Abstract 3842: Histone methyltransferase G9a promotes migration, invasion of non-small cell lung cancer through enhancing FAK and NF-kB signal pathways

Abstract

Abstract Overexpression of euchromatic histone methyltransferase 2 (EHMT2 or G9a) is associated with carcinogenesis and poor prognosis in a number of cancer types. In this study, we investigated the effect of G9a on invasion of non-small cell lung cancer (NSCLC) cells and the mechanism underlying cancer cell invasion. Knockdown of G9a was shown to drastically suppress in vitro cellular proliferation, migration, and invasion of A549 and H1299 NSCLC cells, while overexpression of G9a significantly enhanced the proliferation and invasion of these NSCLC cells. Additionally, knockdown of G9a led to significant decrease in expression of focal adhesion kinase (FAK) gene and activation of FAK pathway. UNC0638, a selective inhibitor of G9a, significantly suppressed both the proliferation, migration and invasion of these NSCLC cells, and concurrently led to a dramatic drop of global demethylation of H3K9 (H3K9me2) and suppressed the activation of FAK pathway. In addition, Defactinib, a potent FAK inhibitor, partially abolished the enhanced invasion by overexpression of G9a in these NSCLC cells. Furthermore, G9a was proved to regulate nuclear NF-κB transcriptional activity in NSCLC cells, and NF-κB inhibitor partially abolished the activated FAK signaling pathway by overexpressed G9a, which indicates that G9a-enhanced invasion and activation of FAK pathway may be mediated by NF-κB transcriptional activity. Notably, immunohistochemistry analysis further revealed that activation of FAK pathway was associated with overexpressed G9a in about 150 cases of NSCLC tissues. Altogether, these data have strongly demonstrated that G9a may promote invasion of NSCLC cells by upregulating FAK protein and pathway via enhancing NF-κB transcriptional activity, indicating a therapeutic implication of targeting these two pathways in NSCLC with overexpressed G9a. Citation Format: Ting Sun, Keqiang Zhang, Rajendra P. Pangeni, Wendong Li, Dan J. Raz. Histone methyltransferase G9a promotes migration, invasion of non-small cell lung cancer through enhancing FAK and NF-kB signal pathways [abstract]. In: Proceedings of the Annual Meeting of the American Association for Cancer Research 2020; 2020 Apr 27-28 and Jun 22-24. Philadelphia (PA): AACR; Cancer Res 2020;80(16 Suppl):Abstract nr 3842.