 10,000 – 25,000 affected individuals in the US. However, the current challenge with this therapy is that it could costs $2.1 million per patient1.

Reimbursement

Market size is an important factor that can limit effective commercial return. If the market size is too small, profitability is limited due to the small number of doses required to treat the patient population. This decreases the profit margin realized by the drug developer and can lower motivation to commercialize the therapy. The most encouraging aspect of the gene therapy revolution is that the first round of gene therapy products has been developed for extremely rare diseases, with small patient populations indicating the commitment to treat previously untreatable diseases. Amazingly, these patients can be cured by a single drug application, however, this inherent property of the therapy can further limit commercial profitability. Patients are often not required to pay for these high-cost medicines themselves, and look to government programs and health care insurance providers to reimburse the manufacturer for treatments. Health insurance reimbursement plans for new products is challenging, particularly so for new category products like gene therapy. It is expected that the process of reimbursement will differ from country to country and it will also be guided by factors like economics, demographic data and politics. If the current cost of manufacturing stands then drugs such as Zolgensma could place a huge financial strain on health systems. In the US for example, it is surmised that treating common diseases such as hemophilia, which affects around 20,000 people in the US alone, could cause a financial crisis1. If we look to the future of modern medicine, commercialization of gene therapies will require not only significant advancement in manufacturing processes to reduce costs but also a practical reimbursement strategy that will allow for drug developers to continue to forge into the new frontiers of medicine.

References:

1. Business Insider. http://www.businessinsider.com/gene-therapy-treats-disease-but-prices-could-strain-us-health-system-2019-2 

♦Kymriah is a trademark of Novartis AG., Luxturna is a trademark of Spark Therapeutics, Inc., Yescarta is a trademark of Kite Pharma, Inc., Zolgensma is a trademark of AveXis Inc.

Author Details:

Dr. Mark Szczypka

Global Director, Process Development Services

Pall Corporation

https://www.pall.com/

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Gene Therapy could be a Boon to Alzheimer’s disease (AD): A first-in-human clinical trial proposed

Reporter: Dr. Premalata Pati, Ph.D., Postdoc

A recent research work performed by the Researchers at the University of California San Diego School of Medicine has shared their first-in-human Phase I clinical trial to assess the safety and viability of gene therapy to deliver a key protein into the brains of persons with Alzheimer’s Disease (AD) or Mild Cognitive Impairment (MCI), a condition that often precedes full-blown dementia.  

Mark Tuszynski, M.D., Ph.D., Professor of Neuroscience and Director of the Translational Neuroscience Institute at UC San Diego and team predicted that Gene therapy could be a boon to potential treatments for the disorders like AD and MCI.

The study provides an insight into the genetic source of these mental diseases.

The roots of mental disorders have remained an enigma for so many years. Alzheimer’s disease (AD) is an irreversible, progressive brain disorder that slowly destroys memory and thinking skills and, eventually, the ability to carry out the simplest tasks. AD is a neurodegenerative condition. A buildup of plaques and tangles in the brain, along with cell death, causes memory loss and cognitive decline. In most people with the disease, those with the late-onset type – symptoms first appear in their mid-60s. Alzheimer’s disease is the mostly appearing type of dementia in patients.

Drawing comparing a normal aged brain (left) and the brain of a person with Alzheimer’s (right).
Image Source: https://en.wikipedia.org/wiki/Alzheimer%27s_disease

What the study impart?

Despite decades of effort and billions of dollars of research investment, there are just mere two symptomatic treatments for AD. There is no cure or approved way to slow or stop the progression of the neurological disorder that afflicts more than 5 million Americans and is the sixth leading cause of death in the United States.

Prof. Tuszynski said gene therapy has been tested on multiple diseases and conditions, represents a different approach to a disease that requires new ways of thinking about the disease and new attempts at treatments.

The research team found that delivering the BDNF to the part of the brain that is affected earliest in Alzheimer’s disease; the entorhinal cortex and hippocampus – was able to protect from ongoing cell degeneration by reversing the loss of connections. “These trials were observed in aged rats, amyloid mice, and aged monkeys.”

The protein, called Brain-Derived Neurotrophic Factor or BDNF, a family of growth factors found in the Brain and Central Nervous System that support the survival of existing neurons and promote growth and differentiation of new neurons and synapses. BDNF is especially important in brain regions susceptible to degeneration in AD. It is normally produced throughout life in the entorhinal cortex, an important memory center in the brain and one of the first places where the effects of AD typically appear in the form of short-term memory loss. Persons with AD have diminished levels of BDNF.

However, BDNF is a large molecule and cannot pass through the Blood-Brain Barrier. As a solution, researchers will use gene therapy in which a harmless Adeno-Associated Virus (AAV2) is modified to carry the BDNF gene and injected directly into targeted regions of the brain, where researchers hope it will prompt the production of therapeutic BDNF in nearby cells.

Precautions were taken precisely in injecting the patient to avoid exposure to surrounding degenerating neurons since freely circulating BDNF can cause adverse effects, such as seizures or epileptic conditions.

The recent research and study speculate a safe and feasible assessment of the AAV2-BDNF pathway in humans. A previous gene therapy trial from 2001 to 2012 using AAV2 and a different protein called Nerve Growth Factor (NGF) was carried out by Prof. Tuszynski and team where they observed immense growth, axonal sprouting, and activation of functional markers in the brains of participants.

He also shared that “The BDNF gene therapy trial in AD represents an advancement over the earlier NGF trial, BDNF is a more potent growth factor than NGF for neural circuits that degenerate in AD. Besides, new methods for delivering BDNF will more effectively deliver and distribute it into the entorhinal cortex and hippocampus.”

The research team hopes that the three-year-long trial will recruit 12 participants with either diagnosed AD or MCI to receive AAV2-BDNF treatment, with another 12 persons serving as comparative controls over that period.

The researchers have plans to build on recent successes of gene therapy in other diseases, including a breakthrough success in the treatment of congenital weakness in infants (spinal muscular atrophy) and blindness (Leber Hereditary Optic Neuropathy, a form of retinitis pigmentosa).”

