17Beta-estradiol promotes aggressive laryngeal cancer through membrane-associated estrogen receptor-alpha 36.

ABSTRACT: 17?-estradiol (E2) plays a key role in tumorigenesis by enhancing cell survivability and metastasis through its cytoplasmic receptors. Recently, a variant of estrogen receptor alpha, ER?36 has been implicated as a substantial mediator of E2's proliferative and antiapoptotic effects through rapid membrane-associated signaling, and cancers previously regarded as hormone-independent due to the absence of traditional receptors, may in fact be susceptible to E2. Despite rising from a secondary sex organ and having a clear gender disposition, laryngeal cancer is not uniformly accepted as hormone dependent, even in the face of compelling evidence of E2 responsiveness. The aim of this study was to further elucidate the role of E2 in the tumorigenesis of laryngeal cancer, both in vitro and in vivo. ER?36 presence was evaluated in membranes of the laryngeal carcinoma cell line, Hep2, as well as in laryngeal tumor samples. In vitro ER?36 was found to mediate rapid activation of protein kinase C and phospholipase D by E2, leading to increased proliferation and protection against chemotherapy-induced apoptosis. Furthermore, in response to E2 activation of ER?36, an upregulation of angiogenic and metastatic factors was observed. Clinical analysis of laryngeal tumors revealed a similar association between the amount of ER?36 and VEGF and indicated a role in lymph node metastasis. These findings present compelling evidence of ER?36-dependent E2 signaling in laryngeal cancer. Thus, targeting ER?36 may reduce the deleterious effects of E2 in laryngeal cancer, ultimately suggesting the importance of antiestrogen therapy or the production of novel drugs that specifically target ER?36.

SUBMITTER: Schwartz N 

PROVIDER: S-EPMC3947116 | biostudies-literature | 2014 Feb

REPOSITORIES: biostudies-literature