title: [The effect of small GTPase Cdc42 on the multidrug resistance of oxaliplatin-resistant colon cancer cell lines].
abstract: OBJECTIVE
  To determine the effect of cell division cycle42 (Cdc42) on the multidrug resistance of oxaliplatin-resistant human colon cancer cells.
  
  
  METHODS
  The protein expression levels of Cdc42 in oxaliplatin-resistant colon cancer cells and parental cells were examined with Western blot. pDEST26-His-Cdc42 was transfected by lipofectamine 2000 into SW480 and Colo320 cells with low expression of Cdc42. Cdc42 siRNA was transfected by lipofectamine 2000 into SW480/L-OHP and Colo320/L-OHP cells with high expression of Cdc42. The expression of Cdc42 in these cell lines were examined by Western blot and RT-PCR 48 hours after transfection. The sensitivity of colon cancer cells to antitumor drugs was evaluated using CCK-8 assay. The concentration of each drug that caused a 50% reduction in the numbers of cells (IC50) was calculated. The expression of P-gp, MRP1 in SW480/Cdc42 and Colo320/ Cdc42 cells were examined with Western blot.
  
  
  RESULTS
  Cdc42 was over-expressed in the SW480/L-OHP and Colo320/L-OHP cell lines. Over-expression of Cdc42 significantly enhanced the resistance of colon cancer cells to multiple antitumor drugs and up-regulated the expression of P-gp and MRP1.
  
  
  CONCLUSIONS
  Cdc42 enhances the resistance of colon cancer cells to several antitumor drugs. It might become a potential target for reversing multidrug resistance of colon cancer.
authors.affiliation: Department of Abdominal Cancer, West China Hospital, Sichuan University, Chengdu 610041, China.
authors.forename: Nan-Jing
authors.initials: NJ
authors.lastname: Li
authors.forename: Zhen
authors.initials: Z
authors.lastname: Liu
authors.forename: You
authors.initials: Y
authors.lastname: Zhang
authors.forename: Cai-Xia
authors.initials: CX
authors.lastname: Yue
authors.forename: Wen
authors.initials: W
authors.lastname: Wei
authors.forename: Li-Lan
authors.initials: LL
authors.lastname: Li
authors.forename: Qiu-Lin
authors.initials: QL
authors.lastname: Tang
authors.forename: Feng
authors.initials: F
authors.lastname: Bi
mesh_terms: D000970:Antineoplastic Agents / Q000494:pharmacology; D045744:Cell Line, Tumor; D003110:Colonic Neoplasms / Q000378:metabolism / Q000473:pathology*; D018432:Drug Resistance, Multiple; D019008:Drug Resistance, Neoplasm; D006801:Humans; D009944:Organoplatinum Compounds / Q000494:pharmacology*; D000077150:Oxaliplatin; D020764:cdc42 GTP-Binding Protein / Q000235:genetics / Q000378:metabolism*
chemical_list: D000970:Antineoplastic Agents; D009944:Organoplatinum Compounds; D000077150:Oxaliplatin; D020764:cdc42 GTP-Binding Protein