Objective:To study the expression of nanog in human bladder cancer tissue

and demonstrate its significance in bladder cancer formation and relationship with bladder cancer stem cells.Methods:The expression of nanog was examined in the pathological specimens from 32 cases of bladder cancers

15 apparently nontumor tissues taken from the margin of tumors and 10 normal urothelial tissues by using semiquantitative RT-PCR and immunohistochemistry respectively.Results:The expression rate of nanog in bladder cancers was 84.38%(27/32)but at much lower level(P<0.001)in some nonneoplastic samples(5/32)

According to immunohistochemical (IHC)results

nanog is primarily localized in the nuclei of tumor cells

with no or lowimmunoreactivity in nontumor cells.the positive rate and intensity of the nanog expression had no obvious relationship with the grade

recurrence or metastasis of bladder cancer(P>0.05). Conclusion:The expression of nanog showed there might exist bladder cancer stern cells.This has significant aplications to uncover the existence of CSC and to isolate and identificate bladder cancer stem cells.The rate and level of nanog expression in bladder cancer showed there might exist significant correlation between embryonic gene and occurrence and development of tumor.