scholarly journals Snail upregulates FN and LEF transcription negatively feed backed by PPAR-gamma: a general model established for Snail to transactivate mesenchymal genes

Author(s):  
Tam Minh Ly ◽  
Yen-Cheng Chen ◽  
Ming-Che Lee ◽  
Chuan Chu Chen ◽  
Hsin-Hou Chang ◽  
...  

Abstract Background Snail (SNA) is responsible for epithelial mesenchymal transition, migration and metastasis of hepatocellular carcinoma. SNA represses the transcription of the essential epithelial marker such as E-cadherin and enhances mesenchymal markers including fibronectin and lymphoid enhancer-binding factor. Our previous studies indicated that SNA, in collaboration with EGR1 and SP1, may directly activate transcription of the mesenchymal markers, matrix degradation enzyme matrix metalloproteinases (MMP9) and zinc finger E-box binding homeobox 1 (ZEB1) in HepG2 cell stimulated by the phorbol ester tumor promoter 12-O-tetradecanoyl-phorbol 13-acetate (TPA). Besides, we pinpointed a SNA binding motif (TCACA) upstream of EGR1/SP1 overlapping region on promoters. In this study, we investigated whether LEF and FN are transcriptionally regulated by SNA in a similar fashion. Moreover, a general model for SNA-upregulated mesenchymal markers is proposed.Methods RT/PCR and Western blot were used for analyzing gene expression and shRNA technology for depleting SNA. Dual luciferase assay was used for promoter activation; deletion mapping and mutagenesis were used for confirming the indicated promoter region required for transcription activation. ChIP and EMSA were used for validating the binding of the indicated transcription factor on their putative motifs. Results SNA binding motif and E/S overlapping region are required for TPA-induced transcription of LEF and FN. These were supported by TPA-induced binding of SNA and EGR-1/SP-1 on indicated promoter regions. Moreover, a peroxisome proliferator-activated receptor γ motif upstream of SNA binding motif was found to be a negatively regulatory region in TPA-induced promoter activation of FN, LEF, MMP9 and ZEB1. This was supported by that co-treatment of a PPAR-g inhibitor, GW9662, and mutation of PPAR-g binding motif enhanced TPA-induced promoter activity and expression of the aforementioned genes whereas overexpression of PPAR-g reversed it. Moreover, comprehensive screening of the SNA-upregulated mesenchymal genes revealed similar sequence architecture on the promoter regions of the candidate genes: SNA binding motif (TCACA) coupled with a downstream EGR/SP1 overlapping region and an upstream PPAR-g binding motif. Among them COX2 and COL1A1 were found to potentially exhibit the same transcription mechanisms described above. Conclusions We established a general model for SNA-upregulated mesenchymal gene expressions negatively feed backed by PPAR-g.

Cells ◽  
2021 ◽  
Vol 10 (9) ◽  
pp. 2202 ◽  
Author(s):  
Tam Minh Ly ◽  
Yen-Cheng Chen ◽  
Ming-Che Lee ◽  
Chi-Tan Hu ◽  
Chuan-Chu Cheng ◽  
...  

SNA is one of the essential EMT transcriptional factors capable of suppressing epithelial maker while upregulating mesenchymal markers. However, the mechanisms for SNA to transactivate mesenchymal markers was not well elucidated. Recently, we demonstrated that SNA collaborates with EGR1 and SP1 to directly upregulate MMP9 and ZEB1. Remarkably, a SNA-binding motif (TCACA) upstream of EGR/SP1 overlapping region on promoters was identified. Herein, we examined whether four other mesenchymal markers, lymphoid enhancer-binding factor (LEF), fibronectin (FN), cyclooxygenase 2 (COX2), and collagen type alpha I (COL1A1) are upregulated by SNA in a similar fashion. Expectedly, SNA is essential for expression of these mesenchymal genes. By deletion mapping and site directed mutagenesis coupled with dual luciferase promoter assay, SNA-binding motif and EGR1/SP1 overlapping region are required for TPA-induced transcription of LEF, FN, COX2 and COL1A1. Consistently, TPA induced binding of SNA and EGR1/SP1 on relevant promoter regions of these mesenchymal genes using ChIP and EMSA. Thus far, we found six of the mesenchymal genes are transcriptionally upregulated by SNA in the same fashion. Moreover, comprehensive screening revealed similar sequence architectures on promoter regions of other SNA-upregulated mesenchymal markers, suggesting that a general model for SNA-upregulated mesenchymal genes can be established.


