Friday Science Review: April 23, 2010
April 23, 2010
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Iron Man 2: Actually, this is about IRP2 – Iron Regulatory Protein 2. Ok, not quite as exciting as the superhero movie but it is interesting/unexpected that overexpression of IRP2 promotes cancer cell growth. In contrast, the very similar IRP1 protein suppresses tumour growth. The difference seems to lie within a 73 amino acid sequence in IRP2 that is required for its growth promoting properties. It is a long stretch to try to make any link between iron intake and cancer based on this preliminary study but it does warrant further research to understand the roles of IRP1 and IRP2. Dr. Kostas Pantopoulos (McGill University) published his study in PLoS One.
Not All Herpes are the Same: There are many different strains of herpes viruses, each with slightly different properties and responses to drugs. Human herpesvirus 6A and 6B (HHV-6A, HHV-6B) variants are prime examples of this. Classic anti-viral drugs based on type 1 Interferon (IFN) are effective against HHV-6A infected cells but not cells infected with HHV-6B. Dr. Louis Flamand’s group at Université Laval’s Centre de Recherche en Rhumatologie et Immunologie (CRRI) worked out some of the molecular details explaining this difference. They mapped a 41 amino acid region in the IE1 protein that is present only in the HHV-6B strain, which acts to block any further genetic responses to the IFN drugs. These small differences between herpes strains make it difficult to effectively treat infected patients but research such as this one are very important to identify how to better target each specific strain. The study is reported in this week’s issue of the Proceedings of the National Academy of Sciences.
Hippos are Your (Kidney’s) Friend: Polycystic Kidney Disease (PKD) is a common genetic disease affecting an estimated 12.5 million people worldwide and is the forth leading cause of kidney failure. Researchers are unraveling the key molecular players involved in PKD. In this study, Dr. Liliana Attisano’s team (University of Toronto) took a closer look at the Hippo pathway and identified a new function for the transcriptional activator, TAZ. TAZ modulates the beta-Catenin/Wnt signalling pathway, which is important in development and morphogenetic events. Mouse knockouts that do not express TAZ develop polycystic kidneys and demonstrate the role that these pathways play in kidney disease. This study is reported in the latest edition of Developmental Cell.
Ovarian Cancer Cells Avoid Death: Researchers studying ovarian cancer determined the mechanism by which ovarian cancer cells thrive. The sequence goes like this: ovarian cancer ascites triggers an adhesion protein called alphavbeta5 integrin; this activates FAK phosphorylation and correlates with Akt activation; the Akt pathway inhibits the molecular events leading to cell death or apoptosis. Thus, ovarian ascites confers protection against cell death. This study reveals some possible key target points for therapeutic intervention in the treatment of ovarian cancer. Dr. Alain Piche at the Université de Sherbrooke describes his work in the journal Oncogene.