LncRNA ST8SIA6-AS1 promotes colorectal cancer cell proliferation, migration and invasion by regulating the miR-5195/PCBP2 axis.

Long non-coding RNAs (lncRNAs) have been reported to play a vital role in the development and progression of various cancers, including colorectal cancer (CRC). Although the dysregulation of lncRNA ST8SIA6-AS1 participates in the development of multiple malignancies, the underlying molecular mechanisms of ST8SIA6-AS1 in regulating CRC progression remain to be fully discovered. The expression level of lncRNA ST8SIA6-AS1 was examined in the tumor tissues and paracancerous tissues of CRC patients. Quantitative Real Time-Polymerase Chain Reaction (qRT-PCR) was utilized to examine the expression levels of ST8SIA6-AS1, miR-5195, and Poly-(C) Binding Protein 2 (PCBP2). The protein expression level of PCBP2 was detected by Western blotting. MTT assay was performed to measure the proliferation of HCT-116 and SW480 cells. Cell migration and invasion abilities were measured by transwell assay. Luciferase reporter assay was used to examine the interaction between miR-5195 and ST8SIA6-AS1 or PCBP2. This study revealed that lncRNA ST8SIA6-AS1 was upregulated in CRC tissues and cells. Knockdown of ST8SIA6-AS1 inhibited proliferation, migration, and invasion of CRC cells. Moreover, ST8SIA6-AS1 was proved to inhibit miR-5195 expression by directly targeting miR-5195. In addition, it was demonstrated that overexpression of miR-5195 inhibited CRC progression. Furthermore, PCBP2 was shown to enhance sh-ST8SIA6-AS1 and miR-5195 mimics-attenuated cell proliferation, migration, and invasion by directly binding to miR-5195. Our study revealed that ST8SIA6-AS1 promoted CRC progression via the miR-5195/PCBP2 axis. This study may provide an improved understanding of the pathogenesis of CRC.