LncRNA GABPB1‑IT1 inhibits the tumorigenesis of renal cancer via the miR‐21/PTEN axis

Abstract

AbstractLong noncoding RNA (lncRNA) (GABPB1‑IT1) has been reported to be downregulated in lung cancer, while its expression and function in other cancers are unknown. In this study, the expression levels of GABPB1‑IT1 in tissue samples from 62 ccRCC patients were measured by performing RT‐qPCR. Potential base pairing formed between GABPB1‑IT1 and miR‐21 was explored using the online program IntaRNA 2.0 and further confirmed by Dual‐luciferase activity assay and RNA pulldown assay. The role of GABPB1‑IT1 and miR‐21 in regulating the expression of PTEN was evaluated by RT‐qPCR and Western blot. The role of GABPB1‑IT1, miR‐21, and PTEN in regulating the proliferation of Caki‐2 cells was explored by CCK‐8 assay. It was observed that GABPB1‑IT1 was downregulated in ccRCC and predicted poor survival. GABPB1‑IT1 directly interacted with miR‐21, while it did not regulate the expression of each other. Moreover, upregulation of PTEN, which is a target of miR‐21, was observed in ccRCC cells with overexpression of GABPB1‑IT1. Overexpression of GABPB1‑IT1 and PTEN decreased the proliferation rates of ccRCC cells. In addition, overexpression of GABPB1‑IT1 reduced the enhancing effects of miR‐21 on cell proliferation. Therefore, GABPB1‑IT1 may upregulate PTEN by sponging miR‐21 in ccRCC to inhibit cancer cell proliferation. Our study characterized a novel GABPB1‑IT1/miR‐21/PTEN axis in ccRCC.