Exosome-transmitted ANGPTL1 suppresses angiogenesis in glioblastoma by inhibiting the VEGFA/VEGFR2/Akt/eNOS pathway.

OBJECTIVE: Glioblastoma (GBM) is a highly vascularized malignancy that relies on new vessel generation, and thus targeting angiogenesis has been a promising anti-GBM approach. ANGPTL1 is well-known for its anti-angiogenic property; nevertheless, its role in GBM is yet to be explored. Recently, the crucial role of exosomes (Exos) as intercellular communication mediators has gained prominence in GBM therapy. This work aimed to explore the role of exosomal ANGPTL1 in GBM angiogenesis and its mechanisms. METHODS: Bioinformatic analysis was performed to evaluate ANGPTL expression in GBM. Human GBM cell lines (U87 and U251) and a xenograft mouse model were employed. Exos were isolated from oe-NC- and oe-ANGPTL-transfected bone mesenchymal stem cells and identified. Cell proliferation, migration, and apoptosis were detected. Immunofluorescence, qRT-PCR, western blotting, co-immunoprecipitation, and immunohistochemistry were used to determine the molecular mechanisms underlying exosomal ANGPTL1 against GBM angiogenesis. Besides, tube generation and transmission electron microscope assays were conducted to assess GBM angiogenesis. RESULTS: Low ANGPTL1 expression was observed in GBM tumor tissues and cells. Functionally, e-ANGPTL-Exos inhibited GBM malignant progression and angiogenesis in vitro and in vivo. Mechanically, e-ANGPTL-Exos reduced VEGFA expression and blocked the VEGFR2/Akt/eNOS pathway in GBM cells and tumor tissues. Co-immunoprecipitation revealed a link between ANGPTL1 and VEGFA in GBM cells. Notably, oe-VEGFA abolished the suppressive functions of e-ANGPTL-Exos in GBM progression and angiogenesis and the VEGFR2/Akt/eNOS axis. The VEGFR2 inhibitor, vandetanib, eliminated the promotive effects of oe-VEGFA on GBM angiogenesis with suppressed VEGFR2/Akt/eNOS pathway. CONCLUSIONS: Exosomal ANGPTL1 suppressed GBM angiogenesis by inhibiting the VEGFA/VEGFR2/Akt/eNOS axis.

ANGPTL1, Foxo3a-Sox2, and colorectal cancer metastasis.

In the present commentary, we discuss new observations stating that angiopoietin-like protein 1 (ANGPTL1) attenuates cancer metastasis and stemness through Forkhead box O-3a (Foxo3a)-SRY-related HMG-box-2 (Sox2) axis in colorectal cancer (Clin. Sci. (2022) 136, 657-673, https://doi.org/10.1042/CS20220043). ANGPTL1 has been reported to play a critical role in cancer progression and metastasis. However, the underlying mechanisms remain controversial. Here, we integrate the possible mechanisms for ANGPTL1 inhibiting colorectal cancer liver metastasis and discuss the regulation of ANGPTL1 on the Foxo3a-Sox2 pathway. Although ANGPTL1 showed multifunctional potential, there is still a long way to go for ANGPTL1 to be an effective treatment strategy in the clinic.

Lncrna ANGPTL1-3 and its target microRNA-30a exhibit potency as biomarkers for bortezomib response and prognosis in multiple myeloma patients.