Main Source

https://www.universityofcalifornia.edu/news/could-gene-therapy-halt-progression-alzheimers-disease-first-human-clinical-trial-will-seek?utm_source=fiat-lux

Related Articles

https://pharmaceuticalintelligence.com/2016/04/21/alzheimers-disease-and-dm/
https://pharmaceuticalintelligence.com/2016/03/21/role-of-infectious-agent-in-alzheimers-disease/
https://pharmaceuticalintelligence.com/2016/02/15/alzheimers-disease-tau-art-thou-or-amyloid/

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2021 Virtual World Medical Innovation Forum, Mass General Brigham, Gene and Cell Therapy, VIRTUAL May 19–21, 2021

 

The 2021 Virtual World Medical Innovation Forum will focus on the growing impact of gene and cell therapy.
Senior healthcare leaders from all over look to shape and debate the area of gene and cell therapy. Our shared belief: no matter the magnitude of change, responsible healthcare is centered on a shared commitment to collaborative innovation–industry, academia, and practitioners working together to improve patients’ lives.

https://worldmedicalinnovation.org/agenda/

Virtual | May 19–21, 2021

 

 

Leaders in Pharmaceutical Business Intelligence (LPBI) Group

will cover the event in Real Time

 

Aviva Lev-Ari, PhD, RN

Founder LPBI 1.0 & LPBI 2.0

will be in attendance producing the e-Proceedings

and the Tweet Collection of this Global event expecting +15,000 attendees

 

 

LPBI’s Eighteen Books in Medicine

https://lnkd.in/ekWGNqA

Among them, books on Gene and Cell Therapy include the following:

 

 

Topics

The 2021 Forum will be held virtually and focus on gene and cell therapy.

AAV | Ophthalmology, Otology and Neurology

Gene Therapy | Oncolytic Viruses

CAR- T | Cellular Therapies

Stem Cells | Neurodegenerative Diseases, Regenerative Medicine

GCT | Infectious Disease, Hematology and Diabetes

Gene Editing | RNA Technologies

GCT Manufacturing | Supply Chain

Equity and Access | Emerging GCT Environment

GCT Investor Priorities

Putting GCT to Work | Payers, Providers | Regulatory

*Our agenda is currently under formation and is subject to change. Please continue checking for a more up to date agenda.

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Inhibitory CD161 receptor recognized as a potential immunotherapy target in glioma-infiltrating T cells by single-cell analysis

Reporter: Dr. Premalata Pati, Ph.D., Postdoc

 

Brain tumors, especially the diffused Gliomas are of the most devastating forms of cancer and have so-far been resistant to immunotherapy. It is comprehended that T cells can penetrate the glioma cells, but it still remains unknown why infiltrating cells miscarry to mount a resistant reaction or stop the tumor development.

Gliomas are brain tumors that begin from neuroglial begetter cells. The conventional therapeutic methods including, surgery, chemotherapy, and radiotherapy, have accomplished restricted changes inside glioma patients. Immunotherapy, a compliance in cancer treatment, has introduced a promising strategy with the capacity to penetrate the blood-brain barrier. This has been recognized since the spearheading revelation of lymphatics within the central nervous system. Glioma is not generally carcinogenic. As observed in a number of cases, the tumor cells viably reproduce and assault the adjoining tissues, by and large, gliomas are malignant in nature and tend to metastasize. There are four grades in glioma, and each grade has distinctive cell features and different treatment strategies. Glioblastoma is a grade IV glioma, which is the crucial aggravated form. This infers that all glioblastomas are gliomas, however, not all gliomas are glioblastomas.

Decades of investigations on infiltrating gliomas still take off vital questions with respect to the etiology, cellular lineage, and function of various cell types inside glial malignancies. In spite of the available treatment options such as surgical resection, radiotherapy, and chemotherapy, the average survival rate for high-grade glioma patients remains 1–3 years (1).

A recent in vitro study performed by the researchers of Dana-Farber Cancer Institute, Massachusetts General Hospital, and the Broad Institute of MIT and Harvard, USA, has recognized that CD161 is identified as a potential new target for immunotherapy of malignant brain tumors. The scientific team depicted their work in the Cell Journal, in a paper entitled, “Inhibitory CD161 receptor recognized in glioma-infiltrating T cells by single-cell analysis.” on 15th February 2021.

To further expand their research and findings, Dr. Kai Wucherpfennig, MD, PhD, Chief of the Center for Cancer Immunotherapy, at Dana-Farber stated that their research is additionally important in a number of other major human cancer types such as 

  • melanoma,
  • lung,
  • colon, and
  • liver cancer.

Dr. Wucherpfennig has praised the other authors of the report Mario Suva, MD, PhD, of Massachusetts Common Clinic; Aviv Regev, PhD, of the Klarman Cell Observatory at Broad Institute of MIT and Harvard, and David Reardon, MD, clinical executive of the Center for Neuro-Oncology at Dana-Farber.

Hence, this new study elaborates the effectiveness of the potential effectors of anti-tumor immunity in subsets of T cells that co-express cytotoxic programs and several natural killer (NK) cell genes.

The Study-

IMAGE SOURCE: Experimental Strategy (Mathewson et al., 2021)

 

The group utilized single-cell RNA sequencing (RNA-seq) to mull over gene expression and the clonal picture of tumor-infiltrating T cells. It involved the participation of 31 patients suffering from diffused gliomas and glioblastoma. Their work illustrated that the ligand molecule CLEC2D activates CD161, which is an immune cell surface receptor that restrains the development of cancer combating activity of immune T cells and tumor cells in the brain. The study reveals that the activation of CD161 weakens the T cell response against tumor cells.

Based on the study, the facts suggest that the analysis of clonally expanded tumor-infiltrating T cells further identifies the NK gene KLRB1 that codes for CD161 as a candidate inhibitory receptor. This was followed by the use of 

  • CRISPR/Cas9 gene-editing technology to inactivate the KLRB1 gene in T cells and showed that CD161 inhibits the tumor cell-killing function of T cells. Accordingly,
  • genetic inactivation of KLRB1 or
  • antibody-mediated CD161 blockade

enhances T cell-mediated killing of glioma cells in vitro and their anti-tumor function in vivo. KLRB1 and its associated transcriptional program are also expressed by substantial T cell populations in other forms of human cancers. The work provides an atlas of T cells in gliomas and highlights CD161 and other NK cell receptors as immune checkpoint targets.

