Tumor-associated Angiogenesis Research Articles

Tumour-associated Angiogenesis and Intermediate Blood Vessels in Renal Cell Carcinoma.

Renal cell carcinoma is strongly vascularized, and formation of new blood vessels is a complex and multi-step process. In this study, we analysed the subtypes of intermediate blood vessels, as shown by double immunohistochemistry. Tumour-associated blood vessels were identified by double immunostaining based on CD34 and smooth muscle cell actin. Blood vessels were classified both quantitatively and qualitatively based on the expression of the aforementioned two markers. The main criteria to sub-classify intermediate blood vessels was the presence, distribution, and arrangement of perivascular cells. We described three subtypes of intermediate blood vessels found particularly in the tumour area: Subtype 1 lacked perivascular cells, subtype 2 showed scattered pericytes attached to the vascular wall, and subtype 3 showed a continuous layer of perivascular cells on one side. We describe for the first time three subtypes of renal cell carcinoma-associated intermediate blood vessels, which could be important in prognosis and as potential targets for anti-vascular therapy.

Targeting HDL in tumor microenvironment: New hope for cancer therapy.

Epidemiological studies have shown that plasma HDL-C levels are closely related to the risk of prostate cancer, breast cancer, and other malignancies. As one of the key carriers of cholesterol regulation, high-density lipoprotein (HDL) plays an important role in tumorigenesis and cancer development through anti-inflammation, antioxidation, immune-modulation, and mediating cholesterol transportation in cancer cells and noncancer cells. In addition, the occurrence and progression of cancer are closely related to the alteration of the tumor microenvironment (TME). Cancer cells synthesize and secrete a variety of cytokines and other factors to promote the reprogramming of surrounding cells and shape the microenvironment suitable for cancer survival. By analyzing the effect of HDL on the infiltrating immune cells in the TME, as well as the relationship between HDL and tumor-associated angiogenesis, it is suggested that a moderate increase in the level of HDL in vivo with consequent improvement of the function of HDL in the TME and induction of intracellular cholesterol efflux may be a promising strategy for cancer therapy.

In vivo preclinical assessment of novel 68Ga-labelled peptides for imaging of tumor associated angiogenesis using positron emission tomography imaging

Formation and growth of metastases require a new vascular network. Angiogenesis plays an essential role in the expansion and progression of most malignancies. A high number of molecular pathways regulate angiogenesis, including vascular endothelial growth factor (VEGF), αvβ3 integrin, matrix metalloproteinases (MMPs), or aminopeptidase N. The aim of this study is to involve new, easily accessible peptide sequences into the of neo-angiogenesis in malignant processes. Labelling of these peptide ligands with 68Ga enable PET imaging of neo-vascularization.

Potential of peptide-engineered exosomes with overexpressed miR-92b-3p in anti-angiogenic therapy of ovarian cancer.

IntroductionExosomal microRNA (miRNA) as a mediator of intercellular communication plays an essential part in tumor‐relevant angiogenesis. Therapy against angiogenesis has been demonstrated to have a remarkable antitumor efficacy in various malignancies, but not as expected in ovarian cancer.MethodsExosomes were isolated by ultracentrifugation. Exosomal miRNA sequencing and gene function experiments were used to identify the differential expressed miRNAs in exosomes and their mRNA targets. SKOV3 cell line that stably overexpressed miR‐92b‐3p was constructed by lentivirus. In vitro, angiogenesis was analyzed by tube formation assay and migration assay. The angiogenic and antitumor effects in vivo were assessed in zebrafish and nude mouse models. Combination index was calculated to assess the synergetic inhibition of angiogenesis between miR‐92b‐3p and Apatinib. Peptides were conjugated with exosomal membranes to obtain engineered exosomes.ResultsOvarian cancer cell‐derived exosomes facilitated the angiogenesis and migration capability of vascular endothelial cells in vitro and in vivo. The expression of miR‐92b‐3p was much lower in ovarian cancer cell‐derived exosomes than that in immortalized ovarian epithelial cell‐derived exosomes. The exosomal miR‐92b‐3p modulated tumor‐associated angiogenesis via targeting SOX4. Besides, Peptide‐engineered exosomes with overexpressed miR‐92b‐3p showed the stronger abilities of anti‐angiogenesis and antitumor than parental exosomes, whether alone or combined with Apatinib.ConclusionsOur findings demonstrate the effect and mechanism of exosomal miR‐92b‐3p from ovarian cancer cells on tumor‐associated angiogenesis and the potential of artificially generated exosomes with overexpressed miR‐92b‐3p to be used as anti‐angiogenic agent, which may provide a new approach for anti‐angiogenic therapy of ovarian cancer.

