Effect of HSP27 on Human Breast Tumor Cell Growth and Motility

摘要

This award is a Predoctoral Fellowship to support the doctoral training of Donna Egender. The goal of this research was to investigate the effects of the small stress protein, HSP27, on growth and motility characteristics of normal and tumor-derived human mammary cell lines. We hypothesized that cells overexpressing HSP27 would show increased motility, altered chemotactic properties, increased resistance to heat killing and to certain drugs. Donna has prepared and studied 19 clonal MDA23 1 breast tumor cell lines that overexpress human HSP27, and determined that, while heat resistance is increased in these cells, there is no consistent effect on their proliferation rates, drug resistance, motility or invasiveness. It is probable that the conflicting reports on the effect of increased HSP27 levels on mammary cells reflects clonal variation among the cell lines used. An additional study on hsp27 gene regulation in mammary cells following estrogen administration suggests that the ensuing increased HSP27 mRNA levels do not reflect a direct response to estrogen acting through the estrogen receptor on the hsp27 promoter sequences. Donna's Dissertation Committee has requested replication of specific experiments, but agree that she may begin writing. She should defend her thesis in December.