Introduction. Epidermal growth factor receptor (EGFR) mutations are known as oncogene driver mutations and with EGFR\nmutations exhibit good response to the EGFR tyrosine kinase inhibitor Gefitinib. Some studies have shown that activation of\nestrogen and estrogen receptor ???? or ???? (ER????/????) promote adenocarcinoma.We evaluated the relationship between the two receptors\nand the potential therapeutic benefit with Gefitinib and Tamoxifen. Methods.We assessed the association between EGFRmutations\nas well as ER????/???? expression/location and overall survival in a cohort of 55 patients with LAC from a single hospital. PC9 (EGFR\nexon 19 deletion mutant; Gefitinib-vulnerable cells) and A549 (EGFR wild type; Gefitinib-resistant cells) cancer cells were used\nto evaluate the in vitro therapeutic benefits of combining Gefitinib and Tamoxifen. Results. We found that the cytosolic but not\nthe nuclear expression of ER???? was associated with better OS in LAC tumors but not associated with EGFRmutation. The in vitro\nstudy showed that combined Gefitinib and Tamoxifen resulted in increased apoptosis and cytosolic expression of ER????. In addition,\ncombining both medications resulted in reduced cell growth and increased the cytotoxic effect of Gefitinib. Conclusion. Tamoxifen\nenhanced advanced LAC cytotoxic effect induced by Gefitinib by arresting ER???? in cytosol.
Loading....