Long noncoding RNA SNHG12 modulated by human papillomavirus 16 E6/E7 promotes cervical cancer progression via ERK/Slug pathway.

Recently, long noncoding RNA SNHG12 has been reported to be dysregulated in various types of cancer. This study investigated its biological function and the underlying molecular mechanism in cervical squamous cell carcinoma (CSCC). We found that SNHG12 was significantly overexpressed in CSCC tissues. Further evidence showed that human papillomavirus (HPV) type 16 E6 and E7 might regulate the expression level of SNHG12 by modulating transcription factor c-Myc. Functional experiments suggested that SNHG12 knockdown dramatically repressed CSCC cells proliferation, migration, and invasion while induced apoptosis in vitro as well as suppressed tumor growth in vivo. In addition, SNHG12 could facilitate epithelial-mesenchymal transition through ERK/Slug/E-cadherin pathway at least in part. Our findings highlight SNHG12 functions as an oncogenic long noncoding RNA in malignant phenotype and tumorigenesis of CSCC, which implicate it may be a potential target for CSCC treatment.

High expression of TMEM40 is associated with the malignant behavior and tumorigenesis in bladder cancer.

BACKGROUND: Bladder cancer (BCa) is one of the most common cancers in the urinary system among the world. Previous studies suggested that TMEM40 expression level was significantly associated with clinicopathological parameters including histological grade, clinical stage and pT status of bladder cancer. However, the molecular mechanism of TMEM40 in BCa remains poorly understood. METHODS: Real-time quantitative RT-PCR (qRT-PCR) and western blot (WB) were used to examine the expression levels of TMEM40 in BCa tissues, paired non-cancer tissues and cell lines. A series of experiments, including CCK-8, wound healing, flow cytometry, transwell and EdU assays were performed to assess the effects of TMEM40 on cell proliferation, cell cycle and apoptosis, migration and invasion. In addition, tumor growth was evaluated in vivo using a xenogenous subcutaneously implant model. All statistical analyses were executed by using the SPSS 20.0 software. All experimental data from three independent experiments were analyzed by Student's t test and results were expressed as mean ± standard deviation. RESULTS: In this study, we identified the role of TMEM40 in the tumorigenesis of bladder cancer and found that it was upregulated in bladder cancer tissues and cell lines, compared with their normal counterparts. The results demonstrated that effective silence of TMEM40 expression suppressed cell proliferation, blocked G1-to-S cell cycle transition, and inhibited cell migration and invasion in human bladder 5637 and EJ cell lines. Consistently, in vivo data showed that TMEM40 silencing could dramatically decreased tumor growth. Further study revealed that TMEM40 knockdown resulted in accumulation of p53 and p21 protein and decrease of c-MYC and cyclin D1 protein. CONCLUSION: These data suggest that TMEM40 represents a potential oncogene, which exert a crucial role in the proliferation and apoptosis via the p53 signaling pathway in BCa, thus probably serve as a novel candidate biomarker and a potential therapeutic target for patients with BCa.

Myosin 1b promotes cell proliferation, migration, and invasion in cervical cancer.

OBJECTIVE: Recent evidence suggests an important role of Myosin 1b (Myo1b) in the progression of several cancers, including prostate cancer and head and neck squamous cell carcinoma (HNSCC). However, the contribution of Myo1b to cervical cancer (CC) remains elusive. METHODS: Quantitative reverse transcription polymerase chain reaction (qRT-PCR), immunohistochemistry and western blotting assays were used to confirm the expression of Myo1b in CC tissues compared with matched non-tumor tissues and CC cells, and analyze its clinical significance. In vitro, RNA interference (siRNA or shRNA) was used to investigate the biological function and underlying mechanism of Myo1b in cervical carcinogenesis. Furthermore, tumor growth was evaluated in vivo using a xenogenous subcutaneously implant model. RESULTS: Here, for the first time we reported that Myo1b expression was significantly increased in human CC, compared to cervical intraepithelial neoplasia (CIN) and normal cervical tissues and that the upregulation of Myo1b was significantly correlated with FIGO Stage, HPV infection, lymph node metastasis and pathological grade. In vitro, knockdown of Myo1b significantly suppressed proliferation, migration, and invasion of CaSki and SiHa cells, and markedly decreased the MMP1/MMP9 activities. Also, silencing the expression of Myo1b dramatically repressed tumor growth in a mouse xenograft model. Further investigations showed that HPV16 E6 or E7 could enhance the expression of Myo1b via upregulating c-MYC. CONCLUSION: Taken together, our data suggested a potential role of Myo1b in cervical carcinogenesis and tumor progression and provided novel insights into the mechanism of how this factor promotes cell proliferation, migration, and invasion in CC cells.

