Advertisements
Feeds:
Posts
Comments

Posts Tagged ‘UC Berkeley’


Larry H Bernstein, MD, Reporter

Leaders in Pharmaceutical Intelligence

Lasker~Koshland
Special Achievement Award in Medical Science

Award Description

Mary-Claire King
For bold, imaginative, and diverse contributions to medical science and human rights — she discovered the BRCA1 gene locus that causes hereditary breast cancer and deployed DNA strategies that reunite missing persons or their remains with their families.

The 2014 Lasker~Koshland Award for Special Achievement in Medical Science honors a scientist who has made bold, imaginative, and diverse contributions to medical science and human rights. Mary-Claire King(University of Washington, Seattle) discovered the BRCA1 gene locus that causes hereditary breast cancer and deployed DNA strategies that reunite missing persons or their remains with their families. Her work has touched families around the world.

As a statistics graduate student in the late 1960s, King took the late Curt Stern’s genetics course just for fun. The puzzles she encountered there—problems posed by Stern—enchanted her. She was delighted to learn that people could be paid to solve such problems, and that mathematics holds their key. She decided to study genetics and never looked back.

During her Ph.D. work with the late Allan Wilson (University of California, Berkeley), King discovered that the sequences of human and chimpanzee proteins are, on average, more than 99 percent identical; DNA sequences that do not code for proteins differ only a little more. The two primates therefore are much closer cousins than suggested by fossil studies of the time. The genetic resemblance seemed to contradict obvious distinctions: Human brains outsize those of chimps; their limbs dwarf ours; and modes of communication, food gathering, and other lifestyle features diverge dramatically. King and Wilson proposed that these contrasts arise not from disparities in DNA sequences that encode proteins, but from a small number of differences in DNA sequences that turn the protein-coding genes on and off.

Just as genetic changes drive species in new directions, they also can propel cells toward malignancy. From an evolutionary perspective, the topic of breast cancer began to intrigue King. The illness runs in families and is clearly inherited, yet many affected women have no close relatives with the disease. It is especially deadly for women whose mothers succumbed to it—and risk increases for those who have a mother or sister with breast cancer, particularly if the cancer struck bilaterally or before menopause. Unlike the situation with lung cancer, no environmental exposure distinguishes sisters who get breast cancer from those who remain disease free.

By studying a rare familial cancer, Alfred Knudsen (Lasker Clinical Medical Research Award, 1998) had shown in the early 1970’s how an inherited genetic defect could increase vulnerability to cancer. In the model he advanced, some families harbor a damaged version of a gene that normally encourages proper cellular behavior. Genetic mishaps occur during a person’s lifetime, and a second “hit” in a cell with the first physiological liability nudges the injured cell toward malignancy. A similar story might play out in families with a high incidence of breast cancer, King reasoned. She began to hunt for the theoretical pernicious gene in 1974.

2014_illustration_special
The hunt
Many geneticists doubted that susceptibility to breast cancer would map to a single gene; even if it did, finding the culprit seemed unlikely for numerous reasons. First, most cases are not familial and the disease is common—so common that inherited and non-inherited cases could occur in the same families. Furthermore, the malady might not strike all women who carry a high-risk gene, and different families might carry different high-risk genes. Prevailing views held that the ailment arises from the additive effects of multiple undefined genetic and environmental insults and from complicated interactions among them. No one had previously tacked such complexities, and an attempt to unearth a breast cancer gene seemed woefully naïve.

To test whether she could find evidence that particular genes increase the odds of getting breast cancer, King applied mathematical methods to data from more than 1500 families of women younger than 55 years old with newly diagnosed breast cancer. The analysis, published in 1988, suggested that four percent of the families carry a single gene that predisposes individuals to the illness.

The most convincing way to validate this idea was to track down the gene. Toward this end, King analyzed DNA from 329 participating relatives with 146 cases of invasive breast cancer. In many of the 23 families to which the participants belonged, the scourge struck young women, often in both breasts, and in some families, even men.

In late 1990, King (by then a professor at the University of California, Berkeley) hit her quarry. She had zeroed in on a suspicious section of chromosome 17 that carried particular genetic markers in women with breast cancer in the most severely affected families. Somewhere in that stretch of DNA lay the gene, which she named BRCA1.

This discovery spurred an international race to find the gene. Four years later, scientists at Myriad Genetics, Inc. isolated it. Alterations in either BRCA1 or a second breast-cancer susceptibility gene, BRCA2, found by Michael Stratton and colleagues (Institute of Cancer Research, UK) increase risk of ovarian as well as breast cancer. The proteins encoded by these genes help maintain cellular health by repairing marred DNA. When theBRCA1 or BRCA2 proteins fail to perform their jobs, genetic integrity is compromised, thus setting the stage for cancer.

