title: Etoposide sensitizes CT26 colorectal adenocarcinoma to radiation therapy in BALB/c mice.
abstract: OBJECTIVE
  To investigate the combined effect of etoposide and radiation on CT26 colorectal adenocarcinoma implanted into BALB/c mice.
  
  
  METHODS
  We evaluated the radiosensitizing effect of etoposide on CT26 colorectal adenocarcinoma in a syngeneic animal model. BALB/c mice were subcutaneously implanted with CT26 cells and divided into four groups: control (intra-peritoneal salineX2) group, etoposide (5 mg/kg intra-peritoneallyX2) group, radiation therapy (RT 5 GyX2 fractions) group, and combination therapy with etoposide (5 mg/kg intra-peritoneally 1 h before radiation) group.
  
  
  RESULTS
  Tumor growth was significantly inhibited by RT and combination therapy. The effect of combination therapy was better than that of RT. No significant changes were noted in body weight, plasma alanine aminotransferase, or creatinine in any group. The leukocyte count significantly but transiently decreased in the RT and combination therapy groups, but not in the etoposide and control groups. There was no skin change or hair loss in the RT and combination therapy groups.
  
  
  CONCLUSIONS
  Etoposide can sensitize CT26 colorectal adenocarcinoma in BALB/c mice to RT without significant toxicity.
authors.affiliation: Department of Radiation Oncology, Mackay Memorial Hospital, No. 92 Section 2 Chung San North Road, Taipei 104, Taiwan, China.
authors.forename: Chia-Yuan
authors.initials: CY
authors.lastname: Liu
authors.forename: Hui-Fen
authors.initials: HF
authors.lastname: Liao
authors.forename: Tsang-En
authors.initials: TE
authors.lastname: Wang
authors.forename: Shee-Chan
authors.initials: SC
authors.lastname: Lin
authors.forename: Shou-Chuan
authors.initials: SC
authors.lastname: Shih
authors.forename: Wen-Hsuing
authors.initials: WH
authors.lastname: Chang
authors.forename: Yuh-Cheng
authors.initials: YC
authors.lastname: Yang
authors.forename: Ching-Chung
authors.initials: CC
authors.lastname: Lin
authors.forename: Yu-Jen
authors.initials: YJ
authors.lastname: Chen
mesh_terms: D000230:Adenocarcinoma / Q000188:drug therapy / Q000473:pathology / Q000532:radiotherapy*; D000818:Animals; D000972:Antineoplastic Agents, Phytogenic / Q000627:therapeutic use; D015179:Colorectal Neoplasms / Q000188:drug therapy / Q000473:pathology / Q000532:radiotherapy*; D003131:Combined Modality Therapy; D004195:Disease Models, Animal; D005047:Etoposide / Q000627:therapeutic use*; D051379:Mice; D008807:Mice, Inbred BALB C; D011878:Radiotherapy / Q000379:methods*
chemical_list: D000972:Antineoplastic Agents, Phytogenic; D005047:Etoposide