Role of microRNA-27a in down-regulation of angiogenic factor AGGF1 under hypoxia associated with high-grade bladder urothelial carcinoma

Regulation of Cancer-Associated miRNAs Expression under Hypoxic Conditions

Solid tumors frequently experience hypoxia or low O2 levels. In these conditions, hypoxia-inducible factor 1 alpha (HIF-1α) is activated and acts as a transcription factor that regulates cancer cell adaptation to O2 and nutrient deprivation. HIF-1α controls gene expression associated with various signaling pathways that promote cancer cell proliferation and survival. MicroRNAs (miRNAs) are 22-nucleotide noncoding RNAs that play a role in various biological processes essential for cancer progression. This review presents an overview of how hypoxia regulates the expression of multiple miRNAs in the progression of cancer cells.

Cardiac Biomarkers and Their Role in Identifying Increased Risk of Cardiovascular Complications in COVID-19 Patients

Cardiovascular disease (CVD) is a global health concern, causing significant morbidity and mortality. Both lifestyle and genetics influence the development of CVD. It is often diagnosed late, when the treatment options are limited. Early diagnosis of CVD with help of biomarkers is necessary to prevent adverse outcomes. SARS-CoV-2 infection can cause cardiovascular complications even in patients with no prior history of CVD. This review highlights cardiovascular biomarkers, including novel ones, and their applications as diagnostic and prognostic markers of cardiovascular complications related to SARS-CoV-2 infection. Patients with severe SARS-CoV-2 infection were shown to have elevated levels of cardiac biomarkers, namely N-terminal pro-brain natriuretic peptide (NT-pro-BNP), creatine kinase-myocardial band (CK-MB), and troponins, indicating acute myocardial damage. These biomarkers were also associated with higher mortality rates and therefore should be used throughout COVID-19 patient care to identify high-risk patients promptly to optimize their outcomes. Additionally, microRNAs (miRNAs) are also considered as potential biomarkers and predictors of cardiac and vascular damage in SARS-CoV-2 infection. Identifying molecular pathways contributing to cardiovascular manifestations in COVID-19 is essential for development of early biomarkers, identification of new therapeutic targets, and better prediction and management of cardiovascular outcomes.

An Overview of Angiogenesis in Bladder Cancer

PURPOSE OF THE REVIEW

Angiogenesis plays a key role in bladder cancer (BC) pathogenesis. In the last two decades, an increasing number of publications depicting a multitude of novel angiogenic molecules and pathways have emerged. The growing complexity necessitates an evaluation of the breadth of current knowledge to highlight key findings and guide future research.

RECENT FINDINGS

Angiogenesis is a dynamic biologic process that is inherently difficult to assess. Clinical assessment of angiogenesis in BCs is advancing with the integration of image analysis systems and dynamic contrast-enhanced and magnetic resonance imaging (DCE-MRI). Tumour-associated macrophages (TAMs) significantly influence the angiogenic process, and further research is needed to assess their potential as therapeutic targets. A rapidly growing list of non-coding RNAs affect angiogenesis in BCs, partly through modulation of vascular endothelial growth factor (VEGF) activity. Vascular mimicry (VM) has been repeatedly associated with increased tumour aggressiveness in BCs. Standardised assays are needed for appropriate identification and quantification of VM channels. This article demonstrates the dynamic and complex nature of the angiogenic process and asserts the need for further studies to deepen our understanding.

Decreased AGGF1 facilitates the progression of placenta accreta spectrum via mediating the P53 signaling pathway under the regulation of miR-1296-5p

Placenta accreta spectrum (PAS), an emerging health issue worldwide, is the major causative factor of maternal morbidity and mortality in modern obstetrics, but limited studies have contributed to our understanding of the molecular biology of PAS. This study addressed the expression of AGGF1 and its specific role in the etiology of PAS. The expression of AGGF1 in the placentas of PAS was determined by quantitative PCR, western blot and immunohistochemistry. CCK-8 assay, wound healing assay, Transwell invasion assay and flow cytometry assay were performed to monitor cell proliferation, migration, invasion and apoptosis. The interaction between miR-1296-5p and AGGF1 was detected by dual-luciferase reporter gene assay. Results showed that the mRNA and protein expression of AGGF1 was decremented in placental tissues of PAS patients, compared with samples from women with placenta previa and normal pregnant women. Downregulation of AGGF1 promoted cell proliferation, invasion and migration, inhibited apoptosis in vitro, decreased P53 and Bax expression, and simultaneously increased Bcl-2 expression, whereas overexpression of AGGF1 had the opposite results. Additionally, the dual-luciferase assay confirmed AGGF1 as a target gene of miR-1296-5p in placental tissues of PAS. Particularly, miR-1296-5p fostered HTR8/SVneo cell proliferation, invasion, repression of apoptosis and regulation of P53 signaling axis by downregulating AGGF1 expression. Collectively, our study accentuated that downregulation of placental AGGF1 promoted trophoblast over-invasion by mediating the P53 signaling pathway under the regulation of miR-1296-5p.

Alterations in Circulating miRNA Levels after Infection with SARS-CoV-2 Could Contribute to the Development of Cardiovascular Diseases: What We Know So Far

The novel coronavirus disease 2019 (COVID-19) is caused by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and poses significant complications for cardiovascular disease (CVD) patients. MicroRNAs (miRNAs) are small non-coding RNAs that regulate gene expression and influence several physiological and pathological processes, including CVD. This critical review aims to expand upon the current literature concerning miRNA deregulation during the SARS-CoV-2 infection, focusing on cardio-specific miRNAs and their association with various CVDs, including cardiac remodeling, arrhythmias, and atherosclerosis after SARS-CoV-2 infection. Despite the scarcity of research in this area, our findings suggest that changes in the expression levels of particular COVID-19-related miRNAs, including miR-146a, miR-27/miR-27a-5p, miR-451, miR-486-5p, miR-21, miR-155, and miR-133a, may be linked to CVDs. While our analysis did not conclusively determine the impact of SARS-CoV-2 infection on the profile and/or expression levels of cardiac-specific miRNAs, we proposed a potential mechanism by which the miRNAs mentioned above may contribute to the development of these two pathologies. Further research on the relationship between SARS-CoV-2, CVDs, and microRNAs will significantly enhance our understanding of this connection and may lead to the use of these miRNAs as biomarkers or therapeutic targets for both pathologies.

Interactome battling of lncRNA CCDC144NL-AS1: Its role in the emergence and ferocity of cancer and beyond

Long non-coding RNAs (lncRNAs) were, once, viewed as "noise" for transcription. Recently, many lncRNAs are functionally linked to several human disorders, including cancer. Coiled-Coil Domain Containing 144 N-Terminal-Like antisense1 (CCDC144NL-AS1) is a newly discovered cytosolic lncRNA. Aberrant CCDC144NL-AS1 expression was discovered in hepatocellular carcinoma (HCC), ovarian cancer (OC), gastric cancer (GC), non-small cell lung cancer (NSCLC), and osteosarcoma. CCDC144NL-AS1 could be a promising prognostic biological marker and therapeutic target for cancer. In this review, we will collect and highlight the available information about CCDC144NL-AS1 role in various cancers. Moreover, we will discuss the diagnostic and prognostic utility of CCDC144NL-AS1 as a new molecular biomarker for several human malignancies, besides its potential therapeutic importance.

Endothelial cell metabolic memory causes cardiovascular dysfunction in diabetes

AIMS

The aim of this study was to identify the molecular mechanism for hyperglycaemia-induced metabolic memory in endothelial cells (ECs), and to show its critical importance to development of cardiovascular dysfunction in diabetes.

