title: Enhancement of chromosomal aberrations in tumor cells with a non-labeled Cu-PTSM and irradiation with Cu K-shell monochromatic X rays.
abstract: This study aims to clarify the enhancement effect on chromosomal aberrations via selective energy absorption by Cu atoms in cultured bone cancer cells with non-labelled Cu-pyruvaldehyde-bis(N(4)-methylsemicarbazone) (Cu-PTSM) and monochromatic X rays. The X rays having the energy of the Cu K-shell absorption edge arising from synchrotron radiation (KEK-PF) was used as radiation source. Cu-PTSM labelled with copper radionuclides has been developed for medical imaging using positron emission tomography (PET). Evidence clearly showed that the absorption of X rays in the Cu K-shell caused this enhancement. After cells were treated with 1000 nM Cu-PTSM, the enhancement ratio of the initial yield of isochromatid breaks caused by CuK-H X-ray irradiation to that by 200 kV(p) X rays was approximately 2.8. About 5.6 times of the remaining isochromatid breaks were observed at 4 h in Cu-PTSM treated samples irradiated with CuK-H X rays comparing to that with 200 kV(p) X rays. In this study, uniqueness in physical property such as Cu atom K-shell ionisation was applied for the enhancement of biological effects in cancer cells.
authors.affiliation: Physics Department, Division of Natural Sciences, International Christian University, Mitaka-shi, Tokyo 181-8585, Japan. kaoru@icu.ac.jp
authors.forename: Kaoru
authors.initials: K
authors.lastname: Takakura
authors.forename: Satoshi
authors.initials: S
authors.lastname: Yaguchi
authors.forename: Yuichi
authors.initials: Y
authors.lastname: Kanansugi
authors.forename: Katsumi
authors.initials: K
authors.lastname: Kobayashi
authors.forename: Ryuichi
authors.initials: R
authors.lastname: Okayasu
authors.forename: Yasuhisa
authors.initials: Y
authors.lastname: Fujibayashi
mesh_terms: D000293:Adolescent; D001859:Bone Neoplasms / Q000473:pathology / Q000503:physiopathology*; D002869:Chromosome Aberrations / Q000528:radiation effects*; D002875:Chromosomes / Q000235:genetics / Q000528:radiation effects; D003301:Copper Radioisotopes; D004273:DNA, Neoplasm / Q000235:genetics* / Q000528:radiation effects*; D004307:Dose-Response Relationship, Radiation; D005260:Female; D006801:Humans; D009942:Organometallic Compounds / Q000528:radiation effects*; D012516:Osteosarcoma / Q000473:pathology / Q000503:physiopathology*; D011829:Radiation Dosage; D013194:Staining and Labeling / Q000379:methods; D013882:Thiosemicarbazones / Q000528:radiation effects*; D014407:Tumor Cells, Cultured; D014965:X-Rays
chemical_list: D003301:Copper Radioisotopes; D004273:DNA, Neoplasm; D009942:Organometallic Compounds; D013882:Thiosemicarbazones; C052629:copper pyruvaldehyde bis(N(4)-methylthiosemicarbazone) complex