EXPRESSION OF THE CD44 CELL-ADHESION MOLECULE IN URINARY-BLADDER TRANSITIONAL-CELL CARCINOMA

CD44 cell adhesion molecule (PgP-1, ECM III, Hermes antigen) is a poly morphic integral membrane glycoprotein associated with cell matrix adh esion, lymphocyte activation, recirculation, and homing, CD44 expressi on has been reported in in malignant lymphoma and in a variety of epit helial human cancers but has not been studied as a prognostic marker i n urinary bladder transitional cell carcinoma. CD44s (standard 85- to 95-kDa macromolecule) expression was measured by qualitative and image analysis-quantitated immunohistochemical techniques using the A3D8 mo noclonal antibody, CD44v6 (a splice variant exon of CD44s) expression was measured by qualitative immunohistochemical techniques using the 2 F10 monoclonal antibody, The results of CD44s and CD44v6 expression we re compared with tumor grade, pathologic stage, and DNA content analys is on Feulgen-stained tissue sections in 44 cases of urinary bladder t ransitional cell carcinoma The mean percentage-positive area of staini ng intensity for CD44s expression in Grade 1 tumors was 61%, compared with 30% for the Grade 3 tumors (P < 0.001), Noninvasive tumors featur ed a 59%-positive area of staining intensity, compared with the 30% st aining percentage for the deeply invasive tumors (P < 0.001), There wa s significant correlation of aneuploid DNA content with loss of CD44s staining (P < 0.05), The staining results for CD44v6 paralleled those for the CD44s, with a significant loss of staining in high-grade and h igh-stage aggressive tumors in comparison with the low-grade nonaggres sive tumors (P < 0.01). In urinary bladder transitional cell carcinoma , CD44s and CD44v6 expression parallels that for other cell adhesion. molecules, such as E-cadherin, that feature a significant progressive loss of immunoreactivity in association with tumor dedifferentiation, advancing pathologic stage, and abnormal DNA content.