Upregulation of lncRNA snoRNA host gene 6 regulates NUAK family SnF1-like kinase-1 expression by competitively binding microRNA-125b and interacting with Snail1/2 in bladder cancer.

Backgrounds/aims: Numerous studies have reported that long noncoding RNAs (lncRNAs) play critical roles in the development and progression of bladder cancer (BC). LncRNA snoRNA host gene 6 (SNHG6) is ectopically expressed in tumor tissues of patients with BC and BC cell lines. However, little is known about the molecular mechanism of SNHG6-mediated bladder urothelial carcinoma cell migration and invasion.

Methods: We detected the SNHG6 levels in human BC specimens and cell lines by quantitative real-time polymerase chain reaction and Western blot, and investigated its role in BC using in vitro assays.

Results: We showed that overexpression of SNHG6 induced epithelial-mesenchymal transition (EMT) and promoted the migration and invasion capabilities of BC cells. Mechanistically, SNHG6 induced EMT of BC cells by upregulating the expression levels of Snail1/2 and regulated BC cell migration and invasion by tumor suppressive hsa-miR-125b and its target gene NUAK Family Kinase 1 (NUAK1). Furthermore, we found that SNHG6 was positively correlated with Snail1/2 expression, and negatively correlated with hsa-miR-125b expression in BC specimens. Further study showed that SNHG6 repressed hsa-miR-125b expression to upregulate Snail1/2. Conversely, hsa-miR-125b knockdown augmented SNHG6 expression in BC cells.

Conclusion: Overall, our study demonstrated that SNHG6 promotes BC cell migration and invasion partly via the hsa-miR-125b/Snail1/2/NUAK1 pathway. Therefore, SNHG6 may be a potential prognostic biomarker in BC, and targeting hsa-miR-125b/Snail1/2/NUAK1 axis may be a promising therapeutic approach for BC patients.