Biopolym. Cell. 2025; 41(3):181.
http://dx.doi.org/10.7124/bc.000B1C
Structure and Function of Biopolymers
ESR1 gene editing and its impact on S6K1 signaling and cell behavior
1Savinska L. O., 1, 2Kvitchenko S. A., 1Kroupskaya I. V., 1Martsynyuk M. Ye., 1Pogrebna A. P., 1Mazov A. V., 1Garifulin O. M., 1Filonenko V. V.
  1. Institute of Molecular Biology and Genetics, NAS of Ukraine
    150, Akademika Zabolotnoho Str., Kyiv, Ukraine, 03143
  2. Educational and Scientific Center “Institute of Biology and Medicine” of Taras Shevchenko National University of Kyiv
    2, Akademika Hlushkova Ave., Kyiv, Ukraine, 03022

Abstract

Aim. The aim of this study was to validate the link between the expression of estrogen receptor alpha (ESR1) isoforms and the regulation of S6K1-dependent signaling using the previously generated MCF-7 sublines with the CRISPR/Cas9 editing of the ESR1 gene. Methods. Western blotting, RT-PCR analysis, resazurine cell proliferation assay, and wound healing assay. Results. The presented study reveals a complex and multifaceted relationship between ESR1 isoforms, the S6K1 signaling pathway, and key aspects of MCF-7 cell behavior. It was demonstrated that complete inactivation of full-length p66 ESR1 leads to a significant decrease in S6K1 expression, which, in turn, negatively impacts cell proliferation and motility. Interestingly, the increased expression of the p46 ESR1 isoform, despite maintaining overall S6K1 levels, disrupts its activation dynamics, suggesting a possible regulatory role for p46 ESR1 in modulating cellular responses to growth factors. Conclusions. These findings are crucial for understanding the mechanisms by which different estrogen receptor isoforms can influence the growth, aggressiveness, and metastatic potential of breast cancer cells, particularly through their effect on S6K1 expression and activity. Further research is needed to elucidate the precise molecular mechanisms by which p46 ESR1 modulates S6K1 activation.
Keywords: ESR1, CRISPR/Cas9, MCF-7 cells, S6K1, epithelial-mesenchymal transition
Full text: (PDF, in English)

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