Function of P-glycoprotein expressed in placenta and mole

Biochem Biophys Res Commun. 1997 Jun 27;235(3):849-53. doi: 10.1006/bbrc.1997.6855.


We examined the expression of P-glycoprotein in human placentas and hydatidiform moles. Trophoblasts in all the examined placentas and moles expressed P-glycoprotein, and the size of the P-glycoprotein was smaller than that in multidrug-resistant human epidermoid carcinoma KB cells. The P-glycoprotein in the placenta and mole was photolabeled with [3H]azidopine, and [3H]vincristine was transported in an ATP-dependent manner into membrane vesicles prepared from trophoblasts that expressed P-glycoprotein. These findings indicate that P-glycoprotein expressed in trophoblasts has a drug binding site(s) and the ability to transport vincristine, suggesting that P-glycoprotein in the placenta protects the fetus from xenobiotics and confers drug resistance on moles.

MeSH terms

  • ATP Binding Cassette Transporter, Subfamily B, Member 1 / analysis
  • ATP Binding Cassette Transporter, Subfamily B, Member 1 / biosynthesis*
  • Adenosine Triphosphate / metabolism
  • Azides / metabolism
  • Biological Transport
  • Dihydropyridines / metabolism
  • Drug Resistance, Multiple
  • Female
  • Humans
  • Hydatidiform Mole / metabolism*
  • Immunohistochemistry
  • KB Cells
  • Placenta / metabolism*
  • Pregnancy
  • Uterine Neoplasms / metabolism*
  • Vincristine / metabolism


  • ATP Binding Cassette Transporter, Subfamily B, Member 1
  • Azides
  • Dihydropyridines
  • Vincristine
  • azidopine
  • Adenosine Triphosphate