Subcellular Colocalization of Rho GTPase TCL with Rab Family GTPases

TCL (RhoJ) belongs to the Rho family of GTPases and contributes to tumor-associated angiogenesis. Understanding its basic cell biology is essential for establishing its role in this process. Experiments in several labs have shown plasma membrane and vesicular localizations of TCL, but it is unknown where the GTPase may function in vesicle trafficking. To better understand this aspect of TCL cellular biology, a YFP-tagged version TCL will be separately co-expressed in HeLa cells with twelve different mCherry-tagged versions of Rab GTPases. Images will be captured using an Olympus Fluoview confocal microscope and colocalization assessed both qualitatively and quantitatively using CellSens software. Since many of the Rab GTPases have established vesicular localizations, we hypothesize that analyzing the colocalization of tagged Rabs and TCL will help establish specific vesicular localization patterns of TCL.

Cancer Stem Cells and Neovascularization.

Cancer stem cells (CSCs) refer to a subpopulation of cancer cells responsible for tumorigenesis, metastasis, and drug resistance. Increasing evidence suggests that CSC-associated tumor neovascularization partially contributes to the failure of cancer treatment. In this review, we discuss the roles of CSCs on tumor-associated angiogenesis via trans-differentiation or forming the capillary-like vasculogenic mimicry, as well as the roles of CSCs on facilitating endothelial cell-involved angiogenesis to support tumor progression and metastasis. Furthermore, we discuss the underlying regulation mechanisms, including the intrinsic signals of CSCs and the extrinsic signals such as cytokines from the tumor microenvironment. Further research is required to identify and verify some novel targets to develop efficient therapeutic approaches for more efficient cancer treatment through interfering CSC-mediated neovascularization.

Icariside II: Anticancer Potential and Molecular Targets in Solid Cancers.

Icariside II, an active flavonoid, is extracted from the traditional Chinese medicinal herb Epimedii. It possesses multiple biological and pharmacological properties, including anti-inflammatory, anticancer, and anti-osteoporotic properties. In recent years, apoptosis has become the hot spot in anticancer therapies. Icariside II exerts positive effects on inducing apoptosis and inhibiting proliferation in various cancers. The antitumorigenic activity of Icariside II was also proven through cell cycle arrest, triggering autophagy, reducing cellular metabolism, and inhibiting cancer metastasis and tumor-associated angiogenesis. Additionally, Icariside II, as a natural product, contributed to a synergistic effect alongside chemotherapeutic drugs. Due to its poor aqueous solubility and permeability, more strategies were developed to improve its therapeutic effects. This review aimed to summarize the chemopreventive properties of Icariside II in solid tumors and reveal its underlying molecular mechanisms.

