Relationship between E-cadherin and fibroblast growth factor receptor 2b expression in bladder carcinomas

E-cadherin is a cell-cell adhesion molecule expressed predominantly by epit helial cells. Reduction or loss of E-cadherin immunoreactivity has been ass ociated with tumour progression in many epithelial cancers, including bladd er carcinomas. The fibroblast growth factor receptor 2b (FGFR2b) recognized specifically by FGF7 is expressed only by epithelial cells. Recently, decr eased expression of FGFR2b protein and mRNA,vas found to be associated with tumour progression in bladder carcinomas. The purpose of this investigatio n was to look for a possible relationship between E-cadherin and FGFR2b exp ression in bladder carcinomas, As decreased E-cadherin immunoreactivity was found to correlate directly with decreased expression at the mRNA level, t he possible relationship between E-cadherin and FGFR2b was investigated at the mRNA le, el using semi-quantitative RT-PCR in 92 transitional cell carc inomas (TCCs) and four lymph node metastases, All tumours with low E-cadher in expression had low expression of FGFR2b, whereas tumours with low FGFR2b mRNA could express any level of E-cadherin mRNA, The same observation was equally valid for bladder and colon cancer cell lines suggesting that, besi des bladder tumours, this relationship could apply to other carcinomas type s. These results suggest that a relationship exists between the transcripti on of the E-cadherin and FGFR2b genes preventing high expression of FGFR2b where expression of E-cadherin is lon. We suggest that reduced expression o f FGFR2b in conjunction with decreased expression of E-cadherin mag contrib ute to the aggressive behaviour attributable to high grade TCCs.