About 12 percent of women in the general population get breast cancer at some point in their lives. In contrast, 65 percent of women who inherit an abnormal version of BRCA1 and about 45 percent of women who inherit an abnormal version of BRCA2 develop breast cancer by the time they are 70 years old. Individuals with troublesome forms of BRCA1 and BRCA2 can now be identified, monitored, counseled, and treated appropriately.

Harmful versions of other genes also predispose women to breast cancer, ovarian cancer, or both. Several years ago, King devised a scheme to screen for all of these genetic miscreants. This strategy allows genetic testing and risk determination for breast and ovarian cancer; it is already in clinical practice.

Genetic tools, human rights
King has applied her expertise to aid people who suffer from ills perpetrated by humans as well as genes. She helped find the “lost children” of Argentina—those who had been kidnapped as infants or born while their mothers were in prison during the military regime of the late 1970s and early 1980s. Some of these youngsters had been illegally adopted, many by military families. In 1983, King began identifying individuals, first with a technique that was originally designed to match potential organ transplant donors and recipients. She then developed an approach that relies on analysis of DNA from mitochondria—a cellular component that passes specifically from mother to child, and is powerful for connecting people to their female forebears. King helped prove genetic relationships and thus facilitated the reunion of more than 100 of the children with their families.

Later, the Argentinian government asked if she could help identify dead bodies of individuals thought to have been murdered. King harnessed the same method to figure out who had been buried in mass graves. She established that teeth, whose enamel coating protects DNA in the dental pulp from degradation, offer a valuable resource when attempting to trace remains in situations where long periods have elapsed since the time of death.

This and related approaches have been used to identify soldiers who went missing in action, including the remains of an American serviceman who was buried beneath the Tomb of the Unknowns in Arlington National Cemetery for 14 years, as well as victims of natural disasters and man-made tragedies such as 9/11.

Mary-Claire King has employed her intellect, dedication, and ethical sensibilities to generate knowledge that has catalyzed profound changes in health care, and she has applied her expertise to promote justice where nefarious governments have terrorized their citizens.

by Evelyn Strauss

Advertisements

Read Full Post »


Ribozymes and RNA Machines –  Work of Jennifer A. Doudna

Reporter: Aviva Lev-Ari, PhD, RN

 

UPDATED 3/27/2014

New DNA-editing technology spawns bold UC initiative

http://newscenter.berkeley.edu/2014/03/18/new-dna-editing-technology-spawns-bold-uc-initiative/

Crispr Goes Global

http://vcresearch.berkeley.edu/news/profile/doudna_jennifer

UPDATED 3/5/2014

Double Nicking by RNA-Guided CRISPR Cas9 for Enhanced Genome Editing Specificity

http://www.cell.com/retrieve/pii/S0092867413010155

One-Step Generation of Mice Carrying Mutations in Multiple Genes by CRISPR/Cas-Mediated Genome Engineering

http://www.cell.com/retrieve/pii/S0092867413004674

RNA-Guided Human Genome Engineering via Cas9

http://www.sciencemag.org/content/suppl/2013/01/03/science.1232033.DC1

SOURCE

From: Expert CRISPR/Cas9 Publications <Expert_CRISPRCas9_Publications@mail.vresp.com>
Date: Tue, 04 Mar 2014 17:03:01 +0000
To: <avivalev-ari@alum.berkeley.edu>
Subject: CRISPR-mediated gene editing resources

 

UPDATED on 11/10/2013

Exclusive: ‘Jaw-dropping’ breakthrough hailed as landmark in fight against hereditary diseases as Crispr technique heralds genetic revolution

Development to revolutionise study and treatment of a range of diseases from cancer, incurable viruses such as HIV to inherited genetic disorders such as sickle-cell anaemia and Huntington’s disease

SCIENCE EDITOR

Thursday 07 November 2013

A breakthrough in genetics – described as “jaw-dropping” by one Nobel scientist – has created intense excitement among DNA experts around the world who believe the discovery will transform their ability to edit the genomes of all living organisms, including humans.

Click image above to enlarge graphic

The development has been hailed as a milestone in medical science because it promises to revolutionise the study and treatment of a range of diseases, from cancer and incurable viruses to inherited genetic disorders such as sickle-cell anaemia and Down syndrome.

