Tumor angiogenesis and lymphangiogenesis: tumor/endothelial crosstalk and cellular/microenvironmental signaling mechanisms

Tumor lymphangiogenesis index reveals the immune landscape and immunotherapy response in lung adenocarcinoma

Background

Lymphangiogenesis (LYM) has an important role in tumor progression and is strongly associated with tumor metastasis. However, the clinical application of LYM has not progressed as expected. The potential value of LYM needs to be further developed in lung adenocarcinoma (LUAD) patients.

Methods

The Sequencing data and clinical characteristics of LUAD patients were downloaded from The Cancer Genome Atlas and GEO databases. Multiple machine learning algorithms were used to screen feature genes and develop the LYM index. Immune cell infiltration, immune checkpoint expression, Tumor Immune Dysfunction and Exclusion (TIDE) algorithm and drug sensitivity analysis were used to explore the correlation of LYM index with immune profile and anti-tumor therapy.

Results

We screened four lymphangiogenic feature genes (PECAM1, TIMP1, CXCL5 and PDGFB) to construct LYM index based on multiple machine learning algorithms. We divided LUAD patients into the high LYM index group and the low LYM index group based on the median LYM index. LYM index is a risk factor for the prognosis of LUAD patients. In addition, there was a significant difference in immune profile between high LYM index and low LYM index groups. LUAD patients in the low LYM index group seemed to benefit more from immunotherapy based on the results of TIDE algorithm.

Conclusion

Overall, we confirmed that the LYM index is a prognostic risk factor and a valuable predictor of immunotherapy response in LUAD patients, which provides new evidence for the potential application of LYM.

Expression of an oxysterol-metabolizing enzyme in colorectal cancer and its relation to tumor cell behavior and prognosis

Oxysterols and oxysterol-metabolizing enzymes have been implicated in the pathogenesis of various cancers. However, the distinct function of the oxysterol-metabolizing enzyme cytochrome P450 family 39 Subfamily A Member 1 (CYP39A1) in colorectal cancer (CRC) remains unclear. The aims of the current study were to evaluate whether CYP39A1 affects the oncogenic behaviors of CRC cells and to investigate the prognostic value of its expression in CRC. A CYP39A1 small-interfering RNA was used to block CYP39A1 gene expression in DLD1 and SW480 cells. The expression of CYP39A1 in CRC tissues was investigated by immunohistochemistry. Tumor angiogenesis and lymphangiogenesis were assessed by CD34 and D2-40 immunohistochemical staining, respectively. CYP39A1 knockdown inhibited tumor cell migration and invasion in DLD1 and SW480 cells. Angiogenesis was also inhibited through the decreased expression of vascular endothelial growth factor (VEGF)-A and hypoxia-inducible factor (HIF)-1α, and angiostatin and endostatin expression increased. In addition, CYP39A1 knockdown inhibited the lymphangiogenesis by decreasing the expression of VEGF-C. CYP39A1 expression was increased in CRC tissues compared with normal colorectal mucosa. CYP39A1 expression was associated with tumor stage, depth of invasion, lymph node metastasis, distant metastasis, and poor survival. The microvessel and lymphatic vessel density values of CYP39A1-positive tumors were significantly higher than those of CYP39A1-negative tumors. These results indicate that CYP39A1 is associated with tumor progression by influencing tumor cell angiogenesis and lymphangiogenesis in CRC.

Polarization of Cancer-Associated Macrophages Maneuver Neoplastic Attributes of Pancreatic Ductal Adenocarcinoma

Mounting evidence links the phenomenon of enhanced recruitment of tumor-associated macrophages towards cancer bulks to neoplastic growth, invasion, metastasis, immune escape, matrix remodeling, and therapeutic resistance. In the context of cancer progression, naïve macrophages are polarized into M1 or M2 subtypes according to their differentiation status, gene signatures, and functional roles. While the former render proinflammatory and anticancer effects, the latter subpopulation elicits an opposite impact on pancreatic ductal adenocarcinoma. M2 macrophages have gained increasing attention as they are largely responsible for molding an immune-suppressive landscape. Through positive feedback circuits involving a paracrine manner, M2 macrophages can be amplified by and synergized with neighboring neoplastic cells, fibroblasts, endothelial cells, and non-cell autonomous constituents in the microenvironmental niche to promote an advanced disease state. This review delineates the molecular cues expanding M2 populations that subsequently convey notorious clinical outcomes. Future therapeutic regimens shall comprise protocols attempting to abolish environmental niches favoring M2 polarization; weaken cancer growth typically assisted by M2; promote the recruitment of tumoricidal CD8⁺ T lymphocytes and dendritic cells; and boost susceptibility towards gemcitabine as well as other chemotherapeutic agents.

Neo-vascularization-based therapeutic perspectives in advanced ovarian cancer

The process of angiogenesis is well described for its potential role in the development of normal ovaries, and physiological functions as well as in the initiation, progression, and metastasis of ovarian cancer (OC). In advanced stages of OC, cancer cells spread outside the ovary to the pelvic, abdomen, lung, or multiple secondary sites. This seriously limits the efficacy of therapeutic options contributing to fatal clinical outcomes. Notably, a variety of angiogenic effectors are produced by the tumor cells to initiate angiogenic processes leading to the development of new blood vessels, which provide essential resources for tumor survival, dissemination, and dormant micro-metastasis of tumor cells. Multiple proangiogenic effectors and their signaling axis have been discovered and functionally characterized for potential clinical utility in OC. In this review, we have provided the current updates on classical and emerging proangiogenic effectors, their signaling axis, and the immune microenvironment contributing to the pathogenesis of OC. Moreover, we have comprehensively reviewed and discussed the significance of the preclinical strategies, drug repurposing, and clinical trials targeting the angiogenic processes that hold promising perspectives for the better management of patients with OC.

Functional roles of SRC signaling in pancreatic cancer: Recent insights provide novel therapeutic opportunities

Pancreatic ductal adenocarcinoma (PDAC) is an aggressive malignant disease with a 5-year survival rate of <10%. Aberrant activation or elevated expression of the tyrosine kinase c-SRC (SRC) is frequently observed in PDAC and is associated with a poor prognosis. Preclinical studies have revealed a multifaceted role for SRC activation in PDAC, including promoting chronic inflammation, tumor cell proliferation and survival, cancer cell stemness, desmoplasia, hypoxia, angiogenesis, invasion, metastasis, and drug resistance. Strategies to inhibit SRC signaling include suppressing its catalytic activity, inhibiting protein stability, or by interfering with signaling components of the SRC signaling pathway including suppressing protein interactions of SRC. In this review, we discuss the molecular and immunological mechanisms by which aberrant SRC activity promotes PDAC tumorigenesis. We also provide a comprehensive update of SRC inhibitors in the clinic, and discuss the clinical challenges associated with targeting SRC in pancreatic cancer.

Colorectal cancer inhibitory properties of polysaccharides and their molecular mechanisms: A review

Colorectal cancer (CRC) is one of the three major malignant tumors in the world. The major treatments currently recommended for it are surgery, radiotherapy, and chemotherapy, all of which are frequently accompanied by a poor prognosis and high recurrence rate. To limit cell proliferation and metastasis, trigger cell apoptosis, and regulate tumor microenvironment (TME), researchers are focusing attention on investigating highly effective and non-toxic natural medicines. According to the research reported in 89 pieces of related literature, between 2018 and 2021, specialists extracted 48 different types of polysaccharides with CRC inhibitory actions from various plants, including Dendrobium officinale Kimura et Migo., Nostoc commune Vaucher, and Ganoderma lucidum (Leyss. ex Fr.) Karst. The novel founded mechanisms mainly include: inhibiting cancer cell proliferation by acting on IRS1/PI3K/Akt and IL-6/STAT3 pathways; inducing cancer cell apoptosis by acting on LncRNA HOTAIR/Akt mediated-intrinsic apoptosis, or regulating the TNF-α-mediated extrinsic apoptosis; inducing cancer cell autophagy by acting on endoplasmic reticulum stress or mTOR-TFEB pathway; inhibiting cancer cell metastasis by regulating Smad2/3 and TLR4/JNK pathways; regulating TME in CRC; and maintaining the intestinal barrier. This review will provide more novel research strategies and a solid literature basis for the application of polysaccharides in the treatment of CRC.

