Yin-Kun Liu

Invasion and metastasis of liver cancer: expression of intercellular adhesion molecule 1.

Abstract Purpose: To study the relationship between intercellular adhesion molecule 1 (ICAM-1) and liver cancer metastasis and to find predicting factors that could indicate the growth and metastasis of liver cancer. Methods: ICAM-1 expression in fresh tissue of normal liver and hepatocellular cancer (HCC) was examined by immunoperoxidase staining. Serum soluble intercellular adhesion molecule 1 (sICAM-1) from patients with a benign HCC tumor, and the expression of ICAM-1 in the orthotopically transplanted LCI-D20 tumor of a nude mouse liver cancer metastasis model, and in human hepatoma, the tumor surrounding tissue and normal liver, was analyzed semiquantitatively by the immuno-dot blot method. Tissue ICAM-1 expression (mRNA level) was detected by Northern blotting. Results: ICAM-1 expression in LD1-20 D metastatic liver cancer had a positive correlation with tumor size and the time after implantation. It increased suddenly as metastasis occurred being 3.03 ± 0.51 before metastasis and 8.24 ± 0.95 after metastasis, P < 0.01, then remained high, appending on the number of sites involved (monosite metastasis 5.48 ± 0.49, multisite metastasis 10.05 ± 1.17, P < 0.05). All six cases of normal liver samples were negative in anti-ICAM-1 immunohistochemical staining, 80.0% (36/45) of the HCC showed some ICAM-1 expression. The rate of positive cells was a little higher in large tumors, tumors with an intact capsule and tumors with metastasis, but there was no significant difference. It was noticed that two cancer emboli also had high ICAM-1 expression. The ICAM-1 concentration in HCC (13.43 ± 0.09) was higher than that in tumor surrounding the liver (5.89 ± 0.17, P < 0.01) and that in normal liver (4.27 ± 0.21, P < 0.01). sICAM-1, like tissue ICAM-1, was higher in HCC patients than in patients (with benign liver tumor and normal controls. Both tissue ICAM-1 and sICAM-1 were higher in the metastasis group than in the group without metastasis (tissue ICAM-1 20.24 ± 0.30 vs 10.23 ± 0.12 P < 0.05; sICAM-1 12.18 ± 0.25 vs 9.77 ± 0.54 P < 0.05). Northern blot analysis revealed that ICAM-1 expression, as indicated by mRNA level, was also higher in HCC and in cancer emboli than in tumor surrounding liver and normal liver. Conclusions: Tissue ICAM-1 and serum sICAM-1 could indicate the stage of HCC, and the potential of hepatoma cells for invasion and metastasis. They may play an important role in the metastasis cascade.

Expression of platelet-derived endothelial cell growth factor and vascular endothelial growth factor in hepatocellular carcinoma and portal vein tumor thrombus.

Purpose: Both platelet-derived endothelial cell growth factor (PD-ECGF) and vascular endothelial growth factor (VEGF) are known to promote the development of new blood vessels, which are fundamental to tumor growth and metastasis. We aimed at evaluating the gene expression of PD-ECGF and VEGF in hepatocellular carcinoma (HCC) and portal vein tumor thrombus (PVTT). Patients and methods: Surgical specimens (28 HCC, 28 nontumorous liver tissues and 18 PVTT) were studied by Northern blot analysis. The levels of PD-ECGF mRNA and VEGF mRNA expression were measured by densitometric scanning of the autoradiographs, and they were normalized to the level of expression of an internal control (glyceraldehyde-phosphate dehydrogenase) mRNA. Results: The expression rates of PD-ECGF mRNA in PVTT, HCC and nontumorous liver tissues were 77.8% (14/18), 67.9% (19/28) and 35.7% (10/28), being 88.9% (16/18), 75.0% (21/28) and 17.9% (5/28) respectively for VEGF mRNA. The expressions of PD-ECGF mRNA and VEGF mRNA were higher in HCC with PVTT than when PVTT was absent (P < 0.05). The PVTT was more often seen in patients with positive expression of both PD-ECGF mRNA and VEGF mRNA in HCC than in patients who were positive for only one of these factors or negative for both (P < 0.05). Conclusion: Both PD-ECGF and VEGF correlated well with the formation of PVTT of HCC.

