Tumor-associated Angiogenesis Research Articles

Phosphoproteomic profiling identifies DNMT1 as a key substrate of beta IV spectrin-dependent ERK/MAPK signaling in suppressing angiogenesis

βIV-spectrin is a membrane-associated cytoskeletal protein that maintains the structural stability of cell membranes and integral proteins such as ion channels and transporters. Its biological functions are best characterized in the brain and heart, although recently we discovered a fundamental new role in the vascular system. Using cellular and genetic mouse models, we reported that βIV-spectrin acts as a critical regulator of developmental and tumor-associated angiogenesis. βIV-spectrin was shown to selectively express in proliferating endothelial cells (EC) and suppress VEGF/VEGFR2 signaling by enhancing receptor internalization and degradation. Here we examined how these events impact the downstream kinase signaling cascades and target substrates. Based on quantitative phosphoproteomics, we found that βIV-spectrin significantly affects the phosphorylation of epigenetic regulatory enzymes in the nucleus, among which DNA methyltransferase 1 (DNMT1) was determined as a top substrate. Biochemical and immunofluorescence results showed that βIV-spectrin inhibits DNMT1 function by activating ERK/MAPK, which in turn phosphorylates DNMT1 at S717 to impede its nuclear localization. Given that DNMT1 controls the DNA methylation patterns genome-wide, and is crucial for vascular development, our findings suggest that epigenetic regulation is a key mechanism by which βIV-spectrin suppresses angiogenesis.

Anti-angiogenic and antitumor effects of anlotinib combined with bevacizumab for colorectal cancer

BackgroundThe progression and metastasis of tumors are typically accompanied by angiogenesis. Crucially, vascular endothelial growth factor (VEGF) and its receptors (VEGFRs) play a significant role in tumor-associated angiogenesis. In this study, the aim was to investigate the antitumor effect of combining bevacizumab (Bev) with anlotinib (An) on colorectal cancer (CRC). MethodsThe CCK-8 assay, EdU assay, and Annexin V staining were conducted to evaluate the proliferation and apoptosis of CRC cells in vitro. The migration capability of CRC cells and HUVECs was assessed using the Transwell assay. Additionally, the tube formation capability of HUVECs was investigated. Furthermore, the antitumor and antiangiogenic effects were evaluated in the BALB/c mice model using immunohistochemistry, TUNEL staining, and 18F-FDG PET/CT imaging. Finally, we analyzed the inhibitory effect of Bev and/or An on related signaling effectors through western blotting. ResultsThe in vivo CRC mice model revealed that the combination of Bev + An significantly suppressed tumor formation and angiogenesis. Bev + An inhibited tumor glucose metabolism and increased the median survival period in tumor-bearing mice. Mechanistically, the expressions of VEGF, VEGFR2, PDGFR, and FGFR, as well as the phosphorylation levels of AKT, were inhibited after Bev+An treatment. In conclusion, the dual vertical targeting of VEGF and VEGFR in the CRC mice model strongly inhibited tumor growth and angiogenesis, with the suppression of the AKT signaling pathway playing a partial role.

Canthin-6-One Inhibits Developmental and Tumour-Associated Angiogenesis in Zebrafish.

Tumour-associated angiogenesis play key roles in tumour growth and cancer metastasis. Consequently, several anti-angiogenic drugs such as sunitinib and axitinib have been approved for use as anti-cancer therapies. However, the majority of these drugs target the vascular endothelial growth factor A (VEGFA)/VEGF receptor 2 (VEGFR2) pathway and have shown mixed outcome, largely due to development of resistances and increased tumour aggressiveness. In this study, we used the zebrafish model to screen for novel anti-angiogenic molecules from a library of compounds derived from natural products. From this, we identified canthin-6-one, an indole alkaloid, which inhibited zebrafish intersegmental vessel (ISV) and sub-intestinal vessel development. Further characterisation revealed that treatment of canthin-6-one reduced ISV endothelial cell number and inhibited proliferation of human umbilical vein endothelial cells (HUVECs), suggesting that canthin-6-one inhibits endothelial cell proliferation. Of note, canthin-6-one did not inhibit VEGFA-induced phosphorylation of VEGFR2 in HUVECs and downstream phosphorylation of extracellular signal-regulated kinase (Erk) in leading ISV endothelial cells in zebrafish, suggesting that canthin-6-one inhibits angiogenesis independent of the VEGFA/VEGFR2 pathway. Importantly, we found that canthin-6-one impairs tumour-associated angiogenesis in a zebrafish B16F10 melanoma cell xenograft model and synergises with VEGFR inhibitor sunitinib malate to inhibit developmental angiogenesis. In summary, we showed that canthin-6-one exhibits anti-angiogenic properties in both developmental and pathological contexts in zebrafish, independent of the VEGFA/VEGFR2 pathway and demonstrate that canthin-6-one may hold value for further development as a novel anti-angiogenic drug.

