Prevention of human bladder tumor cell implantation in an in vitro assay.

The high recurrence rate of bladder tumors can be reduced by prevention of tumor cell reimplantation on denuded urothelium following transurethral resection. This can be achieved by intravesical chemotherapy immediately after the resection of the bladder tumors. We have demonstrated, in an in-vitro system, the process of human bladder tumor cell implantation on a naturally produced extracellular matrix (ECM) which simulates the exposed bladder basement membrane and submucosa. Using this model we examined the efficacy of various cytotoxic agents in preventing tumor cell adhesion to the ECM. Human bladder tumor cell implantation was prevented following exposure of the cells to distilled water, epodyl or mitomycin C, and significantly reduced following one hour incubation in cisplatinum and doxorubicin. The maximal effect for each of these cytotoxic agents was reached within 30 to 60 minutes of treatment. Mitomycin C reached maximal effect within 10 minutes. In contrast, thiotepa did not cause a significant reduction in cell adherence to ECM as compared to untreated control cells.