Hinokitiol suppresses growth of B16 melanoma by activating ERK/MKP3/proteosome pathway to downregulate survivin expression

Toxicol Appl Pharmacol. 2019 Mar 1:366:35-45. doi: 10.1016/j.taap.2019.01.015. Epub 2019 Jan 23.

Abstract

Metastasis is the major cause of treatment failure in patients with cancer. Hinokitiol, a metal chelator derived from natural plants, has anti-inflammatory and antioxidant activities as well as anticancer effects. We investigated the potential anticancer effects of hinokitiol in metastatic melanoma cell line B16-F10. Exposure of the melanoma B16-F10 cells to hinokitiol significantly inhibited colony formation and cell viability in a time and concentration-dependent manner. The hinokitiol-treated cells exhibited apoptotic features in morphological assay. Results from Western blot and immunoprecipitation showed that hinokitiol treatment decreased survivin protein levels and increased suvivin ubiquitination. Pretreatment with proteosome inhibitors effectively prevented hinokitiol-induced decrease in survivin expression, implying that ubiquitin/proteosome pathway involved in hinokitiol-reduced survivin expression. Hinokitiol rapidly induced ERK phosphorylation followed by a sustained dephosphorylation, which accompanied with an increase in expression of tumor suppressor MKP-3 (mitogen-activated protein kinase phosphatase-3). Inhibition of hinokitiol-induced ERK activation by MEK inhibitor U0126 completely blocked expression of MKP-3. More importantly, inhibition of MKP-3 activity by NSC 95397 significantly inhibited hinokitiol-induced ERK dephosphorylation, ubiquitination and downregulation of survivin. These results suggested that hinokitiol inhibited growth of B16-F10 melanoma through downregulation of survivin by activating ERK/MKP-3/proteosome pathway. Hinokitiol-inhibition of survivin may be a novel and potential approach for melanoma therapy. Hinokitiol can be useful for developing therapeutic agent for melanoma.

Keywords: B16 melanoma; ERK; Hinokitiol; MAPK phosphatase-3; Proteosome; Survivin; Ubiquitin.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Antineoplastic Agents / pharmacology*
  • Apoptosis / drug effects
  • Cell Line, Tumor
  • Cell Proliferation / drug effects
  • Cell Survival / drug effects
  • Down-Regulation
  • Dual Specificity Phosphatase 6 / metabolism*
  • Enzyme Activation
  • Extracellular Signal-Regulated MAP Kinases / metabolism*
  • Melanoma, Experimental / drug therapy*
  • Melanoma, Experimental / enzymology
  • Melanoma, Experimental / pathology
  • Mice
  • Monoterpenes / pharmacology*
  • Phosphorylation
  • Proteasome Endopeptidase Complex / drug effects*
  • Proteasome Endopeptidase Complex / metabolism
  • Proteolysis
  • Signal Transduction / drug effects
  • Survivin / metabolism*
  • Tropolone / analogs & derivatives*
  • Tropolone / pharmacology
  • Ubiquitination

Substances

  • Antineoplastic Agents
  • Birc5 protein, mouse
  • Monoterpenes
  • Survivin
  • Tropolone
  • Extracellular Signal-Regulated MAP Kinases
  • Dual Specificity Phosphatase 6
  • Dusp6 protein, mouse
  • Proteasome Endopeptidase Complex
  • beta-thujaplicin