For the first time, scientists are able to engineer any part of the human genome with extreme precision using a revolutionary new technique called Crispr, which has been likened to editing the individual letters on any chosen page of an encyclopedia without creating spelling mistakes. The landmark development means it is now possible to make the most accurate and detailed alterations to any specific position on the DNA of the 23 pairs of human chromosomes without introducing unintended mutations or flaws, scientists said.

The technique is so accurate that scientists believe it will soon be used in gene-therapy trials on humans to treat incurable viruses such as HIV or currently untreatable genetic disorders such as Huntington’s disease. It might also be used controversially to correct gene defects in human IVF embryos, scientists said.

Until now, gene therapy has had largely to rely on highly inaccurate methods of editing the genome, often involving modified viruses that insert DNA at random into the genome – considered too risky for many patients.

The new method, however, transforms genetic engineering because it is simple and easy to edit any desired part of the DNA molecule, right down to the individual chemical building-blocks or nucleotides that make up the genetic alphabet, researchers said.

“Crispr is absolutely huge. It’s incredibly powerful and it has many applications, from agriculture to potential gene therapy in humans,” said Craig Mello of the University of Massachusetts Medical School, who shared the 2006 Nobel Prize for medicine for a previous genetic discovery called RNA interference.

“This is really a triumph of basic science and in many ways it’s better than RNA interference. It’s a tremendous breakthrough with huge implications for molecular genetics. It’s a real game-changer,” Professor Mello told The Independent.

“It’s one of those things that you have to see to believe. I read the scientific papers like everyone else but when I saw it working in my own lab, my jaw dropped. A total novice in my lab got it to work,” Professor Mello said.

In addition to engineering the genes of plants and animals, which could accelerate the development of GM crops and livestock, the Crispr technique dramatically “lowers the threshold” for carrying out “germline” gene therapy on human IVF embryos, Professor Mello added.

The new method of gene therapy makes it simple and easy to edit any desired part of the DNA molecule (Getty Creative)

The new method of gene therapy makes it simple and easy to edit any desired part of the DNA molecule (Getty Creative) Germline gene therapy on sperm, eggs or embryos to eliminate inherited diseases alters the DNA of all subsequent generations, but fears over its safety, and the prospect of so-called “designer babies”, has led to it being made illegal in Britain and many other countries.

The new gene-editing technique could address many of the safety concerns because it is so accurate. Some scientists now believe it is only a matter of time before IVF doctors suggest that it could be used to eliminate genetic diseases from affected families by changing an embryo’s DNA before implanting it into the womb.

“If this new technique succeeds in allowing perfectly targeted correction of abnormal genes, eliminating safety concerns, then the exciting prospect is that treatments could be developed and applied to the germline, ridding families and all their descendants of devastating inherited disorders,” said Dagan Wells, an IVF scientist at Oxford University.

“It would be difficult to argue against using it if it can be shown to be as safe, reliable and effective as it appears to be. Who would condemn a child to terrible suffering and perhaps an early death when a therapy exists, capable of repairing the problem?” Dr Wells said.

The Crispr process was first identified as a natural immune defence used by bacteria against invading viruses. Last year, however, scientists led by Jennifer Doudna at the University of California, Berkeley, published a seminal study showing that Crispr can be used to target any region of a genome with extreme precision with the aid of a DNA-cutting enzyme called CAS9.

Since then, several teams of scientists showed that the Crispr-CAS9 system used by Professor Doudna could be adapted to work on a range of life forms, from plants and nematode worms to fruit flies and laboratory mice.

Earlier this year, several teams of scientists demonstrated that it can also be used accurately to engineer the DNA of mouse embryos and even human stem cells grown in culture. Geneticists were astounded by how easy, accurate and effective it is at altering the genetic code of any life form – and they immediately realised the therapeutic potential for medicine.

“The efficiency and ease of use is completely unprecedented. I’m jumping out of my skin with excitement,” said George Church, a geneticist at Harvard University who led one of the teams that used Crispr to edit the human genome for the first time.

“The new technology should permit alterations of serious genetic disorders. This could be done, in principle, at any stage of development from sperm and egg cells and IVF embryos up to the irreversible stages of the disease,” Professor Church said.

David Adams, a DNA scientist at the Wellcome Trust Sanger Institute in Cambridge, said that the technique has the potential to transform the way scientists are able to manipulate the genes of all living organisms, especially patients with inherited diseases, cancer or lifelong HIV infection.

“This is the first time we’ve been able to edit the genome efficiently and precisely and at a scale that means individual patient mutations can be corrected,” Dr Adams said.

