scholarly journals SENP1 promotes hypoxia-induced cancer stemness by HIF-1α deSUMOylation and SENP1/HIF-1α positive feedback loop

Gut ◽  
2017 ◽  
Vol 66 (12) ◽  
pp. 2149-2159 ◽  
Author(s):  
Chun-Ping Cui ◽  
Carmen Chak-Lui Wong ◽  
Alan Ka-Lun Kai ◽  
Daniel Wai-Hung Ho ◽  
Eunice Yuen-Ting Lau ◽  
...  
Keyword(s):  
Stem Cell ◽  
Positive Feedback ◽  
Feedback Loop ◽  
Mrna Level ◽  
Cancer Stemness ◽  
Positive Feedback Loop ◽  
Sumo Proteases ◽  
Immunocompromised Mice ◽  
Element Sequence

ObjectiveWe investigated the effect and mechanism of hypoxic microenvironment and hypoxia-inducible factors (HIFs) on hepatocellular carcinoma (HCC) cancer stemness.DesignHCC cancer stemness was analysed by self-renewal ability, chemoresistance, expression of stemness-related genes and cancer stem cell (CSC) marker-positive cell population. Specific small ubiquitin-like modifier (SUMO) proteases 1 (SENP1) mRNA level was examined with quantitative PCR in human paired HCCs. Immunoprecipitation was used to examine the binding of proteins and chromatin immunoprecipitation assay to detect the binding of HIFs with hypoxia response element sequence. In vivo characterisation was performed in immunocompromised mice and stem cell frequency was analysed.ResultsWe showed that hypoxia enhanced the stemness of HCC cells and hepatocarcinogenesis through enhancing HIF-1α deSUMOylation by SENP1 and increasing stabilisation and transcriptional activity of HIF-1α. Furthermore, we demonstrated that SENP1 is a direct target of HIF-1/2α and a previously unrecognised positive feedback loop exists between SENP1 and HIF-1α.ConclusionsTaken together, our findings suggest the significance of this positive feedback loop between HIF-1α and SENP1 in contributing to the increased cancer stemness in HCC and hepatocarcinogenesis under hypoxia. Drugs that specifically target SENP1 may offer a potential novel therapeutic approach for HCC.

scholarly journals CDK13 upregulation-induced formation of the positive feedback loop among circCDK13, miR-212-5p/miR-449a and E2F5 contributes to prostate carcinogenesis

2021 ◽  
Vol 40 (1) ◽  
Author(s):  
Jin-Chun Qi ◽  
Zhan Yang ◽  
Tao Lin ◽  
Long Ma ◽  
Ya-Xuan Wang ◽  
...  
Keyword(s):  
Cell Proliferation ◽  
Transcriptional Activation ◽  
Positive Feedback ◽  
Feedback Loop ◽  
Biological Effects ◽  
Therapeutic Benefit ◽  
Loss Of Function ◽  
Positive Feedback Loop

Abstract Background Both E2F transcription factor and cyclin-dependent kinases (CDKs), which increase or decrease E2F activity by phosphorylating E2F or its partner, are involved in the control of cell proliferation, and some circRNAs and miRNAs regulate the expression of E2F and CDKs. However, little is known about whether dysregulation among E2Fs, CDKs, circRNAs and miRNAs occurs in human PCa. Methods The expression levels of CDK13 in PCa tissues and different cell lines were determined by quantitative real-time PCR and Western blot analysis. In vitro and in vivo assays were preformed to explore the biological effects of CDK13 in PCa cells. Co-immunoprecipitation anlysis coupled with mass spectrometry was used to identify E2F5 interaction with CDK13. A CRISPR-Cas9 complex was used to activate endogenous CDK13 and circCDK13 expression. Furthermore, the mechanism of circCDK13 was investigated by using loss-of-function and gain-of-function assays in vitro and in vivo. Results Here we show that CDK13 is significantly upregulated in human PCa tissues. CDK13 depletion and overexpression in PCa cells decrease and increase, respectively, cell proliferation, and the pro-proliferation effect of CDK13 is strengthened by its interaction with E2F5. Mechanistically, transcriptional activation of endogenous CDK13, but not the forced expression of CDK13 by its expression vector, remarkably promotes E2F5 protein expression by facilitating circCDK13 formation. Further, the upregulation of E2F5 enhances CDK13 transcription and promotes circCDK13 biogenesis, which in turn sponges miR-212-5p/449a and thus relieves their repression of the E2F5 expression, subsequently leading to the upregulation of E2F5 expression and PCa cell proliferation. Conclusions These findings suggest that CDK13 upregulation-induced formation of the positive feedback loop among circCDK13, miR-212-5p/miR-449a and E2F5 is responsible for PCa development. Targeting this newly identified regulatory axis may provide therapeutic benefit against PCa progression and drug resistance.