Modulation of hypoxia-inducible factor-1 signaling pathways in cancer angiogenesis, invasion, and metastasis by natural compounds: a comprehensive and critical review.

Tumor cells employ multiple signaling mediators to escape the hypoxic condition and trigger angiogenesis and metastasis. As a critical orchestrate of tumorigenic conditions, hypoxia-inducible factor-1 (HIF-1) is responsible for stimulating several target genes and dysregulated pathways in tumor invasion and migration. Therefore, targeting HIF-1 pathway and cross-talked mediators seems to be a novel strategy in cancer prevention and treatment. In recent decades, tremendous efforts have been made to develop multi-targeted therapies to modulate several dysregulated pathways in cancer angiogenesis, invasion, and metastasis. In this line, natural compounds have shown a bright future in combating angiogenic and metastatic conditions. Among the natural secondary metabolites, we have evaluated the critical potential of phenolic compounds, terpenes/terpenoids, alkaloids, sulfur compounds, marine- and microbe-derived agents in the attenuation of HIF-1, and interconnected pathways in fighting tumor-associated angiogenesis and invasion. This is the first comprehensive review on natural constituents as potential regulators of HIF-1 and interconnected pathways against cancer angiogenesis and metastasis. This review aims to reshape the previous strategies in cancer prevention and treatment.

Emerging functions and applications of exosomes in oral squamous cell carcinoma.

Oral squamous cell carcinoma is the most common phenotype in pathology, which accounts for 80% of all oral cancers. The therapeutic methods of oral squamous cell carcinoma include surgical excision, chemotherapy, and radiotherapy. Whereas, the high recurrence rate and poor prognosis lead to a 5-year survival rate less than 50%. In order to explore more therapeutic strategies of oral squamous cell carcinoma, the relevant risk factors, mechanisms, and diagnostics are widely detected. The various exosome-mediated biological effects on the development of oral squamous cell carcinoma have drawn lots of attention. Exosomes, a kind of extracellular vesicles secreted from host cells and transferred to other cells, show great potential in the regulations of tumorigenesis, progression, and metastasis on oral squamous cell carcinoma. Moreover, some studies reported that the exosomes could interact with tumor microenvironment and be applied to diagnosis or therapy of oral squamous cell carcinoma. In this work, we will summarize the frontier studies of exosomes in the tumor growth, tumor-associated angiogenesis, invasion, and metastasis of oral squamous cell carcinoma, and then probe the current biological functions and applications of exosomes and exosome-derived materials for the therapeutic strategies of oral squamous cell carcinoma, which would help us to update the understanding of exosomes in oral squamous cell carcinoma.

Beta IV spectrin inhibits the metastatic growth of melanoma by suppressing VEGFR2-driven tumor angiogenesis.

Tumor-associated angiogenesis mediates the growth and metastasis of most solid cancers. Targeted therapies of the VEGF pathways can effectively block these processes but often fail to provide lasting benefits due to acquired resistance and complications. Recently, we discovered βIV -spectrin as a powerful regulator of angiogenesis and potential new target. We previously reported that βIV -spectrin is dynamically expressed in endothelial cells (EC) to induce VEGFR2 protein turnover during development. Here, we explored how βIV -spectrin influences the tumor vasculature using the murine B16 melanoma model and determined that loss of EC-specific βIV -spectrin dramatically promotes tumor growth and metastasis. Intraperitoneally injected B16 cells formed larger tumors with increased tumor vessel density and greater propensity for metastatic spread particularly to the chest cavity and lung compared to control mice. These results support βIV -spectrin as a key regulator of tumor angiogenesis and a viable vascular target in cancer.

Emerging role of exosome-derived non-coding RNAs in tumor-associated angiogenesis of tumor microenvironment.

