scholarly journals Exosomal miR-1290 promotes angiogenesis in hepatocellular carcinoma via targeting SMEK1

2019 ◽  
Author(s):  
Qiong Wang ◽  
Guanwen Wang ◽  
Lianjie Niu ◽  
Shaorong Zhao ◽  
Jianjun Li ◽  
...  
Keyword(s):  
Hepatocellular Carcinoma ◽  
Endothelial Cells ◽  
Tumor Angiogenesis ◽  
Molecular Mechanisms ◽  
Target Genes ◽  
Primary Liver Cancer ◽  
Tumor Model ◽  
Luciferase Reporter ◽  
Dependent Manner

Abstract Abstract Background: Hepatocellular carcinoma (HCC), the most common primary liver cancer, rely on the formation of new blood vessel for growth and frequent intrahepatic and extrahepatic metastasis. Therefore, it is important to explore the underlying molecular mechanisms of tumor angiogenesis of HCC. Recently, microRNAs have been shown to modulate angiogenic processes by modulating the expression of critical angiogenic factors. However, the potential roles of tumor-derived exosomal microRNAs in regulating tumor angiogenesis remain to be elucidated. Methods: MiRNome sequencing was performed to uncover the miRNAs that are dysregulated in HCC patient serum-derived exosomes. Expression levels of miR-1290 in tissues and cells were determined by quantitative real-time PCR. The effect of mir-1290 on proliferation was evaluated by CCK-8 assay. The angiogenic ability of cells were determined by transwell, wound-healing, tube formation and matrigel plug assays. SMMC-7721 xenograft tumor model was established in NOD-SCID nude mice using miR-1290 and NC antagomirs to determin the angiogenic effect of mir-1290 in vivo. Target protein expression was determined by western blotting. Dual luciferase reporter assay was performed to confirm the action of miR-1290 on downstream target genes including SMEK1. Results are reported as means ± S.D. and differences were tested for significance using 2-sided Student’s t-test. Results: In this study, our miRNome sequencing demonstrated that miR-1290 was overexpressed in HCC patient serum-derived exosomes, and we found that delivery of miR-1290 into human endothelial cells enhanced their angiogenic ability. Our results further revealed that SMEK1 is a direct target of miR-1290 in endothelial cells. MiR-1290 exerted its pro-angiogenic function, at least in part, by inhibiting the VEGFR2 signaling pathway in a SMEK1-dependent manner. Conclusions: Collectively, our findings provide evidence that miR-1290 is overexpressed in HCC and promotes tumor angiogenesis via exosomal secretion, implicating its potential role as a therapeutic target for HCC.

scholarly journals Exosomal miR-1290 promotes angiogenesis in hepatocellular carcinoma via targeting SMEK1

2020 ◽  
Author(s):  
Qiong Wang ◽  
Guanwen Wang ◽  
Lianjie Niu ◽  
Shaorong Zhao ◽  
Jianjun Li ◽  
...  
Keyword(s):  
Hepatocellular Carcinoma ◽  
Endothelial Cells ◽  
Tumor Angiogenesis ◽  
Molecular Mechanisms ◽  
Target Genes ◽  
Primary Liver Cancer ◽  
Tumor Model ◽  
Tube Formation ◽  
Luciferase Reporter

