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Archive for the ‘Metastasis Process’ Category


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

 

A mutated gene called RAS gives rise to a signalling protein Ral which is involved in tumour growth in the bladder. Many researchers tried and failed to target and stop this wayward gene. Signalling proteins such as Ral usually shift between active and inactive states.

 

So, researchers next tried to stop Ral to get into active state. In inacvtive state Ral exposes a pocket which gets closed when active. After five years, the researchers found a small molecule dubbed BQU57 that can wedge itself into the pocket to prevent Ral from closing and becoming active. Now, BQU57 has been licensed for further development.

 

Researchers have a growing genetic data on bladder cancer, some of which threaten to overturn the supposed causes of bladder cancer. Genetics has also allowed bladder cancer to be reclassified from two categories into five distinct subtypes, each with different characteristics and weak spots. All these advances bode well for drug development and for improved diagnosis and prognosis.

 

Among the groups studying the genetics of bladder cancer are two large international teams: Uromol (named for urology and molecular biology), which is based at Aarhus University Hospital in Denmark, and The Cancer Genome Atlas (TCGA), based at institutions in Texas and Boston. Each team tackled a different type of cancer, based on the traditional classification of whether or not a tumour has grown into the muscle wall of the bladder. Uromol worked on the more common, earlier form, non-muscle-invasive bladder cancer, whereas TCGA is looking at muscle-invasive bladder cancer, which has a lower survival rate.

 

The Uromol team sought to identify people whose non-invasive tumours might return after treatment, becoming invasive or even metastatic. Bladder cancer has a high risk of recurrence, so people whose non-invasive cancer has been treated need to be monitored for many years, undergoing cystoscopy every few months. They looked for predictive genetic footprints in the transcriptome of the cancer, which contains all of a cell’s RNA and can tell researchers which genes are turned on or off.

 

They found three subgroups with distinct basal and luminal features, as proposed by other groups, each with different clinical outcomes in early-stage bladder cancer. These features sort bladder cancer into genetic categories that can help predict whether the cancer will return. The researchers also identified mutations that are linked to tumour progression. Mutations in the so-called APOBEC genes, which code for enzymes that modify RNA or DNA molecules. This effect could lead to cancer and cause it to be aggressive.

 

The second major research group, TCGA, led by the National Cancer Institute and the National Human Genome Research Institute, that involves thousands of researchers across USA. The project has already mapped genomic changes in 33 cancer types, including breast, skin and lung cancers. The TCGA researchers, who study muscle-invasive bladder cancer, have looked at tumours that were already identified as fast-growing and invasive.

 

The work by Uromol, TCGA and other labs has provided a clearer view of the genetic landscape of early- and late-stage bladder cancer. There are five subtypes for the muscle-invasive form: luminal, luminal–papillary, luminal–infiltrated, basal–squamous, and neuronal, each of which is genetically distinct and might require different therapeutic approaches.

 

Bladder cancer has the third-highest mutation rate of any cancer, behind only lung cancer and melanoma. The TCGA team has confirmed Uromol research showing that most bladder-cancer mutations occur in the APOBEC genes. It is not yet clear why APOBEC mutations are so common in bladder cancer, but studies of the mutations have yielded one startling implication. The APOBEC enzyme causes mutations early during the development of bladder cancer, and independent of cigarette smoke or other known exposures.

 

The TCGA researchers found a subset of bladder-cancer patients, those with the greatest number of APOBEC mutations, had an extremely high five-year survival rate of about 75%. Other patients with fewer APOBEC mutations fared less well which is pretty surprising.

 

This detailed knowledge of bladder-cancer genetics may help to pinpoint the specific vulnerabilities of cancer cells in different people. Over the past decade, Broad Institute researchers have identified more than 760 genes that cancer needs to grow and survive. Their genetic map might take another ten years to finish, but it will list every genetic vulnerability that can be exploited. The goal of cancer precision medicine is to take the patient’s tumour and decode the genetics, so the clinician can make a decision based on that information.

 

References:

 

https://www.ncbi.nlm.nih.gov/pubmed/29117162

 

https://www.ncbi.nlm.nih.gov/pubmed/27321955

 

https://www.ncbi.nlm.nih.gov/pubmed/28583312

 

https://www.ncbi.nlm.nih.gov/pubmed/24476821

 

https://www.ncbi.nlm.nih.gov/pubmed/28988769

 

https://www.ncbi.nlm.nih.gov/pubmed/28753430

 

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Pioneers of Cancer Cell Therapy:  Turbocharging the Immune System to Battle Cancer Cells — Success in Hematological Cancers vs. Solid Tumors

Curator: Aviva Lev-Ari, PhD, RN

Chimeric Antigen Receptor T-Cell Therapy: Players in Basic & Translational Research and Biotech/Pharma

The companies are teamed with academic pioneers:

  • Novartis with University of Pennsylvania;
  • Kite Pharma with the National Cancer Institute; 
  • Juno Therapeutics with Sloan Kettering,
  • the Fred Hutchinson Cancer Research Center in Seattle and Seattle Children’s Hospital.

cancer33

IMAGE SOURCE: National Cancer Institute

 

 “CAR-T cell immunotherapy” –  genetically modified T cells that are engineered to target specific tumor antigens and/or genes that are involved in survival, proliferation, and the enhancement of effector functions have been under intense research.