The tumor microenvironment (TME) is an intricate ecosystem that is actively involved in various stages of cancer occurrence and development. Some characteristics of tumor biological behavior, such as proliferation, migration, invasion, inhibition of apoptosis, immune escape, angiogenesis, and metabolic reprogramming, are affected by TME. Studies have shown that non-coding RNAs, especially long-chain non-coding RNAs and microRNAs in cancer-derived exosomes, facilitate intercellular communication as a mechanism for regulating angiogenesis. They stimulate tumor growth, as well as angiogenesis, metastasis, and reprogramming of the TME. Exploring the relationship between exogenous non-coding RNAs and tumor-associated endothelial cells, as well as their role in angiogenesis, clinicians will gain new insights into treatment as a result.

TRAF2 promotes M2-polarized tumor-associated macrophage infiltration, angiogenesis and cancer progression by inhibiting autophagy in clear cell renal cell carcinoma

BackgroundThe management of advanced clear cell renal cell carcinoma (ccRCC) remains a major challenge in clinical practice, and the construction of more reliable prognostic prediction models and the further elucidation of key molecular mechanisms of tumor progression are topics in urgent need of in-depth investigation.MethodsWe used CIBERSORT to estimate the proportion of 22 tumor-infiltrating immune cell types in the TCGA-KIRC cohort. Weighted gene co-expression network analysis, least absolute shrinkage and selection operator regression analysis were used to build risk prediction models. Expression patterns and clinical significance of TRAF2 were determined through bioinformatics analysis, real-time qPCR, Western Blot, immunohistochemistry. GSEA analysis, transmission electron microscopy, 2D/3D colony formation assay, cell migration and invasion assay, and tube-formation assay were used to investigate the underlying function and mechanism of the TRAF2/M2 macrophage/autophagy axis.ResultsWe constructed a novel prognostic prediction model based on M2 macrophage-related genes, which was identified as an accurate, independent and specific prognostic risk model for ccRCC patients. A reliable nomogram was constructed to predict 1-, 3-, and 5-year overall survival for patients with ccRCC. As one of the constituent genes of the risk model, TRAF2 was determined to be upregulated in ccRCC and associated with poor clinical prognosis. We found that TRAF2 promotes malignant progression of ccRCC by regulating macrophage polarization, migration and angiogenesis. Mechanistically, we found that TRAF2 promotes the polarization of M2 macrophages, and this chemotaxis is achieved in an autophagy-dependent pathway. Orthotopic tumor growth assay results revealed that TRAF2 plays a key role as a promotor of ccRCC growth and metastasis.ConclusionsIn conclusion, this risk model is highly predictive of prognostic in ccRCC patients, which is expected to promote improved treatment evaluation and comprehensive management of ccRCC. Moreover, our findings reveal that the TRAF2/M2 macrophage/autophagy axis plays a key regulatory role in the malignant progression of ccRCC, and suggest that TRAF2 is a potential novel therapeutic target for advanced ccRCC.

Benefits of β-blockers in cancer treatment

Cancer is one of the leading causes of death in the world. Researchers keep attempting to develop therapy modalities to decrease the mortality and morbidity of cancer patients by trying to comprehend the effect of sympathetic nerves (through catecholamine and adrenergic receptors) in cancer development. Catecholamine activation in β-adrenergic receptors (β1-AR, β2-AR, and β3-AR) may influence cytokine and cancer immunity system, initiate tumorigenesis, stimulate tumor-associated macrophage and angiogenesis, influence tumor microenvironment, and facilitate cancer cell metastasis, leading to increased progressivity of cancer cells. β-blockers may inhibit catecholamine on β-AR and various types of paths needed for cancer cells to develop. β-blockers also stimulate cancer cell apoptosis, decrease pro-inflammatory mediators and growth factors of cancer cells. In addition, β-blockers also have benefits as supplementary cancer therapy, increase chemoradiotherapy sensitivity, decrease cardiotoxicity, and improve cancer cachexia. The benefits of β-blockers are expected to reduce morbidity and increase the survival rates of cancer patients. This review comprehensively assesses the benefit of b-blockers as a part of the complete management of cancer patients.

