title: Reovirus oncolysis of human breast cancer.
abstract: We have previously shown that human reovirus replication is restricted to cells with an activated Ras pathway, and that reovirus could be used as an effective oncolytic agent against human glioblastoma xenografts. This study examines in more detail the feasibility of reovirus as a therapeutic for breast cancer, a subset of cancer in which direct activating mutations in the ras proto-oncogene are rare, and yet where unregulated stimulation of Ras signaling pathways is important in the pathogenesis of the disease. We demonstrate herein the efficient lysis of breast tumor-derived cell lines by the virus, whereas normal breast cells resist infection in vitro. In vivo studies of reovirus breast cancer therapy reveal that viral administration could cause tumor regression in an MDA-MB-435S mammary fat pad model in severe combined immunodeficient mice. Reovirus could also effect regression of tumors remote from the injection site in an MDA-MB-468 bilateral tumor model, raising the possibility of systemic therapy of breast cancer by the oncolytic agent. Finally, the ability of reovirus to act against primary breast tumor samples not propagated as cell lines was evaluated; we found that reovirus could indeed replicate in ex vivo surgical specimens. Overall, reovirus shows promise as a potential breast cancer therapeutic.
authors.affiliation: Cancer Biology Research Group, Faculty of Medicine, University of Calgary, Calgary, Alberta, T2N 4N1 Canada.
authors.forename: Kara L
authors.initials: KL
authors.lastname: Norman
authors.forename: Matthew C
authors.initials: MC
authors.lastname: Coffey
authors.forename: Kensuke
authors.initials: K
authors.lastname: Hirasawa
authors.forename: Douglas J
authors.initials: DJ
authors.lastname: Demetrick
authors.forename: Sandra G
authors.initials: SG
authors.lastname: Nishikawa
authors.forename: Lisa M
authors.initials: LM
authors.lastname: DiFrancesco
authors.forename: James E
authors.initials: JE
authors.lastname: Strong
authors.forename: Patrick W K
authors.initials: PW
authors.lastname: Lee
mesh_terms: D000818:Animals; D001691:Biological Therapy; D001943:Breast Neoplasms / Q000235:genetics / Q000473:pathology / Q000628:therapy*; D016923:Cell Death / Q000235:genetics; D005260:Female; D011905:Genes, ras; D015316:Genetic Therapy; D006801:Humans; D051379:Mice; D016513:Mice, SCID; D009368:Neoplasm Transplantation; D000090063:Proto-Oncogene Mas; D012087:Reoviridae / Q000502:physiology*; D014183:Transplantation, Heterologous; D014407:Tumor Cells, Cultured; D014779:Virus Replication / Q000235:genetics