20690

Expression of Survivin and Its Spliced Variants in Bladder Tumors as a Potential Prognostic Marker.

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Introduction: Survivin, a novel inhibitor of apoptosis, is re-expressed in a vast majority of human cancers and is widely considered as a diagnostic marker of cancers. Survivin protein regulates both cell division and apoptosis. There are at least 5 spliced variants of the gene with different subcellular localization and anti-apoptotic property. We examined the expression pattern of survivin and its 2 spliced variants, survivin-(delta)Ex3 and survivin-2B, and their prognostic values in archival collections of formalin-fixed paraffin-embedded samples of bladder tumors. Materials and Methods: Total RNA from formalin-fixed paraffinembedded samples (51 samples from 30 patients with bladder cancer and 5-year follow-up) were extracted and analyzed by semiquantitative reverse transcriptase polymerase chain reaction technique. Tissue distribution and subcellular localization of survivin protein in tumor tissues was also examined by immunohistochemistry. Results: The expression of survivin, survivin-(delta)Ex3, and survivin-2B were detected in 66.6%, 47.8%, and 54.7% of the specimens, respectively. The expression of survivin and survivin-(delta)Ex3 were preferentially elevated in tumors with higher grades, whereas survivin-2B expression was lower in highgrade tumors (P = .04). A reverse correlation was observed between survivin-2B expression and high-grade tumors. Immunohistochemistry results also confirmed the nuclear localization of survivin protein within tumoral cells. Conclusion: We were successful in detecting the expression of survivin and its variants in formalin-fixed paraffin-embedded bladder samples. Furthermore, our results showed that overexpression of survivin and survivin-(delta)Ex3 in bladder tumors correlates with poor prognosis of bladder cancer. We suggest that survivin and its variants are suitable prognostic markers of bladder tumors.

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