ANGPTL1 is a potential biomarker for differentiated thyroid cancer diagnosis and recurrence

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.

Angiopoietin-Like Proteins: Cardiovascular Biology and Therapeutic Targeting for the Prevention of Cardiovascular Diseases

Despite the best pharmacologic tools available, cardiovascular diseases (CVDs) remain a major cause of morbidity and mortality in developed countries. After 2 decades of research, new therapeutic targets, such as angiopoietin-like proteins (ANGPTLs), are emerging. ANGPTLs belong to a family of 8 members, from ANGPTL1 to ANGPTL8; they have structural homology with angiopoietins and are secreted in the circulation. ANGPTLs display a multitude of physiological and pathologic functions; they contribute to inflammation, angiogenesis, cell death, senescence, hematopoiesis, and play a role in repair, maintenance, and tissue homeostasis. ANGPTLs-particularly the triad ANGPTL3, 4, and 8-have an established role in lipid metabolism through the regulation of triacylglycerol trafficking according to the nutritional status. Some ANGPTLs also contribute to glucose metabolism. Therefore, dysregulation in ANGPTL expression associated with abnormal circulating levels are linked to a plethora of CVD and metabolic disorders including atherosclerosis, heart diseases, diabetes, but also obesity and cancers. Because ANGPTLs bind to different receptors according to the cell type, antagonists are therapeutically inadequate. Recently, direct inhibitors of ANGPTLs, mainly ANGPTL3, have been developed, and specific monoclonal antibodies and antisense oligonucleotides are currently being tested in clinical trials. The aim of the current review is to provide an up-to-date preclinical and clinical overview on the function of the 8 members of the ANGPTL family in the cardiovascular system, their contribution to CVD, and the therapeutic potential of manipulating some of them.

Case Report: A papillary thyroid microcarcinoma patient with skip lymph node metastasis and multiple distant metastasis

Papillary thyroid carcinoma (PTC) is the most common type of thyroid cancer. Papillary thyroid microcarcinoma (PTMC) is defined as PTC with a diameter less than 1 centimeter. Most lymph nodes of PTC patients have metastasized to the central neck, and a few lymph nodes have metastasized to the lateral neck. Skip lymph node metastasis, that is, lateral cervical lymph node metastasis without central lymph node metastasis, is even less common. Additionally, distant metastasis of PTMC is also rare, mainly occurring in the lung and bone. Here, we reported a case of PTMC patient with skip lymph node metastasis and multiple distant metastasis. The patient presented with a huge shoulder mass and the primary tumor was found to originate from the thyroid. However, the patient only suffered with PTMC via postoperative pathological results, and interestingly, the patient only had skip lymph node metastasis. Thus, we should focus on PTMC patients with lateral cervical lymph nodes metastasis, especially those with skip metastasis. In addition, this case provides a new perspective for us to understand of skip lymph metastasis and distant metastasis of PTMC.

Identification of Colon Cancer-Related RNAs Based on Heterogeneous Networks and Random Walk

Colon cancer is considered as a complex disease that consists of metastatic seeding in early stages. Such disease is not simply caused by the action of a single RNA, but is associated with disorders of many kinds of RNAs and their regulation relationships. Hence, it is of great significance to study the complex regulatory roles among mRNAs, miRNAs and lncRNAs for further understanding the pathogenic mechanism of colon cancer. In this study, we constructed a heterogeneous network consisting of differentially expressed mRNAs, miRNAs and lncRNAs. This contains three kinds of vertices and six types of edges. All RNAs were re-divided into three categories, which were “related”, “irrelevant” and “unlabeled”. They were processed by dynamic excitation restart random walk (RW-DIR) for identifying colon cancer-related RNAs. Ten RNAs were finally obtained related to colon cancer, which were hsa-miR-2682-5p, hsa-miR-1277-3p, ANGPTL1, SLC22A18AS, FENDRR, PHLPP2, hsa-miR-302a-5p, APCDD1, MEX3A and hsa-miR-509-3-5p. Numerical experiments have indicated that the proposed network construction framework and the following RW-DIR algorithm are effective for identifying colon cancer-related RNAs, and this kind of analysis framework can also be easily extended to other diseases, effectively narrowing the scope of biological experimental research.

