Jun Yang
St Jude Children’s Research Hospital, Memphis, USA
Title: Hypoxia, epigenetics and estrogen receptor in breast cancer
Biography
Biography: Jun Yang
Abstract
More than 1.7 million new cases of breast cancer occur every year, 70% of which are estrogen receptor alpha (ERα) positive. Anti-estrogen therapy to block ERα function is the most important approach in treatment of ERα positive patients. However, resistance eventually will develop for various reasons. Previous clinical studies suggest that the in vivo tumor environment may play a role in tamoxifen resistance, as hypoxia-inducible factor 1 alpha (HIF-1α) protein expression was associated with tamoxifen resistance in neoadjuvant, primary therapy of ERα-positive breast cancers as well as resistance to chemoendocrine therapy. However, whether HIF-1α plays an autonomous role in modulating endocrine therapy efficacy such as tamoxifen resistance is unknown. It is also puzzling why increased HIF-1α is associated with ERα positivity in clinical samples, since ERα negative breast cancer is more hypoxic. And how these two important oncogenic transcriptional factors interact has not yet been defined. In this presentation, I will discuss a new signaling pathway between ERα and HIF-1α, providing evidence that HIF-1α may account for anti-hormone therapy. I will also discuss how HIF-1α and ERα cooperate to drive expression of histone demethylase KDM4B in breast cancer, and demonstrate KDM4B as a potential therapeutic target.