Cancer stem cells (CSCs) are thought to be crucial for understanding the
biological roots of
cancer, and are of increasing importance as a target for new
anticancer agents. According to an expression analysis of the
cell surface antigens of various types of
cancer, CD133 is considered to be a potential marker of
cancer stemness. In this study, a human
urinary bladder cancer cell line (J82) was used to analyze the cancer stem cell-like characteristics of CD133+
bladder cancer cells in vitro and in vivo. The CD133 expression in the J82 cells was examined and the cells were immunomagnetically categorized into positive and negative subsets. The CD133- and CD133+ subsets were phenotypically divergent with regard to the cell growth pattern, while CD133+ cells tended to colonize during their growth. In CD133+ cells, the pluripotent stem cell factors Oct-4 and Sox-2 were upregulated, and a statistically significant proliferation increase was observed when compared to CD133- cells. The CD133+ subpopulation was more tolerant to the chemotherapeutic agent
cisplatin, and Bacillus Calmette-Guérin (BCG), an agent instilled intravesically to treat
bladder cancer. In addition, CD133+ J82 cells were more resistant to
radiation treatment when compared to CD133- cells. The in vivo
tumorigenesis of the CD133- and CD133+ subsets of J82
cancer cells was also examined by subcutaneously injecting them into nude mice. The
tumor growth was more aggressive in the CD133+ subpopulation, showing a significant difference in the tumorigenic potential in these subsets. In conclusion, J82 human
bladder cancer cells include CD133- and CD133+ subpopulations, while the CD133 molecule is a potential marker of the potential
malignancy of human
bladder cancer. In the present study, the CD133+ subpopulation was herein demonstrated to have certain characteristics consistent with those of cancer stem cells.