GGT亚组分及基因亚型与肝癌的特异性诊断

Specific diagnosis of gamma-glutamyl transferase subfraction and its genotyping for hepatocellular carcinoma

肝病及肝外肿瘤患者血γ-谷氨酰移换酶(GGT,EC 2.3.2.2)总活性均异常,肝癌患者血清经聚丙烯酰胺梯度凝胶电泳,可将GGT分出十多种亚组分(Ⅰ,Ⅰ′,Ⅱ,Ⅱ′,β,δ,ε,φA,ⅦB,φC,γA,γB),而其中Ⅰ′,Ⅱ,Ⅱ′为肝癌所特有,被称为肝癌特异性GGT(HS-GGT).肝GGT基因表达与肝癌发展密切相关,其基因亚型有胎肝型(F)、胎盘型(P)和肝癌细胞型(H),基因型H主要见于肝癌组织.众多的基础及临床研究证实HS-GGT和基因H亚型为肝癌特异标志,具有较高的特异性和敏感性,其分析有助于肝癌诊断与鉴别.

Abnormal expression of total γ-glutamyl transferase （GGT, EC 2.3.2.2） activity can be found in patients with different liver diseases and extrahepatic tumors. Circulating GGT from hepatocellular carcinoma （HCC） patients can be divided into different isoforms （ Ⅰ, Ⅰ′, Ⅱ, Ⅱ′,β,δ,ε,φA, ⅦB, φC, γA, γB） by using PAGE. Some of these isoforms （Ⅰ′, Ⅱ and Ⅱ′, and hepatomaspecific GGT, HS-GGT） can be detected in sera of HCC patients. Hepatic GGT gene expression may be closely related to the development of HCC. The human cDNA sequences from fetal liver, placenta and HepG2 cells （H） were investigated. The genotype H was predominant in cancerous tissues of HCC. Both HS-GGT and genotype H were confirmed as useful specific HCC markers, with higher specificity and sensitivity, and their analysis may be useful for HCC diagnosis and differentiation.