Michelin S, Daya-Grosjean L, Sureau F, Saïd S, Sarasin A, Suárez H G
Laboratoire de Génétique Moléculaire (UPR 42, CNRS), Institut de Recherches Scientifiques sur le Cancer, Villejuif, France.
Oncogene. 1993 Jul;8(7):1983-91.
Human xeroderma pigmentosum (XP) fibroblasts were transformed with N-methyl-N'-nitro-N-nitrosoguanidine (MNNG). The transformed cells, called ASKMN, were immortalized, grew in agar and were tumorigenic in nude mice. A trp-met oncogene was identified in ASKMN cells, after transfection of high molecular weight DNA on 3T3 mouse cells. The ASKMN cells and the 3T3 transformants expressed the 5-kb mRNA transcribed by the tpr-met oncogene and its p65tpr-met phosphorylated protein. Using the polymerase chain reaction (PCR) technique followed by hybridization with synthetic probes or direct sequencing, we showed that the sequence encompassing the 'rearranged breakpoint' was the same as that previously described in the tpr-met oncogene present in the MNNG-HOS cells. However, G to A transitions found in the tpr or met sequences of the ASKMN oncogene, probably the result of the specific mutagenic activity of MNNG, were absent in the MNNG-HOS gene. Apparently normal chromosomes 1 and 7 were identified in the ASKMN cell metaphases using several cytogenetic techniques.
用人的着色性干皮病（XP）成纤维细胞经N-甲基-N'-硝基-N-亚硝基胍（MNNG）转化。转化后的细胞称为ASKMN，具有永生化特性，能在琼脂中生长且在裸鼠中具有致瘤性。在将高分子量DNA转染到3T3小鼠细胞后，在ASKMN细胞中鉴定出一个色氨酸-甲硫氨酸癌基因。ASKMN细胞和3T3转化细胞表达由tpr-met癌基因转录的5kb mRNA及其p65tpr-met磷酸化蛋白。通过聚合酶链反应（PCR）技术，随后与合成探针杂交或直接测序，我们发现包含“重排断点”的序列与先前在MNNG-HOS细胞中存在的tpr-met癌基因中描述的序列相同。然而，在ASKMN癌基因的tpr或met序列中发现的G到A的转变，可能是MNNG特异性诱变活性的结果，在MNNG-HOS基因中不存在。使用几种细胞遗传学技术在ASKMN细胞中期鉴定出明显正常的1号和7号染色体。
