No abstract

Bladder cancer (BC) is a fatal invasive malignancy accounting for approximately 5% of all cancer deaths in humans; however, the underlying molecular mechanisms and potential targeted therapeutics for BC patients remain unclear. We report herein that RAB14 was overexpressed in BC tissues and cells with high metastatic potential and its abundance was significantly associated with lymph node metastasis (P = 0.001), a high-grade tumor stage (P = 0.009), poor differentiation (P < 0.001) and unfavorable prognoses of BC patients (P = 0.003, log-rank test). Interference by RAB14 mediated a reduction in the TWIST1 protein and inhibited cell migration and invasion (P < 0.05). Moreover, silencing RAB14 reduced cell proliferation and induced apoptosis in vitro and suppressed tumorigenesis in a mouse xenograft model. We demonstrated that RAB14-promoted BC cancer development and progression were associated with activation of mitogen-activated protein kinase (MAPK)/extracellular signal-regulated kinase signaling through upregulation of MAPK1/MAPK8 and downregulation of dual-specificity protein phosphatase 6/Src homology 2 domain containing transforming protein/Fos proto-oncogene, AP-1 transcription factor subunit (FOS). We provide evidence that RAB14 acts as a tumor promoter and modulates the invasion and metastatic potential of BC cells via activating the MAPK pathway.

Purpose: Bladder cancer (BC) is the most common urinary cancer among men with a high rate of deaths despite the improved medical technology and treatment. Recent evidence demonstrated that Mex-3 RNA-Binding Family Member C (MEX3C) plays various roles in different biological activities, but its molecular mechanisms underlying the pathogenesis of BC remain unclear yet. The aim of this research was to explore the expression patterns of MEX3C and its biological functions in human BC. Materials and methods: The Cancer Genome Atlas (TCGA) and Oncomine databases were jointly used to analyze the expression of MEX3C in BC and its correlation with the clinicopathological features, while real-time PCR and immunohistochemistry analysis were used to verify the predicted results. Wound-healing assay, Matrigel invasion assay, BODIPY staining and Western blot analysis were used in a cell model to assess the effect of MEX3C on the lipid metabolism, invasion and migration of BC and its mechanisms. Results: MEX3C was highly expressed in BC tissues and cells compared with their normal counterparts, and its expression was positively correlated with the clinicopathological features, especially the invasiveness phenotype. Overexpression of MEX3C accumulated lipid droplets and promoted cell adhesion, invasion and migration. We further demonstrated that MEX3C regulated lipid metabolism and promoted tumor development and progression through activation of JNK signaling and upregulating the JNK downstream protein levels of sterol regulatory element-binding proteins-1, fatty acid synthase and acetyl-CoA carboxylase-1. Conclusion: Here we identified MEX3C as a new oncogene to promote bladder tumorigenesis by regulating lipid metabolism through Mitogen-activated protein kinase/c-Jun N-terminal kinase (MAPK/JNK) pathway. These findings suggest a new role of MEX3C in promoting BC tumorigenesis and provide a novel biomarker or molecular target for diagnosis or treating BC.

Bladder cancer is derived from bladder mucosa and is the most common malignant tumor in urinary system. Long non-coding RNA (lnc-RNA) has high tissue specificity and can participate in cell proliferation and differentiation at various levels, and plays critical roles in occurrence of malignant tumors. This study aims to investigate the suppression of E-cadherin expression by lnc-RNA H19 to enhance bladder cancer metastasis.qRT-PCR was applied to analyze differential expression of lnc-RNA H19 in different bladder cancer tissues and tumor adjacent tissues. Patients clinical data were collected to analyze the correlation between H19 expression level and patient's clinical stage, tumor metastasis. RNA interference was employed to examine the effect of H19 on E-cadherin expression. The regulation of cancer metastasis was investigated on an animal model. H19 expression level was significantly higher in bladder cancer tissue compared to adjacent tissues (p< 0.05), and is correlated with advanced clinical stage (p< 0.05). In those metastatic patients, H19 expression level is significantly higher than those without metastasis (p< 0.05). RNA interference is applied to knockdown H19 expression in bladder cancer cell, and found potentiated E-cadherin expression (p< 0.05), accompanied with weakened metastatic potency (p< 0.05). H19 expression is up-regulated in bladder cancer, and is probably related with cancer clinical stage and metastasis. Cell transfection reveals up-regulation of E-cadherin expression in bladder cancer cells when H19 expression is suppressed, accompanied with weakened metastasis potency.