scholarly journals The extracellular sulfatase SULF2 promotes liver tumorigenesis by stimulating assembly of a promoter-looping GLI1-STAT3 transcriptional complex

2020 ◽  
Vol 295 (9) ◽  
pp. 2698-2712 ◽  
Author(s):  
Ryan M. Carr ◽  
Paola A. Romecin Duran ◽  
Ezequiel J. Tolosa ◽  
Chenchao Ma ◽  
Abdul M. Oseini ◽  
...  

The expression of the extracellular sulfatase SULF2 has been associated with increased hepatocellular carcinoma (HCC) growth and poor patient survival. However, the molecular mechanisms underlying SULF2-associated tumor growth remain unclear. To address this gap, here we developed a transgenic mouse overexpressing Sulf2 in hepatocytes under the control of the transthyretin promoter. In this model, Sulf2 overexpression potentiated diethylnitrosamine-induced HCC. Further analysis indicated that the transcription factor GLI family zinc finger 1 (GLI1) mediates Sulf2 expression during HCC development. A cross of the Sulf2-overexpressing with Gli1-knockout mice revealed that Gli1 inactivation impairs SULF2-induced HCC. Transcriptomic analysis revealed that Sulf2 overexpression is associated with signal transducer and activator of transcription 3 (STAT3)-specific gene signatures. Interestingly, the Gli1 knockout abrogated SULF2-mediated induction of several STAT3 target genes, including suppressor of cytokine signaling 2/3 (Socs2/3); Pim-1 proto-oncogene, Ser/Thr kinase (Pim1); and Fms-related tyrosine kinase 4 (Flt4). Human orthologs were similarly regulated by SULF2, dependent on intact GLI1 and STAT3 functions in HCC cells. SULF2 overexpression promoted a GLI1-STAT3 interaction and increased GLI1 and STAT3 enrichment at the promoters of their target genes. Interestingly, the SULF2 overexpression resulted in GLI1 enrichment at select STAT3 consensus sites, and vice versa. siRNA-mediated STAT3 or GLI1 knockdown reduced promoter binding of GLI1 and STAT3, respectively. Finally, chromatin-capture PCR confirmed long-range co-regulation of SOCS2 and FLT3 through changes in promoter conformation. These findings define a mechanism whereby SULF2 drives HCC by stimulating formation of a GLI1-STAT3 transcriptional complex.

Cancers ◽  
2019 ◽  
Vol 11 (10) ◽  
pp. 1428 ◽  
Author(s):  
Sebastian Igelmann ◽  
Heidi Neubauer ◽  
Gerardo Ferbeyre

The Signal Transducer and Activator of Transcription (STAT)3 and 5 proteins are activated by many cytokine receptors to regulate specific gene expression and mitochondrial functions. Their role in cancer is largely context-dependent as they can both act as oncogenes and tumor suppressors. We review here the role of STAT3/5 activation in solid cancers and summarize their association with survival in cancer patients. The molecular mechanisms that underpin the oncogenic activity of STAT3/5 signaling include the regulation of genes that control cell cycle and cell death. However, recent advances also highlight the critical role of STAT3/5 target genes mediating inflammation and stemness. In addition, STAT3 mitochondrial functions are required for transformation. On the other hand, several tumor suppressor pathways act on or are activated by STAT3/5 signaling, including tyrosine phosphatases, the sumo ligase Protein Inhibitor of Activated STAT3 (PIAS3), the E3 ubiquitin ligase TATA Element Modulatory Factor/Androgen Receptor-Coactivator of 160 kDa (TMF/ARA160), the miRNAs miR-124 and miR-1181, the Protein of alternative reading frame 19 (p19ARF)/p53 pathway and the Suppressor of Cytokine Signaling 1 and 3 (SOCS1/3) proteins. Cancer mutations and epigenetic alterations may alter the balance between pro-oncogenic and tumor suppressor activities associated with STAT3/5 signaling, explaining their context-dependent association with tumor progression both in human cancers and animal models.


2020 ◽  
Author(s):  
Miriam Pagin ◽  
Simone Giubbolini ◽  
Cristiana Barone ◽  
Gaia Sambruni ◽  
Yanfen Zhu ◽  
...  

