Evaluation of wild yam (Dioscorea villosa) root extract as a potential epigenetic agent in breast cancer cells

In Vitro Cell Dev Biol Anim. 2015 Jan;51(1):59-71. doi: 10.1007/s11626-014-9807-5. Epub 2014 Aug 23.


The present study was designed to evaluate the efficacy of wild yam root extract (WYRE) as a potential demethylating agent using two breast cancer cell lines, MCF-7 (estrogen receptor positive; ER(+)) and MDA-MB-231 (Estrogen receptor negative; ER(-)), and a methylated gene, GATA3, as a potential marker of breast cancer development. The cells were treated with WYRE (0-50 μg/mL) for 72 h and used for viability, mRNA, and methylation analyses. WYRE significantly reduced viability of both cell lines and enhanced mRNA content of GATA3 in a concentration-dependent manner; however, DNMT mRNAs (DNMT1, 3A, 3B) were found to increase significantly only in MDA-MB-231 cells. Global DNA methylation, analyzed as 5'-methyl-2'-deoxycytidine (5-mC) and 5-hydroxymethylcytosine (5-hmC), showed a concentration-dependent enhancement of 5-mC with no alteration in 5-hmC level in MCF-7 cells; however, in MDA-MB-231 cells, in contrast to MCF-7 cells, 5-mC remained unaltered but 5-hmC reduced significantly in all WYRE concentrations (10-50 μg/mL) used in this study. Since 5-hmC is generated from 5-mC by ten-eleven-translocation (TET) enzymes, analysis of TET mRNAs (TET1, TET2, and TET3) in MDA-MB-231 cells indicated a concentration-dependent reduction in TET1 and induction of TET3; however, TET2 remained unaltered. No alterations in any of the TET mRNAs were found in MCF-7 cells. Methylation analysis of GATA3 promoter at specific locus indicates probable demethylating activity of WYRE in MDA-MB-231 cells. We conclude that activation of GATA3 gene in ER(-) MDA-MB-231 cells may occur by altering DNA methylation pattern on the promoter region which may be different from the mechanisms operated in ER(+) MCF-7 cells.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, U.S. Gov't, Non-P.H.S.

MeSH terms

  • Breast Neoplasms / genetics*
  • Cell Line, Tumor
  • Cell Survival / drug effects
  • Cell Survival / genetics
  • DNA (Cytosine-5-)-Methyltransferases / genetics
  • DNA (Cytosine-5-)-Methyltransferases / metabolism
  • DNA Methylation / drug effects
  • DNA Methylation / genetics
  • Dioscorea / chemistry*
  • Epigenesis, Genetic / drug effects*
  • Female
  • GATA3 Transcription Factor / genetics
  • GATA3 Transcription Factor / metabolism
  • Gene Expression Regulation, Neoplastic / drug effects
  • Genetic Loci
  • Humans
  • Neoplasm Proteins / genetics
  • Neoplasm Proteins / metabolism
  • Plant Extracts / pharmacology*
  • Plant Roots / chemistry*
  • Promoter Regions, Genetic
  • RNA, Messenger / genetics
  • RNA, Messenger / metabolism


  • GATA3 Transcription Factor
  • GATA3 protein, human
  • Neoplasm Proteins
  • Plant Extracts
  • RNA, Messenger
  • DNA (Cytosine-5-)-Methyltransferases