Ubiquitin-conjugating enzyme 2C promotes malignant progression of malignant rhabdoid tumor of the kidney via the Wnt/β-catenin signaling pathway

Abstract:

Objective To investigate the influence of ubiquitin-conjugating enzyme 2C（UBE2C） on malignant rhabdoid tumor of the kidney（MRTK） and its mechanism of action.Methods Western blot and immunofluorescence assay were used to verify the expression of UBE2C in MRTK clinical specimens and G401 cells. Gene expression data of MRTK were downloaded from the TARGET database for validation，and the Kaplan-Meier method was used to assess the association between UBE2C and prognosis. Small interfering RNA（siRNA） was used to inhibit the expression of UBE2C in G401 cells. CCK-8 assay was used to observe the proliferation of G401 cells after transfection，flow cytometry was used to observe cell apoptosis，and scratch assay and Transwell assay were used to observe the changes in cell migration and invasion abilities. Gene Set Enrichment Analysis（GSEA） was used to explore the pathways regulated by UBE2C，and Western blot was used to verify the expression of pathway proteins.Results The expression of UBE2C in MRTK clinical specimens was 3.189±1.900 times that in adjacent control samples（P=0.033）. The expression of UBE2C in G401 cells was 2.092±0.231 times that in HEK293 cells（P=0.000）. The Kaplan-Meier survival analysis showed that the patients with high UBE2C expression tended to have a worse prognosis（P=0.019），and the patients with stage 4 MRTK had a significantly higher expression of UBE2C than the patients in the early stage（680.9±167.7 vs. 560.5±166.9，P=0.021）. Our research group successfully knocked down the expression of UBE2C to 0.446±0.058 folds（P=0.000） by using siRNA，and it was found that UBE2C knockdown inhibited the proliferation，invasion，and migration of G401 cells and promoted the apoptosis of G401 cells（P=0.000）. GSEA enrichment analysis revealed that UBE2C was associated with the Wnt/β-catenin signaling pathway（P=0.000），and UBE2C knockdown inhibited the Wnt/β-catenin signaling pathway and epithelial-mesenchymal transition（EMT）（P=0.000）.Conclusion The high expression of UBE2C in MRTK is associated with poor prognosis and is involved in the regulation of the Wnt/β-catenin signaling pathway，and inhibition of UBE2C can inhibit proliferation，migration，invasion，and EMT and promote apoptosis in MRTK.