ALDH1 positive cell population is correlated with poor prognosis in Bladder Transitional Cell Carcinomas

Background:The aim of present study is to evaluate the expression and clinical significance of putativecancer stem cell markers, CD44 and ALDH1, in a series of Bladder Transitional CellCarcinoma (TCC) included in tissue microarray (TMA).Materials and Method:One hundred seventy three bladder tumors including 107(62%) high grade and 66 (38%) lowgrade were immunohistochemically examined for the expression of CD44 and ALDH1. Thecorrelation of expression of these markers with clinicopathological parameters was alsoassessed.Results:High level of expression of ALDH1A1 was found in 16% (25 of 161) of bladdercancerswhich was significantly correlated with advanced pathologic stage, high histologicgrade, increased rate of recurrence, lamina propria involvement and vascular invasion. (all P< 0.05). High level of CD44 expression was found in 58% (95 of 164) of cases, which waspositively correlatedwith histologic grade.Conclusion:The existence of ALDH1A1+ cells in a fraction of the CD44+ tumor cell populationindicated that although CD44+ population comprised CSCs of bladder cancers, a subset ofthe population with ALDH1A1 marker had CSC characteristics. Therefore, ALDH1A1 alongwith CD44apply as a useful ALDH1 positive cell population is correlated with poorprognosis in Bladder Transitional Cell Carcinomas marker for isolating CSCs from bladdertumours and monitoring the tumourprogression in patients with poor prognosis. Indeed, it canserve as a novel therapeutic agent for targeted therapy of the bladder cancer.