title: Adenovirus-mediated siRNA targeting Bcl-xL inhibits proliferation, reduces invasion and enhances radiosensitivity of human colorectal cancer cells.
abstract: BACKGROUND
  Bcl-xL, an important member of anti-apoptotic Bcl-2 family, plays critical roles in tumor progression and development. Previously, we have reported that overexpression of Bcl-xL was correlated with prognosis of colorectal cancer (CRC) patients. The aim of this study was to investigate the association of Bcl-xL expression with invasion and radiosensitivity of human CRC cells.
  
  
  METHODS
  RT-PCR and Western blot assays were performed to determine the expression of Bcl-xL mRNA and protein in CRC cells and normal human intestinal epithelial cell line. Then, adenovirus-mediated RNA interference technique was employed to inhibit the expression of Bcl-xL gene in CRC cells. The proliferation of CRC cells was analyzed by MTT and colony formation assay. The migration and invasion of CRC cells was determined by wound-healing and tranwell invasion assays. Additionally, the in vitro and in vivo radiosensitivity of CRC cells was determined by clonogenic cell survival assay and murine xnograft model, respectively.
  
  
  RESULTS
  The levels of Bcl-xL mRNA and protein expression were significantly higher in human CRC cells than in normal human intestinal epithelial cell line. Ad/shBcl-xL could significantly reduce the expression of Bcl-xL protein in CRC cells. Also, we showed that adenovirus-mediated siRNA targeting Bcl-xL could significantly inhibit proliferation and colony formation of CRC cells. Ad/shBcl-xL could significantly suppress migration and invasion of CRC cells. Moreover, Ad/shBcl-xL could enhance in vitro and in vivo radiosensitivity of CRC cells by increasing caspase-dependent apoptosis.
  
  
  CONCLUSIONS
  Targeting Bcl-xL will be a promising strategy to inhibit the metastatic potential and reverse the radioresistance of human CRC.
authors.affiliation: Department of Biochemistry and Molecular Biology, Nanjing Medical University, Nanjing, Jiangsu, People's Republic of China.
authors.forename: Jinsong
authors.initials: J
authors.lastname: Yang
authors.forename: Ming
authors.initials: M
authors.lastname: Sun
authors.forename: Aiping
authors.initials: A
authors.lastname: Zhang
authors.forename: Chengyu
authors.initials: C
authors.lastname: Lv
authors.forename: Wei
authors.initials: W
authors.lastname: De
authors.forename: Zhaoxia
authors.initials: Z
authors.lastname: Wang
mesh_terms: D000256:Adenoviridae / Q000235:genetics*; D000818:Animals; D017209:Apoptosis; D015153:Blotting, Western; D045744:Cell Line, Tumor; D002465:Cell Movement; D049109:Cell Proliferation; D003114:Colony-Forming Units Assay; D015179:Colorectal Neoplasms / Q000378:metabolism / Q000473:pathology / Q000517:prevention & control*; D004797:Enzyme-Linked Immunosorbent Assay; D005260:Female; D005434:Flow Cytometry; D006801:Humans; D007124:Immunoenzyme Techniques; D051379:Mice; D008807:Mice, Inbred BALB C; D008819:Mice, Nude; D012333:RNA, Messenger; D034741:RNA, Small Interfering / Q000235:genetics*; D011836:Radiation Tolerance; D020133:Reverse Transcriptase Polymerase Chain Reaction; D014945:Wound Healing; D051020:bcl-X Protein / Q000037:antagonists & inhibitors / Q000235:genetics / Q000378:metabolism*
chemical_list: D012333:RNA, Messenger; D034741:RNA, Small Interfering; D051020:bcl-X Protein