Objective      To determine the expression and clinic significance of recepteur d’origine naetais ( RON ) and claudin-4 in bladder transitional cell carcinoma (TCCB) and investigate their possible role in progression and invasion of TCCB.       Methods      A total of 36 patients with pathological identified TCCB undergoing radical cystectomy in our department during March 2010 to May 2011 were recruited in this study. Their clinical data including pathological grades

clinical stages

single and multiple foci

primary and recurrence tumor were collected. The expression of RON and claudin-4 in the tissue samples of 16 normal bladder tissues and these 36 TCCB were tested by Western blotting and reverse transcription polymerase chain reaction (RT-PCR) at protein and mRNA levels

respectively. The relationships between RON and claudin-4 with pathological grades

clinical stages

sex

age

single and multiple foci

primary and recurrence tumor were also analyzed.       Results      The expression of RON in TCCB was significantly higher than in normal bladder tissues (P=0.000)

and significant differences were found in low-grade and high grade differentiation

and in non-muscle invasion and muscle-invasive tumors (P=0.003

P=0.000)

but not in different sex

age

primary and recurrence tumor

and single and multiple foci (P0.05). The expression of claudin-4 in TCCB was significantly higher than in normal bladder tissues (P=0.003)

and significant difference  was found between non-muscle invasion and muscle-invasive tumors (P=0.018)

but not in low-grade and high grade differentiation

sex

age

primary and recurrence tumor

and single and multiple foci (P0.05). Both the protein and mRNA levels of RON and claudin-4 were higher in TCCB than those in normal bladder tissues

and were positively correlated (r=0.560

P0.05).       Conclusion      RON and Claudin-4 are up-regulated and positively correlated in TCCB

indicating that they may exert a positive regulatory effect on the progression and invasion.