BUB1 drives the occurrence and development of bladder cancer by mediating the STAT3 signaling pathway.

BACKGROUND: The incidence of bladder urothelial carcinoma (UC), a common malignancy of the urinary tract, is approximately three times higher in men than in women. High expression of the mitotic kinase BUB1 is associated with the occurrence and development of several cancers, although the relationship between BUB1 and bladder tumorigenesis remains unclear. METHODS: Using a microarray approach, we found increased BUB1 expression in human BCa. The association between BUB1 and STAT3 phosphorylation was determined through molecular and cell biological methods. We evaluated the impact of pharmacologic inhibition of BUB1 kinase activity on proliferation and BCa progression in vitro and in vivo. RESULTS: In this study, we found that BUB1 expression was increased in human bladder cancer (BCa). We further identified through a series of molecular and cell biological approaches that BUB1 interacted directly with STAT3 and mediated the phosphorylation of STAT3 at Ser727. In addition, the findings that pharmacologic inhibition of BUB1 kinase activity significantly suppressed BCa cell proliferation and the progression of bladder cancer in vitro and in vivo were further verified. Finally, we found that the BUB1/STAT3 complex promoted the transcription of STAT3 target genes and that depletion of BUB1 and mutation of the BUB1 kinase domain abrogated this transcriptional activity, further highlighting the critical role of kinase activity in the activation of STAT3 target genes. A pharmacological inhibitor of BUB1 (2OH-BNPP1) was able to significantly inhibit the growth of BCa cell xenografts. CONCLUSION: This study showed that the BUB1 kinase drives the progression and proliferation of BCa by regulating the transcriptional activation of STAT3 signaling and may be an attractive candidate for therapeutic targeting in BCa.

Small cell carcinoma of the upper urinary tract and factors associated with progress survival: a systematic review and pooled analysis.

INTRODUCTION: Little is known about small cell carcinoma of the upper urinary tract (UUT-SCC), the aim of this study is to identify the risk factors in relation to survival of patients with UUT-SCC. EVIDENCE ACQUISITION: Literature search on UUT-SCC was performed in databases including MEDLINE, EMBASE, Wangfang, and CNKI. Studies were eligible for inclusion if outcomes of patients with histopathologically confirmed UUT-SCC were reported. The relevant data on clinic, pathology, and therapy were collected. Progress survival was evaluated using the Cox regression model with the robust sandwich estimates of the covariance matrix. EVIDENCE SYNTHESIS: There were 55 eligible publications identified, contributing 76 patients in total. The median of overall survival (OS) was 14 months. In univariable analyses, pathological stage and platinum-based chemotherapy regimen were associated with OS (pT3-pT4 versus pT1-pT2, HR=3.228, P=0.005; other chemotherapies versus platinum-based, HR=6.249, P=0.035). The median of cancer-specific survival (CSS) was 15 months. In univariable analyses, pathological stage and platinum-based chemotherapy regimen were associated with CCS (pT3-pT4 versus pT1-pT2, HR=3.332, P=0.004; non-platinum based versus platinum-based, HR=7.784, P=0.025). CONCLUSIONS: In multivariable analyses, no variables were associated with OS and CSS. UUT-SCC is a rare tumor characterized by an aggressive clinical course. Pathological stage and platinum-based chemotherapy regimen are the most important factors related to OS and CSS.

Protein kinase TTK promotes proliferation and migration and mediates epithelial-mesenchymal transition in human bladder cancer cells.

AIM: To investigate the expression level of TTK in bladder cancer, and its role in the proliferation and migration. To investigate the relationship between TTK and epithelial-mesenchymal transition (EMT). PATIENTS AND METHODS: We compared the expression level of TTK between human bladder cancer tissues and normal bladder epithelial tissues from 70 patients using immunohistochemistry, qRT-PCR and western blotting. Subsequently, we conducted cell viability and cell migration experiments to investigate the effect of TTK on bladder cancer cells. Furthermore, we used qRT-PCR to detect the biomarkers of EMT to examine the relationship between TTK and EMT. RESULTS: The expression level of TTK was significantly higher in bladder cancer tissues as compared to the adjacent noncancerous tissues (P < 0.001). The qRT-PCR, immunohistochemistry, and western blotting also showed the same trend. Furthermore, cell viability and cell migration assays showed that TTK promoted proliferation and migration of human bladder cancer cells, and mediated EMT. CONCLUSION: This study showed that high expression of TTK can promote proliferation and migration, and might mediate the EMT process in human bladder cancer cells.