ANTI-TUMOR EFFECT OF NANO-PARTICULATED BACILLUS CALMETTE- GUERIN (BCG) CELL WALL COMPLEX ON BLADDER CANCER CELL LINE

1) Abstract　Bacillus Calmette‑Guerin (BCG) has been widely accepted as an eff ective treatment for CIS and superfi cial carcinoma of the bladder. However it has considerable side eff ects and toxicity. We thought if eff ective bacterial cell wall elements as substitutes for live bacteria were identifi ed useful treatment with lower toxicity while maintaining strong anti‑tumor eff ects might be possible. For these reasons we generated a nano‑particulated BCG complex which does not contain live bacteria. Here we present its direct in vitro anti‑tumor eff ect on bladder cancer cell lines. Tokyo 172 BCG sub‑strain was disrupted by French press with monitoring the particle distribution by the particle analyzer. After removing the not‑disrupted bacteria by centrifuge at 6800×g supernatant was centrifuged at 18000�g. Then the supernatant (Sup) and the precipitate (CW) were lyophilyzed to obtain nano‑particulated BCG complex. Bladder cancer cell lines J82 and KK47 were co‑cultured with BCG Sup CW or Sup+CW (mix) for 5 days then viable cell numbers were counted. In J82 cells when separately added to the culture medium both CW and Sup reduced cell number to about 70% of control cells. While they were mixed together they reduced cell number equally compared with BCG; 59.2% (mix) vs 60.2% (BCG) in J82 cells 67.3% vs 68.8% in KK47 cells. These preliminary in vitro experiments demonstrated the identical direct anti‑tumor eff ect of nano‑particulated BCG to that of live BCG. In vivo tumor assays are warranted for clinical application of nano‑particulated BCG. Hirosaki Med.J.　59 Supplement:S162―S166,2007