抑癌基因FHIT第8和第5外显子在原发性肝癌中纯合性缺失与点突变的研究

目的　对 2 0例原发性肝细胞肝癌 (HCC)的抑癌基因 FHIT外显子 5、外显子 8的纯合性缺失和点突变进行检测。方法　收集 HCC手术标本 ,提取癌细胞 DNA,采用 PCR方法研究 FHIT外显子 5、外显子 8的纯合性缺失 ;使用 PCR- SSCP方法研究 FHIT外显子 5和外显子 8的点突变。结果　发现在 2 0例 HCC中外显子 5的纯合性缺失率为 10 .0 (2 / 2 0 ) ,外显子 8的纯合性缺失率为 30 .0 % (6 / 2 0 ) ;有 1例外显子 5和外显子 8均缺失 ;FHIT的异常率为 35 .0 % (7/ 2 0 )。在被检的肿瘤组织细胞中 ,未发现 FHIT外显子 5和外显子 8存在点突变。在被检的正常细胞中未发现 FHIT缺失和点突变的情况。结论　 FHIT的缺失只发生在 HCC的肿瘤细胞中。在 HCC中 ,外显子 (尤其是外显子 8)的纯合性缺失是 FHIT基因失活的重要方式之一。点突变可能不是 HCC中 FHIT失活的主要方式

Analysis of homozygous deletion and point mutation of FHIT gene exon5 and exon8 in hepatocellular carcinoma

Objective To investigate the homozygous deletion and point mutation of exon5 and exon8 of FHIT a candidate tumor suppressor gene in hepatocellular carcinoma (HCC). Methods Twenty surgical samples of HCC were collected and diagnosed by pathology. DNA was extracted from these tissues. The method of polymerase chain reaction (PCR) was performed to analyze the homozygous deletion of exon5 and exon8 of FHIT and the method of polymerase chain reaction single strand confirmation polymorphism (PCR SSCP) was applied to analyze the point mutation of exon5 and exon8 of FHIT.Results In the 20 samples of HCC,homozygous deletion of FHIT exon5 was detected in 2 cases (10.0%)and homozygous deletion of FHIT exon8 in 6 cases (30.0%). One of 2 cases lost both exon5 and exon8. So the total deletion rate of FHIT in HCC was 35.0% (7/20). In lymphocytes of 10 normal controls,there were no deletion and point mutation of FHIT. In HCC which were not homozygous deletion of FHIT exon5 and exon8,there were not point mutation of FHIT exon5 and exon8. Conclusion The results suggest that the abnomal FHIT is only detected in HCC tissues,that the homozygous deletion of FHIT exon (especial exon8) may be a major way of inactivation of FHIT gene. The results also suggest that the point mutation of FHIT exon5 and exon8 may not be a major way of inactivation of FHIT gene in garstric carcinoma and HCC.