 

CAR technology was originally reported by Zelig Eshhar in 1993.

https://www.weizmann.ac.il/immunology/sci/EshharPage.html

Prof. Zelig Eshhar, Ph.D., served as Chairman of the Department of Immunology at the Weizmann Institute. Prof. Eshhar has been Chair of Scientific Advisory Board at TxCell S.A. since April 2016. Prof. Eshhar has been a Member of Scientific Advisory Board at Kite Pharma, Inc. since August 8, 2013. Prof. Eshhar served as a Member of Scientific Advisory Board at Intellect Neurosciences, Inc. since April 2006.

Prof. Eshhar pioneered the CAR approach (or T-Body as he termed it) to redirect T cells to recognize, engage and kill patient’s tumor cells by engineering them with a construct that combines the anti-target specificity of an antibody with T cell activation domains. Prof. Eshhar serves on several editorial boards, including Cancer Gene Therapy, Human Gene Therapy, Gene Therapy, Expert Opinion on Therapeutics, European Journal of Immunology and the Journal of Gene Medicine. He was a Research Fellow in the Department of Pathology at Harvard Medical School and in the Department of Chemical Immunology at the Weizmann Institute in Israel. His achievements were recognized by several international awards, most recently the CAR Pioneering award by the ATTACK European Consortium. Prof. Eshhar obtained his B.Sc. in Biochemistry and Microbiology and his M.Sc. in Biochemistry from the Hebrew University, and his Ph.D. in the Department of Immunology from the Weizmann Institute of Science.

http://www.bloomberg.com/research/stocks/people/person.asp?personId=32720993&privcapId=32390485

 

Zelig Eshhar and Carl H. June honored for research on T cell engineering for cancer immunotherapy

New Rochelle, NY, November 11, 2014–Zelig Eshhar, PhD, The Weizmann Institute of Science and Sourasky Medical Center, and Carl H. June, MD, PhD, Perelman School of Medicine, University of Pennsylvania, are co-recipients of the Pioneer Award, recognized for lentiviral gene therapy clinical trials and for their leadership and contributions in engineering T-cells capable of targeting tumors with antibody-like specificity through the development of chimeric antigen receptors (CARs). Human Gene Therapy, a peer-reviewed journal from Mary Ann Liebert, Inc., publishers, is commemorating its 25th anniversary by bestowing this honor on the leading Pioneers in the field of cell and gene therapy selected by a blue ribbon panel* and publishing a Pioneer Perspective by the award recipients. The Perspectives by Dr. Eshhar and Dr. June are available free on the Human Gene Therapy website at http://www.liebertpub.com/hgt until December 11, 2014.

In his Pioneer Perspective entitled “From the Mouse Cage to Human Therapy: A Personal Perspective of the Emergence of T-bodies/Chimeric Antigen Receptor T Cells” Professor Eshhar chronicles his team’s groundbreaking contributions to the development of the CAR T-cell immunotherapeutic approach to treating cancer. He describes the method’s conceptual development including initial proof-of-concept, and the years of experimentation in mouse models of cancer. They first tested the CAR T-cells on tumors transplanted into mice then progressed to spontaneously developing cancers in immune-competent mice, which Dr. Eshhar describes as “a more suitable model that faithfully mimics cancer patients.” He recounts successful antitumor effects in mice with CAR modified T-cells injected directly into tumors, with effects seen at the injection site and at sites of metastasis, and even the potential of the CAR T-cells to prevent tumor development.

Dr. Carl H. June has led one of the clinical groups that has taken the CAR therapeutic strategy from the laboratory to the patients’ bedside, pioneering the use of CD19-specific CAR T-cells to treat patients with leukemia. In his Pioneer Perspective, “Toward Synthetic Biology with Engineered T Cells: A Long Journey Just Begun” Dr. June looks back on his long, multi-faceted career and describes how he combined his knowledge and research on immunology, cancer, and HIV to develop successful T-cell based immunotherapies. Among the lessons Dr. June has embraced throughout his career are to follow one’s passions. He also says that “accidents can be good: embrace the unexpected results and follow up on these as they are often times more scientifically interesting than predictable responses from less imaginative experiments.”