Anti-tumor activity of phenoxybenzamine hydrochloride on malignant glioma cells.

Phenoxybenzamine hydrochloride (PHEN) is a selective antagonist of both α-adrenoceptor and calmodulin that exhibits anticancer properties. The aim of this study was to explore the anti-tumor function of PHEN in glioma. Cell proliferation assay was used to assess glioma cell growth. Migration and invasion capacity of glioma cells was monitored by wound-healing and transwell assay, respectively. Neurosphere formation test was adopted for the tumorigenesis of glioma cells, which was also confirmed by soft agar cloning formation test in vitro and a nude mouse model in vivo. Finally, we explored the potential pathway utilized by PHEN using Western blot and immunofluoresce staining. PHEN exhibited a significant inhibitory effect on the proliferation of both U251 and U87MG glioma cell lines in a positive dose-dependent manner. PHEN apparently attenuated the malignancy of glioma in terms of migration and invasion and also suppressed the tumorigenic capacity both in vitro and in vivo. Mechanism study showed that PHEN promoted tumor suppression by inhibiting the TrkB-Akt pathway. The results of the present study demonstrated that PHEN suppressed the proliferation, migration, invasion, and tumorigenesis of glioma cells, induced LINGO-1 expression, and inhibited the TrkB-Akt pathway, which may prove to be the mechanisms underlying the anti-tumor effect of PHEN on glioma cells.

MiR-519d facilitates the progression and metastasis of cervical cancer through direct targeting Smad7.

BACKGROUND: MicroRNAs (miRNAs) play pivotal roles in the development of various cancer types, including cervical cancer. METHODS AND RESULTS: In this study, we showed that miR-519d, a miRNA within the chromosome 19 miRNA cluster, was significantly upregulated in cervical cancer tissues, compared with non-tumorous cervical samples. Suppression of miR-519d markedly attenuated the migration and invasion of HeLa and SiHa cervical cancer cells. Additionally, miR-519d inhibited the apoptosis of cervical cancer cells, and the proliferation of cervical cancer cells was also affected following transfection of miR-519d inhibitor. Moreover, we identified Smad7 to be a novel target of miR-519d in cervical cancer cells. MiR-519d matched the 3'-UTR of Smad7 mRNA. Transfection with miR-519d mimics led to apparent downregulation of Smad7 both at the mRNA and protein levels. Luciferase reporter analysis revealed that miR-519d reduced the luciferase activity of Smad7 mRNA 3'-UTR through matching site-dependent manner. And more notably, suppression of Smad7 remarkably restored the migration and invasion of miR-519d-depleted cervical cancer cells. CONCLUSION: Taken together, these findings implicated that miR-519d promoted the progression and metastasis of cervical cancer through targeting Smad7.

Reduced expression of PinX1 correlates to progressive features in patients with prostate cancer.

BACKGROUND: Pin2/TRF1 binding protein X1 (PinX1) has been identified as an endogenous telomerase inhibitor and a major haploinsufficient tumor suppressor gene. Increasing evidence suggests that reduced expression of PinX1 plays a key role in tumorigenesis. However, the PinX1 expression status and its correlation with the clinicopathological features in prostate cancer (PCa) have not been investigated. METHODS: PinX1 mRNA and protein expression in PCa and adjacent normal prostate tissues were evaluated by real-time quantitative RT-PCR (qRT-PCR) and western blotting. The clinicopathological significance of PinX1 was investigated by immunohistochemistry (IHC) analysis on a PCa tissue microarray (TMA). The cut-off score for positive expression of PinX1 was determined by the receiver operating characteristic (ROC) analysis. The correlation between PinX1 expression and clinicopathological features of PCa was analyzed by Chi-square test. RESULTS: Reduced expression of PinX1 mRNA and protein was observed in the majority of PCa, compared with their paired adjacent normal prostate tissues. When PinX1 positive expression percentage was determined to be above 60% (area under ROC curve = 0.833, P = 0.000), positive expression of PinX1 was observed in 100% (8/8) of normal prostate tissues and 32.5% (13/40) of PCa tissues by IHC. Reduced expression of PinX1 in patients was correlated with advanced clinical stage (χ(2) = 10.230, p = 0.017), high Gleason score (χ(2) = 4.019, p = 0.045), positive regional lymph node metastasis (χ(2) = 10.852, p = 0.004) and distant metastasis (χ(2) = 7.965, p = 0.005). CONCLUSIONS: Our findings suggest that reduced expression of PinX1 is correlates to progressive features in patients with PCa and may serve as a potential marker for diagnosis.

