Olie R A, Looijenga L H, Boerrigter L, Top B, Rodenhuis S, Langeveld A, Mulder M P, Oosterhuis J W
Laboratory of Experimental Patho-Oncology, Dr. Daniel den Hoed Cancer Center, Rotterdam, The Netherlands.
Genes Chromosomes Cancer. 1995 Feb;12(2):110-6. doi: 10.1002/gcc.2870120205.
Recently, conflicting results have been reported on the incidence of RAS mutations in primary testicular germ cell tumors of adults (TGCTs). In four studies a low incidence of mutations (less than 15%) in a variety of TGCTs or derived cell lines was found, whereas in two other studies a high incidence of N- or KRAS mutations (over 40%) was shown. A total of 62 testicular seminomas (SE) and 34 nonseminomatous TGCTs (NS) were studied thus far. The largest series consisted of 42 TGCTs, studied on paraffin embedded tissue. We present the results of analysis for the presence of N- and KRAS mutations, in codons 12, 13, and 61, in snap frozen samples of 100 primary TGCTs, comprising 40 SE and 60 NS. Using the polymerase chain reaction (PCR) and allele specific oligonucleotide hybridization (ASO), mutations were found in five SE (three in NRAS and two in KRAS, all codon 12), and in one NS (KRAS, codon 12). To exclude underestimation of the incidence of RAS mutations in TGCTs due to the presence of an excess of wild type alleles in the analyzed sample, a PCR technique preferentially amplifying KRAS alleles with a mutation in codon 12 was applied to all SE. This approach, allowing a 250 times more sensitive assay, resulted in the detection of only one additional SE with a mutation. Based on a critical analysis of published data and on our results from the largest series of frozen samples investigated thus far, we conclude that N- or KRAS mutations are rare and apparently not essential for initiation or progression of TGCTs.
最近，关于成人原发性睾丸生殖细胞肿瘤（TGCTs）中RAS突变的发生率，已有相互矛盾的报道。在四项研究中，在各种TGCTs或其衍生细胞系中发现了低突变率（低于15%），而在另外两项研究中，显示N-或KRAS突变的发生率较高（超过40%）。到目前为止，共研究了62例睾丸精原细胞瘤（SE）和34例非精原细胞瘤性TGCTs（NS）。最大的一组包括42例TGCTs，是对石蜡包埋组织进行的研究。我们展示了对100例原发性TGCTs的速冻样本中N-和KRAS基因第12、13和61密码子处突变情况的分析结果，其中包括40例SE和60例NS。使用聚合酶链反应（PCR）和等位基因特异性寡核苷酸杂交（ASO），在5例SE中发现了突变（NRAS中有3例，KRAS中有2例，均为第12密码子），在1例NS中发现了突变（KRAS，第12密码子）。为排除由于分析样本中野生型等位基因过多而导致TGCTs中RAS突变发生率被低估的情况，对所有SE应用了一种优先扩增第12密码子处有突变的KRAS等位基因的PCR技术。这种方法能使检测灵敏度提高250倍，结果仅额外检测到1例有突变的SE。基于对已发表数据的批判性分析以及我们对迄今为止研究的最大一组冷冻样本的结果，我们得出结论，N-或KRAS突变很少见，而且显然对于TGCTs的起始或进展并非必不可少。
