Platycodin D inhibits migration, invasion, and growth of MDA-MB-231 human breast cancer cells via suppression of EGFR-mediated Akt and MAPK pathways

Chem Biol Interact. 2013 Oct 5;205(3):212-21. doi: 10.1016/j.cbi.2013.07.002. Epub 2013 Jul 16.

Abstract

Platycodin D (PD), an active triterpenoid saponin from Platycodon grandiflorum, has been known to inhibit the proliferation of a variety of cancer cells, but the effect of PD on the invasiveness of cancer cells is largely unknown. In this study, we first determined the molecular mechanism by which PD inhibits the migratory and invasive abilities of the highly metastatic MDA-MB-231 breast cancer cell line. We demonstrated that a non-cytotoxic concentration of PD markedly suppressed wound healing migration, invasion through the matrigel, and adhesion to an ECM-coated substrate in a dose-dependent manner. Moreover, PD inhibited cell invasion by reducing matrix metalloproteinase (MMP)-9 enzyme activity and mRNA expression. Western blot analysis indicated that PD potently suppressed the phosphorylation of extracellular signal-regulated kinase (ERK), p38, and c-Jun N-terminal kinase (JNK) as well as blocked the phosphatidylinositol-3-kinase (PI3K)/Akt/mTOR signaling pathway. Furthermore, PD treatment inhibited the DNA binding activity of NF-κB, which is known to mediate the expression of epidermal growth factor receptor (EGFR), as observed by electrophoretic mobility shift assay. Specific mechanisms of action exerted by PD involved the downregulation of EGFR and the inhibition of EGF-induced activation of the EGFR, MAPK, and PI3K/Akt pathways. The in vivo studies showed that PD significantly inhibited the growth of MDA-MB-231 xenograft tumors in BALB/c nude mice. These results suggest that PD might be a potential therapeutic candidate for the treatment of breast cancer metastasis.

Keywords: 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide; Akt; DMEM; DPBS; Dulbecco’s modified Eagle’s medium; Dulbecco’s phosphate buffered saline; ECM; EGFR; ER; ERK; Invasion; JNK; MAPK; MMP; MMP-9; MTT; PD; PI3K; Platycodin D; c-Jun N-terminal kinase; epidermal growth factor receptor; estrogen receptor; extracellular matrix; extracellular signal-regulated kinase; matrix metalloproteinase; mitogen-activated protein kinase; phosphatidylinositol-3-kinase; platycodin D.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Breast Neoplasms / drug therapy*
  • Breast Neoplasms / enzymology
  • Breast Neoplasms / genetics
  • Breast Neoplasms / pathology*
  • Cell Line, Tumor
  • Cell Movement / drug effects*
  • ErbB Receptors / metabolism*
  • Female
  • Humans
  • Immunohistochemistry
  • MAP Kinase Signaling System / drug effects*
  • Matrix Metalloproteinase 9 / genetics
  • Matrix Metalloproteinase 9 / metabolism
  • Mice
  • Mice, Inbred BALB C
  • Mice, Nude
  • Mitogen-Activated Protein Kinases / antagonists & inhibitors
  • Mitogen-Activated Protein Kinases / metabolism*
  • NF-kappa B / metabolism
  • RNA, Neoplasm / chemistry
  • RNA, Neoplasm / genetics
  • Random Allocation
  • Real-Time Polymerase Chain Reaction
  • Saponins / pharmacology*
  • Triterpenes / pharmacology*
  • Xenograft Model Antitumor Assays

Substances

  • NF-kappa B
  • RNA, Neoplasm
  • Saponins
  • Triterpenes
  • platycodin D
  • ErbB Receptors
  • Mitogen-Activated Protein Kinases
  • Matrix Metalloproteinase 9