The expression and clinical significance of HERC4 in breast cancer.

BACKGROUND: Increasing evidence suggest that ubiquitin-proteasome system (UPS) plays a key role in tumorigenesis. HERC4 is a recently identified ubiqutin ligase. However, the expression status and biological functions of HERC4 in cancers are not clearly. METHODS: We evaluated the HERC4 expression in breast cancer cell lines and breast tumor tissues by quantitative real-time PCR and western blot analysis. To investigate the clinicopathological significance of HERC4, immunohistochemistry analysis for HERC4 was performed on a tissue microarray including 13 benign fibroadenoma, 15 intraductal carcinoma, 120 histologically confirmed invasive ductal carcinoma. Receiver operating characteristic (ROC) analysis was applied to determine the optimal cut-off score for positive expression of HERC4, when HERC4 positive expression percentage was above 60%, tumor was defined as "positive". RESULTS: HERC4 was up-regulated in breast cancer cell lines and breast tumor tissues compared to non-tumorigenic cell line and adjacent normal breast tissues. According to ROC analysis, HERC4 positive expression was detected in 1/16 (6.3%) of normal breast tissue, in 3/13 (23.1%) of fibroadenoma, in 6/15 (40%) of intraductal carcinoma and 66/120 (55%) of invasive ductal carcinoma. Positive expression of HERC4 was positively correlated with pT status, pN status, clinical stage and histological grade of patients with invasive ductal carcinoma (p < 0.05). CONCLUSIONS: Our findings suggest that HERC4 was a significant diagnostic marker for invasive ductal carcinoma of the breast.

Elevated expression of myosin VI contributes to breast cancer progression via MAPK/ERK signaling pathway.

Breast cancer (BC) is one of the most common malignancies occurring in women worldwide, and its incidence is increasing each year. Accumulating evidence indicated that Myosin VI (MYO6) functions as a gene associated with tumor progression in several cancers. However, the potential role of MYO6 and its underlying mechanisms in the development and progression of BC remains unknown. Herein, we examined the expression levels of MYO6 in BC cells and tissues by western blot and immunohistochemistry. Loss- and gain-of-function investigations in vitro were performed to determine the biological functions of MYO6. And in vivo effects of MYO6 on tumorigenesis were investigated in nude mice. Our findings showed that the expression of MYO6 was up-regulated in breast cancer, and its high expression was correlated with poor prognosis. Further investigation exhibited that silencing the expression of MYO6 significantly inhibited cell proliferation, migration and invasion, whereas overexpression of MYO6 enhanced these abilities in vitro. Also, reduced expression of MYO6 significantly retarded the tumor growth in vivo. Mechanistically, Gene Set Enrichment Analysis (GSEA) revealed that MYO6 was involved in mitogen-activated protein kinase (MAPK) pathway. Moreover, we proved that MYO6 enhanced BC proliferation, migration and invasion via increasing the expression of phosphorylated ERK1/2. Taken together, our findings highlight the role of MYO6 in promoting BC cell progression through MAPK/ERK pathway, suggesting it may be a new potential therapeutic and prognostic target for BC patients.

Upregulation of TMEM40 is associated with the malignant behavior and promotes tumor progression in cervical cancer.