METHODS AND RESULTS

Hyperglycaemia induces increased nuclear factor-κB (NF-κB) signalling, up-regulation of miR-27a-3p, down-regulation of nuclear factor erythroid-2 related factor 2 (NRF2) expression, increased transforming growth factor-β (TGF-β) signalling, down-regulation of miR-29, and induction of endothelial-to-mesenchymal transition (EndMT), all of which are memorized by ECs and not erased when switched to a low glucose condition, thereby causing perivascular fibrosis and cardiac dysfunction. Similar metabolic memory effects are found for production of nitric oxide (NO), generation of reactive oxygen species (ROS), and the mitochondrial oxygen consumption rate in two different types of ECs. The observed metabolic memory effects in ECs are blocked by NRF2 activator tert-butylhydroquinone and a miR-27a-3p inhibitor. In vivo, the NRF2 activator and miR-27a-3p inhibitor block cardiac perivascular fibrosis and restore cardiovascular function by decreasing NF-κB signalling, down-regulating miR-27a-3p, up-regulating NRF2 expression, reducing TGF-β signalling, and inhibiting EndMT during insulin treatment of diabetes in streptozotocin-induced diabetic mice, whereas insulin alone does not improve cardiac function.

CONCLUSIONS

Our data indicate that disruption of hyperglycaemia-induced EC metabolic memory is required for restoring cardiac function during treatment of diabetes, and identify a novel molecular signalling pathway of NF-κB/miR-27a-3p/NRF2/ROS/TGF-β/EndMT involved in metabolic memory.

Circulating miRNA 27a and miRNA150-5p; a noninvasive approach to endometrial carcinoma

The search for novel non-invasive biomarkers such as epigenetic molecular markers is new hope for common and burdensome cancers. We aim to assess serum expression of miRNA 27a and miRNA150-5p in endometrial cancer patients. Serum was drawn for 36 un-intervened endometrial cancer patients scheduled for hysterectomy and 35 controls. miRNA 27a and miRNA150-5p were measured by real time reverse transcription polymerase chain reaction. Significant overexpression of both miRNA in patients (p < 0.001). At cutoffs 0.2872 & > 1.02, miRNA 27a showed 100% sensitivity, specificity, positive and negative predictive values. miRNA150-5p showed 88.89% sensitivity, 100% specificity, 100% positive and 78.9% negative predictive values. Areas under curve were 1.0 for miRNA 27a, 0.982 for miRNA 150 performing much better than Ca125. miRNA 27a was significantly associated with type I endometroid endometrial cancer. Conclusion: miRNA 27a and miRNA-150-5P can be suggested as promising biomarkers of endometrial cancer possibly part of a miRNA panel for management.

GATA2 regulates the CAD susceptibility gene ADTRP rs6903956 through preferential interaction with the G allele

Myocardial infarction (MI) is a frequent outcome of coronary artery disease (CAD) and the key factor contributing to worldwide disability and death. Genetic factors contribute to the pathogenesis of CAD/MI, and SNP rs6903956 in the ADTRP gene was first found associated with CAD/MI in the Chinese Han population, which was successfully replicated in other cohorts. However, whether rs6903956 is a functional SNP and its risk mechanism to CAD/MI remains unknown. The ADTRP gene-encoded androgen-dependent TFPI regulating protein regulates vascular endothelial cell function, endothelial-monocyte adhesion, and thrombosis. The allele A of rs6903956, in particular, is associated with lower ADTRP mRNA levels in lymphocytes. In the current study, we found that SNP rs6903956 exhibits allelic differences in transcriptional activity by interacting with GATA2. Also, the A allele conferred a greater risk of CAD and MI, lowered transcriptional activity, and GATA2 binding ability as compared to the G allele. Our findings provide details on how rs6903956 regulates the expression of ADTRP and may provide novel insights into CAD pathology and susceptibility.

MicroRNAs: Their Role in Metastasis, Angiogenesis, and the Potential for Biomarker Utility in Bladder Carcinomas

Angiogenesis is the process of generating new capillaries from pre-existing blood vessels with a vital role in tumor growth and metastasis. MicroRNAs (miRNAs) are noncoding RNAs that exert post-transcriptional control of protein regulation. They participate in the development and progression of several cancers including bladder cancer (BLCA). In cancer tissue, changes in microRNA expression exhibit tissue specificity with high levels of stability and detectability. miRNAs are less vulnerable to degradation, making them novel targets for therapeutic approaches. A suitable means of targeting aberrant activated signal transduction pathways in carcinogenesis of BLCA is possibly through altering the expression of key miRNAs that regulate them, exerting a strong effect on signal transduction. Precaution must be taken, as the complexity of miRNA regulation might result in targeting several downstream tumor suppressors or oncogenes, enhancing the effect further. Since exosomes contain both mRNA and miRNA, they could therefore possibly be more effective in targeting a recipient cell if they deliver a specific miRNA to modify the recipient cell protein production and gene expression. In this review, we discuss the molecules that have been shown to play a significant role in BLCA tumor development. We also discuss the roles of various miRNAs in BLCA angiogenesis and metastasis. Advances in the management of metastatic BLCA have been limited; miRNA mimics and molecules targeted at miRNAs (anti-miRs) as well as exosomes could serve as therapeutic modalities or as diagnostic biomarkers.

MicroRNAs in the Tumor Microenvironment

The tumor microenvironment (TME) is decisive for the eradication or survival of any tumor mass. Moreover, it plays a pivotal role for metastasis and for providing the metastatic niche. The TME offers special physiological conditions and is composed of, for example, surrounding blood vessels, the extracellular matrix (ECM), diverse signaling molecules, exosomes and several cell types including, but not being limited to, infiltrated immune cells, cancer-associated endothelial cells (CAEs), and cancer-associated fibroblasts (CAFs). These cells can additionally and significantly contribute to tumor and metastasis progression, especially also by acting via their own deregulated micro (mi) RNA expression or activity. Thus, miRNAs are essential players in the crosstalk between cancer cells and the TME. MiRNAs are small non-coding (nc) RNAs that typically inhibit translation and stability of messenger (m) RNAs, thus being able to regulate several cell functions including proliferation, migration, differentiation, survival, invasion, and several steps of the metastatic cascade. The dynamic interplay between miRNAs in different cell types or organelles such as exosomes, ECM macromolecules, and the TME plays critical roles in many aspects of cancer development. This chapter aims to give an overview on the multiple contributions of miRNAs as players within the TME, to summarize the role of miRNAs in the crosstalk between different cell populations found within the TME, and to illustrate how they act on tumorigenesis and the behavior of cells in the TME context. Lastly, the potential clinical utility of miRNAs for cancer therapy is discussed.

ADAMTS16 activates latent TGF-β, accentuating fibrosis and dysfunction of the pressure-overloaded heart

AIMS

Cardiac fibrosis is a major cause of heart failure (HF), and mediated by the differentiation of cardiac fibroblasts into myofibroblasts. However, limited tools are available to block cardiac fibrosis. ADAMTS16 is a member of the ADAMTS superfamily of extracellular protease enzymes involved in extracellular matrix (ECM) degradation and remodelling. In this study, we aimed to establish ADAMTS16 as a key regulator of cardiac fibrosis.

METHODS AND RESULTS

Western blot and qRT-PCR analyses demonstrated that ADAMTS16 was significantly up-regulated in mice with transverse aortic constriction (TAC) associated with left ventricular hypertrophy and HF, which was correlated with increased expression of Mmp2, Mmp9, Col1a1, and Col3a1. Overexpression of ADAMTS16 accelerated the AngII-induced activation of cardiac fibroblasts into myofibroblasts. Protein structural analysis and co-immunoprecipitation revealed that ADAMTS16 interacted with the latency-associated peptide (LAP)-transforming growth factor (TGF)-β via a RRFR motif. Overexpression of ADAMTS16 induced the activation of TGF-β in cardiac fibroblasts; however, the effects were blocked by a mutation of the RRFR motif to IIFI, knockdown of Adamts16 expression, or a TGF-β-neutralizing antibody (ΝAb). The RRFR tetrapeptide, but not control IIFI peptide, blocked the interaction between ADAMTS16 and LAP-TGF-β, and accelerated the activation of TGF-β in cardiac fibroblasts. In TAC mice, the RRFR tetrapeptide aggravated cardiac fibrosis and hypertrophy by up-regulation of ECM proteins, activation of TGF-β, and increased SMAD2/SMAD3 signalling, however, the effects were blocked by TGF-β-NAb.

