TNF-α promotes TNBC aggressiveness by upregulating miR-5001-5p and inhibiting MNK2a–p38 MAPK signaling
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ABSTRACT: Triple-negative breast cancer (TNBC) has a greater invasive and metastatic potential than non-TNBC, leading to a poorer prognosis because of the absence of viable therapeutic targets. Tumor necrosis factor-alpha (TNF-α), which is aberrantly activated in TNBC, plays a pivotal role in TNBC metastasis and progression. The ability of TNF-α to promote TNBC progression is unique when compared with its ability to promote non-TNBC progression; however, the underlying mechanism remains unclear. TNF-α specifically enhanced the invasive and metastatic potential of TNBC compared with that of non-TNBC. Analysis of the differentially expressed miRNAs showed that TNF-α upregulated miR-5001-5p expression in TNBC cells. The results of transcriptomic sequencing combined with subsequent verification analysis indicated that MNK2a was significantly downregulated following miR-5001-5p overexpression. Evidence from dual-luciferase reporter assays confirmed that miR-5001-5p bound to the MNK2a 3' UTR region and inhibited the activation of the p38 MAPK pathway. Our results provide novel insights into the molecular mechanism by which TNF-α promotes epithelial–mesenchymal transition in TNBC through the TNF-α–miR-5001-5p–MNK2a–p38 MAPK signaling axis, eventually enhancing the invasive and metastatic potential of TNBC. We discovered a novel mechanism of invasion and metastasis in TNBC whereby TNF-α upregulated the expression of miR-5001-5p, which downregulated MNK2a by binding to its 3' UTR region. This inhibited the activation of the p38 MAPK pathway, following which MNK2a promoted epithelial–mesenchymal transition in TNBC. This mechanism offers a theoretical basis for TNBC-targeted therapy and also serves as a novel therapeutic target.
Project description:Oxaliplatin (oxPt) resistance in colorectal cancers (CRC) is a major unsolved problem. Consequently, predictive markers and a better understanding of resistance mechanisms are urgently needed. To investigate if the recently identified predictive miR-625-3p is functionally involved in oxPt resistance, stable and inducible models of miR-625-3p dysregulation were analyzed. Ectopic expression of miR-625-3p in CRC cells led to increased resistance towards oxPt. The mitogen-activated protein kinase (MAPK) kinase 6 (MAP2K6/MKK6) – an activator of p38 MAPK - was identified as a functional target of miR-625-3p, and, in agreement, was down-regulated in patients not responding to oxPt therapy. The miR-625-3p resistance phenotype could be reversed by anti-miR-625-3p treatment and by ectopic expression of a miR-625-3p insensitive MAP2K6 variant. Transcriptome, proteome and phosphoproteome profiles revealed inactivation of MAP2K6-p38 signaling as a possible driving force behind oxPt resistance. We conclude that miR-625-3p induces oxPt resistance by abrogating MAP2K6-p38 regulated apoptosis and cell cycle control networks.
Project description:Transmissible gastroenteritis virus (TGEV), a member of the coronaviridae family, could cause fatal diarrhea of piglets and result in numerous economic losses. Previous studies demonstrated that TGEV infection could lead to mitochondrial damage and up-regulate miR-4331 level. So miR-4331 may play an important regulatory role in the control of mitochondrial function. To explore the potential role of miR-4331 in mitochondrial damage, we adopted a strategy consisting of quantitative proteomic analysis of porcine kidney (PK-15) cells in response to miR-4331 and TGEV infection. Eventually, 69 differentially expressed proteins were gained. The target of miR-4331 was identified. The effects of miR-4331 and its target RB1 on mitochondrial Ca2+ level, mitochondrial membrane potential (MMP), interleukin-1 receptor accessory protein (IL1RAP), p38 MAPK signaling pathway were investigated. The results showed that miR-4331 elevated mitochondrial Ca2+ level, reduced MMP, targets Retinoblastoma 1 (RB1), up-regulated IL1RAP, and induced activation of p38 MAPK pathway during TGEV infection. RB1 was identified as the direct targets of miR-4331 and down-regulated IL1RAP, suppressed the activation of p38 MPAK, and attenuated TGEV-induced mitochondrial damage. In addition, IL1RAP played a positive role in activating p38 MAPK signaling and negative role in TGEV-induced mitochondrial damage. The data indicate that miR-4331 aggravates TGEV-induced mitochondrial damage by repressing expression of RB1, promoting IL1RAP, and activating p38 MAPK pathway.