Mutation and overexpression of the β-catenin gene may play an important role in primary hepatocellular carcinoma among Chinese people

Abstract Aim: To study the role of β-catenin gene mutation and expression in hepatocellular carcinogenesis. Method: Thirty-four hepatocellular carcinoma (HCC) specimens and adjacent para-cancerous tissues, and four normal liver tissues were analyzed. Subcellular distribution of β-catenin was examined by immunohistochemistry staining. Mutation and semiquantitative expression of β-catenin gene exon 3 mRNA were detected by RT-PCR-SSCP and in situ hybridization. Result: Immunohistochemistry showed that all normal liver tissues and para-cancerous tissues examined showed membranous-type staining for β-catenin protein, frequently with weak expression in the cytoplasm, but no β-catenin accumulation in nuclei was found; while in liver cancer, 21 cases (61.8%) of HCC examined showed accumulated type in cytoplasms or nuclei. On SSCP, 15 cases (44.1%) of HCC altogether displayed three kinds of characteristic mutational mobility shifts. No abnormal shifting bands were found in tissues from normal liver or para-cancerous area. The β-catenin gene exon 3 mRNA expression index of 34 HCCs was higher than that of para-cancerous tissue and normal liver tissue. Using in situ hybridization, the signal corresponding to β-catenin gene exon 3 mRNA was particularly strong in cytoplasm of HCC when compared with those of para-cancerous tissues and normal liver tissues. Conclusion: β-catenin gene mutation and overexpression may have a critical role in malignant progression of hepatic carcinogenesis among Chinese people.

The expression of the mdm2 gene may be related to the aberration of the p53 gene in human hepatocellular carcinoma.

Abstract The relationship between mdm2 gene expression and p53 gene mutation in hepatocellular carcinoma (HCC) and their correlation with the invasiveness of the disease were investigated in this study. Either the expression level of the mdm2 gene or the mutation rate of the p53 gene was higher in HCC than in paratumor liver tissues. Studies on the relationship between mdm2 and p53 revealed that mdm2 gene expression in HCC without p53 mutation was higher than when there was p53 mutation, while the p53 mutation rate in HCC with mdm2 overexpression was significantly lower than in HCC without mdm2 overexpression. Among 23 HCC with invasion, mdm2 gene overexpression was found in 6 patients while p53 mutation was found in the other 11 patients, and only 1 patient was found to have both mdm2 overexpression and p53 mutation. These results indicated that either mdm2 overexpression or p53 mutation may be related to the invasiveness of HCC. Considering that an autoregulatory feedback loop between the mdm2 and p53 genes may exist, wild-type P53 can induce the expression of mdm2 via a p53-binding site in the mdm2 gene, while MDM2 protein functions as a negative regulator of P53 protein. These results also suggest that mdm2 may be related to the high invasiveness of HCC through inactivating the tumor-suppressor function of the p53 gene.

Inhibitory effects of synthetic β peptide on invasion and metastasis of liver cancer

Purpose: To study the inhibitory effects of synthetic β peptide on invasion and metastasis of liver cancer. Methods: Membrane-type intercellular adhesion molecule-1 (ICAM-1) expression of SMMC-7721 cultured hepatoma cells (7721 cells) was detected by immunofluorescence cell flowmeter. The adhesion of 7721 cells to fibronectin (FN) was assayed by the MTT method. The adhesion of 7721 cells to 7721 cells, 7721 cells to endothelial cells, and 7721 cells to lymphocyte cells was detected by adhesion assay. LCI-D20 human liver cancer metastasis model in nude mice was used in this experiment. One hundred micrograms of β peptide per mouse were injected subcutaneously after tumor was resected premetastatically or postmetastatically to observe its effect on liver cancer metastasis after hepatectomy. Results: Membrane-type ICAM-1 expression of SMMC-7721 cells treated by β peptide was lower than that of the untreated cells. The adhesion of 7721 cells to FN, 7721 cells to 7721 cells, 7721 cells to endothelial cells, and 7721 cells to lymphocyte cells was also lower in the β peptide group than in the untreated group. Conclusions:β Peptide can block the adhesion of 7721 cells to FN, 7721 cells to some host cells in vitro, and inhibit HCC metastasis of LCI-D20 model posthepatectomy in vivo, so it could potentially act as an anti-metastasis drug.