CONCLUSION

ADAMTS16 promotes cardiac fibrosis, cardiac hypertrophy, and HF by facilitating cardiac fibroblasts activation via interacting with and activating LAP-TGF-β signalling. The RRFR motif of ADAMTS16 disrupts the interaction between ADAMTS16 and LAP-TGF-β, activates TGF-β, and aggravated cardiac fibrosis and hypertrophy. This study identifies a novel regulator of TGF-β signalling and cardiac fibrosis, and provides a new target for the development of therapeutic treatment of cardiac fibrosis and HF.

Angiogenic factor AGGF1 acts as a tumor suppressor by modulating p53 post-transcriptional modifications and stability via MDM2

Angiogenesis factors are widely known to promote tumor growth by increasing tumor angiogenesis in the tumor microenvironment, however, little is known whether their intracellular function is involved in tumorigenesis. Here we show that AGGF1 acts as a tumor suppressor by regulating p53 when acting inside tumor cells. AGGF1 antagonizes MDM2 function to inhibit p53 ubiquitination, increases the acetylation, phosphorylation, stability and expression levels of p53, activates transcription of p53 target genes, and regulates cell proliferation, cell cycle, and apoptosis. AGGF1 also interacts with p53 through the FHA domain. Somatic AGGF1 variants in the FHA domain in human tumors, including p.Q467H, p.Y469 N, and p.N483T, inhibit AGGF1 activity on tumor suppression. These results identify a key role for AGGF1 in an AGGF1-MDM2-p53 signaling axis with important functions in tumor suppression, and uncover a novel trans-tumor-suppression mechanism dependent on p53. This study has potential implications in diagnosis and therapies of cancer.

The expression of AGGF1, FOXC2, and E-cadherin in esophageal carcinoma and their clinical significance

Angiogenic factor with G-patch and FHA domain 1 (AGGF1) is a newly initiator of angiogenesis. Forkhead box C2 (FOXC2) that is a member of the winged spiral transcription factor family plays an important role in epithelial-mesenchymal transition (EMT). Epithelial-cadherin (E-cad) that is an adhesion molecule is also involved in EMT. The purpose of this study is to investigate the expression of AGGF1, FOXC2, and E-cad in esophageal squamous cell carcinoma (ESCC) and their clinical significance.Immunohistochemistry was performed to investigate the expression of AGGF1, FOXC2, and E-cad in 170 ESCC specimens and corresponding normal esophageal mucosa tissues. Follow-up data was also collected.The positive rates of AGGF1 and FOXC2 expression were significantly higher in ESCC group when compared with the control group; the positive rate of E-cad expression was significantly lower in ESCC group when compared with the control group. Positive rates of AGGF1, FOXC2, and E-cad expression were significantly associated with grades of differentiation, tumor grades, lymph node metastasis stages, as well as tumor-node-metastasis stages. Kaplan-Meier analysis demonstrated that positive expression of AGGF1 or FOXC2 for ESCC patients had significantly unfavorably overall survival time when compared with patients with negative expression of AGGF1 or FOXC2; and positive expression of E-cad for ESCC patients had significantly longer overall survival time when compared with patients with negative expression of E-cad. Multivariate analysis indicated that AGGF1, FOXC2, and E-cad expression and tumor-node-metastasis stages were postoperative independent prognostic factors for ESCC patients.AGGF1, FOXC2, and E-cad may be considered promising biomarkers of ESCC patients' prognosis.

Angiogenic factor with G patch and FHA domains 1 protects retinal vascular endothelial cells under hyperoxia by inhibiting autophagy

Angiogenic factor with G patch and FHA domains 1 (AGGF1) has strong proangiogenic effects on embryonic vascular development and angiogenesis in disease; however, its role in retinopathy has not been elucidated. Retinopathy of prematurity is a serious retinal disorder of premature infants, which is caused by the arrest of immature retinal vascular growth under hyperoxia. This study aims to investigate the effects of AGGF1 on retinal vascular endothelial cells under hyperoxia and the association with autophagy by using rhesus macaque choroid-retinal endothelial (RF/6A) cells. Western blot analysis and immunofluorescence staining were used to detect the expression of AGGF1 in RF/6A cells. Cell Counting Kit-8, flow cytometry, and transwell and matrigel assays were applied to detect the vitality, apoptosis, migration, and tube formation of RF/6A cells, respectively. Western blot analysis was then used to detect the expression of autophagy markers LC3 and Beclin-1, and mCherry-GFP-LC3 adenovirus was used to detect autophagy flux in RF/6A cells. Under hyperoxia, the expression of AGGF1 in RF/6A cells decreased compared with the control. Cell vitality, migration, and tube formation decreased, and apoptosis of RF/6A cells increased under hyperoxia, and these effects of hyperoxia were attenuated by AGGF1. The protein expressions of LC3 and Beclin-1 increased in RF/6A cells and autophagy flux enhanced under hyperoxia. AGGF1 reduced the expression of LC3 and Beclin-1 as well as the autophagy flux stimulated by hyperoxia. The results clearly showed that exogenous AGGF1 can protect retinal vascular endothelial cells and promote angiogenesis under hyperoxia, in which the expression of AGGF1 was inhibited. Inhibition of autophagy by AGGF1 may be one of the mechanisms involved.

Elevated expression of AGGF1 predicts poor prognosis and promotes the metastasis of colorectal cancer

Background

Angiogenic factor with G-patch and FHA domains 1 (AGGF1) can promote angiogenesis and increasing evidence has highlighted the important roles of AGGF1 in tumorigenesis. However, the differential expression as well as the biological functions of AGGF1 in colorectal cancer (CRC) remain to be established. The purpose of the present study is therefore to identify the effect of AGGF1 on prognosis and metastasis in CRC patients.

Methods

The expression level of AGGF1 in CRC was examined by qPCR, western blot and immunohistochemistry in a tissue microarray containing 236 CRC specimens and paired normal mucosae. And the effect of AGGF1 on CRC cell malignance was investigated in our established stable AGGF1 upregulated and knockdown CRC cell lines.

Results

The expression level of AGGF1 in CRC tissue was not significantly different to that in adjacent normal mucosa at the mRNA level. However, at the protein level, AGGF1 expression in CRC tissues was significantly higher than in paired normal mucosa, which showed a clear association with TNM stage, AJCC stage, vascular invasion, and differentiation. Further, we revealed an apparent correlation between AGGF1 expression and poorer disease-free survival and overall survival of CRC patients. In addition, we discovered that AGGF1 significantly promoted CRC cell wound healing, migration, and invasion in vitro and distant metastasis in vivo.

Conclusions

Our study demonstrates the aberrant overexpression of AGGF1 in CRC and provides a basis on which to explore the application of AGGF1 as a potential therapeutic target for CRC patients, especially for CRC patients with distant metastasis.

CircNR3C1 inhibits proliferation of bladder cancer cells by sponging miR-27a-3p and downregulating cyclin D1 expression

Accumulating evidences suggest that circular RNAs play vital roles in human cancers. Previously, we found that circHIPK3 suppressed invasion of bladder cancer cells via sponging miR-558 and downregulating heparanase expression. In this study, we discovered that a circular RNA derived from NR3C1 (circNR3C1) was downregulated in bladder cancer tissues and cell lines according to RNA-Seq data and qRT-PCR analysis. Functionally, we found that overexpression of circNR3C1 could significantly inhibit cell cycle progression and proliferation of bladder cancer cells in vitro, as well as suppress tumor growth in vivo. Mechanistically, we demonstrated that circNR3C1 possessed four targeting sites of miR-27a-3p and could effectively sponge miR-27a-3p to suppress the expression of cyclin D1. Furthermore, we revealed that miR-27a-3p functioned as an oncogene through interacting with 5'UTR of cyclin D1 to enhance its expression, which led to promote cell cycle progression and proliferation in bladder cancer cells. Conclusively, our findings further confirm the hypothesis that circRNAs function as "microRNA sponges", and our data suggest that circNR3C1 and miR-27a-3p would be potential therapeutic targets for bladder cancer treatment.