Further, it has been identified that many cancer patients are being treated with immunotherapy drugs that disable their “immune checkpoints” and their molecular brakes are exploited by the cancer cells to suppress the body’s defensive response induced by T cells against tumors. Disabling these checkpoints lead the immune system to attack the cancer cells. One of the most frequently targeted checkpoints is PD-1. However, recent trials of drugs that target PD-1 in glioblastomas have failed to benefit the patients.

In the current study, the researchers found that fewer T cells from gliomas contained PD-1 than CD161. As a result, they said, “CD161 may represent an attractive target, as it is a cell surface molecule expressed by both CD8 and CD4 T cell subsets [the two types of T cells engaged in response against tumor cells] and a larger fraction of T cells express CD161 than the PD-1 protein.”

However, potential side effects of antibody-mediated blockade of the CLEC2D-CD161 pathway remain unknown and will need to be examined in a non-human primate model. The group hopes to use this finding in their future work by

utilizing their outline by expression of KLRB1 gene in tumor-infiltrating T cells in diffuse gliomas to make a remarkable contribution in therapeutics related to immunosuppression in brain tumors along with four other common human cancers ( Viz. melanoma, non-small cell lung cancer (NSCLC), hepatocellular carcinoma, and colorectal cancer) and how this may be manipulated for prevalent survival of the patients.

References

(1) Anders I. Persson, QiWen Fan, Joanna J. Phillips, William A. Weiss, 39 – Glioma, Editor(s): Sid Gilman, Neurobiology of Disease, Academic Press, 2007, Pages 433-444, ISBN 9780120885923, https://doi.org/10.1016/B978-012088592-3/50041-4.

Main Source

Mathewson ND, Ashenberg O, Tirosh I, Gritsch S, Perez EM, Marx S, et al. 2021. Inhibitory CD161 receptor identified in glioma-infiltrating T cells by single-cell analysis. Cell.https://www.cell.com/cell/fulltext/S0092-8674(21)00065-9?elqTrackId=c3dd8ff1d51f4aea87edd0153b4f2dc7

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VIDEOS on Cancer Biology, Cancer Genetics, Cancer Immunotherapy

19th Annual Koch Institute Summer Symposium on Cancer Immunotherapy, June 12, 2020 at MIT’s Kresge Auditorium

 

Other related articles published in this Open Access Online Scientific Journal include the following:

 

Single Cell Sequencing:

Part 4.1 in Genomics Volume 2

Latest in Genomics Methodologies for Therapeutics: Gene Editing, NGS & BioInformatics, Simulations and the Genome Ontology 

On Amazon.com since 12/28/2019

https://www.amazon.com/dp/B08385KF87

 

4.1.3   Single-cell Genomics: Directions in Computational and Systems Biology – Contributions of Prof. Aviv Regev @Broad Institute of MIT and Harvard, Cochair, the Human Cell Atlas Organizing Committee with Sarah Teichmann of the Wellcome Trust Sanger Institute

Curator: Aviva Lev-Ari, PhD, RN

https://pharmaceuticalintelligence.com/2018/09/03/single-cell-genomics-directions-in-computational-and-systems-biology-contributions-of-ms-aviv-regev-phd-broad-institute-of-mit-and-harvard-cochair-the-human-cell-atlas-organizing-committee-wit/

 

4.1.4   Cellular Genetics

https://www.sanger.ac.uk/science/programmes/cellular-genetics

 

4.1.5   Cellular Genomics

https://www.garvan.org.au/research/cellular-genomics

 

4.1.6   SINGLE CELL GENOMICS 2019 – sometimes the sum of the parts is greater than the whole, September 24-26, 2019, Djurönäset, Stockholm, Sweden http://www.weizmann.ac.il/conferences/SCG2019/single-cell-genomics-2019

Reporter: Aviva Lev-Ari, PhD, RN

https://pharmaceuticalintelligence.com/2019/05/29/single-cell-genomics-2019-september-24-26-2019-djuronaset-stockholm-sweden/

 

4.1.7   Norwich Single-Cell Symposium 2019, Earlham Institute, single-cell genomics technologies and their application in microbial, plant, animal and human health and disease, October 16-17, 2019, 10AM-5PM

Reporter: Aviva Lev-Ari, PhD, RN

https://pharmaceuticalintelligence.com/2019/06/04/norwich-single-cell-symposium-2019-earlham-institute-single-cell-genomics-technologies-and-their-application-in-microbial-plant-animal-and-human-health-and-disease-october-16-17-2019-10am-5pm/

 

4.1.8   Newly Found Functions of B Cell

Reporter and Curator: Dr. Sudipta Saha, Ph.D.

https://pharmaceuticalintelligence.com/2019/05/23/newly-found-functions-of-b-cell/

 

4.1.9 RESEARCH HIGHLIGHTS: HUMAN CELL ATLAS

https://www.broadinstitute.org/research-highlights-human-cell-atlas

 

CRISPR – 200 articles in the Journal

 

Chapter 21 in Genomics Volume 1

Genomics Orientations for Personalized Medicine. On Amazon.com since 11/23/2015

http://www.amazon.com/dp/B018DHBUO6

 

Glioblastoma – 150 articles in the Journal

Most recent

 

Immunotherapy may help in glioblastoma survival

Reporter and Curator: Dr. Sudipta Saha, Ph.D.

https://pharmaceuticalintelligence.com/2019/03/16/immunotherapy-may-help-in-glioblastoma-survival/

 

New Treatment in Development for Glioblastoma: Hopes for Sen. John McCain

Reporter: Aviva Lev-Ari, PhD, RN

https://pharmaceuticalintelligence.com/2017/07/25/new-treatment-in-development-for-glioblastoma-hopes-for-sen-john-mccain/

 