Abstract Background: Hepatocellular carcinoma (HCC), the most common primary liver cancer, rely on the formation of new blood vessel for growth and frequent intrahepatic and extrahepatic metastasis. Therefore, it is important to explore the underlying molecular mechanisms of tumor angiogenesis of HCC. Recently, microRNAs have been shown to modulate angiogenic processes by modulating the expression of critical angiogenic factors. However, the potential roles of tumor-derived exosomal microRNAs in regulating tumor angiogenesis remain to be elucidated. Methods: MiRNome sequencing was performed to uncover the miRNAs that are dysregulated in HCC patient serum-derived exosomes. Expression levels of miR-1290 in tissues and cells were determined by quantitative real-time PCR. The effect of mir-1290 on proliferation was evaluated by CCK-8 assay. The angiogenic ability of cells were determined by transwell, wound-healing, tube formation and matrigel plug assays. SMMC-7721 xenograft tumor model was established in NOD-SCID nude mice using miR-1290 and NC antagomirs to determin the angiogenic effect of mir-1290 in vivo. Target protein expression was determined by western blotting. Dual luciferase reporter assay was performed to confirm the action of miR-1290 on downstream target genes including SMEK1. Results are reported as means ± S.D. and differences were tested for significance using 2-sided Student’s t-test.Results: In this study, our miRNome sequencing demonstrated that miR-1290 was overexpressed in HCC patient serum-derived exosomes, and we found that delivery of miR-1290 into human endothelial cells enhanced their angiogenic ability. Our results further revealed that SMEK1 is a direct target of miR-1290 in endothelial cells. MiR-1290 exerted its pro-angiogenic function, at least in part, by alleviating the inhibition of VEGFR2 phosphorylation done by SMEK1. Conclusions: Collectively, our findings provide evidence that miR-1290 is overexpressed in HCC and promotes tumor angiogenesis via exosomal secretion, implicating its potential role as a therapeutic target for HCC.

scholarly journals Epigenetic regulation of ferroptosis via ETS1/miR-23a-3p/ACSL4 axis mediates sorafenib resistance in human hepatocellular carcinoma

2022 ◽  
Vol 41 (1) ◽  
Author(s):  
Yuanjun Lu ◽  
Yau-Tuen Chan ◽  
Hor-Yue Tan ◽  
Cheng Zhang ◽  
Wei Guo ◽  
...  
Keyword(s):  
Hepatocellular Carcinoma ◽  
Drug Resistance ◽  
Molecular Mechanisms ◽  
Luciferase Reporter ◽  
Dependent Manner ◽  
Bioinformatics Analyses ◽  
Sorafenib Treatment ◽  
Hcc Cells

Abstract Background Drug resistance to sorafenib greatly limited the benefits of treatment in patients with hepatocellular carcinoma (HCC). MicroRNAs (miRNAs) participate in the development of drug resistance. The key miRNA regulators related to the clinical outcome of sorafenib treatment and their molecular mechanisms remain to be identified. Methods The clinical significance of miRNA-related epigenetic changes in sorafenib-resistant HCC was evaluated by analyzing publicly available databases and in-house human HCC tissues. The biological functions of miR-23a-3p were investigated both in vitro and in vivo. Proteomics and bioinformatics analyses were conducted to identify the mechanisms that regulating miR-23a-3p. Luciferase reporter assay and chromatin immunoprecipitation (ChIP) assay were used to validate the binding relationship of miR-23a-3p and its targets. Results We found that miR-23a-3p was the most prominent miRNA in HCC, which was overexpressed in sorafenib non-responders and indicated poor survival and HCC relapse. Sorafenib-resistant cells exhibited increased miR-23a-3p transcription in an ETS Proto-Oncogene 1 (ETS1)-dependent manner. CRISPR-Cas9 knockout of miR-23a-3p improved sorafenib response in HCC cells as well as orthotopic HCC tumours. Proteomics analysis suggested that sorafenib-induced ferroptosis was the key pathway suppressed by miR-23a-3p with reduced cellular iron accumulation and lipid peroxidation. MiR-23a-3p directly targeted the 3′-untranslated regions (UTR) of ACSL4, the key positive regulator of ferroptosis. The miR-23a-3p inhibitor rescued ACSL4 expression and induced ferrotoptic cell death in sorafenib-treated HCC cells. The co-delivery of ACSL4 siRNA and miR-23a-3p inhibitor abolished sorafenib response. Conclusion Our study demonstrates that ETS1/miR-23a-3p/ACSL4 axis contributes to sorafenib resistance in HCC through regulating ferroptosis. Our findings suggest that miR-23a-3p could be a potential target to improve sorafenib responsiveness in HCC patients.

