The effect of knockdown of amphiregulin or SGK3 on global gene expression in letrozole resistant breast cancer cells
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ABSTRACT:
ORGANISM(S): Homo sapiens
PROVIDER: GSE148800 | GEO | 2020/04/23
REPOSITORIES: GEO
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Project description:The effect of knockdown of amphiregulin or SGK3 on global gene expression in letrozole resistant breast cancer cells
| PRJNA625749 | ENA
Project description:SGK3 is a PX domain containing protein kinase activated at endosomes downstream of Class 1 and 3 PI3K family members by growth factors and oncogenic mutations. SGK3 plays a key role in mediating resistance of breast cancer to Class 1 PI3K or Akt inhibitors, by substituting for loss of Akt and restoring proliferative pathways such as mTORC1 signaling. Here we describe the development of SGK3-PROTAC1, a Proteolysis Targeting Chimera (PROTAC) compound formed by the fusion of the 308-R SGK3 inhibitor with the VH032 VHL binding ligand via a 13-atom linker. In HEK293 cells, 0.3 µM SGK3-PROTAC1 induced 50% degradation of endogenous SGK3 within 2 hours, with maximal 85% degradation observed within 8 hours, accompanied by a loss of phosphorylation of NDRG1, an SGK3 substrate. SGK3-PROTAC1 did not degrade closely related SGK1 and SGK2 isoforms and proteomic analysis in HEK293 cells revealed that SGK3 was the only cellular protein whose cellular levels was significantly reduced following treatment with SGK3-PROTAC1. Low doses of SGK3-PROTAC1 (0.1-0.3 µM) restored sensitivity of SGK3 dependent ZR-75-1 and CAMA-1 breast cancer cells to Akt (AZD5363) and PI3K (GDC0941) inhibitors, under conditions which an epimer analogue incapable of binding to the VHL E3 ligase had no impact. SGK3-PROTAC1 suppressed proliferation of ZR-75-1 and CAMA-1 cancer cell lines treated with a PI3K inhibitor (GDC0941) more effectively than could be achieved by a conventional SGK isoform inhibitor (14H). This work provides a further example of the benefit of the PROTAC approach in targeting protein kinase signaling pathways with greater efficacy and selectivity than can be achieved with conventional inhibitors. SGK3-PROTAC1 will be an important reagent to explore the roles of the SGK3 pathway.
2019-11-12 | PXD013779 | Pride
Project description:Excessive glucocorticoid exposure is associated with significant metabolic side effects, partly attributed to the transcriptional regulation of adipogenesis by the Glucocorticoid receptor (GR). However, emerging evidence suggests the involvement of alternative pathways beyond GR activation, which are inadequately explored. Through quantitative phosphoproteomics analysis, we identified a significant enrichment of rapidly phosphorylated proteins harboring the RxxS motif following glucocorticoid exposure. Notably, a subset of these proteins undergoes phosphorylation at the RxxS motif by Serum- and glucocorticoid-induced kinase 3 (SGK3) upon glucocorticoid stimulation in preadipocytes. SGK3 emerges as a critical mediator of glucocorticoid-induced preadipocyte differentiation, supported by genetic ablation and pharmacological inhibition experiments that demonstrate impaired adipogenesis both in vitro and in vivo. Mechanistically, upon glucocorticoid stimulation, SGK3 translocates to the nucleus and directly interacts with the core ATPase subunit of the BAF chromatin remodeling complex, BRG1, leading to phosphorylation at threonine 428 and serine 1417 residues. This phosphorylation event prevents proteasomal degradation of BRG1, facilitating chromatin remodeling essential for adipogenesis. Furthermore, Sgk3 knockout mice exhibit resistance to obesity induced by either glucocorticoids or a high-fat diet (HFD). These findings illuminate novel roles of glucocorticoids beyond GR-mediated transcriptional control, highlighting SGK3 as a promising therapeutic target for mitigating metabolic side effects associated with glucocorticoid therapy.
2025-07-15 | GSE268382 | GEO
Project description:Serum- and glucocorticoid-regulated kinase 3 (Sgk3) is activated by the phospholipid 19 phosphatidylinositol-3-phosphate (PI3P) downstream of growth factor signaling and 20 by Vps34-mediated PI3P production during autophagy. Upregulation of Sgk3 activity 21 has been linked to a number of human cancers due to its overlapping substrate 22 specificity with Akt. Here, we show that Sgk3 is regulated by a combination of 23 phosphorylation and allosteric activation by PI3P. We demonstrate that Sgk3 is 24 specifically activated by PI3P and that PI3P binding induces large conformational 25 changes in Sgk3. Using Vps34 and liposomes containing phosphatidylinositol, we 26 reconstitute Sgk3 signaling via Vps34-mediated PI3P synthesis in vitro. In addition to 27 defining the mechanism of Sgk3 activation by PI3P, our findings open up potential 28 therapeutic avenues in allosteric inhibitor development to target Sgk3 in cancer.