The Role of ANGPTL Gene Family Members in Hepatocellular Carcinoma

Background

Hepatocellular carcinoma (HCC) is highly aggressive with a poor prognosis and survival rate. Certain ANGPTL members have been implicated in tumor progression. However, the relevance of the ANGPTL gene family to HCC remains poorly understood. In this study, we explored the role of ANGPTLs in the prognosis of HCC.

Methods

From the CCLE database, we studied the expression of ANGPTLs in a range of cancer cell lines. The UCSC, HCCDB, and Human Protein Atlas databases were used to analyze the differences in mRNA and protein expression of ANGPTLs in HCC tissues. Additionally, the correlation between ANGPTL mRNA and methylation levels and clinicopathological features were assessed in the TCGA database. The correlation between ANGPTL mRNA and overall survival was determined by the Kaplan-Meier plotter. cBioPortal database was used to analyze ANGPTL genomic alterations. Genes associated with ANGPTLs were determined by enrichment with KEGG. Moreover, the differentially expressed genes of ANGPTLs were analyzed by the LinkedOmics database, and the KEGG pathway and miRNA targets of ANGPTLs were also enriched.

Results

There was a significant correlation between the ANGPTL members (excluding ANGPTL2) and the prognosis of HCC patients according to the Kaplan-Meier plotter analysis (p < 0.05). ANGPTL1 was the gene with the highest mutation frequency. ANGPTLs are involved in certain pathways that may influence the development of HCC.

Conclusion

In summary, the expression of some members of ANGPTLs was significantly correlated with HCC prognosis, suggesting that the ANGPTL gene family members may be promising molecular markers for HCC treatment and prognosis.

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.

Identification of Immune-Related Prognostic Markers in Gastric Cancer

Gastric cancer (GC) is a malignant tumor with a high fatality rate. Poor prognosis is the main cause of death caused by GC. In this study, the gene expression difference between GC and the control group was analyzed. Differentially expressed genes (DEGs) related to immunity were screened for enrichment analysis. The differences in immune cell infiltration and immune function between GC and normal were identified. Cox regression analysis and survival analysis were used to determine the prognostic genes of GC in TCGA and GSE62254. The potential prognostic role of genes was further evaluated by risk score. Difference genes in GC were analyzed in TCGA. Candidate genes in TCGA and GSE62254 are analyzed, and prognostic genes are determined. The potential prognostic role of genes was further evaluated by risk score. The immune-related prognostic markers in GC were determined. FABP4, LBP, LCN1, CMA1, INHBA, ANGPTL1, ACKR1, GHR, and OGN may be used as markers for monitoring the prognosis of GC in the future.

Distinct Clinical Impact and Biological Function of Angiopoietin and Angiopoietin-like Proteins in Human Breast Cancer

Secreted angiopoietin/angiopoietin-like (ANGPT/ANGPTL) proteins are involved in many biological processes. However, the role of these proteins in human breast cancers (BCs) remains largely unclear. Here, we conducted integrated omics analyses to evaluate the clinical impact of ANGPT/ANGPTL proteins and to elucidate their biological functions. In BCs, we identified rare mutations in ANGPT/ANGPTL genes, frequent gains of ANGPT1, ANGPT4, and ANGPTL1, and frequent losses of ANGPT2, ANGPTL5, and ANGPTL7, but observed that ANGPTL1, 2, and 4 were robustly downregulated in multiple datasets. The expression levels of ANGPTL1, 5, and 8 were positively correlated with overall survival (OS), while the expression levels of ANGPTL4 were negatively correlated with OS. Additionally, the expression levels of ANGPTL1 and 7 were positively correlated with distant metastasis-free survival (DMFS), while the expression levels of ANGPT2 and ANGPTL4 were negatively correlated with DMFS. The prognostic impacts of ANGPT/ANGPTL genes depended on the molecular subtypes and on clinical factors. We discovered that various ANGPT/ANGPTL genes were co-expressed with various genes involved in different pathways. Finally, with the exception of ANGPTL3, the remaining genes showed significant correlations with cancer-associated fibroblasts, endothelial cells, and microenvironment score, whereas only ANGPTL6 was significantly correlated with immune score. Our findings provide strong evidence for the distinct clinical impact and biological function of ANGPT/ANGPTL proteins, but the question of whether some of them could be potential therapeutic targets still needs further investigation in BCs.