title: In vivo interferon regulatory factor 3 tumor suppressor activity in B16 melanoma tumors.
abstract: Delivery of transcription factors to cancer cells to reprogram gene expression may represent a novel strategy to augment the production of immune stimulatory cytokines and trigger a more potent antitumor response. In the present study, a bicistronic retroviral vector (AP2) was used to transduce B16-F0 melanoma cells with IFN regulatory factor (IRF)-3, which has been shown to activate type I IFN genes (IFN-beta and IFN-alpha) as well as other cytokines. Gene-modified B16 melanoma cells were inoculated s.c. into C57BL/6 syngeneic mice. In animals receiving IRF-3 B16 melanoma cells, tumors grew at a 4- to 5-fold reduced rate, and tumors that developed from these mice had a moderate-to-dense infiltration of inflammatory cells, whereas only low levels of lymphocyte infiltration were observed in mock-transduced B16 tumors. Furthermore, tumor growth was not inhibited in severe-combined immunodeficient mice after inoculation of IRF-3-expressing B16 cells, which suggested that IRF-3-mediated antitumor responses were dependent on a functional adaptive lymphocyte response. Interestingly, these in vivo effects on tumor growth correlated with higher mRNA expression of chemokines such as MIP-1beta, RANTES, and IP-10, as well as dramatic increases in vitro in the inducibility of cytokine mRNA such as IFN-beta, TNF-alpha and interleukin 6. Our results demonstrate that with weakly antigenic tumors such as B16 melanoma, IRF-3 gene transfer can mediate important antitumor responses. These findings suggest a novel role for IRF-3 as a potential molecular target for gene therapy of cancer.
authors.affiliation: Terry Fox Molecular Oncology Group, Lady Davis Institute-Jewish General Hospital, 3755 Cote-Ste.-Catherine Road, Montreal, Quebec H3T-1E2, Canada.
authors.forename: Delphine
authors.initials: D
authors.lastname: Duguay
authors.forename: François
authors.initials: F
authors.lastname: Mercier
authors.forename: John
authors.initials: J
authors.lastname: Stagg
authors.forename: Daniel
authors.initials: D
authors.lastname: Martineau
authors.forename: Jonathan
authors.initials: J
authors.lastname: Bramson
authors.forename: Marc
authors.initials: M
authors.lastname: Servant
authors.forename: Rongtuan
authors.initials: R
authors.lastname: Lin
authors.forename: Jacques
authors.initials: J
authors.lastname: Galipeau
authors.forename: John
authors.initials: J
authors.lastname: Hiscott
mesh_terms: D000818:Animals; D002455:Cell Division / Q000235:genetics / Q000276:immunology; D018925:Chemokines / Q000096:biosynthesis / Q000235:genetics / Q000276:immunology; D016207:Cytokines / Q000096:biosynthesis / Q000235:genetics / Q000276:immunology; D004268:DNA-Binding Proteins / Q000235:genetics* / Q000276:immunology*; D015316:Genetic Therapy / Q000379:methods; D005822:Genetic Vectors / Q000235:genetics; D050838:Interferon Regulatory Factor-3; D008546:Melanoma, Experimental / Q000235:genetics / Q000276:immunology* / Q000473:pathology / Q000628:therapy; D051379:Mice; D008810:Mice, Inbred C57BL; D012333:RNA, Messenger / Q000096:biosynthesis / Q000235:genetics; D012190:Retroviridae / Q000235:genetics; D014157:Transcription Factors / Q000235:genetics* / Q000276:immunology*; D014161:Transduction, Genetic
chemical_list: D018925:Chemokines; D016207:Cytokines; D004268:DNA-Binding Proteins; D050838:Interferon Regulatory Factor-3; C494233:Irf3 protein, mouse; D012333:RNA, Messenger; D014157:Transcription Factors