Abstract 267: Opposing Functions of Two Splice Variants of the Human Transcription Factor Grainyhead-like 3 in Endothelial Cells And in vivo

2013 ◽  
Vol 113 (suppl_1) ◽  
Author(s):  
Joachim Altschmied ◽  
Nicole Büchner ◽  
Sascha Jakob ◽  
Sabrina Farrokh ◽  
Christine Goy ◽  
...  
Keyword(s):  
Endothelial Cells ◽  
Transcription Factor ◽  
Transcription Factors ◽  
Target Genes ◽  
Splice Variants ◽  
Luciferase Reporter ◽  
Dependent Manner ◽  
Active Transcription ◽  
Human Transcription Factor

Grainyhead-like 3 (GRHL3) is a member of the evolutionary conserved Grainyhead family of transcription factors. In humans, three isoforms are derived from differential first exon usage and alternative splicing, which differ only in their N-terminus. Isoform 2, the only variant also present in mouse, is required for endothelial cell (EC) migration and protects against apoptosis. The functions of the human specific isoforms 1 and 3, which are derived from an alternatively spliced pre-mRNA, have not yet been investigated, although all three isoforms are expressed in EC. Therefore, we have assessed their effects on EC migration and apoptosis. Overexpression of the two proteins had opposite effects on EC migration, with isoform 1 acting pro-migratory. This protein also protected EC against apoptosis in an eNOS-dependent manner, whereas isoform 3 had no effect. These opposing outcomes with respect to apoptosis EC were corroborated by isoform-specific knockdowns. With reporter assays using a GRHL3-specific luciferase reporter we demonstrated that both are active transcription factors. Microarray analyses revealed that they induce divergent target gene sets in EC. Two validated targets, Akt2 and Mxi1, which are upregulated by isoform1, are regulators of Akt1-, and thus eNOS-phosphorylation and apoptosis, which could explain the effects of this protein on these processes. In vivo, overexpression of isoform 3 in zebrafish embryos resulted in increased lethality and severe deformations, while isoform 1 had no deleterious effect. In conclusion, our data demonstrate that the splice variant derived isoforms 1 and 3 of the human transcription factor GRHL3 induce opposing effects in primary human endothelial cells and in a whole animal model, most likely through the induction of different target genes.

scholarly journals Exosomal MiR-1290 Promotes Angiogenesis of Hepatocellular Carcinoma via Targeting SMEK1

2021 ◽  
Vol 2021 ◽  
pp. 1-13
Author(s):  
Qiong Wang ◽  
Guanwen Wang ◽  
Lianjie Niu ◽  
Shaorong Zhao ◽  
Jianjun Li ◽  
...  
Keyword(s):  
Hepatocellular Carcinoma ◽  
Endothelial Cells ◽  
Liver Cancer ◽  
Blood Vessel ◽  
Tumor Angiogenesis ◽  
Molecular Mechanisms ◽  
Potential Role ◽  
Primary Liver Cancer ◽  
Human Endothelial Cells ◽  
Direct Target

Hepatocellular carcinoma (HCC), the most common primary liver cancer, relies on the formation of new blood vessel for growth and frequent intrahepatic and extrahepatic metastasis. Therefore, it is important to explore the underlying molecular mechanisms of tumor angiogenesis of HCC. Recently, microRNAs have been shown to modulate angiogenic processes by modulating the expression of critical angiogenic factors. However, the potential roles of tumor-derived exosomal microRNAs in regulating tumor angiogenesis remain to be elucidated. In this study, our miRNome sequencing demonstrated that miR-1290 was overexpressed in HCC patient serum-derived exosomes, and we found that delivery of miR-1290 into human endothelial cells enhanced their angiogenic ability. Our results further revealed that SMEK1 is a direct target of miR-1290 in endothelial cells. MiR-1290 exerted its proangiogenic function, at least in part, by alleviating the inhibition of VEGFR2 phosphorylation done by SMEK1. Collectively, our findings provide evidence that miR-1290 is overexpressed in HCC and promotes tumor angiogenesis via exosomal secretion, implicating its potential role as a therapeutic target for HCC.

scholarly journals Apigenin Inhibits the Growth of Hepatocellular Carcinoma Cells by Affecting the Expression of microRNA Transcriptome

2021 ◽  
Vol 11 ◽  
Author(s):  
Shou-Mei Wang ◽  
Pei-Wei Yang ◽  
Xiao-Jun Feng ◽  
Yi-Wei Zhu ◽  
Feng-Jun Qiu ◽  
...  
Keyword(s):  
Hepatocellular Carcinoma ◽  
Cell Cycle ◽  
Molecular Mechanisms ◽  
Target Genes ◽  
Dependent Manner ◽  
Regulatory Pathways ◽  
The Core ◽  
Huh7 Cells

