Uncategorized Monday, 2015/10/19
A recent study has found new mechanism of pRb-a well know tumor suppressor. The research completed by scientists at University of Illinois in the United States and Spain Pompeu Fabra University, was published in International academic journals Gene & Development. Tumor suppressor is a kind of protein that acts as natural “brake” for cellular proliferation, having the ability to prevent the formation of malignant tumors. Depth understanding of how these proteins play a protective role may be the key factor for the development of targeted cancer therapies. Rb is a tumor inhibitory factor with long history of research, which was first found in children with retinoblastoma. And this is also how its name came into being. At the same time, it is also the first found tumor suppressor gene in humans and the first knockout anti-cancer gene on mice models. PRb protein encoded by this gene is a key regulatory factor that influence the cell growth, proliferation, differentiation, cell interactions and the occurrence of timely cell death process. At present, most of pRb studies are focusing on its impact on cell growth and division process. In this latest study, the researchers found that pRb can also inhibit tumorigenesis by limiting the activity of the molecule called KDM5A, an epigenetic modification enzymes that can regulate the expression of specific genes thereby affecting the energy consumption role of mitochondria within cells. And many cancer cells rely on glycolysis for energy, reducing the dependence of mitochondria. If the cancer cells are less differentiated or still in the immature state, then the tumor it formed would be more aggressive. The researchers found that resuming oxidation of mitochondria in cells that lack pRb can make the immature cancer cells become more mature and their division ability would also be reduced. Researchers inhibited the activity of KDM5A in several different pRb human cancer cells lines that have pRb deleted, and they found that each cell was transformed into normal metabolic processes and stopped division. They saw the same phenomenon in cells that produce excessive mitochondria. This study suggests that tumors may be particularly sensitive to metabolic therapy. It may be used in combination with conventional chemotherapy to treat cancer in the future.