Expression and clinical significance of multidrug resistance protein in the blood-brain barrier of tumors

Objective To investigate the mechanism of the multidrug resistance in intracranial tumors. Methods Immunohistochemistry was used to detect the expression and location of P-glycoprotein (P-gp), muhidrug resistance-associated protein (MRP), Lung resistance-related protein (LRP), Topoisomerase Ⅱ (TopolI) and Glutathione-S-transferase-π(GST-π) in 30 patients; tumor tissues and 5 normal brain tissues. Results The high expression of P-gp was detected in vessel walls and the tissue around vessels. However, the expression of pogp was low in tumor cells. The expression of the other 4 multidrug resistance proteins couldn't be observed in vessel walls. Conclusions The chemotherapeutics drugs were interrupted in the end-feet of neuroepithelial cells of the bloodbrain barrier by P-gp, which weakened the chemotherapeutic effect. Key words: Muhidrug resistance-associated proteins;  Blood-brain barrier;  Neoplasms