Breast cancer resistance
protein (BCRP)

ATP-binding cassette transporter, placenta-specific (ABCP)(Allikmets R. et al., 1998).

Gene: ABCP maps to 4q22
mRNA: 2.4 kb.
Protein: a 663-amino acid member of the ATP-binding cassette (ABC) superfamily of transporters. Highly expressed in placenta (Allikmets R. et al., 1998).

Cell lines:
- BCRP cDNA was cloned from a MCF-7 subline (MCF-7/AdrVp) resisting to doxorubicin (Adriamycin) in presence of the MDR1 inhibitor verapamil. Enforced expression of the full-length BCRP cDNA in MCF-7 breast cancer cells confers resistance to mitoxantrone, doxorubicin, and daunorubicin, reduces daunorubicin accumulation and retention, and causes an ATP-dependent enhancement of the efflux or rhodamine 123 in the cloned transfected cells. Thus, BCRP is a xenobiotic transporter that appears to play a major role in the multidrug resistance phenotype of a specific human breast cancer (Doyle L.A. et al., 1998).

- Analysis of genomic DNA from BCRP-overexpressing MCF-7/MX cells demonstrated that the BCRP gene was amplified in these cells (Ross D.D. et al., 1999).

Tumors:

Allikmets R. et al. (1998) A human placenta-specific ATP-binding cassette gene (ABCP) on chromosome 4q22 that is involved in multidrug resistance. Cancer Res. 58, 5337-5339.
Chauffert B. et al., (1999) Actualités sur les mécanismes de la chimiorésistance. Bull. Cancer 86, 97-103.
Doyle L.A. et al. (1998) A multidrug resistance transporter from human MCF-7 breast cancer cells. Proc. Nat. Acad. Sci. 95, 15665-15670.
Ross D.D. et al. (1999) Atypical multidrug resistance: breast cancer resistance protein messenger RNA expression in mitoxantrone-selected cell lines. J. Natl. Cancer Inst. 91, 429-433.

P-glycoprotein (P-gp) or MDR1, multidrug resistance related protein-1 (MRP-1)