title: Synergistic therapeutic effect of arsenic trioxide and radiotherapy in BALB/C nude mice bearing nasopharyngeal carcinoma xenografts.
abstract: It has been shown that arsenic trioxide (ATO) induced apoptosis in human nasopharyngeal carcinoma cells and inhibited the growth of nasopharyngeal carcinoma xenografts (NPCX) in nude mice.
  
  
  OBJECTIVE
  The present study was designed to determine whether ATO at the non-toxic dose level could potentiate the therapeutic effectiveness of radiation therapy in nasopharyngeal carcinoma, using a BALB/C nude mouse xenograft model.
  
  
  METHODS
  The mice bearing NPCX were treated with radiation alone (2, 4, and 6 Gy), ATO alone (4 mg/kg/day x 6 days), and ATO plus radiation at the same dosage levels. Time of tumor growth delay (defined as the time necessary for the tumor to grow four-fold of its initial volume after, compared with untreated tumors) and toxic effects were determined.
  
  
  RESULTS
  The low dose ATO alone has no pronounced effects on tumor growth delay compared to untreated control. However, compared with radiation alone, the combined regimen delayed the tumor growth by 2-10 days and had no significant toxic effects such as the liver function damage.
  
  
  CONCLUSIONS
  Combination of ATO at non-toxic dose level and radiation has synergistic effects on tumor growth inhibition in vivo and is well tolerated.
authors: Laboratory of Cancer Research, Tumor Hospital, Shantou University Medical College, Shantou, China.
authors: L X
authors: LX
authors: Xie
authors: X H
authors: XH
authors: Lin
authors: D R
authors: DR
authors: Li
authors: J Y
authors: JY
authors: Chen
authors: C Q
authors: CQ
authors: Hong
authors: C W
authors: CW
authors: Du
mesh_terms: D000818:Animals; D000970:Antineoplastic Agents / Q000627:therapeutic use*; D000077237:Arsenic Trioxide; D001152:Arsenicals / Q000627:therapeutic use*; D045744:Cell Line, Tumor; D003131:Combined Modality Therapy; D006801:Humans; D051379:Mice; D008807:Mice, Inbred BALB C; D016513:Mice, SCID; D009303:Nasopharyngeal Neoplasms / Q000188:drug therapy* / Q000532:radiotherapy*; D010087:Oxides / Q000627:therapeutic use*; D014183:Transplantation, Heterologous
chemical_list: D000970:Antineoplastic Agents; D001152:Arsenicals; D010087:Oxides; D000077237:Arsenic Trioxide