BACKGROUND: Prostate cancer ranks as the second most frequently diagnosed cancer in men worldwide. Recent research highlights the crucial roles IL6ST-mediated signaling pathways play in the development and progression of various cancers, particularly through hyperactivated STAT3 signaling. However, the molecular programs mediated by IL6ST/STAT3 in prostate cancer are poorly understood. METHODS: To investigate the role of IL6ST signaling, we constitutively activated IL6ST signaling in the prostate epithelium of a Pten-deficient prostate cancer mouse model in vivo and examined IL6ST expression in large cohorts of prostate cancer patients. We complemented these data with in-depth transcriptomic and multiplex histopathological analyses. RESULTS: Genetic cell-autonomous activation of the IL6ST receptor in prostate epithelial cells triggers active STAT3 signaling and significantly reduces tumor growth in vivo. Mechanistically, genetic activation of IL6ST signaling mediates senescence via the STAT3/ARF/p53 axis and recruitment of cytotoxic T-cells, ultimately impeding tumor progression. In prostate cancer patients, high IL6ST mRNA expression levels correlate with better recurrence-free survival, increased senescence signals and a transition from an immune-cold to an immune-hot tumor. CONCLUSIONS: Our findings demonstrate a context-dependent role of IL6ST/STAT3 in carcinogenesis and a tumor-suppressive function in prostate cancer development by inducing senescence and immune cell attraction. We challenge the prevailing concept of blocking IL6ST/STAT3 signaling as a functional prostate cancer treatment and instead propose cell-autonomous IL6ST activation as a novel therapeutic strategy.
- MeSH
- inhibitor p16 cyklin-dependentní kinasy metabolismus genetika MeSH
- lidé MeSH
- modely nemocí na zvířatech MeSH
- myši MeSH
- nádorové buněčné linie MeSH
- nádorové mikroprostředí * MeSH
- nádorový supresorový protein p53 * metabolismus genetika MeSH
- nádory prostaty * patologie metabolismus genetika MeSH
- regulace genové exprese u nádorů MeSH
- signální transdukce * MeSH
- stárnutí buněk * MeSH
- transkripční faktor STAT3 * metabolismus MeSH
- zvířata MeSH
- Check Tag
- lidé MeSH
- mužské pohlaví MeSH
- myši MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
TP53 gene abnormalities represent the most important biomarker in chronic lymphocytic leukemia (CLL). Altered protein modifications could also influence p53 function, even in the wild-type protein. We assessed the impact of p53 protein phosphorylations on p53 functions as an alternative inactivation mechanism. We studied p53 phospho-profiles induced by DNA-damaging agents (fludarabine, doxorubicin) in 71 TP53-intact primary CLL samples. Doxorubicin induced two distinct phospho-profiles: profile I (heavily phosphorylated) and profile II (hypophosphorylated). Profile II samples were less capable of activating p53 target genes upon doxorubicin exposure, resembling TP53-mutant samples at the transcriptomic level, whereas standard p53 signaling was triggered in profile I. ATM locus defects were more common in profile II. The samples also differed in the basal activity of the hypoxia pathway: the highest level was detected in TP53-mutant samples, followed by profile II and profile I. Our study suggests that wild-type TP53 CLL cells with less phosphorylated p53 show TP53-mutant-like behavior after DNA damage. p53 hypophosphorylation and the related lower ability to respond to DNA damage are linked to ATM locus defects and the higher basal activity of the hypoxia pathway.