Funding Oncorus’s Immunotherapy Platform: Next-generation Oncolytic Herpes Simplex Virus (oHSV) for Brain Cancer, Glioblastoma Multiforme (GBM)

Reporter: Aviva Lev-Ari, PhD, RN

https://pharmaceuticalintelligence.com/2016/12/28/funding-oncoruss-immunotherapy-platform-next-generation-oncolytic-herpes-simplex-virus-ohsv-for-brain-cancer-glioblastoma-multiforme-gbm/

 

Glioma, Glioblastoma and Neurooncology

Curator: Larry H. Bernstein, MD, FCAP

https://pharmaceuticalintelligence.com/2015/10/19/glioma-glioblastoma-and-neurooncology/

 

Positron Emission Tomography (PET) and Near-Infrared Fluorescence Imaging:  Noninvasive Imaging of Cancer Stem Cells (CSCs)  monitoring of AC133+ glioblastoma in subcutaneous and intracerebral xenograft tumors

Reporter: Aviva Lev-Ari, PhD, RN

https://pharmaceuticalintelligence.com/2014/01/29/positron-emission-tomography-pet-and-near-infrared-fluorescence-imaging-noninvasive-imaging-of-cancer-stem-cells-cscs-monitoring-of-ac133-glioblastoma-in-subcutaneous-and-intracerebral-xenogra/

 

Gamma Linolenic Acid (GLA) as a Therapeutic tool in the Management of Glioblastoma

Eric Fine* (1), Mike Briggs* (1,2), Raphael Nir# (1,2,3)

https://pharmaceuticalintelligence.com/2013/07/15/gamma-linolenic-acid-gla-as-a-therapeutic-tool-in-the-management-of-glioblastoma/

 

 

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Cancer treatment using CRISPR-based Genome Editing System 

Reporter: Irina Robu, PhD

CRISPR, stands for “clusters of regularly interspaced short palindromic repeats” is one of the biggest accomplishments in science of this decade and it is the simplest tool for altering DNA sequences and modifying gene functions. The technology is adapted form the natural defense mechanism of bacteria. Bacteria uses CRISPR-derived RNA and different Cas proteins to foil attacks by viruses and foreign bodies.

Scientists in the laboratory of Prof. Dan Peer, VP for R&D and Head of the Laboratory of Precision Nanomedicine at the Shmunis School of Biomedicine and Cancer Research at TAU  have shown that CRISPR/Cas9 system is efficient in treating metastatic cancer. They developed a novel lipid nanoparticle-based delivery system that targets cancer cells and ends them by genetic manipulation, called CRISPR-LNPs, which were published in published in November 2020 in Science Advances.

Professor Peer and his team of scientists chose two of the deadliest cancers: glioblastoma and metastatic ovarian cancer to prove that CRISPR genome editing system can be used to treat cancer effectively in a living animal. Since, glioblastoma is the most aggressive type of brain cancer with a life expectancy of 15 months after diagnosis, the researchers showed that the single treatment with CRISPR-LNPs doubled the average life expectancy of mice with glioblastoma tumors.  At the same time, ovarian cancer is the most lethal cancer of female reproductive system and many patients are usually diagnosed at the advance stage of the disease. Treatment with CRISPR-LNPs in a metastatic ovarian cancer mice model increased their overall survival rate by 80%.

Despite CRISPR genome editing technology being capable of identifying and altering  any genetic segment, clinical implementation is still in its infancy because the inability to accurately deliver the CRISPR to the target cells.  In order to solve the issue, Professor Peer developed a delivery system that targets the DNA responsible for the cancer cells.

By demonstrating that the technology can treat two aggressive cancers, researchers open the technology to numerous new possibilities for treating other types of cancer. They intend to go on to experiments with blood cancers which are very interesting genetically.

SOURCE

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The Nobel Prize in Chemistry 2020: Emmanuelle Charpentier & Jennifer A. Doudna

Reporters: Stephen J. Williams, Ph.D. and Aviva Lev-Ari, PhD, RN

 

UPDATED on 11/12/2020

Harvard’s Jack Szostak congratulates former advisee Jennifer Doudna

It was a toast from one Nobel laureate to another, sweetened by the pride of a mentor to a prized student.

When Jennifer Doudna Ph.D. ’89 was honored on Wednesday with the Nobel Prize in chemistry for her work on the CRISPR gene-editing technique, she became the second person to gain such an honor from the lab of Jack Szostak, a genetics professor at Harvard Medical School and Massachusetts General Hospital, and professor of chemistry and chemical biology at Harvard’s Faculty of Arts and Sciences.

Szostak, who won the Nobel Prize in physiology or medicine in 2009 for work on how telomere caps keep the body’s chromosomes from breaking down, advised Doudna’s doctoral work on RNA and on Wednesday raised a glass in honor of Doudna, now at the University of California, Berkeley. In a tweet, Szostak expressed his delight at seeing someone he once guided through her early scientific steps soar to science’s highest reaches:

Doudna received the prize together with Emmanuelle Charpentier, for their work discovering and developing CRISPR as a precise gene-editing tool. In just the eight years since the pair announced their discovery the use of the technique has rapidly spread to a host of fields, allowing researchers to alter the code of life and develop resistant crops, new medical therapies, and even anticipate curing inherited diseases.

 

UPDADTED on 11/2/2020

 

Announcement of the Nobel Prize in Chemistry 2020

Live webcast from the press conference where the Royal Swedish Academy of Sciences will announce the Nobel Prize in Chemistry 2020.

 

 

The Royal Swedish Academy of Sciences has decided to award the Nobel Prize in Chemistry 2020 to

Emmanuelle Charpentier
Max Planck Unit for the Science of Pathogens, Berlin, Germany

Jennifer A. Doudna
University of California, Berkeley, USA

“for the development of a method for genome editing”

Genetic scissors: a tool for rewriting the code of life

Emmanuelle Charpentier and Jennifer A. Doudna have discovered one of gene technology’s sharpest tools: the CRISPR/Cas9 genetic scissors. Using these, researchers can change the DNA of animals, plants and microorganisms with extremely high precision. This technology has had a revolutionary impact on the life sciences, is contributing to new cancer therapies and may make the dream of curing inherited diseases come true.