scholarly journals Interaction of Apoptotic Cells with Macrophages Upregulates COX-2/PGE2and HGF Expression via a Positive Feedback Loop

2014 ◽  
Vol 2014 ◽  
pp. 1-17 ◽  
Author(s):  
Ji Yeon Byun ◽  
Young-So Youn ◽  
Ye-Ji Lee ◽  
Youn-Hee Choi ◽  
So-Yeon Woo ◽  
...  
Keyword(s):  
Positive Feedback ◽  
Tissue Repair ◽  
Feedback Loop ◽  
Apoptotic Cell ◽  
Raw 264.7 Cells ◽  
Apoptotic Cells ◽  
Positive Feedback Loop ◽  
Cox 2

Recognition of apoptotic cells by macrophages is crucial for resolution of inflammation, immune tolerance, and tissue repair. Cyclooxygenase-2 (COX-2)/prostaglandin E2 (PGE2) and hepatocyte growth factor (HGF) play important roles in the tissue repair process. We investigated the characteristics of macrophage COX-2 and PGE2expression mediated by apoptotic cells and then determined how macrophages exposed to apoptotic cellsin vitroandin vivoorchestrate the interaction between COX-2/PGE2and HGF signaling pathways. Exposure of RAW 264.7 cells and primary peritoneal macrophages to apoptotic cells resulted in induction of COX-2 and PGE2. The COX-2 inhibitor NS-398 suppressed apoptotic cell-induced PGE2production. Both NS-398 and COX-2-siRNA, as well as the PGE2receptor EP2 antagonist, blocked HGF expression in response to apoptotic cells. In addition, the HGF receptor antagonist suppressed increases in COX-2 and PGE2induction. Thein vivorelevance of the interaction between the COX-2/PGE2and HGF pathways through a positive feedback loop was shown in cultured alveolar macrophages followingin vivoexposure of bleomycin-stimulated lungs to apoptotic cells. Our results demonstrate that upregulation of the COX-2/PGE2and HGF in macrophages following exposure to apoptotic cells represents a mechanism for mediating the anti-inflammatory and antifibrotic consequences of apoptotic cell recognition.

scholarly journals Positive Feedback Loop of OCT4 and c-JUN Expedites Cancer Stemness in Liver Cancer

Stem Cells ◽  
2016 ◽  
Vol 34 (11) ◽  
pp. 2613-2624 ◽  
Author(s):  
Kung-Kai Kuo ◽  
King-Teh Lee ◽  
Ker-Kong Chen ◽  
Ya-Han Yang ◽  
Ying-Chu Lin ◽  
...  
Keyword(s):  
Liver Cancer ◽  
Positive Feedback ◽  
Feedback Loop ◽  
Cancer Stemness ◽  
Positive Feedback Loop

scholarly journals A Positive Feedback Loop of lncRNA MIR31HG-miR-361-3p -YY1 Accelerates Colorectal Cancer Progression Through Modulating Proliferation, Angiogenesis, and Glycolysis

