title: In vitro characterization of cells derived from chordoma cell line U-CH1 following treatment with X-rays, heavy ions and chemotherapeutic drugs.
abstract: BACKGROUND
  Chordoma, a rare cancer, is usually treated with surgery and/or radiation. However, very limited characterizations of chordoma cells are available due to a minimal availability (only two lines validated by now) and the extremely long doubling time. In order to overcome this situation, we successfully derived a cell line with a shorter doubling time from the first validated chordoma line U-CH1 and obtained invaluable cell biological data.
  
  
  METHODS
  After isolating a subpopulation of U-CH1 cells with a short doubling time (U-CH1-N), cell growth, cell cycle distribution, DNA content, chromosome number, p53 status, and cell survival were examined after exposure to X-rays, heavy ions, camptothecin, mitomycin C, cisplatin and bleocin. These data were compared with those of HeLa (cervical cancer) and U87-MG (glioblastoma) cells.
  
  
  RESULTS
  The cell doubling times for HeLa, U87-MG and U-CH1-N were approximately 18 h, 24 h and 3 days respectively. Heavy ion irradiation resulted in more efficient cell killing than x-rays in all three cell lines. Relative biological effectiveness (RBE) at 10% survival for U-CH1-N was about 2.45 for 70 keV/μm carbon and 3.86 for 200 keV/μm iron ions. Of the four chemicals, bleocin showed the most marked cytotoxic effect on U-CH1-N.
  
  
  CONCLUSIONS
  Our data provide the first comprehensive cellular characterization using cells of chordoma origin and furnish the biological basis for successful clinical results of chordoma treatment by heavy ions.
authors.affiliation: Research Center for Charged Particle Therapy, National Institute of Radiological Sciences, 4-9-1 Anagawa, Inage-ku, Chiba-shi, 263-8555 Japan.
authors.forename: Takamitsu A
authors.initials: TA
authors.lastname: Kato
authors.forename: Akihisa
authors.initials: A
authors.lastname: Tsuda
authors.forename: Mitsuru
authors.initials: M
authors.lastname: Uesaka
authors.forename: Akira
authors.initials: A
authors.lastname: Fujimori
authors.forename: Tadashi
authors.initials: T
authors.lastname: Kamada
authors.forename: Hirohiko
authors.initials: H
authors.lastname: Tsujii
authors.forename: Ryuichi
authors.initials: R
authors.lastname: Okayasu
mesh_terms: D000970:Antineoplastic Agents / Q000494:pharmacology*; D001859:Bone Neoplasms / Q000188:drug therapy* / Q000532:radiotherapy*; D002453:Cell Cycle; D045744:Cell Line, Tumor; D002817:Chordoma / Q000188:drug therapy* / Q000532:radiotherapy*; D002875:Chromosomes / Q000648:ultrastructure; D005434:Flow Cytometry; D006367:HeLa Cells; D006801:Humans; D066298:In Vitro Techniques; D007621:Karyotyping; D012062:Relative Biological Effectiveness; D015203:Reproducibility of Results; D013997:Time Factors; D016159:Tumor Suppressor Protein p53 / Q000096:biosynthesis; D014965:X-Rays
chemical_list: D000970:Antineoplastic Agents; C495901:TP53 protein, human; D016159:Tumor Suppressor Protein p53