Researchers need to modify genes in cells if they are to find out about life’s inner workings. This used to be time-consuming, difficult and sometimes impossible work. Using the CRISPR/Cas9 genetic scissors, it is now possible to change the code of life over the course of a few weeks.

“There is enormous power in this genetic tool, which affects us all. It has not only revolutionised basic science, but also resulted in innovative crops and will lead to ground-breaking new medical treatments,” says Claes Gustafsson, chair of the Nobel Committee for Chemistry.

As so often in science, the discovery of these genetic scissors was unexpected. During Emmanuelle Charpentier’s studies of Streptococcus pyogenes, one of the bacteria that cause the most harm to humanity, she discovered a previously unknown molecule, tracrRNA. Her work showed that tracrRNA is part of bacteria’s ancient immune system, CRISPR/Cas, that disarms viruses by cleaving their DNA.

Charpentier published her discovery in 2011. The same year, she initiated a collaboration with Jennifer Doudna, an experienced biochemist with vast knowledge of RNA. Together, they succeeded in recreating the bacteria’s genetic scissors in a test tube and simplifying the scissors’ molecular components so they were easier to use.

In an epoch-making experiment, they then reprogrammed the genetic scissors. In their natural form, the scissors recognise DNA from viruses, but Charpentier and Doudna proved that they could be controlled so that they can cut any DNA molecule at a predetermined site. Where the DNA is cut it is then easy to rewrite the code of life.

Since Charpentier and Doudna discovered the CRISPR/Cas9 genetic scissors in 2012 their use has exploded. This tool has contributed to many important discoveries in basic research, and plant researchers have been able to develop crops that withstand mould, pests and drought. In medicine, clinical trials of new cancer therapies are underway, and the dream of being able to cure inherited diseases is about to come true. These genetic scissors have taken the life sciences into a new epoch and, in many ways, are bringing the greatest benefit to humankind.

Illustrations

The illustrations are free to use for non-commercial purposes. Attribute ”© Johan Jarnestad/The Royal Swedish Academy of Sciences”

Illustration: Using the genetic scissors (pdf)
Illustration: Streptococcus’ natural immune system against viruses:CRISPR/Cas9 pdf)
Illustration: CRISPR/Cas9 genetic scissors (pdf)

Read more about this year’s prize

Popular information: Genetic scissors: a tool for rewriting the code of life (pdf)
Scientific Background: A tool for genome editing (pdf)

Emmanuelle Charpentier, born 1968 in Juvisy-sur-Orge, France. Ph.D. 1995 from Institut Pasteur, Paris, France. Director of the Max Planck Unit for the Science of Pathogens, Berlin, Germany.

Jennifer A. Doudna, born 1964 in Washington, D.C, USA. Ph.D. 1989 from Harvard Medical School, Boston, USA. Professor at the University of California, Berkeley, USA and Investigator, Howard Hughes Medical Institute.

SOURCE

https://www.nobelprize.org/prizes/chemistry/2020/press-release/

 

Nobel Prize in Chemistry awarded to scientists who discovered CRISPR gene editing tool for ‘rewriting the code of life’

(CNN)The Nobel Prize in Chemistry has been awarded to Emmanuelle Charpentier and Jennifer A. Doudna for the development of a method for genome editing.

They discovered one of gene technology’s sharpest tools: the CRISPR/Cas9 genetic scissors. Using these, researchers can change the DNA of animals, plants and micro-organisms with extremely high precision.
Before announcing the winners on Wednesday, Göran K. Hansson, secretary-general for the Royal Swedish Academy of Sciences, said that this year’s prize was about “rewriting the code of life.”
The American biochemist Jennifer A. Doudna (left) and French microbiologist Emmanuelle Charpentier, pictured together in 2016.
 
The CRISPR/Cas9 gene editing tools have revolutionized the molecular life sciences, brought new opportunities for plant breeding, are contributing to innovative cancer therapies and may make the dream of curing inherited diseases come true, according to a press release from the Nobel committee.
 
 
There have also been some ethical concerns around the CRISPR technology, however.
Charpentier, a French microbiologist, and Doudna, an American biochemist, are the first women to jointly win the Nobel Prize in Chemistry, and the sixth and seventh women to win the chemistry prize.
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Jennifer Doudna wins 2020 Nobel Prize in chemistry

 

First Day in a Nobel Life: Jennifer Doudna

12,365 views
Oct 7, 2020
 
Scenes from day that UC Berkeley Professor Jennifer Doudna won the Nobel Prize For the full story, visit: https://news.berkeley.edu/2020/10/07/… University of California, Berkeley, biochemist Jennifer Doudna today won the 2020 Nobel Prize in Chemistry, sharing it with colleague Emmanuelle Charpentier for the co-development of CRISPR-Cas9, a genome editing breakthrough that has revolutionized biomedicine. CRISPR-Cas9 allows scientists to rewrite DNA — the code of life — in any organism, including human cells, with unprecedented efficiency and precision. The groundbreaking power and versatility of CRISPR-Cas9 has opened up new and wide-ranging possibilities across biology, agriculture and medicine, including the treatment of thousands of intractable diseases. Doudna and Charpentier, director of the Max Planck Institute for Infection Biology, will share the 10 million Swedish krona (more than $1 million) prize. “This great honor recognizes the history of CRISPR and the collaborative story of harnessing it into a profoundly powerful engineering technology that gives new hope and possibility to our society,” said Doudna. “What started as a curiosity‐driven, fundamental discovery project has now become the breakthrough strategy used by countless researchers working to help improve the human condition. I encourage continued support of fundamental science as well as public discourse about the ethical uses and responsible regulation of CRISPR technology.” Video by Clare Major & Roxanne Makasdjian
SOURCE

 

Jennifer Doudna wins 2020 Nobel Prize in chemistry

 

Jennifer Doudna in the PBS Movie CRISPR

Our critically-acclaimed documentary HUMAN NATURE is now streaming on NETFLIX. #HumanNatureFilm. Find out more about the film on our website.

