scholarly journals β-catenin/LEF-1 Transcription Complex is Responsible for the Transcriptional Activation of LINC01278

Author(s):  
Shaojian Lin ◽  
Weiwei Zhang ◽  
Ziwen Shi ◽  
Langping Tan ◽  
Yue Zhu ◽  
...  

Abstract Background: Our previous study shows that LINC01278 inhibits the development of papillary thyroid carcinoma (PTC) by regulating miR-376c-3p/DNM3 axis. However, the regulation mechanism of LINC01278 expression in PTC cells is still unclear. Methods: The luciferase reporter and ChIP assays were used to confirme the binding of LEF-1 to the putative promoter site of LINC01278. The RNA immunoprecipitation was used the enrichment of LINC01278 in β-catenin protein. Western blot was used to detected the expression of target proteins. Results: Firstly, the online PROMO algorithm determined a putative LEF-1 binding site on LINC01278 promoter. Then, the luciferase reporter and ChIP assays confirmed the binding of LEF-1 to the putative promoter site of LINC01278. Furthermore, the overexpression of β-catenin increased the binding of LEF-1 to the LINC01278 promoter, and the knockdown or overexpression of LEF-1 or β-catenin can affect the expression level of LINC01278. In addition, RNA immunoprecipitation showed that LINC01278 was enriched in β-catenin protein. RNA pulldown and western blot also confirmed that LINC01278 precipitated β-catenin in TPC-1 and BCPAP cells. Furthermore, the knockdown or overexpression of LINC01278 significantly affected the expression of β-catenin and targets of Wnt/β-catenin signaling pathway (CCND2, CyclinD1, MYC, and SOX4). Conclusion: In summary, we found the transcriptional activation of LINC01278 by the β-catenin/LEF-1 transcription factor, and the negative feedback regulation of LINC01278 on Wnt/β-catenin signaling pathway activation.

2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Shaojian Lin ◽  
Weiwei Zhang ◽  
Ziwen Shi ◽  
Langping Tan ◽  
Yue Zhu ◽  
...  

Abstract Background Our previous study shows that LINC01278 inhibits the malignant proliferation and invasion of papillary thyroid carcinoma (PTC) cells by regulating the miR-376c-3p/DNM3 axis. However, the regulation mechanism of LINC01278 expression in PTC cells is still unclear. Methods The luciferase reporter and ChIP assays were used to confirm the binding of LEF-1 to the putative promoter site of LINC01278 gene. The RNA immunoprecipitation and RNA pulldown were used to determine the enrichment of LINC01278 in β-catenin protein. The proteasome inhibitors (MG132) was used for detecting the β-catenin ubiquitination-proteasome degradation. Wnt/β-catenin specific agonists (LiCI), inhibitors (WiKI4) and TOP/FOP-flash reporter assay were used for detecting the activation of Wnt/β-catenin signal. Western blot was used to detected the expression of target proteins. Results The online PROMO algorithm determines a putative LEF-1 binding site on LINC01278 promoter, the LEF-1 binds to the putative promoter site of LINC01278 gene, and β-catenin enhances the binding of LEF-1 to the LINC01278 gene promoter. Furthermore, LINC01278 negatively regulated the protein accumulation of β-catenin in the cytoplasm, into nucleus, and ultimately inhibited the transcription of downstream target genes activated by Wnt/β-catenin signal. The results of RNA immunoprecipitation and RNA pulldown proved the direct binding of LINC01278 to β-catenin protein. In addition, the combination of LINC01278 and β-catenin promotes the β-catenin ubiquitination-proteasome degradation. Conclusion In summary, we found the transcriptional activation of LINC01278 by the β-catenin/LEF-1 transcription factor, and the negative feedback regulation of LINC01278 onβ-catenin signal.


Author(s):  
Zeyin Rong ◽  
Zai Luo ◽  
Zhongmao Fu ◽  
Pengshan Zhang ◽  
Tengfei Li ◽  
...  

