Schistosoma hematobium soluble egg antigens induce proliferation of urothelial and endothelial cells

Bladder carcinoma accounts for 26% of reported human malignancies in Egypt, and has been strongly associated with urinary schistosomiasis. Nevertheles s, the immediate role of schistosomal egg proteins in bladder carcinogenesi s is unexplored. We investigated the effects of crude soluble egg antigens (SEA) of Schistosoma hematobium on urothelial cell proliferation, The proli feration of bovine endothelial Endo, human urothelial J82 and smooth muscle SMC cell lines was assessed by low-density growth assays. SEA induced prol iferation of both J82 and Endo cells in a dose-dependent fashion, but not S MC. Preboiling or proteinase K treatment of SEA abolished its effect. In ad dition, SEA enhanced urothelial expression of B-cell translocation protein (BTG1) and human proliferating cell nuclear antigen (PCNA) mRNAs. Given the strong correlation between cell proliferation and carcinogenesis, the find ings suggest that crude SEA may play some role in schistosomal bladder carc inogenesis.