Oldenlandia diffusa extracts exert antiproliferative and apoptotic effects on human breast cancer cells through ERα/Sp1-mediated p53 activation

J Cell Physiol. 2012 Oct;227(10):3363-72. doi: 10.1002/jcp.24035.

Abstract

Breast cancer is the most frequent tumor and a major cause of death among women. Estrogens play a crucial role in breast tumor growth, which is the rationale for the use of hormonal antiestrogen therapies. Unfortunately, not all therapeutic modalities are efficacious and it is imperative to develop new effective antitumoral drugs. Oldenlandia diffusa (OD) is a well-known medicinal plant used to prevent and treat many disorders, especially cancers. The aim of this study was to investigate the effects of OD extracts on breast cancer cell proliferation. We observed that OD extracts strongly inhibited anchorage-dependent and -independent cell growth and induced apoptosis in estrogen receptor alpha (ERα)-positive breast cancer cells, whereas proliferation and apoptotic responses of MCF-10A normal breast epithelial cells were unaffected. Mechanistically, OD extracts enhance the tumor suppressor p53 expression as a result of an increased binding of ERα/Sp1 complex to the p53 promoter region. Finally, we isolated ursolic and oleanolic acids as the bioactive compounds able to upregulate p53 expression and inhibit breast cancer cell growth. These acids were greatly effective in reducing tamoxifen-resistant growth of a derivative MCF-7 breast cancer cell line resistant to the antiestrogen treatment. Our results evidence how OD, and its bioactive compounds, exert antiproliferative and apoptotic effects selectively in ERα-positive breast cancer cells, highlighting the potential use of these herbal extracts as breast cancer preventive and/or therapeutic agents.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Apoptosis / drug effects*
  • Breast Neoplasms / drug therapy*
  • Breast Neoplasms / genetics
  • Breast Neoplasms / metabolism
  • Cell Line, Tumor
  • Cell Proliferation / drug effects
  • Cyclin-Dependent Kinase Inhibitor p21 / genetics
  • Cyclin-Dependent Kinase Inhibitor p21 / metabolism
  • Drug Resistance, Neoplasm / drug effects
  • Drug Resistance, Neoplasm / genetics
  • Estrogen Receptor Modulators / pharmacology
  • Estrogen Receptor alpha / genetics*
  • Estrogen Receptor alpha / metabolism
  • Estrogens / metabolism
  • Female
  • Gene Expression Regulation, Neoplastic / drug effects
  • Humans
  • Immunoglobulins / genetics*
  • Immunoglobulins / metabolism
  • Oldenlandia / chemistry*
  • Oleanolic Acid / pharmacology
  • Plant Extracts / pharmacology*
  • Promoter Regions, Genetic / drug effects
  • Tamoxifen / pharmacology
  • Transcriptional Activation / drug effects
  • Transcriptional Activation / genetics
  • Triterpenes / pharmacology
  • Tumor Suppressor Protein p53 / genetics*
  • Tumor Suppressor Protein p53 / metabolism
  • Up-Regulation / drug effects

Substances

  • Cyclin-Dependent Kinase Inhibitor p21
  • ESR1 protein, human
  • Estrogen Receptor Modulators
  • Estrogen Receptor alpha
  • Estrogens
  • Immunoglobulins
  • Plant Extracts
  • SP1 antigen
  • TP53 protein, human
  • Triterpenes
  • Tumor Suppressor Protein p53
  • Tamoxifen
  • Oleanolic Acid
  • ursolic acid