Author(s):  
Jung Bong Kim ◽  
Grace Kelly Lee ◽  
Hae-Yeong Kim ◽  
Heon Woong Kim ◽  
Hwan Hee Jang ◽  
...  

We investigated the effect and molecular mechanism of 24-MCF-induced PPAR-γ2 on angiogenesis-related genes in MCF7 cells. cDNA microarray, semi-quantitative reverse transcription (RT)-PCR, and western blotting revealed that 24-MCF mediated the expression of genes related to angiogenesis in MCF-7 cells. Luciferase reporter assay demonstrated that promoter activation of the LIF gene, an anti-angiogenesis factor, was increased upon PPAR-γ2 overexpression and 24-MCF treatment, whereas activation of HoxA7 and VEGF promoters, known pro-angiogenesis factors, decreased upon PPAR-γ2 overexpression and 24-MCF treatment. We identified PPAR-response elements (PPRE) located in the VEGF (-913 to +1), HoxA7 (-1107 to +1), and LIF promoter regions (-9032 to -8403). VEGF promoter activity was abolished by mutation of the PPRE motif. Treatment with 24-MCF inhibited expression of VEGF and inhibited the Akt/mTOR pathway. Treatment with 24-MCF also decreased VEGF secretion in MCF7 cells and PMA-stimulated tube formation in HUVECs. Our findings suggest that 24-MCF induces PPAR-γ2-mediated regulation of anti-angiogenesis via PPRE motifs in VEGF, HoxA7, and LIF promoters or upstream regions. Furthermore, 24-MCF treatment inhibits angiogenesis by blocking VEGF secretion.


Author(s):  
Shurong Ren ◽  
Qizhen Yue ◽  
Qiubo Wang ◽  
Yanli Zhang ◽  
Bei Zhang

Background: Chronic liver damages from viral infection or alcohol abuse result in liver fibrosis, which is a key pathological event in many types of liver diseases. Discovering new anti-fibrosis agents may provide alternative solutions to manage chronic liver diseases. Methods: We first used CCl4 induced liver fibrosis animal model to evaluate the beneficial effects of Cryptotanshinone (CRY). We next explored target miRNAs regulated by CRY in hepatocytes using microarray. The target miRNA candidate was confirmed with realtime-PCR. We also elucidated the downstream target and pathway directly regulated by the miRNA using luciferase assay, western blotting and Epithelial–Mesenchymal Transition (EMT) markers quantification. Lastly, we confirmed CRY induced expression changes of the target genes in vivo. Results: CRY oral administration markedly alleviated the liver injury caused by CCl4. miRNAs expression profiling and realtime-PCR validation revealed miR-539-3p was directly induced by CRY around 4 folds. The induction of miR-539-3p suppressed SMO expression and antagonized Hedgehog (Hh) pathway. Independently CRY treatment suppressed SMO and inhibited EMT process in hepatocytes. The CRY induced expression changes of both miR-539-3p (~ 2 folds increase) and SMO (~ 60% decrease) in livers were validated in animal model. Conclusion: Our study supported CRY could inhibit liver fibrosis by targeting Hh pathway during EMT. CRY could be used as anti-fibrosis agent candidate for managing chronic liver damages.


Oncogene ◽  
2021 ◽  
Vol 40 (13) ◽  
pp. 2355-2366
Author(s):  
Laura C. A. Galbraith ◽  
Ernest Mui ◽  
Colin Nixon ◽  
Ann Hedley ◽  
David Strachan ◽  
...  

