Alterations of microsatellite loci GSN and D18S51 in urinary bladder cancer

Transitional cell carcinoma (TCC) of urinary bladder cancer is the most common malignancy in the urinary system. Genetic instability is an essential property of malignant neoplasms and could be evaluated by microsatellite analysis. Alterations in numerous microsatellite loci are already described in urinary bladder TCC. The aim of this study was to investigate the usefulness of only two microsatellite loci for the detection of bladder TCC, and their correlation with the major clinicopathological parameters.

We analyzed the tissue samples derived from 70 patients with histopathologically confirmed TCC of the urinary bladder, collected by transurethral resection, and samples of normal bladder mucosa derived from 40 patients with nonmalignant diseases. Microsatellite alleles GSN and D18S51 were amplified in paired samples of tissue and leukocyte DNA from each patient, and were analyzed by electrophoresis.

Microsatellite alterations at either GSN or D18S51locus, or in both, were detected in 46 out of the 70 patients (65.71 %) with TCC, but not in the patients of the control group. We found a significant statistical correlation between the frequencies of patients with microsatellite alterations in the examined loci and all three grades of histopathological T-classification. No significant correlation was found regarding the stages or the occurrence of recidivism, metastasis or cancer-related death within the two-year follow-up period.

This study indicates that two selected microsatellite markers could have a potential value in clinical and pathological evaluation of urinary bladder TCC, especially regarding the prediction of tumor differentiation. Additional studies and further validation of the method are needed. Hippokratia 2015; 19 (3): 200-204.