OBJECTIVE: Long non-coding RNA ANGPTL1-3 (lnc-ANGPTL1-3) is previously observed to induce bortezomib resistance via targeting microRNA-30a (miR-30a) in multiple myeloma (MM). Hence, this study aimed to further explore the relationship between lnc-ANGPTL1-3 and miR-30a and their linkage with disease properties and prognosis in bortezomib-treated MM patients. METHODS: Fifty-nine MM patients underwent treatment with the bortezomib-based regimen, and 30 healthy donors were consecutively enrolled. Bone marrow samples were collected from MM patients (before therapy) and healthy donors; then, plasma cells were separated for lnc-ANGPTL1-3 and miR-30a detection by RT-qPCR. Then treatment response, progression-free survival (PFS), and overall survival (OS) of MM patients were assessed. RESULTS: Lnc-ANGPTL1-3 was upregulated while miR-30a was downregulated in MM patients compared to healthy donors (both P < 0.001), then a negative correlation between lnc-ANGPTL1-3 and miR-30a was found in MM patients (P < 0.001) instead of in health donors (P = 0.188). In MM patients, lnc-ANGPTL1-3 correlated with increased t (4;14) (P = 0.033), Del (17p) (P = 0.018), ISS stage (P = 0.020), R-ISS stage (P = 0.025) but not t (14;16) (P = 0.255) or Durie-Salmon stage (P = 0.186); while miR-30a only related to decreased t (14;16) (P = 0.025) and R-ISS stage (P = 0.006). Besides, lnc-ANGPTL1-3 predicted lower complete response (CR) (P = 0.034), poor PFS (P = 0.016) and OS (P = 0.041) but not objective response rate (ORR) (P = 0.128). However, miR-30a forecasted higher CR (P = 0.013), prolonged PFS (P = 0.014), and OS (P = 0.045) but not ORR (P = 0.407). CONCLUSION: Lnc-ANGPTL1-3 negative correlates with miR-30a, which links with key cytogenetic features, ISS/R-ISS stage, and prognosis in MM patients who underwent treatment of bortezomib-based regimen.

ANGPTL1 attenuates cancer migration, invasion, and stemness through regulating FOXO3a-mediated SOX2 expression in colorectal cancer.

Angiopoietin-like protein 1 (ANGPTL1) is a member of the ANGPTL family that suppresses angiogenesis, cancer invasion, metastasis, and cancer progression. ANGPTL1 is down-regulated in various cancers including colorectal cancer (CRC); however, the effects and mechanisms of ANGPTL1 on liver metastasis and cancer stemness in CRC are poorly understood. In the present study, we identified that ANGPTL1 was down-regulated in CRC and inversely correlated with metastasis and poor clinical outcomes in CRC patients form the ONCOMINE database and Human Tissue Microarray staining. ANGPTL1 significantly suppressed the migration/invasion abilities, the expression of cancer stem cell (CSC) markers, and sphere formation by enhancing FOXO3a expression, which contributed to the reduction of stem cell transcription factor SOX2 expression in CRC cells. Consistently, overexpression of ANGPTL1 reduced liver metastasis, tumor growth, and tumorigenicity in tumor-bearing mice. ANGPTL1 expression was negatively correlated with CSC markers expression and poor clinical outcomes in CRC patients. Taken together, these findings demonstrate that the molecular mechanisms of ANGPTL1 in colorectal cancer stem cell progression may provide a novel therapeutic strategy for CRC.

MiR-224 promotes lymphatic metastasis by targeting ANGPTL1 in non-small-cell lung carcinoma.

BACKGROUND: MicroRNAs can regulate tumor metastasis either as oncomiRs or suppressor miRNAs. Here, we investigated the role of microRNA 224 (miR-224) in lymphatic metastasis of non-small-cell lung cancer (NSCLC). METHODS: The expression of miR-224 was demonstrated by a validation cohort of 156 lung cancer patients (77 cases with lymphatic metastasis) by quantitative polymerase chain reaction (qPCR). In vitro and in vivo experiments were performed to study the malignant phenotype after upregulation and inhibition of miR-224 expression. Furthermore, the direct target genes of miR-224 were determined by a luciferase reporter assay. RESULTS: First, miR-224 was identified as a highly expressed miRNA in tumor tissues with lymphatic metastasis, with an area under the curve (AUC) of 0.57 as determined by qPCR analysis of a validation cohort of 156 lung cancer patients. Then, in vitro and in vivo experiments indicated that forced expression of miR-224 in H1299 cells promoted not only cell viability, plate colony formation, migration and invasion in vitro but also tumor growth and lung metastasis in vivo. Consistently, inhibition of miR-224 suppressed malignant characteristics both in vitro and in vivo. Moreover, molecular mechanistic research suggested that miR-224 enhanced NSCLC by directly targeting the tumor suppressor angiopoietin-like protein (ANGPTL). CONCLUSIONS: Overall, the collective findings demonstrate that miR-224 is a potential biomarker for the prediction of lymphatic metastasis of NSCLC.

