Integrated Genomic Approaches Identify Upregulation Of Scrn1 As A Novel Mechanism Associated With Acquired Resistance To Erlotinib In Non Small Cell Lung Cancer Cells With Oncogenic Egfr Mutation

Proceedings: AACR 107th Annual Meeting 2016; April 16-20, 2016; New Orleans, LATherapies targeting the tyrosine kinase activity of Epidermal Growth Factor Receptor (EGFR) have been proven to be effective in treating a subset of non-small cell lung cancer (NSCLC) patients harboring activating EGFR mutations. Inevitably these patients develop resistance to the EGFR-targeted tyrosine kinase inhibitors (TKIs). Here, we performed integrated genomic analyses using an in vitro system to uncover alternative genomic alterations responsible for acquired resistance to EGFR-TKIs. Specifically, we identified 80 genes whose expression is significantly increased in the resistant clones and RNAi-based systematic synthetic lethal screening revealed that suppression of one upregulated transcript, SCRN1, a secernin family member, restores sensitivity to erlotinib by enhancing inhibition of PI3K/AKT signaling pathway. Furthermore, we detected increased levels of SCRN1 in 5 of 11 lung tumor specimens from EGFR-TKIs refractory patients by immunohistochemistry. Taken together, we propose that upregulation of SCRN1 is an additional mechanism associated with acquired resistance to EGFR-TKIs in a subset of lung cancer patients and that its suppression serves as a novel therapeutic strategy to overcome drug resistance in these patients.Citation Format: Nayoung Kim, Ahye Cho, Hideo Watanabe, Yoon-La Choi, Meraj Aziz, Michelle Kassner, Je-Gun Joung, Angela KJ Park, Joshua Francis, Joon Seol Bae, Soo-min Ahn, Kyoung-Mee Kim, Joon-Oh Park, Woong-Yang Park, Myung-Ju Ahn, Keunchil Park, Hongwei Holly Yin, Jeonghee Cho. Integrated genomic approaches identify upregulation of SCRN1 as a novel mechanism associated with acquired resistance to erlotinib in non small cell lung cancer cells with oncogenic EGFR mutation. [abstract]. In: Proceedings of the 107th Annual Meeting of the American Association for Cancer Research; 2016 Apr 16-20; New Orleans, LA. Philadelphia (PA): AACR; Cancer Res 2016;76(14 Suppl):Abstract nr 2931.