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

Tag Archives: brain cancer

Friday Science Review: May 14, 2010

A Cure for Brain Cancer: An aggressive type of brain cancer called glioblastoma may be cured using the small molecule dichloracetate (DCA), a cheap and safe generic compound.  The drug works by altering the metabolism of the cancer cells, which is an emerging concept that exploits the different (higher) energy demand of cancer cells.  DCA’s target in the cells is the metabolic enzyme pyruvate dehydrogenase kinase II and it also promotes cell death in glioblastoma cancer cells and cancer stem cells.  In an 18-month study, some of the five patients’ tumours either regressed in size or did not grow any more.  Drs. Kenn Petruk and Evangelos Michelakis at the University of Alberta describe their study showing efficacy of DCA in humans for the first time in the journal Science Translational Medicine.  It is interesting to note that these and future studies are funded by government grants and private donations since the pharmaceutical industry is not interested in a compound that is readily available and without intellectual property protection (ie. no $cha-ching$).

Embryonic Cells Can Stop Viruses: Embryonic cells have a natural defence mechanism to limit the ability of viruses to express their genes and thereby prevent infection and further spread of the virus.  Researchers also determined that the different layers of cells in the developing embryo have different capacities to silence viral activation.  This “graphical abstract” published in Cell Stem Cell shows the outer layer of extraembryonic endoderm stem cells as the first line of defence with the strongest abilities to extinguish viral gene expression.  Several proteins including chromatin remodelling and repressor complex proteins were also identified to play key roles in this process.  The study was lead by Dr. Mellissa Mann at the University of Western Ontario.

If Only Mice Could Talk: This one is a bit strange.  It looks like mice express pain through facial expressions similar to the way humans do.  McGill University researchers developed the Mouse Grimace Scale to aid scientists working with lab animals to better ‘communicate’ with the animals.  Not only will this help to minimize and manage the stress that is inflicted on the animals but they can read the facial responses to determine whether a drug treatment is working or as an indicator of negative side effects.  Check out the study by Dr. Jeffrey Mogil in the issue of Nature Methods.

Pathogens Are Our Friends: Diphtheria Toxin (DT) is a potent cytotoxin that kills the cells that it binds to.  The DT385 is a recombinant version that is truncated and can be targeted to cancer cells to be used as a therapeutic agent.  In the present study, 15 of the18 human cancer lines tested were inhibited by DT385 as a result of increased apoptosis and decreased protein synthesis.  Dr. David Waisman at Dalhousie University published his study online in PLoS One.  Using pathogen proteins as therapeutic agents is not a new concept.  Oncolytics Biotech’s REOLYSIN® is derived from the Reovirus and Advaxis, Inc. exploits the Listeria bacterium to activate the immune system in an immunotherapy approach.

Studying Herpes Infection: Dr. Karen Mossman (McMaster University) investigated Herpes Simplex Virus-1 infection and how a viral protein, ICP0, is localized properly in the cell to block Interferon Regulatory Factor 3 (IRF3), the cell’s innate antiviral mechanism.  The study is described in PLoS One journal.

Friday Science Review: March 26, 2010

Why Did the Duck Kill the Chicken? Well… a scientific explanation is RIG-I.  Ducks are resistant to influenza viruses but may by asymptomatic carriers.  One of the reasons for ducks’ resistance is because ducks express the RIG-I protein that senses the presence of the viruses.  Chickens, however, do not appear to express RIG-I or a similar protein and have no method to detect the presence of viruses to illicit an immune response.  This could have implications to the poultry industry who do not want to see their entire farm wiped out by a viral outbreak and may want to start breeding transgenic chickens expressing RIG-I.  The discovery was led by Dr. Katharine Magor and her team at the University of Alberta and is published in the early edition of the Proceedings of the National Academy of Sciences.

Promoting Cancer Cell Growth: The YB-1 (Y-box binding protein-1) transcription factor is a known oncogene that is expressed in a significant percentage of breast cancers.  In this study, scientists demonstrated that YB-1 induces the expression of CD44 and CD49f, which are associated with cancer stem cells and used as stem cell markers.  Although they do not make a direct link to breast cancer stem cells, they suggest that it is this link that explains why YB-1 expressing cancers are resistant to drugs such as paclitaxel and are associated with disease recurrence and poor outcome.  The principal investigator of the study was Dr. Sandra Dunn at the University of British Columbia. Details of the study were reported in Cancer Research.

Knock, knock… Let Me In: A transporter protein that is selectively expressed in blood cells can be manipulated to facilitate the entry of cancer drugs into the cell.  This is extremely important for new treatment regimes against blood cancers such as AML and other leukemias.  Researchers found that the Human Carnitine Transporter encoded by the SLC22A16 gene acts as a gateway and can mediate the uptake of the polyamine class of drugs such as the anti-cancer agent Bleomycin.  Dr. Dindial Ramotar, Université de Montréal, first demonstrated this in yeast cells and now in human cells as reported in the Journal of Biological Chemistry.

Please, No More Radiation: A genetic mutation in the p53 gene in children with a rare type of brain cancer – choroid plexus carcinoma (CPC) – is a new marker indicating a poor response to radiation therapy.  It is unfortunate that this signals a more aggressive disease, however, this finding would relieve the patient of having to suffer through the difficulties of radiation.  The inherited p53 mutation is associated with a condition called Li-Fraumeni syndrome and is found in about 50% of CPC cases.  Without the mutation, CPC patients treated by radiation have a good chance of recovery.  The study, led by Dr. David Malkin at the Hospital for Sick Children, Toronto, is published in the advance online issue of the Journal of Clinical Oncology.

Mooooooooo: Scientists have finished sequencing the genome of two different types of cows – one beef and one dairy – using Life Technologies’ next generation SOLiD™ 3 System.  It cost $130K and took only seven months to complete.  In comparison, it cost $50M and four years, finishing in 2009, to sequence the first cow.  The genomic information is important to the industry for making breeding decisions and to identify genetic markers of specific desirable traits.  So that T-bone steak waiting for you to grill up this summer will be even juicier and tastier.  The Bovine Genomics Program at the University of Alberta led by Dr. Stephen Moore performed the sequencing study.

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Friday Science Review: March 13, 2009

Training Brains:  Sheena Josselyn’s lab at SickKids specifically erased a fear memory in mice by selectively ablating CREB neurons using an inducible diptheria toxin.  Let me break this down, because it’s so unbelievably cool: 

  • they trained mice to be afraid of a sound,
  • then they destroyed some specific cells in the brains of the mice,
  • then the mice forgot that they were afraid of the sound.

The mice were subsequently able to learn new things, like how to find cheese in a maze, and were even able to learn to be afraid of the same sound again.  Between this and the mind-reading experiment in the UK this week, it’s enough to give you a serious bout of insomnia … which often lasts over a year, according to researchers at Laval.

Gout Rout: Dr. Hyon Choi and colleagues at the University of British Columbia reported in Monday’s issue of the Archives of Internal Medicine, that Vitamin C appeared to lower the levels of uric acid in the blood, and that men who take in more vitamin C appear to be less likely to develop gout, a painful type of arthritis.

Beef Relief: Researchers using Bioniche’s E. coli O157 vaccine, Econiche™, published a study in Foodborne Pathogens and Disease showing that vaccinated cattle were 92% less likely to be colonized with E. coli O157:H7 than non-vaccinated cattle (odds ratio (OR)=0.07, p=0.0008). This is the second published study demonstrating more than 90% effectiveness of the Bioniche vaccine against colonization.

Anti-cancer Advancers:

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