G protein-coupled estrogen receptor stimulates human trophoblast cell invasion via YAP-mediated ANGPTL4 expression.

Insufficient invasion of trophoblast cells into the uterine decidua is associated with preeclampsia (PE). G protein-coupled estrogen receptor (GPER) is a membrane estrogen receptor involved in non-genomic estrogen signaling. GPER is expressed in human trophoblast cells and downregulated GPER levels are noted in PE. However, to date, the role of GPER in trophoblast cells remains largely unknown. Here, we applied RNA sequencing (RNA-seq) to HTR-8/SVneo human trophoblast cells in response to G1, an agonist of GPER, and identified angiopoietin-like 4 (ANGPTL4) as a target gene of GPER. Treatment of trophoblast cells with G1 or 17ß-estradiol (E2) activated Yes-associated protein (YAP), the major downstream effector of the Hippo pathway, via GPER but in a mammalian STE20-like protein kinase 1 (MST1)-independent manner. Using pharmacological inhibitors as well as loss- and gain-of-function approaches, our results revealed that YAP activation was required for GPER-stimulated ANGPTL4 expression. Transwell invasion assays demonstrated that activation of GPER-induced ANGPTL4 promoted cell invasion. In addition, the expression levels of GPER, YAP, and ANGPTL4 were downregulated in the placenta of patients with PE. Our findings reveal a mechanism by which GPER exerts its stimulatory effect on human trophoblast cell invasion by upregulating YAP-mediated ANGPTL4 expression.

Influence of Angptl1 on osteoclast formation and osteoblastic phenotype in mouse cells.

BACKGROUND: Osteoblasts and osteoclasts play important roles during the bone remodeling in the physiological and pathophysiological states. Although angiopoietin family Angiopoietin like proteins (Angptls), including Angptl1, have been reported to be involved in inflammation, lipid metabolism and angiogenesis, the roles of Angptl1 in bone have not been reported so far. METHODS: We examined the effects of Angptl1 on the osteoblast and osteoclast phenotypes using mouse cells. RESULTS: Angptl1 significantly inhibited the osteoclast formation and mRNA levels of tartrate-resistant acid phosphatase and cathepsin K enhanced by receptor activator of nuclear factor κB ligand in RAW 264.7 and mouse bone marrow cells. Moreover, Angptl1 overexpression significantly enhanced Osterix mRNA levels, alkaline phosphatase activity and mineralization induced by bone morphogenetic protein-2 in ST2 cells, although it did not affect the expression of osteogenic genes in MC3T3-E1 and mouse osteoblasts. On the other hand, Angptl1 overexpression significantly reduced the mRNA levels of peroxisome proliferator-activated receptor γ and adipocyte protein-2 as well as the lipid droplet formation induced by adipogenic medium in 3T3-L1 cells. CONCLUSIONS: The present study first indicated that Angptl1 suppresses and enhances osteoclast formation and osteoblastic differentiation in mouse cells, respectively, although it inhibits adipogenic differentiation of 3T3-L1 cells. These data suggest the possibility that Angptl1 might be physiologically related to bone remodeling.

Pericyte-like cells undergo transcriptional reprogramming and distinct functional adaptations in acute lung injury.

