scholarly journals Role of Sp1 transcription factor in the pathogenesis of diabetic retinopathy

2012 ◽  
Vol 90 ◽  
pp. 0-0
Author(s):  
K DONOVAN ◽  
O ALEKSEEV ◽  
W CHO ◽  
J AZIZKHAN-CLIFFORD
Keyword(s):  
Transcription Factor ◽  
Diabetic Retinopathy ◽  
Sp1 Transcription Factor

scholarly journals Hsa_circ_0026628 promotes the development of colorectal cancer by targeting SP1 to activate the Wnt/β-catenin pathway

2021 ◽  
Vol 12 (9) ◽  
Author(s):  
Xuexiu Zhang ◽  
Jianning Yao ◽  
Haoling Shi ◽  
Bing Gao ◽  
Haining Zhou ◽  
...  
Keyword(s):  
Colorectal Cancer ◽  
Transcription Factor ◽  
Circular Rna ◽  
Luciferase Reporter ◽  
Circular Rnas ◽  
Transcriptional Level ◽  
Sp1 Transcription Factor ◽  
Reporter Assays ◽  
Sphere Formation

AbstractCircular RNAs (circRNAs) have been reported to play crucial roles in the progression of various cancers, including colorectal cancer (CRC). SP1 (Sp1 transcription factor) is a well-recognized oncogene in CRC and is deemed to trigger the Wnt/β-catenin pathway. The present study was designed to investigate the role of circRNAs which shared the same pre-mRNA with SP1 in CRC cells. We identified that hsa_circ_0026628 (circ_0026628), a circular RNA that originated from SP1 pre-mRNA, was upregulated in CRC cells. Sanger sequencing and agarose gel electrophoresis verified the circular characteristic of circ_0026628. Functional assays including CCK-8, colony formation, transwell, immunofluorescence staining, and sphere formation assay revealed the function of circ_0026628. RNA pull-down and mass spectrometry disclosed the proteins interacting with circ_0026628. Mechanistic assays including RIP, RNA pull-down, CoIP, ChIP, and luciferase reporter assays demonstrated the interplays between molecules. The results depicted that circ_0026628 functioned as a contributor to CRC cell proliferation, migration, EMT, and stemness. Mechanistically, circ_0026628 served as the endogenous sponge of miR-346 and FUS to elevate SP1 expression at the post-transcriptional level, thus strengthening the interaction between SP1 and β-catenin to activate the Wnt/β-catenin pathway. In turn, the downstream gene of Wnt/β-catenin signaling, SOX2 (SRY-box transcription factor 2), transcriptionally activated SP1 and therefore boosted circ_0026628 level. On the whole, SOX2-induced circ_0026628 sponged miR-346 and recruited FUS protein to augment SP1, triggering the downstream Wnt/β-catenin pathway to facilitate CRC progression.

A critical role of Sp1 transcription factor in regulating gene expression in response to insulin and other hormones

Life Sciences ◽  
2008 ◽  
Vol 83 (9-10) ◽  
pp. 305-312 ◽  
Author(s):  
Solomon S. Solomon ◽  
Gipsy Majumdar ◽  
Antonio Martinez-Hernandez ◽  
Rajendra Raghow
Keyword(s):  
Gene Expression ◽  
Transcription Factor ◽  
Critical Role ◽  
Sp1 Transcription Factor

A critical role of Sp1 transcription factor in regulating the human Ki-67 gene expression

Tumor Biology ◽  
2010 ◽  
Vol 32 (2) ◽  
pp. 273-283 ◽  
Author(s):  
Hui Tian ◽  
Guo-Wei Qian ◽  
Wang Li ◽  
Fei-Fei Chen ◽  
Jie-Hui Di ◽  
...  
Keyword(s):  
Gene Expression ◽  
Transcription Factor ◽  
Critical Role ◽  
Ki 67 ◽  
Sp1 Transcription Factor

scholarly journals Silencing of Transcription Factor Sp1 Promotes SN1 Transporter Regulation by Ammonia in Mouse Cortical Astrocytes

2019 ◽  
Vol 20 (2) ◽  
pp. 234 ◽  
Author(s):  
Katarzyna Dąbrowska ◽  
Magdalena Zielińska
Keyword(s):  
Transcription Factor ◽  
Cellular Localization ◽  
Sp1 Transcription Factor ◽  
Kinase C ◽  
Cultured Astrocytes ◽  
Pkc Isoforms ◽  
Specificity Protein ◽  
Glutamine Uptake

The involvement of the astrocytic SN1 (SNAT3) transporter in ammonia-induced l-glutamine retention was recently documented in mouse-cultured astrocytes. Here we investigated the involvement of specificity protein 1 (Sp1) transcription factor in SN1 regulation in ammonium chloride (“ammonia”)-treated astrocytes. Sp1 expression and its cellular localization were determined using real-time qPCR, Western blot, and confocal microscopy. Sp1 binding to Snat3 promoter was analyzed by chromatin immunoprecipitation. The role of Sp1 in SN1 expression and SN1-mediated [3H]glutamine uptake in ammonia-treated astrocytes was verified using siRNA and mithramycin A. The involvement of protein kinase C (PKC) isoforms in Sp1 level/phosphorylation status was verified using siRNA technology. Sp1 translocation to the nuclei and its enhanced binding to the Snat3 promoter, along with Sp1 dependence of system N-mediated [3H]glutamine uptake, were observed in astrocytes upon ammonia exposure. Ammonia decreased the level of phosphorylated Sp1, and the effect was reinforced by long-term incubation with PKC modulator, phorbol 12-myristate 13-acetate, which is a treatment likely to dephosphorylate Sp1. Furthermore, silencing of the PKCδ isoform appears to enhance the ammonia effect on the Sp1 level. Collectively, the results demonstrate the regulatory role of Sp1 in regulation of SN1 expression and activity in ammonia-treated astrocytes and implicate altered Sp1 phosphorylation status in this capacity.

