Colon cancer is the second leading cause of cancer related deaths in the United States. The nuclear factor kB (NF-kB) is an important family of transcription factors whose aberrant activation has been found in many types of cancer, including colon cancer. Therefore, understanding the regulation of NF-kB is of ultimate importance for cancer therapy. The purpose of this study is to use a novel validation-based insertional mutagenesis (VBIM) strategy to identify novel regulators of NF-kB, and further evaluate their roles in the regulation of NF-kB signaling in colon cancer cells. We infected D1 cells (293 derived cells with hyper active NF-kB activity) with VBIM virus to cause the overexpression of negative regulators of NF-kB, and then further selected the mutant cells with low NF-kB activity under ganciclovir (GCV) treatment. Targeted gene was then identified by using VBIM specific primers. In a preliminary screen, we identified the novel beta-catenin like protein (BCLP) gene as a negative regulator of NF-kB. Overexpression of BCLP led to decreased NF-kB activity by kB reporter assay, while knocking it down had the opposite effect. Furthermore, we found that overexpression of BCLP in HT29 colon cancer cells greatly reduced both the number and the size of colonies that were formed in a soft agar assay, while sh-RNA mediated knockdown resulted in an opposite effect, confirming that BCLP is a tumor suppressor in HT29 cells. Our future experiments aim to further assess the role of BCLP in colon tumor formation in a mouse xenograft model. In summary, by using the novel VBIM technique, we identified BCLP as a novel negative regulator of NF-kB. This discovery could lead to the establishment of BCLP as a potential biomarker and therapeutic target in colon cancer.

Citation Format: Rasika Mundade, Tao Lu. VBIM technology identifies beta-catenin-like protein (BCLP) as a novel negative regulator of NF-kB. [abstract]. In: Proceedings of the 105th Annual Meeting of the American Association for Cancer Research; 2014 Apr 5-9; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2014;74(19 Suppl):Abstract nr 5273. doi:10.1158/1538-7445.AM2014-5273