2021 ◽  
Vol 11 ◽  
Author(s):  
Tao Guo ◽  
Defeng Liu ◽  
Shihao Peng ◽  
Meng Wang ◽  
Yangyang Li
Keyword(s):  
Colorectal Cancer ◽  
Cancer Progression ◽  
Positive Feedback ◽  
Feedback Loop ◽  
Luciferase Reporter ◽  
Loss Of Function ◽  
Positive Feedback Loop ◽  
Related Proteins

BackgroundColorectal cancer (CRC) is a common malignant tumor with high metastatic and recurrent rates. This study probes the effect and mechanism of long non-coding RNA MIR31HG on the progression of CRC cells.Materials and MethodsQuantitative real-time PCR (qRT-PCR) was used to analyze the expression of MIR31HG and miR-361-3p in CRC tissues and normal tissues. Gain- or loss-of-function assays were conducted to examine the roles of MIR31HG, miR-361-3p and YY1 transcription factor (YY1) in the CRC progression. 3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay, and colony formation experiment were conducted to test CRC cell proliferation. CRC cell invasion was determined by Transwell assay. The glucose detection kit and lactic acid detection kit were utilized to monitor the levels of glucose and lactate in CRC cells. The glycolysis level in CRC cells was examined by the glycolytic stress experiment. Western blot was performed to compare the expression of glycolysis-related proteins (PKM2, GLUT1 and HK2) and angiogenesis-related proteins (including VEGFA, ANGPT1, HIF1A and TIMP1) in HUVECs. The binding relationships between MIR31HG and miR-361-3p, miR-361-3p and YY1 were evaluated by the dual-luciferase reporter assay and RNA immunoprecipitation (RIP).ResultsMIR31HG was up-regulated in CRC tissues and was associated with poorer prognosis of CRC patients. The in-vitro and in-vivo experiments confirmed that overexpressing MIR31HG heightened the proliferation, growth, invasion, glycolysis and lung metastasis of CRC cells as well as the angiogenesis of HUVECs. In addition, MIR3HG overexpression promoted YY1 mRNA and protein level, and forced overexpression of YY1 enhanced MIR31HG level. Overexpressing YY1 reversed the tumor-suppressive effect mediated by MIR31HG knockdown. miR-361-3p, which was inhibited by MIR31HG overexpression, repressed the malignant behaviors of CRC cells. miR-361-3p-mediated anti-tumor effects were mostly reversed by upregulating MIR31HG. Further mechanism studies illustrated that miR-361-3p targeted and negatively regulated the expression of YY1.ConclusionThis study reveals that MIR31HG functions as an oncogenic gene in CRC via forming a positive feedback loop of MIR31HG-miR-361-3p-YY1.

scholarly journals Long Noncoding RNA HCG18 Promotes Malignant Phenotypes of Breast Cancer Cells via the HCG18/miR-103a-3p/UBE2O/mTORC1/HIF-1α–Positive Feedback Loop

2021 ◽  
Vol 9 ◽  
Author(s):  
Xu Liu ◽  
Kun Qiao ◽  
Kaiyuan Zhu ◽  
Xianglan Li ◽  
Chunbo Zhao ◽  
...  
Keyword(s):  
Breast Cancer ◽  
Positive Feedback ◽  
Noncoding Rna ◽  
Feedback Loop ◽  
Hypoxia Inducible Factor ◽  
The Cancer Genome Atlas ◽  
Positive Feedback Loop ◽  
Downstream Target