2021-09-22 | PXD025327 | Pride
Project description:Cellular senescence is an irreversible growth arrest with a highly dynamic secretome, termed the senescence-associated secretory phenotype (SASP). Senescence has been implicated in somatic reprogramming to pluripotency. The cell-intrinsic proliferation arrest is a barrier for reprogramming, whereas the SASP facilitates the cell fate conversion in nonsenescent cells. However, the mechanisms by which reprogramming-induced senescence regulates cell plasticity are not well understood. Here, we have further investigated how the heterogeneity of paracrine senescence impacts reprogramming. We show that senescence promotes in vitro reprogramming in a stress-dependent manner. We identified a catalog of SASP factors and pathways potentially involved in the cell fate conversion using an unbiased proteomic analysis. Amphiregulin (AREG), a growth factor frequently secreted by the senescent cells, promotes in vitro reprogramming by accelerating proliferation and MET via the EGFR signaling pathway. Of note, AREG treatment diminished the negative effect of donor age on reprogramming. Finally, AREG enhances in vivo reprogramming in the skeletal muscle. Hence, senescence could facilitate cellular plasticity via various SASP factors to promote reprogramming and tissue repair.
2022-07-28 | PXD028590 | Pride
Project description:Deregulation of the PI3K/Akt pathway is a common feature in many types of cancer. Recent data has demonstrated that prolonged inhibition of breast cancer cell lines with PI3K and Akt inhibitors leads to up-regulation and increased activity of the AGC kinase Serum and glucocorticoid activated kinase 3, SGK3, which in turn substitutes for Akt and leads to activation of mTORC1. SGK3 and Akt exhibit similar substrate specificity for Ser/Thr residues in the RxRxxS/T motif. However, SGK3 can be regulated by both PI3K class I and class III and possesses a unique PX domain, enabling it to bind to PI(3)P lipids in endosomes. Still, the known SGK3 substrates are either shared or have not been tested whether Akt can phosphorylate them. In the present study, we undertook genetic and pharmacologic phosphoproteomic screens to search for selective SGK3 substrates. We identified a significant number of potential in vivo SGK3 selective substrates, including the endosomal proteins STX7, STX12, RFIP4 and WDR44. In vitro phosphorylation studies demonstrated that these substrates were directly phosphorylated at the sites identified in vivo by SGK3 but, unlike all other SGK3 substrates reported, not by Akt. We provide evidence that endogenous STX7 and STX12 are physiological SGK3 substrates whose phosphorylation is potently stimulated by IGF1. Our data pinpoint that STX7 and STX12 are the first selective SGK3 substrates in vivo and this phosphorylation enhances their interaction with the respective SNARE complexes. Finally, we suggest that STX7 and STX12 phosphorylation can be utilised as in vivo biomarkers for SGK3 activity.
2020-05-26 | PXD014561 | Pride
Project description:In this study, we demonstrate that radiation induces the epidermal growth factor receptor (EGFR) ligand amphiregulin (AREG) in tumor cells, which stimulates distant metastasis proliferation in both patients and pre-clinical murine tumor models. Using single-cell RNAseq (sc-RNAseq), we characterized the effects of AREG-induction on immune cells in the lung metastatic microenvironment of B6 mice.
2025-02-27 | GSE250375 | GEO
Project description:The phosphorylation profile of Sgk3 protein expressed either in Sf9 insect cells or HEK 293T human cells was assessed by mass spectrometry.
2022-02-17 | PXD026281 | Pride
Project description:We analyzed the effect of tetracycline (Tet)-inducible amphiregulin (AREG) silencing on the transcriptome of immortalized human N/TERT keratinocytes in the presence or absence of exogenous rhEGF. Tetracycline-mediated AREG silencing significantly altered the expression of 2,331 genes, 623 of which were not normalized towards normal by treatment with EGF. Genes irreversibly up-regulated by suppression of AREG overlapped with genes involved in keratinocyte differentiation. A significant proportion of the irreversibly down-regulated genes featured upstream binding sites recognized by FoxM1
2016-06-23 | GSE70230 | GEO
Project description:Cancer-associated fibroblasts (CAFs) are a pivotal component of the tumor microenvironment, significantly contributing to the progression of esophageal squamous cell carcinoma (ESCC). Direct co-culture of human bone marrow-derived mesenchymal stem cells (MSCs), one of the origins of CAFs, with ESCC cell line, led to increased amphiregulin (AREG) expression and secretion in the ESCC cells. Consequently, the expression and phosphorylation of the AREG receptor EGFR were upregulated in co-cultured ESCC cells. Moreover, AREG treatment enhanced ESCC cell survival and migration through the EGFR-Erk/p38 signaling pathway. Immunohistochemical analysis of AREG using human ESCC tissues showed a positive correlation between the intensity of AREG expression in tumor invasive front and the expression level of the CAF marker FAP. Furthermore, bioinformatics database analysis confirmed a significant upregulation of AREG expression in ESCC tissues compared to normal tissues. These findings suggest that AREG is involved in CAF-mediated ESCC progression and could be a novel therapeutic target for ESCC.
2024-12-04 | GSE274064 | GEO