应用PCR产物直接银染测序技术检测大肠癌p53基因点突变

Detection of p53 Point Mutation in Colorectal Carcinoma Using PCR-product DNA Silvere Sequencing

应用ＰＣＲ－ＳＳＣＰ结合ＰＣＲ产物直接银染测序技术对２４例大肠癌ｐ５３基因第５～７外显子进行点突变的研究。结果检出５例（２６７％）阳性，均为错义突变；其中３例为碱基ＧＣ到ＡＴ的转换，１例为ＧＣ到ＴＡ的颠换，另１例为ＡＴ到ＣＧ的颠换，后者尚未见报道。突变位点分布在ｐ５３基因第１４１、１７５、２４５、２４８和２５８位密码子，其中４例发生在ＣｐＧ位点。本文对ｐ５３基因点突变谱的分析为大肠癌的病因学研究提供了科学依据，并讨论了ＰＣＲ产物直接银染测序技术的优越性。

Mutations in exon 5～7 of p53 were screened in 24 cases of colorectal carcinoma by a combination of PCR-SSCP and PCR-product DNA silver sequencing. The results showed that all 5(26.7%)cases of point mutations detected were missense mutations, including 3 cases of GC to AT transitions, 1 case of GC to TA transversion and another case of AT to CG transversion. The latter has not been reported before. The mutations occured at codons 141, 175, 245, 248 and 258 respectively, and 4 cases of these five mutations occured at CpG dinucleotides. The analysis of p53 mutation spectra can provide clues to the etiology of colorectal carcinoma. The advantages of DNA silver sequencing are also discussed.