Abstract 1840: Clinical significance of lincRNA-p21 in colorectal cancer.

Abstract Large Intergenic Noncoding RNAs (LincRNAs) have been recently shown to be novel regulators for both transcription and posttranscriptional/translation. One of them, lincRNA-p21, was regulated by p53 and contributed to apoptosis in mouse embryonic fibroblasts. However, the impact of such regulation on colorectal cancer (CRC) is remained to be determined. In this study, we discovered that the expression level of lincRNA-p21 was increased by elevated wild type p53 induced by Nutlin in HCT116 colon cancer cells. The clinical significance of lincRNA-p21 was further investigated in 2 CRC patient cohorts. The expression of lincRNA-p21 was quantified by the real time qRT-PCR analysis using total RNAs extracted from snap fresh frozen CRC samples. Our results reveal that the expression level of lincRNA-p21 is significantly (P = 0.0208) lower in CRC tumor tissue when compared to the paired normal tissue from the same patient. There is no significant correlation of lincRNA-p21 with p53 status (wild type vs. mutant). Tumors in rectum show higher level of lincRNA-p21 than the ones in colon (P = 0.00005). In addition, lincRNA-p21 in stage III patients was significantly higher than stage I patients (P = 0.007). Elevated level of lincRNA-p21 was significantly associated with higher pT (P = 0.037 between pT 2 and 3), and vascular invasion (P = 0.017). LincRNA-p21 was not significantly associated with patient's overall survival. These results indicate that lincRNA-p21 may contribute to CRC disease progression. Citation Format: Haiyan Zhai, Andrew Fesler, Kristina Schee, Øystein Fodstad, Kjersti Flatmark, Jingfang Ju. Clinical significance of lincRNA-p21 in colorectal cancer. [abstract]. In: Proceedings of the 104th Annual Meeting of the American Association for Cancer Research; 2013 Apr 6-10; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2013;73(8 Suppl):Abstract nr 1840. doi:10.1158/1538-7445.AM2013-1840