Objective: To study the expression of P-glycoprotein, multi-drug resistance associated protein and major vault protein in pathologic brain specimens, and to investigate their roles in the pathogenesis of refractory epilepsy.
Methods: Immunohistochemical study was performed in pathology specimens from 18 cases of refractory epilepsy (including 5 cases of focal cortical dysplasia, 3 cases of tuberous sclerosis, 5 cases of ganglioglioma and 5 cases of dysembryoplastic neuroepithelial tumor).
Results: Both the P-glycoprotein and major vault protein were localized in microvascular endothelium of the lesions. Major vault protein was also seen in balloon cells and some neuronal cells. On the other hand, multi-drug resistance associated protein was mainly localized in the neuronal component of the lesions. In general, the expression of P-glycoprotein and major vault protein in tumoral tissue was higher than that in non-tumoral tissue. The expression of multi-drug resistance associated protein and major vault protein was also different in the neoplastic glial cells of ganglioglioma and dysembryoplastic neuroepithelial tumor.
Conclusions: P-glycoprotein, multi-drug resistance associated protein and major vault protein contribute to the pathogenesis of refractory epilepsy. They may however have different roles, with different cellular localization.