Role of tumor-associated macrophages in relation to angiogenesis in urothelial bladder carcinoma

Background: Urothelial Bladder carcinoma is an aggressive tumor with male predominance. The tumor microenvironment is found to affect tumor progression and biology. One of its main constituents is tumor-associated- macrophages (TAMs). Angiogenesis is a powerful factor in the development of many tumors and is supposed to be induced by tumor cells and some stromal components that regulate tumor behavior. Aim: To assess the correlation of TAMs and angiogenesis in the stroma of urothelial carcinoma and its correlation with the tumor grade and stage and nodal metastasis. Material and Methods: This study was carried out on 30 paraffin blocks of bladder urothelial carcinoma. Hematoxylin and eosin staining was done for confirmation of the histopathological diagnosis. Immunohistochemical staining by CD68 antibody was done for counting of TAMs and CD34 antibodies for tumor-associated angiogenesis (microvessel count). Results: Significant higher TAMs count was detected in high-grade and invasive bladder cancers compared to low-grade and non-invasive types and in patients with nodal metastasis. Moreover, microvessel counts (MVCs) were significantly higher in higher grade, invasive bladder cancers and in patients with nodal metastasis. There was a positive correlation between the predominance of CD68+ TAMs and CD34+ MVCs in urothelial carcinoma. Conclusion: There is a positive correlation between TAMs and angiogenesis in the stroma of urothelial carcinoma and both are positively correlated with tumor grade, stage, and nodal metastasis. Our data indicated that both TAMs and MVCs could serve as prognostic markers for urothelial bladder cancer.

The role of angiotensin-(1-7) on acquired platinum resistance-induced angiogenesis in non-small cell lung cancer in vitro and in vivo.

Renin-angiotensin system (RAS) signaling has been implicated in the development of cancer. The new RAS ACE2/Ang-(1-7)/Mas axis antagonizes the classical ACE/Ang II/AT1R axis. Ang-(1-7) has pleiotropic roles in lung cancer including suppressing proliferation, angiogenesis, and metastasis. This research was designed to investigate the effect of Ang-(1-7) on tumor-associated angiogenesis in DDP-resistant lung cancer cell lines. We first established acquired DDP-resistant cell lines A549 (A549-DDP) and LLC (LLC-DDP). We next performed RT-qPCR, western blot, ELISA, tube formation, microvessel density detection, immunohistochemistry, and tumor formation assays. The results showed that the mRNA and protein levels of RAS components and vascular endothelial growth factor A (VEGFa) were lessened in the A549/LLC-DDP+Ang-(1-7) group compared with the A549/LLC-DDP group. This effect could be blocked by the MAS receptor antagonist A779. The data revealed that Ang-(1-7) could perform its antiangiogenic function by PI3K/AKT and MAPK pathways. Furthermore, the impact of Ang-(1-7) on tumor-associated angiogenesis has been confirmed in lung cancer xenograft model with acquired DDP resistance. These results provide a theoretical basis for designing therapeutic strategies for targeting Ang-(1-7) in the treatment of NSCLC.

Diagnostic Value of VEGF-A, VEGFR-1 and VEGFR-2 in Feline Mammary Carcinoma.

Vascular endothelial growth factor (VEGF-A) plays an essential role in tumor-associated angiogenesis, exerting its biological activity by binding and activating membrane receptors, as vascular endothelial growth factor receptor 1 and 2 (VEGFR-1, VEGFR-2). In this study, serum VEGF-A, VEGFR-1, and VEGFR-2 levels were quantified in 50 cats with mammary carcinoma and 14 healthy controls. The expression of these molecules in tumor-infiltrating lymphocytes (TILs) and in cancer cells was evaluated and compared with its serum levels. Results obtained showed that serum VEGF-A levels were significantly higher in cats with HER2-positive and Triple Negative (TN) Normal-Like subtypes, when compared to control group (p = 0.001, p = 0.020). Additionally, serum VEGFR-1 levels were significantly elevated in cats presenting luminal A, HER2-positive and TN Normal-Like tumors (p = 0.011, p = 0.048, p = 0.006), as serum VEGFR-2 levels (p = 0.010, p = 0.046, p = 0.005). Moreover, a positive interaction was found between the expression of VEGF-A, VEGFR-1, and VEGFR-2 in TILs and their serum levels (p = 0.002, p = 0.003, p = 0.003). In summary, these findings point to the usefulness of VEGF-A and its serum receptors assessment in clinical evaluation of cats with HER2-positive and TN Normal-Like tumors, suggesting that targeted therapies against these molecules may be effective for the treatment of these animals, as described in human breast cancer.