BackgroundApigenin, as a natural flavonoid, has low intrinsic toxicity and has potential pharmacological effects against hepatocellular carcinoma (HCC). However, the molecular mechanisms involving microRNAs (miRNAs) and their target genes regulated by apigenin in the treatment of HCC have not been addressed.ObjectiveIn this study, the molecular mechanisms of apigenin involved in the prevention and treatment of HCC were explored in vivo and in vitro using miRNA transcriptomic sequencing to determine the basis for the clinical applications of apigenin in the treatment of HCC.MethodsThe effects of apigenin on the proliferation, cell cycle progression, apoptosis, and invasion of human hepatoma cell line Huh7 and Hep3B were studied in vitro, and the effects on the tumorigenicity of Huh7 cells were assessed in vivo. Then, a differential expression analysis of miRNAs regulated by apigenin in Huh7 cells was performed using next-generation RNA sequencing and further validated by qRT-PCR. The potential genes targeted by the differentially expressed miRNAs were identified using a curated miRTarBase miRNA database and their molecular functions were predicted using Gene Ontology and KEGG signaling pathway analysis.ResultsCompared with the control treatment group, apigenin significantly inhibited Huh7 cell proliferation, cell cycle, colony formation, and cell invasion in a concentration-dependent manner. Moreover, apigenin reduced tumor growth, promoted tumor cell necrosis, reduced the expression of Ki67, and increased the expression of Bax and Bcl-2 in the xenograft tumors of Huh7 cells. Bioinformatics analysis of the miRNA transcriptome showed that hsa-miR-24, hsa-miR-6769b-3p, hsa-miR-6836-3p, hsa-miR-199a-3p, hsa-miR-663a, hsa-miR-4739, hsa-miR-6892-3p, hsa-miR-7107-5p, hsa-miR-1273g-3p, hsa-miR-1343, and hsa-miR-6089 were the most significantly up-regulated miRNAs, and their key gene targets were MAPK1, PIK3CD, HRAS, CCND1, CDKN1A, E2F2, etc. The core regulatory pathways of the up-regulated miRNAs were associated with the hepatocellular carcinoma pathway. The down-regulated miRNAs were hsa-miR-181a-5p and hsa-miR-148a-3p, and the key target genes were MAPK1, HRAS, STAT3, FOS, BCL2, SMAD2, PPP3CA, IFNG, MET, and VAV2, with the core regulatory pathways identified as proteoglycans in cancer pathway.ConclusionApigenin can inhibit the growth of HCC cells, which may be mediated by up-regulation or down-regulation of miRNA molecules and their related target genes.

scholarly journals MAZ-LINC00645-GP73 Axis Promotes Hepatocellular Carcinoma Proliferation and Metastasis

2020 ◽  
Author(s):  
Yang Chen ◽  
Huiyan Li ◽  
Chunxun Liu ◽  
Yongmei Han ◽  
Yubao Zhang ◽  
...  
Keyword(s):  
Hepatocellular Carcinoma ◽  
Molecular Mechanisms ◽  
Tumor Promoter ◽  
Transcriptional Analysis ◽  
Luciferase Reporter ◽  
Chip Assay ◽  
Bioinformatics Analyses

Abstract BACKGROUND: Long non-coding RNAs (lncRNA) have been shown to play important roles in the development and progression of hepatocellular carcinoma (HCC). In this report, we examined the role of lncRNA LINC00645 in HCC. MATERIAL AND METHODS: Based on public databases and integrating bioinformatics analyses, the over-expression of LINC00645 in HCC tissues was detected and further validated in a cohort of liver tissues. A series of in vitro and in vivo functional experiments were executed to investigate the role of LINC00645 in the carcinogenesis and development of HCC. Comprehensive transcriptional analysis, chromatin immunoprecipitation (ChIP) assay, dual-luciferase reporter assay and western blot etc. were performed to explore the molecular mechanisms underlying the functions of LINC00645. RESULTS: LINC00645 was significantly upregulated in HCC cell lines and HCC tissues, which was correlated with poor prognosis in HCC patients. LINC00645 knockdown remarkably suppressed tumor growth in vitro and in vivo. Mechanistically, LINC00645 could competitively bind with miR-141-3p to prevent the degradation of its target gene GP73, which acts as a tumor-promoter in HCC. Furthermore, the ChIP assay showed that the transcription factor MAZ could bind to the LINC00645 promoter and increase its transcription. CONCLUSIONS: Collectively, this study demonstrated that LINC00645 plays a critical regulatory role in hepatocellular carcinoma cells and LINC00645 may serve as a potential diagnostic biomarker and therapeutic target of HCC. Thus, targeting MAZ/LINC00645/miR-141-3p/GP73 signaling axis may prevent the progression of HCC.

