mRNA levels of nm23 in murine ascites hepatoma (H22) clones with different lymphatic metastatic potential

Nm23/NDP kinases in hepatocellular carcinoma

One of the most aggressive cancers is hepatocellular carcinoma, which is associated with a very poor patient outcome due to a high recurrence rate and metastatic spread. NM23, the first metastasis suppressor gene to be identified, has been widely studied in human cancers. However, conflicting results have been obtained depending on the tumor type and the evaluation protocol. The current knowledge of NM23 as a diagnostic and/or prognostic marker in hepatocellular carcinoma is reviewed herein. Most studies demonstrate an inverse association between the expression of NM23-H1 and the metastatic potential, which is not observed with the closely related NM23-H2 isoform. Transfection of metastatic hepatoma cells with NM23 reduced their metastatic potential, as for other tumor cell lines. The demonstration of a causative role of NM23 in metastatic dissemination in a mouse model of hepatocarcinoma suggests that hepatocarcinoma-derived cells could be good models for the analysis of the molecular mechanisms involved in NM23 action.

Effect of hepatoma H22 on lymphatic endothelium in vitro

AIM: To determine the effect of metastatic hepatoma cells on lymphangioma-derived endothelium, and to establish in vitro model systems for assessing metastasis-related response of lymphatic endothelium.

METHODS: Benign lymphangioma, induced by intraperitoneal injection of the incomplete Freund’s adjuvant in BALB/c mice, was embedded in fibrin gel or digested and then cultured in the conditioned medium derived from hepatoma H22. Light and electron microscopy, and the transwell migration assay were used to determine the effect of H22 on tissue or cell culture. Expressions of Flt-4, c-Fos, proliferating cell nuclear antigen (PCNA), and inducible nitric oxide synthase (iNOS) in cultured cells, and content of nitric oxide in culture medium were also examined.

RESULTS: The embedded lymphangioma pieces gave rise to array of capillaries, while separated cells from lymphangioma grew to a cobblestone-like monolayer. H22 activated growth and migration of the capillaries and cells, induced expressions of Flt-4, c-Fos, PCNA and iNOS in cultured cells, and significantly increased the content of NO in the culture medium.

CONCLUSION: Lymphangioma-derived cells keep the differentiated phenotypes of lymphatic endothelium, and the models established in this study are feasible for in vitro study of metastasis-related response of lymphatic endothelium.

Hepatocellular carcinoma--cause, treatment and metastasis

In the recent decades, the incidence of hepatocellular carcinoma (HCC) has been found to be increasing in males in some countries. In China, HCC ranked second of cancer mortality since 1990s. Hepatitis B and C viruses (HBV and HCV) and dietary aflatoxin intake remain the major causative factors of HCC. Surgery plays a major role in the treatment of HCC, particularly for small HCC. Down-staging unresectable huge HCC to smaller HCC and followed by resection will probably be a new approach for further study. Liver transplantation is indicated for small HCC, however, some issues remain to be solved. Different modes of regional cancer therapy for HCC have been tried. Systemic chemotherapy has been disappointing in the past but the future can be promising. Biotherapy, such as cytokines, differentiation inducers, anti-angiogenic agents, gene therapy and tumor vaccine will probably play a role, particularly in the prevention of tumor recurrence. HCC invasiveness is currently the major target of study. Tremendous works have been done at the molecular level, which will provide clues for biomarker of HCC progression as well as targets for intervention.

Genome-wide analyses on loss of heterozygosity in hepatocellular carcinoma in Southern China

BACKGROUND/AIMS

To conduct a genome-wide analysis of loss of heterozygosity (LOH) and its clinical significance in hepatocellular carcinoma (HCC) in Southern China where high incidence of HCC was documented.

METHODS

LOH of 382 microsatellite loci on all autosomes were detected with polymerase chain reaction-based microsatellite polymorphism analyses in 104 HCC tumor tissues.

RESULTS

High frequency of LOH (>55.7%) was observed on chromosome 1p, 1q, 2q, 3p, 4q, 6q, 8p, 9p, 13q, 16q, and 17p. LOH rates on loci D4S2964 (4q21.21), D8S277 (8p23.1-pter) and D17S938 (17p13.1-p13.3) were significantly higher in cases with positive HBsAg than in those with negative HBsAg. Similarly, LOH on loci D1S214 (lp36.3), D1S2797 (1p34) and D3S3681 (3p11.2-p14.2) were more frequently detected in tumors with intrahepatic metastasis than in those without.

CONCLUSIONS

Status of LOH in HCC in Southern China is similar to that reported previously in other countries and areas. However, we firstly identified high-frequency LOH on chromosome 3p in HCC. Furthermore, HBV infection, as well as tumor intrahepatic metastasis, may be correlated with allelic losses on certain chromosome regions.