Cigarette smoking-related OLC1 overexpression associated with poor prognosis in bladder urothelial carcinoma

To explore the clinical significance of OLC1 and cigarette smoking in bladder urothelial carcinoma (UBC). OLC1 mRNA expression was detected in 106 UBC samples by mRNA array or reverse real-time PCR. OLC1 protein expression in 114 UBC samples was detected by immunohistochemical staining. Wild-type C57BL/6J mice were injected with cigarette smoke condensate (n = 12) or exposed to cigarette smoke (n = 6) to investigate the correlations between cigarette smoking and OLC1 expression using mRNA array. The mRNA and protein expression of OLC1 were higher in tumor samples (p < 0.01) and significantly correlated with tumor stage (p < 0.05). OLC1 protein expression and smoking history were correlated with disease-free survival (p < 0.05). OLC1 expression was significantly elevated in smoking patients with higher smoking intensity on both mRNA and protein levels (p < 0.05). Cigarette smoke exposure experiments revealed that OLC1 mRNA overexpressed in bladder uroepithelium of mice. OLC1 could serve as a potential prognosis biomarker of UBC, especially for smoking patients.