Characterization of a novel rat cholangiocarcinoma cell culture model-CGCCA.

AIM: To characterize a culture model of rat CCA cells, which were derived from a transplantable TTA-induced CCA and designated as Chang Gung CCA (CGCCA). METHODS: The CGCCA cells were cultured at in vitro passage 12 times on a culture dish in DMEM medium. To measure the doubling time, 10(3) cells were plated in a 96-well plate containing the growth medium. The cells were harvested 4 to 10 d after seeding, and a standard MTT assay was used to measure the growth. The phenotype of CACCA cell and xenograft was determined by immunohistochemical study. We also determine the chromosomal alterations of CGCCA, G-banding and spectral karyotyping studies were performed. The CGCCA cell line was transplanted into the nude mice for examining its tumorigenicity. 2-Deoxy-2-((18)F)fluoro-D-glucose (FDG) autoradiography was also performed to evaluate the FDG uptake of the tumor xenograft. RESULTS: The doubling time for the CGCCA cell line was 32 h. After transplantation into nude mice, FDG autoradiography showed that the tumors formed at the cell transplantation site had a latency period of 4-6 wk with high FDG uptake excluding necrosis tissue. Moreover, immunohistochemical staining revealed prominent cytoplasmic expression of c-erb-B2, CK19, c-Met, COX-II, EGFR, MUC4, and a negative expression of K-ras. All data confirmed the phenotypic features of the CGCCA cell line coincide with the xenograft mice tumors, indicating cells containing the tumorigenicity of CCA originated from CCA. In addition, karyotypic banding analysis showed that the diploid (2n) cell status combines with ring and giant rod marker chromosomes in these clones; either both types simultaneously appeared or only one type of marker chromosome in a pair appeared in a cell. The major materials contained in the marker chromosome were primarily identified from chromosome 4. CONCLUSION: The current CGCCA cell line may be used as a non-K-ras effect CCA model and to obtain information and reveal novel pathways for CCA. Further applications regarding tumor markers or therapeutic targeting of CCA should be addressed accordingly.

Expression of ezrin is associated with invasion and dedifferentiation of hepatitis B related hepatocellular carcinoma.

BACKGROUND: Hepatocellular carcinoma (HCC) is the fifth most common malignancy in the world and constitutes the leading cause of cancer-related death among men, and second among women in Taiwan. Liver cirrhosis and HCC are relatively prevalent, and 80% to 85% of the patients with these conditions have positive results for hepatitis B surface antigen in Taiwan. Only 5% of the general population is seronegative for all hepatititis B virus (HBV) markers. This is the first study to determine the role of ezrin upon HBV HCC cell and patients with HBV HCC undergoing hepatectomy METHODS: Immunohistochemical study with ezrin in 104 human HBV-HCC cases were carried out to investigate its association with the clinicopathological features and the outcomes of 104 HBV-HCC patients undergoing hepatetomy. In addition, DNA constructs including the wild type ezrin (wt-ezrin) and mutant ezrin Tyr353 (Y353) were transfected into Hep3B cell to study its role in tumor invasion and differentiation. RESULTS: HBV HCC patients with ezrin over-expression independently have smaller tumor size, cirrhotic liver background, poor tumor differentiation, and more vascular invasion. Ezrin expression status has no impact on survival for HBV-HCC patients undergoing hepatectomy. The in vitro assay showed that wt-ezrin Hep3B cells have a significant higher level of AFP secretion and higher invasion ability as compared with the control and Y353- ezrin Hep3B cells. CONCLUSION: Ezrin over-expression contributed to de-differentiation and invasion of HBV-HCC cell. HBV-HCC patients with ezrin over-expression were independently associated with tumor with smaller size, cirrhotic liver background, poor differentiation, and vascular invasion.

Prognostic value of MUC4 for mass-forming intrahepatic cholangiocarcinoma after hepatectomy.

Cholangiocarcinoma (CCA), a lethal malignancy afflicting many thousands of patients throughout the world, develops through a multi-step progression. We have established an oral thioacetamide-induced model of rat CCA recapitulating the histologic progression of human CCA, especially for mass-forming CCA (MF-CCA). Our previous DNA microarray study showed MUC4 is overexpressed in rat CCA. Herein, we investigated the prognostic value of MUC4 for predicting overall survival rate (OS) for MF-CCA patients undergoing hepatectomy. Overexpression of MUC4 in rat CCA is demonstrated by RT-PCR. From the archives of Chang Gung Memorial Hospital, 53 MF-CCA patients undergoing hepatectomy were selected for an immunohistochemical study of MUC4. Fifteen clinicopathological variables (including MUC4 staining status) were used for survival analysis. MUC 4 is overexpressed in rat CCA. Fifty-three MF-CCA patients, 26 men and 27 women, with a median age of 60 years (range: 29-89) were studied. During the median follow-up duration of 14.7 months, the OS rates at 1, 3, and 5 years were 58.8, 25.5, and 16.5%, respectively. Univariate analysis showed that an absence of physical findings, better nutritional status, small tumor size, negative lymph node metastasis, an absence of MUC4 staining, and curative hepatic resection were associated with favorable OS rate for MF-CCA patients after hepatectomy. However, multivariate Cox proportional hazard analysis showed that an absence of MUC4 staining, small tumor size, and curative hepatectomy independently predicted MF-CCA patients with favorable OS rate after hepatectomy. In conclusion, an absence of MUC4 staining, small tumor size, and curative hepatectomy could independently predict MF-CCA patients with favorable OS rate after hepatectomy.