MiR-27a: A Novel Biomarker and Potential Therapeutic Target in Tumors

MicroRNAs (miRNAs) are endogenous, time sequencing, conserved and small non-coding RNA molecules (19-25 bp long) that regulate gene expression at the post-transcriptional level by binding to the partial sequence homology of the 3'-untranslated region of target messenger (m)RNA. The miRNA-27 family consists of miR-27a and miR-27b, which are transcribed from different chromosomes and different in nucleotide at the 3' end. It has been reported that miR-27a was located on chromosome 19 and played a vital role in tumor development. Increasing evidences support a vital role for miR-27a in modulating polymorphisms, tumorigenesis, proliferation, apoptosis, invasion, migration and angiogenesis. Apart from it, miR-27a could affect drug sensitivity, treatment of cancer and patients prognosis. The miR-27a could be an oncogene or a tumor suppressor in several types of cancer, including colon cancer, pancreatic cancer, breast cancer, bladder cancer and hepatocellular carcinoma. In this review, we discuss the role of miR-27a in tumor biology and clinical significance in detail and offer novel insights into molecular targeting therapy for human cancers.

Knockdown of AGGF1 inhibits the invasion and migration of gastric cancer via epithelial-mesenchymal transition through Wnt/β-catenin pathway

Background

Angiogenic factor with G-patch and FHA domain 1 (AGGF1), as a newly identified human angiogenic factor, is overexpressed in some types of malignant tumors and closely associated with patient’s prognosis. However, the mechanisms involved in the regulation of AGGF1 in gastric cancer (GC) still remain unclear.

Methods

In this study, AGGF1 level in GC tissues and cell lines was analyzed by western blot and quantitative real-time polymerase chain reaction (qRT-PCR). After knockdown of AGGF expression by RNA interference in GC cell lines MKN-45 and MGC-803, wound healing and transwell assays were conducted to examine the effects of AGGF1 on migration and invasion. Tumor growth was assessed in a mouse xenograft model in vivo. Furthermore, expression levels of epithelial–mesenchymal transition (EMT) biomarkers and involvement of the Wnt/β-catenin pathway were detected by western blot and qRT-PCR.

Results

Compared to those in normal groups, the protein and mRNA of AGGF1 expression levels were significantly higher both in GC tissues and cell lines (all P < 0.05). Knockdown of AGGF1 dramatically inhibited the invasion and migration of MKN-45 and MGC-803 cells (all P < 0.01) in vitro, and suppressed the tumor growth of nude mice xenograft model in vivo. Western blot revealed alterations in EMT biomarkers, suggesting the role of AGGF1 in EMT. Moreover, we found that downregulated expression of AGGF1 attenuated Wnt/β-catenin related protein expression.

Conclusions

Collectively, knockdown of AGGF1 inhibits the invasion and migration of gastric cancer via epithelial–mesenchymal transition through Wnt/β-catenin pathway.

Electronic supplementary material

The online version of this article (10.1186/s12935-019-0765-6) contains supplementary material, which is available to authorized users.

MEG3, as a Competing Endogenous RNA, Binds with miR-27a to Promote PHLPP2 Protein Translation and Impairs Bladder Cancer Invasion

Muscle-invasive and metastatic bladder cancer have an extremely poor 5-year survival rate of 5%. In comparison, all other bladder cancers (BCs) have a 5-year survival rate of 77%. This striking contrast indicates that one of the therapeutic kernels for bladder cancer is to elucidate the molecular mechanisms underlying its invasiveness and metastasis. In the current study, we demonstrated that maternally expressed gene 3 (MEG3) is significantly downregulated in human invasive bladder cancers in comparison to non-invasive bladder cancers, and that ectopic expression of MEG3 dramatically inhibits the invasiveness of human bladder cancer cells. Consistently, ectopic expression of MEG3 also attenuates metastatic ability of T24T cells, a cell line derived from T24 cells, in the lungs of nude mice. Our mechanistic studies reveal that MEG3, as a ceRNA, inhibits the invasiveness of human bladder cancer cells via negative regulation of c-Myc by competing with PHLPP2 mRNA for miR-27a. These findings not only provide a novel insight into understanding the mechanisms behind the MEG3 inhibition of bladder cancer cell invasion, but also reveal the potential for use of MEG3 as a tool for the prevention and therapy of invasive bladder cancer.

[ole of AGGF1 in DNA damage repair and modulating chemotherapy resistance in human colon cancer cells in vitro]

OBJECTIVE

To investigate the role of AGGF1 in DNA damage repair and modulating chemotherapy resistance in human colon cancer cells.

METHODS

Cisplatin-induced human colon cancer HCT116 cells transfected with AGGF1 siRNA and siNC via Lipofectamine 2000 were examined for AGGF1, γH2AX and pNBS1 expressions using Western blotting. Immunofluorescence analysis was used to detect the recruitment of phosphorylated γH2AX and AGGF1 at the site of cisplatin-induced double-strand DNA breaks, and MTS method was used to investigate the proliferation of the damaged cells. Immunohistochemical method was used to detect the expression level of AGGF1 in human colon cancer and adjacent normal tissues.

RESULTS

Western blotting showed that AGGF1 expression was significantly down-regulated in HCT116 cells after cisplatin exposure, and transfection withAGGF1 siRNAobviously inhibited the expression of phosphorylated γH2AX and NBS1. Immunofluorescence assay showed the co-localization of AGGF1 and γH2AX. Down-regulation of AGGF1 mediated by siRNA obviously increased the chemosensitivity of the cells (P < 0.01). In the clinical specimens, AGGF1 was found to be overexpressed in colon cancer tissues as compared with the adjacent normal tissues (P < 0.01), suggesting its association with the malignant phenotype of the tumor.

CONCLUSIONS

Down-regulation of AGGF1 inhibits DNA damage repair and increases the chemosensitivity in colon cancer cells possibly in relation with the suppressed phosphorylation of NBS1.

MicroRNAs in Smoking-Related Carcinogenesis: Biomarkers, Functions, and Therapy

Long-term heavy cigarette smoking is a well-known high-risk factor for carcinogenesis in various organs such as the head and neck, lungs, and urinary bladder. Furthermore, cigarette smoking can systemically accelerate aging, and as the result, promoting carcinogenesis via changing the host microenvironment. Various inflammatory factors, hormones, and chemical mediators induced by smoking mediate carcinoma-related molecules and induce carcinogenesis. MicroRNAs (miRNAs) are a family of short noncoding RNA molecules that bind to mRNAs and inhibit their expression. Cigarette smoke induces the expression of various miRNAs, many of which are known to function in the post-transcriptional silencing of anticancer molecules, thereby leading to smoking-induced carcinogenesis. Analysis of expression profiles of smoking-induced miRNAs can help identify biomarkers for the diagnosis and prognosis of smoking-related cancers and prediction of therapeutic responses, as well as revealing promising therapeutic targets. Here, we introduce the most recent and useful findings of miRNA analyses focused on lung cancer and urinary bladder cancer, which are strongly associated with cigarette smoking, and discuss the utility of miRNAs as clinical biomarkers.

