title: The efficacy of 2',2'-difluorodeoxycytidine (gemcitabine) combined with interferon in human renal cell carcinoma cell lines.
abstract: The present in vitro study on three human renal cell carcinoma (RCC) cell lines (A-498, ACHN, SN12C) evaluated the efficacy of 2',2'-difluorodeoxycytidine (dFdC, gemcitabine), vinblastine (VBL), rhu-interferon-alpha (IFN-alpha) and rhu-interferon-gamma (IFN-gamma) alone or in combinations. The cytotoxicity was measured by using the sulphorhodamine B colorimetric cytotoxicity assay. Analyses were made from cells being continuously long-term (4 weeks) or short-term (4 h) with IFN-alpha or IFN-gamma with regard to the cytotoxicity of the chemotherapeutic agents. dFdC was more cytotoxic against ACHN and A-498 cells compared to VBL. Pre-treatment with IFN-alpha enhanced growth inhibition caused by dFdC (4/4 cell lines) and VBL (2/3 cell lines), and was more effective than IFN-gamma. Pre-exposure with IFN-alpha sensitized SN12C and ACHN cells for dFdC. A-498 cells achieved a decreased sensitivity to dFdC and VBL after pre-exposure to IFN-gamma. The resistance of newly established dFdC-resistant SN12C cells (23-times) decreased when pre-treated with IFN-alpha. The data demonstrate efficacy of dFdC in human RCC at concentrations below clinically achievable doses. dFdC was more effective compared to VBL. Combined therapy preferentially with IFN-alpha increased cytotoxicity of dFdC in vitro. In vivo studies in nude mice xenografts are under investigation to support these observations.
authors.affiliation: Department of Urology, University of Aachen, D-52057 Aachen, Germany.
authors.forename: D
authors.initials: D
authors.lastname: Rohde
authors.forename: H K
authors.initials: HK
authors.lastname: Hayn
authors.forename: J
authors.initials: J
authors.lastname: Blatter
authors.forename: G
authors.initials: G
authors.lastname: Jakse
mesh_terms: D000970:Antineoplastic Agents / Q000008:administration & dosage / Q000494:pharmacology* / Q000627:therapeutic use; D000972:Antineoplastic Agents, Phytogenic / Q000008:administration & dosage / Q000494:pharmacology / Q000627:therapeutic use; D000971:Antineoplastic Combined Chemotherapy Protocols / Q000008:administration & dosage / Q000494:pharmacology* / Q000627:therapeutic use; D002292:Carcinoma, Renal Cell / Q000188:drug therapy / Q000473:pathology; D002455:Cell Division / Q000187:drug effects; D003841:Deoxycytidine / Q000008:administration & dosage / Q000031:analogs & derivatives* / Q000494:pharmacology / Q000627:therapeutic use; D004305:Dose-Response Relationship, Drug; D004347:Drug Interactions; D019008:Drug Resistance, Neoplasm; D006801:Humans; D007372:Interferons / Q000008:administration & dosage / Q000494:pharmacology* / Q000627:therapeutic use; D007680:Kidney Neoplasms / Q000188:drug therapy / Q000473:pathology; D013997:Time Factors; D016896:Treatment Outcome; D014407:Tumor Cells, Cultured / Q000166:cytology / Q000187:drug effects; D014747:Vinblastine / Q000008:administration & dosage / Q000494:pharmacology / Q000627:therapeutic use; D000093542:Gemcitabine
chemical_list: D000970:Antineoplastic Agents; D000972:Antineoplastic Agents, Phytogenic; D003841:Deoxycytidine; D014747:Vinblastine; D007372:Interferons; D000093542:Gemcitabine