Breast cancer is the leading female cancer in developed countries. While anti-estrogen based therapies are currently the frontline treatment for most mammary tumors, development of resistance to these treatments is a major clinical challenge that has not yet been adequately addressed. If patient prognosis is to improve, we need to investigate new pharmaceutical targets to address this problem.
We have previously demonstrated the pivotal role that local (or autocrine) production of human growth hormone (hGH) plays in oncogenic transformation and progression of mammary cell carcinoma, both in vitro and in vivo. Expression of growth factors or growth factor receptors by tumor cells has been proposed as one possible mechanism for developing resistance to anti-estrogen therapy. The current study aims to define the role of autocrine hGH in the development of resistance to anti-estrogen based treatment of mammary cell carcinomas. The potential clinical utility of hGH antagonism will be delineated by use of a Food and Drug Association-approved compound. This project will therefore define a novel therapeutic strategy, with potentially rapid clinical application, to improve the prognosis of patients with hormone sensitive breast cancer.