Abstract 4604: Effect of CDK 4/6 inhibition on anti-angiogenesis effect in gastric cancer

Abstract Angiogenesis, a hallmark of cancer, is a phenomenon in which new blood vessels are created from existing blood vessels. As the tumor grows, they secrete ligands such as vascular endothelial growth factor (VEGF). Therefore, anti-tumor effect could be achieved by preventing tumor-associated angiogenesis. In previous reports, CDK4/6 has been acknowledged to regulate VEGF transcription in addition to cell cycle regulation. There are few studies explaining the angiogenesis-related effects of CDK4/6 inhibitors in gastric cancer (GC). In this study, we aim to verify the anti-angiogenesis effect through CDK4/6 inhibition. First, we confirmed proliferation and angiogenesis in endothelial cells. Next, the change in VEGF expression induced by CDK4/6 inhibitor in GC cell lines was investigated. In-vitro angiogenesis research was conducted using human umbilical vein endothelial cells (HUVEC). Abemaciclib was used as a CDK4/6 inhibitor. To determine the efficacy of abemaciclib, HUVEC was treated with abemaciclib for 3 days and cell viability was assessed by CCK-8 assay. IC50 value was determined by the CalcuSyn software. Furthermore, tube formation assay, wound healing assay, cell cycle analysis and SA-β-gal assay were performed to explore effect of abemaciclib on HUVEC. VEGF-A expression was evaluated by ELISA. First, we identified direct anti-angiogenesis effect of abemaciclib on HUVEC. The IC50 value was 1.28 μM. At clinically achievable concentrations of abemaciclib (Cmax, 0.5 μM), HUVEC only showed a 20% growth inhibition. Abemaciclib did not suppress tube formation and migratory potential of HUVECs. However, abemaciclib induced a G1 arrest in HUVEC after 0.5 μM abemaciclib treatment for 24hr. To ensure whether the increase in the number of G1 phase cells is due to senescence, SA-β-gal assay was performed. The levels of SA-β-gal-positive cell staining in abemaciclib-treated group were higher than control, suggesting that abemaciclib induced cell senescence on HUVEC. While our results suggested that CDK4/6 inhibitor did not show direct anti-angiogenic effect on endothelial cells, we studied indirect anti-angiogenesis effect of abemaciclib in GC cell lines through regulation of VEGF transcription. Conditioned media of 49 GC cell lines had a wide range of VEGF secretion ranged from 0.146 to 22.676 ng/mL. (ave. 4.07 ng/mL). We have set the cut off of secreted VEGF as 10 ng/mL, at which angiogenesis can be induced. There were four cell lines (4/49, 8.2%) whose VEGF concentrations were more than the angiogenesis-inducing VEGF concentration (10 ng/mL). Interestingly, 3 of these 4 GC cell lines demonstrated a decrease in VEGF secretion, following 0.5 μM abemaciclib treatment. In conclusion, we did not observe inhibition of angiogenesis in HUVEC. However, CDK4/6 inhibition can cause senescence in HUVEC, inhibit tumor growth, and indirectly induce anti-angiogenic effects in gastric cancer. Citation Format: Sang Woo Cho, Woo Sun Kwon, Tae Soo Kim, Juin Park, Eun Seo Kim, Hyun Cheol Chung, Sun Young Rha. Effect of CDK 4/6 inhibition on anti-angiogenesis effect in gastric cancer. [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 4604.

Breast cancer cell secretome analysis to decipher miRNA regulating the tumor microenvironment and discover potential biomarkers

MicroRNA (miRNA/miR) 526 b- and miR655-overexpressed tumor cell-free secretions regulate the breast cancer tumor microenvironment (TME) by promoting tumor-associated angiogenesis, oxidative stress, and hypoxic responses. Additionally, premature miRNA (pri-miR526b and pri-miR655) are established breast cancer blood biomarkers. However, the mechanisms of how these miRNAs regulate the TME has yet to be investigated. Mass spectrometry analysis of miRNA-overexpressed cell lines MCF7-miR526b, MCF7-miR655, and miRNA-low MCF7-Mock cell-free secretomes identified 34 differentially expressed proteins coded by eight genes. In both miRNA-high cell secretomes, four markers are upregulated: YWHAB, SFN, TXNDC12, and MYL6B, and four are downregulated: PEA15, PRDX4, PSMB6, and FN1. All upregulated marker transcripts are significantly high in both total cellular RNA pool and cell-free secretions of miRNA-high cell lines, validated with quantitative RT-PCR. Bioinformatics tools were used to investigate these markers' roles in breast cancer. These markers' top gene ontology functions are related to apoptosis, oxidative stress, membrane transport, and motility supporting oncogenic miR526b- and miR655-induced functions. Gene transcription factor analysis tools were used to show how these miRNAs regulate the expression of each secretory marker. Data extracted from the Human Protein Atlas showed that YWHAB, SFN, and TXNDC12 expression could distinguish early and late-stage breast cancer in various breast cancer subtypes and are associated with poor patient survival. Additionally, immunohistochemistry analysis showed the expression of each marker in breast tumors. A stronger correlation between miRNA clusters and upregulated secretory markers gene expression was found in the luminal A tumor subtype. YWHAB, SFN, and MYL6B are upregulated in breast cancer patient's blood, showing biomarker potential. Of these identified novel miRNA secretory markers, SFN and YWHAB successfully passed all validations and are the best candidates to further investigate their roles in miRNA associated TME regulation. Also, these markers show the potential to serve as blood-based breast cancer biomarkers, especially for luminal-A subtypes.