VEGFR3 suppression through miR-1236 inhibits proliferation and induces apoptosis in ovarian cancer via ERK1/2 and AKT signaling pathways

Vascular endothelial growth factor receptor 3 (VEGFR3) is expressed in cancer cell lines and exerts a critical role in cancer progression. However, the signaling pathways of VEGFR3 in ovarian cancer cell proliferation remain unclear. This study aimed to demonstrate the signaling pathways of VEGFR3 through the upregulated expression of miR-1236 in ovarian cancer cells. We found that the messenger RNA and protein of VEGFR3 were expressed in the ovarian cancer cell lines, but downregulated after microRNA-1236 (miR-1236) transfection. The inhibition of VEGFR3, using miR-1236, significantly reduced cell proliferation, clonogenic survival, migration, and invasion ability in SKOV3 and OVCAR3 cells (p < 0.01). The flow cytometry results indicated that the rate of apoptotic cells in SKOV3 (38.65%) and OVCAR3 (41.95%) cells increased following VEGFR3 inhibition. Moreover, VEGFR3 stimulation (using a specific ligand, VEGF-CS) significantly increased extracellular signal-regulated kinase 1/2 (ERK1/2) and protein kinase B (AKT) phosphorylation (p < 0.01), whereas VEGFR3 suppression reduced p-ERK1/2 (67.94% in SKOV3 and 93.52% in OVCAR3) and p-AKT (59.56% in SKOV3 and 78.73% in OVCAR3) compared to the VEGF-CS treated group. This finding demonstrated that miR-1236 may act as an endogenous regulator of ERK1/2 and AKT signaling by blocking the upstream regulator of VEGFR3. Overall, we demonstrated the important role of the miR-1236/VEGFR3 axis in ovarian cancer cell proliferation by regulating the ERK1/2 and AKT signaling that might be an effective strategy against ovarian cancer.

Blood Vessel Organoids for Development and Disease

Despite enormous advances, cardiovascular disorders are still a major threat to global health and are responsible for one-third of deaths worldwide. Research for new therapeutics and the investigation of their effects on vascular parameters is often limited by species-specific pathways and a lack of high-throughput methods. The complex 3-dimensional environment of blood vessels, intricate cellular crosstalks, and organ-specific architectures further complicate the quest for a faithful human in vitro model. The development of novel organoid models of various tissues such as brain, gut, and kidney signified a leap for the field of personalized medicine and disease research. By utilizing either embryonic- or patient-derived stem cells, different developmental and pathological mechanisms can be modeled and investigated in a controlled in vitro environment. We have recently developed self-organizing human capillary blood vessel organoids that recapitulate key processes of vasculogenesis, angiogenesis, and diabetic vasculopathy. Since then, this organoid system has been utilized as a model for other disease processes, refined, and adapted for organ specificity. In this review, we will discuss novel and alternative approaches to blood vessel engineering and explore the cellular identity of engineered blood vessels in comparison to in vivo vasculature. Future perspectives and the therapeutic potential of blood vessel organoids will be discussed.

The Emerging Role of Exosomal miRNAs as Biomarkers for Early Cancer Detection: A Comprehensive Literature Review

A significant number of cancer-related deaths are recorded globally each year, despite attempts to cure this illness. Medical science is working to develop new medication therapies as well as to find ways to identify this illness as early as possible, even using noninvasive techniques. Early detection of cancer can greatly aid its treatment. Studies into cancer diagnosis and therapy have recently shifted their focus to exosome (EXO) biomarkers, which comprise numerous RNA and proteins. EXOs are minuscule goblet vesicles that have a width of 30 to 140 nm and are released by a variety of cells, including immune, stem, and tumor cells, as well as bodily fluids. According to a growing body of research, EXOs, and cancer appear to be related. EXOs from tumors play a role in the genetic information transfer between tumor and basal cells, which controls angiogenesis and fosters tumor development and spread. To identify malignant activities early on, microRNAs (miRNAs) from cancers can be extracted from circulatory system EXOs. Specific markers can be used to identify cancer-derived EXOs containing miRNAs, which may be more reliable and precise for early detection. Conventional solid biopsy has become increasingly limited as precision and personalized medicine has advanced, while liquid biopsy offers a viable platform for noninvasive diagnosis and prognosis. Therefore, the use of body fluids such as serum, plasma, urine, and salivary secretions can help find cancer biomarkers using technologies related to EXOs.

Macrophages as a Potential Immunotherapeutic Target in Solid Cancers

The revolution in cancer immunotherapy over the last few decades has resulted in a paradigm shift in the clinical care of cancer. Most of the cancer immunotherapeutic regimens approved so far have relied on modulating the adaptive immune system. In recent years, strategies and approaches targeting the components of innate immunity have become widely recognized for their efficacy in targeting solid cancers. Macrophages are effector cells of the innate immune system, which can play a crucial role in the generation of anti-tumor immunity through their ability to phagocytose cancer cells and present tumor antigens to the cells of adaptive immunity. However, the macrophages that are recruited to the tumor microenvironment predominantly play pro-tumorigenic roles. Several strategies targeting pro-tumorigenic functions and harnessing the anti-tumorigenic properties of macrophages have shown promising results in preclinical studies, and a few of them have also advanced to clinical trials. In this review, we present a comprehensive overview of the pathobiology of TAMs and their role in the progression of solid malignancies. We discuss various mechanisms through which TAMs promote tumor progression, such as inflammation, genomic instability, tumor growth, cancer stem cell formation, angiogenesis, EMT and metastasis, tissue remodeling, and immunosuppression, etc. In addition, we also discuss potential therapeutic strategies for targeting TAMs and explore how macrophages can be used as a tool for next-generation immunotherapy for the treatment of solid malignancies.

Acquired lymphedema: Molecular contributors and future directions for developing intervention strategies

Lymphedema is a debilitating chronic disease that mostly develops as an adverse reaction to cancer treatment modalities such as chemotherapy, surgery, and radiotherapy. Lymphedema also appears to be a deteriorating consequence of roundworm infections, as best represented by filariasis. According to its origin, lymphedema is classified as primary lymphedema and acquired lymphedema. The latter is an acquired condition that, hitherto, received a considerably low attention owing to the less number of fatal cases been reported. Notably, despite the low mortality rate in lymphedema, it has been widely reported to reduce the disease-free survival and thus the quality of life of affected patients. Hence, in this review, we focused on acquired lymphedema and orchestration of molecular interplays associated with either stimulation or inhibition of lymphedema development that were, in vast majority, clearly depicted in animal models with their specific and distinct technical approaches. We also discussed some recent progress made in phytochemical-based anti-lymphedema intervention strategies and the specific mechanisms underlying their anti-lymphedema properties. This review is crucial to understand not only the comprehensive aspects of the disease but also the future directions of the intervention strategies that can address the quality of life of affected patients rather than alleviating apparent symptoms only.

