title: [In vitro study of radiation sensitizing effect of hydroxycamptothecin].
abstract: OBJECTIVE
  To study the radiation sensitizing effect of hydroxycamptothecin (HCPT) on human stomach adenocacinoma and nasopharyngeal carcinoma.
  
  
  METHODS
  Human stomach cancer cell line BGC823 and nasopharyngeal cancer cell line CNE-1 were treated in vitro with different doses of radiation alone or radiation followed by HCPT (2 micrograms/ml) for 4 h. Colony forming assay was used for survival fraction analysis. Single-hit multitarget model was used to plot survival curve.
  
  
  RESULTS
  The value of D0, Dq and N of BGC823 cells received radiation treatment alone was 1.17 Gy, 1.91 Gy and 5.14 respectively. That of BGC 823 cells received radiation plus HCPT was 0.95 Gy, 0.01 Gy and 1.01 respectively. The sensitization enhanecment (SER) ratio was 1.23 (1.17/0.95). Similar results were obtained for CNE-1 cells treated with radiation alone or in combination with HCPT, with an SER of 1.68.
  
  
  CONCLUSIONS
  HCPT has been shown a radiosensitizing effect in vitro on gastric and nasopharyngeal cancer cells.
authors.affiliation: Cancer Institute (Hospital), Chinese Academy of Medical Sciences, Peking Union Medical College, Beijing 100021, China.
authors.forename: L
authors.initials: L
authors.lastname: Wang
authors.forename: W
authors.initials: W
authors.lastname: Yang
mesh_terms: D000972:Antineoplastic Agents, Phytogenic / Q000494:pharmacology*; D002166:Camptothecin / Q000031:analogs & derivatives* / Q000494:pharmacology*; D002470:Cell Survival / Q000187:drug effects / Q000528:radiation effects; D006801:Humans; D011836:Radiation Tolerance / Q000187:drug effects*; D014407:Tumor Cells, Cultured; D014410:Tumor Stem Cell Assay
chemical_list: D000972:Antineoplastic Agents, Phytogenic; C028098:10-hydroxycamptothecin; D002166:Camptothecin