Hepatocellular carcinoma (HCC) is a leading cause of death worldwide. Using cDNA microarrays to characterize patterns of gene expression in HCC, we found consistent differences between the expression patterns in HCC compared with those seen in nontumor liver tissues. The expression patterns in HCC were also readily distinguished from those associated with tumors metastatic to liver. The global gene expression patterns intrinsic to each tumor were sufficiently distinctive that multiple tumor nodules from the same patient could usually be recognized and distinguished from all the others in the large sample set on the basis of their gene expression patterns alone. The distinctive gene expression patterns are characteristic of the tumors and not the patient; the expression programs seen in clonally independent tumor nodules in the same patient were no more similar than those in tumors from different patients. Moreover, clonally related tumor masses that showed distinct expression profiles were also distinguished by genotypic differences. Some features of the gene expression patterns were associated with specific phenotypic and genotypic characteristics of the tumors, including growth rate, vascular invasion, and p53 overexpression.

We have established a cell line (C666‐1) from undifferentiated nasopharyngeal carcinoma (NPC). This cell line consistently carries the Epstein‐Barr virus (EBV) in long‐term cultures. C666‐1 is a subclone of its parental cell line, C666, derived from an NPC xenograft of southern Chinese origin. It grows as an adherent culture and lacks contact inhibition. In addition, it is tumorigenic in athymic nude mice. The cells consistently express EBV‐encoded RNAs and are positively stained for cytokeratin, an epithelial marker. In addition, they express EBNA1 protein, LMP1 and LMP2 transcripts and thus resemble the EBV latency II pattern. The virus genotype is EBV‐1 with the latent membrane protein 1 gene showing a 30‐bp deletion at the carboxyl terminus, both consistent with findings in southern Chinese NPC tumours. Cytogenetic analysis revealed a sub‐diploid status with a chromosomal modal number of 45. C666‐1 is unique among NPC cell lines in that it carries EBV. These cells may serve as a good investigative tool as the viral latency pattern and genotype are observed in the majority of primary NPC biopsies from Chinese patients. Int. J. Cancer 83:121–126, 1999.

To evaluate whether major right hepatectomy using the anterior approach technique for large hepatocellular carcinoma (HCC) results in better operative and long-term survival outcomes when compared with the conventional approach technique. The anterior approach technique has been advocated recently for large right liver tumors. However, its beneficial effects on the operative and survival outcomes of the patients have not been evaluated prospectively. A prospective randomized controlled study was performed on 120 patients who had large (> or =5 cm) right liver HCC and underwent curative major right hepatic resection during a 57-month period. The patients were randomized to undergo resection of the tumor using the anterior approach technique (AA group, n = 60) or the conventional approach technique (CA group, n = 60). The anterior approach technique involved initial vascular inflow control, completion of parenchymal transection, and complete venous outflow control before the right liver was mobilized. Operative and long-term survival outcomes of the two groups were analyzed. Quantitative assessments of markers of circulating tumor cells at various stages of surgery of the two techniques were also assessed by plasma albumin-mRNA. The overall operative blood loss, morbidity, and duration of hospital stay were comparable in both groups. Major operative blood loss of > or =2 L occurred less frequently in the AA group (8.3% vs. 28.3%, P = 0.005). As a result, blood transfusion requirement and number of patients requiring blood transfusion were significantly lower in the AA group. Hospital mortality occurred in 1 patient in the AA group and 6 patients in the CA group (P = 0.114). Median disease-free survival was 15.5 months in the AA group and 13.9 months in the CA group (P = 0.882). Overall survival was significantly better in the AA group (median >68.1 months) than in the CA group (median = 22.6 months, P = 0.006). The survival benefit appeared more obvious in patients with stage II disease and patients with lymphovascular permeation of the tumor. The anterior approach was also found to associate with significantly lower plasma albumin-mRNA levels at various stages of surgery compared with the CA technique. On multivariate analysis, tumor staging, anterior approach hepatic resection, and resection margin involved by the tumor were independent factors affecting overall survival. The anterior approach results in better operative and survival outcomes compared with the conventional approach. It is the preferred technique for major right hepatic resection for large HCC.

We used several of the genetic lesions commonly associated with human liver tumors to reconstruct genetic progression to hepatocellular carcinoma and adenoma in mouse models. We initiated tumorigenesis with a transgene of the protooncogene MET or by hydrodynamic transfection of MET in combination with other genes into the livers of adult animals. Hepatocellular carcinoma in both instances arose from cooperation between MET and constitutively active versions of β-catenin. In contrast, adenomas were produced by cooperation between MET and defective signaling through the transcription factor HNF1α. Prompted by these findings, we uncovered a coincidence between activation of the protein-tyrosine kinase encoded by MET and activating mutations of β-catenin in a subset of human hepatocellular carcinomas. Inactivation of MET transgenes led to regression of hepatocellular carcinomas despite the persistence of activated β-catenin. The tumors eventually recurred in the absence of MET expression, however, presumably after the occurrence of one or more events that cooperated with activated β-catenin in lieu of MET . These results offer insight into hepatic tumorigenesis, provide mouse models that should be useful in the further study of hepatic tumorigenesis and for preclinical testing, and identify a subset of human hepatocellular carcinomas that may be susceptible to combination therapy directed against Met and the Wnt signaling pathway.