Ramon Parsons, MD, PhD

We are focusing our efforts on the pathogenesis of breast and brain cancer. Our aim is to identify the genetic changes that lead a normal cell to develop into an advanced tumor. The genes targeted by these changes will then be analyzed to determine their normal function. We have recently identified a tumor suppressor gene, PTEN, that is mutated in breast, brain, prostate, and endometrial cancer. Our present goals are to (1) study the normal function of the PTEN gene, and (2) identify tumor suspressor genes that are lost in breast and/or brain tumor development.

Selected Publications:

• Li, J., Yen, C., Liaw, D., Podsypanina, K., Bose, S., Wang, S., Puc, Janusz, Miliaresis, C., Rodgers, L., McCombie, R., Bigner, S, H., Giovanella, B.P., Ittmann, M., Tycko, B., Hibshoosh, H., Wigler, M.H., and Parsons, R. PTEN, a putative protein tyrosine phosphatase gene mutated in human brain, breast, and prostate cancer. Science 275: 1943-1947 (1997).

• Liaw, D., Marsh, D.J., Li, J., Dahia, P.L.M., Wang, S.I., Zheng, Z., Bose, S., Call, K.M., Tsou, H.C., Peacocke, M., Eng, C., and Parsons, R. Germline mutations of the PTEN gene in Cowden disease, an inherited breast and thyroid cancer syndrome. Nature Genetics. 16: 64-67 (1997).

• Marsh, D.J., Dahia, P.L.M., Zheng, Z., Liaw, D., Parsons, R., Gorlin, R.J., and Eng, C. Germline mutations in the Cowden disease gene, PTEN, are present in Bannayan-Zonana syndrome. Nature Genetics. 16: 333-334 (1997).

• Tashiro, H., Blazes, M., Wu, R., Cho, K., Bose, S., Wang, S.I., Li, J., Parsons, R., and Hedrick Ellenson, L. Mutations in PTEN are frequent in endometrial carcinoma, but rare in other common gynecological malignancies. Cancer Research 57: 3935-3940 (1997).

• Myers, M.P., Stolarov, J.P., Eng, C., Li, J., Wang, S.I., Wigler, M.H., Parsons, R., and, Tonks, N.K. 1997. P-TEN, the tumor suppressor from chromosome 10q23, is a dual specificity phosphatase. Proc. Natl. Acad. Sci. (USA). 94: 9052-9057.

• Wang, S.I., Puc, J., Bruce, J.N., Cairns, P., Sidransky, D., and Parsons, R. Somatic mutations of PTEN in glioblastoma multiforme. Cancer Res. 57: 4183-4186 (1997).

• Bose, S., Wang, S.I., Terry, M.B., Hibshoosh, H., and Parsons, R. Allelic loss of chromosome 10q23 is associated with tumor progression in breast carcinoma. Oncogene 17: 123-127 (1998).

• Tamura, M., Gu, J., Matsumoto, K., Aota, S., Parsons, R., Yamada, K.M. Inhibition of cell migration, spreading, and focal adhesions by tumor suppressor PTEN. Science 280: 1614-1680 (1998).