OBJECTIVE: Recent studies indicated that transmembrane protein 40 (TMEM40) is associated with several types of cancers but is not clear in cervical cancer (CC). The study aimed to examine the role of TMEM40 in CC and related mechanisms. METHODS: The expression of TMEM40 in CC tissues and cell lines was studied with western blot and real-time quantitative RT-PCR. The effect of TMEM40 on proliferation was evaluated by CCK-8, EdU and colony formation assay. The migration, invasion, cell cycle and apoptosis of CC cells were studied with wound healing, transwell assays and flow cytometry. Tumor growth was evaluated in vivo using a xenogenous subcutaneously implant model. RESULTS: The results revealed that the TMEM40 elevation in CC tissues and cell lines was closely correlated with tumor size and lymph node metastasis in clinical patients. Upregulation of TMEM40 with OE-TMEM40 vector promoted the invasion, migration and proliferation, inhibited the apoptosis and led to distinct S cell cycle arrest in CC cell lines. Silencing TMEM40 with shRNA inhibited the invasion, migration and proliferation, promoted apoptosis and led to a G0/G1 cell cycle arrest in CC cell lines. Silence of TMEM40 downregulated the expression of c-MYC, Cyclin D1, matrix metalloproteinase-1 (MMP-1) and matrix metalloproteinase-9 (MMP-9), but in contrast, activated p53 and several apoptosis related proteins such as p53, Caspase-3, Caspase-9 and PARP1. In addition, TMEM40 silencing dramatically decreased tumor growth in mice models. CONCLUSION: The present study demonstrates that TMEM40 upregulation can be a potential prognostic biomarker and contribute to CC development.

The association between two polymorphisms in the TS gene and risk of cancer: a systematic review and pooled analysis.

Thymidylate synthase (TS) is an important enzyme involved in folate metabolism and catalyzes methylation of deoxyuridine monophosphate to deoxythymidine monophosphate, which is essential for DNA replication. Thymidylate synthase enhancer region (TSER) and TS1494del6, two functionally important and ethnically diverse polymorphisms mapping to its gene region, are the most extensively studied. Considering the potential influence of altering TS activity, it is plausible that TS polymorphisms might play a role in the development of cancer. Although the effects of TS polymorphisms on susceptibility to human cancer have been investigated in many studies, the results remain conflicting rather than conclusive. To resolve these conflicts, we performed a quantitative synthesis of the evidence on the association between these two polymorphisms and cancer risk, including 63 studies (19,707 cases and 27,398 controls) for TSER polymorphism and 39 studies (13,489 cases and 16,297 controls) for TS1494del6 polymorphism. Our meta-analysis suggested that these two polymorphisms are not associated with cancer risk when all studies were pooled together. In the stratified analyses, we found that individuals with 2R/2R genotype had a significantly higher cancer risks among Asians (2R/2R vs. 3R/3R: odds ratio [OR] = 1.24, 95% confidence interval (95% CI) = 1.05-1.45; recessive model: OR = 1.23, 95% CI = 1.05-1.44). Further analyses revealed that 2R/2R genotype was significantly associated with an increased risk of gastroesophageal cancer among Asians, whereas it might provide protecting effects against colorectal cancer risk in a dominant genetic model for Caucasians. Additionally, TS1494del6 polymorphism may contribute to genetic susceptibility of breast cancer among Asians.

Association between SHBG Asp327Asn (rs6259) polymorphism and breast cancer risk: a meta-analysis of 10,454 cases and 13,111 controls.

Sex hormone-binding globulin (SHBG) is a plasma glycoprotein that plays an important role in breast cancer pathophysiology and risk definition, since it regulates the bioavailable fraction of circulating estradiol. Epidemiological studies have evaluated the association between SHBG Asp327Asn polymorphism and breast cancer risk in diverse populations. However, the results remain conflicting rather than conclusive. This meta-analysis of literatures was performed to derive a more precise estimation of the relationship. A total of 10 studies were identified for the meta-analysis, including 10,454 cases and 13,111 controls for SHBG Asp327Asn polymorphism. When all studies were pooled into the meta-analysis, there was no evidence for significant association between SHBG Asp327Asn polymorphism and breast cancer risk (for Asn/Asn vs. Asp/Asp: OR = 1.20, 95 % CI = 0.94-1.55; for Asp/Asn vs. Asp/Asp: OR = 0.94, 95 % CI = 0.87-1.01; for dominant model: OR = 0.95, 95 % CI = 0.90-1.02; for recessive model: OR = 1.22, 95 % CI = 0.95-1.57). In the subgroup analyses by ethnicity, menopausal status, and source of controls, no significant associations were found in all genetic models. Interestingly, further analyses stratified by menopausal status in different ethnicities revealed that this polymorphism might provide protective effects against breast cancer risk in postmenopausal Asian women (for dominant model: OR = 0.83, 95 % CI = 0.70-0.97). Sensitivity analyses were performed by sequential removal of individual studies and cumulative statistics have showed combined ORs were not materially altered by any individual study under all comparisons. In summary, this meta-analysis suggests that SHBG Asp327Asn polymorphism is not associated with breast cancer risk overall, while it might be an important genetic susceptibility factor in postmenopausal Asian women for developing breast cancer. Larger and well-designed studies are warranted to confirm our findings in the future.

