Co-Treatment with Sulforaphane and Nano-Metformin Molecules Accelerates Apoptosis in HER2+ Breast Cancer Cells by Inhibiting Key Molecules

Abstract

Breast cancer cell lines MCF-10, MCF-7 and BT-474 expressing various levels of HER2 were examined for their response to treatment with sulforaphane (SLFN), metformin (MTFN), Nano-MTFN or combinations. Direct correlation was found between SLFN effect on cell death and HER2 levels. Bioinformatic studies suggested the possibility of additive co-effects on cell fate by SLFN-MTFN co-treatment. This co-treatment specially with SLFN + Nano-MTFN significantly affected the survival of the cells and killed more BT-474 cells than the other two. Cell sensitivity to SLFN-MTFN combination correlated with HER2 expression levels. RT-PCR showed that parallel with cell death, expression of BCL-2, SRC, WNT1, β-catenin and CD44 are diminished, whereas BAX levels are elevated significantly. Cell co-staining indicated that apoptosis percent correlates with cell death following different treatments. We also found that cell death induced by SLFN-MTFN co-treatment is in direct correlation with HER2 levels and increased cell death correlates directly with BAX levels but inversely with levels of cancer stem cell (CSC) signaling genes and CD44. In conclusion, our data indicate that SLFN and MTFN can reduce cancer cell viability via both collaborative and differential effects and suggest that MTFN increases SLFN effectiveness by targeting common molecules/pathways downstream of HER2 and key for CSC signaling.

Acknowledgment

This study was financially supported by a grant from National Institute of Genetic Engineering and Biotechnology (NIGEB) (Grant 502). We thank colleagues in NIGEB for their technical assistance and scientific advice.

Disclosure Statement

The authors declare no conflict of interest.

Additional information

Notes on contributors

A. Keshandehghan

MG planned the whole project to which he received grant, conceived and designed study experiments, and drafted the whole manuscript; AK carried out the cell molecular biology section of the experiments. HT designed the nano section of the study and supervised others to do nano experiments and interpreted data. SN and SHK conducted nano experiments and analyzed data. SHK further analyzed viability of cancer cells treated with nano particles. All authors contributed to paper writing with MG and HT frequently editing the manuscript. The authors have read and approved the final manuscript.

S. Nikkhah

MG planned the whole project to which he received grant, conceived and designed study experiments, and drafted the whole manuscript; AK carried out the cell molecular biology section of the experiments. HT designed the nano section of the study and supervised others to do nano experiments and interpreted data. SN and SHK conducted nano experiments and analyzed data. SHK further analyzed viability of cancer cells treated with nano particles. All authors contributed to paper writing with MG and HT frequently editing the manuscript. The authors have read and approved the final manuscript.

H. Tahermansouri

MG planned the whole project to which he received grant, conceived and designed study experiments, and drafted the whole manuscript; AK carried out the cell molecular biology section of the experiments. HT designed the nano section of the study and supervised others to do nano experiments and interpreted data. SN and SHK conducted nano experiments and analyzed data. SHK further analyzed viability of cancer cells treated with nano particles. All authors contributed to paper writing with MG and HT frequently editing the manuscript. The authors have read and approved the final manuscript.

S. Heidari-Keshel

MG planned the whole project to which he received grant, conceived and designed study experiments, and drafted the whole manuscript; AK carried out the cell molecular biology section of the experiments. HT designed the nano section of the study and supervised others to do nano experiments and interpreted data. SN and SHK conducted nano experiments and analyzed data. SHK further analyzed viability of cancer cells treated with nano particles. All authors contributed to paper writing with MG and HT frequently editing the manuscript. The authors have read and approved the final manuscript.

M. Gardaneh

MG planned the whole project to which he received grant, conceived and designed study experiments, and drafted the whole manuscript; AK carried out the cell molecular biology section of the experiments. HT designed the nano section of the study and supervised others to do nano experiments and interpreted data. SN and SHK conducted nano experiments and analyzed data. SHK further analyzed viability of cancer cells treated with nano particles. All authors contributed to paper writing with MG and HT frequently editing the manuscript. The authors have read and approved the final manuscript.