scholarly journals Exosomal miR-199a-5p Inhibits Tumorigenesis and Angiogenesis by Targeting VEGFA in Osteosarcoma

2021 ◽  
Author(s):  
Lu Zhang ◽  
Hongxin Cao ◽  
Guanghui Gu ◽  
Dehui Hou ◽  
Yunhao You ◽  
...  
Keyword(s):  
Molecular Mechanisms ◽  
Target Genes ◽  
Enrichment Analysis ◽  
Luciferase Reporter ◽  
Pathway Enrichment Analysis ◽  
Osteosarcoma Cell ◽  
Plasma Samples ◽  
Osteosarcoma Cells ◽  
Hub Genes

Abstract Background: Osteosarcoma (OS) is the most common primary bone malignancy in children and adolescents. microRNAs have been found to play a vital role in tumor angiogenesis. Here, we investigated the effects of miR-199a-5p on tumor growth and angiogenesis in osteosarcoma. Furthermore, the underlying molecular mechanisms and signaling pathways were explored.Methods: The datasets were extracted from the Gene Expression Omnibus and the differentially expressed miRNAs (DEmiRNAs) were screened out by the GEO2R online platform. The potential target genes were predicted using the miRTarBase database. The predicted target genes were further analyzed by Gene Ontology and pathway enrichment analysis and a regulatory network of DEmiRNAs and their target genes was constructed. In addition, the effects of osteosarcoma cell derived exosomal miR-199a-5p on the proliferation, migration and neovascularization of HUVECs were evaluated by conducting EdU assays, Transwell experiments and tube formation assays. A dual-luciferase reporter assay was performed to detect whether VEGFA was the direct target of miR-199a-5p. Furthermore, in vivo xenograft models were established to further investigate the intrinsic role of miR-199a-5p in osteosarcoma tumorigenesis and angiogenesis. Results: A total of 149 DE-miRNAs were screened out, including 136 upregulated miRNAs and 13 downregulated miRNAs in human osteosarcoma plasma samples compared with normal plasma samples. A total of 1313 target genes of the top three upregulated and downregulated miRNAs were predicted. In the PPI network, the top 10 hub nodes with higher degrees were identified as hub genes, such as TP53 and VEGFA. By constructing the miRNA-hub gene network, we found that most of hub genes could be potentially modulated by miR-663a, miR-199a-5p and miR-223-3p. In addition, we found that the expression level of miR-199a-5p in exosomes derived from osteosarcoma cells was remarkably higher than the osteosarcoma cells, and the exosomes derived from osteosarcoma cells were transported to HUVECs. Overexpression of miR-199a-5p could significantly inhibited HUVEC proliferation, migration and neovascularization, whereas downregulation of miR-199a-5p expression exerted the opposite effect. Moreover, the in vivo results verified that overexpression of miR-199a-5p in osteosarcoma cells could suppress the growth and angiogenesis of tumors. Conclusion: Our results demonstrated that miR-199a-5p could be transported from osteosarcoma cells to HUVECs through exosomes, subsequently targeting VEGFA and inhibiting the growth and angiogenesis of osteosarcoma. Therefore, miR-199a-5p may act as a biomarker in the diagnosis and treatment of osteosarcoma.

scholarly journals EPC-Derived Exosomal miR-1246 and miR-1290 Regulate Phenotypic Changes of Fibroblasts to Endothelial Cells to Exert Protective Effects on Myocardial Infarction by Targeting ELF5 and SP1