 

Other Articles on the Nobel Prize in this Open Access Journal Include:

2020 Nobel Prize for Physiology and Medicine for Hepatitis C Discovery goes to British scientist Michael Houghton and US researchers Harvey Alter and Charles Rice

CONTAGIOUS – About Viruses, Pandemics and Nobel Prizes at the Nobel Prize Museum, Stockholm, Sweden 

AACR Congratulates Dr. William G. Kaelin Jr., Sir Peter J. Ratcliffe, and Dr. Gregg L. Semenza on 2019 Nobel Prize in Physiology or Medicine

2018 Nobel Prize in Physiology or Medicine for contributions to Cancer Immunotherapy to James P. Allison, Ph.D., of the University of Texas, M.D. Anderson Cancer Center, Houston, Texas. Dr. Allison shares the prize with Tasuku Honjo, M.D., Ph.D., of Kyoto University Institute, Japan

2017 Nobel prize in chemistry given to Jacques Dubochet, Joachim Frank, and Richard Henderson  for developing cryo-electron microscopy

2016 Nobel Prize in Chemistry awarded for development of molecular machines, the world’s smallest mechanical devices, the winners: Jean-Pierre Sauvage, J. Fraser Stoddart and Bernard L. Feringa

Correspondence on Leadership in Genomics and other Gene Curations: Dr. Williams with Dr. Lev-Ari

Programming life: An interview with Jennifer Doudna by Michael Chui, a partner of the McKinsey Global Institute

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Prime Editing as a New CRISPR Tool to Enhance Precision and Versatility

 

Reporter: Stephen J. Williams, PhD

 

CRISPR has become a powerful molecular for the editing of genomes tool in research, drug discovery, and the clinic

(see posts and ebook on this site below)

 

however, as discussed on this site

(see posts below)

there have been many instances of off-target effects where genes, other than the selected target, are edited out.  This ‘off-target’ issue has hampered much of the utility of CRISPR in gene-therapy and CART therapy

see posts

 

However, an article in Science by Jon Cohen explains a Nature paper’s finding of a new tool in the CRISPR arsenal called prime editing, meant to increase CRISPR specificity and precision editing capabilities.

PRIME EDITING PROMISES TO BE A CUT ABOVE CRISPR

By Jon Cohen | Oct 25th, 2019

Prime editing promises to be a cut above CRISPR Jon Cohen CRISPR, an extraordinarily powerful genome-editing tool invented in 2012, can still be clumsy. … Prime editing steers around shortcomings of both techniques by heavily modifying the Cas9 protein and the guide RNA. … ” Prime editing “well may become the way that disease-causing mutations are repaired,” he says.

Science Vol. 366, No. 6464; DOI: 10.1126/science.366.6464.406

The effort, led by Drs. David Liu and Andrew Anzalone at the Broad Institute (Cambridge, MA), relies on the modification of the Cas9 protein and guide RNA, so that there is only a nick in a single strand of the double helix.  The canonical Cas9 cuts both strands of DNA, and so relies on an efficient gap repair activity of the cell.  The second part, a new type of guide RNA called a pegRNA, contains an RNA template for a new DNA sequence to be added at the target location.  This pegRNA-directed synthesis of the new template requires the attachment of a reverse transcriptase enzymes to the Cas9.  So far Liu and his colleagues have tested the technology on over 175 human and rodent cell lines with great success.  In addition, they had also corrected mutations which cause Tay Sachs disease, which previous CRISPR systems could not do.  Liu claims that this technology could correct over 89% of pathogenic variants in human diseases.

A company Prime Medicine has been formed out of this effort.

Source: https://science.sciencemag.org/content/366/6464/406.abstract

 

Read an article on Dr. Liu, prime editing, and the companies that Dr. Liu has initiated including Editas Medicine, Beam Therapeutics, and Prime Medicine at https://www.statnews.com/2019/11/06/questions-david-liu-crispr-prime-editing-answers/

(interview by StatNews  SHARON BEGLEY @sxbegle)

As was announced, prime editing for human therapeutics will be jointly developed by both Prime Medicine and Beam Therapeutics, each focusing on different types of edits and distinct disease targets, which will help avoid redundancy and allow us to cover more disease territory overall. The companies will also share knowledge in prime editing as well as in accompanying technologies, such as delivery and manufacturing.

Reader of StatNews.: Can you please compare the pros and cons of prime editing versus base editing?

The first difference between base editing and prime editing is that base editing has been widely used for the past 3 1/2 years in organisms ranging from bacteria to plants to mice to primates. Addgene tells me that the DNA blueprints for base editors from our laboratory have been distributed more than 7,500 times to more than 1,000 researchers around the world, and more than 100 research papers from many different laboratories have been published using base editors to achieve desired gene edits for a wide variety of applications. While we are very excited about prime editing, it’s brand-new and there has only been one paper published thus far. So there’s much to do before we can know if prime editing will prove to be as general and robust as base editing has proven to be.

We directly compared prime editors and base editors in our study, and found that current base editors can offer higher editing efficiency and fewer indel byproducts than prime editors, while prime editors offer more targeting flexibility and greater editing precision. So when the desired edit is a transition point mutation (C to T, T to C, A to G, or G to A), and the target base is well-positioned for base editing (that is, a PAM sequence exists approximately 15 bases from the target site), then base editing can result in higher editing efficiencies and fewer byproducts. When the target base is not well-positioned for base editing, or when other “bystander” C or A bases are nearby that must not be edited, then prime editing offers major advantages since it does not require a precisely positioned PAM sequence and is a true “search-and-replace” editing capability, with no possibility of unwanted bystander editing at neighboring bases.

Of course, for classes of mutations other than the four types of point mutations that base editors can make, such as insertions, deletions, and the eight other kinds of point mutations, to our knowledge prime editing is currently the only approach that can make these mutations in human cells without requiring double-stranded DNA cuts or separate DNA templates.

Nucleases (such as the zinc-finger nucleases, TALE nucleases, and the original CRISPR-Cas9), base editors, and prime editors each have complementary strengths and weaknesses, just as scissors, pencils, and word processors each have unique and useful roles. All three classes of editing agents already have or will have roles in basic research and in applications such as human therapeutics and agriculture.