We previously reported on the role of pericyte-like cells as functional sentinel immune cells in lung injury. However, much about the biological role of pericytes in lung injury remains unknown. Lung pericyte-like cells are well-positioned to sense disruption to the epithelial barrier and coordinate local inflammatory responses due to their anatomic niche within the alveoli. In this report, we characterized transcriptional responses and functional changes in pericyte-like cells following activation by alveolar components from injured and uninjured lungs in a mouse model of acute lung injury (ALI). Purified pericyte-like cells from lung digests using PDGFRß as a selection marker were expanded in culture as previously described (1). We induced sterile acute lung injury in mice with recombinant human Fas ligand (rhFasL) instillation followed by mechanical ventilation (1). We then collected bronchoalveolar lavage fluid (BALF) from injured and uninjured mice. Purified pericyte-like cells in culture were exposed to growth media only (control), BALF from uninjured mice, and BALF from injured mice for 6 and 24 hours. RNA collected from these treatment conditions were processed for RNAseq. Targets of interest identified by pathway analysis were validated using in vitro and in vivo assays. We observed robust global transcriptional changes in pericyte-like cells following treatment with uninjured and injured BALF at 6 hours, but this response persisted for 24 hours only after exposure to injured BALF. Functional enrichment analysis of pericytes treated with injured BALF revealed the activation of pro-inflammatory, cell migration, and angiogenesis-related pathways, whereas processes associated with tissue development and cell differentiation were down-regulated. We validated select upregulated targets in the inflammatory, angiogenic, and cell migratory pathways using functional biological assays in vitro and in vivo. We conclude that lung pericyte-like cells are highly responsive to alveolar compartment content from both uninjured and injured lungs, but injured BALF elicits a more sustained response. The inflammatory, angiogenic, and migratory changes exhibited by activated pericyte-like cells underscore the phenotypic plasticity of these specialized stromal cells in the setting of acute lung injury.

Effectiveness and Safety of Extracorporeal Shockwave Myocardial Revascularization in Patients With Refractory Angina Pectoris and Heart Failure.

Extracorporeal shockwave myocardial revascularization (ESMR) is a therapy for refractory angina pectoris. Our aim was to assess the efficacy and safety of ESMR in the management of patients with stable coronary artery disease (CAD) and heart failure as well as its effects on inflammation and angiogenesis. In this single-arm prospective trial, we included 48 patients with CAD, myocardial ischemia assessed by radionuclide imaging, echocardiographic evidence of left ventricular systolic dysfunction and without revascularization options. Changes in angina grading score, myocardial perfusion, left ventricular ejection fraction, and six-minute walk test after ESMR therapy were used for efficacy assessment. Changes of inflammation and angiogenesis biomarkers were also evaluated. ESMR therapy was performed using a commercially available cardiac shockwave generator system (Cardiospec; Medispec). After 9 weeks of ESMR therapy, a significant improvement was found regarding the initial angina class, severity of ischemia, left ventricular ejection fraction, and six-minute walk test in most patients. No deleterious side effects after treatment were detected. Regarding biomarkers, endothelial progenitor cells and angiopoietin-3 were significantly increased whereas IL-18 and TGF-ß were significantly decreased after ESMR in the total group. Notably, VEGF, IL-1ß, and lipoxin A4 levels were significantly increased only in patients with myocardial ischemia improvement. In conclusion, ESMR therapy is safe and effective in most but not all patients with CAD and heart failure. ESMR is associated with increased markers of angiogenesis and decreased markers of inflammation. Myocardial ischemia improvement after ESMR is associated with increased markers of angiogenesis and pro-resolving mediators.

Exosomal ANGPTL1 attenuates colorectal cancer liver metastasis by regulating Kupffer cell secretion pattern and impeding MMP9 induced vascular leakiness.