The targeted expression of the human interleukin-2/interferon α2b fused gene in α-fetoprotein-expressing hepatocellular carcinoma cells

Abstract This study explores the use of a liver-specific albumin promoter and a tumor-specific α-fetoprotein (AFP) enhancer to achieve the regulated expression of the cytokine interleukin-2/interferon α2b (IL-2/IFNα2b) fused gene for treatment of hepatocellular carcinoma (HCC). The human AFP enhancer (EAFP) and albumin promoter (PALB) were amplified from human chromosome DNA by the polymerase chain reaction. A recombinant retrovirus was constructed including, as a selectable marker, the neoR gene and the IL-2/IFNα2b fused gene controlled by EAFP-PALB. The liver-targeted expression pattern of the IL-2/IFNα2b fused gene was observed when this product was tested in the culture medium of the infected cells (IL-2 activity was 850 IU/106 cells, IFNα activity was 320 IU/106 cells). Moreover, The growth of the IL-2/IFNα2b-fused-gene-infected HCC cells, SMMC7721, was clearly suppressed by the second week after innoculation of nude mice compared to the control SMMC7721 cells infected with LXSN and untreated SMMC7721 cells (0.5 ± 0.1 cm versus 1.4 ± 0.2 cm and 1.6 ± 0.2 cm, P < 0.05). The results showed that the combined transcriptional regulatory sequences of EAFP-PALB could control the targeted expression of cytokine genes in AFP-positive human HCC cells, and the expression level of the IL-2/IFNα2b fused gene was positively correlated to the level of AFP expression in the infected cells. The IL-2/IFNα2b fused protein that was expressed has the functions of both IL-2 and IFNα. Therefore, this study illustrates the superiority of using transcriptionally targeted recombinant retrovirus vectors in cytokine-based gene therapy.

Experimental study of the prophylactic and therapeutic effects of venin on metastasis and recurrence of liver cancer

ObjectiveTo study the inhibitory effect of venin on adhesion and invasive ability of SMMC-7721 ceils and to examine the prophylactic and therapeutic effect of venin on liver cancer metastasis and recurrence after hepatectomy.MethodsThe blocking effect of venin on the intercellular adhesive molecule (ICAM-1) of 7721 cells was analyzed by irnmunofluorescence How cytometry. The influence of venin on the invasive ability of 7721 cells was observed by cell-migration experimentation and detachment of 7721 cells attached to fibronectin (FM), and the influence of venin on adhesion of 7721 cells to FN by the MTT method, 7721 ceils to 7721 cells, 7721 cells lo lymphocytes, and 7721 cells to endoihelial cells by a cellular adhesion test. The preventive and therapeutic eftect of venin on metastasis and recurrence of a liver cancer model was observed in nude mice alter hepatectomy.ResultsThe expression of ICAM-1 in the venin-treated group was significantly lower than that in the untreated group. Venin could not inhibit the invasive ability of 7721 cells, and could not exfoliate the 7721 cells adhered to FN. It could inhibit the adhesion between 7721 cells and 7721 cells, and between 7721 and endothehal cells, but could not inhibit the adhesion between 7721 and lymphocytes. The nude mice treated with venin had less intrahepatic or extrahepatic metastases and recurrences after hepatectomy.ConclusionVenin can inhibit the adhesive ability of SMMC -7721 cells and can also prevent and treat the metastasis and recurrence of liver cancer in nude mice after hepalectomy.