Nature Paper on Prime Editing CRISPR

Search-and-replace genome editing without double-strand breaks or donor DNA (6)

 

Andrew V. Anzalone,  Peyton B. Randolph, Jessie R. Davis, Alexander A. Sousa,

Luke W. Koblan, Jonathan M. Levy, Peter J. Chen, Christopher Wilson,

Gregory A. Newby, Aditya Raguram & David R. Liu

 

Nature volume 576, pages149–157(2019)

 

Abstract

Most genetic variants that contribute to disease1 are challenging to correct efficiently and without excess byproducts2,3,4,5. Here we describe prime editing, a versatile and precise genome editing method that directly writes new genetic information into a specified DNA site using a catalytically impaired Cas9 endonuclease fused to an engineered reverse transcriptase, programmed with a prime editing guide RNA (pegRNA) that both specifies the target site and encodes the desired edit. We performed more than 175 edits in human cells, including targeted insertions, deletions, and all 12 types of point mutation, without requiring double-strand breaks or donor DNA templates. We used prime editing in human cells to correct, efficiently and with few byproducts, the primary genetic causes of sickle cell disease (requiring a transversion in HBB) and Tay–Sachs disease (requiring a deletion in HEXA); to install a protective transversion in PRNP; and to insert various tags and epitopes precisely into target loci. Four human cell lines and primary post-mitotic mouse cortical neurons support prime editing with varying efficiencies. Prime editing shows higher or similar efficiency and fewer byproducts than homology-directed repair, has complementary strengths and weaknesses compared to base editing, and induces much lower off-target editing than Cas9 nuclease at known Cas9 off-target sites. Prime editing substantially expands the scope and capabilities of genome editing, and in principle could correct up to 89% of known genetic variants associated with human diseases.

 

 

From Anzolone et al. Nature 2019 Figure 1.

Prime editing strategy

Cas9 targets DNA using a guide RNA containing a spacer sequence that hybridizes to the target DNA site. We envisioned the generation of guide RNAs that both specify the DNA target and contain new genetic information that replaces target DNA nucleotides. To transfer information from these engineered guide RNAs to target DNA, we proposed that genomic DNA, nicked at the target site to expose a 3′-hydroxyl group, could be used to prime the reverse transcription of an edit-encoding extension on the engineered guide RNA (the pegRNA) directly into the target site (Fig. 1b, cSupplementary Discussion).

These initial steps result in a branched intermediate with two redundant single-stranded DNA flaps: a 5′ flap that contains the unedited DNA sequence and a 3′ flap that contains the edited sequence copied from the pegRNA (Fig. 1c). Although hybridization of the perfectly complementary 5′ flap to the unedited strand is likely to be thermodynamically favoured, 5′ flaps are the preferred substrate for structure-specific endonucleases such as FEN122, which excises 5′ flaps generated during lagging-strand DNA synthesis and long-patch base excision repair. The redundant unedited DNA may also be removed by 5′ exonucleases such as EXO123.

  • The authors reasoned that preferential 5′ flap excision and 3′ flap ligation could drive the incorporation of the edited DNA strand, creating heteroduplex DNA containing one edited strand and one unedited strand (Fig. 1c).
  • DNA repair to resolve the heteroduplex by copying the information in the edited strand to the complementary strand would permanently install the edit (Fig. 1c).
  • They had hypothesized that nicking the non-edited DNA strand might bias DNA repair to preferentially replace the non-edited strand.

Results

  • The authors evaluated the eukaryotic cell DNA repair outcomes of 3′ flaps produced by pegRNA-programmed reverse transcription in vitro, and performed in vitro prime editing on reporter plasmids, then transformed the reaction products into yeast cells (Extended Data Fig. 2).
  • Reporter plasmids encoding EGFP and mCherry separated by a linker containing an in-frame stop codon, +1 frameshift, or −1 frameshift were constructed and when plasmids were edited in vitro with Cas9 nickase, RT, and 3′-extended pegRNAs encoding a transversion that corrects the premature stop codon, 37% of yeast transformants expressed both GFP and mCherry (Fig. 1f, Extended Data Fig. 2).
  • They fused a variant of M—MLV-RT (reverse transcriptase) to Cas9 with an extended linker and this M-MLV RT fused to the C terminus of Cas9(H840A) nickase was designated as PE1. This strategy allowed the authors to generate a cell line containing all the required components of the primer editing system. They constructed 19 variants of PE1 containing a variety of RT mutations to evaluate their editing efficiency in human cells
  • Generated a pentamutant RT incorporated into PE1 (Cas9(H840A)–M-MLV RT(D200N/L603W/T330P/T306K/W313F)) is hereafter referred to as prime editor 2 (PE2).  These were more thermostable versions of RT with higher efficiency.
  • Optimized the guide (pegRNA) using a series of permutations and  recommend starting with about 10–16 nt and testing shorter and longer RT templates during pegRNA optimization.
  • In the previous attempts (PE1 and PE2 systems), mismatch repair resolves the heteroduplex to give either edited or non-edited products. So they next developed an optimal editing system (PE3) to produce optimal nickase activity and found nicks positioned 3′ of the edit about 40–90 bp from the pegRNA-induced nick generally increased editing efficiency (averaging 41%) without excess indel formation (6.8% average indels for the sgRNA with the highest editing efficiency) (Fig. 3b).
  • The cell line used to finalize and validate the system was predominantly HEK293T immortalized cell line
  • Together, their findings establish that PE3 systems improve editing efficiencies about threefold compared with PE2, albeit with a higher range of indels than PE2. When it is possible to nick the non-edited strand with an sgRNA that requires editing before nicking, the PE3b system offers PE3-like editing levels while greatly reducing indel formation.
  • Off Target Effects: Strikingly, PE3 or PE2 with the same 16 pegRNAs containing these four target spacers resulted in detectable off-target editing at only 3 out of 16 off-target sites, with only 1 of 16 showing an off-target editing efficiency of 1% or more (Extended Data Fig. 6h). Average off-target prime editing for pegRNAs targeting HEK3HEK4EMX1, and FANCFat the top four known Cas9 off-target sites for each protospacer was <0.1%, <2.2 ± 5.2%, <0.1%, and <0.13 ± 0.11%, respectively (Extended Data Fig. 6h).
  • The PE3 system was very efficient at editing the most common mutation that causes Tay-Sachs disease, a 4-bp insertion in HEXA(HEXA1278+TATC).