2021 ◽  
Vol 9 ◽  
Author(s):  
Yulang Huang ◽  
Lifang Chen ◽  
Zongming Feng ◽  
Weixin Chen ◽  
Shaodi Yan ◽  
...  
Keyword(s):  
Myocardial Infarction ◽  
Endothelial Cells ◽  
Molecular Mechanisms ◽  
Cardiac Injury ◽  
Immunofluorescence Staining ◽  
Luciferase Reporter ◽  
Protective Effects ◽  
Expression Levels ◽  
Phenotypic Changes

Myocardial infarction (MI) remains a leading cause of morbidity and mortality worldwide. Endothelial progenitor cell (EPC)-derived exosomes have been found to be effective in alleviating MI, while the detailed mechanisms remain unclear. The present study aimed to determine the protective effects of EPC-derived exosomal miR-1246 and miR-1290 on MI-induced injury and to explore the underlying molecular mechanisms. The exosomes were extracted from EPCs; gene expression levels were determined by quantitative real-time PCR, and protein expression levels were determined by western blot and immunofluorescence staining, respectively. The angiogenesis and proliferation of human cardiac fibroblasts (HCFs) were determined by tube formation assay and immunofluorescence staining of PKH67, respectively. Luciferase reporter, CHIP, and EMSA assays determined the interaction between miR-1246/1290 and the targeted genes (EFL5 and SP1). The protective effects of miR-1246/1290 on MI were evaluated in a rat model of MI. EPC-derived exosomes significantly upregulated miR-1246 and miR-1290 expression and promoted phenotypic changes of fibroblasts to endothelial cells, angiogenesis, and proliferation in HCFs. Exosomes from EPCs with miR-1246 or miR-1290 mimics transfection promoted phenotypic changes of fibroblasts to endothelial cells and angiogenesis in HCFs, while exosomes from EPCs with miR-1246 or miR-1290 knockdown showed opposite effects in HCFs. Mechanistically, miR-1246 and miR-1290 from EPC-derived exosomes induced upregulation of ELF5 and SP1, respectively, by targeting the promoter regions of corresponding genes. Overexpression of both ELF5 and SP1 enhanced phenotypic changes of fibroblasts to endothelial cells and angiogenesis in HCFs pretreated with exosomes from EPCs with miR-1246 or miR-1290 mimics transfection, while knockdown of both EFL5 and SP1 exerted the opposite effects in HCFs. Both ELF5 and SP1 can bind to the promoter of CD31, leading to the upregulation of CD31 in HCFs. Furthermore, in vivo animal studies showed that exosomes from EPCs with miR-1246 or miR-1290 overexpression attenuated the MI-induced cardiac injury in the rats and caused an increase in ELF5, SP1, and CD31 expression, respectively, but suppressed α-SMA expression in the cardiac tissues. In conclusion, our study revealed that miR-1246 and miR-1290 in EPC-derived exosomes enhanced in vitro and in vivo angiogenesis in MI, and these improvements may be associated with amelioration of cardiac injury and cardiac fibrosis after MI.

scholarly journals The Long Non-coding RNA TMPO-AS1  Promotes Bladder Cancer Growth and Progression via OTUB1-induced E2F1 Deubiquitination

2020 ◽  
Author(s):  
Yeyu Zhang ◽  
Yuxing Zhu ◽  
Mengqing Xiao ◽  
Yaxin Cheng ◽  
Dong He ◽  
...  
Keyword(s):  
Bladder Cancer ◽  
Molecular Mechanisms ◽  
Luciferase Reporter ◽  
Migration And Invasion ◽  
Dependent Manner ◽  
E2f Transcription Factor ◽  
Rna Immunoprecipitation ◽  
Regulatory Loop

