title: Culturing in serum-free culture medium on collagen type-I-coated plate increases expression of CD133 and retains original phenotype of HT-29 cancer stem cell.
abstract: BACKGROUND
  A sub-population of tumor cells termed cancer stem cells (CSCs) has an important role in tumor initiation, progression, and recurrence. Selecting a suitable procedure for isolation and enrichment of CSCs is the biggest challenge in the study of CSCs. In the present study, the role of the combination of stem cell culture medium and collagen type-I was evaluated for successful isolation and enrichment of HT-29 CSCs.
  
  
  METHODS
  HT-29 cells were cultured in serum-containing medium (parental culture medium: Medium + 10% fetal bovine serum) and serum-free medium (stem cell culture medium); both on collagen-coated plates. Spheres forming ability and CD133 expression, as a potential marker of colorectal CSCs, were evaluated in two culture mediums.
  
  
  RESULTS
  The results show spheroids usually give rise completely within 15 days in the stem cell culture medium on the collagen-coated plate. CD133 expression in spheroid cells (84%) is extensively higher than in parental cells (25%). Moreover, relative to parental cells, spheroid cells were more radioresistance.
  
  
  CONCLUSIONS
  Finding of this study suggested that CSCs derived from colon cancer cell line (HT-29) can be propagated and form colonospheres in serum-free culture medium on collagen type-I. According to maintenance of their original phenotype in these conditions, it seems serum-free culture medium on collagen type-I is a suitable way to drug screening of HT-29 CSCs.
authors.affiliation: Department of Medical Physics, Ahvaz Jundishapur University of Medical Sciences, Ahvaz, Iran.
authors.forename: Zahra
authors.initials: Z
authors.lastname: Arab-Bafrani
authors.affiliation: Department of Medical Physics, School of Medicine, Isfahan University of Medical Sciences, Isfahan, Iran.
authors.forename: Daryoush
authors.initials: D
authors.lastname: Shahbazi-Gahrouei
authors.affiliation: Department of Biotechnology, College of Agriculture, Isfahan University of Technology, Isfahan, Iran.
authors.forename: Mehdi
authors.initials: M
authors.lastname: Abbasian
authors.affiliation: Department of Medical Genetics, School of Medicine, Ahvaz Jundishapur University of Medical Sciences, Ahvaz, Iran.
authors.forename: Alihossein
authors.initials: A
authors.lastname: Saberi
authors.affiliation: Department of Cell Sciences, Research Center Medical Science, School of Medicine, Isfahan University of Medical Sciences, Isfahan, Iran.
authors.forename: Mehrafarin
authors.initials: M
authors.lastname: Fesharaki
authors.affiliation: Department of Parasitology and Mycology, School of Medicine, Isfahan University of Medical Sciences, Isfahan, Iran.
authors.forename: Seyed Hossein
authors.initials: SH
authors.lastname: Hejazi
authors.affiliation: Department of Pharmacology and Biotechnology, School of Biosciences, Sheffield Hallam University, Sheffield, UK.
authors.forename: Samira
authors.initials: S
authors.lastname: Manshaee
keywords: CD133 expression; Cancer stem cell; collagen type-I; spheroid