title: Effects of gene silencing of CypB on gastric cancer cells.
abstract: OBJECTIVE
  To determine the effect of gene silencing of cyclophilin B (CypB) on growth and proliferation of gastric cancer cells.
  
  
  METHODS
  CypB siRNA lentivirus (LV-CypB-si) and control lentivirus (LV-si-con) were produced. CypB expression in gastric cancer cell lines was detected by Western blot. BGC823 and SGC7901 cells were chosen to be infected with LV-si-con and LV-CypB-si, and stable transfectants were isolated. The cell groups transfected with LV-CypB-siRNA, LV-siRNA-con and transfected no carrier were served as the experimental group, the implicit control group and the blank control group respectively. MTT and colony formation assays were used to examine the effect of CypB on the cell growth and proliferation in vitro. Cell cycle was analyzed with flow cytometry. The expression of VEGFR of BGC823-si and SGC7901-si was detected by Western blot.
  
  
  RESULTS
  Gene silencing of CypB can inhibit gastric cancer cell growth, proliferation, cell cycle progress and tumorigenesis. CypB expression level was obviously higher in SGC7901 and BGC823 than MKN28 and GES. These two cell lines were infected with LV-si-con and LV-CypB-si respectively. MTT and cloney formation assays showed a significantly decreased rate of cell proliferation from the forth day or the fifth day in cells transfected with LV-CypB-si (P<0.05). Down-regulation of CypB resulted in slightly decreased percentage of S phase and increased percentage of G1 (P<0.05). These findings indicated that CypB could promote the G1-S transition of gastric cancer cell. In addition, the expression of VEGF of BGC823 and SGC7901 transfected with CypB siRNA was reduced in comparison with the implicit control group and the blank control group.
  
  
  CONCLUSIONS
  Gene silencing of CypB decreases gastric cancer cells proliferation and in vivo tumorigenesis. These findings indiccate CypB could be a potential biomarker and therapeutic target for gastric cancer.
authors.affiliation: Department of Gastroenterology, Training Hospital Daqing Oil Feld General Hospital Affiliated to Qiqihar Medical School, Daqing 230600, China.
authors.forename: Feng
authors.initials: F
authors.lastname: Guo
authors.affiliation: Department of Gastroenterology, Training Hospital Daqing Oil Feld General Hospital Affiliated to Qiqihar Medical School, Daqing 230600, China.
authors.forename: Ying
authors.initials: Y
authors.lastname: Zhang
authors.affiliation: Department of Gastroenterology, Training Hospital Daqing Oil Feld General Hospital Affiliated to Qiqihar Medical School, Daqing 230600, China.
authors.forename: Chun-Na
authors.initials: CN
authors.lastname: Zhao
authors.affiliation: Department of Gastroenterology, Training Hospital Daqing Oil Feld General Hospital Affiliated to Qiqihar Medical School, Daqing 230600, China.
authors.forename: Lin
authors.initials: L
authors.lastname: Li
authors.affiliation: Department of Gastroenterology, Training Hospital Daqing Oil Feld General Hospital Affiliated to Qiqihar Medical School, Daqing 230600, China. Electronic address: panggang1978@163.com.
authors.forename: Yan-Jun
authors.initials: YJ
authors.lastname: Guo
keywords: CyclophilinB; Gastric cancer; Gene silencing