AbstractPeroxisome Proliferator-Activated Receptor Gamma (PPARG) is one of the three members of the PPAR family of transcription factors. Besides its roles in adipocyte differentiation and lipid metabolism, we recently demonstrated an association between PPARG and metastasis in prostate cancer. In this study a functional effect of PPARG on AKT serine/threonine kinase 3 (AKT3), which ultimately results in a more aggressive disease phenotype was identified. AKT3 has previously been shown to regulate PPARG co-activator 1 alpha (PGC1α) localisation and function through its action on chromosome maintenance region 1 (CRM1). AKT3 promotes PGC1α localisation to the nucleus through its inhibitory effects on CRM1, a known nuclear export protein. Collectively our results demonstrate how PPARG over-expression drives an increase in AKT3 levels, which in turn has the downstream effect of increasing PGC1α localisation within the nucleus, driving mitochondrial biogenesis. Furthermore, this increase in mitochondrial mass provides higher energetic output in the form of elevated ATP levels which may fuel the progression of the tumour cell through epithelial to mesenchymal transition (EMT) and ultimately metastasis.


2015 ◽  
Vol 2015 ◽  
pp. 1-8 ◽  
Author(s):  
Lukasz Markiewicz ◽  
Dariusz Pytel ◽  
Bartosz Mucha ◽  
Katarzyna Szymanek ◽  
Jerzy Szaflik ◽  
...  

The aim of presented work was to analyze the impact of particular polymorphic changes in the promoter regions of the -1607 1G/2GMMP1, -1562 C/TMMP9, -82 A/GMMP12, -511 C/TIL-1β, and 372 T/CTIMP1genes on their expression level in POAG patients. Blood and aqueous humor samples acquired from 50 patients with POAG and 50 control subjects were used for QPCR and protein levels analysis by ELISA.In vivopromoter activity assays were carried on HTM cells using dual luciferase assay. All studied subjects underwent ophthalmic examination, including BCVA, intraocular pressure, slit-lamp examination, gonioscopy, HRT, and OCT scans. Patients with POAG are characterized by an increased mRNA expression ofMMP1,MMP9,MMP12, andIL-1βgenes as compared to the control group (P<0.001). Aqueous humor acquired from patients with POAG displayed increased protein expression of MMP1, MMP9, MMP12, and IL-1βcompared to the control group (P<0.001). Allele -1607 1G ofMMP1gene possesses only 42,91% of the -1607 2G allele transcriptional activity and allele -1562 C ofMMP9gene possesses only 21,86% of the -1562 T allele. Increased expression levels of metalloproteinases can be considered as a risk factor for the development of POAG.


1986 ◽  
Vol 6 (7) ◽  
pp. 2287-2297
Author(s):  
R Cohen ◽  
J P Holland ◽  
T Yokoi ◽  
M J Holland

There are two yeast enolase genes, designated ENO1 and ENO2, which are expressed differentially in vegetative cells grown on glucose and in cells grown on gluconeogenic carbon sources. ENO2 is induced more than 20-fold in cells grown on glucose, whereas ENO1 expression is similar in cells grown on glucose and in cells grown on gluconeogenic carbon sources. Sequences within the 5' flanking region of ENO2 which are required for glucose-dependent induction were identified by deletion mapping analysis. These studies were carried out by using a fused gene containing the ENO2 5' flanking sequences and the ENO1 coding sequences. This fused gene undergoes glucose-dependent induction and is expressed at the same level as the resident ENO2 gene in cells grown on glucose or gluconeogenic carbon sources. Expression of fused genes containing deletion mutations within the ENO2 5' flanking region was monitored after integration at the ENO1 locus of a strain carrying a deletion of the resident ENO1 coding sequences. This analysis showed that there are two upstream activation sites located immediately upstream and downstream from a position 461 base pairs upstream from the transcriptional initiation site. Either one of these upstream activation sites is sufficient for glucose-dependent induction and normal gene expression in the presence of gluconeogenic carbon sources. Deletion of both regulatory regions results in a complete loss of gene expression. The regulatory regions function normally in both orientations relative to the coding sequences. Mutant fused genes containing small deletions within the regulatory regions were constructed; these genes were expressed normally in gluconeogenic carbon sources but were not induced in the presence of glucose. Based on this analysis, ENO2 contains a cis-acting regulatory region which is required for gene expression and mediates glucose-dependent induction of gene expression.