Abstract Background Colorectal cancer (CRC) is one of the most frequent malignancy and a leading cause of cancer-related deaths. Therefore, further researches are required to identify novel and more effective diagnoses and to identify molecular targets in treatment of CRC. Methods C2CD4A expression in CRC tissues and cell lines was detected by qRT-PCR and western blot. The biological functions of C2CD4A were performed both in vitro and in vivo. Western blot, cDNA array, IP-MS, Co-immunoprecipitation assay, and Ubiquitination assay were used to analyze the interaction between C2CD4A and p53. Bioinformatics analysis, FISH, RNA sequencing, luciferase reporter assay, RNA immunoprecipitation, RNA pull-down and rescue experiments, were deployed to detect upstream regulation mechanism of C2CD4A. Results C2CD4A was elevated in CRC tissues compared with adjacent normal colorectal tissues. C2CD4A knockdown significantly promoted cell apoptosis and with inhibited proliferation in vitro, and tumorigenicity in vivo, whereas C2CD4A overexpression led to opposite effects. Moreover, circSLC6A6 was upregulated and shown to positively regulate C2CD4A expression via sponging miR-1265. Fundamentally, C2CD4A inhibited p53 signaling pathway through interacting with p53 and increasing its ubiquitination and degradation. Conclusion Our results identified that circSLC6A6/miR-1265/C2CD4A axis, which was involved in CRC via the p53 signaling pathway, may serve as a therapeutic target for CRC.


2021 ◽  
Author(s):  
Zeyin Rong ◽  
Zai Luo ◽  
Zhongmao Fu ◽  
Pengshan Zhang ◽  
Tengfei Li ◽  
...  

Abstract Background: Colorectal cancer (CRC) ranks as the third most frequently diagnosed cancer and is a leading cause of cancer-related deaths. Therefore, further researches were required to identify novel and more effective diagnoses and to identify molecular targets in treatment of CRC.Methods: CRC fresh frozen tissues and cell lines were used to detect C2CD4A expression by qRT-PCR and western blotting. The biological functions of C2CD4A were performed in vitro and in vivo. Western blotting, cDNA array, IP-MS, Co-IP, and Ubiquitination assay were used to analyze the interaction between C2CD4A and p53. Bioinformatics analysis, FISH, RNA sequencing, luciferase reporter assay, RNA immunoprecipitation, RNA pull-down and rescue experiments, were deployed to detect upstream regulation mechanism of C2CD4A.Results: C2CD4A was aberrantly upregulated in CRC tissues compared with adjacent normal colorectal tissues. C2CD4A knockdown significantly promoted cell apoptosis and with inhibited proliferation in vitro, and tumorigenicity in vivo, whereas C2CD4A overexpression had displayed an opposite effect. Moreover, circSLC6A6 was upregulated and positively associated with C2CD4A expression in CRC tissues. C2CD4A was positively regulated by circSLC6A6 via sponging miR-1265. Fundamentally, C2CD4A inhibited P53 signaling pathway through interacting with P53 and increasing its ubiquitination and degradation.Conclusion: Our results identified that circSLC6A6/miR-1265/C2CD4A axis, which was involved in CRC via the P53 signaling pathway, could be as a therapeutic target for CRC.


2021 ◽  
Vol 2021 ◽  
pp. 1-11
Author(s):  
Xiangwei Lv ◽  
Pan Lu ◽  
Yisen Hu ◽  
Tongtong Xu

Purpose. Studies have found that microRNAs (miRNAs) are closely associated with atrial fibrillation, but their specific mechanism remains unclear. The purpose of this experiment is to explore the function of miR-29b-3p in regulating atrial remodeling by targeting PDGF-B signaling pathway and thereby also explore the potential mechanisms. Methods. We randomly divided twenty-four rats into four groups. Caudal intravenous injections of angiotensin-II (Ang-II) were administered to establish atrial fibrosis models. Expressions of miR-29b-3p and PDGF-B were then tested via RT-PCR, western blot, and immunohistochemistry. Binding sites were then analyzed via the bioinformatics online software TargetScan and verified by Luciferase Reporter. We used Masson staining to detect the degree of atrial fibrosis, while immunofluorescence and western blot were used to detect the expressions of Collagen-I and a-SMA. We used immunohistochemistry and western blot to detect the expression of connexin 43 (Cx43). Results. In comparison with the Ang-II group, miR-29b-3p was seen to lower the degree of atrial fibrosis, decrease the expression of fibrosis markers such as Collagen-I and a-SMA, and increase the protein expression of Cx43. MiR-29b-3p can lower the expression of PDGF-B, while the Luciferase Reporter showed that PDGF-B is the verified target gene of miR-29b-3p. Conclusions. MiR-29b-3p was able to reduce atrial structural and electrical remodeling in the study’s rat fibrosis model. This biological function may be expressed through the targeted regulation of the PDGF-B signaling pathway.


