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.

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.

Long noncoding RNA GAS5 inhibits metastasis by targeting miR-182/ANGPTL1 in hepatocellular carcinoma

Intrahepatic and extrahepatic metastases are responsible for the majority of hepatocellular carcinoma (HCC)-related mortalities. Long noncoding RNAs (lncRNAs) exert important functions in modulating various tumor behaviors. However, the functions and mechanisms of lncRNAs in HCC metastasis remain largely unknown. In this study, downregulation of lncRNA growth arrest-specific 5 (GAS5) was observed in HCC tissues and cells, and predicted poor prognosis of patients with HCC. Through performing gain- and loss-of-function experiments, we found that GAS5 could obviously inhibit migration and invasion of HCC cells in vitro, and suppress tumor metastasis in vivo. Mechanistically, GAS5 functioned as a tumor suppressor in HCC metastasis through directly interacting with miR-182 and abrogating its oncogenic function in this setting. Moreover, GAS5 acted as a competing endogenous RNA (ceRNA) for miR-182 to upregulate the expression of anti-metastasis protein ANGPTL1. Finally, we demonstrated that using ultrasound targeted microbubble destruction (UTMD)-mediated GAS5 transfection could significantly decrease migratory and invasive abilities of HCC cells. Collectively, our study first reveals the mechanism of GAS5/miR-182/ANGPTL1 axis in suppressing HCC metastasis, which provides promising new avenues for therapeutic intervention against HCC progression.

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.

Aberrant expression of angiopoietin-like proteins 1 and 2 in cumulus cells is potentially associated with impaired oocyte developmental competence in polycystic ovary syndrome

Polycystic ovary syndrome (PCOS) is a heterogeneous endocrine disorder associated with obesity, insulin resistance, hyperandrogenism, alterations in ovarian angiogenesis and impaired oocyte competence. Emerging evidence demonstrates that angiopoietin-like protein 1 (ANGPTL1) and angiopoietin-like protein 2 (ANGPTL2) have an important influence on angiogenesis, androgen biosynthesis, insulin resistance and adipocytes function. In this study, we set out to determine the potential relationship between ANGPTL1, ANGPTL2 and oocyte competence in PCOS through analyzing the expression levels and dynamic pattern of the two genes in cumulus cells (CCs) during different phases of nuclear maturation of PCOS patients and control groups undergoing controlled ovarian hyperstimulation (COH) for in vitro fertilization and embryo transfer. We found that the relative abundance of ANGPTL1 and ANGPTL2 transcripts in CCs from patients with PCOS showed dynamic changes during oocyte maturation. Specifically, their expressions were increased significantly at the Metaphase II stage. In summary, the present novel evidence indicates that the expression patterns of ANGPTL1 and ANGPTL2 mRNAs are disordered during oocyte maturation in PCOS, which were potentially related to aberrant oocyte quality and developmental potency, at least in part, via pathological angiogenesis and metabolism.