title: Recruitment of circulating breast cancer cells is stimulated by radiotherapy.
abstract: Radiotherapy (RT) is a localized therapy that is highly effective in killing primary tumor cells located within the field of the radiation beam. We present evidence that irradiation of breast tumors can attract migrating breast cancer cells. Granulocyte-macrophage colony stimulating factor (GM-CSF) produced by tumor cells in response to radiation stimulates the recruitment of migrating tumor cells to irradiated tumors, suggesting a mechanism of tumor recurrence after radiation facilitated by transit of unirradiated, viable circulating tumor cells to irradiated tumors. Data supporting this hypothesis are presented through in vitro invasion assays and in vivo orthotopic models of breast cancer. Our work provides a mechanism for tumor recurrence in which RT attracts cells outside the radiation field to migrate to the site of treatment.
authors.affiliation: Division of Radiation and Cancer Biology, Department of Radiation Oncology, Molecular Imaging Program at Stanford, Stanford University, Stanford, CA 94305, USA.
authors.forename: Marta
authors.initials: M
authors.lastname: Vilalta
authors.affiliation: Division of Radiation and Cancer Biology, Department of Radiation Oncology, Molecular Imaging Program at Stanford, Stanford University, Stanford, CA 94305, USA.
authors.forename: Marjan
authors.initials: M
authors.lastname: Rafat
authors.affiliation: Division of Radiation and Cancer Biology, Department of Radiation Oncology, Molecular Imaging Program at Stanford, Stanford University, Stanford, CA 94305, USA.
authors.forename: Amato J
authors.initials: AJ
authors.lastname: Giaccia
authors.affiliation: Division of Radiation and Cancer Biology, Department of Radiation Oncology, Molecular Imaging Program at Stanford, Stanford University, Stanford, CA 94305, USA; Division of Radiation Physics, Department of Radiation Oncology, Molecular Imaging Program at Stanford, Stanford University, Stanford, CA 94305, USA. Electronic address: egraves@stanford.edu.
authors.forename: Edward E
authors.initials: EE
authors.lastname: Graves
mesh_terms: D000818:Animals; D001943:Breast Neoplasms / Q000473:pathology* / Q000532:radiotherapy; D045744:Cell Line, Tumor; D016178:Granulocyte-Macrophage Colony-Stimulating Factor / Q000378:metabolism; D006801:Humans; D051379:Mice; D009360:Neoplastic Cells, Circulating / Q000528:radiation effects*
chemical_list: D016178:Granulocyte-Macrophage Colony-Stimulating Factor