Targeting Neuregulin 1 (NRG1): A Novel Biomarker for Non-Small-Cell Lung Cancer.

The aim of this study was to identify the roles of neuregulin 1 (NRG1) during the tumor progression in non-small-cell lung cancer (NSCLC). NSCLC patients with lung squamous cell carcinoma and lung adenocarci-noma were enrolled in this study. The expression of NRG1, vascular endothelial growth factor (VEGF) and surviving in clinical specimens was examined using immunohistochemistry analysis. The cytokine production in plasma was evaluated by ELISA. The levels of NRG1-associated molecules were determined using western blotting. The proliferation and apoptosis of cells with NRG1 knockdown were accessed by CCK-8 assay and flow cytometry. Upregulation of NRG1 as well as tumor-associated angiogenesis markers VEGF and survivin was detected in tissue and serum samples of NSCLC patients compared with the control. Furthermore, positive correlation with NSCLC levels and VEGF/survivin was also found in NSCLC specimens. In addition, upregulation of NRG1, VEGF and survivin was associated with poor overall survival in NSCLC patients. Moreover, enhanced production of NRG1 was detected in serum samples from NSCLC patients compared with healthy donors, and ROC analysis revealed the importance of NRG1 levels on distinguishing NSCLC samples and the controls. These findings suggested the novel diagnostic value of NRG1 in NSCLC. Additionally, upregulated protein levels of NRG1 and its target genes were also found in tissues samples of NSCLC patients compared with normal controls. These data indicated that NRG1 was a promising marker NSCLC, and it could be involved in tumor progression by targeting its downstream target including ErbB-Akt axis. Furthermore, the growth of lung cancer cells was suppressed by the knockdown of NRG1. Our findings could provide guidance for more accurate diagnosis for NSCLC, and future therapeutic approaches might be developed by better understanding of NRG-1-modulated molecular mechanisms during the tumor development in NSCLC.

Silencing LINC00482 inhibits tumor-associated inflammation and angiogenesis through down-regulation of MMP-15 via FOXA1 in bladder cancer.

Multiple studies have previously demonstrated that long intergenic non-coding RNAs (lincRNAs) play an important role in the development of bladder cancer. However, little is known regarding the underlying molecular mechanisms of LINC00482 functions in bladder cancer. The current study aimed to elucidate the role of LINC00482 in the progression of bladder cancer. The initial step was to detect the expressions of LINC00482 and MMP15 in bladder cancer cells and tissue. According to the results from the RT-qPCR, LINC00482 and MMP15 were both highly expressed in bladder cancer cells and tissue. The relationship among LINC00482, FOXA1 and MMP15 was studied via dual-luciferase reporter assay. LINC00482 was positively correlated with MMP15. LINC00482 promoted MMP15 expression by recruiting FOXA1. Using the gain- and loss-of-function approaches, silencing of LINC00482 resulted in the downregulation of VEGF and NF-κB protein levels, decreased expression of inflammatory factors, and inhibited angiogenesis. Silencing of LINC00482 also suppressed tumor-associated inflammation and angiogenesis in vivo, which was found to be reversed by the overexpression of MMP15. The present study demonstrated that LINC00482 induced the expression of MMP15 by interacting with FOXA1, thereby contributing to the inflammation and angiogenesis in bladder cancer.

