Experimental insights into the role of miR‑10b in the regulation of proliferation and apoptosis of SW480 and SW620 colon cancer cell lines

The present study investigates the potential role of microRNA-10b (miR-10b) in the proliferation and apoptosis of colon cancer cells, with possible associations with WW and C2-domain containing-2 (WWC2) and phosphatase and tensin homolog (PTEN). Bioinformatics analyses were performed using the UALCAN database, TargetScan, and RNAcofold webserver. In vitro experiments were performed to determine the effects of miR-10b inhibition on primary (SW480) and metastatic (SW620) colon cancer cell lines. 2,3-Bis (2-methoxy-4-nitro-5-sulfophenyl)-2 H-tetrazolium-5-carboxanilide (XTT) assay, senescence-associated β-galactosidase assay, dual acridine-orange/ethidium-bromide apoptosis assay, quantitative real-time PCR (qRT-PCR), immunofluorescence and western blot experiments were performed. UALCAN database analysis showed elevated miR-10b expression in colon cancer patients, but no significant association with overall survival was observed ( P = 0.51). TargetScan identified WWC2 and PTEN as important miR-10b targets, and RNAcofold demonstrated the lowest minimum free energy (MFE) values between miR-10b and WWC2 and PTEN . Transfection with miR-10b inhibitor reduced miR-10b expression, decreased cell viability, and increased cellular senescence in both SW480 and SW620 colon cancer cell lines, with higher apoptosis in SW480 cells, while tumor-suppressor miRNAs, namely miR-34a and miR-124a, were upregulated in both the cell lines. MiR-10b inhibition led to increased WWC2 and large tumor suppressor kinases-1/2 ( LATS1/2 ) expression and decreased Yes-associated protein-1 ( YAP1 ) and WW-domain-containing transcription regulator-1 ( WWTR1 ) in SW480 cells, while TEA-domain transcription factor-1 ( TEAD1 ), connective-tissue growth factor ( CTGF ), and GLI-family zinc finger-2 ( GLI2 ) were decreased in both cell lines. BCL2-associated-X-protein ( BAX ), BCL2-associated death-promoter ( BAD ), and Caspase-3 ( CASP3) were elevated, whereas B-cell-lymphoma-2 ( BCL2 ) was reduced in SW480 cell line, with no significant differences between the cell lines. Increased PTEN and decreased cyclin-dependent kinase-6 ( CDK6 ) and cyclin D1 ( CCND1 ) expressions were found in SW480 cells, while proliferating cell nuclear antigen ( PCNA ) expression was reduced in SW620 cells. Immunofluorescence analysis showed reduced nuclear localization of YAP1 and WWTR1; with increased BAX and reduced BCL2 intensity following miR-10b inhibition in both the cell lines. Western blot analysis showed increased WWC2 and PTEN protein expression and decreased BCL2 and WWTR1 protein expression in SW480 cell line. miR-10b possibly promote the proliferation and inhibit the apoptosis of colon cancer cell lines. Not applicable.