Clear cell renal cell carcinoma (ccRCC), the most common subtype of renal cell carcinoma, can easily invade local tissues and metastasize, and is resistant to currently available treatments. Recent studies profiling microRNA expression in ccRCC have suggested miR-30a-5p may be deregulated in these cancer cells. To determine its role and mechanism of action in ccRCC, miR-30-5p expression levels were quantified and functions were analyzed using in vitro and in vivo experiments and bioinformatics. A decrease in miR-30a-5p expression was frequently noted in ccRCC cells and tissues. Importantly, low miR-30a-5p levels were significantly associated with a poor ccRCC patient prognosis. Stable overexpression of miR-30a-5p in 769-P cells was sufficient to prevent cellular proliferation and invasion in vitro and in vivo. Upon further examination, it was found that miR-30a-5p directly targeted the 3′-UTR of ZEB2 and suppressed ccRCC cell epithelial–mesenchymal transition. In addition, miR-30a-5p may be downregulated by the long non-coding RNA DLEU2. Taken together, these data reveal an important role for miR-30a-5p in the regulation of ccRCC proliferation and invasion, and indicate the potential for miR-30a-5p in applications furthering ccRCC prognostics and therapeutics.

Rab25, an epithelial-specific member of the Rab family of small guanosine triphosphatases, is associated with several human cancers. The goal of this study was to determine its function in bladder cancer (BC). We examined the Rab25 expression pattern in two different cohorts of BC patients treated with radical cystectomy by quantitative PCR, western blotting and immunohistochemical staining. A series of in vitro and in vivo assays were performed to elucidate the function of Rab25 in BC and its underlying mechanisms. Rab25 expression was significantly elevated at both the messenger RNA and protein levels in BCs compared with normal bladder tissues. High Rab25 expression was closely associated with lymph node (LN) metastasis and was an independent predictor for poor disease-free survival in BC patients. Downregulation of Rab25 in BC cells markedly inhibited invasive motility in vitro and metastatic potential in vivo. In addition, downregulation of Rab25 in BC EJ and T24 cells increased the expression levels of epithelial markers (E-cadherin and α-catenin) and decreased the levels of mechamechy markers (vimentin and fibronectin). Simultaneously, downregulation of Rab25 in EJ and T24 cells resulted in the inactivation of downstream phosphorylated protein kinase B (p-Akt), phosphorylated glycogen synthase kinase-β (p-GSK-3β) and snail signaling. This study demonstrates that Rab25 can promote BC metastasis through induction of epithelial-mesenchymal transition process and activation of Akt/GSK-3β/Snail signaling pathway; Rab25 expression level can predict LN metastasis and inferior clinical outcome in BC patients.

BackgroundZEB2 has been reportedly shown to mediate the epithelial-to-mesenchymal transition (EMT) and disease aggressiveness in human tumors. However, the expression status of ZEB2 in renal cell carcinoma (RCC) and ZEB2’s clinicopathologic/prognostic significance are poorly understood.Methodology/Principal FindingsIn this study, tissue microarray, immunohistochemistry (IHC) and western blot analyses were utilized to investigate the ZEB2 expression status in RCC and adjacent renal tissue samples. In our study, samples from 116 RCC patients treated with radical nephrectomy were used as a training set to generate a ZEB2 optimal cut-point for patient outcome by receiver operating characteristic (ROC) analysis. For validation, the correlation of ZEB2 expression with the clinical characteristics and patient outcomes in another set (including 113 patients) was analyzed to validate the obtained cut-point. In the training and validation sets, high expression of ZEB2, defined by ROC analysis, predicted a poorer overall survival and progression-free survival, as evidenced by the univariate and multivariate analyses. In different subsets of overall patients, ZEB2 expression was also a prognostic indicator in patients with stage I/II, stage III/IV, grade 1/2 and grade 3/4 disease (P<0.05). Downregulation of ZEB2 by shRNA decreased the migration and invasion ability of 769-P cells in vitro. Furthermore, high ZEB2 expression was positively correlated with vimentin expression and inversely linked to E-cadherin expression in RCC.Conclusions/SignificanceOur findings provide a basis for the concept that high ZEB2 expression in RCC may be important in the acquisition of an aggressive phenotype. This evidence suggests that ZEB2 overexpression (examined by IHC) is an independent biomarker for the poor prognosis of patients with RCC.

PurposeTo examine the role of miR-106b-5p in regulating the cancer stem-cell-like phenotype in clear cell renal cell carcinomas (ccRCC).Experimental DesignReal-time PCR was performed to evaluate miR-106b-5p levels in ccRCC cell lines and patients specimens. A series of in vivo and in vitro assays were performed to confirm the effect of miR-106b-5p on ccRCC stemness phenotype.ResultsccRCC cells and tissues expressed more miR-106b-5p than normal controls. Gain- and loss-of-function studies demonstrated that overexpression of miR-106b-5p in ccRCC cells increased the spheres formation ability and the proportion of side population cells. Ectopic expression of miR-106b-5p in ccRCC cells increased tumour growth rates and the number of metastatic colonies in the lungs by using an orthotopic kidney cancer model and a tail vein injection model, respectively. Mechanistic studies revealed that, miR-106b-5p has an activating effect on Wnt/β-catenin signalling. miR-106p-5p overexpression simultaneously targets multiple negative regulators of the Wnt/β-catenin pathway, namely, LZTFL1, SFRP1 and DKK2. In addition, we also confirmed that miR-106b-5p and its targets expression correlates with the overall-survival of ccRCC patients from TCGA.ConclusionsThese findings suggest that miR-106b-5p mediates the constitutive activation of Wnt/β-catenin signalling, likely serving as a potential therapeutic target for ccRCC.

Increasing evidences show the clinical significance of the interaction between hypoxia and immune in clear cell renal cell carcinoma (ccRCC) microenvironment. However, reliable prognostic signatures based on a combination of hypoxia and immune have not been well established. Moreover, many studies have only used RNA-seq profiles to screen the prognosis feature of ccRCC. Presently, there is no comprehensive analysis of multiomics data to mine a better one. Thus, we try and get it. First, t-SNE and ssGSEA analysis were used to establish tumor subtypes related to hypoxia-immune, and we investigated the hypoxia-immune–related differences in three types of genetic or epigenetic characteristics (gene expression profiles, somatic mutation, and DNA methylation) by analyzing the multiomics data from The Cancer Genome Atlas (TCGA) portal. Additionally, a four-step strategy based on lasso regression and Cox regression was used to construct a satisfying prognostic model, with average 1-year, 3-year and 5-year areas under the curve (AUCs) equal to 0.806, 0.776 and 0.837. Comparing it with other nine known prognostic biomarkers and clinical prognostic scoring algorithms, the multiomics-based signature performs better. Then, we verified the gene expression differences in two external databases (ICGC and SYSU cohorts). Next, eight hub genes were singled out and seven hub genes were validated as prognostic genes in SYSU cohort. Furthermore, it was indicated high-risk patients have a better response for immunotherapy in immunophenoscore (IPS) analysis and TIDE algorithm. Meanwhile, estimated by GDSC and cMAP database, the high-risk patients showed sensitive responses to six chemotherapy drugs and six candidate small-molecule drugs. In summary, the signature can accurately predict the prognosis of ccRCC and may shed light on the development of novel hypoxia-immune biomarkers and target therapy of ccRCC.