title: The Effect of Sex on the Azoxymethane/Dextran Sulfate Sodium-treated Mice Model of Colon Cancer.
abstract: BACKGROUND
  The colitis-associated cancer exhibits different characteristics according to sex in the initiation and progression of the tumors. The aim of this study was to investigate the sex-associated difference in the azoxymethane/dextran sulfate sodium (AOM/DSS)-induced colitis-associated cancer model.
  
  
  METHODS
  The AOM/DSS ICR mouse model was established to compare male with female, and then the severity of colitis-associated carcinogenesis was examined macroscopically and histologically regarding the number, size, and location of tumors. Subsequently, levels of colonic mucosal cytokine, interleukin (IL)-1β and myeloperoxidase (MPO) were assessed.
  
  
  RESULTS
  At the 16th week, the tumor multiplicity and the pro-inflammatory factors differed according to sex. The total tumor number was significantly higher in male (P= 0.020) and the number of large tumors (diameter > 2 mm) was higher in male (P= 0.026). In male, the tumors located more in distal colon (P= 0.001). MPO was significantly higher in AOM/DSS-treated male mice compared to the control group (P= 0.003), whereas the corresponding female group showed no significant change (P= 0.086). Colonic IL-1β level significantly increased in AOM/DSS groups compared to control groups both in male and female (male,P= 0.014; female,P= 0.005). It was higher in male group; however, there was no statistical significance (P= 0.226).
  
  
  CONCLUSIONS
  In AOM/DSS murine model, colitis-associated colon tumorigenesis are induced more severely in male mice than female probably by way of inflammatory mediators such as IL-1β and MPO. The sex-related differences at the animal model of colon cancer suggest the importance of approach to disease with sex-specific medicine in human.
authors.affiliation: Department of Internal Medicine, Seoul National University Bundang Hospital, Seongnam, Korea.
authors.forename: Sun Min
authors.initials: SM
authors.lastname: Lee
authors.affiliation: Department of Internal Medicine, Seoul National University Bundang Hospital, Seongnam, Korea; Department of Internal Medicine and Liver Research Institute, Seoul National University College of Medicine, Seoul, Korea.
authors.forename: Nayoung
authors.initials: N
authors.lastname: Kim
authors.affiliation: Seoul National University College of Medicine, Seoul, Korea.
authors.forename: Hee Jin
authors.initials: HJ
authors.lastname: Son
authors.affiliation: Department of Internal Medicine and Liver Research Institute, Seoul National University College of Medicine, Seoul, Korea.
authors.forename: Ji Hyun
authors.initials: JH
authors.lastname: Park
authors.affiliation: Department of Internal Medicine, Seoul National University Bundang Hospital, Seongnam, Korea.
authors.forename: Ryoung Hee
authors.initials: RH
authors.lastname: Nam
authors.affiliation: Department of Internal Medicine, Seoul National University Bundang Hospital, Seongnam, Korea.
authors.forename: Min Hee
authors.initials: MH
authors.lastname: Ham
authors.affiliation: Department of Internal Medicine, Seoul National University Bundang Hospital, Seongnam, Korea.
authors.forename: Daeun
authors.initials: D
authors.lastname: Choi
authors.affiliation: Department of Internal Medicine, Seoul National University Bundang Hospital, Seongnam, Korea.
authors.forename: Sung Hwa
authors.initials: SH
authors.lastname: Sohn
authors.affiliation: Department of Pathology, Seoul National University Bundang Hospital, Seongnam, Korea.
authors.forename: Eun
authors.initials: E
authors.lastname: Shin
authors.affiliation: Department of Internal Medicine, Seoul National University Bundang Hospital, Seongnam, Korea.
authors.forename: Young-Jae
authors.initials: YJ
authors.lastname: Hwang
authors.affiliation: Department of Internal Medicine, Seoul National University Bundang Hospital, Seongnam, Korea.
authors.forename: Jihee
authors.initials: J
authors.lastname: Sung
authors.affiliation: Department of Internal Medicine, Seoul National University Bundang Hospital, Seongnam, Korea.
authors.forename: Dong Ho
authors.initials: DH
authors.lastname: Lee
authors.affiliation: Receptor Cell Biology Section, Laboratory of Immunogenetics, National Institute of Allergy and Infectious Diseases, NIH, Rockville, MD 20852, USA.
authors.forename: Ha-Na
authors.initials: HN
authors.lastname: Lee
keywords: Colitis; Colonic neoplasms; Disease models; Sex; animal