Strong expression of CD133 is associated with increased cholangiocarcinoma progression

AIM: To determine the role of CD133 in cholangiocarcinoma progression. METHODS: CD133 protein expression was evaluated by immunohistochemistry in 34 cholangiocarcinoma specimens. In addition, proliferation, chemoresistance and invasive properties of CD133-enriched (CD133+) and CD133-depleted (CD133-) RMCCA1 cholangiocarcinoma cells were studied and compared. RESULTS: Strong CD133 expression was observed in 67.6% (23/34) of the cholangiocarcinoma specimens. Strong expression of CD133 was significantly associated with nodal metastasis (P = 0.009) and positive surgical margin status (P = 0.011). In the in vitro study, both the CD133+ and CD133- cells had similar proliferation abilities and resistance to chemotherapeutic drugs. However, the CD133+ cells had a higher invasive ability compared with CD133- cells. CONCLUSION: CD133+ cells play an important role in the invasiveness of cholangiocarcinoma. Targeting of the CD133+ cells may be a useful approach to improve treatment against cholangiocarcinoma.