LOSS OF HUMAN E-CADHERIN (ECD) CORRELATED WITH INVASIVENESS OF TRANSITIONAL-CELL CANCER IN THE RENAL PELVIS, URETER AND URINARY-BLADDER

Loss or decreased expression of E-cadherin (ECD), which forms an epith elial junction complex that includes several other proteins and trigge rs signal transduction, may contribute to tumor progression. In the pr esent study, we examined 90 transitional cell cancers (TCCs), 47 urina ry bladder cancers and 43 ureteral or renal pelvic cancers, as well as TCC and papilloma cell lines to determine whether they express ECD. W e classified ECD expression into normo-expression (like normal epithel ial), decreased and loss of ECD staining on TCCs (urinary bladder, ren al pelvic or ureteral). We found that low-stage TCCs expressed normal ECD in 68%, decreased of ECD in 20% and loss of ECD in 12%, whereas hi gh-stage TCCs expressed 29%, 41% and 30% of ECD staining, respectively (P < 0.01). Furthermore, grade 1 TCCs were all estimated to show norm o-expression, grade 2 TCCs expressed normal ECD in 49%, decreased of E CD in 41% and loss of ECD in 10% grade 3 TCCs classified as 20%, 30% a nd 50%, respectively (P < 0.01). Staining for cultured cell lines show ed positive membranous staining for ECD in a benign papilloma cell lin e, RT4 and a TCC cell line, HT1376, but not in a TCC cell line, T24. R everse-transcription polymerase chain reaction showed the presence of ECD and alpha-catenin mRNA in RT4 and HT1376, and only alpha-catenin i n T24. Thus, it is more likely that decrease or loss of ECD might cont ribute to the malignant character of tumor cells and result in tumor p rogression.