Angiotensin II increases angiogenesis by NF-κB-mediated transcriptional activation of angiogenic factor AGGF1

Angiogenic factor with G-patch and FHA domains 1 (AGGF1) is involved in vascular development, angiogenesis, specification of hemangioblasts, and differentiation of veins. When mutated, however, it causes Klippel-Trenaunay syndrome, a vascular disorder. In this study, we show that angiotensin II (AngII)-the major effector of the renin-angiotensin system and one of the most important regulators of the cardiovascular system-induces the expression of AGGF1 through NF-κB, and that AGGF1 plays a key role in AngII-induced angiogenesis. AngII significantly up-regulated the levels of AGGF1 mRNA and protein in HUVECs at concentrations of 10-40 μg/ml but not >60 μg/ml. AngII type 1 receptor (AT1R) inhibitor losartan inhibited AngII-induced up-regulation of AGGF1, whereas AT2R inhibitor PD123319 further increased AngII-induced up-regulation of AGGF1. Up-regulation of AGGF1 by AngII was blocked by NF-κB inhibitors, and p65 binds directly to a binding site at the promoter/regulatory region of AGGF1 and transcriptionally activates AGGF1 expression. AngII-induced endothelial tube formation was blocked by small interfering RNAs (siRNAs) for RELA (RELA proto-oncogene, NF-κB subunit)/p65 or AGGF1, and the effect of RELA siRNA was rescued by AGGF1. AngII-induced angiogenesis from aortic rings was severely impaired in Aggf1^+/- mice, and the effect was restored by AGGF1. These data suggest that AngII acts as a critical regulator of AGGF1 expression through NF-κB, and that AGGF1 plays a key role in AngII-induced angiogenesis.-Si, W., Xie, W., Deng, W., Xiao, Y., Karnik, S. S., Xu, C., Chen, Q., Wang, Q. K. Angiotensin II increases angiogenesis by NF-κB-mediated transcriptional activation of angiogenic factor AGGF1.

The Effect of MCM3AP-AS1/miR-211/KLF5/AGGF1 Axis Regulating Glioblastoma Angiogenesis

Glioblastoma (GBM) is the most aggressive and malignant primary tumor. Angiogenesis plays a critical role in the progression of GBM. Previous studies have indicated that long non-coding RNAs (lncRNAs) are abnormally expressed in various cancers and participate in the regulation of the malignant behaviors of tumors. The present study demonstrated that lncRNA antisense 1 to Micro-chromosome maintenance protein 3-associated protein (MCM3AP-AS1) was upregulated whereas miR-211 was downregulated in glioma-associated endothelial cells (GECs). Knockdown of MCM3AP-AS1 suppressed the cell viability, migration, and tube formation of GECs and played a role in inhibiting angiogenesis of GBM in vitro. Furthermore, knockdown of MCM3AP-AS1 increased the expression of miR-211. Luciferase reporter assay implicated that miR-211 targeted KLF5 3'-UTR and consequently inhibited KLF5 expression. Besides, in this study we found that MCM3AP-AS1 knockdown decreased KLF5 and AGGF1 expression by upregulating miR-211. In addition, KLF5 was associated with the promoter region of AGGF1. Knockdown of KLF5 decreased AGGF1 expression by transcriptional repression, and also inhibited the activation of PI3K/AKT and ERK1/2 signaling pathways. Overall, this study reveals that MCM3AP-AS1/miR-211/KLF5/AGGF1 axis plays a prominent role in the regulation of GBM angiogenesis and also serves as new therapeutic target for the anti-angiogenic therapy of glioma.

High expression of angiogenic factor AGGF1 is an independent prognostic factor for hepatocellular carcinoma

Background

Angiogenesis plays a critical role in tumor growth and metastasis. Angiogenic factor with G patch and FHA domains 1 (AGGF1) has been recently identified as a novel initiator of angiogenesis. However, the function and the prognostic values of AGGF1 in hepatocellular carcinoma remain poorly understood. Our aim is to provide more information to assist design the angiogenesis therapy that targets AGGF1 in HCC.

Results

AGGF1-positive frequency in HCC tissues was significantly higher than in peritumor tissues. The high expression of AGGF1 expression in HCC tissue was well associated with the increased expression of VEGF and the high microvessel density (MVD). AGGF1 expression predicts a poor prognosis and AGGF1 was an independent prognostic factor for DFS.

Methods

The expression levels of AGGF1, vascular endothelial growth factor (VEGF) and microvessel density (MVD) were identified by immunohistochemistry in 79 HCC tumor tissues and 24 corresponding peritumor tissues. The expression level of AGGF1 and MVD were quantified by counting the positively stained endothelial cells in the HCC and the peritumor tissue on the immunohistochemically stained tissue slides. The prognostic value of AGGF1 was evaluated by survival analysis.

Conclusions

Our study shows that AGGF1 is identified as the independent prognostic factor for the disease-free survival (DFS) of patients after the surgical resection. contribute to tumor angiogenesis in HCC, which indicates that AGGF1 may be a new potential therapeutic target for anti-angiogenesis treatment for patients with HCC.

miR-27a induced by colon cancer cells in HLECs promotes lymphangiogenesis by targeting SMAD4

Aim

Metastasis of tumor cells occurs through lymphatic vessels, blood vessels and transcoelomic spreading. Growing evidence from in vivo and in vitro studies has indicated that tumor lymphangiogenesis facilitates metastasis. However, the regulation of lymphangiogenesis in colon cancer remains unclear. The aims of this study were to identify key miRNAs in colon cancer lymphangiogenesis and to investigate its target and mechanism.

Methods

miRNA microarray analysis was conducted to identify miRNAs in human lymphatic endothelial cells (HLECs) that were regulated by co-cultured human colon cancer cells. Gain- and loss-of-function studies were performed to determine the function of miR-27a, a top hint, on lymphangiogenesis and migration in HLECs. Furthermore, bioinformatics prediction and experimental validation were performed to identify miR-27a target genes in lymphangiogenesis.

Results

We found that expression of miR-27a in HLECs was induced by co-culturing with colon cancer cells. Over-expression of miR-27a in HLECs enhanced lymphatic tube formation and migration, whereas inhibition of miR-27a reduced lymphatic tube formation and migration. Luciferase reporter assays showed that miR-27a directly targeted SMAD4, a pivotal component of the TGF-β pathway. In addition, gain-of-function and loss-of-function experiments showed that SMAD4 negatively regulated the length of lymphatic vessels formed by HLECs and migration.

Conclusions

Our data indicated that colon cancer cell induced the expression of miR-27a in HLECs, which promoted lymphangiogenesis by targeting SMAD4. Our finding implicated miR-27a as a potential target for new anticancer therapies in colon cancer.

Haploinsufficiency of Klippel-Trenaunay syndrome gene Aggf1 inhibits developmental and pathological angiogenesis by inactivating PI3K and AKT and disrupts vascular integrity by activating VE-cadherin

Aggf1 is the first gene identified for Klippel-Trenaunay syndrome (KTS), and encodes an angiogenic factor. However, the in vivo roles of Aggf1 are incompletely defined. Here we demonstrate that Aggf1 is essential for both physiological angiogenesis and pathological tumour angiogenesis in vivo. Two lines of Aggf1 knockout (KO) mice showed a particularly severe phenotype as no homozygous embryos were observed and heterozygous mice also showed embryonic lethality (haploinsufficient lethality) observed only for Vegfa and Dll4. Aggf1+/- KO caused defective angiogenesis in yolk sacs and embryos. Survived adult heterozygous mice exhibit frequent haemorrhages and increased vascular permeability due to increased phosphorylation and reduced membrane localization of VE-cadherin. AGGF1 inhibits VE-cadherin phosphorylation, increases plasma membrane VE-cadherin in ECs and in mice, blocks vascular permeability induced by ischaemia-reperfusion (IR), restores depressed cardiac function and contraction, reduces infarct sizes, cardiac fibrosis and necrosis, haemorrhages, edema, and macrophage density associated with IR. Mechanistically, AGGF1 promotes angiogenesis by activating catalytic p110α subunit and p85α regulatory subunit of PI3K, leading to activation of AKT, GSK3β and p70S6K. AKT activation is significantly reduced in heterozygous KO mice and isolated KO ECs, which can be rescued by exogenous AGGF1. ECs from KO mice show reduced capillary angiogenesis, which is rescued by AGGF1 and AKT. Tumour growth/angiogenesis is reduced in heterozygous mice, which was associated with reduced activation of p110α, p85α and AKT. Together with recent identification of somatic mutations in p110α (encoded by PIK3CA), our data establish a potential mechanistic link between AGGF1 and PIK3CA, the two genes identified for KTS.

