Εarly transcriptional effects of 17β-estradiol, 17β-estradiol-BSA and tamoxifen in human NSCLC cell lines A549 and H520

Assessment of different subcellular localizations (membrane, cytosol, nucleus) of estrogen receptors by multi-epitope protein expression in 200 NSCLC specimens and matched non-cancerous tissues and ESR-1 probe mapping meta-analysis of Affymetrix 2.0 plus data in 1398 NSCLC tumors and normal lung tissues and 39 NSCLC cell lines led us to the conclusion that ERα extranuclear variants are the main ERs in NSCLC. In order to further analyze these effects we treated A549 and H520 cell lines with 17β-estradiol, 17β-estradiol-BSA (plasma membrane impermeable conjugate) and tamoxifen for 3h, in order to investigate early transcriptional effects and responsiveness to estrogen agonists and antagonists. The aim of this study was to demonstrate the functionality of NSCLC ERs and decipher which genes, canonical pathways and networks are affected by each treatment. Two NSCLC cell lines (HTB-182 and A549) were studied. As extranuclear ERs are particularly prone to trigger early transcriptional effects, 17β-estradiol-BSA was used to detect signals originating exclusively from plasma membrane bound ERs, and compare them with the signals generated by 17β-estradiol (acting in both intracellular and membrane bound ERs). Tamoxifen, an endocrine disruptor that can trigger mainly antagonist effects was used as an inhibitor. Therefore cells were either exposed to vehicle (ethanol) or 17-β estradiol, 17-β estradiol plus tamoxifen, 17-β estradiol-BSA, 17-β estradiol-BSA plus tamoxifen,