AbstractThe Sox2 transcription factor is necessary for the long-term self-renewal of neural stem cells (NSC). Its mechanism of action is still poorly defined. To identify molecules regulated by Sox2, and acting in mouse NSC maintenance, we transduced, individually or in combination, into Sox2-deleted NSC, genes whose expression is strongly downregulated following Sox2 loss (Fos, Jun, Egr2). Fos alone rescued long-term proliferation, as shown by in vitro cell growth and clonal analysis. Further, Fos requirement for efficient long-term proliferation was demonstrated by the strong reduction of NSC clones capable of long-term expansion following CRISPR/Cas9-mediated Fos inactivation. Previous work showed that the Suppressor of cytokine signaling 3 (Socs3) gene is strongly downregulated following Sox2 deletion, and its reexpression by lentiviral transduction rescues long-term NSC proliferation. Fos appears to be an upstream regulator of Socs3, possibly together with Jun and Egr2; indeed, Sox2 reexpression in Sox2-deleted NSC progressively activates both Fos and Socs3 expression; in turn, Fos transduction activates Socs3 expression. Based on available SOX2 ChIPseq and ChIA-PET data, as well as results from the literature, we propose a model whereby Sox2 is a direct activator of both Socs3 and Fos, as well as possibly Jun and Egr2; in turn, Fos, Jun and Egr2 may activate Socs3. These results provide the basis for developing a model of a network of interactions, regulating critical effectors of NSC proliferation and long-term maintenance.Significance statementProliferation and maintenance of NSC are essential during normal brain development, and, postnatally, for the maintenance of hippocampal function and memory until advanced age. Little is known about the molecular mechanisms that maintain the critical aspects of NSC biology (quiescence and proliferation) in postnatal age. Our work provides a methodology, transduction of genes deregulated following Sox2 deletion, that allows to test many candidate genes for their ability to sustain NSC proliferation. In principle, this may have interesting implications for identifying targets for pharmacological manipulations.


2018 ◽  
Vol 49 (6) ◽  
pp. 2382-2395 ◽  
Author(s):  
Qing Ou-yang ◽  
Xuzhi He ◽  
Anqi Yang ◽  
Bing Li ◽  
Minhui Xu

Background/Aims: Glioblastoma is the most common and aggressive brain tumor and carries a poor prognosis. Previously, we found that neurotensin receptor 1 (NTSR1) contributes to glioma progression, but the underlying mechanisms of NTSR1 in glioblastoma invasion remain to be clarified. The aim of this study was to investigate the molecular mechanisms of NTSR1 in glioblastoma invasion. Methods: Cell migration and invasion were evaluated using wound-healing and transwell assays. Cell proliferation was detected using CCK-8. The expression of NTSR1, Jun, and suppressor of cytokine signaling 6 (SOCS6) was detected using western blotting. The expression of miR-494 was detected by Quantitative real-time PCR. Chromatin immunoprecipitation assay was performed to examine the interaction between Jun and miR-494 promoter. Dual-luciferase reporter assay and western blotting were performed to identify the direct regulation of SOCS6 by miR-494. An orthotopic xenograft mouse model was conducted to assess tumor growth and invasion. Results: NTSR1 knockdown attenuated the invasion of glioblastoma cells. Jun was positively regulated by NTSR1, which promoted miR-494 expression through binding to miR-494 promoter. SOCS6 was confirmed as a direct target of miR-494, thus, NTSR1-induced miR-494 upregulation resulted in SOCS6 downregulation. Both miR-494 and SOCS6 were involved in the NTSR1-induced invasion of glioblastoma cells. In vivo, tumor invasion and growth were inhibited by NTSR1 knockdown, but were restored with miR-494 overexpression. Conclusion: NTSR1 knockdown inhibited glioblastoma invasion via the Jun/miR-494/SOCS6 axis.


2008 ◽  
Vol 105 (46) ◽  
pp. 18012-18017 ◽  
Author(s):  
Jun Kohyama ◽  
Takuro Kojima ◽  
Eriko Takatsuka ◽  
Toru Yamashita ◽  
Jun Namiki ◽  
...  

Neural stem/progenitor cells (NSCs/NPCs) give rise to neurons, astrocytes, and oligodendrocytes. It has become apparent that intracellular epigenetic modification including DNA methylation, in concert with extracellular cues such as cytokine signaling, is deeply involved in fate specification of NSCs/NPCs by defining cell-type specific gene expression. However, it is still unclear how differentiated neural cells retain their specific attributes by repressing cellular properties characteristic of other lineages. In previous work we have shown that methyl-CpG binding protein transcriptional repressors (MBDs), which are expressed predominantly in neurons in the central nervous system, inhibit astrocyte-specific gene expression by binding to highly methylated regions of their target genes. Here we report that oligodendrocytes, which do not express MBDs, can transdifferentiate into astrocytes both in vitro (cytokine stimulation) and in vivo (ischemic injury) through the activation of the JAK/STAT signaling pathway. These findings suggest that differentiation plasticity in neural cells is regulated by cell-intrinsic epigenetic mechanisms in collaboration with ambient cell-extrinsic cues.