Chronic inflammation, cancer development and immunotherapy

Chronic inflammation plays a pivotal role in cancer development. Cancer cells interact with adjacent cellular components (pro-inflammatory cells, intrinsic immune cells, stromal cells, etc.) and non-cellular components to form the inflammatory tumor microenvironment (TME). Interleukin 6 (IL-6), macrophage migration inhibitory factor (MIF), immune checkpoint factors and other pro-inflammatory cytokines produced by intrinsic immune cells in TME are the main mediators of intercellular communication in TME, which link chronic inflammation to cancer by stimulating different oncogenic signaling pathways and improving immune escape to promote cancer development. In parallel, the ability of monocytes, T regulatory cells (Tregs) and B regulatory cells (Bregs) to perform homeostatic tolerogenic functions is hijacked by cancer cells, leading to local or systemic immunosuppression. Standard treatments for advanced malignancies such as chemotherapy and radiotherapy have improved in the last decades. However, clinical outcomes of certain malignant cancers are not satisfactory due to drug resistance and side effects. The clinical application of immune checkpoint therapy (ICT) has brought hope to cancer treatment, although therapeutic efficacy are still limited due to the immunosuppressive microenvironment. Emerging evidences reveal that ideal therapies including clearance of tumor cells, disruption of tumor-induced immunosuppression by targeting suppressive TME as well as reactivation of anti-tumor T cells by ICT. Here, we review the impacts of the major pro-inflammatory cells, mediators and their downstream signaling molecules in TME on cancer development. We also discuss the application of targeting important components in the TME in the clinical management of cancer.

Fibroblasts mediate the angiogenesis of pheochromocytoma by increasing COX4I2 expression

Objective

Our previous work found COX4I2 was associated with angiogenesis in pheochromocytoma. The purpose of this study was to explore the role of COX4I2 in regulating angiogenesis in pheochromocytoma.

Methods

Distribution of COX4I2 was evaluated by scRNA-seq in one case of pheochromocytoma and the findings were verified by immunostaining. COX4I2 was further knocked down in target cells. Changes of angiogenesis-related genes were evaluated by qPCR in target cells.

Results

The scRNA-seq revealed high mRNA expression of COX4I2 in fibroblasts rather than tumor cells. Immunostaining of COX4I2 confirmed its distribution in fibroblasts. Knocking down COX4I2 in NIH3T3 cell line led to significant reduction of angiogenesis-related genes, especially ANG1 and HGF.

Conclusions

Fibroblasts mediate the angiogenesis of pheochromocytoma by increasing COX4I2 expression, possibly by affecting ANG1 and HGF.

Methyl Gallate Suppresses Tumor Development by Increasing Activation of Caspase3 and Disrupting Tumor Angiogenesis in Melanoma

Methyl gallate is a phenolic compound mainly found in medicinal plants. It has been reported to its anticancer activity in various tumors. In this study, we aimed to demonstrate the antitumor effect of methyl gallate in the melanoma mouse model and B16F10 cells. Our results showed that methyl gallate decreased cell viability and induced apoptosis by increasing the expression of cleaved caspase3 in B16F10 cells and prevented cell migration and tube formation in human umbilical vein endothelial cells. In B16F10 cell-inoculated mice, methyl gallate not only decreased tumor volume by 30% but also significantly reduced tumor vessel density and pericyte coverage. Moreover, methyl gallate diminished by close to 50% the expression of cytokeratin and LYVE-1 in mouse right inguinal lymph nodes, indicating that methyl gallate could suppress metastasis. In conclusion, this study suggests that methyl gallate inhibits tumor development by inducing apoptosis and blocking tumor angiogenesis and metastasis and might be considered a therapeutic agent for melanoma.

HMGB1 Promotes Lymphangiogenesis through the Activation of RAGE on M2 Macrophages in Laryngeal Squamous Cell Carcinoma

Background. Receptor for advanced glycation end products (RAGE) is implicated in tumor biology. Released high mobility group box protein 1 (HMGB1) ligand binding to RAGE receptor in tumor cells promotes tumor progression. The mechanisms of HMGB1-RAGE signaling in M2 macrophages involved in lymphangiogenesis in laryngeal carcinoma remain poorly understood. Here, we assessed the effect of HMGB1-RAGE signaling on M2 macrophages in lymphangiogenesis. Methods. HMGB1, CD163, and D2-40 in laryngeal squamous cell carcinoma (LSCC, $n=123$ ), laryngeal precursor lesions (LPLs, $n=102$ ), and vocal polyp (VP, $n=55$ ) were analyzed by immunohistochemistry. THP-1 cell-expressed RAGE gene was knocked down and then polarized to M0 macrophages and M2 macrophages. IL-23, TNF-α, TGF-β, and IL-10 were measured by ELISA; IL-1β, IL-12, IL-10, and CCL-13 were evaluated by RT-qPCR, and CD206, CD163, and RAGE were evaluated by western blot to evaluate whether classical M2 macrophages were obtained. Conditioned media from RAGE+/- M0 macrophages and RAGE+/- M2 macrophages incubated in the presence or absence of HMGB1, anti-Toll-like receptor (TLR)2, anti-TLR4 antibodies, and anti-VEGF-C antibodies were collected separately for human dermal lymphatic endothelial cells (HDLEC) for proliferation, migration, lymphangiogenesis assay, and VEGF-C concentration analysis. Results. HMGB1 and M2 macrophage densities were increased in LSCC ( $P<0.01$ ). HMGB1 and M2 macrophage densities were significantly correlated with lymphatic vessel density (LVD) in LSCC ( $P<0.01$ ). The HMGB1 overexpression and higher M2 macrophage density were involved in lymph node metastasis ( $P<0.01$ ) and poor prognosis ( $P<0.05$ ). In vitro, conditioned medium from HMGB1-stimulated RAGE+ M2 macrophages activated lymphangiogenesis by upregulating the VEGF compared to controls ( $P<0.05$ ). On the contrary, RAGE knockdown obviously decreased the corresponding effects of HMGB1-preconditioned M2 macrophages upon HDLEC ( $P<0.05$ ). HMGB1-TLR pathway does not significantly increase HDLEC proliferation, migration, and lymphangiogenesis on M2 macrophages. Conclusions. HMGB1 promotes lymphangiogenesis by activation of RAGE on M2 macrophages. Targeting RAGE may provide an effective therapeutic strategy against M2 macrophages in LSCC patients with lymph node metastasis.

Tumor microenvironment remodeling modulates macrophage phenotype in breast cancer lymphangiogenesis

Hyaluronan (HA) is dynamically remodeled in tumor microenvironment (TME) and is reported to be closely related to tumor lymphatic metastasis by inducing lymphangiogenesis. Macrophages are known to be involved in neo-lymphatic vessels formation. However, few studies have investigated the role of HA-mediated TME remodeling on macrophages-dependent lymphangiogenesis. We previously showed that HA could drive macrophages to acquire the M2 phenotype. In this study, we attempt to study the crosstalk between HA in TME and macrophages dependent lymphangiogenesis. First, we found that the abundant assembly of HA in breast cancer tissue was accompanied by increased infiltration of macrophages featured by expressing lymphatic endothelial markers. Then, to further identify the remodeling of HA in regulating macrophage phenotype, we used HA fragments which are usually enriched in TME for this purpose. Our results showed that the reconstructed HA could induce bone marrow-derived macrophages (BMDMs) to express markers of lymphatic endothelium and form tube-like structures, suggesting a novel function of HA from TME on macrophages-dependent lymphangiogenesis. Finally, we found that inhibition of the HA-TLR4 pathway could reduce the ability of BMDMs to exhibit lymphatic endothelial phenotype. Our results provide new insight into tumor microenvironment remodeling and macrophages in breast cancer lymphangiogenesis.

