Sharks could help prevent human tooth loss.

Scientists have identified a network of genes that enables sharks to develop and regenerate teeth throughout their lifetime, a finding that may pave the way for new therapies to help humans with tooth loss. The genes also allow sharks to replace rows of their teeth using a conveyor belt-like system. Scientists have known that some fish, such as sharks and rays, develop rows of highly specialized teeth with the capacity for lifelong regeneration. However the genetic mechanisms which enable this to happen were poorly understood.Now a research team, led by Dr Gareth Fraser from the University of Sheffield in UK has identified how a special set of epithelial cells form, called the dental lamina, which are responsible for the lifelong continuation of tooth development and regeneration in sharks. Humans also possess this set of cells, which facilitate the production of replacement teeth, but only two sets are formed - baby and adult teeth - before this set of specialized cells is lost. The team shows that these tooth-making genes found in sharks are conserved through 450 million years of evolution, and probably made the first vertebrate teeth. These 'tooth' genes, therefore make all vertebrate teeth from sharks to mammals, however in mammals like humans, the tooth regeneration ability, that utilizes these genes, has been highly reduced over time. "We know that sharks are fearsome predators and one of the main reasons they are so successful at hunting prey is because of their rows of backward pointing, razor-sharp teeth that regenerate rapidly throughout their lifetime, and so are replaced before decay," said Fraser. "The Jaws films taught us that it is not always safe to go into the water, but this study shows that perhaps we need to in order to develop therapies that might help humans with tooth loss," Fraser said. Through analyzing the teeth of cat -shark embryos, the researchers characterized the expression of genes during stages of early shark tooth formation. They found that these genes participate in the initial emergence of shark's teeth and are re-deployed for further tooth regeneration. The study suggests that at the beginning of the sharks' evolutionary history, their teeth were most likely continuously regenerated and used a core set of genes from members of key developmental signalling pathways, which were instrumental in sharks evolving to maintain the ability to re-deploy the genes to replace teeth when needed. Story culled from business standard.

Sharks and secret cure to breast cancer in human

ACCORDING TO RECENT WORK, sharks are fingered in the cure of breast cancer.In Melbourne, Sept 27 (ANI): Researchers have claimed that a type of antibody found only in the blood of sharks could help tackle breast cancer. It is thought that the unique IgNAR antibodies could be used to prevent the growth of cancer cells and research into them could lead to the development of new drugs to fight one of the most common form of the disease, News.com.au reported. Biologists from the University of Aberdeen have been awarded 345,660 Australian dollars by Scottish cancer research charity the Association for International Cancer Research (AICR) to carry out a three-year study. Their work will focus on two molecules, HER2 and HER3, found on the surface of cancer cells which, when they pair-up, are responsible for signalling cancer cells to grow and divide. Potentially, IgNAR antibodies could be used to stop these molecules from working and sending the signal. Dr Helen Dooley who is from the university's School of Biological Sciences and will lead the study sais that IgNAR antibodies are interesting because they bind to targets, such as viruses or parasites, in a very different way to the antibodies found in humans. (ANI) ANIMAL HEALTH= HUMAN HEALTH.