SESSION TITLE: Lung Cancer Posters SESSION TYPE: Original Investigation Posters PRESENTED ON: October 18-21, 2020 PURPOSE: The efficacy of Epidermal growth factor receptor (EGFR)-tyosine kinase inhibitors is significantly limited by various resistance mechanisms to those drugs. Vascular endothelial growth factor (VEGF) and EGFR inhibitors have become key therapies in lung cancer. Resveratrol (RSV, 3, 5, 4-trihydroxystilbene), a naturally polyphenolic phytoalexin has anti-inflammatory and anti-carcinogenic and angiogenesis regulating properties. The purpose of this study was to investigate the effect of RSV in gefitinib resistant PC9 (PC9/G) cell lines and establish if VEGF signaling may be a potential target. METHODS: Two cell lines, PC9 and PC9/G, were selected for this study. Cells were exposed to 0.1, 1.0, 10, 20 uM gefitinib (Gef) and/or 40 uM RSV. Cell viability was measured by MTT assay. The expression levels of target genes were examined with ELISA and western blot assay according to gefitinib and RSV treatment. RESULTS: To assess whether RSV could sensitize PC9/G cells to Gef. We evaluated the effects combination treatment of Gef and RSV on the proliferation of PC9/G cells. Compared with Gef teatment alone, Gef + RSV treatment was more potent growth inhibitory effects. Cell migration was more inhibited by Gef+RSV treatment than Gef alone. Western blot analysis showed that RSV repressed the expressions of VEGFR and multiple downstream protein kinases such as Akt, mTOR, and p70S6K. Survivin and cleaved PARP, apoptotic proteins, were enhanced after RSV + Gef treatment in PC9/G cells. CONCLUSIONS: Our findings suggested that RSV combined with Gef had additional antitumor effects in PC-9/GR cells. CLINICAL IMPLICATIONS: Apoptotic effects was mediated by multiple mechanism involving suppression of VEGF expression via inhibition of PI3K/Akt/mTOR pathway. DISCLOSURES: No relevant relationships by Hye Seon Kang, source=Web Response No relevant relationships by Yong hyun Kim, source=Web Response No relevant relationships by SOON SEOG KWON, source=Web Response no disclosure on file for Eung Gu Lee; No relevant relationships by JIWON RYOO, source=Web Response