References

Notes: A human hepatoma cell line,HuH-7, which was established from a hepatocellular carcinoma,was found to replicate continuously in a chemically defined medium when the medium was supplemonted with Na2Se3O3. The cells grew better in this medium than in serum-containing medium without any adaptation period.Other established human hepatoma and hepatoblastoma cell lines, HuH-6,cl-5,PLC/PRF/5,huH-1,and, huH-4, also grew in the defined medium.
Reference ID: 1201

Notes: A chemically defined medium containing selenium was further improved, and the improved medium showed excellent ability to support growth and colony formation of a human hepatoma cell line, HuH-7. The improved defined medium (designated as IS-RPMI) contained small amounts of unsaturated fatty acids, inorganic trace elements including selenium, and HEPES buffer. Many of these additions exert only a small individual effect on the growth of cells, but their cumulative effects were substantial. HuH-7 cells replicated continuously with a doubling time of 47-51 hr in IS-RPMI. A conditioned medium from a semiconfluent population increased the colony-forming ability of HuH-7 cells in IS-RPMI. The addition of insulin to the medium gave good colony growth, thus duplicating the effect of the conditioned medium. Although some alterations of morphological and growth characteristics of HuH-7 cells were observed, the differentiated liver functions, as revealed by production of plasma proteins including high levels of alpha 1-fetoprotein, were maintained for a period of more than 3 years and through 70 passages under the above culture conditions
Reference ID: 2610

Notes: The regulation of alpha-fetoprotein (AFP) secretion and growth rate by various hormones in established human hepatoma (HuH-7, PLC/PRF/5, huH-1, huH-4, and KIM-1/c-4) and hepatoblastoma (HUH-6 Clone 5) cell lines was studied. These 6 cell lines replicated continuously in a chemically defined medium and secreted 84 ng (HuH-7) to 23 pg (huH-4) AFP per 24 h per 1 X 10(4) cells into the culture medium. The addition of insulin increased the growth rate of all examined cell lines and partially inhibited the AFP secretion in those cell lines except KIM-1/c-4, while the addition of dexamethasone inhibited the growth and stimulated the AFP secretion in all of the cell lines. The addition of 3,3',5- triiodothyronine inhibited the growth of all cell lines; however, different effects on the AFP secretion were observed depending on the cell lines used. Obviously, the AFP secretion was unrelated to the change in growth rate. When dexamethasone and N6-O2- dibutyryl cyclic AMP were added together, the AFP secretion was further stimulated. On the other hand, when dexamethasone and insulin were added simultaneously, the dexamethasone-mediated stimulation of AFP secretions was diminished. The data indicated that the regulatory mechanisms of AFP secretion by the hormones in the established human hepatoma and hepatoblastoma cell lines cannot be deduced according to the results of one cell line
Reference ID: 2611

Notes: Third Department of Internal Medicine, Osaka City University Medical School, Japan sseki@medosaka-cuacjpFAU - Seki, S
Abstract: BACKGROUND/AIMS: Although the mechanism of cancer metastasis has been gradually elucidated, less is known concerning the characteristics of human hepatocellular carcinomas (HCCs) with metastatic potential. We examined the expression of molecules that mediate cell-cell or cell-substrate interaction, nm23-H1 expression, and ultrastructural features of several human HCC cell lines. METHODOLOGY: Expression of E-cadherin, integrin (alpha3beta1), intracellular adhesion molecule-1 (ICAM-1), and nm23-H1 protein was analyzed by immunocytochemistry or Western blotting, and ultrastructural features were further studied by electron microscopy in 4 human HCC cell lines, PLC/PRF/5, HuH-7, OCUH-16, and Nuk-1 which were originally established from metastatic cells in lymph nodes at our institute. RESULTS: Neither E-cadherin, integrin, nor ICAM-1 was immunocytochemically detected in any of the 4 cell lines. Expression of nm23-H1 protein was weakly detected in OCUH-16, Nuk-1, and Huh-7 cells by Western blotting, but was clearly detected in PLC/PRF/5 cells by Western blotting. Ultrastructurally, metastatic Nuk-1 cells exhibited the intracytoplasmic canaliculus-like structures found in fibrolamellar carcinoma and the intracytoplasmic glandular lumina found in bile-duct carcinoma, while the other 3 cell lines did not. In addition, Nuk-1 cells expressed neither cytokeratin 8 nor cytokeratin 19. CONCLUSIONS: Nuk-1 cells, which are human HCC cells with metastasis to lymph nodes, alone exhibited intracytoplasmic canaliculus-like structures and glandular lumina, as well as a marked reduction of nm23-H1 protein, but did not express E-cadherin, integrin, or ICAM-1. Formation of both intracytoplasmic canaliculus-like structures and intracytoplasmic glandular lumina is one of the characteristics that may be involved in metastasis of HCC cells to lymph nodes, as is reduction of nm23-H1 protein
Reference ID: 5497

