(HealthDay News)  – Four microRNAs (miRNAs) are differentially expressed in low-grade noninvasive (pTa) and high-grade invasive (pT2-3) urothelial carcinoma, and show potential as diagnostic or prognostic markers.

Nelson Dip, from the University of São Paulo Medical School in Brazil, and colleagues examined expression of 14 miRNAs in urothelial carcinoma. Quantitative reverse transcriptase-polymerase chain reaction was performed on surgical specimens from 30 patients with low-grade pTa and 30 with high-grade pT2-3 urothelial carcinoma, and expression was compared with normal bladder tissue from five patients who underwent surgery for benign prostatic hyperplasia.

The researchers found that, in 100% of low-grade pTa specimens, miR-100 was significantly underexpressed, while miR-10a was significantly overexpressed in 73.3%. In high-grade pT2-3 disease, miR-21 and miR-205 were significantly overexpressed. Expression of other miRNAs was similar to that of normal bladder tissue or was underexpressed in each tumor group. For patients with low-grade pTa urothelial carcinoma, miR-21 over expression correlated with shorter disease-free survival. For patients with high-grade pT2-3 urothelial carcinoma, increased miR-10a levels correlated with shorter disease-free and disease-specific survival.

“Low-grade pTa and high-grade pT2-3 urothelial carcinomas show differences with respect to miRNA expression that could be incorporated into the well-known carcinogenic pathway,” the authors write. “Aberrant miRNA levels could be used as new biomarkers to better treat patients with bladder cancer or those susceptible to the neoplasm.”

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