Abstract 4455: Identification of novel oncogene, copine-7 (CPNE7), in colorectal cancer

Abstract

Abstract Background: CPNE7, a member of copine family, is composed of calcium-dependent membrane-binding proteins. The encoded protein may play a role in calcium-mediated intracellular processes and membrane trafficking mainly. Although this protein was known as tumor suppressor in breast cancer, we identified the possibility as an oncogene in colorectal cancer. In this study, we performed to evaluate the oncogenic functions of CPNE7 in the colorectal cancer cell line and the clinical significance of CPNE7 expression in colorectal cancer patients. Method: The colorectal cancer cell lines (SW480, SW620, HCT116 and HT29) were transfected with siRNA for knockdown CPNE7. The oncogenic functions were identified in the transfected cell lines and compared them with CPNE7 highly expressing control cell lines. In vitro functional studies included cell proliferation assay, migration assay, invasion assay and semisolid agar colony forming assay. The clinical significance of CPNE7 expression was evaluated in 250 cases of colorectal cancer tissue by immunohistochemistry. Results: The knockdowned cell lines significantly showed lower oncogenic function (proliferation, migration, invasion and colony forming) compared to the CPNE7 highly expressing control cell lines (p<0.05). The overall survival rate was decreased in patients of CPNE7 high expression (p=0.03). Multivariate and univariate Cox-regression analysis showed that CPNE7 high expression was an independent prognostic factor in colorectal cancer (HR=1. 54, 95% CI=1. 00-2.38: p=0. 048 / HR=1. 58, 95% CI=1. 03-2.41: p=0. 032). Conclusion: This study announces that CPNE7 is a novel oncogene, an independent prognostic factor and therapeutic target in colorectal cancer. In the future, studies on in vivo assay and identifying oncogenic signal pathways of CPNE7 in colorectal cancer are necessary. Citation Format: DONGJUN JEONG, Seona Ban, Hyungjoo Kim, Seunghyun Oh, Sanghee Ji, Han Jo Kim, Sang Byung Bae, Tae Sung Ahn, Chang-Jin Kim, Moon Soo Lee, Moo-Jun Baek. Identification of novel oncogene, copine-7 (CPNE7), in colorectal cancer [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 4455. doi:10.1158/1538-7445.AM2017-4455