Synergistic inhibition of characteristics of liver cancer stem-like cells with a combination of sorafenib and 8-bromo-7-methoxychrysin in SMMC-7721 cell line

Oncol Rep. 2016 Sep;36(3):1731-8. doi: 10.3892/or.2016.4973. Epub 2016 Jul 25.

Abstract

Sorafenib, a multi-kinase inhibitor, has shown its promising antitumor effect in a series of clinical trials, and has been approved as the current standard treatment for advanced hepatocellular carcinoma (HCC). 8-Bromo‑7-methoxychrysin (BrMC) is a novel chrysin synthetic analogue that has been reported to inhibit the growth of various tumor cells and possess properties for targeting liver cancer stem cells (LCSCs) . The present study investigated the synergistic targeting effects on the properties of liver cancer stem-like cells (LCSLCs) by a combination of sorafenib and BrMC in SMMC-7721 cell line. We also investigated whether this effect involves regulation of HIF-1α, Twist and NF-κB protein. We found that the sphere-forming cells (SFCs) from the SMMC‑7721 cells possessed the properties of LCSLCs. Sorafenib diminished the self-renewal capacity and downregulated the expression of stem cell biomarkers (CD133, CD44 and ALDH1) in a dose-dependent manner, while BrMC cooperated with sorafenib to strengthen this inhibition. Moreover, the combination of sorafenib and BrMC led to a remarkable decrease in the cellular migration and invasion, the downregulation of N-cadherin protein and upregulation of E-cadherin protein, and increase of cell apoptosis in LCSLCs. BrMC has a remarkable antagonistic effect on the upregulation of protein expression and DNA binding activity of NF-κB (p65) induced by sorafenib. In addition, our results indicated that the synergistic inhibition of sorafenib and BrMC on the characteristics of LCSLCs involves the downregulated expression of HIF-1α and EMT regulator Twist1. Collectively, the combination therapy of sorafenib and BrMC could be a new and promising therapeutic approach in the treatment of HCC.

MeSH terms

  • Antineoplastic Combined Chemotherapy Protocols / pharmacology*
  • Apoptosis / drug effects
  • Blotting, Western
  • Carcinoma, Hepatocellular / pathology
  • Cell Line, Tumor
  • Cell Movement / drug effects
  • Drug Synergism
  • Flavonoids / administration & dosage*
  • Flow Cytometry
  • Humans
  • Liver Neoplasms / pathology*
  • Neoplastic Stem Cells / drug effects*
  • Niacinamide / administration & dosage
  • Niacinamide / analogs & derivatives*
  • Phenylurea Compounds / administration & dosage*
  • Sorafenib

Substances

  • 8-bromo-7-methoxychrysin
  • Flavonoids
  • Phenylurea Compounds
  • Niacinamide
  • Sorafenib