“There have been other technologies for editing the genome but they all leave a ‘scar’ behind or foreign DNA in the genome. This leaves no scars behind and you can change the individual nucleotides of DNA – the ‘letters’ of the genetic textbook – without any other unwanted changes,” he said.

Timeline: Landmarks in DNA science

Restriction enzymes: allowed scientists to cut the DNA molecule at or near a recognised genetic sequence. The enzymes work well in microbes but are more difficult to target in the more complex genomes of plants and animals. Their discovery in the 1970s opened the way for the age of genetic engineering, from GM crops to GM animals, and led to the 1978 Nobel Prize for medicine.

Polymerase chain reaction (PCR): a technique developed in 1983 by Kary Mullis (below, credit: Getty) in California allowed scientists to amplify the smallest amounts of DNA – down to a single molecule – to virtually unlimited quantities. It quickly became a standard technique, especially in forensic science, where it is used routinely in analysing the smallest tissue samples left at crime scenes. Many historical crimes have since been solved with the help of the PCR test. Mullis won the Nobel Prize for chemistry in 1993.

RNA interference: scientists working on the changing colour of petunia plants first noticed this phenomenon, which was later shown to involve RNA, a molecular cousin to DNA. In 1998, Craig Mello and Andrew Fire in the US demonstrated the phenomenon on nematode worms, showing that small strands of RNA could be used to turn down the activity of genes, rather like a dimmer switch. They shared the 2006 Nobel Prize for physiology or medicine for the discovery.

Zinc fingers: complex proteins called zinc fingers, first used on mice in 1994, can cut DNA at selected sites in the genome, with the help of enzymes. Another DNA-cutting technique called Talens can do something similar. But both are cumbersome to use and difficult to operate in practice – unlike the Crispr technique.

VIEW VIDEO

http://www.independent.co.uk/news/science/indyplus-video-crispr-technique-8925604.html

a video of how the Crispr system derived from bacteria works on human cells to correct genetic defects

SOURCE

http://www.independent.co.uk/news/science/exclusive-jawdropping-breakthrough-hailed-as-landmark-in-fight-against-hereditary-diseases-as-crispr-technique-heralds-genetic-revolution-8925295.html?goback=%2Egde_2106240_member_5804987154979381248#%21

Jennifer A. Doudna

Professor of Chemistry
Professor of Biochemistry & Molecular Biology

email: doudna@berkeley.edu
office: 708A Stanley Hall
phone: 510-643-0225
fax: 510-643-0008

lab: 731 Stanley Hall
lab phone: 510-643-0113
lab fax: 510-643-0080

Research Group URL
Recent Publications

Research Interests

Chemical Biology

Ribozymes and RNA Machines: RNA forms a variety of complex globular structures, some of which function like enzymes or form functional complexes with proteins. There are three major areas of focus in the lab: catalytic RNA, the function of RNA in the signal recognition particle and the mechanism of RNA-mediated internal initiation of protein synthesis. We are interested in understanding and comparing catalytic strategies used by RNA to those of protein enzymes, focusing on self-splicing introns and the self-cleaving RNA from hepatitis delta virus (HDV), a human pathogen. We are also investigating RNA-mediated initiation of protein synthesis, focusing on the internal ribosome entry site (IRES) RNA from Hepatitis C virus. Cryo-EM, x-ray crystallography and biochemical experiments are focused on understanding the structure and mechanism of the IRES and its amazing ability to hijack the mammalian ribosome and associated translation factors. A third area of focus in the lab is the signal recognition particle, which contains a highly conserved RNA required for targeting proteins for export out of cells. Each of these projects seeks to understand the molecular basis for RNA function, using a combination of structural, biophysical and biochemical approaches.

Biography

Medical School, 1989-1991; Post-doctoral fellow, University of Colorado, 1991-1994; Assistant/Associate professor, (1994-1998), Professor, (1999-2001), Yale University. Professor of Biochemistry & Molecular Biology, UC Berkeley, (2002-). Howard Hughes Medical Investigator 1997 to present. Packard Foundation Fellow Award, 1996; NSF Alan T. Waterman Award, 2000. Member, National Academy of Sciences, 2002. Member, American Academy of Arts and Sciences, 2003; American Association for the Advancement of Science Fellow Award, 2008; Member, Institute of Medicine of the National Academies, 2010.

READ MORE

Diagnosing Diseases & Gene Therapy: Precision Genome Editing and Cost-effective microRNA Profiling

https://pharmaceuticalintelligence.com/2013/03/28/diagnosing-diseases-gene-therapy-precision-genome-editing-and-cost-effective-microrna-profiling/

Read Full Post »