Notes: Institute for Virology, Johannes-Gutenberg University Mainz, Obere Zahlbacher Strasse 67, 55131 Mainz, GermanyFAU - Lohmann, V
Abstract: An estimated 170 million persons worldwide are infected with hepatitis C virus (HCV), a major cause of chronic liver disease. Despite increasing knowledge of genome structure and individual viral proteins, studies on virus replication and pathogenesis have been hampered by the lack of reliable and efficient cell culture systems. A full-length consensus genome was cloned from viral RNA isolated from an infected human liver and used to construct subgenomic selectable replicons. Upon transfection into a human hepatoma cell line, these RNAs were found to replicate to high levels, permitting metabolic radiolabeling of viral RNA and proteins. This work defines the structure of HCV replicons functional in cell culture and provides the basis for a long-sought cellular system that should allow detailed molecular studies of HCV and the development of antiviral drugs
Reference ID: 6276

Notes: Center for the Study of Hepatitis C, Laboratory of Virology and Infectious Disease, The Rockefeller University, 1230 York Avenue, New York, NY 10021, USAFAU - Blight, Keril J
Abstract: Hepatitis C virus (HCV) replication appears to be restricted to the human hepatoma cell line Huh-7, indicating that a favorable cellular environment exists within these cells. Although adaptive mutations in the HCV nonstructural proteins typically enhance the replicative capacity of subgenomic replicons in Huh-7 cells, replication can only be detected in a subpopulation of these cells. Here we show that self-replicating subgenomic RNA could be eliminated from Huh-7 clones by prolonged treatment with alpha interferon (IFN-alpha) and that a higher frequency of cured cells could support both subgenomic and full-length HCV replication. The increased permissiveness of one of the cured cell lines allowed us to readily detect HCV RNA and antigens early after RNA transfection, eliminating the need for selection of replication-positive cells. We also demonstrate that a single amino acid substitution in NS5A is sufficient for establishing HCV replication in a majority of cured cells and that the major phosphate acceptor site of subtype 1b NS5A is not essential for HCV replication
Reference ID: 6277

Notes: Laboratory of Virology and Infectious Disease, Center for the Study of Hepatitis C, The Rockefeller University, New York, NY 10021, USAFAU - Randall, Glenn
Abstract: RNA interference is a cellular process of gene silencing in which small duplexes of RNA specifically target a homologous sequence for cleavage by cellular ribonucleases. The introduction of approximately 22-nt small interfering RNAs (siRNAs) into mammalian cells can specifically silence cellular mRNAs without induction of the nonspecific IFN responses that are activated by longer RNA duplexes. We investigate in this article whether siRNAs can also silence the expression of the cytoplasmically replicating hepatitis C virus (HCV) RNAs by using a replicon system that supports robust HCV replication, but not the production of infectious virions. We report the efficient silencing of both cellular lamin AC and HCV RNAs in Huh-7 hepatoma cell lines supporting HCV replication. Silencing of HCV RNAs was dose dependent and specific, inasmuch as two HCV variants that differ by 3 nt within the target sequence were only silenced by the exact homologous sequence for each. siRNAs designed to target HCV RNA triggered an exponential decrease in HCV RNA, resulting in an 80-fold decrease in HCV RNA after 4 days. The introduction of siRNAs into cells with established HCV replication cured >98% of these cells of detectable HCV antigen and replication-competent HCV RNAs. These data support the principle of siRNA-based HCV antiviral therapy
Reference ID: 6278