References

  1. Landrum, M. J. et al. ClinVar: public archive of interpretations of clinically relevant variants. Nucleic Acids Res44, D862–D868 (2016).
  2. Jinek, M. et al. A programmable dual-RNA-guided DNA endonuclease in adaptive bacterial immunity. Science337, 816–821 (2012).
  3. Cong, L. et al. Multiplex genome engineering using CRISPR/Cas systems. Science339, 819–823 (2013).

 

  1. Mali, P. et al. RNA-guided human genome engineering via Cas9. Science339, 823–826 (2013).
  2. Kosicki, M., Tomberg, K. & Bradley, A. Repair of double-strand breaks induced by CRISPR–Cas9 leads to large deletions and complex rearrangements.  Biotechnol. 36, 765–771 (2018).
  3. Anzalone, A.V., Randolph, P.B., Davis, J.R. et al.Search-and-replace genome editing without double-strand breaks or donor DNA. Nature576, 149–157 (2019). https://doi.org/10.1038/s41586-019-1711-4

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Articles on the Use of single cell analysis in COVID-19 research and A machine learning model that can Predict Base-editing Outcomes

 

Reporter: Aviva Lev-Ari, PhD, RN

 

From: Richard Lumb <contact@frontlinegenomics.com>

Date: July 1, 2020 at 6:05:55 AM EDT

To: avivalev-ari@alum.berkeley.edu

Subject: FLG Newsletter: Single cell analysis in COVID-19 research, a machine learning model that can predict base-editing outcomes & much more

Reply-To: contact@frontlinegenomics.com

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Front Line Genomics Newsletter

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Dear Aviva,

First of all, a big thank you to everyone who attended yesterday’s webinar on a new approach for exploring the dark genome. If you missed it, you can still watch it ‘on demand’ here.

In the last week, we’ve also launched two more webinar series. Both are free to attend and available live or on-demand:

Single Cell Online: A series of 4 webinars in July, starting on the 9th, focusing on unleashing the full power of single cell technologies. The series includes contributors from Novartis, Merck, Sanofi, Roche, the University of Gothenburg, MGI and Partek. Find out more and register here.

Driving FAIR in BioPharma: A series of 3 webinars in July and August, starting on the 21st July, exploring various use cases of FAIR data implementation to enable the potential of AI and ML in R&D. The series features contributors from AstraZeneca, Roche, Novartis, University of Oxford, ONTOFORCE, FDA, Eurofins and CDD. Click here to find out more and register.

Finally, this week on the website we have some fantastic content for you, including articles on the use of single cell analysis in COVID-19 research and a machine learning model that can predict base-editing outcomes. There’s also the latest DNA Today Podcasts focusing on infertility, featuring insights from genetic counsellors and the writer and producer of an explosive genetics mystery sci-fi movie called ANYA (check it out, it’s very thought provoking).

Stay safe everyone. 

Kind Regards,

Rich

Richard Lumb PhD

Founder & CEO

Front Line Genomics

J202, The Biscuit Factory, 100 Drummond Rd, London, SE16 4DG.

T:  +44 (0)208 191 8810

M: +44 (0)7739 251 898

E:  richard@frontlinegenomics.com

W: www.frontlinegenomics.com

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Reporter and Curator: Dr. Sudipta Saha, Ph.D.

 

In-vitro fertilisation (IVF) is now regarded as a huge clinical success which has benefitted an estimated 16 million parents, at the time the development not only sparked moral outrage but led to political and legislative constraints. Patients undergoing IVF may be presented with numerous assisted reproductive treatments purportedly increasing the chances of pregnancy. Such commercialised “IVF add-ons” often come at high costs without clinical evidence of validity. Additionally, long-term studies of children born through IVF have historically been scarce and inconsistent in their data collection. This has meant that potential genetic predispositions, such as increased body fat composition and blood pressure, as well as congenital abnormalities long associated with IVF births, lack proof of causality.

 

With Preimplantation genetic testing mutated embryos are automatically discarded, whereas CRISPR could correct mutations to increase the number of viable embryos for implantation. Moreover, in instances where all embryos in a given cycle are destined to develop with severe or lethal mutations, CRISPR could bring success for otherwise doomed IVF treatments. Genetic screening programs offered to couples in hot-spot areas of carrier frequency of monogenic disorders have had huge success in alleviating regional disease burdens. Carried out since the 1970s these programs have altered the course of natural evolution, but few would dispute their benefits in preventing heritable disease transmission.

 

Mutations are as inevitable as death and taxes. Whilst age is considered one of the largest factors in de-novo mutation generation, it appears that these are inherited primarily from the paternal line. Thus, the paternal age of conception predominantly determines the mutation frequency inherited by children. Whereas advanced maternal age is not associated with mutagenic allele frequency but chromosomal abnormalities. The risk of aneuploidy rises steadily in mothers over the age of 26. Although embryos are screened for aneuploidy prior to implantation, with so many other factors simultaneously being screened the probability of having enough embryos remaining to allow for 50% rate of blastocyte development in-vitro are often fairly low.

 

Despite IVF being used routinely for over 40 years now, it’s not abundantly clear if, or how often, IVF may introduce genomic alternations or off-target affects in embryos. Likewise, scientists and clinicians are often unable to scrutinise changes produced through natural cellular processes including recombination and aging. So, it may be OK to do controlled experiments on using CRISPR to try and prevent multi-generational suffering. But, there has to be a long term investigation on the side effects of germline genome editing. Science has advanced a lot but still there are lot of things that are yet to be described or discovered by science. Trying to reduce human suffering should not give rise to new bigger sufferings and care must be taken not to create a Frankenstein.

 

References:

 

http://www.frontlinegenomics.com/news/29321/opinion-piece-morally-is-germline-genome-editing-all-that-different-to-ivf/

 

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