Targeting AGGF1 (angiogenic factor with G patch and FHA domains 1) for Blocking Neointimal Formation After Vascular Injury

Background

Despite recent improvements in angioplasty and placement of drug‐eluting stents in treatment of atherosclerosis, restenosis and in‐stent thrombosis impede treatment efficacy and cause numerous deaths. Research efforts are needed to identify new molecular targets for blocking restenosis. We aim to establish angiogenic factor AGGF1 (angiogenic factor with G patch and FHA domains 1) as a novel target for blocking neointimal formation and restenosis after vascular injury.

Methods and Results

AGGF1 shows strong expression in carotid arteries; however, its expression is markedly decreased in arteries after vascular injury. AGGF1^+/− mice show increased neointimal formation accompanied with increased proliferation of vascular smooth muscle cells (VSMCs) in carotid arteries after vascular injury. Importantly, AGGF1 protein therapy blocks neointimal formation after vascular injury by inhibiting the proliferation and promoting phenotypic switching of VSMCs to the contractile phenotype in mice in vivo. In vitro, AGGF1 significantly inhibits VSMCs proliferation and decreases the cell numbers at the S phase. AGGF1 also blocks platelet‐derived growth factor‐BB–induced proliferation, migration of VSMCs, increases expression of cyclin D, and decreases expression of p21 and p27. AGGF1 inhibits phenotypic switching of VSMCs to the synthetic phenotype by countering the inhibitory effect of platelet‐derived growth factor‐BB on SRF expression and the formation of the myocardin/SRF/CArG‐box complex involved in activation of VSMCs markers. Finally, we show that AGGF1 inhibits platelet‐derived growth factor‐BB–induced phosphorylation of MEK1/2, ERK1/2, and Elk phosphorylation involved in the phenotypic switching of VSMCs, and that overexpression of Elk abolishes the effect of AGGF1.

Conclusions

AGGF1 protein therapy is effective in blocking neointimal formation after vascular injury by regulating a novel AGGF1‐MEK1/2‐ERK1/2‐Elk‐myocardin‐SRF/p27 signaling pathway.

Androgen inhibits key atherosclerotic processes by directly activating ADTRP transcription

Low androgen levels are associated with an increased risk of coronary artery disease (CAD), thrombosis and myocardial infarction (MI), suggesting that androgen has a protective role. However, little is known about the underlying molecular mechanism. Our genome-wide association study identified the ADTRP gene encoding the androgen-dependent TFPI regulating protein as a susceptibility gene for CAD and MI. The expression level of ADTRP was regulated by androgen, but the molecular mechanism is unknown. In this study, we identified the molecular mechanism by which androgen regulates ADTRP expression and tested the hypothesis that androgen plays a protective role in cardiovascular disease by activating ADTRP expression. Luciferase assays with an ADTRP promoter luciferase reporter revealed that androgen regulated ADTRP transcription in a dose- and time-dependent manner, and the effect was abolished by three different androgen inhibitors, including pyrvinium pamoate, bicalutamide, and cyproterone acetate. Chromatin-immunoprecipitation showed that the androgen receptor bound to a half androgen response element (ARE, TGTTCT) located at +324bp from the ADTRP transcription start site. The ARE is required for concentration-dependent transcriptional activation of ADTRP. HL-60 monocyte adhesion to EAhy926 endothelial cells (ECs) and transmigration across the EC layer, the two processes critical to development of CAD and MI, were inhibited by androgen, but the effect was rescued by ADTRP siRNA and exacerbated by overexpression of ADTRP and its downstream genes PIK3R3 and MIA3. These data suggest that one molecular mechanism by which androgen confers protection against CAD is stimulation of ADTRP expression.

Identification of a molecular signaling gene-gene regulatory network between GWAS susceptibility genes ADTRP and MIA3/TANGO1 for coronary artery disease

Coronary artery disease (CAD) is the leading cause of death worldwide. GWAS have identified >50 genomic loci for CAD, including ADTRP and MIA3/TANGO1. However, it is important to determine whether the GWAS genes form a molecular network. In this study, we have uncovered a novel molecular network between ADTRP and MIA3/TANGO1 for the pathogenesis of CAD. We showed that knockdown of ADTRP expression markedly down-regulated expression of MIA3/TANGO1. Mechanistically, ADTRP positively regulates expression of PIK3R3 encoding the regulatory subunit 3 of PI3K, which leads to activation of AKT, resulting in up-regulation of MIA3/TANGO1. Both ADTRP and MIA3/TANGO1 are involved in endothelial cell (EC) functions relevant to atherosclerosis. Knockdown of ADTRP expression by siRNA promoted oxidized-LDL-mediated monocyte adhesion to ECs and transendothelial migration of monocytes, inhibited EC proliferation and migration, and increased apoptosis, which was reversed by expression of constitutively active AKT1 and MIA3/TANGO1 overexpression, while the over-expression of ADTRP in ECs blunted these processes. Knockdown of MIA3/TANGO1 expression also promoted monocyte adhesion to ECs and transendothelial migration of monocytes, and vice versa for overexpression of MIA3/TANGO1. We found that ADTRP negatively regulates the levels of collagen VII and ApoB in HepG2 and endothelial cells, which are downstream regulatory targets of MIA3/TANGOI. In conclusion, we have uncovered a novel molecular signaling pathway for the pathogenesis of CAD, which involves a novel gene-gene regulatory network. We show that ADTRP positively regulates PIK3R3 expression, which leads to activation of AKT and up-regulation of MIA3/TANGO1, thereby regulating endothelial cell functions directly relevant to atherosclerosis.

High Expression of Angiogenic Factor with G-Patch and FHA Domain1 (AGGF1) Predicts Poor Prognosis in Gastric Cancer

Background

Angiogenic factor with G-patch and FHA domain1 (AGGF1 or VG5Q) is a newly identified human angiogenic factor. The aim of this study was to explore AGGF1 expression level in gastric cancer and detect its correlation with the prognosis.

Material/Methods

Immunohistochemistry was performed to detect AGGF1 level in gastric cancer and its adjacent noncancerous samples of 198 cases, and the relationships among the expression levels of AGGF1, vascular endothelial growth factor (VEGF), and prognosis were analyzed.

Results

Expression of AGGF1 in gastric cancer samples was significantly higher than that in adjacent noncancerous samples (P<0.001). The overall survival rate (OS) of patients with high AGGF1 expression was significantly lower than that of patients with low AGGF1 expression (P=0.000). The Cox model analysis demonstrated that expression of AGGF1 was an independent biomarker for prediction of patients’ survival in gastric cancer.

Conclusions

High expression of AGGF1 predicts poor prognosis in gastric cancer patients. AGGF1 can be used as an independent factor to predict postoperative survival of patients with gastric cancer.

Up-regulation of miR-95-3p in hepatocellular carcinoma promotes tumorigenesis by targeting p21 expression

Hepatocellular carcinoma (HCC) is one of the most common malignant cancers. To elucidate new regulatory mechanisms for heptocarcinogenesis, we investigated the regulation of p21, a cyclin-dependent kinase (CDK) inhibitor encoded by CDKN1A, in HCC. The expression level of p21 is decreased with the progression of HCC. Luciferase assays with a luciferase-p21-3' UTR reporter and its serial deletions identified a 15-bp repressor element at the 3'-UTR of CDKN1A, which contains a binding site for miR-95-3p. Mutation of the binding site eliminated the regulatory effect of miR-95-3p on p21 expression. Posttranscriptional regulation of p21 expression by miR-95-3p is mainly on the protein level (suppression of translation). Overexpression of miR-95-3p in two different HCC cell lines, HepG2 and SMMC7721, significantly promoted cell proliferation, cell cycle progression and cell migration, whereas a miR-95-3p specific inhibitor decreased cell proliferation, cell cycle progression and cell migration. The effects of miR-95-3p on cellular functions were rescued by overexpression of p21. Overexpression of miR-95-3p promoted cell proliferation and tumor growth in HCC xenograft mouse models. Expression of miR-95-3p was significantly higher in HCC samples than in adjacent non-cancerous samples. These results demonstrate that miR-95-3p is a potential new marker for HCC and regulates hepatocarcinogenesis by directly targeting CDKN1A/p21 expression.

