Horizontal Transfer of Tamoxifen Resistance in MCF-7 Cell Derivates: Proteome Study

ABSTRACT

Using estrogen-dependent MCF-7 breast cancer cells and tamoxifen-resistant MCF-7/T subline we have shown that their co-cultivation lead to increase in tamoxifen resistance in the parent MCF-7 cells. The proteome analysis of MCF-7/T cells and new-generated resistant cells revealed 21 common proteins differently expressed in both the resistant cell lines, among them - 6 proteins were associated with the drug or hormonal resistance. Both resistant lines were characterized with suppression of estrogen receptor and activation of SNAIL1-signaling - mesenchymal pathway playing an important role in the down-regulation of estrogen receptor and maintaining of the estrogen-independent phenotype.

KEYWORDS:

• breast cancer
• Signal transduction pathways
• Tamoxifen resistance
• Epithelial-mesenchymal transition
• SNAIL1

Conflict of interest

The authors declare no conflict of interest regarding this article.

Acknowledgments

We thank Dr. Irina Zhitnyak and Dr. Natalya Gloushankova (N.N.Blokhin Cancer Research Centre) for consulting and kindly help with immunohistochemical analysis and microscopy. Anti-NFκB antibodies were gift by Dr. Victor Tatarskii Jr. (N.N.Blokhin Cancer Research Centre). GFP-expressing plasmid was kindly provided by Dr. Dmitri Andreev (Belozersky Institute of Physico-Chemical Biology). We thank Dr. George Reid for providing ERE-Luc plasmid.

Financial support

This study was supported by Russian Science Foundation, grant 14–15–00362 M.K.