Introduction: Normal-looking mucosa may harbor genetic changes preceding a visible tumor. This study was aimed at exploring the role of the quantitative expression of micro-RNAs (miRNAs) in bladder cancer tissue in comparison with normal mucosa and healthy controls (HCs) as a molecular marker.
Materials and methods: Between October 2011 to December 2012, tissue from the bladder tumor of 21 patients (cases tumor, CT), normal mucosa (case control, CC) of the same patients (n-21) and normal bladder mucosa from 10 HCs were obtained. miRNAs of angiogenesis, endothelial mesenchymal transition and apoptosis were quantified using stem-loop RT Taq Man polymerase chain reaction. Statistical analysis was performed using the Chi square and independent sample T tests by using SPSS version 16.
Results: The mean age of the patients and controls were 55.41 ± 11.03 and 52.14 ± 13.04 years. miR-21, miR-205, miR-126, miR-10b and miR-200a were highly expressed in CT (P < 0.027, <0.048, <0.025, <0.029 and < 0.005) as compared with HC. Expression of miR-21 and miR-129 were both correlated with grade and stage (P = 0.001 and < 0.009, respectively) and the level of expression was different in the same grade of non-muscle invasive tumors. The fold change of miR129, miR205 and miR200a was significantly higher in the normal-looking mucosa of bladder tumor patients than the HC (P < 0.005).
Conclusion: Expression of miR129, miR205 and miR200a in the normal-looking mucosa of bladder cancer patients was significantly higher than the normal mucosa of a HC. This may help in predicting recurrence and formulating the follow-up strategy.
Keywords: Bladder cancer; micro-RNA; muscle invasive; non-muscle invasive.