人肝细胞癌中PTEN基因的DNA杂交及突变分析

目的　研究人肝细胞癌中ＰＴＥＮ基因缺失及第５、第８外显子突变。方法　应用Ｓｏｕｔｈｅｒｎ杂交检测人肝细胞癌中ＰＴＥＮ基因限制性片段长度多态性和纯合性缺失、半合性缺失、片段缺失。应用聚合酶链单链构象多态性（ＰＣＲＳＳＣＰ）检查ＰＴＥＮ基因的第５、第８外显子的突变。结果　Ｓｏｕｔｈｅｒｎ杂交结果显示，所有３４例肝细胞癌中ＰＴＥＮ基因未见限制性片段长度多态性或纯合性缺失、半合性缺失、片段缺失。ＰＣＲＳＳＣＰ检测发现，２例肝细胞癌第５外显子ＰＣＲ产物均显示１条额外电泳迁移带，突变率为５．９％（２／３４）。另２例肝细胞癌第８外显子ＰＣＲ产物呈现额外电泳迁移带，突变率为５．９％（２／３４），合计突变率为１１．８％（４／３４）。结论　所检３４例人肝细胞癌中ＰＴＥＮ基因未见纯合性缺失、半合性缺失、片段缺失，但存在突变。

DNA Blotting and SSCP Screening of the PTEN Gene in Human Hepatocellular Carcinoma

Purpose To determine the mutations of exon 5 and exon 8 and deletions of the PTEN gene in human hepatocellular carcinoma(HCC). Methods Southern blotting was performed in HCC DNA samples to assess restriction fragment length polymorphism (RFLP) and homozygous, hemizygous, large fragment deletions of PTEN .Exon 5 and exon 8 were amplified by polymerase chain reaction (PCR),followed by single strand conformation polymorphism(SSCP)analysis. Results Neither RFLP nor homozygous hemizygous,large fragment deletions in PTEN were found with Southern blot.But in the PCR?SSCP assay,one extra shift band of the same pattern was found after exon 5 amplification in 2 HCCs (5.9%,2/34).Extra shift bands were also discovered after exon 8 amplification in 2 HCCs (5.9%,2/34),11.8%(4/34) of both exons in HCCs. Results Neither RFLP nor homozygous hemizygous,large fragment deletions in PTEN were found with Southern blot.But in the PCR?SSCP assay,one extra shift band of the same pattern was found after exon 5 amplification in 2 HCCs (5.9%,2/34).Extra shift bands were also discovered after exon 8 amplification in 2 HCCs (5.9%,2/34),11.8%(4/34) of both exons in HCCs. Conclusions No deletions but mutations of PTEN in HCC were identified.