title: Downregulation of CD44 reduces doxorubicin resistance of CD44CD24 breast cancer cells.
abstract: BACKGROUND
  Cells within breast cancer stem cell populations have been confirmed to have a CD44(+)CD24(-) phenotype. Strong expression of CD44 plays a critical role in numerous types of human cancers. CD44 is involved in cell differentiation, adhesion, and metastasis of cancer cells.
  
  
  METHODS
  In this study, we reduced CD44 expression in CD44(+)CD24(-) breast cancer stem cells and investigated their sensitivity to an antitumor drug. The CD44(+)CD24(-) breast cancer stem cells were isolated from breast tumors; CD44 expression was downregulated with siRNAs followed by treatment with different concentrations of the antitumor drug.
  
  
  RESULTS
  The proliferation of CD44 downregulated CD44(+)CD24(-) breast cancer stem cells was decreased after drug treatment. We noticed treated cells were more sensitive to doxorubicin, even at low doses, compared with the control groups.
  
  
  CONCLUSIONS
  It would appear that expression of CD44 is integral among the CD44(+)CD24(-) cell population. Reducing the expression level of CD44, combined with doxorubicin treatment, yields promising results for eradicating breast cancer stem cells in vitro. This study opens a new direction in treating breast cancer through gene therapy in conjunction with chemotherapy.
authors.affiliation: Laboratory of Stem Cell Research and Application, University of Science, Vietnam National University, Ho Chi Minh, Vietnam.
authors.forename: Pham
authors.initials: P
authors.lastname: Van Phuc
authors.forename: Phan Lu Chinh
authors.initials: PL
authors.lastname: Nhan
authors.forename: Truong Hai
authors.initials: TH
authors.lastname: Nhung
authors.forename: Nguyen Thanh
authors.initials: NT
authors.lastname: Tam
authors.forename: Nguyen Minh
authors.initials: NM
authors.lastname: Hoang
authors.forename: Vuong Gia
authors.initials: VG
authors.lastname: Tue
authors.forename: Duong Thanh
authors.initials: DT
authors.lastname: Thuy
authors.forename: Phan Kim
authors.initials: PK
authors.lastname: Ngoc