Inhibition of angiopoietin 2 attenuates lumen formation of tumour-associated vessels in vivo

ALS-L1023 from Melissa officinalis Alleviates Liver Fibrosis in a Non-Alcoholic Fatty Liver Disease Model

ALS-L1023 is an ingredient extracted from Melissa officinalis L. (Labiatae; lemon balm), which is known as a natural medicine that suppresses angiogenesis. Herein, we aimed to determine whether ALS-L1023 could alleviate liver fibrosis in the non-alcoholic fatty liver disease (NAFLD) model. C57BL/6 wild-type male mice (age, 6 weeks old) were fed a choline-deficient high-fat diet (CDHFD) for 10 weeks to induce NAFLD. For the next 10 weeks, two groups of mice received the test drug along with CDHFD. Two doses (a low dose, 800 mg/kg/day; and a high dose, 1200 mg/kg/day) of ALS-L1023 were selected and mixed with feed for administration. Obeticholic acid (OCA; 10 mg/kg/day) was used as the positive control. Biochemical analysis revealed that the ALS-L1023 low-dose group had significantly decreased alanine transaminase and aspartate transaminase. The area of fibrosis significantly decreased due to the administration of ALS-L1023, and the anti-fibrotic effect of ALS-L1023 was greater than that of OCA. RNA sequencing revealed that the responder group had lower expression of genes related to the hedgehog-signaling pathway than the non-responder group. ALS-L1023 may exert anti-fibrotic effects in the NAFLD model, suggesting that it may provide potential benefits for the treatment of liver fibrosis.

Therapeutic approach for digestive system cancers and potential implications of exercise under hypoxia condition: what little is known? a narrative review

BACKGROUND

Cancer, like other chronic pathologies, is associated with the presence of hypoxic regions due to the uncontrolled cell growth. Under this pathological hypoxic condition, various molecular signaling pathways are activated to ensure cell survival, such as those that govern angiogenesis, erythropoiesis, among others. These molecular processes are very similar to the physiological response caused by exposure to altitude (natural hypobaric systemic hypoxia), the use of artificial hypoxia devices (systemic normobaric simulated hypoxia) or the delivery of vascular occlusion to the extremities (also called local hypoxia by the blood flow restriction technique). "Tumor hypoxia" has gained further clinical importance due to its crucial role in both tumor progression and resistance to treatment. However, the ability to manipulate this pathway through physical exercise and systemic hypoxia-mediated signaling pathways could offer an important range of therapeutic opportunities that should be further investigated.

METHODS

This review is focused on the potential implications of systemic hypoxia combined with exercise in digestive system neoplasms prognosis. Articles included in the review were retrieved by searching among the three main scientific databases: PubMed, Scopus, and Embase.

FINDINGS

The findings of this review suggest that exercise performed under systemic hypoxic conditions could have a positive impact in prognosis and quality of life of the population with digestive system cancers.

CONCLUSIONS

Further studies are needed to consider this paradigm as a new potential intervention in digestive oncological population.

Antiangiogenic Drugs in NASH: Evidence of a Possible New Therapeutic Approach

Non-alcoholic fatty liver disease is the most common liver disorder worldwide, and its progressive form non-alcoholic steatohepatitis (NASH) is a growing cause of liver cirrhosis and hepatocellular carcinoma (HCC). Lifestyle changes, which are capable of improving the prognosis, are hard to achieve, whereas a pharmacologic therapy able to combine efficacy and safety is still lacking. Looking at the pathophysiology of various liver diseases, such as NASH, fibrosis, cirrhosis, and HCC, the process of angiogenesis is a key mechanism influencing the disease progression. The relationship between the worsening of chronic liver disease and angiogenesis may suggest a possible use of drugs with antiangiogenic activity as a tool to stop or slow the progression of the disorder. In this review, we highlight the available preclinical data supporting a role of known antiangiogenic drugs (e.g., sorafenib), or phytotherapeutic compounds with multiple mechanism of actions, including also antiangiogenic activities (e.g., berberine), in the treatment of NASH.

Integrated data analysis identifies potential inducers and pathways during the endothelial differentiation of bone-marrow stromal cells by DNA methyltransferase inhibitor, 5-aza-2'-deoxycytidine

Bone-Marrow Stromal Cells (BMSCs)-derived vascular endothelial cells (VECs) is regarded as an important therapeutic strategy for spinal cord injury, disc degeneration, cerebral ischemic disease and diabetes. The change in DNA methylation level is essential for stem cell differentiation. However, the DNA methylation related mechanisms underlying the endothelial differentiation of BMSCs are not well understood. In this study, DNA methyltransferase inhibitor, 5-aza-2'-deoxycytidine (5-aza-dC) significantly elevated the endothelial markers expression (CD31/PECAM1, CD105/ENG, eNOS and VE-cadherin), as well as promoted the capacity of angiogenesis on Matrigel. The result of Alexa 488-Ac-LDL uptake assay indicated that the differentiation ratio of BMSCs into VECs was 68.7% in 5-azaz-dC induced differentiation. And then we screened differentiation inducers with altered expression patterns and DNA methylation levels in four important families (VEGF, ANG, FGF and ETS). By integrating these data, five endothelial differentiation inducers (VEGFA, ANGPT2, FGF2, FGF9 and ETS1) which were directly upregulated by 5-aza-dC and five indirect factors (FGF1, FGF3, ETS2, ETV1 and ETV4) were identified. These data suggested that 5-aza-dC is an excellent chemical molecule for BMSCs differentiation into functional VECs and also provided essential clues for DNA methylation related signaling during 5-aza-dC induced endothelial differentiation of BMSCs.