Multi-omics profiling and digital image analysis reveal the potential prognostic and immunotherapeutic properties of CD93 in stomach adenocarcinoma.

Recent evidence highlights the fact that immunotherapy has significantly improved patient outcomes. CD93, as a type I transmembrane glycoprotein, was correlated with tumor-associated angiogenesis; however, how CD93 correlates with immunotherapy in stomach adenocarcinoma (STAD) remains unclear. TCGA, GTEx, GEO, TIMER2.0, HPA, TISIDB, TCIA, cBioPortal, LinkedOmics, and ImmuCellAI public databases were used to elucidate CD93 in STAD. Visualization and statistical analysis of data were performed by R (Version 4.1.3), GraphPad (Version 8.0.1), and QuPath (Version 0.3.2). CD93 was highly expressed in STAD compared with adjacent normal tissues. The overexpression of CD93 was significantly correlated with a poor prognosis in STAD. There was a negative correlation between CD93 expression levels with CD93 mutation and methylation in STAD. Our results revealed that CD93 expression was positively associated with most immunosuppressive genes (including PD-1, PD-L1, CTLA-4, and LAG3), immunostimulatory genes, HLA, chemokine, and chemokine receptor proteins in STAD. Furthermore, in STAD, CD93 was noticeably associated with the abundance of multiple immune cell infiltration levels. Functional HALLMARK and KEGG term enhancement analysis of CD93 through Gene Set Enrichment Analysis was correlated with the process of the angiogenesis pathway. Subsequently, digital image analysis results by QuPath revealed that the properties of CD93+ cells were statistically significant in different regions of stomach cancer and normal stomach tissue. Finally, we utilized external databases, including GEO, TISIDB, ImmuCellAI, and TCIA, to validate that CD93 plays a key role in the immunotherapy of STAD. Our study reveals that CD93 is a potential oncogene and is an indicative biomarker of a worse prognosis and exerts its immunomodulatory properties and potential possibilities for immunotherapy in STAD.

Inhibition of Non-small Cell Lung Cancer by Ferroptosis and Apoptosis Induction through P53 and GSK-3β/Nrf2 Signal Pathways using Qingrehuoxue Formula.

This study aimed to elucidate the effects of Qingrehuoxue Formula (QRHXF) on NSCLC and its underlying mechanisms. Nude mouse model of subcutaneous tumors was established. QRHXF and erastin were administered orally and intraperitoneally, respectively. Mice's body weight and subcutaneous tumor volumes were measured. The effects of QRHXF on epithelial-mesenchymal transition (EMT), tumor-associated angiogenesis and matrix metalloproteinases (MMPs) were assessed. Importantly, we also analysed the anti-NSCLC of QRHXF form the aspect of ferroptosis and apoptosis and investigate its underlying mechanisms. The safety of QRHXF in mice was also evaluated. QRHXF slowed down the speed of tumor growth and visibly inhibited tumor growth. The expression levels of CD31, VEGFA, MMP2 and MMP9 were prominently suppressed by QRHXF. Furthermore, QRHXF appeared to remarkably inhibite cell proliferation and EMT by decreasing Ki67, N-cadherin and vimentin expression but elevating E-cadherin expression. There were more apoptotic cells in QRHXF group's tumor tissues, and QRHXF treatment increased BAX and cleaved-caspased 3 levels but decreased Bcl-2 levels. QRHXF significantly increased the accumulation of ROS, Fe2+, H2O2, and MDA while reduced GSH levels. SLC7A11 and GPX4 protein levels were considerably suppressed by QRHXF treatment. Moreover, QRHXF triggered ultrastructural changes in the mitochondria of tumor cells. The levels of p53 and p-GSK-3β were upregulated, whereas that of Nrf2 was downregulated in the groups treated with QRHXF. QRHXF displayed no toxicity in mice. QRHXF activated ferroptosis and apoptosis to suppress NSCLC cell progression via p53 and GSK-3β/Nrf2 signaling pathways.