Angiogenic Factor AGGF1 Activates Autophagy with an Essential Role in Therapeutic Angiogenesis for Heart Disease

AGGF1 is an angiogenic factor with therapeutic potential to treat coronary artery disease (CAD) and myocardial infarction (MI). However, the underlying mechanism for AGGF1-mediated therapeutic angiogenesis is unknown. Here, we show for the first time that AGGF1 activates autophagy, a housekeeping catabolic cellular process, in endothelial cells (ECs), HL1, H9C2, and vascular smooth muscle cells. Studies with Atg5 small interfering RNA (siRNA) and the autophagy inhibitors bafilomycin A1 (Baf) and chloroquine demonstrate that autophagy is required for AGGF1-mediated EC proliferation, migration, capillary tube formation, and aortic ring-based angiogenesis. Aggf1^+/- knockout (KO) mice show reduced autophagy, which was associated with inhibition of angiogenesis, larger infarct areas, and contractile dysfunction after MI. Protein therapy with AGGF1 leads to robust recovery of myocardial function and contraction with increased survival, increased ejection fraction, reduction of infarct areas, and inhibition of cardiac apoptosis and fibrosis by promoting therapeutic angiogenesis in mice with MI. Inhibition of autophagy in mice by bafilomycin A1 or in Becn1^+/- and Atg5 KO mice eliminates AGGF1-mediated angiogenesis and therapeutic actions, indicating that autophagy acts upstream of and is essential for angiogenesis. Mechanistically, AGGF1 initiates autophagy by activating JNK, which leads to activation of Vps34 lipid kinase and the assembly of Becn1-Vps34-Atg14 complex involved in the initiation of autophagy. Our data demonstrate that (1) autophagy is essential for effective therapeutic angiogenesis to treat CAD and MI; (2) AGGF1 is critical to induction of autophagy; and (3) AGGF1 is a novel agent for treatment of CAD and MI. Our data suggest that maintaining or increasing autophagy is a highly innovative strategy to robustly boost the efficacy of therapeutic angiogenesis.

Treatment with the angiogenic factor AGGF1 dramatically improves survival and cardiac function in mouse models for coronary artery disease and myocardial infarction by activating autophagy and angiogenesis.

Coronary artery disease is the number one killer disease worldwide. Recently, therapeutic angiogenesis has been proposed as an attractive new strategy for treating this and other ischemic diseases. This study establishes the angiogenic factor AGGF1 as a novel target and agent that can successfully treat coronary artery disease and acute myocardial infarction and dramatically improve survival and cardiac function in mouse models. We present the unexpected finding that AGGF1 has these effects via activating autophagy, and that autophagy is essential for therapeutic angiogenesis in animals. We find that AGGF1 is a novel master regulator of autophagy not only in endothelial cells but also in all other cell types examined in the study. Mechanistically, AGGF1 activates autophagy by activating JNK, which leads to activation of the Vps34 lipid kinase and assembly of the Becn1-Vps34-Atg14 complex involved in the initiation of autophagy. The study thus provides a link connecting the therapeutic angiogenesis and autophagy pathways in heart disease.

MicroRNA: a connecting road between apoptosis and cholesterol metabolism

Resistance to apoptosis leads to tumorigenesis and failure of anti-cancer therapy. Recent studies also highlight abrogated lipid/cholesterol metabolism as one of the root causes of cancer that can lead to metastatic transformations. Cancer cells are dependent on tremendous supply of cellular cholesterol for the formation of new membranes and continuation of cell signaling. Cholesterol homeostasis network tightly regulates this metabolic need of cancer cells on cholesterol and other lipids. Genetic landscape is also shared between apoptosis and cholesterol metabolism. MicroRNAs (miRNAs) are the new fine tuners of signaling pathways and cellular processes and are known for their ability to post-transcriptionally repress gene expression in a targeted manner. This review summarizes the current knowledge about the cross talk between apoptosis and cholesterol metabolism via miRNAs. In addition, we also emphasize herein recent therapeutic modulations of specific miRNAs and their promising potential for the treatment of deadly diseases including cancer and cholesterol related pathologies. Understanding of the impact of miRNA-based regulation of apoptosis and metabolic processes is still at its dawn and needs further research for the development of future miRNA-based therapies. As both these physiological processes affect cellular homeostasis, we believe that this comprehensive summary of miRNAs modulating both apoptosis and cholesterol metabolism will open uncharted territory for scientific exploration and will provide the foundation for discovering novel drug targets for cancer and metabolic diseases.

αB-Crystallin Interacts with Nav1.5 and Regulates Ubiquitination and Internalization of Cell Surface Nav1.5

Nav1.5, the pore-forming α subunit of the cardiac voltage-gated Na(+) channel complex, is required for the initiation and propagation of the cardiac action potential. Mutations in Nav1.5 cause cardiac arrhythmias and sudden death. The cardiac Na(+) channel functions as a protein complex; however, its complete components remain to be fully elucidated. A yeast two-hybrid screen identified a new candidate Nav1.5-interacting protein, αB-crystallin. GST pull-down, co-immunoprecipitation, and immunostaining analyses validated the interaction between Nav1.5 and αB-crystallin. Whole-cell patch clamping showed that overexpression of αB-crystallin significantly increased peak sodium current (INa) density, and the underlying molecular mechanism is the increased cell surface expression level of Nav1.5 via reduced internalization of cell surface Nav1.5 and ubiquitination of Nav1.5. Knock-out of αB-crystallin expression significantly decreased the cell surface expression level of Nav1.5. Co-immunoprecipitation analysis showed that αB-crystallin interacted with Nedd4-2; however, a catalytically inactive Nedd4-2-C801S mutant impaired the interaction and abolished the up-regulation of INa by αB-crystallin. Nav1.5 mutation V1980A at the interaction site for Nedd4-2 eliminated the effect of αB-crystallin on reduction of Nav1.5 ubiquitination and increases of INa density. Two disease-causing mutations in αB-crystallin, R109H and R151X (nonsense mutation), eliminated the effect of αB-crystallin on INa This study identifies αB-crystallin as a new binding partner for Nav1.5. αB-Crystallin interacts with Nav1.5 and increases INa by modulating the expression level and internalization of cell surface Nav1.5 and ubiquitination of Nav1.5, which requires the protein-protein interactions between αB-crystallin and Nav1.5 and between αB-crystallin and functionally active Nedd4-2.

