title: [5-aza-2'-deoxycytidine suppresses the growth of human lung adenocarcinoma cells in nude mouse xenograft models and its effect on methylation status and expression of TFPI-2 gene].
abstract: OBJECTIVE
  To investigate the inhibitory effect of classic demethylating drug 5-aza-2'-deoxycytidine (5-Aza-CdR) on the growth of human lung adenocarcinoma cells in nude mouse xenograft models, and to observe its effect on methylation status and expression of TFPI-2 gene in the nude mouse xenograft tissues.
  
  
  METHODS
  The nude mouse xenograft model was established by subcutaneous inoculation of human lung adenocarcinoma A549 cells. According to different doses of 5-Aza-CdR, the tumor-bearing nude mice were randomly divided into experimental groups (0.5 mg/kg group, 1 mg/kg group, 2 mg/kg group) and control group (0 mg/kg group). The tumor growth in the nude mice was observed. The methylation status and the expression of TFPI-2 gene mRNA and protein were detected by methylation specific polymerase chain reaction, real-time fluorescent quantitative polymerase chain reaction and Western blot assay.
  
  
  RESULTS
  The nude mice were euthanized at 28 days after intraperitoneal injection of 5-Aza-CdR. The body weight of tumor-bearing nude mice was (27.12 ± 0.38) g in the 0 mg/kg group, (26.80 ± 0.18) g in the 0.5 mg/kg group, (26.67 ± 0.28) g in the 1 mg/kg group, and (26.50 ± 0.26) g in the 2 mg/kg group, showing no significant difference among them (P > 0.05). The volume of xenograft tumors in the 0 mg/kg group was (709.22 ± 2.87)mm³, (400.67 ± 2.68)mm³ in the 0.5 mg/kg group, (285.71 ± 2.91)mm³ in the 1 mg/kg group, and (230.44 ± 3.15)mm³ in the 2 mg/kg group, showing a significant difference (P < 0.05). There were complete methylation of TFPI-2 gene in the 0 mg/kg group, incomplete methylation in the 0.5 and 1 mg/kg groups, and unmethylation in the 2 mg/kg group. The relative mRNA level in the 0, 0.5, 1, 2 mg/kg groups were 1.00 ± 0.00, 1.67 ± 0.07, 3.40 ± 0.24, and 5.55 ± 0.61, respectively (P < 0.05). The relative expression level of TFPI-2 protein in the 0, 0.5, 1, 2 mg/kg groups was 0.18 ± 0.02, 0.36 ± 0.01, 0.64 ± 0.02, and 0.81 ± 0.20, respectively (P < 0.05).
  
  
  CONCLUSIONS
  5-Aza-CdR suppresses the tumor growth of human lung adenocarcinoma cells in nude mouse xenograft models, and induces expression of TFPI-2 gene in the xenograft tumor cells. The mechanism might be that 5-Aza-CdR induces re-expression of demethylated TFPI-2 gene by demethylation, and thus inhibits the growth and proliferation of human lung adenocarcinoma cells.
authors.affiliation: Diagnosis and Treatment Center of Thoracic and Lung Cancers, the First People's Hospital of Chenzhou City, Chenzhou 423000, China.
authors.forename: Jiangshui
authors.initials: J
authors.lastname: Liang
authors.forename: Guilin
authors.initials: G
authors.lastname: Yin
authors.affiliation: Email: dyqwhzyy@163.com.
authors.forename: Yongqiang
authors.initials: Y
authors.lastname: Dong
authors.forename: Zhongsha
authors.initials: Z
authors.lastname: Ma
authors.forename: Yuehua
authors.initials: Y
authors.lastname: Xiao
authors.forename: Tao
authors.initials: T
authors.lastname: Ji
mesh_terms: D000230:Adenocarcinoma / Q000188:drug therapy* / Q000473:pathology; D000077192:Adenocarcinoma of Lung; D000818:Animals; D000964:Antimetabolites, Antineoplastic / Q000494:pharmacology*; D001374:Azacitidine / Q000031:analogs & derivatives* / Q000494:pharmacology; D049109:Cell Proliferation / Q000187:drug effects; D019175:DNA Methylation; D000077209:Decitabine; D004195:Disease Models, Animal; D015972:Gene Expression Regulation, Neoplastic; D006023:Glycoproteins / Q000235:genetics*; D064593:Heterografts; D006801:Humans; D008175:Lung Neoplasms / Q000188:drug therapy* / Q000473:pathology; D051379:Mice; D008819:Mice, Nude; D012333:RNA, Messenger / Q000378:metabolism; D011897:Random Allocation
chemical_list: D000964:Antimetabolites, Antineoplastic; D006023:Glycoproteins; D012333:RNA, Messenger; C021240:tissue-factor-pathway inhibitor 2; D000077209:Decitabine; D001374:Azacitidine