LncRNA RPL34-AS1 sponges miR-3656 to suppress cell proliferation in colorectal cancer.

The function of long non-coding RNA (lncRNA) RPL34-AS1 and microRNA (miR-3656) has been studied in several types of cancer, but their role in colorectal cancer (CRC) is unclear. We predicted that they could interact with each other; this study was carried out to explore their interaction in CRC. The expression of RPL34-AS1 and miR-3656 in CRC tissues and their paired non-tumor tissues from 62 CRC patients was determined by RT-qPCR. The direct interaction between RPL34-AS1 (both WT and mutant) and miR-3656 was determined by RNA-RNA pull-down assay. The interaction between them was studied with overexpression assay. Their role in cell proliferation was analyzed with BrdU assay. The role of RPL34-AS1 in regulating the expression of ACAP2 was explored by RT-qPCR and Western blot analysis. In this study, increased expression levels of miR-3656 and decreased expression levels of RPL34-AS1 were observed in CRC tissues. MiR-3656 directly interacted with RPL34-AS1, but not the RPL34-AS1 mutant with disrupted binding sites. RPL34-AS1 and miR-3565 did not affect the expression of each other. RPL34-AS1 suppressed the role of miR-3565 in enhancing cell proliferation, while RPL34-AS1 mutant did not affect cell behaviors and the role of miR-3565 in cell proliferation. RPL34-AS1 positively regulated the expression of ACAP2 at both mRNA and protein levels. Therefore, RPL34-AS1 is downregulated in CRC and may sponge miR-3656 to suppress cell proliferation in CRC.