DMBA유도 Hamster 협낭점막 상피암에서의 Bleomycin 및 BCG의 효과

The effects of bleomycin and BCG on squamous cell carcinoma induced by DMBA in hamster

The purpose of this experimental study was to observed the effect of bleomycin and BCG on the DMBA induced buccal pouch carcinoma in hamster. 48 Golden Syrian hamsters weighing about 100 grams were used. Buccal pouch carcinoma was induced by the application of 0.5% DMBA in heavy mineral oil, 3 times per week for 12 weeks. Experimental animals were divided into control group and three experimental groups, Group Ⅰ: Administered bleomycin 5㎎/㎏ intraperitoneally. Group Ⅱ: Administered BCG 1㎎ in 0.5㎖ sterile water suspension of the back intradermally. Group Ⅲ: Administered bleomycin and BCG as above mentioned dosage and routes. The animals were sacrificed on the 14, 15, 16, 17th week serially and the tumor massess were examined grossly and then prepared for light microscopic and electromicroscopic examination. The results were as follows: Grossly, papillomatous masses were noted at 12 weeks after topical application of DMBA in all experimental animals which were continuously increased in size upto the end of experiment in control but that was not remarkable in experimental groups. Characteristically the erosion or ulcerative necrosis was more prominent in experimental groups than in control from 16th week. Histologically, the growth pattern of experimentally induced squamous cell carcinoma was relatively similar in all groups except for somewhat infiltrative in growth of control. And desquamation of surface atypical squamous cells was more prominent with microcystic formation in invading projections of tumor cells in experimental groups. The number of mitosis was continuously increased until 3 weeks after injection of bleomycin with/or BCG but that was decreased at 4 weeks after admistration of regimes while the mitosis was easily seen and progressively increased in number upto the end of experiment in control. Ultrastructurally, there was no remarkable difference in morphology of early phase of tumor cells between control and experimental groups. However, the peripheral clumping of chromatin in nucleus with fade away of nucleoli was more prominent in experimental groups than in control with lapse of time. The separation of tumor cells was progressively more prominent in experimental groups without remarkable differences in each groups by continuous loss of microvilli and desmosomes with simpling of cytoplasmic organellae. The above findings suggest that the therapeutic effect occurs at least from 3 weeks after administration and that there is no remarkable difference in their efficacy.