2018 ◽  
Vol 18 (6) ◽  
pp. 484-493 ◽  
Author(s):  
Xiang Cheng ◽  
Jianying Li ◽  
Deliang Guo

Lipid metabolism reprogramming emerges as a new hallmark of malignancies. Sterol regulatory element-binding proteins (SREBPs), which are central players in lipid metabolism, are endoplasmic reticulum (ER)-bound transcription factors that control the expression of genes important for lipid synthesis and uptake. Their transcriptional activation requires binding to SREBP cleavageactivating protein (SCAP) to translocate their inactive precursors from the ER to the Golgi to undergo cleavage and subsequent nucleus translocation of their NH2-terminal forms. Recent studies have revealed that SREBPs are markedly upregulated in human cancers, providing the mechanistic link between lipid metabolism alterations and malignancies. Pharmacological or genetic inhibition of SCAP or SREBPs significantly suppresses tumor growth in various cancer models, demonstrating that SCAP/SREBPs could serve as promising metabolic targets for cancer therapy. In this review, we will summarize recent progress in our understanding of the underlying molecular mechanisms regulating SCAP/SREBPs and lipid metabolism in malignancies, discuss new findings about SREBP trafficking, which requires SCAP N-glycosylation, and introduce a newly identified microRNA-29-mediated negative feedback regulation of the SCAP/SREBP pathway. Moreover, we will review recently developed inhibitors targeting the SCAP/SREBP pathway for cancer treatment.


2020 ◽  
Vol 71 (20) ◽  
pp. 6211-6225
Author(s):  
Peter G H de Rooij ◽  
Giorgio Perrella ◽  
Eirini Kaiserli ◽  
Martijn van Zanten

Abstract Plants tightly control gene transcription to adapt to environmental conditions and steer growth and development. Different types of epigenetic modifications are instrumental in these processes. In recent years, an important role for the chromatin-modifying RPD3/HDA1 class I HDAC HISTONE DEACETYLASE 9 (HDA9) emerged in the regulation of a multitude of plant traits and responses. HDACs are widely considered transcriptional repressors and are typically part of multiprotein complexes containing co-repressors, DNA, and histone-binding proteins. By catalyzing the removal of acetyl groups from lysine residues of histone protein tails, HDA9 negatively controls gene expression in many cases, in concert with interacting proteins such as POWERDRESS (PWR), HIGH EXPRESSION OF OSMOTICALLY RESPONSIVE GENES 15 (HOS15), WRKY53, ELONGATED HYPOCOTYL 5 (HY5), ABA INSENSITIVE 4 (ABI4), and EARLY FLOWERING 3 (ELF3). However, HDA9 activity has also been directly linked to transcriptional activation. In addition, following the recent breakthrough discovery of mutual negative feedback regulation between HDA9 and its interacting WRKY-domain transcription factor WRKY53, swift progress in gaining understanding of the biology of HDA9 is expected. In this review, we summarize knowledge on this intriguing versatile—and long under-rated—protein and propose novel leads to further unravel HDA9-governed molecular networks underlying plant development and environmental biology.


Molecules ◽  
2018 ◽  
Vol 23 (8) ◽  
pp. 2047 ◽  
Author(s):  
Lijun Ji ◽  
Mingfei Wu ◽  
Zeng Li

This study aimed to investigate the effect of Ru (Rut) on angiogenesis, and the underlying regulation mechanism of signal transduction. 3-(4,5-dimethyl-2-thiazolyl)-2,5-diphenyl-2H-tetrazolium bromide (MTT) assay, adhesion inhibition experiment, migration inhibition experiment, and chick embryo chorioallantoic membrane (CAM) assays were performed on models of angiogenesis. The potential targets of rutaecarpine (Ru) were reverse screened with Discovery Studio 2017. The interaction between the compound and target were detected by surface plasmon resonance (SPR), enzyme-activity experiment, and Western blot assay. The obtained results confirmed that Ru exhibited modest inhibitory activity against human umbilical vein endothelial cells (HUVECs) (IC50 =16.54 ± 2.4 μM) and remarkable inhibitive effect against the migration and adhesion of HUVECs, as well as significant anti-angiogenesis activities in the CAM assay. The possible targets of vascular endothelial growth factor receptor 2 (VEGFR2) were identified by computer-aided simulation. Results showed a good binding relationship between the ligand and target through molecular docking, and this relationship was confirmed by SPR analysis. Furthermore, enzyme-activity experiment and western blot assay showed that Ru remarkably inhibited the activity of VEGFR2 and blocked the VEGFR2-mediated Akt/ (mTOR)/p70s6k signaling pathway in vitro. Ru can be a potential drug candidate for cancer prevention and cancer therapy.


