title: Detection of metastatic tumors after γ-irradiation using longitudinal molecular imaging and gene expression profiling of metastatic tumor nodules.
abstract: A few recent reports have indicated that metastatic growth of several human cancer cells could be promoted by radiotherapy. C6-L cells expressing the firefly luciferase (fLuc) gene were implanted subcutaneously into the right thigh of BALB/c nu/nu mice. C6-L xenograft mice were treated locally with 50-Gy γ-irradiation (γ-IR) in five 10-Gy fractions. Metastatic tumors were evaluated after γ-IR by imaging techniques. Total RNA from non-irradiated primary tumor (NRPT), γ-irradiated primary tumor (RPT), and three metastatic lung nodule was isolated and analyzed by microarray. Metastatic lung nodules were detected by BLI and PET/CT after 6-9 weeks of γ-IR in 6 (17.1%) of the 35 mice. The images clearly demonstrated high [18F]FLT and [18F]FDG uptake into metastatic lung nodules. Whole mRNA expression patterns were analyzed by microarray to elucidate the changes among NRPT, RPT and metastatic lung nodules after γ-IR. In particular, expression changes in the cancer stem cell markers were highly significant in RPT. We observed the metastatic tumors after γ-IR in a tumor-bearing animal model using molecular imaging methods and analyzed the gene expression profile to elucidate genetic changes after γ-IR.
authors.affiliation: Molecular Imaging Research Center, Korea Institute of Radiological and Medical Sciences (KIRAMS), Seoul 139-706, Republic of Korea.
authors.forename: Su Jin
authors.initials: SJ
authors.lastname: Jang
authors.affiliation: Molecular Imaging Research Center, Korea Institute of Radiological and Medical Sciences (KIRAMS), Seoul 139-706, Republic of Korea.
authors.forename: Joo Hyun
authors.initials: JH
authors.lastname: Kang
authors.affiliation: Molecular Imaging Research Center, Korea Institute of Radiological and Medical Sciences (KIRAMS), Seoul 139-706, Republic of Korea.
authors.forename: Yong Jin
authors.initials: YJ
authors.lastname: Lee
authors.affiliation: Molecular Imaging Research Center, Korea Institute of Radiological and Medical Sciences (KIRAMS), Seoul 139-706, Republic of Korea.
authors.forename: Kwang Il
authors.initials: KI
authors.lastname: Kim
authors.affiliation: Molecular Imaging Research Center, Korea Institute of Radiological and Medical Sciences (KIRAMS), Seoul 139-706, Republic of Korea.
authors.forename: Tae Sup
authors.initials: TS
authors.lastname: Lee
authors.affiliation: Department of Nuclear Medicine, Korea University Anam Hospital, Korea University College of Medicine, Seoul 136-705, Republic of Korea.
authors.forename: Jae Gol
authors.initials: JG
authors.lastname: Choe
authors.affiliation: Molecular Imaging Research Center, Korea Institute of Radiological and Medical Sciences (KIRAMS), Seoul 139-706, Republic of Korea.
authors.forename: Sang Moo
authors.initials: SM
authors.lastname: Lim
mesh_terms: D000818:Animals; D017209:Apoptosis / Q000528:radiation effects; D045744:Cell Line, Tumor; D049109:Cell Proliferation / Q000528:radiation effects; D005720:Gamma Rays; D005910:Glioma / Q000000981:diagnostic imaging / Q000473:pathology*; D006801:Humans; D051379:Mice; D009362:Neoplasm Metastasis; D009381:Neoplasms, Radiation-Induced / Q000473:pathology* / Q000556:secondary; D014411:Neoplastic Stem Cells / Q000473:pathology* / Q000528:radiation effects; D049268:Positron-Emission Tomography; D051381:Rats; D023041:Xenograft Model Antitumor Assays