Project description:Cells have the ability to respond and adapt to environmental changes through the activation of stress-activated protein kinases (SAPKs). Although it has been shown that p38 SAPK signalling participates in the regulation of gene transcription, there is not a comprehensive genome-wide transcription study reported to date describing neither the role of the p38 SAPK on the immediate response to stress and its kinetics nor a comparative vision of the genes that respond to different stimuli that activate the p38 SAPK. Here, we report a whole genome microarray analyses on wild type mouse embryonic fibroblasts (MEFs) treated with different p38 SAPK activators, namely the physiological cytokine TNF alpha, the protein synthesis inhibitor antibiotic anisomycin and osmostress. In addition, we have analysed the contribution of p38 alpha the major isoform of p38 present in MEF cells, in the overall transcription in response to those stimuli by both, the inhibition of p38 SAPK by using a chemical inhibitor (SB203580) and the use of p38 alpha knock out MEFs. Furthermore, we have analysed the kinetics of the gene expression response to osmostress by the p38 SAPK. Two samples have been analysed; wild type Mouse embryonic fibroblast (WT-MEFs) and MAPK p38alfa knock out MEFs (KO-MEFs) respectively treated with 11 and 4 different treatments. Each experiment was performed in duplicate and referenced to a pool of two non-treated WT MEFs.
Project description:Corticosteroids act on the glucocorticoid receptor (GR; NR3C1) to resolve inflammation and are routinely prescribed to breast cancer patients undergoing chemotherapy treatment to alleviate side effects. Triple negative breast cancers (TNBCs) account for 15-20% of diagnoses and lack expression of estrogen and progesterone receptors as well as amplified HER2, but often express high GR levels. GR is a mediator of TNBC progression to advanced metastatic disease, however the mechanisms underpinning this transition to more aggressive behavior remain elusive. We previously showed that tissue/cellular stress (hypoxia, chemotherapies) as well as factors in the tumor microenvironment (TGFβ, HGF) activate p38 MAPK, which phosphorylates GR on Ser134. In the absence of ligand, p-Ser134-GR further upregulates genes important for responses to cellular stress, including key components of the p38 MAPK pathway. Herein, we show that GR Ser134 is required for TNBC metastatic colonization to the lung. To understand the mechanisms of p-Ser134-GR action in the presence of GR agonists, we examined glucocorticoid-driven transcriptomes in CRISPR (knock-in) models of TNBC cells expressing wild-type or phospho-mutant (S134A) GR. We identified dexamethasone- and p-Ser134-GR-dependent regulation of specific gene sets controlling TNBC migration (NEDD9, CSF1, RUNX3) and metabolic adaptation (PDK4, PGK1, PFKFB4). TNBC cells harboring S134A GR displayed metabolic reprogramming that was phenocopied by PDK4 knockdown. PDK4 knockdown or chemical inhibition also blocked cancer cell migration. Our results reveal a convergence of GR agonists (i.e., host stress) with cellular stress signaling whereby pSer134-GR critically regulates TNBC metabolism, an exploitable target for the treatment of this deadly disease.
