title: Modulation of cisplatin sensitivity and accumulation by interferon alpha-2A in human squamous carcinoma cell lines.
abstract: This study was undertaken to elucidate the mechanism(s) of potentiation of cisplatin (CDDP) cytotoxicity by interferon alpha-2a (IFN alpha-2a) in human squamous carcinoma cell lines SCC-25 and SCC-4. IFN alpha-2a treatment significantly increased the cytotoxicity of CDDP in both cell lines in a dose-dependent manner. In SCC-25 cells, the cytotoxicity of CDDP was increased by about 2- and 4-fold, respectively, by treating the cells with 400 and 800 IU/ml IFN alpha-2a. Sensitivity of SCC-4 cells to CDDP was increased by about 3- and 7-fold, respectively, by 400 and 800 IU/ml IFN alpha-2a treatment. Drug uptake experiments revealed approximately 1.4- to 5-fold higher platinum accumulation in IFN alpha-2a-treated cells as compared to respective controls. Cellular levels of glutathione (GSH) and GSH transferase, which have been suggested to be important determinants of tumor cell sensitivity to CDDP, were not altered by IFN alpha-2a treatment in either of the cell lines. Northern blot analysis showed a moderate increase (about 30-40%) in the level of MT-IIA mRNA by IFN alpha-2a treatment in these cells. Our results suggest that IFN alpha-2a-mediated sensitization of SCC-25 and SCC-4 cell lines to CDDP in vitro may be due to an increase in intracellular platinum accumulation.
authors.affiliation: Mercy Cancer Institute, Mercy Hospital, Pittsburgh, PA 15219, USA.
authors.forename: V
authors.initials: V
authors.lastname: Gupta
authors.forename: J P
authors.initials: JP
authors.lastname: Jani
authors.forename: E O
authors.initials: EO
authors.lastname: Emerson
authors.forename: B H
authors.initials: BH
authors.lastname: Xu
authors.forename: D
authors.initials: D
authors.lastname: Scalamogna
authors.forename: H
authors.initials: H
authors.lastname: Xia
authors.forename: A
authors.initials: A
authors.lastname: Katoh
authors.forename: H A
authors.initials: HA
authors.lastname: Zaren
authors.forename: S V
authors.initials: SV
authors.lastname: Singh
mesh_terms: D000970:Antineoplastic Agents / Q000494:pharmacology*; D002294:Carcinoma, Squamous Cell / Q000378:metabolism / Q000473:pathology*; D002470:Cell Survival / Q000187:drug effects; D002945:Cisplatin / Q000493:pharmacokinetics / Q000494:pharmacology*; D005978:Glutathione / Q000032:analysis; D005982:Glutathione Transferase / Q000378:metabolism; D006801:Humans; D000077190:Interferon alpha-2; D016898:Interferon-alpha / Q000494:pharmacology*; D008668:Metallothionein / Q000235:genetics; D012333:RNA, Messenger / Q000032:analysis; D011994:Recombinant Proteins; D014407:Tumor Cells, Cultured
chemical_list: D000970:Antineoplastic Agents; D000077190:Interferon alpha-2; D016898:Interferon-alpha; D012333:RNA, Messenger; D011994:Recombinant Proteins; D008668:Metallothionein; D005982:Glutathione Transferase; D005978:Glutathione; D002945:Cisplatin