Long noncoding RNAs (lncRNAs) constitute an important component of tumor biology, but the molecular mechanism through lncRNAs modulating colorectal cancer (CRC) development and progression remains unclear. Herein we analyzed RNA sequencing data of CRC patients (147 tumor and 47 matched normal tissues) to identify significant lncRNAs involved in CRC. We found 6032 lncRNAs (15%) and selected three up-expressed (ELFN1-AS1, SLCO4A1-AS1, and LINC02418) and six down-expressed (MIR22HG, BCYRN1, SATB2-AS1, LINC01752, CMAHP, and LINC01082) lncRNAs according to fold change and p-value. In Kaplan-Meier survival analysis, CRC patients with high expression of SLCO4A1-AS1 had poorer prognosis than the patients with low expression of SLCO4A1-AS1, and the other lncRNA expressions were not associated with prognosis. To concentrate on the biological function of SLCO4A1-AS1, we investigated the relationship between SLCO4A1-AS1 and SLCO4A1. They were validated in tumor and normal tissues by qRT-PCR and SLCO4A1 expression was also confirmed by immunohistochemistry, indicating their positive correlation. After knocking down of SLCO4A1-AS1, SLCO4A1 protein level was decreased and cell proliferation was suppressed in CRC cell lines. However, SLCO4A1-AS1 level was not changed by knock-down of SLCO4A1. It demonstrated that SLCO4A1-AS1 plays oncogenic role through influencing on SLCO4A1. Thus, SLCO4A1-AS1 might be useful biomarkers for CRC diagnosis and prognosis.

Note: This abstract was not presented at the meeting.

Citation Format: Yuri Choi, Chae Hwa Kwon, Seon Jin Lee, Daye Jeon, Do Youn Park, Sojeong Lee, Ahrong Kim. SLCO4A1-AS1 promotes tumorigenesis of colorectal cancer by stabilizing SLCO4A1 [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2019; 2019 Mar 29-Apr 3; Atlanta, GA. Philadelphia (PA): AACR; Cancer Res 2019;79(13 Suppl):Abstract nr 3566.