2021 ◽  
Vol 2021 ◽  
pp. 1-9
Author(s):  
Hao Zhang ◽  
Ming-Huang Gao ◽  
Yang Chen ◽  
Tao Liu

Background. Being a traditional Chinese medicine, Geranium wilfordii Maxim (GWM) is used for the treatment of various infectious diseases, and its main active ingredients are the polyphenolic substances such as polyphenols quercetin, corilagin, and geraniin. Previous studies have demonstrated the anti-HSV-1 viral activity of these three main ingredients. Through employing a network pharmacological method, the authors of the present research intend to probe the mechanism of GWM for the therapeutic treatment of HSV-2 infection. Methods. The bioactive substances and related targets of GWM were obtained from the TCMSP database. Gene expression discrepancy for HSV-2 infection was obtained from dataset GSE18527. Crossover genes between disease target genes and GWM target genes were gained via Circos package. Distinctively displayed genes (DDGs) during HSV-2 infection were uploaded to the Metascape database with GWM target genes for further analysis. The tissue-specific distribution of the genes was obtained by uploading the genes to the PaGenBase database. Ingredient-gene-pathway (IGP) networks were constructed using Cytoscape software. Molecular docking investigations were carried out utilizing AutoDock Vina software. Results. Nine actively involved components were retrieved from the TCMSP database. After taking the intersection among 153 drug target genes and 83 DDGs, 7 crossover genes were screened. Gene enrichment analysis showed that GWM treatment of HSV-2 infection mainly involves cytokine signaling in the immune system, response to virus, epithelial cell differentiation, and type II interferon signaling (IFNG). One hub, three core objectives, and two critical paths were filtered out from the built network. Geraniin showed strong binding activity with HSV-2 gD protein and STING protein in molecular docking. Conclusions. This network pharmacological study provides a fundamental molecular mechanistic exploration of GWM for the treatment of HSV-2 infection.


2018 ◽  
Vol 315 (4) ◽  
pp. G443-G453 ◽  
Author(s):  
Xia Lin ◽  
Li Chen ◽  
Haiyan Li ◽  
Yu Liu ◽  
Yanhong Guan ◽  
...  

Liver regeneration after two-thirds partial hepatectomy (PH) is a clinically significant repair process for restoring proper liver architecture. Although microRNA-155 (miR-155) has been found to serve as a crucial microRNA regulator that controls liver cell function and proliferation, little is known about its specific role in the regenerating liver. Using a mouse model with miR-155 overexpression or miR-155 knockout, we investigated the molecular mechanisms of miR-155 in liver regeneration. We found a marked induction of miR-155 in C57BL/6 mice after PH. Furthermore, RL-m155 mice showed enhanced liver regeneration as a result of accelerated progression of hepatocytes into the cell cycle, mainly through an increase in cyclin levels. However, proliferation of hepatocytes was delayed in miR-155-deficient livers. Expression of suppressor of cytokine signaling 1 (SOCS1) was dramatically downregulated in the process of liver regeneration, and enhancement of SOCS1 contributed to impaired proliferation of hepatocytes. Additionally, in vitro and in vivo experiments showed that adenovirus- or adeno-associated virus-mediated overexpression of SOCS1 attenuated improved liver regeneration induced by miR-155 overexpression. Our study shows that miR-155 is a pro-proliferative regulator in liver regeneration by facilitating the cell cycle and directly targeting SOCS1. NEW & NOTEWORTHY Our findings suggest a microRNA-155 (miR-155)-mediated positive regulation pattern in liver regeneration. A series of in vivo and in vitro studies showed that miR-155 upregulation enhanced partial hepatectomy-induced proliferation of hepatocytes by promoting the cell cycle without inducing DNA damage or apoptosis. Suppressor of cytokine signaling 1, a target gene of miR-155, antagonized the proliferation-promoting effect of miR-155. Therefore, pharmacological intervention targeting miR-155 may be therapeutically beneficial in various liver diseases.


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