Emerging Role of Autophagy in the Development and Progression of Oral Squamous Cell Carcinoma

Autophagy is a cellular catabolic process, which is characterized by degradation of damaged proteins and organelles needed to supply the cell with essential nutrients. At basal levels, autophagy is important to maintain cellular homeostasis and development. It is also a stress responsive process that allows the cells to survive when subjected to stressful conditions such as nutrient deprivation. Autophagy has been implicated in many pathologies including cancer. It is well established that autophagy plays a dual role in different cancer types. There is emerging role of autophagy in oral squamous cell carcinoma (OSCC) development and progression. This review will focus on the role played by autophagy in relation to different aspects of cancer progression and discuss recent studies exploring the role of autophagy in OSCC. It will further discuss potential therapeutic approaches to target autophagy in OSCC.

Antiangiogenic role of natural flavonoids and their molecular mechanism: an update

Background

Angiogenesis is the development of new blood vessels from the existing vasculature, which is important in normal developmental processes. Angiogenesis is a key step in tumor growth, invasion, and metastasis. Angiogenesis is necessary for the proper nourishment and removal of metabolic wastes from tumor sites. Therefore, modulation of angiogenesis is considered a therapeutic strategy of great importance for human health.

Main body

Numerous bioactive plant compounds are recently tested for their antiangiogenic potential. Among the most frequently studied are flavonoids which are abundantly present in fruits and vegetables. Flavonoids inhibit angiogenesis and metastasis through the regulation of multiple signaling pathways. Flavonoids regulate the expression of VEGF, matrix metalloproteinases (MMPs), EGFR, and inhibit NFB, PI3-K/Akt, and ERK1/2 signaling pathways, thereby causing strong antiangiogenic effects. This present review aimed to provide up-to-date information on the molecular mechanisms of antiangiogenic properties of natural flavonoids.

Conclusion

Presently developed antiangiogenic drugs in malignant growth treatment do not meet assumptions about adequacy and safety. So further investigations are needed in this field in the future. More recently, flavonoids are the most effective antiangiogenic agent, by inhibition of signaling pathways.

Inhibition of Hepatic Stellate Cell Activation Suppresses Tumorigenicity of Hepatocellular Carcinoma in Mice

Transdifferentiation (or activation) of hepatic stellate cells (HSCs) to myofibroblasts is a key event in liver fibrosis. Activated HSCs in the tumor microenvironment reportedly promote tumor progression. This study analyzed the effect of an inhibitor of HSC activation, retinol-binding protein–albumin domain III fusion protein (R-III), on protumorigenic functions of HSCs. Although conditioned medium collected from activated HSCs enhanced the migration, invasion, and proliferation of the hepatocellular carcinoma cell line Hepa-1c1c7, this effect was not observed in Hepa-1c1c7 cells treated with conditioned medium from R-III–exposed HSCs. In a subcutaneous tumor model, larger tumors with increased vascular density were formed in mice transplanted with Hepa-1c1c7+HSC than in mice transplanted with Hepa-1c1c7 cells alone. Intriguingly, when Hepa-1c1c7+HSC–transplanted mice were injected intravenously with R-III, a reduction in vascular density and extended tumor necrosis were observed. In an orthotopic tumor model, co-transplantation of HSCs enhanced tumor growth, angiogenesis, and regional metastasis accompanied by increased peritumoral lymphatic vessel density, which was abolished by R-III. In vitro study showed that R-III treatment affected the synthesis of pro-angiogenic and anti-angiogenic factors in activated HSCs, which might be the potential mechanism underlying the R-III effect. These findings suggest that the inhibition of HSC activation abrogates HSC-induced tumor angiogenesis and growth, which represents an attractive therapeutic strategy.

Identification of miR-203a, mir-10a, and miR-194 as predictors for risk of lymphovascular invasion in head and neck cancers

Lymphovascular invasion (LVI) is an important prognostic indicator of lymph node metastasis and disease aggressiveness but clear molecular mechanisms mediating this in head and neck cancers (HNSC) remain undefined. To identify important microRNAs (miRNAs) in HNSC that associate with and are also predictive of increased risk of LVI, we used a combination of clustering algorithms, multiple regression analyses and machine learning approaches and analyzed miRNA expression profiles in the TCGA HNSC database. As the first step, we identified miRNAs with increased association with LVI as a binary variable. In order to determine whether the identified miRNAs would show functional clusters that are also indicative of increased risk for LVI, we carried out unsupervised as well as supervised clustering. Our results identified distinct clusters of miRNAs that are predictive of increased LVI. We further refined these findings using a Random forest approach, and miR-203a-3p, mir-10a-5p, and miR-194-5p to be most strongly associated with LVI. Pathway enrichment analysis showed these miRNAs targeted genes involved in Hippo signaling and fatty acid oxidation pathways that are mediators of lymph node metastasis. Specific association was also identified between the miRNAs associated with LVI and expression of several lymphangiogenic genes that could be critical for determination of therapeutic strategies.

Tumor-Associated Macrophages in Pancreatic Ductal Adenocarcinoma: Therapeutic Opportunities and Clinical Challenges

Simple Summary

Macrophages are a major component of the pancreatic tumor microenvironment, and their increased abundance is associated with poor patient survival. Given the multi-faceted role of macrophages in promoting pancreatic tumor development and progression, these cells represent promising targets for anti-cancer therapy.

Abstract

Pancreatic ductal adenocarcinoma (PDAC) is an aggressive malignant disease with a 5-year survival rate of less than 10%. Macrophages are one of the earliest infiltrating cells in the pancreatic tumor microenvironment, and are associated with an increased risk of disease progression, recurrence, metastasis, and shorter overall survival. Pre-clinical studies have demonstrated an unequivocal role of macrophages in PDAC by contributing to chronic inflammation, cancer cell stemness, desmoplasia, immune suppression, angiogenesis, invasion, metastasis, and drug resistance. Several macrophage-targeting therapies have also been investigated in pre-clinical models, and include macrophage depletion, inhibiting macrophage recruitment, and macrophage reprogramming. However, the effectiveness of these drugs in pre-clinical models has not always translated into clinical trials. In this review, we discuss the molecular mechanisms that underpin macrophage heterogeneity within the pancreatic tumor microenvironment, and examine the contribution of macrophages at various stages of PDAC progression. We also provide a comprehensive update of macrophage-targeting therapies that are currently undergoing clinical evaluation, and discuss clinical challenges associated with these treatment modalities in human PDAC patients.

Role of R-spondin 2 in arterial lymphangiogenesis and atherosclerosis

AIMS

Impaired lymphatic drainage of the arterial wall results in intimal lipid accumulation and atherosclerosis. However, the mechanisms regulating lymphangiogenesis in atherosclerotic arteries are not well understood. Our studies identified elevated levels of matrix protein R-spondin 2 (RSPO2) in atherosclerotic arteries. In this study, we investigated the role of RSPO2 in lymphangiogenesis, arterial cholesterol efflux into lesion-draining lymph nodes (LNs) and development of atherosclerosis.

