Hepatocyte growth factor, transforming growth factor alpha, and their receptors as combined markers of prognosis in hepatocellular carcinoma

ADAM17 mRNA expression and pathological features of hepatocellular carcinoma

AIM: To study the expression of a disintegrin and metalloproteinase 17 (ADAM17) mRNA in hepatocellular carcinoma (HCC) and to evaluate the relationship between ADAM17 mRNA expression and clinicopathological features of HCC.

METHODS: Hepatocellular carcinomas (HCC) from 31 cases were divided into small HCC (SHCC), nodular HCC (NHCC) and solitary large HCC (SLHCC) according to tumor diameter and the number of nodes. ADAM17 mRNA expressions were compared among those groups by means of semi-quantitative reverse transcription polymerase chain reaction (RT-PCR). The relationship between ADAM17 mRNA expression level and clinicopathological features of HCC was evaluated.

RESULTS: NHCC had lower differentiation and was more frequently of microvascular invasion (10/12) than SHCC (3/11) and SLHCC (3/8) (P < 0.05), but no statistical difference was observed between SHCC and SLHCC comparing their clinicopathological features. ADAM17 mRNA expression was detected in 77.4% (24/31) of HCC tissues and was significantly higher than that in paired non-cancerous liver tissues in which only 35.5% (11/31) of the samples were detected of the expression (P < 0.05). The expression of ADAM17 mRNA was much higher in NHCC than in SHCC and SLHCC (P < 0.05), while no significant difference was discovered between SHCC and SLHCC. The quantities of ADAM17 mRNA were significantly higher in poorly differentiated HCC than in well or moderately differentiated HCC, but no statistical difference was found concerning liver cirrhosis, tumor capsule formation or microvascular invasion of the cancer.

CONCLUSION: The increased expression of ADAM17 may play a key role in the development of HCC. The expression levels of ADAM17 mRNA varied among different pathological types of HCC. Lower mRNA expression of ADAM17 mRNA in SLHCC may be associated with the better molecular pathological features of SLHCC.

Effects of liver sinusoidal endothelial cells on proliferation of hepatocytes after partial hepatectomy in rats

AIM: To explore the effects of liver sinusoidal endothelial cells on the proliferation of the regenerative hepatocytes after partial hepatectomy in normal rats.

METHODS: A method to separate and culture hepatocytes and liver sinusoidal endothelial cells (LSEC) was established and the hepacytes and sinusoidal endothelial cells of regenerative liver were separated and cultured at different time points after partial hepaectomy in normal rats. The experiment was divided into two groups: operation group (OP) and sham operation group (SO). The cultivation of hepatocytes was divided into two groups: group A (hepatocytes) and group B (hepatocytes + supernatant of LSEC). The expression index of PCNA in hepatocytes was assayed by immunohistochemistry, and the level of synthesis of DNA in regenerative hepatocytes was assayed by radio-immunity.

RESULTS: The expression index of PCNA in hepatocytes cultured in group B increased more significantly than that in group A after partial hepatectomy in 6h and 24 h (5.9±0.1 vs 8.9±0.1 P < 0.05; 38.6±2.6 vs 58.0±3.9 P < 0.01),and so did the level of synthesis of DNA in regenerating hepatocytes cultured in group B than that in group A after partial hepatectomy in 6 h and 24 h (226±18 vs 8.9±0.1 P < 0.05; 38.6±2.6 vs 58.0±3.9 P < 0.01).

CONCLUSION: The proliferating ability and the synthesis of DNA in hepatocytes after partial hepatectomy are enhanced by the supernatant from LSEC in vitro.

Effect of c-myc, Ki-67, MMP-2 and VEGF expression on prognosis of hepatocellular carcinoma patients undergoing tumor resection

AIM: To explore the effect of c-myc, Ki-67, MMP-2 and VEGF expression on prognosis of hepatocellular carcinoma (HCC) patients undergoing tumor resection.

METHODS: Primary HCC patients underwent tumor resection were retrospectively analysed. The maximum size of the tumor was less than 5 cm, there was only one nodule in each patient. No chemoembolization was performed before resection. They were followed up after resection, and the time of recurrence was recorded. They were divided into 2 groups: group A (15 cases): tumor recurrence within 1 year after tumor resection, and group B (15 cases): with or without tumor recurrence 2 years after tumor resection. Pathological slices were made with tumor wax-sample. Immunohistochemistry staining was performed with c-myc, Ki-67, MMP-2 and VEGF monoclonal antibodies. Staining intensity was quantitatively analysed with a pathological diagram-writing analyzing system. The expressing intensity differences of stained molecules in cancer tissue and para-cancer were analysed.

RESULTS: c-myc, Ki-67, MMP-2 and VEGF expressing intensities in cancer tissue in group A were higher than those in group B (P values were 0.010, 0.030, 0.022 and 0.004, respectively), but they were not significantly different in para-cancer tissue in groups A and B (P values were 0.334, 0.343, 0.334 and 0.334, respectively).

CONCLUSION: The expression of c-myc, Ki-67, MMP-2 and VEGF in cancer tissue is related to the recurrence of HCC after tumor resection.

Reactive oxygen species mediate Met receptor transactivation by G protein-coupled receptors and the epidermal growth factor receptor in human carcinoma cells

Cross-communication between the Met receptor tyrosine kinase and the epidermal growth factor receptor (EGFR) has been proposed to involve direct association of both receptors and EGFR kinase-dependent phosphorylation. Here, we demonstrate that in human hepatocellular and pancreatic carcinoma cells the Met receptor becomes tyrosine phosphorylated not only upon EGF stimulation but also in response to G protein-coupled receptor (GPCR) agonists. Whereas specific inhibition of the EGFR kinase activity blocked EGF- but not GPCR agonist-induced Met receptor transactivation, it was abrogated in the presence of a reducing agent or treatment of cells with a NADPH oxidase inhibitor. Both GPCR ligands and EGF are further shown to increase the level of reactive oxygen species within the cell. Interestingly, stimulation of the Met receptor by either GPCR agonists, EGF or its cognate ligand HGF, resulted in release of Met-associated beta-catenin and in its Met-dependent translocation into the nucleus, as analyzed by small interfering RNA-mediated knockdown of the Met receptor. Our results provide a new molecular explanation for cell surface receptor cross-talk involving the Met receptor and thereby link the wide diversity of GPCRs and the EGFR to the oncogenic potential of Met signaling in human carcinoma cells.