Dietary chemopreventative benzyl isothiocyanate inhibits breast cancer stem cells in vitro and in vivo

Cancer Prev Res (Phila). 2013 Aug;6(8):782-90. doi: 10.1158/1940-6207.CAPR-13-0100. Epub 2013 May 9.


A small subset of mammary tumor-initiating cells (also known as breast cancer stem cells; bCSC), characterized by expression of different markers [CD44(high)/CD24(low)/epithelial-specific antigen (ESA)+], aldehyde dehydrogenase-1 (ALDH1) activity, and ability to form mammospheres under ultra-low attachment culture conditions, are suspected to evade conventional therapies leading to disease recurrence. Elimination of both therapy-sensitive epithelial tumor cells and therapy-resistant bCSC is therefore necessary for prevention of breast cancer. We have shown previously that a nontoxic small-molecule constituent of edible cruciferous vegetables (benzyl isothiocyanate; BITC) inhibits mammary cancer development in mouse mammary tumor virus-neu (MMTV-neu) transgenic mice by causing epithelial tumor cell apoptosis. The present study shows efficacy of BITC against bCSC in vitro and in vivo. Mammosphere formation frequency and CD44(high)/CD24(low)/ESA+ and/or ALDH1+ populations in cultured MCF-7 (estrogen receptor-positive) and SUM159 (triple-negative) human breast cancer cells were decreased significantly in the presence of plasma achievable concentrations of BITC. BITC administration in the diet (3 μmol BITC/g diet for 29 weeks) resulted in a marked decrease in bCSCs in the MMTV-neu mice tumors in vivo. Overexpression of full-length Ron as well as its truncated form (sfRon), but not urokinase-type plasminogen activator receptor, conferred near complete protection against BITC-mediated inhibition of bCSCs in MCF-7 cells. The BITC treatment downregulated protein levels of Ron and sfRon in cultured breast cancer cells and in tumor xenografts. Ron overexpression resulted in upregulation of bCSC-associated genes Oct-4, SOX-2, and Nanog. In conclusion, the present study indicates that BITC treatment eliminates bCSCs in vitro and in vivo.

Publication types

  • Research Support, N.I.H., Extramural

MeSH terms

  • Animals
  • Apoptosis*
  • Blotting, Western
  • Breast Neoplasms / metabolism
  • Breast Neoplasms / pathology
  • Breast Neoplasms / prevention & control*
  • Cell Proliferation
  • Diet*
  • Epithelial-Mesenchymal Transition*
  • Female
  • Flow Cytometry
  • Humans
  • In Vitro Techniques
  • Isothiocyanates / pharmacology*
  • Mammary Tumor Virus, Mouse / genetics
  • Mice
  • Mice, Transgenic
  • Neoplastic Stem Cells / drug effects*
  • Neoplastic Stem Cells / metabolism
  • Neoplastic Stem Cells / pathology
  • RNA, Messenger / genetics
  • Real-Time Polymerase Chain Reaction
  • Reverse Transcriptase Polymerase Chain Reaction
  • Tumor Cells, Cultured


  • Isothiocyanates
  • RNA, Messenger
  • benzyl isothiocyanate