Abstract GMM-035: TARGETING SPSB1 SENSITIZES PLATINUM-RESISTANT OVARIAN CANCER CELLS TO CISPLATIN

Abstract

Abstract OBJECTIVE: Emergence of chemoresistance remains a critical clinical issue responsible for treatment failure in patients with ovarian cancer. The precise mechanisms underlying the development of chemoresistance are not fully understood. In our previous study using methylomic and transcriptomic analyses, SPRY domain-containing SOCS box protein 1 (SPSB1) was found to be differentially expressed between cisplatin-sensitive and –resistant ovarian cancer cells. Here, we investigated the roles of SPSB1 as a new therapeutic target for ovarian cancer cells resistant to cisplatin. METHODS: Knockdown of SPSB1 gene was performed by transfection of SPSB1 siRNA. Ovarian cancer cell lines were cultured for 5 days and 12 days after transfection for MTT assay and colony forming assay, respectively. Protein level was analyzed by western blot analysis. Cell migration assay was performed using Boyden chamber method. RESULTS: Knockdown of SPSB1 using RNAi method dramatically inhibited cell viability and migratory capability of ovarian cancer cells. Also, SPSB1 knockdown significantly induced CDK inhibitors, p21 and p27 and inhibited anti-apoptotic Bcl-2, indicating that SPSB1 inhibition induces cell cycle arrest and apoptosis in ovarian cancer cells. CONCLUSION: Our results suggest that SPSB1 might be a potential therapeutic target for cisplatin-resistant ovarian cancer. Citation Format: Mi-Kyung Kim, Hyun-Jung Kim, Yun Hwan Kim, Seung Cheol Kim, Woong Ju. TARGETING SPSB1 SENSITIZES PLATINUM-RESISTANT OVARIAN CANCER CELLS TO CISPLATIN [abstract]. In: Proceedings of the 12th Biennial Ovarian Cancer Research Symposium; Sep 13-15, 2018; Seattle, WA. Philadelphia (PA): AACR; Clin Cancer Res 2019;25(22 Suppl):Abstract nr GMM-035.