BACKGROUND: Angiopoietin-like protein 1 (ANGPTL1) has been proved to suppress tumor metastasis in several cancers. However, its extracellular effects on the pre-metastatic niches (PMNs) are still unclear. ANGPTL1 has been identified in exosomes, while its function remains unknown. This study was designed to explore the role of exosomal ANGPTL1 on liver metastasis in colorectal cancer (CRC). METHODS: Exosomes were isolated by ultracentrifugation. The ANGPTL1 level was detected in exosomes derived from human CRC tissues. The effects of exosomal ANGPTL1 on CRC liver metastasis were explored by the intrasplenic injection mouse model. The liver PMN was examined by vascular permeability assays. Exosomal ANGPTL1 localization was validated by exosome labeling. The regulatory mechanisms of exosomal ANGPTL1 on Kupffer cells were determined by RNA sequencing. qRT-PCR, Western Blot, and ELISA analysis were conducted to examine gene expressions at mRNA and protein levels. RESULTS: ANGPTL1 protein level was significantly downregulated in the exosomes derived from CRC tumors compared with paired normal tissues. Besides, exosomal ANGPTL1 attenuated liver metastasis and impeded vascular leakiness in the liver PMN. Moreover, exosomal ANGPTL1 was mainly taken up by KCs and regulated the KCs secretion pattern, enormously decreasing the MMP9 expression, which finally prevented the liver vascular leakiness. In mechanism, exosomal ANGPTL1 downregulated MMP9 level in KCs by inhibiting the JAK2-STAT3 signaling pathway. CONCLUSIONS: Taken together, exosomal ANGPTL1 attenuated CRC liver metastasis and impeded vascular leakiness in the liver PMN by reprogramming the Kupffer cell and decreasing the MMP9 expression. This study suggests a suppression role of exosomal ANGPTL1 on CRC liver metastasis and expands the approach of ANGPTL1 functioning.

Respiratory traits and coal workers' pneumoconiosis: Mendelian randomisation and association analysis.

OBJECTIVES: Susceptibility loci of idiopathic pulmonary fibrosis and chronic obstructive pulmonary disease were also significantly associated with the predisposition of coal worker's pneumoconiosis (CWP) in recent studies. However, only a few genes and loci were targeted in previous studies. METHODS: To systematically evaluate the genetic associations between CWP and other respiratory traits, we reviewed the reported genome-wide association study loci of five respiratory traits and then conducted a Mendelian randomisation study and a two-stage genetic association study. RESULTS: Interestingly, we found that for each SD unit, higher lung function was associated with a 66% lower risk of CWP (OR=0.34, 95% CI: 0.15 to 0.77, p=0.010) using conventional Mendelian randomisation analysis (inverse variance weighted method). Moreover, we found susceptibility loci of interstitial lung disease (rs2609255, OR=1.29, p=1.61×10-4) and lung function (rs4651005, OR=1.39, p=1.62×10-3; rs985256, OR=0.73, p=8.24×10-4 and rs6539952, OR=1.28, p=4.32×10-4) were also significantly associated with the risk of CWP. Functional annotation showed these variants were significantly associated with the expression of FAM13A (rs2609255, p=7.4 ×10-4), ANGPTL1 (rs4651005, p=5.4 ×10-7), SPATS2L (rs985256, p=1.1 ×10-5) and RP11-463O9.9 (rs6539952, p=7.1 ×10-6) in normal lung tissues, which were related to autophagy pathway simultaneously according to enrichment analysis. CONCLUSIONS: These results provided a deeper understanding of the genetic predisposition basis of CWP.

Mining the role of angiopoietin-like protein family in gastric cancer and seeking potential therapeutic targets by integrative bioinformatics analysis.