Tumor-associated macrophage, angiogenesis and lymphangiogenesis markers predict prognosis of non-small cell lung cancer patients

BackgroundThe tumor microenvironment (TME) is a critical player in tumor progression, metastasis and therapy outcomes. Tumor-associated macrophages (TAMs) are a well-recognized core element of the TME and generally characterized as M2-like macrophages. TAMs are believed to contribute to tumor progression, but the mechanism behind this remains unclear. We aimed to investigate the clinical, angiogenic, and lymphangiogenic significance of TAMs in non-small cell lung cancer (NSCLC).MethodsUtilizing combined immunohistochemistry and digital image analysis, we assessed CD68, CD163, VEGF-A, and VEGF-C expression in 349 patients with NSCLC. Subsequently, the potential association between M2 TAMs and angiogenic VEGF-A and/or lymphangiogenic VEGF-C was evaluated for its prognostic value. Furthermore, the effects of M2 TAMs on angiogenesis and lymphangiogenesis were explored via an in vitro co-culture system.ResultsCD68 and CD163 expression were found to directly correlate with VEGF-A and/or VEGF-C expression (all p < 0.001). Furthermore, elevated M2 ratio (CD163+/CD68+) was significantly associated with poor overall survival (p = 0.023). Dual expression of M2 ratiohigh and VEGF-Chigh (M2 ratiohighVEGF-Chigh) was correlated with worse overall survival (p = 0.033). Multivariate analysis revealed that M2 ratiohigh [HR (95% CI) = 1.53 (1.01–2.33), p = 0.046] and combined M2 ratiohighVEGF-Chigh expression [HR (95% CI) = 2.01 (1.28–3.16), p = 0.003] were independent predictors of poor overall survival. Notably, we confirmed that M2 macrophages significantly enhanced the protein and mRNA expression of both VEGF-A and VEGF-C, while M1 macrophages induced only mRNA expression of VEGF-A in A549 cells.ConclusionsThis study suggests that TAMs are significantly associated with angiogenesis and lymphangiogenesis, contributing to the progression of NSCLC. Furthermore, elevated M2 ratio, similar to combined high M2 ratio and high VEGF-C expression, is a strong indicator of poor prognosis in patients with NSCLC, providing insight for future TAM-based immunotherapy strategies.

Elucidating the Association Between the Upregulation of Angiotensin Type 1-Receptors and the Development of Gastrointestinal Malignancies

The renin-angiotensin system (RAS) is a major regulator of body fluid hemostasis and blood pressure. Angiotensin type 1 receptors (AT1R) are one of the major components of this system and are widely expressed in different organs, including the gastrointestinal (GI) system. Very little known about the physiological roles of AT1R in GI tract but evidence has reported that local AT1Rs are upregulated in pathological conditions like GI malignancies and play role in stimulation of signaling pathways associated with GI cancers progression. AT1Rs axes signaling in tumor microenvironments stimulate inflammation and facilitate vascularization around the tumor cell to display invasive behavior. AT1Rs in stroma cells promote tumor-associated angiogenesis by upregulated of vessel endothelial growth factor (VEGF). Also, AT1Rs by the activation of molecular mechanisms such as PI3/Akt/NF-κB pathways increase the invasion of tumor cells. Experimental and clinical studies have reported that AT1R antagonists have beneficial influences by increasing the survival of patients with GI malignancies and reduction in the proliferation of GI cancer cell lines in vitro, and the growth and metastasis of tumors in vivo, therefore, AT1Rs antagonist have the potential for future anticancer strategies. This review focuses on the pathological roles of AT1Rs in GI malignancies.

Abstract 3970: Tumor-associated macrophage, angiogenesis and lymphangiogenesis predicts prognosis in patients with non-small cell lung cancer