- MeSH
- ATM protein genetika metabolismus MeSH
- chronická lymfatická leukemie * genetika MeSH
- doxorubicin farmakologie MeSH
- fosforylace MeSH
- geny p53 MeSH
- hypoxie genetika MeSH
- lidé MeSH
- nádorový supresorový protein p53 * metabolismus MeSH
- poškození DNA MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
The cytokine interleukin-6 (IL-6) has considerable pro-inflammatory properties and is a driver of many physiological and pathophysiological processes. Cellular responses to IL-6 are mediated by membrane-bound or soluble forms of the IL-6 receptor (IL-6R) complexed with the signal-transducing subunit gp130. While expression of the membrane-bound IL-6R is restricted to selected cell types, soluble IL-6R (sIL-6R) enables gp130 engagement on all cells, a process termed IL-6 trans-signalling and considered to be pro-inflammatory. sIL-6R is predominantly generated through proteolytic processing by the metalloproteinase ADAM17. ADAM17 also liberates ligands of the epidermal growth factor receptor (EGFR), which is a prerequisite for EGFR activation and results in stimulation of proliferative signals. Hyperactivation of EGFR mostly due to activating mutations drives cancer development. Here, we reveal an important link between overshooting EGFR signalling and the IL-6 trans-signalling pathway. In epithelial cells, EGFR activity induces not only IL-6 expression but also the proteolytic release of sIL-6R from the cell membrane by increasing ADAM17 surface activity. We find that this derives from the transcriptional upregulation of iRhom2, a crucial regulator of ADAM17 trafficking and activation, upon EGFR engagement, which results in increased surface localization of ADAM17. Also, phosphorylation of the EGFR-downstream mediator ERK mediates ADAM17 activity via interaction with iRhom2. In sum, our study reveals an unforeseen interplay between EGFR activation and IL-6 trans-signalling, which has been shown to be fundamental in inflammation and cancer.
- MeSH
- cytokinový receptor gp130 genetika MeSH
- epitelové buňky metabolismus MeSH
- erbB receptory genetika metabolismus MeSH
- interleukin-6 * genetika metabolismus MeSH
- lidé MeSH
- protein ADAM17 * MeSH
- signální transdukce * genetika MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
BACKGROUND & AIMS: Patient-derived organoid cancer models are generated from epithelial tumor cells and reflect tumor characteristics. However, they lack the complexity of the tumor microenvironment, which is a key driver of tumorigenesis and therapy response. Here, we developed a colorectal cancer organoid model that incorporates matched epithelial cells and stromal fibroblasts. METHODS: Primary fibroblasts and tumor cells were isolated from colorectal cancer specimens. Fibroblasts were characterized for their proteome, secretome, and gene expression signatures. Fibroblast/organoid co-cultures were analyzed by immunohistochemistry and compared with their tissue of origin, as well as on gene expression levels compared with standard organoid models. Bioinformatics deconvolution was used to calculate cellular proportions of cell subsets in organoids based on single-cell RNA sequencing data. RESULTS: Normal primary fibroblasts, isolated from tumor adjacent tissue, and cancer associated fibroblasts retained their molecular characteristics in vitro, including higher motility of cancer associated compared with normal fibroblasts. Importantly, both cancer-associated fibroblasts and normal fibroblasts supported cancer cell proliferation in 3D co-cultures, without the addition of classical niche factors. Organoids grown together with fibroblasts displayed a larger cellular heterogeneity of tumor cells compared with mono-cultures and closely resembled the in vivo tumor morphology. Additionally, we observed a mutual crosstalk between tumor cells and fibroblasts in the co-cultures. This was manifested by considerably deregulated pathways such as cell-cell communication and extracellular matrix remodeling in the organoids. Thrombospondin-1 was identified as a critical factor for fibroblast invasiveness. CONCLUSION: We developed a physiological tumor/stroma model, which will be vital as a personalized tumor model to study disease mechanisms and therapy response in colorectal cancer.
- MeSH
- fibroblasty asociované s nádorem * metabolismus MeSH
- fibroblasty metabolismus MeSH
- kokultivační techniky MeSH
- kolorektální nádory * patologie MeSH
- lidé MeSH
- nádorové mikroprostředí MeSH
- organoidy metabolismus MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
The binding of microRNAs (miRNAs) to their target sites is a complex process, mediated by the Argonaute (Ago) family of proteins. The prediction of miRNA:target site binding is an important first step for any miRNA target prediction algorithm. To date, the potential for miRNA:target site binding is evaluated using either co-folding free energy measures or heuristic approaches, based on the identification of binding 'seeds', i.e., continuous stretches of binding corresponding to specific parts of the miRNA. The limitations of both these families of methods have produced generations of miRNA target prediction algorithms that are primarily focused on 'canonical' seed targets, even though unbiased experimental methods have shown that only approximately half of in vivo miRNA targets are 'canonical'. Herein, we present miRBind, a deep learning method and web server that can be used to accurately predict the potential of miRNA:target site binding. We trained our method using seed-agnostic experimental data and show that our method outperforms both seed-based approaches and co-fold free energy approaches. The full code for the development of miRBind and a freely accessible web server are freely available.
