Inhibition of Hepatocellular Carcinoma by Total Alkaloids of Rubus alceifolius Poir Involves Suppression of Hedgehog Signaling.

Abstract

We evaluated the effects of total alkaloids of Rubus alceifolius Poir (TARAP) on the migration and invasion of hepatocellular carcinoma (HCC) and furthermore investigated the possible molecular mechanisms mediating its anticancer activity. We implanted nude mice with human HCC HepG2 cells and fed them with vehicle (physiological saline) or 3 g/kg/day dose of TARAP 5 days per week for 21 days. We determined the in vitro effect of TARAP on the migration and invasion of HepG2 cells by transwell assay. We evaluated SHH signaling components' (SHH, PTCH, SMO, and Gli1) expression levels by reverse transcriptase-polymerase chain reaction and immunohistochemistry. Activity of the matrix metalloproteinases (MMPs) in supernatants was analyzed by zymography. The expression of the MMPs and their specific tissue inhibitor (tissue inhibitor of matrix metalloproteinases, TIMP-1, 2) in HCC tissues was detected by immunohistochemistry. We discovered that TARAP inhibited hepatocellular migration and invasion in a dose-dependent manner in vitro. In addition, TARAP decreased the expression of SHH, PTCH, SMO, and Gli1 in HCC mouse tumors at both transcriptional and translational levels. Moreover, TARAP inhibited the activity of MMP2 and MMP9. We found that TARAP reduced the expression of MMP2 and MMP9, as well as the tissue inhibitor of MMPs. Our study showed that TARAP inhibits HCC migration and invasion likely through suppression of the hedgehog pathway. This may, in part, explain its anticancer properties. These results suggest that total alkaloids in Rubus alceifolius may have potential as a novel antimetastasis drug in the treatment of HCC.