Abstract Background: The tumor microenvironment (TME) is a critical player in tumor progression, metastasis and therapy outcome. Tumor-associated macrophages (TAMs) are a well-recognized core element of the TME, and are generally characterized as M2-like macrophages. TAMs are believed to contribute to tumor progression, but the mechanism behind this remains unclear. We aimed to investigate the clinical value, angiogenic and lymphangiogenic significance of TAMs in non-small cell lung cancer (NSCLC). Methods: We assessed CD68, CD163, VEGF-A, and VEGF-C expression in 349 patients with NSCLC by combined immunohistochemistry and digital image analysis. Subsequently, the potential association between M2 TAMs and angiogenetic VEGF-A and/or lymphangiogenetic VEGF-C was evaluated for its prognostic value. Furthermore, the effects of M2 TAMs on angiogenesis and lymphangiogenesis were explored in vitro co-culture system. Results: Elevated M2 (CD163+/CD68+) ratio was significantly associated with poor overall survival (p=0.023). Dual high expression of M2 ratio and VEGF-C was correlated with worse overall survival (p=0.033). Furthermore, CD68 and CD163 expression are positively associated with VEGF-A and/or VEGF-C expression. Multivariate analysis revealed that M2 ratio was an independent predictor of poor survival [HR (95% CI) = 1.53 (1.01-2.33), p=0.046]. Combined M2+/VEGF-C+ expression was also an independent predictor of poor survival [HR (95% CI) = 2.01 (1.28-3.16), p=0.003]. Notably, we confirmed that M2 macrophages enhanced the protein and mRNA expression of both VEGF-A and VEGF-C significantly, while M1 macrophages induced only mRNA expression of VEGF-A significantly in A549 cells. Conclusions: This study suggests that TAMs are significantly associated with angiogenesis or lymphangiogenesis in the progression of NSCLC. Furthermore, elevated M2 ratio and combined M2 and VEGF-C high expression are strong indicators of poor prognosis in patients with NSCLC. Citation Format: Ilseon Hwang, Keun Uk Park, Eun Hee Jung, Hun-Mo Ryoo, Kris Ylaya, Joon-Yong Chung, Stephen M. Hewitt. Tumor-associated macrophage, angiogenesis and lymphangiogenesis predicts prognosis in patients with non-small cell lung cancer [abstract]. In: Proceedings of the Annual Meeting of the American Association for Cancer Research 2020; 2020 Apr 27-28 and Jun 22-24. Philadelphia (PA): AACR; Cancer Res 2020;80(16 Suppl):Abstract nr 3970.

Characterization of Tumor Blood Vasculature Expression of Human Invasive Bladder Cancer by Laser Capture Microdissection and Transcriptional Profiling

Tumor-associated blood vessels differ from normal vessels and play key roles in tumor progression. We aimed to identify biomolecules that are expressed differentially in human bladder cancer-associated blood vessels to find novel biomarkers and mechanisms involved in tumor-associated angiogenesis. The transcriptome of tumor blood vasculature from human invasive bladder carcinoma (I-BLCA) and normal bladder tissue vasculature was compared using differential expression and unsupervised hierarchical clustering analyses. Pathway analysis identified up-regulation of genes involved in the proliferation, cell cycle, angiogenesis, inflammation, and transforming growth factor-β signaling in tumor blood vasculature. A common consensus gene expression signature was identified between bladder cancer tumor blood vasculature with tumor blood vasculature of other solid cancers, which correlated with the overall survival of patients with several of the solid cancers investigated in The Cancer Genome Atlas data set. In bladder tumor blood vasculature, the secreted factor angiopoietin-like protein 2 (ANGPTL2), was confirmed to be up-regulated by quantitative RT-PCR and immunohistochemical staining. The up-regulation of ANGPTL2 in plasma was also observed in non-invasive bladder carcinoma and I-BLCA. We semiquantitatively analyzed expression of ANGPTL2 in tissue microarrays from I-BLCA and surprisingly found an opposite correlation between staining intensity and progression-free survival. Our results indicate that ANGPTL2 might serve as a potential biomarker to predict progression-free survival in I-BLCA.

Pro-Angiogenic and Pro-Inflammatory Regulation by lncRNA MCM3AP-AS1-Mediated Upregulation of DPP4 in Clear Cell Renal Cell Carcinoma.

