Question

• What is the role of RAS and HIF in angiogenesis

Answer 1

Ras family protein is involve in cell growth, differentiation and proliferation. Antigenesis is the process of formation of new blood vessels from pre vessels. Continuous need of oxygen and nutrients for tumor cells results in angiogenesis in tumor. H-ras, K-ras and N-ras are major protein of Ras family. Over expression of Ras oncogenes in tumor cells leas to tumor proliferation and tumor associated angiogenesis. Normal expression of Ras protein is helpful in antigenesis during hypoxia (lack of oxygen). additionally, it will help in cell adhesion, cell proliferation, cell migration and apoptosis.

    HIF is transcriptional factor (hypoxia inducible factor), which helps during hypoxia. In the low oxygen level (hypoxia), it up regulates some other genes like VEGF-A (vascular epithelial growth factor-A) which promotes angiogenesis in low oxygen level. Over expression of HIF in tumor will helps to spread tumors through cell proliferation by angiogenesis.