Estrogen regulation of apoptosis- how can one hormone stimulate and inhibit?

The link between oestrogen and the step and proliferation of breast cancer is well documented. Estrogen stimulates evolvement and inhibits apoptosis through estrogen receptor-mediated mechanisms in frequent cell types. Interestingly, there is strong evidence that estrogen induces apoptosis in breast cancer and other cell types. Fourty age ago, before the development of tamoxifen, high-dose estrogen was used to induce tumour regression of hormone-dependent breast cancer in post-menopausal women. While the mechanisms by which estrogen induces apoptosis were not completely known, virgin evidence from our laboratory and others demonstrates the involvement of the extrinsic (Fas/FasL) and the intrinsic (mitochondria) pathways in this process. We discuss the disparate apoptotic signaling pathways involved in E2 (17β-estradiol)-induced apoptosis, including the intrinsic and extrinsic apoptosis pathways, the NF-κB (nuclear factor-kappa-B)-mediated survival pathway as fine as the PI3K (phosphoinositide 3-kinase)/Akt signaling pathway. Breast cancer cells can very be sensitized to estrogen-induced apoptosis through suppression of glutathione by BSO (L-buthionine sulfoximine). This finding has implications for the authority of breast cancer with low-dose estrogen and other targeted therapeutic drugs.

Keywords: