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Biotechnology, Health and Business in Canada, the United States and Worldwide

Tag Archives: Natural Killer Cells

Friday Science Review: February 26, 2010

A few medical research applications this week…

Personalized Medicine – for Lung Cancer: To develop a personalized medicine approach to treating non-small cell lung cancer (NSCLC), researchers generated a xenograft model where they implant human tumour tissue into the renal capsule of a host mouse.  As the tumour establishes itself, the mouse then becomes the platform for testing various chemotherapy regimes (cisplatin+vinorelbine; cisplatin+docetaxel; cisplatin+gemcitabine) to determine which one or combination therapy is the most effective against each of the different tumours.  They compared the results of the treatments in mice to retrospective patient outcomes and found significant correlation to consider the xenograft model a success.  Although it takes about 6-8 weeks for the results, they believe that it is quick enough to gain an insightful preliminary assessment of the potential therapeutic outcome.  Dr. Yuzhuo Wang led his team at the BC Cancer Agency and reports their work in Clinical Cancer Research.

HIV-1 Molecular Manipulations: HIV-1 infected patients exhibit a loss of CD4+ T cells, which are essential players in the defense against viral infections.  A new study reveals how the HIV-1 protein, Vpr, activates the Natural Killer (NK) cells by inducing the expression of stress-related proteins at the cell surface of CD4+ T cells.  The NK cells recognize the stress signals on CD4+ T cells and attacks and destroy these cells, leaving the patient with severely reduced CD4+ T cells.  Researchers also noticed that the continuous activation of NK cells eventually desensitizes them and they eventually lose their ability to perform their normal duties in attacking infected cells.  The molecular mechanisms of Vpr discovered in this study should help in future research leading to new therapeutic strategies.  Dr. Éric Cohen and his team at the Institut de recherches cliniques de Montréal describe their research in last week’s issue of Blood.

Protecting Your Heart: The blood pressure cuff you see in every doctor’s office can be used to limit the severity of heart attacks by triggering a molecular response in the body that protects the heart during an attack.  It is called remote ischemic preconditioning where the blood pressure cuff is used to intermittently cut off blood flow to the arm during an attack.  This triggers an innate response warning message throughout the body to release molecules to protect itself from the lack of blood flow.  In this particular study, the size of the heart attacks were reduced by 30-50% compared to control groups.  It is one of the most effective treatments and is relatively simple to administer.  Dr. Andrew Redington at The Hospital for Sick Children led the international study and is published in the The Lancet.

Friday Science Review: August 28, 2009

A Montreal flavour this week…

Critical link between EGFR and Src oncogenes: On the heels of last week’s Friday Science Review post on Stat3 in breast cancer, Dr. William Muller’s research team at McGill University has published another significant find linking well known oncogenes, Src and EGFR/ErbB2.  Among their results, they demonstrated how Src can interact with some mutant EGFR receptors (identified in lung cancers) but not with wild type EGFR.  When a Src inhibitor was applied to cells expressing mutant EGFR, it attenuated the cancer-inducing potential of these EGFR mutants.  This suggests that Src is an important enzyme in the EGFR mutant signaling pathway and may present an alternate pathway to combat cancer cell resistance to EGFR inhibitors.

Details of this study are described in this week’s Molecular and Cellular Biology.

MET oncogene in breast cancer: Next door to the Muller Lab at the new Goodman Cancer Centre in Montreal is Dr. Morag Park and her research team who recently generated a mouse model to mimic and study the Met oncogene in breast cancer.  The results were a complex cancer phenotype where gene expression and histological profiles demonstrated similarities to aggressive human breast cancers expressing Met.  Whereas prior to their study, Met was only correlated with poor outcome in breast cancer patients, this mouse model provides the specific link and identifies clinical cases where anti-Met therapy may be beneficial.

You can read more about it here in Proceedings of the National Academy of Sciences.

Key proteins in Natural Killer Cells: Also this week, Dr. André Veillette’s lab at the Institut de recherches cliniques de Montréal (IRCM) generated new insight into how Natural Killer Cells combat cancers of the blood, such as leukemias and lymphomas, or virus-infected blood cells.  As part of our immune system, the defense function of Natural Killer Cells requires three small proteins named SAP, EAT-2 and ERT that are unique to immune cells.  The proteins relay information from the cell surface SLAM family receptors to direct immune activities.  These data may eventually lead to pharmacological methods to increase the activity of Natural Killer Cells in destroying blood cancer cells or virus-infected cells.

Veillette’s lab generated knock-out mice missing all three proteins, which led to their findings, which are published in the latest edition of Nature Immunology.

p53 is regulated by JNK: p53 is a tumor suppressor protein that plays an important role in regulating cell growth and survival.  Its critical functions in the cell require p53 to be highly regulated through multiple layers of control, both to turn on and to turn off the protein’s activities.  One such method recently described in Proceedings of the National Academy of Sciences is through phosphorylation by the enzyme JNK.  This phosphorylation protects p53 from being targeted for destruction, thereby allowing p53 complexes to form and continue with their gene activating activities.

This research project was a collaboration between the Burnam Institute in San Diego and Dr. Katherine Borden’s team at the Université de Montréal.

Jurassic Park (for real?): Can you convert a chicken embryo to develop into a dinosaur?  No, this is not the makings of a movie but the idea of paleontologist Hans Larsson of McGill University who is proposing to try to make it work.  The theory is that by manipulating or swapping certain “switch” genes during the chicken embryo’s development, he can reproduce some features of a dinosaur.  He does not actually intend to hatch live prehistoric animals – for obvious reasons:

“It’s a demonstration of evolution,” said Larsson, who has studied bird evolution for the last 10 years.

“If I can demonstrate clearly that the potential for dinosaur anatomical development exists in birds, then it again proves that birds are direct descendants of dinosaurs.”

“We’re not going to hatch a T. rex or something,” Larsson chuckles.

The idea came to him after meeting Jack Horner, author of the book “How to Build A Dinosaur” and the technical advisor behind the Hollywood version of Jurassic Park.

Come back to the Friday Science Review (perhaps in a few years) for an update on the “chickensaurus” experiment…

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