L-Tetrahydropalmatine Inhibits the Progression of Glioblastoma Tumor by Suppressing the Extracellular-Signal-Regulated Kinase/Nuclear Factor-Kappa B Signaling Pathway

Abstract

Glioblastoma multiforme is the most common malignancy of central nervous system. Herein we have evaluated the effect of L-tetrahydropalmatine, an isoquinoline alkaloid, on the tumor growth both in vivo and in vitro using C6 glioblastoma multiforme cells and BALB/c mice injected subcutaneously with C6/luc2 cells. The results of these studies show that L-tetrahydropalmatine exhibited cytotoxic effect on C6 glioblastoma multiforme cells, suppressed nuclear factor-kappa B activity, suppressed the levels of tumor-linked proteins such as matrix metalloproteinase-2/9, Cyclin-D1, vascular endothelial growth factor, and X-linked inhibitor of apoptosis protein via ERK/nuclear factor-kappa B cascade. Further, L-tetrahydropalmatine inhibited the cell migration and invasion properties of C6 cells, and also suppressed the tumor weight and volume in mice. Immunohistochemical staining of tumor tissues suggested that L-tetrahydropalmatine inhibited the extracellular-signal-regulated kinase/nuclear factor-kappa B cascade and suppressed the levels of Cyclin-D1; matrix metalloproteinase-2/9; X-linked inhibitor of apoptosis protein; and vascular endothelial growth factor, and also the progression and growth of glioblastoma multiforme in mice. In summary, L-tetrahydropalmatine inhibits the ERK/nuclear factor-kappa B cascade, decreases the tumor volume, and inhibits the proteins responsible for tumor growth both in vivo and in vitro.