title: Small interfering RNA (siRNA)-mediated silencing of the M2 subunit of ribonucleotide reductase: a novel therapeutic strategy in ovarian cancer.
abstract: OBJECTIVE
  To investigate the effects of small interfering RNA (siRNA)-mediated silencing of the ribonucleotide reductase M2 subunit (RRM2) on the apoptosis and the drug sensitivity of cisplatin-resistant SKOV3/DDP cells.
  
  
  METHODS
  Small interfering RNA transfection was mediated by lipofectamine 2000 to silence RRM2 gene. Messenger RNA (mRNA), and protein expression levels of RRM2 were evaluated by real-time polymerase chain reaction and Western blot after transfection. The cell growth inhibition rate was evaluated by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide. The cellular apoptosis and cycling was identified by flow cytometry (FCM).
  
  
  RESULTS
  The messenger RNA and protein expression levels of RRM2 markedly decreased after the RRM2 siRNA transfection. The half inhibition concentration of cisplatin in RRM2-RNA interference cells (interference group) was lower than that in RRM2-negative cells (noninterference group) and the SKOV3/DDP cells (blank control group) (P = 0.032). Small interfering RNA-mediated inhibition of RRM2 effectively induced G1/S-phase cell cycle arrest and increased drug (gemcitabine and cisplatin)-induced apoptotic fraction at 72 hours ( (96% ± 3.0)%) after transfection (P < 0.05).
  
  
  CONCLUSIONS
  Small interfering RNA-mediated RRM2 knockdown significantly reversed SKOV3/DDP cell resistance to cisplatin. RNA interference technology combined with gemcitabine and cisplatin can effectively improve the apoptosis rate of the cisplatin-resistant ovarian cancer cell, which is expected to become the first-line treatment options for the cisplatin-resistant ovarian cancer.
authors: Qingdao University, Qingdao, China.
authors: Meng
authors: M
authors: Zhang
authors: Jing
authors: J
authors: Wang
authors: RuYong
authors: R
authors: Yao
authors: LiMing
authors: L
authors: Wang
mesh_terms: D017209:Apoptosis / Q000235:genetics; D002277:Carcinoma / Q000628:therapy*; D002453:Cell Cycle / Q000235:genetics; D045744:Cell Line, Tumor; D002945:Cisplatin; D019008:Drug Resistance, Neoplasm; D005260:Female; D020868:Gene Silencing; D015316:Genetic Therapy; D006801:Humans; D010051:Ovarian Neoplasms / Q000628:therapy*; D034741:RNA, Small Interfering / Q000627:therapeutic use*; D012262:Ribonucleoside Diphosphate Reductase / Q000037:antagonists & inhibitors* / Q000235:genetics*
chemical_list: D034741:RNA, Small Interfering; C093713:ribonucleotide reductase M2; D012262:Ribonucleoside Diphosphate Reductase; D002945:Cisplatin