Clear cell renal cell carcinoma (ccRCC) represents the most common type of renal cell carcinoma (RCC) in adults, in addition to the worst prognosis among the common epithelial kidney tumors. Inflammation and angiogenesis seem to potentiate tumor growth and metastasis of the malignancy. The current study explored the contributions of the lncRNA MCM3AP-AS1 in tumor-associated inflammation and angiogenesis in ccRCC with a specific focus on its transcriptional regulation and its interactions with transcription factor E2F1 and DPP4. Tumor tissues and matched adjacent non-tumor tissues were collected from 78 ccRCC patients. Methylation-specific PCR and ChIP assays were applied to detect the methylation at the promoter region of MCM3AP-AS1. Dual-luciferase reporter assay, RIP, RNA pull-down, and ChIP assays were employed to confirm the interactions between MCM3AP-AS1, E2F1, and DPP4. Nude mice were subcutaneously xenografted with human ccRCC cells. Cell proliferation was evaluated by CCK-8 assays and EDU staining in ccRCC cells in vitro and by immunohistochemical staining of Ki67 in vivo. Inflammation was examined by detecting the secretion of pro-inflammatory cytokines (TNF-α, IL-1β, and IL-6). Pro-angiogenic ability of ccRCC cells was assessed by the co-culture with human umbilical vein endothelial cells (HUVEC) in vitro and by microvessel density (MVD) measurements and angiogenesis in the chicken chorioallantoic membrane. MCM3AP-AS1 was highly-expressed in ccRCC and associated with poor patient survival. Demethylation of MCM3AP-AS1 was noted in ccRCC tissues and cells. Over-expression of MCM3AP-AS1 enhanced cell proliferation, the release of pro-inflammatory cytokines, and the tube formation of HUVECs in cultured human Caki-1 and 786-O cells. MCM3AP-AS1 was shown to enhance the E2F1 enrichment at the DPP4 promoter, to further increase the expression of DPP4. Knockdown of DPP4 could abate pro-angiogenic and pro-inflammatory abilities of MCM3AP-AS1 in ccRCC cells. Pro-angiogenic and pro-inflammatory abilities of MCM3AP-AS1 in vivo were confirmed in mice subcutaneously xenografted with human ccRCC cells. Our findings demonstrate a novel mechanism by which lncRNA MCM3AP-AS1 exerts pro-angiogenic and pro-inflammatory effects, highlighting the potential of MCM3AP-AS1 as a promising target for treating ccRCC.

Angiopoietin-1 is associated with a decreased risk of lymph node metastasis in early stage cervical cancer.

Lymph node metastasis (LNM) is an important determinant of prognosis in patients with cervical cancer. Members of the angiopoietin family have been demonstrated to regulate tumor-associated angiogenesis and lymphangiogenesis. This study aimed to investigate the expression levels of angiopoietin-1 (ANG1) and angiopoietin-2 (ANG2) in clinically early stage of cervical cancer along with their correlations with LNM. In total, 124 human cervical cancer cases classified into stage IA-IIB in accordance with the International Federation of Gynecology and Obstetrics (FIGO) 2009 staging criteria were included. ANG1 and ANG2 expression levels in the tumor sections were assessed by immunohistochemistry (IHC). Univariate and multivariate logistic regression models, including age at diagnosis, FIGO stage, tumor size, pathological type, histological grading, depth of stromal invasion, lymph-vascular space invasion (LVSI) and the expression status of ANG1 and ANG2, were used to evaluate the odds ratios (ORs) for LNM. ANG1 and ANG2 were positively expressed in 75 (60.5%) and 89 (71.8%) cervical cancers respectively, with predominant staining in the cytoplasm. ANG1 expression was significantly decreased in tumors with LNM, while no correlation was observed between ANG2 expression and LNM. More importantly, the multivariate logistic regression analysis demonstrated that high ANG1 expression was an independent protective factor of LNM (OR 0.107, 95% confidential interval [CI] 0.020~0.567), while LVSI was an independent risk factor of LNM (OR 34.313, 95% CI 5.914~199.092). ANG1 is associated with a significantly decreased risk of LNM in early stage cervical cancer. The predictive value and role of ANG1 in LNM needs to be further investigated in future studies.