Abstract BackgroundBladder cancer (BC) is the most common malignant tumor of the urinary system. Increasing evidence indicates long non-coding RNAs (lncRNAs) play crucial roles in cancer tumorigenesis, development, and progression. However, the role of TMPO antisense RNA 1 (TMPO-AS1) is still need to be explored in BC.MethodsThe lncRNA TMPO-AS1 expression was evaluated by bioinformatics analysis and further validated by qRT-PCR. Loss- and gain-of- function assays were performed to determine the biological functions of TMPO-AS1 in BC proliferation, migration, and invasion. Chromatin immunoprecipitation, luciferase reporter assays, western blotting, RNA pull-down, RNA immunoprecipitation assays, and fluorescence in situ hybridization were conducted to explore the molecular mechanisms of TMPO-AS1/E2F transcription factor 1 (E2F1) loop. ResultsTMPO-AS1 is upregulated in bladder cancer and is associated with BC patients’ poor prognoses. Functional experiments demonstrated that TMPO-AS1 promotes bladder cancer cell proliferation, migration, invasion, and inhibits cell apoptosis in vivo and in vitro. Mechanically, E2F1 is responsible for the TMPO-AS1 upregulation. Additionally, TMPO-AS1 facilitates the interaction of E2F1 with OTU domain-containing ubiquitin aldehyde binding 1 (OTUB1), leading to E2F1 deubiquitination and stabilization, thereby promotes BC malignant phenotypes. Furthermore, rescue experiments showed that TMPO-AS1 promotes BC growth in an E2F1-dependent manner.ConclusionsOur study is the first to uncover a novel positive regulatory loop of TMPO-AS1/E2F1 important for the promotion of BC malignant behaviors. The TMPO-AS1/E2F1 loop should be considered in the quest for new BC therapeutic options.

Heparins Inhibit Tumor Angiogenesis by Sequestering Fibroblast Growth Factor (FGF) from Tumor Vascular Endothelial Cells.

Blood ◽  
2005 ◽  
Vol 106 (11) ◽  
pp. 2662-2662
Author(s):  
Shannon L. Smiley ◽  
Dale O. Henry ◽  
Shang-Chiung Chen ◽  
Michael K.K. Wong
Keyword(s):  
Endothelial Cells ◽  
Growth Factor ◽  
Fibroblast Growth Factor ◽  
Tumor Angiogenesis ◽  
Experimental Models ◽  
Control Group ◽  
Molecular Evidence ◽  
Dependent Manner ◽  
Fibroblast Growth

Abstract The association between cancer and thromboembolic disease is a well-known phenomenon and contributes to the morbidity and mortality of cancer patients. Clinical studies of thrombosis in these patients show that heparins may have beneficial effects on survival. Antithrombotic agents have been shown to exert an anti-tumor effect in various experimental models however the underlying mechanism remains unknown. We show that heparins inhibit in vivo tumor angiogenesis and offer molecular evidence that heparins exert an anti-angiogenic effect by directly sequestering fibroblast growth factor (FGF) from its receptor on tumor derived endothelial cells (TDECs). NIH-3T3 fibroblasts were stably transfected with an expression construct that results in the constitutive excretion of FGF-1 (Clone C). Clone C gives rise to aggressive and highly angiogenic xenograft tumors. Clone C was inoculated into nude mice and therapeutic doses of Low Molecular Weight (LMW) heparins were injected daily beginning on Day 2. Tumors in the control group were grossly angiogenic and highly vascularized. In contrast, the heparin treated tumors were pale and possessed only scant peri-tumoral vessels. In order to assess the biologic mechanism of this, murine TDECs were isolated and cultured as previously published. Unfractionated and LMW heparins inhibit FGF-induced TDEC mitogenesis in a concentration- and time-dependent manner. FGF overcame and rescued heparin-induced inhibition suggesting that an FGF-heparin interaction is responsible. In order to test the hypothesis that heparin strips and sequesters FGF off its receptor on TDECs, we used a FGF protein fused to a hemagglutinin peptide tag at the carboxyl-terminus end (FGF-HA). FGF-HA is biologically identical to wild type FGF, but its detection limit is 10X more sensitive. FGF-HA was allowed to bind to FGFR on TDECs. These cells were subsequently incubated with Heparin covalently linked to Sepharose beads (Heparin-Sepharose) or to Sepharose alone. These beads were removed, and TDEC growth analyzed prospectively. Heparin-Sepharose treatment results in significant TDEC growth inhibition as compared to incubation with Sepharose alone. Western blot analysis shows that FGF was sequestered only on the Heparin-Sepharose beads. Conclusion: The anti-angiogenic mechanism of heparins resides, in part, in its ability to sequester angiogenic cytokines such as FGF from its receptor on tumor endothelium.

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