Exosomal miR-30a-5p promoted intrahepatic cholangiocarcinoma progression by increasing angiogenesis and vascular permeability in PDCD10 dependent manner.

Tumor-associated angiogenesis positively associates with malignant metastasis of intrahepatic cholangiocarcinoma (ICCA). Cancer cell-derived exosomes carrying microRNAs involves in tumor microenvironment (TME) regulation. We aimed to evaluate exosomal miR-30a-5p in ICCA development. Our data showed that increased miR-30a-5p level was correlated with higher microvascular density (MVD) and worse prognosis. Augmented miR-30a-5p expression was induced by hypoxia induced factor 1α (HIF-1α) in ICCA cell. Further exploration revealed that ICCA-derived miR-30a-5p could be transferred to endothelial and increased endothelial cells recruitment and proliferation, induced angiogenesis and vascular permeability in exosome dependent manner. In addition, circulating exosomal miR-30a-5p was higher in ICCA patients, and correlated with ICCA tissues-expressing miR-30a-5p. Hypoxic stress enhanced the effects of exosomal miR-30a-5p on endothelial-associated phenotypes. Rescued experiments showed that exosomal miR-30a-5p modulated endothelial-associated phenotypes in a way relied on programmed cell death 10 (PDCD10). Moreover, we revealed that the packing of miR-30a-5p into ICCA cells-derived exosomes was mediated by eukaryotic translation initiation factor 4B (EIF4B). More importantly, the combined application of targeting miR-30a-5p and apatinib could synergistically improve antiangiogenic efficacy in ICCA. Combined, ICCA-derived exosomal miR-30a-5p could be an excellent therapeutic and monitoring indicator for ICCA patients.

Abstract B031: PRC2 inhibitor suppresses angiogenesis in Hepatocellular carcinoma (HCC) by up-regulation of anti-angiogenic factors vasohibin1 (VASH1) and tissue inhibitor of metalloproteinases 3 (TIMP-3)

Abstract Tumor-associated angiogenesis plays a crucial role in the progression of tumor, especially in highly vascularized cancer, such as Liver hepatocellular carcinoma (LIHC), ovarian cancer, lung cancer, human head and neck cancers. Clinical research has shown that LIHC cells upregulate expression of vascular endothelial growth factor A (VEGFA), and induce proliferation and migration of epithelial cells under hypoxia condition, however, the mechanism of angiogenesis has not been completely elucidated in LIHC, especially in epigenetic regulation level. Polycomb repressive complex 2 (PRC2) is a multi-subunit protein complex that catalyzes the methylation of histone H3 at lysine 27, Enhancer of Zeste homolog 2 (EZH2) is the catalytic subunit, while embryonic ectoderm development (EED) recognizes H3K27me3 and enhance the catalytic activity of EZH2. A recent study suggests PRC2 promote angiogenesis in human ovarian carcinoma, while the detailed mechanism this process has not been illustrated. In this paper, we show BR1763, a potent, selective and orally bioavailable small-molecule inhibitor of EED, inhibits PRC2 activity, promote expression of vasohibin1 (VASH1) and tissue inhibitor of metalloproteinases 3 (TIMP3) in certain Hepatocellular Carcinoma (HCC) cells, and induces tumor growth inhibition by suppression of tumor-associated angiogenesis in vivo. Citation Format: Hailong Zhang. PRC2 inhibitor suppresses angiogenesis in Hepatocellular carcinoma (HCC) by up-regulation of anti-angiogenic factors vasohibin1 (VASH1) and tissue inhibitor of metalloproteinases 3 (TIMP-3). [abstract]. In: Proceedings of the AACR Special Conference: Cancer Epigenomics; 2022 Oct 6-8; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2022;82(23 Suppl_2):Abstract nr B031.

