UBE2T promotes proliferation and regulates PI3K/Akt signaling in renal cell carcinoma

Renal cell carcinoma (RCC) is a common malignant tumor globally. The overall survival of patients with RCC is poor; one important factor is tumor heterogeneity. Ubiquitin-conjugating enzyme E2T (UBE2T) has been reported to act as an oncogene in various types of cancer; however, its role in RCC has yet to be investigated. In the present study, UBE2T was demonstrated via reverse transcription-quantitative PCR analysis to be significantly upregulated in RCC samples and cell lines compared with in normal tissue and cells. Additionally, UBE2T expression was significantly associated with late tumor stage and high grade in patients with RCC, and patients with high UBE2T expression exhibited poor prognosis compared with patients with low expression. Following knockdown of UBE2T in 786-O cells using RNA interference technology, the proliferation and colony formation of cells were inhibited as determined by an MTT assay and crystal violet staining, respectively; however, the migration and invasion of 786-O cells were not affected, as determined by wound-healing assay and Transwell assays, respectively. Xenograft RCC tumor growth in vivo was also significantly suppressed. The expression levels of two mesenchymal cell markers, N-cadherin and vimentin, were reduced following UBE2T knockdown, whereas E-cadherin and fibronectin levels were increased as determined by western blotting, indicating that epithelial-mesenchymal transition was suppressed. In addition, the phosphorylation levels of PI3K, Akt and mTOR were notably decreased following UBE2T knockdown, but were increased when UBE2T was overexpressed. Wortmannin, an Akt inhibitor, reversed the UBE2T overexpression-induced increase in the phosphorylation of PI3K, Akt and mTOR. Similarly, the UBE2T overexpression-induced promotion of 786-O cell proliferation was also attenuated by wortmannin. In conclusion, UBE2T promoted the proliferation of RCC cells by regulating PI3K/Akt signaling, suggesting it may be a novel target for the treatment of patients with RCC.