Targeting Mortalin by Embelin Causes Activation of Tumor Suppressor p53 and Deactivation of Metastatic Signaling in Human Breast Cancer Cells

PLoS One. 2015 Sep 16;10(9):e0138192. doi: 10.1371/journal.pone.0138192. eCollection 2015.

Abstract

Embelin, a natural quinone found in the fruits of Embelia ribes, is commonly used in Ayurvedic home medicine for a variety of therapeutic potentials including anti-inflammation, anti-fever, anti-bacteria and anti-cancer. Molecular mechanisms of these activities and cellular targets have not been clarified to-date. We demonstrate that the embelin inhibits mortalin-p53 interactions, and activates p53 protein in tumor cells. We provide bioinformatics, molecular docking and experimental evidence to the binding affinity of embelin with mortalin and p53. Binding of embelin with mortalin/p53 abrogates their complex resulted in nuclear translocation and transcriptional activation function of p53 causing growth arrest in cancer cells. Furthermore, analyses of growth factors and metastatic signaling using antibody membrane array revealed their downregulation in embelin-treated cells. We also found that the embelin causes transcriptional attenuation of mortalin and several other proteins involved in metastatic signaling in cancer cells. Based on these molecular dynamics and experimental data, it is concluded that the anticancer activity of embelin involves targeting of mortalin, activation of p53 and inactivation of metastatic signaling.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Apoptosis
  • Benzoquinones / pharmacology*
  • Blotting, Western
  • Breast Neoplasms / drug therapy*
  • Breast Neoplasms / metabolism
  • Breast Neoplasms / pathology
  • Cell Proliferation
  • Female
  • Gene Expression Regulation, Neoplastic / drug effects*
  • HSP70 Heat-Shock Proteins / genetics
  • HSP70 Heat-Shock Proteins / metabolism*
  • Humans
  • Neoplasm Metastasis
  • Primulaceae / chemistry*
  • Protein Array Analysis
  • RNA, Messenger / genetics
  • Real-Time Polymerase Chain Reaction
  • Reverse Transcriptase Polymerase Chain Reaction
  • Signal Transduction / drug effects*
  • Tumor Cells, Cultured
  • Tumor Suppressor Protein p53 / genetics
  • Tumor Suppressor Protein p53 / metabolism*

Substances

  • Benzoquinones
  • HSP70 Heat-Shock Proteins
  • RNA, Messenger
  • TP53 protein, human
  • Tumor Suppressor Protein p53
  • mortalin
  • embelin

Grants and funding

The study was supported by National Institute of Advanced Industrial Science & Technology (AIST) Special Research Grant.