CRISPR/Cas9-mediated Bag-1 knockout increased mesenchymal characteristics of MCF-7 cells via Akt hyperactivation-mediated actin cytoskeleton remodeling

PLoS One. 2022 Jan 7;17(1):e0261062. doi: 10.1371/journal.pone.0261062. eCollection 2022.


Bag-1 protein is a crucial target in cancer to increase the survival and proliferation of cells. The Bag-1 expression is significantly upregulated in primary and metastatic cancer patients compared to normal breast tissue. Overexpression of Bag-1 decreases the efficiency of conventional chemotherapeutic drugs, whereas Bag-1 silencing enhances the apoptotic efficiency of therapeutics, mostly in hormone-positive breast cancer subtypes. In this study, we generated stable Bag-1 knockout (KO) MCF-7 breast cancer cells to monitor stress-mediated cellular alterations in comparison to wild type (wt) and Bag-1 overexpressing (Bag-1 OE) MCF-7 cells. Validation and characterization studies of Bag-1 KO cells showed different cellular morphology with hyperactive Akt signaling, which caused stress-mediated actin reorganization, focal adhesion decrease and led to mesenchymal characteristics in MCF-7 cells. A potent Akt inhibitor, MK-2206, suppressed mesenchymal transition in Bag-1 KO cells. Similar results were obtained following the recovery of Bag-1 isoforms (Bag-1S, M, or L) in Bag-1 KO cells. The findings of this study emphasized that Bag-1 is a mediator of actin-mediated cytoskeleton organization through regulating Akt activation.

MeSH terms

  • Actin Cytoskeleton / genetics
  • Actin Cytoskeleton / metabolism*
  • Actins / metabolism
  • Apoptosis / genetics
  • Breast Neoplasms / pathology
  • CRISPR-Cas Systems
  • Cell Line, Tumor
  • Cell Survival
  • DNA-Binding Proteins / genetics
  • DNA-Binding Proteins / metabolism*
  • Epithelial-Mesenchymal Transition / physiology
  • Female
  • Humans
  • MCF-7 Cells / metabolism
  • Proto-Oncogene Proteins c-akt / genetics
  • Proto-Oncogene Proteins c-akt / metabolism*
  • Signal Transduction / genetics
  • Transcription Factors / genetics
  • Transcription Factors / metabolism*


  • Actins
  • BCL2-associated athanogene 1 protein
  • DNA-Binding Proteins
  • Transcription Factors
  • Proto-Oncogene Proteins c-akt

Grants and funding

This research was funded by Istanbul Technical University (Internal grant no: TDK-2017-40794) and Istanbul Kultur University, Scientific Research Projects Support Center. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.