METHODS AND RESULTS

The effect of RSPO2 on lymphangiogenesis was investigated using human lymphatic endothelial cells (LEC) in vitro and implanted Matrigel plugs in vivo. Cellular and molecular approaches, pharmacological agents, and siRNA silencing of RSPO2 receptor LGR4 were used to investigate RSPO2-mediated signalling in LEC. In vivo low-density lipoprotein (LDL) tracking and perivascular blockade of RSPO2-LGR4 signalling using LGR4-extracellular domain (ECD) pluronic gel in hypercholesterolemic mice were utilized to investigate the role of RSPO2 in arterial reverse cholesterol transport and atherosclerosis. Immunoblotting and imaging experiments demonstrated increased RSPO2 expression in human and mouse atherosclerotic arteries compared to non-atherosclerotic controls. RSPO2 treatment inhibited lymphangiogenesis both in vitro and in vivo. LGR4 silencing and inhibition of RSPO2-LGR4 signalling abrogated RSPO2-induced inhibition of lymphangiogenesis. Mechanistically, we found that RSPO2 suppresses PI3K-AKT-endothelial nitric oxide synthase (eNOS) signalling via LGR4 and inhibits activation of the canonical Wnt-β-catenin pathway. ApoE-/- mice treated with LGR4-ECD developed significantly less atherosclerosis compared with control treatment. Finally, increased arterial lymphatic vessel density and improved lymphatic drainage of fluorescently labelled LDL to deep cervical LNs were observed in LGR4-ECD-treated mice.

CONCLUSION

These findings demonstrate that RSPO2 inhibits lymphangiogenesis via LGR4 and downstream impairment of AKT-eNOS-nitric oxide signalling. These results may also inform new therapeutic strategies to promote lymphangiogenesis and improve cholesterol efflux from atherosclerotic arteries.

Cancer-Associated Fibroblasts as Players in Cancer Development and Progression and Their Role in Targeted Radionuclide Imaging and Therapy

Cancer Associated Fibroblasts (CAFs) form a major component of the tumour microenvironment, they have a complex origin and execute diverse functions in tumour development and progression. As such, CAFs constitute an attractive target for novel therapeutic interventions that will aid both diagnosis and treatment of various cancers. There are, however, a few limitations in reaching successful translation of CAF targeted interventions from bench to bedside. Several approaches targeting CAFs have been investigated so far and a few CAF-targeting tracers have successfully been developed and applied. This includes tracers targeting Fibroblast Activation Protein (FAP) on CAFs. A number of FAP-targeting tracers have shown great promise in the clinic. In this review, we summarize our current knowledge of the functional heterogeneity and biology of CAFs in cancer. Moreover, we highlight the latest developments towards theranostic applications that will help tumour characterization, radioligand therapy and staging in cancers with a distinct CAF population.

Polysaccharides From Lentinus Edodes Inhibits Lymphangiogenesis via the Toll-Like Receptor 4/JNK Pathway of Cancer-Associated Fibroblasts

Polysaccharides from Lentinus edodes (L. edodes) have been successfully used as adjuvant chemotherapy drug to treat lymphatic metastasis in some malignancies, such as colorectal cancer (CRC), lung cancer and gastric cancer. The CRC could metastasize via lymphatic vessels. Lymphatic metastasis is commonly thought to be the cause of poor prognosis of CRC. The mechanism of polysaccharides from L. edodes inhibiting lymphatic metastasis of CRC is still unclear. In this study, we explored how MPSSS, a novel polysaccharide component of L. edodes, influences lymphangiogenesis and lymph node metastasis. The results show that MPSSS can reduce lymphangiogenesis and lymphatic metastasis of CRC in mouse model. And combined with in vitro study, a likely mechanism is that MPSSS reduce the secretion of VEGF-C by cancer associated fibroblasts (CAFs). This effect can be suppressed by a TLR4 inhibitor, which suggests that MPSSS plays a role in CAFs through the TLR4/JNK signaling pathway. In conclusion, MPSSS may reduce lymphangiogenesis by decreasing the VEGF-C secretion of CAFs, which may provide a new strategy for the comprehensive treatment of CRC.

Tumor-associated macrophages: potential therapeutic strategies and future prospects in cancer

Macrophages are the most important phagocytes in vivo. However, the tumor microenvironment can affect the function and polarization of macrophages and form tumor-associated macrophages (TAMs). Usually, the abundance of TAMs in tumors is closely associated with poor prognosis. Preclinical studies have identified important pathways regulating the infiltration and polarization of TAMs during tumor progression. Furthermore, potential therapeutic strategies targeting TAMs in tumors have been studied, including inhibition of macrophage recruitment to tumors, functional repolarization of TAMs toward an antitumor phenotype, and other therapeutic strategies that elicit macrophage-mediated extracellular phagocytosis and intracellular destruction of cancer cells. Therefore, with the increasing impact of tumor immunotherapy, new antitumor strategies to target TAMs are now being discussed.

The role of tumor-associated macrophages in primary hepatocellular carcinoma and its related targeting therapy

Liver macrophages consist of ontogenically distinct populations termed Kupffer cells and monocyte-derived macrophages. Tumor-associated macrophages (TAMs) inhepatocellularcarcinoma (HCC) play a prominent role in tumormicroenvironment by presenting M1(induced by IFN γ along with LPS) and M2(induced by IL-4 and IL13) polarization. Although TAMs are involved in tumor immune surveillance during the course of HCC, they contribute to tumour progression at different levels by inhibiting the anti-tumor immune response, promoting the generation of blood vessels and lymphatic vessels, and supporting the proliferation and survival of tumor cells. In this paper, the multiple functions of TAMs in HCC were reviewed to provide assistance for future researches about therapeutic approaches.

Role of Autophagy in the Microenvironment of Oral Squamous Cell Carcinoma

Oral squamous cell carcinoma, the most common type of oral cancer, affects more than 275,000 people per year worldwide. Oral squamous cell carcinoma is very aggressive, as most patients die after 3 to 5 years post-diagnosis. The initiation and progression of oral squamous cell carcinoma are multifactorial: smoking, alcohol consumption, and human papilloma virus infection are among the causes that promote its development. Although oral squamous cell carcinoma involves abnormal growth and migration of oral epithelial cells, other cell types such as fibroblasts and immune cells form the carcinoma niche. An underlying inflammatory state within the oral tissue promotes differential stress-related responses that favor oral squamous cell carcinoma. Autophagy is an intracellular degradation process that allows cancer cells to survive under stress conditions. Autophagy degrades cellular components by sequestering them in vesicles called autophagosomes, which ultimately fuse with lysosomes. Although several autophagy markers have been associated with oral squamous cell carcinoma, it remains unclear whether up- or down-regulation of autophagy favors its progression. Autophagy levels during oral squamous cell carcinoma are both timing- and cell-specific. Here we discuss how autophagy is required to establish a new cellular microenvironment in oral squamous cell carcinoma and how autophagy drives the phenotypic change of oral squamous cell carcinoma cells by promoting crosstalk between carcinoma cells, fibroblasts, and immune cells.

Angiogenesis in Patients with Chronic Heart Failure: Focus on Endothelial Vascular Growth Factor, Pentraxin-3 and Transforming Growth Factor Beta

Chronic heart failure (CHF) is considered the leading cause of death in patients with established cardiovascular (CVD) and metabolic diseases. Although the current treatment strategy has improved survival and clinical outcomes, the prevalence of CHF shows an increase. Current clinical guidelines for the treatment and prevention of CVD note the role of biological markers as a fairly simple and powerful tool for diagnosing, stratifying risk and predicting CHF. However, it is unclear whether all of these biological markers are equally capable of predicting cardiovascular mortality and heart failure related outcomes in patients with acute and chronic heart failure, as well as in different phenotypes of heart failure. However, the results of numerous studies demonstrate scientific interest in the processes of angiogenesis among patients with CHF. There is an impressive body of evidence linking CHF to the level of markers such as vascular endothelial growth factor, pentraxin-3, and transforming growth factor beta. The review presents the data of domestic and foreign clinical studies devoted to the study of the level of angiogenesis markers among patients with CHF.