BACKGROUND: The indistinctive effects of antiangiogenesis agents in gastric cancer (GC) can be attributed to multifaceted gene dysregulation associated with angiogenesis. Angiopoietin-like (ANGPTL) proteins are secreted proteins regulating angiogenesis. They are also involved in inflammation and metabolism. Emerging evidences have revealed their various roles in carcinogenesis and metastasis development. However, the mRNA expression profiles, prognostic values, and biological functions of ANGPTL proteins in GC are still elucidated. METHODS: We compared the transcriptional expression levels of ANGPTL proteins between GC and normal gastric tissues using ONCOMINE and TCGA-STAD. The prognostic values were evaluated by LinkedOmics and Kaplan-Meier Plotter, while the association of expression levels with clinicopathological features was generated through cBioPortal. We conducted the functional enrichment analysis with Metascape. RESULTS: The expression of ANGPTL1/3/6 was lower in GC tissues than in normal gastric tissues. High expression of ANGPTL1/2/4 was correlated with short overall survival and post-progression survival in GC patients. Upregulated ANGPTL1/2 was correlated with higher histological grade, non-intestinal Lauren classification, and advanced T stage, while ANGPTL4 exhibited high expression in early T stage, M1 stage, and non-intestinal Lauren classification. CONCLUSIONS: Integrative bioinformatics analysis suggests that ANGPTL1/2/4 may be potential therapeutic targets in GC patients. Among them, ANGPTL2 acts as a GC promoter, while ANGPTL1/4's role in GC is still uncertain.

A 21­gene Support Vector Machine classifier and a 10­gene risk score system constructed for patients with gastric cancer.

Gastric cancer (GC) ranks fifth in terms of incidence and third in terms of tumor mortality worldwide. The present study was designed to construct a Support Vector Machine (SVM) classifier and risk score system for GC. The GSE62254 (training set) and GSE26253 (validation set 2) datasets were downloaded from the Gene Expression Omnibus database. Furthermore, the gene expression profile of GC (validation set 1) was obtained from The Cancer Genome Atlas database. Differentially expressed genes (DEGs) between recurrent and non­recurrent samples were determined using the limma package. The feature genes were selected using the Caret package, and an SVM classifier was built using the e1071 package. Using the penalized package, the optimal predictive genes for constructing a risk score system were screened. Finally, stratification analysis of clinical factors and pathway enrichment analysis were performed using Gene Set Enrichment Analysis. A total of 239 DEGs were identified in GSE62254, among which 114 DEGs were significantly associated with both recurrence­free survival and overall survival. Subsequently, 21 feature genes were screened from the 114 DEGs, and an SVM classifier was built. A risk score system for survival prediction was constructed, following the selection of 10 optimal genes, including A­kinase anchoring protein 12, angiopoietin­like protein 1, cysteine­rich sequence 1, myeloid/lymphoid or mixed­lineage leukemia, translocated to chromosome 11, neuron navigator 3, neurobeachin, nephroblastoma overexpressed, pleiotrophin, tumor suppressor candidate 3 and zinc finger and SCAN domain containing 18. The stratification analysis revealed that pathological stage was an independent prognostic clinical factor in the high­risk group. Additionally, eight significant pathways were associated with the 10­gene signature. The SVM classifier and risk score system may be applied for classifying and predicting the prognosis of patients with GC, respectively.

Long non-coding RNA ANGPTL1-3 promotes multiple myeloma bortezomib resistance by sponging miR-30a-3p to activate c-Maf expression.

Multiple Myeloma (MM) is a malignant hematological disease characterized by monoclonal proliferation of plasma cells in the bone marrow. In recent years, the widespread use of new drugs based on bortezomib (Btz) has significantly improved the remission rate of MM patients. However, drug resistance and disease relapse occur within a few years and MM is still considered to be an incurable disease. The amplification of the long arm of chromosome 1 is one of the most common genetic abnormalities in MM patients. Here, we found that long non-coding RNA ANGPTL1-3 which located in 1q region was overexpressed in MM. Lnc-ANGPTL1-3 expression was correlated with MM International Staging System (ISS) and overall survival. Notably, knockdown of lnc-ANGPTL1-3 increased Btz sensitivity of MM cells. Following exploration revealed that lnc-ANGPTL1-3 competitively interacted with miR-30a-3p to c-Maf, a transcription factor which was reported to be associated with Btz resistance. Taken together, our findings demonstrate that lnc-ANGPTL1-3/miR-30a-3p/c-Maf axis plays a critical role in MM Btz resistance.

