Angioarrestin mRNA expression in early-stage lung cancers

The JAK/STAT signaling pathway: from bench to clinic

The Janus kinase/signal transducer and activator of transcription (JAK/STAT) signaling pathway was discovered more than a quarter-century ago. As a fulcrum of many vital cellular processes, the JAK/STAT pathway constitutes a rapid membrane-to-nucleus signaling module and induces the expression of various critical mediators of cancer and inflammation. Growing evidence suggests that dysregulation of the JAK/STAT pathway is associated with various cancers and autoimmune diseases. In this review, we discuss the current knowledge about the composition, activation, and regulation of the JAK/STAT pathway. Moreover, we highlight the role of the JAK/STAT pathway and its inhibitors in various diseases.

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

Differentiated thyroid cancer (DTC) is a common type of cancer among women with an increasing worldwide incidence rate. However, there are no specific and sensitive molecular biomarkers for DTC diagnosis or prognosis. Angiopoietin-like protein 1 (ANGPTL1) may be a novel tumor suppressor in lung, breast, colorectal and hepatocellular carcinoma. However, little is known about the influence of ANGPTL1 on the malignant properties of thyroid cancer cells or DTC recurrence in patients. Thus, the present study aimed to investigate the effects of ANGPTL1 on thyroid cancer malignancy or recurrence. The present study examined the mRNA levels of ANGPTL1 in thyroid cancer and paracancerous tissues using RNA sequencing data from The Cancer Genome Atlas. The present study also determined the effects of ANGPTL1 on thyroid cancer cell proliferation using the Cell Counting Kit-8 assay. Associations were identified among ANGPTL1 expression levels and thyroid cancer proliferation, migration and metastasis using The Cancer Genome Atlas data set and by Gene Set Enrichment Analysis. The expression of ANGPTL1 in patients with DTC and without recurrence was compared in order to assess its potential as a prognostic biomarker for DTC. In addition, ANGPTL1 concentrations in the serum of patients with DTC and individuals with benign thyroid nodules were compared to evaluate the sensitivity and specificity of ANGPTL1 as a predictive biomarker for DTC. The results of the present study demonstrated that ANGPTL1 expression levels were lower in thyroid cancer compared with those in adjacent normal thyroid tissues. ANGPTL1 expression was observed to decrease with thyroid cancer progression. In addition, ANGPTL1 was demonstrated to inhibit thyroid cancer cell proliferation, migration and invasion and ANGPTL1 expression levels were reduced in patients with DTC with recurrence compared with those in patients with non-recurrent DTC. Additionally, serum concentrations of ANGPTL1 in patients with DTC were decreased compared with those in individuals with benign thyroid nodules. In conclusion, ANGPTL1 may be a novel predictive biomarker for DTC diagnosis and recurrence in patients with DTC.

The Roles of ANGPTL Families in Cancer Progression

Angiopoietins play important roles in angiogenesis and the maintenance of hematopoietic stem cells. Angiopoietin-like proteins (ANGPTLs) are identified as proteins structurally similar to angiopoietins, and the ANGPTL family now consists of eight members. ANGPTLs are secretary proteins, and some ANGPTLs are not only angiogenic factors but also proteins with multiple functions such as glucose metabolism, lipid metabolism, redox regulation and chronic inflammation. Chronic inflammation is one of the key factors in carcinogenesis and cancer growth, proliferation, invasion and metastasis. ANGPTL 2, 3, 4, 6 and 7 are pro-inflammatory factors and regulate cancer progression, while ANGPTL1 inhibits tumor angiogenesis and metastasis. In this review, we describe the roles of ANGPTLs in cancer progression and discuss the possibility of disturbing the progression of cancer by regulating ANGPTLs expression.

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.

Electronic supplementary material

The online version of this article (doi:10.1186/s13046-017-0548-7) contains supplementary material, which is available to authorized users.

Angiopoietin-like proteins: a comprehensive look

Angiopoietin-like proteins (ANGPTLs) are a family of proteins structurally similar to the angiopoietins. To date, eight ANGPTLs have been discovered, namely ANGPTL1 to ANGPTL8. Emerging evidence implies a key role for ANGPTLs in the regulation of a plethora of physiological and pathophysiological processes. Most of the ANGPTLs exhibit multibiological properties, including established functional roles in lipid and glucose metabolism, inflammation, hematopoiesis, and cancer. This report represents a systematic and updated appraisal of this class of proteins, focusing on the main features of each ANGPTL.

Angiopoietin-like protein 1 expression is related to intermuscular connective tissue and cartilage development

Angptl1, a member of the angiopoietin-related protein family, is known to regulate angiogenesis, but little is known of its potential role in other processes. To identify the expression pattern and possible role of angptl1 during embryogenesis, we used gene targeting to generate angptl1-deficient, nLacZ knockin mice. Staining for beta-galactosidase from embryonic day 9.5 to 6 months of age revealed that angptl1 was initially expressed in the paraxial mesoderm. Expression then shifted to intermuscular connective tissue (fascial plane), joint capsules, and perichondrium (laryngo-trachea, ribs, and long bones), but not the muscles. The vasculature, central and peripheral nervous systems, digestive, respiratory, and other major organ systems did not show any angptl1 expression. This expression pattern suggests that angptl1 is related to development of the connective tissue and cartilage. Lack of phenotype in mutant mice may be due to a functional redundancy from other related factors.

Angiopoietin-related/angiopoietin-like proteins regulate angiogenesis

A general understanding of the molecular mechanisms underlying angiogenesis is emerging from the analysis of targeted mutations in vasculature-related genes. These analyses reveal that angiopoietin signaling through the TIE2 receptor is involved in regulating angiogenesis. Recently, we and several other groups have independently identified several molecules containing a coiled-coil domain and a fibrinogen-like domain, both of which are structurally conserved in angiopoietins. Because these molecules do not bind to the angiopoietin-specific receptor,TIE2, they have been named angiopoietin-related proteins (ARPs) or angiopoietin-like proteins (Angptls). ARPs/Angptls, which are all currently orphan ligands, also have potent activity for regulating angiogenesis as proangiogenic or antiangiogenic factors, suggesting that their receptors may be expressed on endothelial cells. In addition, ARPs/Angptls show pleiotropic effects not only on vascular cells but also on cells of other lineages, such as skin and chondrocyte cells. More recent studies have proposed that ARPs/Angptls are involved in various pathologies, such as tumor angiogenesis and metabolic diseases. To summarize the current findings relating to these proteins, we focus in this review on the functions of ARPs/Angptls as new angiogenic modulating factors in the vascular system and discuss the pleiotropic functions of ARPs/Angptls in nonvascular cell lineages.