Sheng-Long Ye

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.

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.

Apoptosis of human BEL-7402 hepatocellular carcinoma cells released by antisense H-ras DNA-in vitro and in vivo studies

Recent findings suggest that over-expression of activated H-ras inhibited apoptotic cell death by blocking the activity of apoptotic endonuclease(s). This study was designed using antisense H-ras oligodeoxynucleotides (ODN) to evaluate whether alterations of H-ras expression in BEL-7402 human hepatocellular carcinoma cells could influence the induction of apoptosis in vitro and in vivo. We found that, in vitro, continuous suppression of H-ras expression could decrease the proliferation of BEL-7402 cells and inhibit H-ras-induced entry into S phase. In situ end labeling showed that a large number of cells underwent apoptotic cell death after treatment with antisense H-ras ODN (P<0.01), and gel electrophoresis of DNA extracted from these cells demonstrated a typical DNA ladder, characteristic of apoptosis. In vivo study indicated that pretreatment with antisense H-ras significantly retarded tumor growth in comparison with the untreated controls or tumors treated with non-specific ODN (P<0.01,P<0.01). In situ end-labeling revealed that pronounced apoptotic nuclei were also present in the tissue treated with antisense H-ras ODN (P<0.01). Immunocyto-histochemical study showed that expression of p21H-ras was significantly decreased after treatment with antisense H-ras. These results indicate that suppression of H-ras over-expression by antisense ODN could effectively inhibit tumor growth and revive the apoptotic pathway by releasing the activity of apoptotic endonuclease(s). The data also suggest the need for further studies to elucidate molecular events involved in antisense H-ras-released apoptosis and evaluate its therapeutic implications.

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.

Treatment of hepatocellular carcinoma: A summary of 33 years' experience

Hepatocellular carcinoma (HCC), the most common type (90-95%) of primary liver cancer (PLC), causes 100,000 deaths every year in China. However, based on various strategies aimed at controlling this neoplasm, HCC has become “partly curable” instead of “incurable.” In China, hepatectomy for HCC started in the 1950s, liver cancer cell lines were established in the 1960s, field work in high risk areas, including epidemiology, etiology, and screening, have been conducted from the 1970s [1,2], and small HCC resection became an important clinical feature in the 1970s and 1980s [3–7]. During the past ten years, substantial progress has been made in the field of basic liver cancer research, studies have focused on the relation between hepatitis B virus (HBV) and HCC, a set of protooncogenes and HCC-related genes have been studied, and cytoreduction and sequential resection for unresectable HCC have become new trends [8].

Multimodality treatment of hepatocellular carcinoma

Abstract By 1996, 2898 patients with pathologically proven hepatocellular carcinoma (HCC) had been treated at the Liver Cancer Institute of Shanghai Medical University. The 5 year survival in the entire series was 36.2%, being increased from 4.8% in 1958–70, 12.2% in 1971–83, to 50.5% in 1984–96 and 274 patients had survived more than 5 years. The increase in the survival rate could be attributed to the decreasing mean tumour diameter (11.7, 10.5 and 9.5 cm, respectively) and multimodality treatment. In addition to small HCC resection (5 year survival 64.9%, n = 735) and large HCC resection (5 year survival 37.4%, n = 1050), the following deserves to be mentioned. First, the 5 year survival of unresectable HCC treated by palliative surgery increased from 0% to 7.2% to 20.0%, which was related to the increase in use of multimodality treatment, particularly in those followed by second‐stage resection. Second, cytoreduction and sequential resection is a new field with a significant potential in the treatment of localized unresectable HCC in a cirrhotic liver. Cytoreduction can be achieved by surgery, such as hepatic artery ligation, cannulation, cryosurgery and their combination, and followed by intrahepatic arterial chemoembolization, targeting therapy or regional radiotherapy. Ninety of 647 patients with unresectable HCC so treated had marked shrinkage of tumour and received second‐stage resection; the 5 year survival was 71.4%. Third, non‐surgical cytoreduction was mainly achieved by transcatheter arterial chemoembolization (TACE); for 70 patients with second‐stage resection following TACE, the 5 year survival was 56.0%. Finally, re‐resection of subclinical recurrence of tumour after curative HCC resection was performed in 155 patients; the 5 year survival calculated from the first resection was 50.9%, which played an important role in increasing the 5 year survival in the resection group (from 13.0% to 29.5% to 56.2%). It is concluded that multimodality treatment with combined and sequential use of different modalities and repeated use of some modalities is of substantial benefit for localized unresectable HCC.