Project Description: |
We have cloned a novel, endothelium specific protein, VACM-1, which shares sequence homology with cullins, a family of intracellular proteins that regulate diverse cellular functions. Our work indicates that VACM-1 protein regulates cellular growth by a mechanism that distinguishes it from growth regulating factors, and from other cullins, and thus suggests a unique biological role for this largely uncharacterized cul gene product. In cancer cell line and in endothelial cells VACM-1 inhibits growth while expression of VACM-1 mutant has a dominant negative effect on cellular proliferation in vitro as it increases cellular growth, and, importantly, converts endothelial cells to the angiogenic phenotype. Consequently, VACM-1 may play a role as a potential novel suppressor of angiogenesis in vivo. Thus, the goal of our research is to test the hypothesis that VACM-1 is involved in the regulation of endothelial cell growth, and to identify the mechanism of VACM-1 regulated angiogenesis in vitro. Specifically, we are studying pathways regulated by VACM-1, proteins that interact with VACM-1, and proteins that are regulated by VACM-1 expression. In our studies, we use of immunocytochemistry to elucidate the cellular changes induced by VACM-1 dominant negative phenotype in endothelial cells. Similarly, immunocytochemistry is used when examining the effects of siRNA to confirm that the angiogenic phenotype induced by VACM-1 mutant is indeed VACM-1-specific. These studies will provide us with a better understanding of the structure-function relationship of VACM-1 at the molecular and physiological level of VACM-1 dependent regulation of the endothelial cell growth, and, they will help to elucidate the mechanism(s) of angiogenesis and tumorigenesis. Consequently, these results may lead to development of strategies for diagnosis and intervention in the pathologies of excessive vascularization and in cellular growth, in general. Finally, these discoveries may lead to a better diagnosis and treatment of cancer. Students will be involved in designing experiments that test different aspects of the functional relationships between VACM-1 and cellular growth under different extracellular environmental conditions. Students will learn experimental procedures that include cell culture, immunocytochemistry, spectrophotometry, fluorescence polarization techniques, polyacrylamide gel analysis and Western blotting. Importantly, students will learn to read, discuss, and question research papers effectively. They are also expected to write a report/manuscript at the end of the semester/summer. |
