Student: Betsy Gekonge '01

Supervisor: Stephen M. Festin, Assistant Professor of Biology

Project title: The evaluation Tamxoifen and AFP 8-mer treatments on ligand-activated estrogen receptor-mediated transcription by in MCF-7 cells.

Project Summary: During the duration of my summer internship we were working with MCF-7 cells, which are derived from human breast tumors. MCF-7 cells actively produce the estrogen receptor, an intranuclear hormone binding protein that activates the transcription of target genes when bound to estrogen. Tamoxifen is an antiestrogen that competes with estrogen for the binding site on the estrogen receptor. When MCF-7 cells are exposed to both tamoxifen and estrogen, tamoxifen binds with much higher affinity to the receptor and prevents the activation of transcription. Alpha-fetoprotein is a serum glycoprotein produced by the developing fetus that has been shown to behave as an antiestrogen in MCF-7 cells. The main aim of our project was to determine whether or not Alpha-fetoprotein and Tamoxifen co-operate when MCF-7 cells are exposed to both antiestrogenic agents. Overall, we were able to evaluate the potency of Estrogen stimulation, and determine the inhibition of this stimulation by doing dose response experiments with Tamoxifen. The data collected, enabled us to determine the ÔidealÕ inhibition concentration. Previous research had shown that AFP 8-mer inhibited the activation of transcription in MCF-7 cells. Based on this observation, we had hoped to evaluate the effect of both Tamoxifen and AFP 8-mer. Unfortunately, due to time constraints, we were not able to progress that far. However, this goal remains one of the future aims of this laboratory. Stipend support for B.G.. was provided by the Bristol-Myers Squibb Corporation