Bacillus Calmette-Guerin and BCG cell wall skeleton suppressed viability of bladder cancer cells in vitro.

AIM: Bacillus Calmette-Guerin (BCG) is one of therapeutic options for urothelial carcinoma (UC). The objectives of this study were to determine the direct effect of viable or heat-killed BCG and BCG cell wall skeleton (BCG-CWS) on UC cells in vitro.

MATERIALS AND METHODS: UC cell lines were co-cultured with viable or heat-killed BCG Immunobladder® (Tokyo 172 strain) and BCG-CWS. Viability of the cells, apoptosis and BrdU incorporation were estimated.

RESULTS: BCG induced cell growth retardation in highly malignant UC bearing integrin α5β1 (VLA5). VLA5-blocking antibody partially abrogated this effect. BCG treatment induced a modest increase in the sub-G(1) fraction of cells and a decrease of BrdU incorporation. Cell growth retardation effect of viable BCG was reproduced by both heat-killed BCG and BCG-CWS.

CONCLUSION: The results indicate that VLA5 may be a biomarker of UC with sensitivity to BCG. Moreover, BCG-CWS is a promising substance which might replace BCG, preventing life-threatening complications of viable BCG treatment.