Cardiac pathologies are characterized by intense remodeling of the extracellular matrix (ECM) that eventually leads to heart failure. Cardiomyocytes respond to the ensuing biomechanical stress by reexpressing fetal contractile proteins via transcriptional and posttranscriptional processes, such as alternative splicing (AS). Here, we demonstrate that the heterogeneous nuclear ribonucleoprotein C (hnRNPC) is up-regulated and relocates to the sarcomeric Z-disc upon ECM pathological remodeling. We show that this is an active site of localized translation, where the ribonucleoprotein associates with the translation machinery. Alterations in hnRNPC expression, phosphorylation, and localization can be mechanically determined and affect the AS of mRNAs involved in mechanotransduction and cardiovascular diseases, including Hippo pathway effector Yes-associated protein 1. We propose that cardiac ECM remodeling serves as a switch in RNA metabolism by affecting an associated regulatory protein of the spliceosome apparatus. These findings offer new insights on the mechanism of mRNA homeostatic mechanoregulation in pathological conditions.
- MeSH
- buněčný převod mechanických signálů MeSH
- extracelulární matrix metabolismus MeSH
- heterogenní jaderné ribonukleoproteiny skupiny C * metabolismus MeSH
- kardiomyocyty metabolismus MeSH
- lidé MeSH
- messenger RNA genetika metabolismus MeSH
- srdeční selhání * metabolismus MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
OBJECTIVE: GDF11 is a member of the TGF-β superfamily that was recently implicated as potential "rejuvenating" factor, which can ameliorate metabolic disorders. The main objective of the presented study was to closely characterize the role of GDF11 signaling in the glucose homeostasis and in the differentiation of white adipose tissue. METHODS: We performed microscopy imaging, biochemical and transcriptomic analyses of adipose tissues of 9 weeks old ob/ob mice and murine and human pre-adipocyte cell lines. RESULTS: Our in vivo experiments employing GDF11 treatment in ob/ob mice showed improved glucose/insulin homeostasis, decreased weight gain and white adipocyte size. Furthermore, GDF11 treatment inhibited adipogenesis in pre-adipocytes by ALK5-SMAD2/3 activation in cooperation with the WNT/β-catenin pathway, whose inhibition resulted in adipogenic differentiation. Lastly, we observed significantly elevated levels of the adipokine hormone adiponectin and increased glucose uptake by mature adipocytes upon GDF11 exposure. CONCLUSION: We show evidence that link GDF11 to adipogenic differentiation, glucose, and insulin homeostasis, which are pointing towards potential beneficial effects of GDF11-based "anti-obesity" therapy.