LncRNA HIF1A-AS2 modulated by HPV16 E6 regulates apoptosis of cervical cancer cells via P53/caspase9/caspase3 axis.

BACKGROUND: Plentiful evidence proves that lncRNAs play a crucial role in tumor development. However, the function and mechanism that were mediated by lncRNA HIF1A-AS2 in cervical cancer remain unclear. METHODS: The lncRNA HIF1A-AS2 was identified via high-throughput microarray analysis of three HPV 16-positive cervical squamous cell carcinoma (CSCC) samples and three HPV-negative normal controls. The expression of HIF1A-AS2 was detected by qRT-PCR in clinical tissues and cancer cells. In vitro and in vivo assays were performed through downregulation or upregulation of HIF1A-AS2. The possible mechanisms of HIF1A-AS2 in cervical cancer cells were explored by western blot, flow cytometric analysis and rescue assays. RESULTS: HIF1A-AS2 was significantly increased in cervical cancer tissue, and in the HPV- positive cervical cancer cells. Further investigation showed that the inhibition of HIF1A-AS2 suppressed cell proliferation, migration, invasion, and induced apoptosis, while up-regulation of HIF1A-AS2 revealed opposite results. In terms of mechanism, we found that HIF1A-AS2 was mediated by HPV16 E6 and regulated cell apoptosis via P53/caspase 9/caspase 3 axis. CONCLUSION: Our findings demonstrate that HIF1A-AS2 functions as a carcinogenic lncRNA that promotes tumor development, and serves as a candidate prognostic factor, which may contribute to the treatment of cervical cancer.

Long noncoding RNA MIR210HG is induced by hypoxia-inducible factor 1α and promotes cervical cancer progression.

Increasing evidence has indicated that long noncoding RNAs (lncRNAs) play essential roles in various types of cancer, especially the ability of tumor cells to adapt to hypoxia conditions. However, only a few of them have been experimentally validated in cervical squamous cell carcinoma (CSCC). In the current study, we identified a hypoxia-induced lncRNA MIR210HG was excessively expressed in CSCC tissues and regulated by human papillomavirus (HPV) type 16 E6 and E7 via hypoxia-inducible factor 1α (HIF-1α). Functional assays revealed the role of MIR210HG in promoting proliferation, migration and invasion of CSCC cells in vitro under normoxia as well as hypoxia conditions. Meanwhile, stable MIR210HG silencing dramatically repressed tumor growth and pulmonary metastasis in vivo. Mechanistically, the depletion of MIR210HG or HIF-1α decreased each other's expression level, while silencing MIR210HG or HIF-1α respectively downregulated the expression levels of phosphoglycerate kinase 1 (PGK1), one of key metabolic enzymes in the glycolysis pathway. Furthermore, decreased expression of PGK1 by HIF-1α knockdown was reversed through the overexpression of MIR210HG. Also, we demonstrated HIF-1α can activate the transcription of MIR210HG via binding its promoter. Taken together, these results expand our understanding of the cancer-associated functions of hypoxia-induced lncRNAs, and highlight MIR210HG forms a feedback loop with HIF-1α contributing to cervical carcinogenesis, with potential implications for therapeutic targeting.

Myo1b promotes tumor progression and angiogenesis by inhibiting autophagic degradation of HIF-1α in colorectal cancer.

Myosin 1b (Myo1b) is an important single-headed membrane-associated motor of class I myosins that participate in many critical physiological and pathological processes. Mounting evidence suggests that the dysregulation of Myo1b expression has been extensively investigated in the development and progression of several tumors. However, the functional mechanism of Myo1b in CRC angiogenesis and autophagy progression remains unclear. Herein, we found that the expression of Myo1b was upregulated in CRC tissues and its high expression was correlated with worse survival. The overexpression of Myo1b promoted the proliferation, migration and invasion of CRC cells. Conversely, silencing of Myo1b suppressed tumor progression both in vitro and in vivo. Further studies indicated that Myo1b inhibited the autophagosome-lysosome fusion and potentiated the VEGF secretion of CRC cells to promote angiogenesis. Mechanistically, Myo1b blocked the autophagic degradation of HIF-1α and then led to the accumulation of HIF-1α, thus enhancing VEGF secretion and then promoting tumor angiogenesis in CRC. Together, our study provided novel insights into the role of Myo1b in CRC progression and revealed that it might be a feasible predictive biomarker and promising therapeutic target for CRC patients.