Project description:Carbon monoxide (CO) abrogates TNF-alpha mediated inflammatory responses in endothelial cells, yet, the underlying mechanism hereof is still elusive. We sought to explore potential mechanisms by which CO down-regulates VCAM-1 expression on TNF-alpha stimulated human umbilical vein endothelial cells (HUVEC). By genome-wide gene expression profiling and pathway analysis we studied the relevance of particular pathways for the anti-inflammatory effect of CO. In CO-releasing molecules-3 (CORM-3) stimulated HUVEC, significant changes in gene expression were found for genes implicated in the proteasome and porphyrine pathways. Although proteasome activities were increased by CORM-3, proteasome inhibitors did not abolish CORM-3‘s effect. Likewise, HO-1 inhibitors did not abrogate the ability of CORM-3 to down-regulate VCAM-1 expression. MAPK p38 was inhibited by CORM-3. Accordingly, VCAM-1 expression was down-regulated by the p38 inhibitor SB203580. Down-regulation of VCAM-1 by CORM-3 only occurred at concentrations that partly inhibit ATP production. Sodium azide and oligomycin paralleled the effect of CORM-3 in this regard. In conclusion, down-regulation of VCAM-1 by CORM-3 seems to be mediated via inhibition of p38 and mitochondrial respiration. Although CORM-3 up-regulates several genes in the ubiquitin proteasome sytem (UPS) or porphyrin pathway, there is no evidence that these changes are involved in the anti-inflammatory properties of CORM-3. In this study we focused on the potential of CORM-3 to downregulate the expression of TNF-alpha mediated inflammataroy genes
Project description:Oxaliplatin (oxPt) resistance in colorectal cancers (CRC) is a major unsolved problem. Consequently, predictive markers and a better understanding of resistance mechanisms are urgently needed. To investigate if the recently identified predictive miR-625-3p is functionally involved in oxPt resistance, stable and inducible models of miR-625-3p dysregulation were analyzed. Ectopic expression of miR-625-3p in CRC cells led to increased resistance towards oxPt. The mitogen-activated protein kinase (MAPK) kinase 6 (MAP2K6/MKK6) – an activator of p38 MAPK - was identified as a functional target of miR-625-3p, and, in agreement, was down-regulated in patients not responding to oxPt therapy. The miR-625-3p resistance phenotype could be reversed by anti-miR-625-3p treatment and by ectopic expression of a miR-625-3p insensitive MAP2K6 variant. Transcriptome, proteome and phosphoproteome profiles revealed inactivation of MAP2K6-p38 signaling as a possible driving force behind oxPt resistance. We conclude that miR-625-3p induces oxPt resistance by abrogating MAP2K6-p38 regulated apoptosis and cell cycle control networks. Experimental design for mass spectrometry SILAC experiments can be found at https://figshare.com/s/8e79f008e0e58ec6efc2 or https://doi.org/10.6084/m9.figshare.4888139
Project description:We developed a novel substrate-selective inhibitor of p38 MAPK, UM101, and compared its effects on TNF-induced gene expression by human lung microvascular endothelial cells (HMVECLs) with the prototypical p38 catalytic inhibitor, SB203580
Project description:Supporting microarray data for manuscript entitled "OSTEOPONTIN AND PAI-1 EXPRESSION IN MALIGNANT HYPERTENSION: SUPPRESSION BY p38 MAPK INHIBITORS" submitted to the HYPERTENSION journal. Experiment Overall Design: Male spontaneously hypertensive stroke-prone rats (SHR-SP) were obtained from Charles River (Raleigh, NC). At 11 weeks of age, the SHR-SP were randomized into 2 groups, and fed either powdered chow diet (Purina 5001) with water ad lib; or a high-salt/high-fat diet consisting of 1% NaCl in the drinking water and 24.5% fat in the chow (from Harlan TekLad, Madison, Wisconsin). 6 replicate animals per diet per time point.
Project description:From a previous microarray study we developed a small chondrogenesis model. We performed qPCR and measured how knockdown of miR-199a-5p or miR-199b-5p could modulate chondrogenesis. Several experiments were used to determine the parameters of this model. We utilised parameter scan and manual sliding to refine the model. Within are two models - an initial model which only comprises of genes which we have data for, and an enhanced model which expands of the initial model to make more predictions - e.g. how miR-140-5p is indirectly regulated by miR-199a-5p and miR-199b-5p.