Abstract 3169: SerpinB2 enhances invadopodia-like structure protrusions and is down-regulated in acquired gefitinib-resistant non-small cell lung cancer cells

Non-small cell lung cancer (NSCLC) is a major type of lung cancer which accounts for approximately 80-85% of all lung cancers. The targeted therapies have significantly improved the survival of advanced NSCLC patients, but the failure of targeted therapy due to the resistance to epidermal growth factor receptor tyrosine kinase inhibitors (EGFR-TKIs), such as gefitinib, is now considered a major problem. SerpinB2 is a component of the urokinase plasminogen activator (uPA) system and has been recognized as a biomarker for the progression and metastasis of lung cancer. We found that SerpinB2 is down-regulated in gefitinib-resistant (H292-Gef) cells compared to gefitinib-sensitive (H292) cells. The low SerpinB2 levels in H292-Gef cells were also associated with an enhancement in invasiveness and increase in the length of invadopodia-like structures in the cells. The effect on invasiveness and gefitinib sensitivity was confirmed by knockdown and overexpression of SerpinB2. In addition, an antitumor agent yuanhuadine (YD) was used to test the possibility to overcome the resistance through the up-regulation of SerpinB2. YD effectively elevated SerpinB2 levels and suppressed invasive properties in H292-Gef cells. Collectively, these findings demonstrate the prospective role of SerpinB2 as a novel biomarker for acquired gefitinib resistance and a potential target for NSCLC treatment. Acknowledgement This study was funded by Basic Science Research Program through the National Research Foundation of Korea (NRF) funded by the Ministry of Education (2015R1D1A1A02062012). Citation Format: Song Yi Bae, Donghwa Kim, Hyen Joo Park, Woong Sub Byun, Ji-Young Hong, Hye-Jung Lee, Sang Kook Lee. SerpinB2 enhances invadopodia-like structure protrusions and is down-regulated in acquired gefitinib-resistant non-small cell lung cancer cells [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr 3169. doi:10.1158/1538-7445.AM2017-3169