The analysis of γ-glutamyl transpeptidase gene in different type liver tissues

Low alpha-fetoprotein HCC and the role of GGTP

BACKGROUND

HCC patients are heterogeneous in terms of both tumor and liver factors. Alpha-fetoprotein (AFP) is an important prognostic tumor marker for those patients with elevated AFP levels.

AIMS

To examine the differences in HCC patients with high or low AFP levels in blood and evaluate the prognostic parameters in low AFP patients.

METHODS

A cohort of 2,440 HCC patients from 11 Italian medical centers was studied. AFP-positive patients were compared to AFP-negative ones, and the blood and tumor parameters of AFP-negative patients were examined.

RESULTS

Low blood AFP levels were found in 58% of the total cohort, in 64% of patients with small HCCs, and in 51% of patients with large HCCs. In patients with large tumors, platelet and gamma glutamyl transpeptidase (GGTP) levels, tumor multifocality and portal vein thrombosis (PVT) incidence were all greater than in patients with small tumors, regardless of AFP status. Patients with higher AFP levels had worse survival rates than those with low AFP in each tumor size group. In patients with small tumors, the elevated AFP was associated with significantly increased PVT and worse survival. In patients with large tumors, the elevated AFP was associated with significantly higher GGTP, ALKP, and bilirubin levels, as well as with increased PVT and multifocality, and worse survival. Low-AFP patients with high GGTP levels had worse survival than patients with low GGTP levels.

CONCLUSION

Patients with low AFP were the majority in this cohort, and patients with elevated GGTP had worse prognosis than those with low GGTP. GGTP may be a useful tumor and prognosis marker in low-AFP patients. AFP-negative patients are important to identify due to their enhanced survival.

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

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 hepatoma-specific 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.

Serum tumor markers for detection of hepatocellular carcinoma

Hepatocellular carcinoma (HCC) is one of the most frequent malignant tumors and is the second most common cause of cancer death in China. Therefore, it is very important to detect this disease and the recurrence at its earlier period. Serum tumor markers, as the effective method for detecting hepatocellular carcinoma for a long time, could be divided into 4 categories: oncofetal antigens and glycoprotein antigens; enzymes and isoenzymes; genes; and cytokines. Serum alpha fetoprotein (AFP) is the most widely used tumor marker in detecting patients with hepatocellular carcinoma, and has been proven to have capability of prefiguring the prognosis. However, it has been indicated that AFP-L3 and DCP excel AFP in differentiating hepatocellular carcinoma from nonmalignant hepatopathy and detecting small hepatocellular carcinoma. Some tumor markers, such as human cervical cancer oncogene and human telomerase reverse transcriptase mRNA, have also been indicated to have higher accuracies than AFP. Furthermore, some other tumor markers, such as glypican-3, gamma-glutamyl transferase II, alpha-l-fucosidase, transforming growth factor-beta1, tumor-specific growth factor, have been indicated to be available supplementaries to AFP in the detection. AFP mRNA has been shown to correlate with the metastasis and recurrence of HCC, and it may be the most useful marker to prefigure the prognosis. Some other markers, such as gamma-glutamyl transferase mRNA, vascular endothelial growth factor, and interleukin-8, could also be used as available prognostic indicators, and the simultaneous determination of AFP and these markers may detect the recurrence of HCC at its earlier period.