In recent years, an increasing number of studies have reported that long noncoding RNAs (lncRNAs) play crucial roles in breast cancer (BC) progression and metastasis. Another study group of our research center reported that lncRNA HCG18 was one of the 30 upregulated lncRNAs in BC tissues compared with normal tissues in The Cancer Genome Atlas database. However, the exact biological roles of HCG18 in BC remain unclear. In this study, we demonstrated that HCG18 is significantly upregulated in BC tissues and cells and that BC patients with high HCG18 expression tend to have poor prognosis. In vitro assays indicated that HCG18 promotes BC cell proliferation and invasion and endows BC cells with cancer stemness properties. In vivo assays revealed that reducing HCG18 expression in the BC cell line MDA-MB-231 markedly decreased tumor growth and lung metastasis in xenograft mouse models. In terms of mechanism, we found that HCG18 positively regulated the expression of BC-related ubiquitin-conjugating enzyme E2O (UBE2O) by sponging miR-103a-3p, and our previous research verified that UBE2O could promote the malignant phenotypes of BC cells through the UBE2O/AMPKα2/mTORC1 axis. Furthermore, as a downstream target of the HCG18/miR-103a-3p/UBE2O/mTORC1 axis, hypoxia-inducible factor 1α transcriptionally promoted HCG18 expression and then formed a positive feedback loop in BC. Taken together, these results confirm that HCG18 plays an oncogenic role in BC and might serve as a prognostic biomarker and a potential therapeutic target for BC treatment.

scholarly journals DNMT1-induced miR-378a-3p silencing promotes angiogenesis via the NF-κB signaling pathway by targeting TRAF1 in hepatocellular carcinoma

2021 ◽  
Vol 40 (1) ◽  
Author(s):  
Bin Zhu ◽  
Jun-Jie Chen ◽  
Ying Feng ◽  
Jun-Ling Yang ◽  
Hua Huang ◽  
...  
Keyword(s):  
Hepatocellular Carcinoma ◽  
Positive Feedback ◽  
Dna Methyltransferase ◽  
Feedback Loop ◽  
Tube Formation ◽  
Cell Counting ◽  
Luciferase Reporter ◽  
Positive Feedback Loop

Abstract Background Angiogenesis plays an important role in the occurrence, development and metastasis of hepatocellular carcinoma (HCC). According to previous studies, miR-378a participates in tumorigenesis and tumor metastasis, but its exact role in HCC angiogenesis remains poorly understood. Methods qRT-PCR was used to investigate the expression of miR-378a-3p in HCC tissues and cell lines. The effects of miR-378a-3p on HCC in vitro and in vivo were examined by Cell Counting Kit-8 (CCK-8), Transwell, tube formation and Matrigel plug assays, RNA sequencing, bioinformatics, luciferase reporter, immunofluorescence and chromatin immunoprecipitation (ChIP) assays were used to detect the molecular mechanism by which miR-378a-3p inhibits angiogenesis. Results We confirmed that miR-378a-3p expression was significantly downregulated and associated with higher microvascular density (MVD) in HCC; miR-378a-3p downregulation indicated a short survival time in HCC patients. miR-378a-3p knockdown led to a significant increase in angiogenesis in vitro and in vivo. We found that miR-378a-3p directly targeted TNF receptor associated factor 1 (TRAF1) to attenuate NF-κB signaling, and then downregulated secreted vascular endothelial growth factor. DNA methyltransferase 1 (DNMT1)-mediated hypermethylation of miR-378a-3p was responsible for downregulating miR-378a-3p. Moreover, a series of investigations indicated that p65 initiated a positive feedback loop that could upregulate DNMT1 to promote hypermethylation of the miR-378a-3p promoter. Conclusion Our study indicates a novel DNMT1/miR-378a-3p/TRAF1/NF-κB positive feedback loop in HCC cells, which may become a potential therapeutic target for HCC.

scholarly journals A Positive Feedback Loop of lncRNA-RMRP/ZNRF3 axis and Wnt/β-catenin Signaling Regulates Temozolomide Resistance in Glioma

2020 ◽  
Author(s):  
Tie Liu ◽  
Jie Hu ◽  
Bo Han ◽  
Shishan Tan ◽  
Wenqing Jia ◽  
...  
Keyword(s):  
Positive Feedback ◽  
Mrna Stability ◽  
Feedback Loop ◽  
Molecular Mechanisms ◽  
Glioma Cells ◽  
Positive Feedback Loop ◽  
Protein Levels ◽  
Glioma Xenograft ◽  
Rna Immunoprecipitation