MiR-151a enhances Slug dependent angiogenesis.

MicroRNAs (miRs) are small non-coding RNAs, that modulate cognate gene expression either by inducing mRNA degradation or by blocking translation, and play crucial and complex roles in tissue homeostasis and during disease initiation and progression. The sprouting of new blood vessels by angiogenesis is critical in vascular development and homeostasis and aberrant angiogenesis is associated with pathological conditions such as ischemia and cancer. We have previously established that miR-151a functions as an onco-miR in non-small cell lung cancer (NSCLC) cells by inducing partial EMT and enhancing tumor growth. Here, we identify anti-miR-151a as a molecule that promotes endothelial cell contacts and barrier properties, suggesting that miR-151a regulates cell-cell junctions. We find that induced miR-151a expression enhances endothelial cell motility and angiogenesis and these functions depend on miR-151a-induced Slug levels. Moreover, we show that miR-151a overexpression enhances tumor-associated angiogenesis in 3D vascularized tumor spheroid assays. Finally, we verify that miR-151a is expressed in the vasculature of normal lung and NSCLC tissue. Our results suggest that miR-151a plays multi-faceted roles in the lung, by regulating multiple functions (cell growth, motility, partial EMT and angiogenesis) in distinct cell types.

Targeting the vascular endothelial growth factor receptor-1 by the monoclonal antibody D16F7 to increase the activity of immune checkpoint inhibitors against cutaneous melanoma

The vascular endothelial growth factor receptor-1 (VEGFR-1) is a membrane receptor for VEGF-A, placenta growth factor (PlGF) and VEGF-B that plays a crucial role in melanoma invasiveness, vasculogenic mimicry and tumor-associated angiogenesis. Furthermore, activation of VEGFR-1 is involved in the mobilization of myeloid progenitors from the bone marrow that infiltrate the tumor. Myeloid-derived suppressor cells and tumor-associated macrophages have been involved in tumor progression and resistance to cancer treatment with immune checkpoint inhibitors (ICIs). We have recently demonstrated that the anti-VEGFR-1 monoclonal antibody (mAb) D16F7 developed in our laboratories is able to inhibit melanoma growth in preclinical in vivo models and to reduce monocyte/macrophage progenitor mobilization and tumor infiltration by myeloid cells. Aim of the study was to investigate whether the anti-VEGFR-1 mAb D16F7 affects the activity of protumoral M2 macrophages in vitro in response to PlGF and inhibits the recruitment of these cells to the melanoma site in vivo. Finally, we tested whether, through its multi-targeted action, D16F7 mAb might increase the efficacy of ICIs against melanoma. The results indicated that VEGFR-1 expression is up-regulated in human activated M2 macrophages compared to activated M1 cells and exposure to the D16F7 mAb decreases in vitro chemotaxis of activated M2 macrophages. In vivo treatment with the anti-VEGFR-1 mAb D16F7 of B6D2F1 mice injected with syngeneic B16F10 melanoma cells resulted in tumor growth inhibition associated with the modification of tumor microenvironment that involves a decrease of melanoma infiltration by M2 macrophages and PD-1+ and FoxP3+ cells. These alterations result in increased M1/M2 and CD8+/FoxP3+ ratios, which favor an antitumor and immunostimulating milieu. Accordingly, D16F7 mAb increased the antitumor activity of the ICIs anti-CTLA-4 and anti-PD-1 mAbs. Overall, these data reinforce the role of VEGFR-1-mediated-signalling as a valid target for reducing tumor infiltration by protumoral macrophages and for improving the efficacy of immunotherapy with ICIs.