Using human sequencing to guide craniofacial research.

A recent convergence of technological innovations has re-energized the ability to apply genetics to research in human craniofacial development. Next-generation exome and whole genome sequencing have significantly dropped in price, making it relatively trivial to sequence and analyze patients and families with congenital craniofacial anomalies. A concurrent revolution in genome editing with the use of the CRISPR-Cas9 system enables the rapid generation of animal models, including mouse, which can precisely recapitulate human variants. Here, we summarize the choices currently available to the research community. We illustrate this approach with the study of a family with a novel craniofacial syndrome with dominant inheritance pattern. The genomic analysis suggested a causal variant in AMOTL1 which we modeled in mice. We also made a novel deletion allele of Amotl1. Our results indicate that Amotl1 is not required in the mouse for survival to weaning. Mice carrying the variant identified in the human sequencing studies, however, do not survive to weaning in normal ratios. The cause of death is not understood for these mice complicating our conclusions about the pathogenicity in the index patient. Thus, we highlight some of the powerful opportunities and confounding factors confronting current craniofacial genetic research.

ANGPTL1 Interacts with Integrin α1ß1 to Suppress HCC Angiogenesis and Metastasis by Inhibiting JAK2/STAT3 Signaling.

Downregulation of tumor suppressor signaling plays an important role in the pathogenesis of hepatocellular carcinoma (HCC). Here, we report that downregulation of the angiopoietin-like protein ANGPTL1 is associated with vascular invasion, tumor thrombus, metastasis, and poor prognosis in HCC. Ectopic expression of ANGPTL1 in HCC cells effectively decreased their in vitro and in vivo tumorigenicity, cell motility, and angiogenesis. shRNA-mediated depletion of ANGPTL1 exerted opposing effects. ANGPTL1 promoted apoptosis via inhibition of the STAT3/Bcl-2-mediated antiapoptotic pathway and decreased cell migration and invasion via downregulation of transcription factors SNAIL and SLUG. Furthermore, ANGPTL1 inhibited angiogenesis by attenuating ERK and AKT signaling and interacted with integrin α1ß1 receptor to suppress the downstream FAK/Src-JAK-STAT3 signaling pathway. Taken together, these results suggest ANGPTL1 as a prognostic biomarker and novel therapeutic agent in HCC. Cancer Res; 77(21); 5831-45. ©2017 AACR.

The Circular RNA Interacts with STAT3, Increasing Its Nuclear Translocation and Wound Repair by Modulating Dnmt3a and miR-17 Function.

Delayed or impaired wound healing is a major health issue worldwide, especially in patients with diabetes and atherosclerosis. Here we show that expression of the circular RNA circ-Amotl1 accelerated healing process in a mouse excisional wound model. Further studies showed that ectopic circ-Amotl1 increased protein levels of Stat3 and Dnmt3a. The increased Dnmt3a then methylated the promoter of microRNA miR-17, decreasing miR-17-5p levels but increasing fibronectin expression. We found that Stat3, similar to Dnmt3a and fibronectin, was a target of miR-17-5p. Decreased miR-17-5p levels would increase expression of fibronectin, Dnmt3a, and Stat3. All of these led to increased cell adhesion, migration, proliferation, survival, and wound repair. Furthermore, we found that circ-Amotl1 not only increased Stat3 expression but also facilitated Stat3 nuclear translocation. Thus, the ectopic expressed circ-Amotl1 and Stat3 were mainly translocated to nucleus. In the presence of circ-Amotl1, Stat3 interacted with Dnmt3a promoter with increased affinity, facilitating Dnmt3a transcription. Ectopic application of circ-Amotl1 accelerating wound repair may shed light on skin wound healing clinically.

ANGPTL1 attenuates colorectal cancer metastasis by up-regulating microRNA-138.