2020 ◽  
Author(s):  
Yibing Li ◽  
Jianing Huo ◽  
Junjian He ◽  
Haining Ma ◽  
Xiaoxin Ma

Abstract Background: Emerging evidence shows that abnormal expression of long non-coding RNA is involved in the occurrence and development of various tumors. LncRNA MONC is abnormally expressed in head and neck squamous cell carcinoma (HNSCC), lung cancer, colorectal cancer, and acute megakaryocytic leukemia, but the biological function and potential regulatory mechanism of MONC in endometrial cancer stem cells (ECSCs) and endometrial cancer cells (ECCs) have not been studied. In this study, we aimed to explore the tumor suppressive effect and mechanism of MONC in regulating ECSCs and ECCs. Methods: The expression of genes was detected by quantitative reverse transcription polymerase chain reaction (qRT-PCR). The expression of proteins was detected by Western blot. The interplay of LncRNA-miRNA-mRNA was verified using the luciferase assay. The growth rate of ECSC spheroids was detected by sphere formation assay. Cell proliferation was detected by CCK-8 assay. The cell invasion was detected by transwell invasion assay. Cell cycle was detected by Cell cycle analysis.Cell apoptosis was detected by the Annexin V-fluorescein isothiocyanate (FITC)/propidium iodide (PI) double-staining assay. Animal study was conducted to evaluate the effect of MONC combined with miR-636 on tumor growth in vivo. Results: Low MONC expression in endometrial carcinoma (EC), which directly inhibits the malignant biological behavior of ECSCs and ECCs by directly inhibiting miR-636. Simultaneously, miR-636 may indirectly reduce the expression of MONC. Down-regulation of miR-636 may promote GLCE expression by targeting the 3'-untranslated region (UTR) of the downstream gene GLCE, thereby inhibiting the progression of ECSCs. MONC combined with miR-636 inhibited the Notch signaling pathway and tumor epithelial-to-mesenchymal transition (EMT) process. In addition, we verified the tumor suppressive effect of MONC in nude mice, miR-636 can rescue the tumor suppressive effect of overexpressing MONC, and this effect is more obvious in ECSC. Conclusion: MONC inhibits the malignant phenotypes of ECSCs and ECCs by regulating the miR-636/GLCE axis. The MONC/miR-636/GLCE axis may provide novel treatment avenues for human EC.


2021 ◽  
Vol 2021 ◽  
pp. 1-17
Author(s):  
Shoujun Bai ◽  
Xiaoyan Xiong ◽  
Bo Tang ◽  
Tingting Ji ◽  
Xiaoying Li ◽  
...  

Diabetic nephropathy (DN) is the leading cause of end-stage renal disease. The association between epithelial-mesenchymal transition (EMT) and fibrosis is quite ascertained, but its link to eventual tubule dysfunction is missing. Here, we show that human microRNA- (hsa-miR-) 199b-3p protects renal tubules from diabetic-induced injury by repressing KDM6A, a histone lysine demethylase regulating E-cadherin expression. Lower E-cadherin expression is related to a higher level of KDM6A, while E-cadherin is promoted upon treatment with the KDM6A inhibitor GSK-J4 in both high glucose- (HG-) induced HK2 cells and the kidneys from streptozotocin- (STZ-) induced type 1 diabetic mice. However, overexpression or RNA silencing of E-cadherin fails to alter KDM6A expression. We also show that the upregulation of KDM6A is associated with the increased methylation level of the E-cadherin promoter. Then, the target prediction results and a dual-luciferase assay show that hsa-miR-199b-3p is a new miRNA that targets KDM6A. Overexpression of hsa-miR-199b-3p increases E-cadherin expression and prevents EMT through repressing KDM6A expression in HG-induced HK2 cells. In contrast, inhibitor-induced hsa-miR-199b-3p knockdown has opposite effects, as it decreases E-cadherin level and worsens EMT, accompanied by increased levels of KDM6A. Besides, Mir199b-knockout mice without mmu-miR-119b-3p expression exhibit more renal tubule dysfunction and more serious kidney tissue damage upon treatment with STZ. These results demonstrate that hsa-miR-199b-3p improves E-cadherin expression and prevents the progression of DN through targeting KDM6A. miR-199b-3p could be a future biomarker or target for the diagnosis or treatment of DN.


