Open AccessP‐Glycoprotein and Multidrug Resistance‐associated Protein Mediate Specific Patterns of Multidrug Resistance in Malignant Glioma Cell Lines, but not in Primary Glioma Cells
Author(s) -
Bähr Oliver,
Rieger Johannes,
Duffner Frank,
Meyermann Richard,
Weller Michael,
Wick Wolfgang
Publication year - 2003
Publication title -
brain pathology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.986
H-Index - 132
eISSN - 1750-3639
pISSN - 1015-6305
DOI - 10.1111/j.1750-3639.2003.tb00479.x
Subject(s) - teniposide , glioma , multiple drug resistance , cancer research , p glycoprotein , in vivo , doxorubicin , cytotoxic t cell , biology , cell culture , vincristine , pharmacology , drug resistance , in vitro , chemotherapy , etoposide , biochemistry , genetics , microbiology and biotechnology , cyclophosphamide
Understanding and overcoming multidrug resistance (MDR) may be a promising strategy to develop more effective pharmacotherapies for malignant gliomas. In the present study, human malignant glioma cell lines (n = 12) exhibited heterogeneous mRNAand protein expression and functional activity of the mdr gene‐encoded P‐glycoprotein (PGP) and MDR‐associated protein (MRP). Correlation between mRNA expression, protein levels and functional activity was strong. Inhibition of PGP activity by verapamil or PSC 833 enhanced the cytotoxic effects of vincristine, doxorubicin, teniposide and taxol. Inhibition of MRP activity by indomethacin or probenecid enhanced the cytotoxic effects of vincristine, doxorubicin and teniposide. The human cerebral endothelial cell line, SV‐HCEC, exhibited the strongest PGP activity of all cell lines. Five primary human glioblastomas and one anaplastic astrocytoma displayed heterogenous protein levels of PGP and MRP‐1 in tumor cells and of PGP in biopsy specimens in vivo, but no functional activity of these proteins upon ex vivo culturing. These data suggest that the glioma cell line‐associated MDR‐type drug resistance is a result of long‐term culturing and that cerebral endothelial, but not glioma cells, may contribute to MDR‐type drug resistance of gliomas in vivo.