BACKGROUND: Angiopoietin-like protein 1 (ANGPTL1) has been reported to suppress migration and invasion in lung and breast cancer, acting as a novel tumor suppressor candidate. Nevertheless, its effects on colorectal cancer (CRC) remain poorly defined. In this study, we aim to demonstrate the biological function of ANGPTL1 in CRC cells. METHODS: We explored ANGPTL1 mRNA expression in human CRC tissues and its association with prognosis. CRC cell lines overexpressing ANGPTL1 or with ANGPTL1 knocked down were constructed and analyzed for changes in proliferation, colony formation, migration and invasion. ANGPTL1-regulated microRNAs were analyzed, and microRNA inhibitor and mimics were used to explore the role of microRNA in ANGPTL1-associated biological function. RESULTS: ANGPTL1 mRNA expression was down-regulated in CRC tissues, and high ANGPTL1 expression predicted better survival in CRC patients. ANGPTL1 overexpression resulted in suppressed migration and invasion in vitro, and it prolonged overall survival in mouse models. By contrast, its down-regulation enhanced migration and invasion of CRC cells. MicroRNA-138 expression was positively correlated with ANGPTL1 mRNA level in CRC tissues and up-regulated by ANGPTL1 in CRC cells. In addition, the microRNA-138 inhibitor or mimics could reverse or promote the ANGPTL1-mediated inhibition of the migratory capacity of CRC cells, respectively. CONCLUSIONS: This study is the first to demonstrate the biological function of ANGPTL1 in CRC cells. ANGPTL1 expression was down-regulated in CRC tissues and inversely correlated with poor survival. ANGPTL1 repressed migration and invasion of CRC cells, and microRNA-138 was involved in this process.

A new angiogenesis prognostic index with VEGFA, PlGF, and angiopoietin1 predicts survival in patients with advanced gastric cancer.

BACKGROUND/AIM: The role of angiogenic factors in gastric cancer is not clear. We aimed to assess the role of vascular endothelial growth factor A (VEGFA), angiopoietin 1 (Ang-1), and placental growth factor (PlGF) in the prognosis of patients with advanced gastric cancer. MATERIALS AND METHODS: Thirty consecutive patients treated with a modified DCF (docetaxel, cisplatin, and fluorouracil) regimen were included in the study. The plasma VEGFA, Ang-1, and PlGF levels of the patients before treatment and following two cycles of chemotherapy were measured and evaluated as prognostic factors. RESULTS: Poor performance status and lower Ang-1 levels were correlated with poor overall survival (OS). No significant correlation between VEGFA or PlGF and OS was found. An angiogenesis prognostic index (API) based on the levels of VEGFA, Ang-1, and PlGF was found to be highly correlated with OS. Performance status and API were found as independent prognostic factors for OS. Furthermore, a decrease in VEGFA by 25% from the pretreatment level was also found as a prognostic factor for OS independent of response to DCF regimen. CONCLUSION: Our results support the use of the new API including VEGFA, Ang-1, and PlGF levels in patients with advanced gastric cancer as a predictor of survival.

Amotl1 mediates sequestration of the Hippo effector Yap1 downstream of Fat4 to restrict heart growth.

Although in flies the atypical cadherin Fat is an upstream regulator of Hippo signalling, the closest mammalian homologue, Fat4, has been shown to regulate tissue polarity rather than growth. Here we show in the mouse heart that Fat4 modulates Hippo signalling to restrict growth. Fat4 mutant myocardium is thicker, with increased cardiomyocyte size and proliferation, and this is mediated by an upregulation of the transcriptional activity of Yap1, an effector of the Hippo pathway. Fat4 is not required for the canonical activation of Hippo kinases but it sequesters a partner of Yap1, Amotl1, out of the nucleus. The nuclear translocation of Amotl1 is accompanied by Yap1 to promote cardiomyocyte proliferation. We, therefore, identify Amotl1, which is not present in flies, as a mammalian intermediate for non-canonical Hippo signalling, downstream of Fat4. This work uncovers a mechanism for the restriction of heart growth at birth, a process which impedes the regenerative potential of the mammalian heart.