“These two extraordinary scientists made seminal contributions at key steps of the journey from bench to bedside for CAR T-cells,” says James M. Wilson, MD, PhD, Editor-in-Chief of Human Gene Therapy, and Director of the Gene Therapy Program, Department of Pathology and Laboratory Medicine, University of Pennsylvania Perelman School of Medicine, Philadelphia.

SOURCE

http://www.eurekalert.org/pub_releases/2014-11/mali-ze111114.php

The General procedure of CAR-T cell therapy involves the follwoing steps:

1) Separate T cells from patient;

2) Engineer these T cells to express an artificial receptor, which is called “CAR” that usually targets tumor-specific antigen;

3) Expand the CAR T cells to a sufficient amount;

4) Re-introduce the CAR T cells to patient.

There are two major components that are critical to the CAR-T cell immunotherapy:

  • the design of CAR itself and
  • the choice of the targeted tumor specific antigen.

SOURCE

http://www.ochis.org/node/209

 

First publication on Adoptive transfer of genetically modified T cells is an attractive approach for generating antitumor immune responses

Eradication of B-lineage cells and regression of lymphoma in a patient treated with autologous T cells genetically engineered to recognize CD19

James N. Kochenderfer, Wyndham H. Wilson, John E. Janik, Mark E. Dudley, Maryalice Stetler-Stevenson, Steven A. Feldman, Irina Maric, Mark Raffeld, Debbie-Ann N. Nathan, Brock J. Lanier, Richard A. Morgan, Steven A. Rosenberg

Abstract

Adoptive transfer of genetically modified T cells is an attractive approach for generating antitumor immune responses. We treated a patient with advanced follicular lymphoma by administering a preparative chemotherapy regimen followed by autologous T cells genetically engineered to express a chimeric antigen receptor (CAR) that recognized the B-cell antigen CD19. The patient’s lymphoma underwent a dramatic regression, and B-cell precursors were selectively eliminated from the patient’s bone marrow after infusion of anti–CD19-CAR-transduced T cells. Blood B cells were absent for at least 39 weeks after anti–CD19-CAR-transduced T-cell infusion despite prompt recovery of other blood cell counts. Consistent with eradication of B-lineage cells, serum immunoglobulins decreased to very low levels after treatment. The prolonged and selective elimination of B-lineage cells could not be attributed to the chemotherapy that the patient received and indicated antigen-specific eradication of B-lineage cells. Adoptive transfer of anti–CD19-CAR-expressing T cells is a promising new approach for treating B-cell malignancies. This study is registered at www.clinicaltrials.gov as #NCT00924326.

SOURCE

According to Setting the Body’s ‘Serial Killers’ Loose on Cancer

After a long, intense pursuit, researchers are close to bringing to market a daring new treatment: cell therapy that turbocharges the immune system to fight cancer.

By ANDREW POLLACK  AUG. 1, 2016

http://www.nytimes.com/2016/08/02/health/cancer-cell-therapy-immune-system.html?_r=0

Dr. June’s 2011 publications did not cite Dr. Rosenberg’s paper [Blood, 2010] from the previous year, prompting Dr. Rosenberg to write a letter to The New England Journal of Medicine. Dr. June’s publications also did not acknowledge that the genetic construct he had used was the one he had obtained from Dr. Campana of St. Jude.

From the Lab to the bedside to the Out Patient Clinic

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Astrogliosis and Neuroinflammation: The Metastesis Process form Skin Melanoma to Brain Tumors

 

Reporter: Aviva Lev-Ari, PhD, RN
Cancer Res. 2016 Aug 1;76(15):4359-71. doi: 10.1158/0008-5472.CAN-16-0485. Epub 2016 Jun 3.

Incipient Melanoma Brain Metastases Instigate Astrogliosis and Neuroinflammation.

Abstract

Malignant melanoma is the deadliest of skin cancers. Melanoma frequently metastasizes to the brain, resulting in dismal survival. Nevertheless, mechanisms that govern early metastatic growth and the interactions of disseminated metastatic cells with the brain microenvironment are largely unknown. To study the hallmarks of brain metastatic niche formation, we established a transplantable model of spontaneous melanoma brain metastasis in immunocompetent mice and developed molecular tools for quantitative detection of brain micrometastases. Here we demonstrate that micrometastases are associated with instigation of astrogliosis, neuroinflammation, and hyperpermeability of the blood-brain barrier. Furthermore, we show a functional role for astrocytes in facilitating initial growth of melanoma cells. Our findings suggest that astrogliosis, physiologically instigated as a brain tissue damage response, is hijacked by tumor cells to support metastatic growth. Studying spontaneous melanoma brain metastasis in a clinically relevant setting is the key to developing therapeutic approaches that may prevent brain metastatic relapse. Cancer Res; 76(15); 4359-71. ©2016 AACR.

©2016 American Association for Cancer Research.

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