scholarly journals Understanding the Role of the Transcription Factor Sp1 in Ovarian Cancer: from Theory to Practice

2020 ◽  
Vol 21 (3) ◽  
pp. 1153 ◽  
Author(s):  
Vellingiri ◽  
Iyer ◽  
Devi Subramaniam ◽  
Jayaramayya ◽  
Siama ◽  
...  
Keyword(s):  
Ovarian Cancer ◽  
Transcription Factor ◽  
Cancer Cells ◽  
Cellular Reprogramming ◽  
Over Expression ◽  
Sp1 Transcription Factor ◽  
Cellular Genes ◽  
Risk Of Mortality ◽  
Specificity Protein

Ovarian cancer (OC) is one of the deadliest cancers among women contributing to high risk of mortality, mainly owing to delayed detection. There is no specific biomarker for its detection in early stages. However, recent findings show that over-expression of specificity protein 1 (Sp1) is involved in many OC cases. The ubiquitous transcription of Sp1 apparently mediates the maintenance of normal and cancerous biological processes such as cell growth, differentiation, angiogenesis, apoptosis, cellular reprogramming and tumorigenesis. Sp1 exerts its effects on cellular genes containing putative GC–rich Sp1–binding site in their promoters. A better understanding of the mechanisms underlying Sp1 transcription factor (TF) regulation and functions in OC tumorigenesis could help identify novel prognostic markers, to target cancer stem cells (CSCs) by following cellular reprogramming and enable the development of novel therapies for future generations. In this review, we address the structure, function, and biology of Sp1 in normal and cancer cells, underpinning the involvement of Sp1 in OC tumorigenesis. In addition, we have highlighted the influence of Sp1 TF in cellular reprogramming of iPSCs and how it plays a role in controlling CSCs. This review highlights the drugs targeting Sp1 and their action on cancer cells. In conclusion, we predict that research in this direction will be highly beneficial for OC treatment, and chemotherapeutic drugs targeting Sp1 will emerge as a promising therapy for OC.

scholarly journals Down‐regulation of the Sp1 transcription factor by an increase of microRNA-4497 in human placenta is associated with early recurrent miscarriage

2021 ◽  
Vol 19 (1) ◽  
Author(s):  
Huaiyun Tang ◽  
Linqing Pan ◽  
Yun Xiong ◽  
Leilei Wang ◽  
Yugui Cui ◽  
...  
Keyword(s):  
Transcription Factor ◽  
Bioinformatics Analysis ◽  
Recurrent Miscarriage ◽  
Luciferase Reporter ◽  
Pathophysiological Mechanism ◽  
Placental Villus ◽  
Target Mrnas ◽  
Sp1 Transcription Factor ◽  
Normal Controls

Abstract Background The pathophysiological mechanism of recurrent miscarriage (RM) is unclear. The goals of this study were to determine the role of microRNA-4497 overexpression in placental villus tissues in early RM; To identify the potential target mRNAs of miRNA-4497; And to investigate the microRNA-4497-mediated regulatory mechanisms in placental trophoblasts. Methods Bioinformatics analysis was performed to identify the candidate target genes of miRNA-4497. The protein expression of Sp1 transcription factor (SP1), chemokine (C-X-C motif) receptor 5 (CXCR5) and bone morphogenetic protein 8a (BMP8A) were determined in the villus tissues of the RM and normal groups by Western blotting and immunohistochemistry. Cultured 293T cells were co-transfected with the miRNA-4497 agomir or luciferase reporter vectors containing the wild-type or mutant 3’-UTRs of the target mRNAs to verify the regulatory role of miRNA-4497. Results Bioinformatics analysis suggested that SP1, CXCR5 and BMP8A mRNAs are potential targets of miRNA-4497. The expression of SP1, CXCR5 and BMP8A proteins in the chorionic villus tissues of RM placentas were significantly decreased compared to those in the normal controls. Moreover, SP1 protein levels were inversely correlated with the levels of miRNA-4497 in the placentas of RM patients and normal controls. The expression of SP1 mRNA and protein were down-regulated in HTR-8/SVneo cells after forced overexpression of the miRNA-4497 agomir. The results of the co-transfection assay showed that mutation of the miRNA-4497-binding sites in the 3’-untranslated region (3’-UTR) of SP1 led to a recovery of luciferase activity upon overexpression of miRNA-4497, suggesting that SP1 could be a direct target of miRNA-4497. Conclusions An increased miRNA-4497 level in the placental villus tissues associated with recurrent miscarriage may down-regulate SP1 expression. The negative regulation of SP1 by miRNA-4497 may potentially contribute to the pathogenesis of recurrent miscarriage through promotion of trophoblast apoptosis. These findings provide novel information on the regulation of placental trophoblast apoptosis, and could be useful for the development of new therapeutic strategies for better management of recurrent miscarriage.

The role of transcription factor Egr‐1 in IL‐1 up‐regulation of tubular CD44 expression

Nephrology ◽  
2000 ◽  
Vol 5 (3) ◽  
pp. A92-A92
Author(s):  
Takazoe K ◽  
Foti R ◽  
Hurst La ◽  
Atkins Rc ◽  
Nikolic‐Paterson DJ.
Keyword(s):  
Transcription Factor ◽  
Cd44 Expression
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