Ho Y L, Ho S K
Cancer Res. 1981 Feb;41(2):532-6.
The prophage lambda cIts857 induction test with Escherichia coli K12 envA uvrB as the lysogen has been successfully applied to the screening of sparingly water-soluble carcinogens that have been dissolved in dimethyl sulfoxide and metabolically activated with liver enzymes induced either with Aroclor 1254 or phenobarbital. Growth of noninduced lysogenic cells during the test was suppressed with ampicillin, with resultant increase of sensitivity of the test. The maximum inducing activity observed was about 50% of the complete induction level attained with water-soluble carcinogens that did not require metabolic activation. High sensitivity was achieved with the use of the lambda cIts857 prophage strain. In several instances where the Ames Salmonella-microsome test has failed to confirm the carcinogenicity of the respective carcinogens, this induction test has provided a better correlation. Of the carcinogens tested, only one false negative, namely, cyclophosphamide, was encountered. In contrast, the use of the wild-type prophage lambda strain resulted in low sensitivity. The adoption of the endolysin assay technique for the assessment of induction has greatly simplified the procedures and has permitted the screening test to be performed quickly and economically.
以大肠杆菌K12 envA uvrB作为溶原菌的λ噬菌体cIts857诱导试验已成功应用于筛选溶解于二甲基亚砜并经用Aroclor 1254或苯巴比妥诱导的肝酶进行代谢活化的微溶于水的致癌物。试验期间，用氨苄青霉素抑制未诱导的溶原细胞生长，从而提高了试验的灵敏度。观察到的最大诱导活性约为不需要代谢活化的水溶性致癌物所达到的完全诱导水平的50%。使用λcIts857噬菌体菌株实现了高灵敏度。在几例艾姆斯沙门氏菌-微粒体试验未能证实相应致癌物致癌性的情况下，这种诱导试验显示出更好的相关性。在所测试的致癌物中，仅遇到一例假阴性，即环磷酰胺。相比之下，使用野生型λ噬菌体菌株灵敏度较低。采用内溶素测定技术评估诱导作用极大地简化了程序，并使筛选试验能够快速且经济地进行。
