The Effects of Intravesical BCG Instillation on Bladder Cancer Induced by N-butyl-N-(4-hydroxybutyl) Nitrosamine

Song, Hee Cheol; Kim, Sang Woo; Rim, Joung Sik

Abstract

PURPOSE: We investigate the effects of intravesical BCG therapy on the occurance of superficial bladder cancer induced by N-butyl-N-(4-hydroxybutyl) nitrosamine(BBN) in Fisher 344 rats in vivo. We also examine whether NO mediated the antitumor activity of BCG against superficial bladder cancer in Fisher 344 rats.
MATERIALS AND METHODS
BBN(0.1%) is orally administered for 20 weeks and it is combined with BCG(0.27mg) or NG-monomethyl-L-arginine (NG MMA, 10mg). once every week from 8th week to 19th week. The rats are sacrified at 20th week. NO secretion in urine for 24 ours is significantly increased in the BCG treated rats compared to the animals treated with saline or NGMMA.
RESULTS
Pathologic findings demonstrate that the incidence of carcinoma is not statistically different in saline, BCG, NGMMA(p>0.05). However the size and number of tumor is decreased in the BCG treated rats compared with saline or NGMMA treated rats bearing bladder cancer induced by BBN(p<0.05). Inducible NO synthase(iNOS) is strongly induced in bladder tissue of rats treated with BCG and NGMMA but not in saline.
CONCLUSIONS
Intravesical instillation of BCG on bladder cancer induced by BBN does not decrease the cancer occurrence but reduces the number and size of bladder cancer. Our results suggest that nitric oxide induced by intravesical instillation of BCG may mediate antitumor activity against the occupance of superficial bladder cancer.