肝癌组织甲胎蛋白表达特点及其基因片段的扩增分析

Characteristics of alpha-fetoprotein expression and amplification analysis of AFP-mRNA fragment in human hepatoma tissues

目的探讨肝癌组织甲胎蛋白(AFP)表达的病理学特点及其基因分析的临床价值。方法以免疫组织化学法研究AFP在肝癌及癌周组织中的胞内分布及其表达;并从肝癌的癌灶、癌旁组织中制备总RNA,以巢式聚合酶链反应(nested_PCR)扩增不同癌组织AFP_mRNA片段,以探讨AFP表达的临床病理学特征及其AFP_mRNA分析的应用价值。结果肝癌细胞及癌旁肝细胞的胞浆中,均可见AFP阳性的棕黄色颗粒,癌组织中AFP阳性表达率为73.3%,癌旁组织中为40.0%,中、低分化组肝癌中AFP的表达阳性率明显高于高分化组肝癌(P<0.05),且癌旁组织中AFP的表达强度明显低于肝癌的癌灶组织。肝癌组织、癌周组织的总RNA表达水平存在差别,癌组织中AFP_mRNA片段扩增全数阳性(100%),显著高于癌周组织(P<0.01)。结论肝癌不同组织中AFP表达存在差异,AFP_mRNA分析有助于肝癌的早期发现和诊断。

Objective To explore the pathologic characteristics of alpha-fetoprotein （AFP） and the clinical value of their gene analysis in human hepatocellular carcinomas （HCCs）, Methods The cellular distribution of AFP expression in HCC and their adjacent tissues were investigated by immunohistochemical technique. Total RNAs were extracted from HCCs. The cDNA was synthesized through random primers and reverse transcriptase. The gene fragments of AFP were amplified by nestedpolymerase chain reaction （nested-PCR） assay. Results The AFP-positive material was huffy fine particle which mainly localized in the cytoplasm. The incidence of AFP was 73.3 % in HCCs, and 40.0% in their adjacent tissues, respectively. The AFP expression in HCCs with moderate or low differentiation was significantly stronger than that of HCCs with high differentiation （ P 〈 0.05） . The incidence of AFP gene fragment was 100% in cancerous tissues and 60% in paracancerous, respectively. The incidence of the former was significantly higher than that of the latter （ P 〈 0.01 ）. Conclusion The different AFP expression present in different parts of HCCs, and AFP-mRNA is a useful genetic marker for early diagnosis of HCC.