Adrenomedullin Secreted by Melanoma Cells Promotes Melanoma Tumor Growth through Angiogenesis and Lymphangiogenesis

Metastatic melanoma is an aggressive tumor and can constitute a real therapeutic challenge despite the significant progress achieved with targeted therapies and immunotherapies, thus highlighting the need for the identification of new therapeutic targets. Adrenomedullin (AM) is a peptide with significant expression in multiple types of tumors and is multifunctional. AM impacts angiogenesis and tumor growth and binds to calcitonin receptor-like receptor/receptor activity-modifying protein 2 or 3 (CLR/RAMP2; CLR/RAMP3). In vitro and in vivo studies were performed to determine the functional role of AM in melanoma growth and tumor-associated angiogenesis and lymphangiogenesis. In this study, AM and AM receptors were immunohistochemically localized in the tumoral compartment of melanoma tissue, suggesting that the AM system plays a role in melanoma growth. We used A375, SK-MEL-28, and MeWo cells, for which we demonstrate an expression of AM and its receptors; hypoxia induces the expression of AM in melanoma cells. The proliferation of A375 and SK-MEL-28 cells is decreased by anti-AM antibody (αAM) and anti-AMR antibodies (αAMR), supporting the fact that AM may function as a potent autocrine/paracrine growth factor for melanoma cells. Furthermore, migration and invasion of melanoma cells increased after treatment with AM and decreased after treatment with αAMR, thus indicating that melanoma cells are regulated by AM. Systemic administration of αAMR reduced neovascularization of in vivo Matrigel plugs containing melanoma cells, as demonstrated by reduced numbers of vessel structures, which suggests that AM is one of the melanoma cells-derived factors responsible for endothelial cell-like and pericyte recruitment in the construction of neovascularization. In vivo, αAMR therapy blocked angiogenesis and lymphangiogenesis and decreased proliferation in MeWo xenografts, thereby resulting in tumor regression. Histological examination of αAMR-treated tumors showed evidence of the disruption of tumor vascularity, with depletion of vascular endothelial cells and a significant decrease in lymphatic endothelial cells. The expression of AM by melanoma cells promotes tumor growth and neovascularization by supplying/amplifying signals for neoangiogenesis and lymphangiogenesis.

YKL-39 is an independent prognostic factor in gastric adenocarcinoma and is associated with tumor-associated macrophage infiltration and angiogenesis

BackgroundGastric cancer has a high incidence and mortality rate. Angiogenesis is necessary for tumor infiltration and metastasis and affects patient prognosis. YKL-39 has monocyte chemotactic activity and pro-angiogenic activity in some tumors. In this study, we investigated the relationship between YKL-39 and tumor-associated macrophages and microangiogenesis in gastric cancer to determine its potential as a prognostic biomarker.Materials and methodsA total of 119 patients with gastric cancer who had undergone gastrectomy at the 940th Hospital of the Joint Security Force between 2014 and 2018 were included in this study. We assayed the protein expression of YKL-39, CD68, and CD34 by immunohistochemistry in tissues of 119 patients with gastric cancer, as well as the intracellular expression of YKL-39 and CD68 by immunofluorescence. Data were analyzed with SPSS Statistics 25.0 to explore the impact of expression of YKL-39, CD68, and CD34 in gastric cancer patients and the relationship among them.ResultsOur results show that YKL-39 was expressed in both the nucleus and cytoplasm of gastric cancer cells and tumor mesenchyme. YKL-39 protein expression was associated with the depth of tumor infiltration, lymph node metastasis, and TNM stage; CD68 protein expression was associated with lymph node metastasis and TNM stage; CD34 protein expression was not associated with clinicopathological characteristics. Expression of YKL-39 was positively correlated with CD68 and CD34 (p < 0.001), and high expression of YKL-39 was associated with poor prognosis (p < 0.05).ConclusionIn gastric cancer, YKL-39 expression is positively correlated with the degree of tumor-associated macrophage infiltration and angiogenesis, and is a potential prognostic marker for gastric cancer.

The Anti-Vascular Endothelial Growth Factor Receptor 1 (VEGFR-1) D16F7 Monoclonal Antibody Inhibits Melanoma Adhesion to Soluble VEGFR-1 and Tissue Invasion in Response to Placenta Growth Factor.

