FUSOGENIC MEMBRANE PROTEINS AS THERAPEUTIC TRANSGENES

Measles virus exerts its cytopathic effect by cell-cell fusion which eventually leads to cell death. We have cloned the cDNA for the measles F and H fusogenic membrane glycoproteins into eukaryotic expression vectors and have shown significant cytotoxicity through induction of cell-cell fusion in different human tumor cell lines including A431 (epithelial carcinoma), C170 (colon cancer), HeLa (cervical cancer), TE671 (rhabdomyosarcoma), and the glioma cell lines U87 and U118. In addition, we have shown significantly higher bystander effects as compared to the herpes simplex thymidine kinase (HSV-tk) system. This proposal utilizes the fusogenic membrane proteins F and H of the measles virus to develop a clinician investigator's career in gene transfer/gene therapy. The applicant proposes to: 1) Investigate the use of fusogenic measles virus proteins F and H as novel therapeutic transgenes using the U87 and U118 glioma models. Gliomas were selected because they are highly lethal tumors despite the therapeutic use of surgery, radiation therapy, and chemotherapy. They also offer the further advantage of their limited metastatic potential that makes them appropriate targets for intratumoral gene transfer/gene therapy. We plan to a) construct retroviral vectors encoding the F and H transgenes, b) compare the developed vectors with the gold standard of cytotoxicity which is HSV-tk producing retroviral vectors in both glioma cell lines and tumor xenografts, and c) target vectors to the tumor environment by exploiting the over-expression of matrix metalloproteinases in gliomas. The long-term goal is to introduce this novel transgene system into clinical trials as a new therapeutic alternative. 2) Develop expertise to pursue an independent clinician scientist career within the area of gene transfer/gene therapy. In addition to the interaction with the mentor and co-mentors, this will be achieved through attending Mayo Graduate School courses and major scientific meetings, such as the American Association for Cancer Research and the American Society of Gene Therapy meetings.