Fractalkine/CX3CL1 in Neoplastic Processes

Fractalkine/CX3C chemokine ligand 1 (CX3CL1) is a chemokine involved in the anticancer function of lymphocytes-mainly NK cells, T cells and dendritic cells. Its increased levels in tumors improve the prognosis for cancer patients, although it is also associated with a poorer prognosis in some types of cancers, such as pancreatic ductal adenocarcinoma. This work focuses on the 'hallmarks of cancer' involving CX3CL1 and its receptor CX3CR1. First, we describe signal transduction from CX3CR1 and the role of epidermal growth factor receptor (EGFR) in this process. Next, we present the role of CX3CL1 in the context of cancer, with the focus on angiogenesis, apoptosis resistance and migration and invasion of cancer cells. In particular, we discuss perineural invasion, spinal metastasis and bone metastasis of cancers such as breast cancer, pancreatic cancer and prostate cancer. We extensively discuss the importance of CX3CL1 in the interaction with different cells in the tumor niche: tumor-associated macrophages (TAM), myeloid-derived suppressor cells (MDSC) and microglia. We present the role of CX3CL1 in the development of active human cytomegalovirus (HCMV) infection in glioblastoma multiforme (GBM) brain tumors. Finally, we discuss the possible use of CX3CL1 in immunotherapy.

Expression profile analysis identifies IER3 to predict overall survival and promote lymph node metastasis in tongue cancer

Background

Lymph node metastasis is one of the most important factors affecting the prognosis of tongue cancer, and the molecular mechanism regulating lymph node metastasis of tongue cancer is poorly known.

Methods

The gene expression dataset GSE2280 and The Cancer Genome Atlas (TCGA) tongue cancer dataset were downloaded. R software was used to identify the differentially expressed hallmark gene sets and individual genes between metastatic lymph node tissues and primary tongue cancer tissues, and the Kaplan-Meier method was used to evaluate the association with overall survival. The screening and validation of functional genes was performed using western blot, q-PCR, CCK-8, migration and invasion assays, and lymphangiogenesis was examined by using a tube formation assay.

Results

Thirteen common hallmark gene sets were found based on Gene Set Variation Analysis (GSVA) and then subjected to differential gene expression analysis, by which 76 deregulated genes were found. Gene coexpression network analysis and survival analysis further confirmed that IER3 was the key gene associated with the prognosis and lymph node metastasis of tongue cancer patients. Knockdown of IER3 with siRNA inhibited the proliferation, colony formation, migration and invasion of Tca-8113 cells in vitro and it also inhibited the secretion and expression of VEGF-C in these cells. The culture supernatant of Tca-8113 cells could promote lymphangiogenesis and migration of lymphatic endothelial cells, and knockdown of IER3 in Tca-8113 cells suppressed these processes.

Conclusion

Our study demonstrated that IER3 plays important roles in lymphangiogenesis regulation and prognosis in tongue cancer and might be a potential therapeutic target.

Role of cancer-associated fibroblasts in tumor structure, composition and the microenvironment in ovarian cancer

Ovarian cancer (OVAC) remains the most lethal gynecological malignancy; it is ranked fifth among the most common types of cancer that affect women worldwide. Several aspects of the disease, including molecular pathogenesis, epidemiology, histological subtypes, poor prognosis at early stages due to the absence of specific signs and symptoms, and curative treatments in the advanced stages are all responsible for the poor survival rate, which is evaluated to be at 5 years once the cancer is diagnosed and treatment begins. A better understanding of the pathogenesis of ovarian cancer is therefore crucial, even though unexplored pathways, in order to improve the prognosis of patients with OVAC and to develop novel therapeutic approaches. Accordingly, the tumor microenvironment, defined as the combination of proteins produced by all tumor cells and by non-cancerous cells or the stroma, and composed of several cells, including those from the immune, inflammatory and adipose systems, as well as the mesenchymal stem, endothelial and fibroblasts cells, has recently attracted attention. Of particular interest are fibroblasts, which can be activated into cancer-associated fibroblast (CAFs) to become a potent supporter of carcinogenesis, promoting the initiation of epithelial tumor formation, tumor growth, angiogenesis and metastasis, as well as therapeutic resistance and immunosuppression. Thus, the targeting of CAFs for early diagnosis and effective therapy warrants our attention. In this review, we discuss the mechanisms through which CAFs may affect the structure, composition and microenvironment of the ovarian tumor. We also aim to highlight important aspects of OVAC pathobiology involving CAFs, in an attempt to provide insight into novel diagnostic windows and provide new therapeutic perspectives.

Peptide P11 suppresses the growth of human thyroid carcinoma by inhibiting the PI3K/AKT/mTOR signaling pathway

Thyroid carcinoma is the most common endocrine malignancy, and the incidence of thyroid carcinoma is increasing in recent decades. CYYGQSKYC (P6), a nonapeptide with anti-lymphangiogenic effect by its binding to VEGFR-3 and selectively inhibiting VEGF-C binding to VEGFR-3, could suppress the migration and invasion of cancer cells. LSPPRYP (P9) acts as an effective bFGF/FGFR antagonist and inhibits the growth of the murine melanoma B16-F10 cells. In order to increase the anti-tumor effects of P6 and P9, we connected P6 with P9 via a flexible linker Gly-Gly-Gly (GGG) to reconstruct a novel peptide P11, CYYGQSKYCGGGLSPPRYP. In the present study, the mechanism of action of peptide P11 on the growth of human thyroid carcinoma cells both in vitro and in vivo was determined. Our results showed that peptide P11 inhibited the proliferation, viability, migration, and invasion of human thyroid carcinoma cells. Peptide P11 increased the apoptosis and decreased the protein levels of p-PI3K, p-AKT, and p-mTOR in human thyroid carcinoma cells. In addition, P11 could effectively inhibit the growth of human thyroid carcinoma xenograft tumors in nude mice. In conclusion, peptide P11 could inhibit the growth of human thyroid carcinoma by inhibiting the PI3K/Akt/mTOR signaling pathway. Novel peptides can be designed and applied for the treatment of various types of cancer.

Effect of exosomal miRNA on cancer biology and clinical applications

Exosomes, extracellular vesicles with diameters ranging from 30 to 150 nm, are widely present in various body fluids. Recently, microRNAs (miRNAs) have been identified in exosomes, the biogenesis, release, and uptake of which may involve the endosomal sorting complex required for transport (ESCRT complex) and relevant proteins. After release, exosomes are taken up by neighboring or distant cells, and the miRNAs contained within modulate such processes as interfering with tumor immunity and the microenvironment, possibly facilitating tumor growth, invasion, metastasis, angiogenesis and drug resistance. Therefore, exosomal miRNAs have a significant function in regulating cancer progression. Here, we briefly review recent findings regarding tumor-derived exosomes, including RNA sorting and delivering mechanism. We then describe the intercommunication occurring between different cells via exosomal miRNAs in tumor microenvironmnt, with impacts on tumor proliferation, vascularization, metastasis and other biological characteristics. Finally, we highlight the potential role of these molecules as biomarkers in cancer diagnosis and prognosis and tumor resistance to therapeutics.

Alternagin-C binding to α2β1 integrin controls matrix metalloprotease-9 and matrix metalloprotease-2 in breast tumor cells and endothelial cells

Background

Matrix metalloproteinases (MMPs) are key players in tumor progression, helping tumor cells to modify their microenvironment, which allows cell migration to secondary sites. The role of integrins, adhesion receptors that connect cells to the extracellular matrix, in MMP expression and activity has been previously suggested. However, the mechanisms by which integrins control MMP expression are not completely understood. Particularly, the role of α2β1 integrin, one of the major collagen I receptors, in MMP activity and expression has not been studied. Alternagin-C (ALT-C), a glutamate-cysteine-aspartate-disintegrin from Bothrops alternatus venom, has high affinity for an α2β1 integrin. Herein, we used ALT-C as a α2β1 integrin ligand to study the effect of ALT-C on MMP-9 and MMP-2 expression as well as on tumor cells, fibroblats and endothelial cell migration.