Placenta growth factor (PlGF) is a member of the vascular endothelial growth factor (VEGF) family involved in tumor-associated angiogenesis and melanoma invasion of the extra-cellular matrix (ECM) through activation of membrane VEGF receptor 1 (VEGFR-1). A soluble VEGFR-1 (sVEGFR-1) form is released in the ECM, where it sequesters proangiogenic factors and stimulates endothelial or tumor cell adhesion and chemotaxis through interaction with α5β1 integrin. The anti-VEGFR-1 monoclonal antibody (D16F7 mAb) inhibits VEGF-A or PlGF-mediated signal transduction without affecting ligand interaction, thus preserving sVEGFR-1 decoy function. The aim of this study was to investigate whether D16F7 mAb hampers melanoma spread by in vitro analysis of cell adhesion to sVEGFR-1, ECM invasion, transmigration through an endothelial cell monolayer and in vivo evaluation of tumor infiltrative potential in a syngeneic murine model. Results indicate that D16F7 mAb significantly inhibits melanoma adhesion to sVEGFR-1 and ECM invasion, as well as transmigration in response to PlGF. Moreover, treatment of melanoma-bearing mice with the anti-VEGFR-1 mAb not only inhibits tumor growth but also induces a significant reduction in bone infiltration associated with a decrease in PlGF-positive melanoma cells. Furthermore, D16F7 mAb reduces PlGF production by melanoma cells. Therefore, blockade of PLGF/VEGFR-1 signaling represents a suitable strategy to counteract the metastatic potential of melanoma.

Listeria-based immunotherapy directed against CD105 exerts anti-angiogenic and anti-tumor efficacy in renal cell carcinoma

Targeting tumor-associated angiogenesis is currently at the forefront of renal cell carcinoma (RCC) therapy, with sunitinib and bevacizumab leading to increased survival in patients with metastatic RCC (mRCC). However, resistance often occurs shortly after initiation of therapy, suggesting that targeting the tumor-associated vascular endothelium may not be sufficient to eradicate RCC. This study reports the therapeutic efficacy of a Listeria (Lm)-based vaccine encoding an antigenic fragment of CD105 (Lm-LLO-CD105A) that targets both RCC tumor cells and the tumor-associated vasculature. Lm-LLO-CD105A treatment reduced primary tumor growth in both subcutaneous and orthotopic models of murine RCC. The vaccine conferred anti-tumor immunity and remodeled the tumor microenvironment (TME), resulting in increased infiltration of polyfunctional CD8+ and CD4+ T cells and reduced infiltration of immunosuppressive cell types within the TME. We further provide evidence that the therapeutic efficacy of Lm-LLO-CD105A is mediated by CD8+ T cells and is dependent on the robust antigenic expression of CD105 by RCC tumor cells. The result from this study demonstrates the safety and promising therapeutic efficacy of targeting RCC-associated CD105 expression with Lm-based immunotherapy.

Squalamines in Blockade of Tumor-Associated Angiogenesis and Cancer Progression.

Simple SummaryDespite the many ongoing advances in cancer prevention, diagnosis and clinical management, global mortality from human cancers remains at high levels. Notably, more effective treatment of many cancers is advancing due to introduction of novel biologic therapies targeted to tumor signaling and immunologic pathways. Tumor growth is dependent on a sustained blood supply of nutrients and oxygen, and this process termed tumor-associated angiogenesis (TAA) has prognostic and therapeutic importance in several human malignancies. This review addresses use of squalamines to stop tumor growth. This naturally occurring compound can inhibit angiogenesis in tumors thereby reducing malignant progression in preclinical studies and in early clinical trials.Mechanisms of action of squalamine in human vascular endothelial cells indicate that this compound attaches to cell membranes, potentially interacting with calmodulin, Na+/H+ exchanger isoform NHE3 and other signaling pathways involved in the angiogenic process. Thus, squalamine elicits blockade of VEGF-induced endothelial tube-like formation in vitro. Further, squalamine reduces growth of several preclinical models of human cancers in vivo and acts to stop metastatic tumor spread, actions due largely to blockade of angiogenesis induced by the tumor and tumor microenvironment. Squalamine in Phase I/II trials, alone or combined with standard care, shows promising antitumor activity with limited side-effects in patients with advanced solid cancers. Increased attention on squalamine regulation of signaling pathways with or without combination treatments in solid malignancies deserves further study.