2021 ◽  
Vol 14 (1) ◽  
Author(s):  
Jin Wang ◽  
Lingxia Liu

Abstract Background Ovarian cancer (OC), a kind of gynecological cancer, is characterized by high mortality rate, with microRNAs (miRNAs) playing essential roles in it. However, the clinical significance of miRNAs and their molecular mechanisms in OC are mostly unknown. Methods miR-149-3p expression was predicted through Gene Expression Omnibus (GEO) data in OC and confirmed by q-PCR in various OC cells and tissues from patients with different clinical characteristics. Moreover, its roles in terms of proliferation, migration and invasion were measured by CCK-8, colony formation, wound healing and transwell assays in OC cells including cisplatin-resistant and cisplatin-sensitive cells. And its effect on epithelial-mesenchymal transition was also assessed through detecting related protein expression. Additionally, its potential targets were verified by dual luciferase assay and Ago-RIP assay. Finally, its oncogenic functions were explored in vivo. Results In data from GSE79943, GSE131790, and TCGA, miR-149-3p was found to be highly expressed in OC tissues and associated with poor survival. In metastasis and chemoresistant tissues and cisplatin-resistant OC cells, its high expression was confirmed. In terms of tumorigenic effects, miR-149-3p knockdown in cisplatin-resistant OC cells inhibited its cisplatin resistance and other malignant phenotypes, while miR-149-3p overexpression in cisplatin-resistant OC cells led to contrary results. Mechanistically, miR-149-3p targeted 3’UTR of CDKN1A and TIMP2 to function as an oncogenic miRNA. Conclusion In brief, miR-149-3p promoted cisplatin resistance and EMT in OC by downregulating CDKN1A and TIMP2, which might provide a potential therapeutic target for OC treatment.


2020 ◽  
Vol 11 (10) ◽  
Author(s):  
Bei Li ◽  
Ang Li ◽  
Zhen You ◽  
Jingchang Xu ◽  
Sha Zhu

Abstract Enhanced SNHG1 (small nucleolar RNA host gene 1) expression has been found to play a critical role in the initiation and progression of hepatocellular carcinoma (HCC) with its detailed mechanism largely unknown. In this study, we show that SNHG1 promotes the HCC progression through epigenetically silencing CDKN1A and CDKN2B in the nucleus, and competing with CDK4 mRNA for binding miR-140-5p in the cytoplasm. Using bioinformatics analyses, we found hepatocarcinogenesis is particularly associated with dysregulated expression of SNHG1 and activation of the cell cycle pathway. SNHG1 was upregulated in HCC tissues and cells, and its knockdown significantly inhibited HCC cell cycle, growth, metastasis, and epithelial–mesenchymal transition (EMT) both in vitro and in vivo. Chromatin immunoprecipitation and RNA immunoprecipitation assays demonstrate that SNHG1 inhibit the transcription of CDKN1A and CDKN2B through enhancing EZH2 mediated-H3K27me3 in the promoter of CDKN1A and CDKN2B, thus resulting in the de-repression of the cell cycle. Dual-luciferase assay and RNA pulldown revealed that SNHG1 promotes the expression of CDK4 by competitively binding to miR-140-5p. In conclusion, we propose that SNHG1 formed a regulatory network to confer an oncogenic function in HCC and SNHG1 may serve as a potential target for HCC diagnosis and treatment.


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