Overexpression of angiopoietin 2 promotes the formation of oral squamous cell carcinoma by increasing epithelial-mesenchymal transition-induced angiogenesis

Oral squamous cell carcinoma (OSCC) is the most common cancer of the head and neck and is associated with a high rate of lymph node metastasis. The initial step in the metastasis and transition of tumors is epithelial-mesenchymal transition (EMT)-induced angiogenesis, which can be mediated by angiopoietin 2 (ANG2), a key regulatory factor in angiogenesis. In the present study, immunohistochemistry and real-time quantitative reverse transcriptase (qRT-PCR) were used to measure the expression of ANG2 in OSCC tissues. Plasmids encoding ANG2 mRNA were used for increased ANG2 expression in the OSCC cell line TCA8113. The short interfering RNA (siRNA)-targeting ANG2 mRNA sequences were used to inhibit ANG2 expression in TCA8113 cells. Subsequently, transwell assays were performed to examine the effects of ANG2 on TCA8113 cell migration and invasion. Furthermore, in vivo assays were performed to assess the effect of ANG2 on tumor growth. Terminal deoxynucleotidyl transferase dUTP nick-end labeling (TUNEL) assays and immunohistochemistry were used to examine cell apoptosis and angiogenesis in tumor tissues, respectively. Finally, western blot analysis was performed to evaluate tumor formation-related proteins in OSCC tissues. We found that protein expression of ANG2 was remarkably upregulated in OSCC tissues. Overexpression of ANG2 increased the migration and invasion of TCA8113 cells by regulating EMT. Further investigations showed that overexpression of ANG2 increased tumor growth in nude mice, and angiogenesis of OSCC tissues increased in the presence of ANG2 overexpression. Overexpression of ANG2 also reduced cell apoptosis in tumor tissue cells. Finally, we found that overexpression of ANG2 resulted in changes in the expression of tumor formation-related proteins including vimentin, E-cadherin, Bim, PUMA, Bcl-2, Bax, Cyclin D1, PCNA and CD31. Our findings show that ANG2 has an important role in the migration and invasion of OSCC. More importantly, further investigations suggested that overexpression of ANG2 might increase OSCC metastasis by promoting angiogenesis in nude mice. This stimulatory effect could be achieved by inducing abnormal EMT and by reducing apoptosis and increasing proliferation of cells.

Suppression of KSHV-induced angiopoietin-2 inhibits angiogenesis, infiltration of inflammatory cells, and tumor growth

Kaposi's sarcoma (KS) is a highly angiogenic and inflammatory neoplasia. The angiogenic and inflammatory cytokine angiopoietin-2 (Ang-2) is strongly expressed in KS due to Kaposi's sarcoma-associated herpesvirus (KSHV) infection. In the present study, we determined how Ang-2 contributes to development of KS by using telomerase-immortalized human umbilical vein endothelial cells (TIVE) as a model, which become malignantly transformed and express increased levels of Ang-2 following KSHV infection. Ang-2 released from TIVE-KSHV cells induces tyrosine phosphorylation of Tie-2 receptor from both human and mouse endothelial cells and promotes angiogenesis in nude mice. Functional inhibition or expressional "knock-down" of Ang-2 in these cells blocks angiogenesis and inhibits tumor growth. Ang-2 suppression also reduces the numbers of infiltrating monocytes/macrophages in tumors. In transwell-based cell migration assays, Ang-2 indeed enhances migration of human monocytes in a dose-dependent manner. These results underscore a pivotal role of KSHV-induced Ang-2 in KS tumor development by promoting both angiogenesis and inflammation. Our data also suggest that selective drug targeting of Ang-2 may be used for treatment of KS.

Heterochromatin Protein 1 Alpha (HP1α: CBX5) is a Key Regulator in Differentiation of Endothelial Progenitor Cells to Endothelial Cells

As the ability to control the differentiation of endothelial stem/progenitor cells (EPCs) into vascular endothelial cell lineages could be useful for promoting neovascularization, it is important to obtain a deeper understanding of the epigenetic mechanisms that regulate EPC differentiation and neovascularization. Heterochromatin protein 1α (HP1α) is known to be involved in the epigenetic regulation of gene silencing. However, recent reports demonstrate that HP1α can also activate gene expression during cell differentiation. In this study, microarray analysis revealed that HP1α expression was induced during EPC differentiation and is associated with the expression of outgrowing endothelial cell (OEC)-specific protein markers. To explore the role of HP1α in the differentiation of EPCs to OECs, its expression was knocked-down or over-expressed in differentiating EPCs. Overexpression of HP1α promoted the differentiation and angiogenic activity of EPCs in vitro and in vivo, whereas knockdown of HP1α led to a defect in OEC migration, tube formation, and angiogenic sprouting activity. Gene expression profiling showed increased expression of angiogenic genes, including NOTCH1, cadherin-5, and angiopoietin-like-2, and decreased expression of progenitor cell marker genes, including CD133, CXCR4, and C-KIT, in HP1α-overexpressing EPCs. Also, increased HP1α at an early stage of EPC differentiation may regulate angiogenic gene transcription by interacting with chromatin that modifies epigenetic factors such as the methyl-CpG binding domain, Polycomb group ring finger 2, and DNA methyltransferases. Our findings demonstrate, for the first time, that HP1α plays an important role in the differentiation and angiogenic function of EPCs by regulating endothelial gene expression. Stem Cells 2015;33:1512-1522.