Abstract

Renal cell carcinoma (RCC) is a prevalent malignancy of the urinary system, but the role of lncRNA DLGAP1-AS2 in epithelial–mesenchymal transition (EMT) in RCC remains unclear. In this study, shRNA was transfected into RCC cells to reduce lncRNA DLGAP1-AS2 expression. The effects of lncRNA DLGAP1-AS2 knockdown on RCC cell proliferation, cell cycle, invasion, and migration were evaluated using CCK-8, flow cytometry, Transwell, and scratch assays, respectively. Western blotting was used to measure the protein expression of E-cadherin, EGFR, Vimentin, and α-SMA, while immunofluorescence was performed to visualize E-cadherin expression. An RNA pull-down assay confirmed the interaction between lncRNA DLGAP1-AS2 and transforming growth factor-beta (TGF-β), and nucleocytoplasmic fractionation together with qRT-PCR was used to analyze its subcellular localization. RCC cells were transfected with lncRNA DLGAP1-AS2 shRNA, treated with a TGF-β inhibitor, or both, and qRT-PCR and Western blotting were subsequently used to quantify the expression of Snail, Slug, E-cadherin, EGFR, Vimentin, α-SMA, TGF-β, TGF-βRI, and p-Smad3. Knockdown of lncRNA DLGAP1-AS2 decreased proliferation, migration, and invasion and was accompanied by a shortened G0/G1 phase. Compared with the NC-shRNA group, the lncRNA DLGAP1-AS2 shRNA group showed significantly lower levels of EGFR, Vimentin, and α-SMA, along with higher E-cadherin expression. TGF-β was identified as a target of lncRNA DLGAP1-AS2, and lncRNA DLGAP1-AS2 was found to be localized in the cytoplasm. Treatment with a TGF-β inhibitor enhanced the effects of lncRNA DLGAP1-AS2 knockdown on EMT in RCC cells. Moreover, transfection with lncRNA DLGAP1-AS2 shRNA inhibited the TGF-β/Smad signaling pathway. These findings suggest that reduced expression of lncRNA DLGAP1-AS2 may contribute to RCC suppression by modulating the TGF-β/Smad signaling pathway to inhibit EMT. Graphical