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

Kilbas, Pelin Ozfiliz; Can, Nisan Denizce; Kizilboga, Tugba; Ezbercı, Fikret; Doganay, Levent; Arısan, Elif Damla; Doğanay, Gizem Dinler

doi:10.1371/journal.pone.0261062

Cited by 5 publications

(2 citation statements)

References 32 publications

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“…S1 ). Besides, increased ROS generation has been reported following BAG1 knockout in MCF-7 cells ( 34 ). We therefore measured ROS production in MCF-7 and T47D cells after X15695 treatment using the fluorescent probe H2DCF-DA and showed a significant dose-dependent ROS production in MCF-7 but not in T47D cells ( Fig.…”

Section: Resultsmentioning

confidence: 99%

Identification of an Imidazopyridine-based Compound as an Oral Selective Estrogen Receptor Degrader for Breast Cancer Therapy

Pan

Solozobova

Kuznik

et al. 2023

Cancer Research Communications

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The pro-oncogenic activities of estrogen receptor alpha (ER) drive breast cancer pathogenesis. Endocrine therapies that impair the production of estrogen or the action of the ER are therefore used to prevent primary disease metastasis. Although recent successes with ER degraders have been reported, there is still the need to develop further ER antagonists with additional properties for breast cancer therapy. We have previously described a benzothiazole compound A4B17 that inhibits the proliferation of androgen receptor positive (AR+) prostate cancer cells by disrupting the interaction of the cochaperone BAG1 with the AR. A4B17 was also found to inhibit the proliferation of ER+ breast cancer cells. Using a scaffold hopping approach, we report here a group of small molecules with imidazopyridine scaffolds that are more potent and efficacious than A4B17. The prototype molecule X15695 efficiently degraded ER and attenuated estrogen-mediated target gene expression as well as transactivation by the AR. X15695 also disrupted key cellular protein-protein interactions such as BAG1-mortalin (GRP75) interaction as well as wild-type p53-mortalin or mutant p53-BAG2 interactions. These activities together reactivated p53 and resulted in cell cycle block and the induction of apoptosis. When administered orally to in vivo tumor xenograft models, X15695 potently inhibited the growth of breast tumor cells but less efficiently the growth of prostate tumor cells. We therefore identify X15695 as an oral selective ER degrader and propose further development of this compound for therapy of ER+ breast cancers.

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Section: Resultsmentioning

confidence: 99%

Identification of an Imidazopyridine-based Compound as an Oral Selective Estrogen Receptor Degrader for Breast Cancer Therapy

Pan

Solozobova

Kuznik

et al. 2023

Cancer Research Communications

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“…One potential limitation of these studies, specific to our LNCaP95 CRISPR clones, is the challenges of a heterogenous cell population giving rise to biological differences independent of the genomic manipulation performed (59). Interestingly, studies in breast cancer cell line models have demonstrated differential response in growth to BAG-1 knockdown and it maybe that the biological background is important for sensitivity to BAG-1 abrogation which will be important to understand in the context of prostate cancer (58,60). This finding is important as drugs targeting the BAG domain would presumably impact all three isoforms, and not resemble the impact of BAG-1L specific knockouts or mutations previously described (14)(15)(16)(17).…”

Section: Discussionmentioning

confidence: 99%

Targeting the BAG-1 family of co-chaperones in lethal prostate cancer

Neeb¹,

Figueiredo²,

Bogdan³

et al. 2022

Preprint

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Therapies that abrogate persistent androgen receptor (AR) signaling in castration resistant prostate cancer (CRPC) remain an unmet clinical need. The N-terminal domain (NTD) of the AR drives transcriptional activity in CRPC but is intrinsically disordered and remains a challenging therapeutic target. Therefore, inhibiting critical co-chaperones, such as BAG-1L, is an attractive alternative strategy. We performed druggability analyses demonstrating the BAG domain to be a challenging drug target. Thio-2, a tool compound, has been reported to bind the BAG domain of BAG-1L and inhibit BAG-1L-mediated AR transactivation. However, despite these data, the mechanism of action of Thio-2 is poorly understood and the BAG domain which is present in all BAG-1 isoforms has not been validated as a therapeutic target. Herein, we demonstrate growth inhibiting activity of Thio-2 in CRPC cell lines and patient derived models with decreased AR genomic binding and AR signaling independent of BAG-1 isoform function. Furthermore, genomic abrogation of BAG-1 isoforms did not recapitulate the described Thio-2 phenotype, and NMR studies suggest that Thio-2 may bind the AR NTD, uncovering a potential alternative mechanism of action, although in the context of low compound solubility. Furthermore, BAG-1 isoform knockout mice are viable and fertile, in contrast to previous studies, and when crossed with prostate cancer mouse models, BAG-1 deletion does not significantly impact prostate cancer development and growth. Overall, these data demonstrate that Thio-2 inhibits AR signaling and growth in CRPC independent of BAG-1 isoforms, and unlike previous studies of the activated AR, therapeutic targeting of the BAG domain requires further validation before being considered a therapeutic strategy for the treatment of CRPC.

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Bag‐1‐mediated HSF1 phosphorylation regulates expression of heat shock proteins in breast cancer cells

Kizilboga,

Özden,

Can

et al. 2024

FEBS Open Bio

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According to the World Health Organization in 2022, 2.3 million women were diagnosed with breast cancer. Investigating the interaction networks between Bcl‐2‐associated athanogene (Bag)‐1 and other chaperone proteins may further the current understanding of the regulation of protein homeostasis in breast cancer cells and contribute to the development of treatment options. The present study aimed to determine the interactions between Bag‐1 and heat shock proteins (HSPs); namely, HSP90, HSP70 and HSP27, to elucidate their role in promoting heat shock factor‐1 (HSF1)‐dependent survival of breast cancer cells. HER2‐negative (MCF‐7) and HER2‐positive (BT‐474) cell lines were used to examine the impact of Bag‐1 expression on HSF1 and HSPs. We demonstrated that Bag‐1 overexpression promoted HER2 expression in breast cancer cells, thereby resulting in the concurrent constitutive activation of the HSF1–HSP axis. The activation of HSP results in the stabilization of several tumor‐promoting HSP clients such as AKT, mTOR and HSF1 itself, which substantially accelerates tumor development. Our results suggest that Bag‐1 can modulate the chaperone activity of HSPs, such as HSP27, by directly or indirectly regulating the phosphorylation of HSF1. This modulation of chaperone activity can influence the activation of genes involved in cellular homeostasis, thereby protecting cells against stress.

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

Cited by 5 publications

References 32 publications

Identification of an Imidazopyridine-based Compound as an Oral Selective Estrogen Receptor Degrader for Breast Cancer Therapy

Identification of an Imidazopyridine-based Compound as an Oral Selective Estrogen Receptor Degrader for Breast Cancer Therapy

Targeting the BAG-1 family of co-chaperones in lethal prostate cancer

Bag‐1‐mediated HSF1 phosphorylation regulates expression of heat shock proteins in breast cancer cells

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