• 作者： 林仁混; 張慧貞
• 作者服務機構： 國立臺灣大學醫學院生化學科暨行政院國科會癌症研究推動小組
• 中文摘要： 由最近的研究顯示，很多化學致癌物在生體中經過細胞??的活化作用之後，可與DNA結
  合而改變其基因的功能，因而表現其突變作用。有些研究者因而推想可從化合物之突變作用來篩
  試其致癌作用。目前一些原核細胞如大腸菌、沙門菌等都被應用來作為突變物質之篩試系統。甚
  至有人主張可用這些細胞來飾試環境致癌物。由於真核細胞的致癌作用是相當複雜的病理變化，
  用原核細胞能否正確的篩試，引起各方面很多的爭論。
  本研究利用Sarcina lutea之顏色突變來篩試常見的致癌物如Aflatoxin B1, Benzo(a)pyrene,
  4-Nitroquinoline-N-oxide, N, N-Dimethylnitrosamine, N, N-Diethylnitrosamine, N-Methyl-
  N'-nitro-N-nitrosoguanidine等。結果發現這一些致癌物引起顏色突變能力與其致癌力並無平
  行的關係。溯查文獻並發現許多致癌物在原核細胞之突變力與其在動物之致癌力並無量的關連。
  本研究也發現一些化學致癌物之突變作用，在紫外光之影響下有很大的促進作用。因此推論太陽
  光中之紫外線可能影響到一些環境致癌物在生物體中之作用。y
• 英文摘要： Recent studies in experimental oncologyhave been demonstrated that biotransformationof chemical carcinogens by metabolic activationin vivo leads to the production of electrophilicreactants which then interact with the nucleo-philic sites in the cellular DNA, RNA orprotein. The consequence of these interactionsmay result in cellular neoplastic transformationand mutation. It is suggested that the mu-tagenicity of a compound may reflect itscarcinogenicity; furthermore, many microbialsystems such as E. coli, Salmonella typhi-murium, yeast, etc., have been used as testerorganisms for screening the carcinogenic com-pounds in human environments. As is well-known, carcinogenesis is a very complicatedprocess of pathological change induced ineucaryotic cells, it is doubtful that mutagenicityassessed by a procaryotic system can extrapolateintimately to the carcinogenicity in higherorganism. In the present study, color mutants ofSarcina lutea have been used as a tester organis nin screening the mutagenicities of aflatoxin Bl,benzo(a)pyrene, N,N-dimethylnitrosamine, N,N-diethylnitrosamine, N-methyl-N'-nitro-N-nitrosoguanidine, and 4-nitroquinoline-N-oxide.The results indicated that the wild type ofSarcina lutea (bright yellow) was converted bycertain carcinogen such as MNNG to white,red, pale yellow color mutants; color mutationinduced by these chemical carcinogens were notcorrelated with their carcinogenicities. Manystudies cited in the literature also showed thatthe mutagenicities of chemicals were notquantitatively associated with their carcinogenic-ities. The mutagenicities of MNNG and NQOwere found to be potentiated by uv radiation.These results suggested that uv in the solarlight might play a significant role in the actionof some environmental carcinogens.
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