- MeSH
- adipogeneze * MeSH
- adiponektin metabolismus MeSH
- beta-katenin * metabolismus MeSH
- buněčná diferenciace fyziologie MeSH
- glukosa metabolismus MeSH
- inzulin metabolismus MeSH
- kostní morfogenetické proteiny metabolismus MeSH
- lidé MeSH
- myši MeSH
- protein Smad2 MeSH
- protein Smad3 MeSH
- receptory regulované proteiny Smad MeSH
- růstové diferenciační faktory metabolismus MeSH
- signální dráha Wnt MeSH
- TGF-beta receptor I. typu MeSH
- transformující růstový faktor beta metabolismus MeSH
- tukové buňky metabolismus MeSH
- zvířata MeSH
- Check Tag
- lidé MeSH
- myši MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
Toll-like receptor 3 (TLR3) is an endosomal receptor expressed in several immune and epithelial cells. Recent studies have highlighted its expression also in solid tumors, including prostate cancer (PCa), and have described its role primarily in the proinflammatory response and induction of apoptosis. It is up-regulated in some castration-resistant prostate cancers. However, the role of TLR3 in prostate cancer progression remains largely unknown. The current study experimentally demonstrated that exogenous TLR3 activation in PCa cell lines leads to a significant induction of secretion of the cytokines IL-6, IL-8, and interferon-β, depending on the model and chemoresistance status. Transcriptomic analysis of TLR3-overexpressing cells revealed a functional program that is enriched for genes involved in the regulation of cell motility, migration, and tumor invasiveness. Increased motility, migration, and invasion in TLR3-overexpressing cell line were confirmed by several in vitro assays and using an orthotopic prostate xenograft model in vivo. Furthermore, TLR3-ligand induced apoptosis via cleavage of caspase-3/7 and poly (ADP-ribose) polymerase, predominantly in TLR3-overexpressing cells. These results indicate that TLR3 may be involved in prostate cancer progression and metastasis; however, it might also represent an Achilles heel of PCa, which can be exploited for targeted therapy.
- MeSH
- apoptóza MeSH
- lidé MeSH
- nádorové buněčné linie MeSH
- nádory prostaty * patologie MeSH
- poly I-C farmakologie MeSH
- prostata patologie MeSH
- toll-like receptor 3 * genetika metabolismus MeSH
- zvířata MeSH
- Check Tag
- lidé MeSH
- mužské pohlaví MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
The identification of the essential role of cyclin-dependent kinases (CDKs) in the control of cell division has prompted the development of small-molecule CDK inhibitors as anticancer drugs. For many of these compounds, the precise mechanism of action in individual tumor types remains unclear as they simultaneously target different classes of CDKs - enzymes controlling the cell cycle progression as well as CDKs involved in the regulation of transcription. CDK inhibitors are also capable of activating p53 tumor suppressor in tumor cells retaining wild-type p53 gene by modulating MDM2 levels and activity. In the current study, we link, for the first time, CDK activity to the overexpression of the MDM4 (MDMX) oncogene in cancer cells. Small-molecule drugs targeting the CDK9 kinase, dinaciclib, flavopiridol, roscovitine, AT-7519, SNS-032, and DRB, diminished MDM4 levels and activated p53 in A375 melanoma and MCF7 breast carcinoma cells with only a limited effect on MDM2. These results suggest that MDM4, rather than MDM2, could be the primary transcriptional target of pharmacological CDK inhibitors in the p53 pathway. CDK9 inhibitor atuveciclib downregulated MDM4 and enhanced p53 activity induced by nutlin-3a, an inhibitor of p53-MDM2 interaction, and synergized with nutlin-3a in killing A375 melanoma cells. Furthermore, we found that human pluripotent stem cell lines express significant levels of MDM4, which are also maintained by CDK9 activity. In summary, we show that CDK9 activity is essential for the maintenance of high levels of MDM4 in human cells, and drugs targeting CDK9 might restore p53 tumor suppressor function in malignancies overexpressing MDM4.
- MeSH
- cyklin-dependentní kinasa 9 antagonisté a inhibitory metabolismus MeSH
- genetická transkripce MeSH
- imidazoly farmakologie MeSH
- inhibitory proteinkinas farmakologie MeSH
- lidé MeSH
- melanom genetika metabolismus patologie MeSH
- MFC-7 buňky MeSH
- myši MeSH
- nádorové buněčné linie MeSH
- nádory prsu genetika metabolismus patologie MeSH
- piperaziny farmakologie MeSH
- pluripotentní kmenové buňky metabolismus MeSH
- proteiny buněčného cyklu biosyntéza genetika metabolismus MeSH
- protoonkogenní proteiny c-mdm2 biosyntéza genetika metabolismus MeSH
- protoonkogenní proteiny biosyntéza genetika metabolismus MeSH
- roskovitin farmakologie MeSH
- sulfonamidy farmakologie MeSH
- synergismus léků MeSH
- transfekce MeSH
- triaziny farmakologie MeSH
- zvířata MeSH
- Check Tag
- lidé MeSH
- myši MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