Abstract Background: Drug resistance strikingly limits the therapeutic effect of temozolomide (TMZ) (a common drug for glioma). Long non-coding RNA (lncRNA) RMRP was found to be implicated in glioma progression. However, the effects of RMRP on TMZ resistance along with related molecular mechanisms are poor defined in glioma. Methods: RMRP, ZNRF3, and IGF2BP3 were screened out by bioinformatics analysis. The expression levels of lncRNAs and mRNAs were measured by RT-qPCR assay. Protein levels of genes were detected by western blot and immunofluorescence assays. ZNRF3 mRNA stability was analyzed using Actinomycin D assay. Cell proliferative ability and survival rate were determined by CCK-8 assay. Cell apoptotic patterns were estimated by flow cytometry. The effects of RMRP knockdown on the growth of TMZ-treated glioma xenograft tumors were explored in vivo. The relationships among IGF2BP3, RMRP and ZNRF3 were explored by bioinformatics prediction analysis, RNA immunoprecipitation and RNA pull-down assays. Results: RMRP was highly expressed in glioma. RMRP knockdown curbed cell proliferation, facilitated cell apoptosis and reduced TMZ resistance in glioma cells and hindered the growth of TMZ-treated glioma xenograft tumors. RMRP exerted its functions by down-regulating ZNRF3 in glioma cells. IGF2BP3 interacted with RMRP and ZNRF3 mRNA. RMRP reduced ZNRF3 expression and mRNA stability by IGF2BP3. RMRP knockdown inhibited β-catenin expression by up-regulating ZNRF3 and β-catenin promoted RMRP expression in glioma cells. Conclusion: RMRP/ZNRF3 axis and Wnt/β-catenin signaling formed a positive feedback loop to regulate TMZ resistance in glioma. The sustained activation of Wnt/β-catenin signaling by RMRP contributes the better management of cancers.

scholarly journals Qian Yang Yu Yin Granule Improves Renal Injury of Hypertension by Regulating Metabolic Reprogramming Mediated by HIF-1α/PKM2 Positive Feedback Loop

2021 ◽  
Vol 12 ◽  
Author(s):  
Lichao Qian ◽  
Shuai Ren ◽  
Zhongchi Xu ◽  
Yawei Zheng ◽  
Lihua Wu ◽  
...  
Keyword(s):  
Growth Factor ◽  
Positive Feedback ◽  
Feedback Loop ◽  
Transforming Growth Factor ◽  
Tissue Growth ◽  
Metabolic Reprogramming ◽  
Hypertensive Nephropathy ◽  
Positive Feedback Loop ◽  
Tgf Β1

Protection against hypoxia injury is an important therapeutic strategy for treating hypertensive nephropathy. In this study, the effects of Qian Yang Yu Yin granule (QYYY) on spontaneously hypertensive rats fed with high salt diet and HEK293T cells exposed to hypoxia were investigated. After eight weeks’ treatment of QYYY, blood pressure, serum creatinine, serum cystatin C, blood urea nitrogen, urinary β2-microglobulin, urinary N-acetyl-β-glucosaminidase, and urinary microalbumin were assessed. The changes of hypoxia-inducible factor-1α (HIF-1α), pyruvate kinase M2 (PKM2), glucose transport 1 (GLUT1), lactate dehydrogenase A (LDH-A), connective tissue growth factor (CTGF), transforming growth factor-β1 (TGF-β1), ATP, lactate, pyruvate, and pathology were also assessed in vivo. HEK293T cells pre-treated with QYYY and/or HIF-1α over expressing cells were cultured in a three gas hypoxic incubator chamber (5% CO2, 1% O2, 94% N2) for 12 h and then the expressions of HIF-1α, PKM2, GLUT1, LDH-A, CTGF, TGF-β1, ATP, lactate, and pyruvate were detected. Our results showed that QYYY promoted the indicators of renal inflammation and fibrosis mediated by HIF-1α/PKM2 positive feedback loop in vivo and vitro. Our findings indicated that QYYY treated hypertensive nephropathy by regulating metabolic reprogramming mediated by HIF-1α/PKM2 positive feedback loop.

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