Use of a small molecule inhibitor drug to treat human papillomavirus induced cancer

Human Papillomavirus (HPV) afflicts millions of individuals throughout the world and is the most prevalent sexually transmitted disease in the United States. Several strains of HPV have been linked to the formation of cancer, manifesting itself in a variety of locations (e.g; the vulva/vaginal, penis, anus, head and neck). Current cancer treatments have been limited to three established methods: chemotherapy, radiation and surgery. Each of these treatments have significant issues and provide mixed results for patients. Recent developments in the use of computer molecular modeling and advancements in the knowledge of cancer pathways have opened numerous new avenues for cancer treatment. A team led by Dr. Shaomeng Wang at the University of Michigan, Ann Arbor have used crystalline structure studies of the MDM2-p53 interaction to synthesize a molecule that has a higher affinity to MDM2 than p53, thus when the molecule is introduced into the cell it outcompetes p53 for MDM2 binding sites which frees p53. The freed p53 is then able to act as a tumor suppressor. The development of specific inhibitors as a potential cancer treatment has great promise for the battle against cancer. These small molecule inhibitors would have the potential to be a highly effective and specific treatment of cancer lacking many of the drawbacks of current cancer treatments. The goal of this grant proposal is to use the promising approach utilized by Dr. Wang's team to treat HPV induced cancer. The hypothesis of this proposed study is that a small molecule designed de novo using bioinformatics software will be able to bind to E7 protein derived from Human Papillomavirus, inhibiting E7 from binding to the cell cycle regulatory protein pRb, and thereby inhibiting cancerous growth caused by HPV. The specific aims of this study are to: I. Utilize structure data on the E7-pRb binding pocket to design small molecule inhibitor candidates using computer modeling software. II. Utilize a Competitive Fluorescence Binding Assay to identify candidate molecules with the ability to outcompete pRb for the E7 binding pocket. III. Utilize a Cell Permeability Assay to determine whether candidate molecules can enter cells. IV. Utilize HPV cell cultures to test the ability of the small molecule inhibitors to halt cancerogenesis in vitro. V. Evaluation of the effects of the small molecule inhibitors on HPV cells. The development of a small molecule inhibitor to block the binding of pRb and HPV protein E7 is a key step in the development of a successful non-invasive therapy for HPV induced cancer. The use of the AMBER software suite and performing the series of steps above to evaluate their effectiveness to prevent the E7-pRb complex and inhibiting cell proliferation will be a critical step towards developing a new drug to treat HPV-induced cancer.