title: [Effect of CD133(+) cells on the radiosensitivity of rectal cancer cells].
abstract: OBJECTIVE
  To investigate the effect of CD133(+) cells on radiosensitivity of rectal cancer cells.
  
  
  METHODS
  In vitro experiments: CD133(+) cells were purified with Immunomagnetic beads from human rectal cancer cell line SW480 cells and annexin V/PI staining was used to determine apoptosis in CD133(+) and CD133(-) cells. In vivo experiments: Transplanted rectal tumor was established in 30 nude mice using primarily established SW480 cells. The tumor cells were divided into CD133-high and CD133-low groups based on the immunohistochemical staining of CD133 expression of the tumor cells. The tumor size after irradiation was recorded every three days.
  
  
  RESULTS
  CD133(+) cells had a much lower percentage of apoptosis after radiation exposure compared with CD133(-) cells [(12.6 ± 3.2) % vs. (38.8 ± 6.7) %, P < 0.01]. In vivo experiment showed that the normalized tumor size of CD133-high group (3.00 ± 0.32) became significantly larger than that of the CD133-low group(2.55 ± 0.29) at the ninth day and this difference lasted until the observation end (P < 0.05).
  
  
  CONCLUSIONS
  CD133(+) cells have a radioresistant effect on rectal cancer cells and may become a potential therapeutic target in the radiotherapy of rectal cancer.
authors.affiliation: Department of Coloproctology, the Third People's Hospital of Hangzhou, Hangzhou 310009, China.
authors.forename: Jianming
authors.initials: J
authors.lastname: Qiu
authors.affiliation: Department of Coloproctology, the Third People's Hospital of Hangzhou, Hangzhou 310009, China. Email: yangguangen88@126.com.
authors.forename: Guangen
authors.initials: G
authors.lastname: Yang
authors.affiliation: Department of Coloproctology, the Third People's Hospital of Hangzhou, Hangzhou 310009, China.
authors.forename: Zhong
authors.initials: Z
authors.lastname: Shen
authors.affiliation: Department of Coloproctology, the Third People's Hospital of Hangzhou, Hangzhou 310009, China.
authors.forename: Lei
authors.initials: L
authors.lastname: Ding
authors.affiliation: Department of Coloproctology, the Third People's Hospital of Hangzhou, Hangzhou 310009, China.
authors.forename: Dong
authors.initials: D
authors.lastname: Wang
authors.affiliation: Department of Coloproctology, the Third People's Hospital of Hangzhou, Hangzhou 310009, China.
authors.forename: Chen
authors.initials: C
authors.lastname: Wang
mesh_terms: D000071916:AC133 Antigen; D000230:Adenocarcinoma / Q000378:metabolism / Q000473:pathology* / Q000532:radiotherapy; D000368:Aged; D000818:Animals; D015703:Antigens, CD / Q000378:metabolism*; D017209:Apoptosis / Q000528:radiation effects*; D045744:Cell Line, Tumor; D006023:Glycoproteins / Q000378:metabolism*; D006801:Humans; D008297:Male; D051379:Mice; D008807:Mice, Inbred BALB C; D008819:Mice, Nude; D008875:Middle Aged; D009368:Neoplasm Transplantation; D010455:Peptides / Q000378:metabolism*; D011836:Radiation Tolerance; D011897:Random Allocation; D012004:Rectal Neoplasms / Q000378:metabolism / Q000473:pathology* / Q000532:radiotherapy; D047368:Tumor Burden / Q000528:radiation effects*
chemical_list: D000071916:AC133 Antigen; D015703:Antigens, CD; D006023:Glycoproteins; C000606023:PROM1 protein, human; D010455:Peptides; C000606024:Prom1 protein, mouse