Contribution of the ABC transporters Bcrp1 and Mdr1a/1b to the side population phenotype in mammary gland and bone marrow of mice

Stem Cells. 2005 Sep;23(8):1059-65. doi: 10.1634/stemcells.2005-0150. Epub 2005 Jul 7.

Abstract

The ability of cells to export Hoechst 33342 can be used to identify a subpopulation of cells (side population [SP]) with characteristics of stem cells in many tissues. The ATP-binding cassette transporters Bcrp1 (Abcg2) and Mdr1a/1b (Abcb1a/1b) have been implicated as being responsible for this phenotype. To further explore the involvement of these transporters in the SP phenotype, we have generated Bcrp1/Mdr1a/1b triple knockout mice and studied the effect of their absence on the SP in bone marrow and mammary gland. Whereas in bone marrow Bcrp1 was almost exclusively responsible for the SP, both transporters contributed to the SP phenotype in the mammary gland, where their combined absence resulted in a nearly complete loss of SP. Interestingly, bone marrow of Mdr1a/1b-/- mice frequently displayed an elevated SP, which was reversible by the Bcrp1 inhibitor Ko143, suggesting that Bcrp1 can compensate for the loss of Mdr1a/1b in bone marrow.

Publication types

  • Comparative Study
  • Research Support, Non-U.S. Gov't

MeSH terms

  • ATP Binding Cassette Transporter, Subfamily B / genetics
  • ATP Binding Cassette Transporter, Subfamily B / physiology*
  • ATP Binding Cassette Transporter, Subfamily G, Member 2
  • ATP-Binding Cassette Transporters / genetics
  • ATP-Binding Cassette Transporters / physiology*
  • Animals
  • Benzimidazoles
  • Bone Marrow Cells / cytology*
  • Bone Marrow Cells / metabolism
  • Cell Survival
  • Epithelial Cells / metabolism
  • Female
  • Flow Cytometry
  • Gene Silencing
  • Hematopoietic Stem Cells / metabolism
  • Immunohistochemistry
  • Mammary Glands, Animal / cytology*
  • Mammary Glands, Animal / metabolism
  • Mice
  • Mice, Knockout
  • Phenotype

Substances

  • ATP Binding Cassette Transporter, Subfamily B
  • ATP Binding Cassette Transporter, Subfamily G, Member 2
  • ATP-Binding Cassette Transporters
  • Abcg2 protein, mouse
  • Benzimidazoles
  • P-glycoprotein 2
  • multidrug resistance protein 3
  • bisbenzimide ethoxide trihydrochloride