2018 ◽  
Vol 2018 ◽  
pp. 1-12 ◽  
Author(s):  
Meixiu Zhang ◽  
Cuizhe Wang ◽  
Jinxiu Wu ◽  
Xiaodan Ha ◽  
Yuchun Deng ◽  
...  

Objective. To investigate the role and possible molecular mechanism of Krüppel-like factor 7 (KLF7) in the TLR4/NF-κB/IL-6 inflammatory signaling pathway activated by free fatty acids (FFA). Methods. The mRNA and protein expression levels of KLF7 and the factors of TLR4/NF-κB/IL-6 inflammatory signal pathways were detected by qRT-PCR and Western blotting after cell culture with different concentrations of palmitic acid (PA). The expression of KLF7 or TLR4 in adipocytes was upregulated or downregulated; after that, the mRNA and protein expression levels of these key factors were detected. KLF7 expression was downregulated while PA stimulated adipocytes, and then the mRNA and protein expressions of KLF7/p65 and downstream inflammatory cytokine IL-6 were detected. The luciferase reporter assay was used to determine whether KLF7 had a transcriptional activation effect on IL-6. Results. (1) High concentration of PA can promote the expression of TLR4, KLF7, and IL-6 in adipocytes. (2) TLR4 positively regulates KLF7 expression in adipocytes. (3) KLF7 positively regulates IL-6 expression in adipocytes. (4) PA promotes IL-6 expression via KLF7 in adipocytes. (5) KLF7 has a transcriptional activation on IL-6. Conclusion. PA promotes the expression of the inflammatory cytokine IL-6 by activating the TLR4/KLF7/NF-κB inflammatory signaling pathway. In addition, KLF7 may directly bind to the IL-6 promoter region and thus activate IL-6.


2021 ◽  
Vol 12 ◽  
Author(s):  
Juan Duan ◽  
Xuantao Hu ◽  
Tao Li ◽  
Gen Wu ◽  
Pengcheng Dou ◽  
...  

Background: Aseptic loosening of prosthesis (ALP) is one of the most common long-term complications of knee and hip arthroplasty. Wear particle-induced osteoclastogenesis and subsequent periprosthetic osteolysis account for the morbidity of ALP. Here, we investigate the potential of cimifugin (CIM), a natural extract from Cimicifuga racemosa and Saposhnikovia divaricata, as a bone-protective drug in the treatment of ALP.Method: First, we performed cell viability and osteoclast formation assays to assess the effect of noncytotoxic CIM on osteoclast differentiation in vitro. Bone slice resorption and F-actin ring immunofluorescence assays were adopted to assess the effects of CIM on bone-resorption function. Then, quantitative real-time polymerase chain reaction (qRT–PCR) analysis was performed to further assess the repressive effects of CIM on osteoclastogenesis at the gene expression level. To elucidate the mechanisms underlying the above findings, Western blot and luciferase reporter gene assays were used to assess the regulatory effects of CIM on the NF-κB and MAPK signaling pathways. Moreover, a Ti particle-induced murine calvarial osteolysis model and subsequent histomorphometric analysis via micro-CT and immunohistochemical staining were used to elucidate the effect of CIM on periprosthetic osteolysis in vivo.Result: CIM dose-dependently inhibited both bone marrow-derived macrophage (BMM)- and RAW264.7 cell-derived osteoclastogenesis and bone resorption pit formation in vitro, which was further supported by the reduced expression of F-actin and osteoclast-specific genes. According to the Western blot analysis, inhibition of IκBα phosphorylation in the NF-κB signaling pathway, not the phosphorylation of MAPKs, was responsible for the suppressive effect of CIM on osteoclastogenesis. Animal experiments demonstrated that CIM alleviated Ti particle-induced bone erosion and osteoclast accumulation in murine calvaria.Conclusion: The current study suggested for the first time that CIM can inhibit RANKL-induced osetoclastogenesis by suppressing the NF-κB signaling pathway in vitro and prevent periprosthetic osteolysis in vivo. These findings suggest the potential of CIM as a therapeutic in ALP.


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