Myosin 1b promotes migration, invasion and glycolysis in cervical cancer via ERK/HIF-1α pathway.

BACKGROUND: Increasing evidence indicated that metabolic reprograming is essential and has been regarded as a hallmark of cancer. Although the biological functions of Myosin 1b (Myo1b) have been reported in several malignancies, the correlation between Myo1b and cancer metabolism, and its underlying mechanisms remain elusive, particularly in cervical cancer (CC). METHODS: Myo1b and other glycolytic enzymes expression levels were examined in CC cells and tumor tissues from xenograft models by quantitative real-time PCR, Western blot and immunohistochemistry. The biological impacts and regulatory mechanisms of Myo1b on cell migration, invasion and glycolysis were explored. Also, the effects of Myo1b on carcinogenesis and metastasis in nude mice were investigated. RESULTS: Upregulation of Myo1b was found in CC tissues and associated with poor prognosis. Overexpressed Myo1b not only significantly elevated CC cell glycolysis, migration and invasion in vitro, but also promoted tumorigenesis and metastasis in vivo. Conversely, Myo1b knockdown had opposite consequences. Moreover, our study suggested that Myo1b stimulated ERK/HIF-1α pathway and its downstream glycolysis associated genes to modulate the glycolysis, migration and invasion of CC. CONCLUSION: These findings provide evidence that Myo1b regulates migration, invasion and glycolysis in CC through ERK/HIF-1α pathway, suggesting a promising remedial target in treatment of CC.

Human papillomavirus 16 E7 oncoprotein alters the expression profiles of circular RNAs in Caski cells.

Cervical cancer is one of the most common cancer in female worldwide. The expression of high-risk human papillomavirus E7 oncogene is necessary for the maintenance of malignant phenotypes and transformation. Accumulating studies of this protein has been explored in cervical cancer, however, there are fewer studies on how E7 expression affects the expression of global circular RNA. CircRNA, a promising biomarker and even therapeutic target, has become a star molecular in research after miRNA and long non-coding RNA. Our aim of this study was to investigate the global circRNA levels modulated by HPV E7 expression and identified the potential consequences for mechanism studies. Here we investigated the expression profiles of circRNAs by transfecting E7 siRNA in Caski cells with high-throughput microarray technology. In total, we identified 526 dysregulated circRNAs with fold change ≥2 or≤0.5, and p< 0.05. Among them, 352 were up-regulated and 174 were down-regulated. In addition, 8 selected circRNAs confirmed using qRT-PCR was in line with the results of microarray analysis. Furthermore, bioinformatic analyses indicated that differently expressed circRNAs might implicate in the mTOR signaling pathway, proline metabolism and glutathione metabolism. In conclusion, this study showed the expression profiles of circRNAs regulated by HPV16 E7 in cervical cancer cells and provides novel insights into the new potential candidates for future mechanism studies.

Expression of TMEM40 in bladder cancer and its correlation with clinicopathological parameters.

Transmembrane protein 40 (TMEM40) is a 23-kDa protein in cell membrane. There is no report that TMEM40 is associated with cancer. However, our study found that TMEM40 was high expressed in bladder cancer tissues. Immunohistochemical analyses of TMEM40 expression were performed on a tissue microarray including 72 transitional cell carcinomas and 43 normal bladder tissues to investigate the expression and clinical significance of TMEM40 in bladder cancer. We adopted receiver operating characteristic (ROC) analysis to select the optimal cut-off score. TMEM40 expression was defined positive if above 62.5% of cells were stained, and below it was negative. Then, the expression of TMEM40 in bladder cancer cells was evaluated by quantitative real-time PCR and western blot analysis. A significantly high level of TMEM40 in bladder cancer cells was proved. On the basis of ROC curve analysis, TMEM40 expression was positive in 68.1% (n=49) and negative in 31.9% (n=23) of bladder cancer cases. TMEM40 staining was positive in 2.3% (n=1) and negative in 97.7% (n=42) of normal bladder tissues. It showed that TMEM40 was up-regulated in bladder cancer tissues compared to normal bladder tissues. Moreover, TMEM40 expression was significantly associated with histological grade (P<0.05), clinical stage (P<0.05), pT status (P<0.05), but not age. Our study demonstrates that high TMEM40 expression is associated with bladder cancer, and it could be a diagnostic biomarker for bladder cancer.