Methods

ALT-C was purified by two steps of gel filtration followed by anion exchange chromatography. The α₂β₁ integrin binding properties of ALT-C, its dissociation constant (K_d) relative to this integrin and to collagen I (Col I) were determined by surface plasmon resonance. The effects of ALT-C (10, 40, 100 and 1000 nM) in migration assays were studied using three human cell lines: human fibroblasts, breast tumor cell line MDA-MB-231, and microvascular endothelial cells HMEC-1, considering cells found in the tumor microenvironment. ALT-C effects on MMP-9 and MMP-2 expression and activity were analyzed by quantitative PCR and gelatin zymography, respectively. Focal adhesion kinase activation was determined by western blotting.

Results

Our data demonstrate that ALT-C, after binding to α₂β₁ integrin, acts by two distinct mechanisms against tumor progression, depending on the cell type: in tumor cells, ALT-C decreases MMP-9 and MMP-2 contents and activity, but increases focal adhesion kinase phosphorylation and transmigration; and in endothelial cells, ALT-C inhibits MMP-2, which is necessary for tumor angiogenesis. ALT-C also upregulates c-Myc mRNA level, which is related to tumor suppression.

Conclusion

These results demonstrate that α₂β₁ integrin controls MMP expression and reveal this integrin as a target for the development of antiangiogenic and antimetastatic therapies.

Electronic supplementary material

The online version of this article (10.1186/s40409-018-0150-2) contains supplementary material, which is available to authorized users.

Contribution to Tumor Angiogenesis From Innate Immune Cells Within the Tumor Microenvironment: Implications for Immunotherapy

The critical role of angiogenesis in promoting tumor growth and metastasis is strongly established. However, tumors show considerable variation in angiogenic characteristics and in their sensitivity to antiangiogenic therapy. Tumor angiogenesis involves not only cancer cells but also various tumor-associated leukocytes (TALs) and stromal cells. TALs produce chemokines, cytokines, proteases, structural proteins, and microvescicles. Vascular endothelial growth factor (VEGF) and inflammatory chemokines are not only major proangiogenic factors but are also immune modulators, which increase angiogenesis and lead to immune suppression. In our review, we discuss the regulation of angiogenesis by innate immune cells in the tumor microenvironment, specific features, and roles of major players: macrophages, neutrophils, myeloid-derived suppressor and dendritic cells, mast cells, γδT cells, innate lymphoid cells, and natural killer cells. Anti-VEGF or anti-inflammatory drugs could balance an immunosuppressive microenvironment to an immune permissive one. Anti-VEGF as well as anti-inflammatory drugs could therefore represent partners for combinations with immune checkpoint inhibitors, enhancing the effects of immune therapy.

Macrophage Polarization in Chronic Inflammatory Diseases: Killers or Builders?

Macrophages are key cellular components of the innate immunity, acting as the main player in the first-line defence against the pathogens and modulating homeostatic and inflammatory responses. Plasticity is a major feature of macrophages resulting in extreme heterogeneity both in normal and in pathological conditions. Macrophages are not homogenous, and they are generally categorized into two broad but distinct subsets as either classically activated (M1) or alternatively activated (M2). However, macrophages represent a continuum of highly plastic effector cells, resembling a spectrum of diverse phenotype states. Induction of specific macrophage functions is closely related to the surrounding environment that acts as a relevant orchestrator of macrophage functions. This phenomenon, termed polarization, results from cell/cell, cell/molecule interaction, governing macrophage functionality within the hosting tissues. Here, we summarized relevant cellular and molecular mechanisms driving macrophage polarization in "distant" pathological conditions, such as cancer, type 2 diabetes, atherosclerosis, and periodontitis that share macrophage-driven inflammation as a key feature, playing their dual role as killers (M1-like) and/or builders (M2-like). We also dissect the physio/pathological consequences related to macrophage polarization within selected chronic inflammatory diseases, placing polarized macrophages as a relevant hallmark, putative biomarkers, and possible target for prevention/therapy.

Lymphatics-associated genes are downregulated at transcription level in non-small cell lung cancer

The present study aimed to verify a possibility of ongoing lymphangiogenesis in non-small cell lung cancer (NSCLC) via examination of mRNA levels of a number of lymphangiogenesis-associated genes in tumors. It was hypothesized that transcriptional activation of these genes would occur in tumors that stimulate new lymphatic vessel formation. The study was performed on 140 pairs of fresh-frozen surgical specimens of cancer and unaffected lung tissues derived from NSCLC stage I-IIIA patients. mRNA levels were evaluated with the reverse transcription-quantitative polymerase chain reaction method and expressed as fold change differences between the tumor and normal tissues. Possible associations between expression and patient clinicopathological characteristics and survival were analyzed. In the NSCLC tissue samples, vascular endothelial growth factor (VEGF) C, VEGFD, VEGFR3, VEGFR2, VEGFR1, lymphatic vessel endothelial hyaluronan receptor 1, integrin subunit α 9, FOX2, neuropilin 2, fibroblast growth factor 2 genes were significantly downregulated (P<0.001 for all) compared with matched normal lung tissues, whereas mRNA levels for VEGFA, spleen associated tyrosine kinase, podoplanin, and prospero homeobox 1 genes were similar in both tissues. Neither lymph node status, nor disease pathological stage influenced expression, whereas more profound suppression of gene activities appeared to occur in squamous cell carcinomas compared with adenocarcinomas. The VEGFR1 mRNA expression level was significantly connected with patient survival in the univariate analysis, and was an independent prognostic factor for overall survival in the multivariate Cox's proportional hazards model (HR 2.103; 95% confidence interval: 1.005-4.401; P=0.049). The results support a hypothesis of absence of new lymphatic vessel formation inside growing NSCLC tumor mass, however do not exclude a possibility of lymphangiogenesis in narrow marginal tumor parts.

Filamin A interacting protein 1-like expression inhibits progression in colorectal cancer

Filamin A interacting protein 1-like (FILIP1L) expression, which is decreased in various cancers, may inhibit carcinogenesis. In this study, we evaluated the effects of FILIP1L on oncogenic behavior and prognosis in colorectal cancer. siRNA-mediated FILIP1L knockdown enhanced tumor cell migration and invasion and inhibited apoptosis and cell cycle arrest in COLO205 cells. pcDNA-myc vector-mediated FILIP1L overexpression suppressed tumor cell migration and invasion and induced apoptosis and cell cycle arrest in HCT116 cells. FILIP1L knockdown enhanced angiogenesis by increasing VEGF-A and HIF-1α levels and decreasing angiostatin level. FILIP1L overexpression suppressed angiogenesis by decreasing VEGF-A and -D l level and increasing angiostatin and endostatin levels. Phosphorylated β-catenin levels decreased and phosphorylated Akt and GSK-3β levels increased following FILIP1L knockdown. FILIP1L overexpression had the opposite effects. FILIP1L expression was associated with reductions in tumor size, cell differentiation, lymphovascular invasion, stage, invasion depth and lymph node metastasis, and with longer overall survival. Mean Ki-67 labeling indexes and microvessel density values were lower in FILIP1L-positive tumors than in FILIP1L-negative tumors. These results indicate that FILIP1L suppresses tumor progression by inhibiting cell proliferation and angiogenesis in colorectal cancer.