Molecular Basis of Gene-Gene Interaction: Cyclic Cross-Regulation of Gene Expression and Post-GWAS Gene-Gene Interaction Involved in Atrial Fibrillation

Atrial fibrillation (AF) is the most common cardiac arrhythmia at the clinic. Recent GWAS identified several variants associated with AF, but they account for <10% of heritability. Gene-gene interaction is assumed to account for a significant portion of missing heritability. Among GWAS loci for AF, only three were replicated in the Chinese Han population, including SNP rs2106261 (G/A substitution) in ZFHX3, rs2200733 (C/T substitution) near PITX2c, and rs3807989 (A/G substitution) in CAV1. Thus, we analyzed the interaction among these three AF loci. We demonstrated significant interaction between rs2106261 and rs2200733 in three independent populations and combined population with 2,020 cases/5,315 controls. Compared to non-risk genotype GGCC, two-locus risk genotype AATT showed the highest odds ratio in three independent populations and the combined population (OR=5.36 (95% CI 3.87-7.43), P=8.00×10-24). The OR of 5.36 for AATT was significantly higher than the combined OR of 3.31 for both GGTT and AACC, suggesting a synergistic interaction between rs2106261 and rs2200733. Relative excess risk due to interaction (RERI) analysis also revealed significant interaction between rs2106261 and rs2200733 when exposed two copies of risk alleles (RERI=2.87, P<1.00×10-4) or exposed to one additional copy of risk allele (RERI=1.29, P<1.00×10-4). The INTERSNP program identified significant genotypic interaction between rs2106261 and rs2200733 under an additive by additive model (OR=0.85, 95% CI: 0.74-0.97, P=0.02). Mechanistically, PITX2c negatively regulates expression of miR-1, which negatively regulates expression of ZFHX3, resulting in a positive regulation of ZFHX3 by PITX2c; ZFHX3 positively regulates expression of PITX2C, resulting in a cyclic loop of cross-regulation between ZFHX3 and PITX2c. Both ZFHX3 and PITX2c regulate expression of NPPA, TBX5 and NKX2.5. These results suggest that cyclic cross-regulation of gene expression is a molecular basis for gene-gene interactions involved in genetics of complex disease traits.

The role of miRNAs in stress-responsive hepatic stellate cells during liver fibrosis

The progression of liver fibrosis and cirrhosis is associated with the persistence of an injury causing agent, leading to changes in the extracellular environment and a disruption of the cellular homeostasis of liver resident cells. Recruitment of inflammatory cells, apoptosis of hepatocytes, and changes in liver microvasculature are some examples of changing cellular environment that lead to the induction of stress responses in nearby cells. During liver fibrosis, the major stresses include hypoxia, oxidative stress, and endoplasmic reticulum stress. When hepatic stellate cells (HSCs) are subjected to such stress, they modulate fibrosis progression by induction of their activation toward a myofibroblastic phenotype, or by undergoing apoptosis, and thus helping fibrosis resolution. It is widely accepted that microRNAs are import regulators of gene expression, both during normal cellular homeostasis, as well as in pathologic conditions. MicroRNAs are short RNA sequences that regulate the gene expression by mRNA destabilization and inhibition of mRNA translation. Specific microRNAs have been identified to play a role in the activation process of HSCs on the one hand and in stress-responsive pathways on the other hand in other cell types (Table 2). However, so far there are no reports for the involvement of miRNAs in the different stress responses linked to HSC activation. Here, we review briefly the major stress response pathways and propose several miRNAs to be regulated by these stress responsive pathways in activating HSCs, and discuss their potential specific pro-or anti-fibrotic characteristics.

MicroRNAs in tumor angiogenesis

As it is necessary for tumor growth, angiogenesis has been an attractive target for drug therapy. Accumulating evidences indicate that microRNAs (miRNAs), which are short non-coding RNAs, delicately regulate the angiogenic signals through targeting angiogenic factors and protein kinases. They can modulate pro-angiogenic signals induced by vascular endothelial growth factor (VEGF) and anti-angiogenic signals induced by thrombospondin-1 (TSP-1), and therefore promote or inhibit tumor angiogenesis. Receptor tyrosine kinases (RTKs) and hypoxia inducible factor (HIF) are also targeted by miRNAs. Moreover, miRNAs crosstalk with reactive oxygen species (ROS) influencing tumor angiogenesis. It is critical to understand the role of miRNAs in tumor angiogenesis due to their therapeutic potential to improve outcome for cancer patients. The following review discusses the current state of knowledge related to tumor angiogenesis-regulatory miRNAs and their targets.

Overexpression of AGGF1 is correlated with angiogenesis and poor prognosis of hepatocellular carcinoma

Angiogenic factor with G-patch and FHA domains 1 (AGGF1) is a factor implicating in vascular differentiation and angiogenesis. Several lines of evidence indicate that aberrant expression of AGGF1 is associated with tumor initiation and progression. The aim of this study was to investigate the expression and prognostic value of AGGF1 in hepatocellular carcinoma (HCC), as well as its relationship with clinicopathological factors and tumor angiogenesis. Immunohistochemistry was performed to evaluate the expression of AGGF1 in HCC and paracarcinomatous tissues collected from 70 patients. Vascular endothelial growth factor (VEGF) and CD34 expression levels were examined in the 70 HCC tissues. Prognostic significance of tumoral AGGF1 expression was determined. Notably, AGGF1 expression was significantly higher in HCC than in surrounding non-tumor tissues (65.7 vs. 25.7 %; P < 0.001). AGGF1 expression was significantly correlated with tumoral VEGF expression and CD34-positive microvessel density. Moreover, AGGF1 expression was significantly associated with tumor size, tumor capsule, vascular invasion, Edmondson grade, alpha-fetoprotein level, and TNM stage. Kaplan-Meier survival analysis showed that high AGGF1 was correlated with reduced overall survival (OS) rate (P = 0.001) and disease-free survival (DFS) rate (P < 0.001). Multivariate analysis identified AGGF1 as an independent poor prognostic factor of OS and DFS in HCC patients (P = 0.043 and P = 0.010, respectively). Taken together, increased AGGF1 expression is associated with tumor angiogenesis and serves as an independent unfavorable prognostic factor for OS and DFS in HCC. AGGF1 may represent a potential therapeutic target for HCC.

microRNAs in the tumor microenvironment: solving the riddle for a better diagnostics

miRNAs are small noncoding RNAs with gene regulatory functions, frequently dysregulated in human cancers. Specific signatures of differentially expressed miRNAs can be used in the diagnosis of cancer and in some cases harbor prognostic implications. The biology of cancer is dictated not only by cancer cells but also by the surrounding tumor microenvironment. In particular, the role of miRNAs within the tumor microenvironment is emerging as of paramount importance. This review will focus on the current knowledge of the role of miRNAs and both cellular and stromal components of the tumor microenvironment. We will also discuss more recent findings, showing that miRNAs can be found inside of exosomes and mediate the cross-talk between cancer cells and surrounding cells, leading to the discovery of new fascinating molecular mechanisms leading to a better understanding of the cancer 'niche' and how these noncoding RNAs can become very promising diagnostic molecules.

Circulating microRNAs as a fingerprint for endometrial endometrioid adenocarcinoma

BACKGROUND

Endometrial cancer is the most common malignancy of the female genital tract worldwide, and endometrial endometrioid adenocarcinoma (EEC) is the major histological type of endometrial cancer. There is a great need for better markers with high sensitivity and specificity to permit early diagnosis and proper management of EEC. The aim of our study is to identify a miRNA classifier within plasma as a noninvasive biomarker for EEC diagnosis.

METHODS

This study was a retrospective case-control analysis which contained two independent cohorts including 93 participants. First, we screened 375 miRNAs in 29 plasma samples. 9 of the miRNAs were selected to be evaluated their expression by quantitative reverse-transcriptase polymerase chain reaction. A stepwise logistic regression model was then used to establish a new classifier in the validation cohort. Area under the receiver operating characteristic curve was used to evaluate the diagnostic accuracy. Co-expression analysis was used to verify the independence of results.

RESULTS

miR-15b, -27a, and -223 were found to be differentially expressed in the EEC plasma between the two cohorts and had few connections with other miRNAs. The areas under the curve (AUC) were 0.768, 0.813, and 0.768 for miR-15b, -27a, and 223, respectively. miR-27a and CA125 can be combined as a potential non-invasive biomarker for detecting EEC, with the AUC of 0.894.

CONCLUSION

Our study demonstrated three miRNAs, including miR-15b, -27a, and -233 have a good clinical value in EEC diagnosis. The classifier, including miR-27a and CA125, demonstrated a high accuracy in the diagnosis of EEC and might serve as a novel non-invasive biomarker in the future.