Prophylactic efficacy of BCG and polyinosinic : Polycytidylic acid on implanted murine bladder tumor

Kim, Hyeon Hoe; Lee, Eun Sik; Lee, Chong Wook

Abstract

A study was done to evaluate whether intraperitoneal Polyinosinic: Polycytidylic acid (Poly I:C) administration in addition to BCG could enhance the anticancer effect of BCG on subcutaneously implanted syngeneic murine bladder tumor. The appropriate administration schedules of Poly I:C and BCG were defined by evaluating the change of natural killer cell activity and cell mediated cytotoxic effect against syngeneic bladder tumor cells or splenic and peritoneal lymphocyte at regular time interval. The prophylactic anticancer effect of Poly I:C alone and Poly I:C plus BCG were evaluated by observing the tumor take rate and growth change of the taken tumor compared to the control group. Bladder tumor take rate and growth of the taken tumor were suppressed after administration of Poly I:C alone. Natural killer cell activity of the splenic and peritoneal lymphocytes were enhanced and in vitro cytotoxicity against MBT-2 was increased after Poly I:C administration. When Poly I:C was administrated in addition to BCG, tumor take rate and tumor growth were more suppressed and the time for appearance of the visible tumor was prolonged compared to BCG therapy alone. In conclusion, Poly I:C showed prophylactic anticancer effect against subcutaneously implanted murine bladder tumor when used alone or in combination with BCG, and the cell mediated cytotoxicity including enhanced NK cell activity seemed to play an important role in their anticancer effect. These results suggest a possibility of Poly I:C, alone or in combination with BCG, would become a new prophylactic treatment modality against bladder tumors.