title: [siRNA-mediated CDK6 knockdown suppresses nasopharyngeal carcinoma cell growth and cell cycle transition in vitro].
abstract: OBJECTIVE
  To assess the effect of small interfering RNA (siRNA)-mediated suppression of CDK6 expression on the proliferation and cell cycles of nasopharyngeal carcinoma (NPC) cells in vitro.
  
  
  METHODS
  QRT-PCR was used to examine the differential expression of CDK6 in 30 NPC tissues and 18 normal nasopharyngeal tissues. A siRNA targeting CDK6 was transfected in NPC CNE2 cells, and MTT assay and flow cytometry were used to analyze the changes in cell proliferation and cell cycle distribution. Western blotting was used to examine the expressions of the cell cycle-related factors.
  
  
  RESULTS
  Compared with normal nasopharyngeal tissues, NPC tissues showed an increased expression of CDK6 mRNA. Knocking down CDK6 expression obviously inhibited tumor cell growth and cell cycle transition from G1 to S phase and caused reduced expressions of CDK4, CCND1, and E2F1 and enhanced expression of the tumor suppressor p21.
  
  
  CONCLUSIONS
  NPC tissues overexpress CDK6. Knocking down CDK6 expression inhibits the growth and cell cycle transition of NPC cells in vitro by inhibiting the expressions of CDK4, CCND1, and E2F1 and upregulating tumor suppressor p21 expression.
authors: Department of Otorhinolaryngology, Affiliated Hospital of Youjiang Medical University for Nationalities, Baise 533000, China. E-mail: yyfyentlxp@163.com.
authors: Xiaopeng
authors: X
authors: Luo
authors: Qiong
authors: Q
authors: Xia
authors: Jixin
authors: J
authors: Qin
authors: Yongzhi
authors: Y
authors: Huang
authors: Jin
authors: J
authors: Liu
authors: Ying
authors: Y
authors: Wang
authors: Huaifei
authors: H
authors: Wang
authors: Jiajun
authors: J
authors: Chen
mesh_terms: D002277:Carcinoma; D002453:Cell Cycle; D045744:Cell Line, Tumor; D049109:Cell Proliferation; D019938:Cyclin D1 / Q000378:metabolism; D051358:Cyclin-Dependent Kinase 4 / Q000378:metabolism; D051361:Cyclin-Dependent Kinase 6 / Q000235:genetics*; D050759:Cyclin-Dependent Kinase Inhibitor p21 / Q000378:metabolism; D050687:E2F1 Transcription Factor / Q000378:metabolism; D015972:Gene Expression Regulation, Neoplastic; D055785:Gene Knockdown Techniques; D006801:Humans; D000077274:Nasopharyngeal Carcinoma; D009303:Nasopharyngeal Neoplasms / Q000473:pathology*; D012333:RNA, Messenger; D034741:RNA, Small Interfering; D014162:Transfection; D015854:Up-Regulation
chemical_list: C530104:CCND1 protein, human; C493956:CDKN1A protein, human; D050759:Cyclin-Dependent Kinase Inhibitor p21; D050687:E2F1 Transcription Factor; C493753:E2F1 protein, human; D012333:RNA, Messenger; D034741:RNA, Small Interfering; D019938:Cyclin D1; C495900:CDK4 protein, human; C495911:CDK6 protein, human; D051358:Cyclin-Dependent Kinase 4; D051361:Cyclin-Dependent Kinase 6