Fucoidan inhibits lymphangiogenesis by downregulating the expression of VEGFR3 and PROX1 in human lymphatic endothelial cells

Lymphangiogenesis is one of the promoters of tumor lymphatic metastasis. Fucoidan which is a fucose-enriched sulfated polysaccharide has effect on various pharmacological activities including anti-metastasis activity. However, the inhibitory effect of fucoidan on lymphangiogenesis remains unclear. Here, fucoidan extracted from U. pinnatifida sporophylls suppressed HLECs proliferation, migration and tube-like structure formation, and had inhibitory effect of tumor-induced lymphangiogenesis in vitro. Additionally, we found that fucoidan had a dose-dependent depressive effect on the expressions of PROX1, vascular endothelial growth factor receptor 3 (VEGFR3), NF-κB, phospho-PI3K and phospho-Akt in HLECs. Moreover, anti-lymphangiogenesis effect of fucoidan was assessed by using mouse tumor model. In summary, fucoidan inhibit tumor lymphangiogenesis and lymphatic metastasis by suppressing the NF-κB/PI3K/Akt signaling pathway through reduced levels of PROX1 and VEGFR3.

Utilizing Zebrafish to Identify Anti-(Lymph)Angiogenic Compounds for Cancer Treatment: Promise and Future Challenges

Cancer metastasis which predominantly occurs through blood and lymphatic vessels, is the leading cause of death in cancer patients. Consequently, several anti-angiogenic agents have been approved as therapeutic agents for human cancers such as metastatic renal cell carcinoma. Also, anti-lymphangiogenic drugs such as monoclonal antibodies VGX-100 and IMC-3C5 have undergone phase I clinical trials for advanced and metastatic solid tumors. Although anti-tumor-associated angiogenesis has proven to be a promising therapeutic strategy for human cancers, this approach is fraught with toxicities and development of drug resistance. This emphasizes the need for alternative anti-(lymph)angiogenic drugs. The use of zebrafish has become accepted as an established model for high-throughput screening, vascular biology, and cancer research. Importantly, various zebrafish transgenic lines have now been generated that can readily discriminate different vascular compartments. This now enables detailed in vivo studies that are relevant to both human physiological and tumor (lymph)angiogenesis to be conducted in zebrafish. This review highlights recent advancements in the zebrafish anti-vascular screening platform and showcases promising new anti-(lymph)angiogenic compounds that have been derived from this model. In addition, this review discusses the promises and challenges of the zebrafish model in the context of anti-(lymph)angiogenic compound discovery for cancer treatment.

Macrophage Polarization in Chronic Inflammatory Diseases: Killers or Builders?

Macrophages are key cellular components of the innate immunity, acting as the main player in the first-line defence against the pathogens and modulating homeostatic and inflammatory responses. Plasticity is a major feature of macrophages resulting in extreme heterogeneity both in normal and in pathological conditions. Macrophages are not homogenous, and they are generally categorized into two broad but distinct subsets as either classically activated (M1) or alternatively activated (M2). However, macrophages represent a continuum of highly plastic effector cells, resembling a spectrum of diverse phenotype states. Induction of specific macrophage functions is closely related to the surrounding environment that acts as a relevant orchestrator of macrophage functions. This phenomenon, termed polarization, results from cell/cell, cell/molecule interaction, governing macrophage functionality within the hosting tissues. Here, we summarized relevant cellular and molecular mechanisms driving macrophage polarization in “distant” pathological conditions, such as cancer, type 2 diabetes, atherosclerosis, and periodontitis that share macrophage-driven inflammation as a key feature, playing their dual role as killers (M1-like) and/or builders (M2-like). We also dissect the physio/pathological consequences related to macrophage polarization within selected chronic inflammatory diseases, placing polarized macrophages as a relevant hallmark, putative biomarkers, and possible target for prevention/therapy.

Angiogenesis for tumor vascular normalization of Endostar on hepatoma 22 tumor-bearing mice is involved in the immune response

Tumor vascular normalization involved in immune response is beneficial to the chemotherapy of tumors. Recombinant human endostatin (Endostar), an angiogenesis inhibitor, has been demonstrated to be effective in hepatocellular cancer (HCC). However, its vascular normalization in HCC and the role of the immune response in angiogenesis were unclear. In the present study, effects of Endostar on tumor vascular normalization were evaluated in hepatoma 22 (H22) tumor-bearing mice. Endostar was able to inhibit the proliferation and infiltration of tumor cells and improve α-fetoprotein, tumor necrosis factor-α and cyclic adenosine 5′-phosphate levels in the serum of H22-bearing mice, as well as the protein expression levels of the immune factors interferon-γ and cluster of differentiation (CD)86 in liver tissue. Endostar also exhibited more marked downregulation of the levels of vascular endothelial growth factor, CD31, matrix metalloproteinase (MMP)-2, MMP-9 and interleukin-17 during day 3–9 treatment, resulting in short-term normalization of tumor blood vessels. The period of vascular normalization was 3–9 days. The results of the present study demonstrated that Endostar was able to induce the period of vascular normalization, contributing to a more efficacious means of HCC treatment combined with other chemotherapy, and this effect was associated with the immune response. It may be concluded that Endostar inhibited immunity-associated angiogenesis behaviors of vascular endothelial cells in response to HCC. The results of the present study provided more reasonable possibility for the combination therapy of Endostar for the treatment of HCC.

Effects of diphyllin as a novel V-ATPase inhibitor on TE-1 and ECA-109 cells

Diphyllin is a natural component of traditional Chinese medicine, which effectively inhibits V-ATPase activity and affects the progression of cancer. However, few studies have been conducted on esophageal cancer, and the mechanisms remain to be elucidated. The present study revealedthat diphyllin inhibited proliferation and induced S arrest in esophageal cancer cell lines TE-1 and ECA-109. Further experiments revealed that diphyllin inhibited V-ATPase activity and decreased the mRNA expression of mammalian target of rapamycin complex 1 (mTORC1), hypoxia-inducible factor-1α (HIF-1α), and vascular endothelial growth factor (VEGF). The present study also revealed that diphyllin inhibited proliferation and reduced the formation of new blood vessels. Diphyllin inhibited blood metastasis by regulating the mTORC1/HIF-1α-/VEGF pathway, therefore it could be considered as a new V-ATPase inhibitor to treat esophageal cancer.

Antiangiogenic Effect of Flavonoids and Chalcones: An Update

Chalcones are precursors of flavonoid biosynthesis in plants. Both flavonoids and chalcones are intensively investigated because of a large spectrum of their biological activities. Among others, anticancer and antiangiogenic effects account for the research interest of these substances. Because of an essential role in cancer growth and metastasis, angiogenesis is considered to be a promising target for cancer treatment. Currently used antiangiogenic agents are either synthetic compounds or monoclonal antibodies. However, there are some limitations of their use including toxicity and high price, making the search for new antiangiogenic compounds very attractive. Nowadays it is well known that several natural compounds may modulate basic steps in angiogenesis. A lot of studies, also from our lab, showed that phytochemicals, including polyphenols, are potent modulators of angiogenesis. This review paper is focused on the antiangiogenic effect of flavonoids and chalcones and discusses possible underlying cellular and molecular mechanisms.

IL-3R-alpha blockade inhibits tumor endothelial cell-derived extracellular vesicle (EV)-mediated vessel formation by targeting the β-catenin pathway

The proangiogenic cytokine Interleukin-3 (IL-3) is released by inflammatory cells in breast and ovarian cancer tissue microenvironments and also acts as an autocrine factor for human breast and kidney tumor-derived endothelial cells (TECs). We have previously shown that IL-3-treated endothelial cells (ECs) release extracellular vesicles (EVs), which serve as a paracrine mechanism for neighboring ECs, by transferring active molecules. The impact of an anti-IL-3R-alpha blocking antibody on the proangiogenic effect of EVs released from TECs (anti-IL-3R-EVs) has therefore been investigated in this study. We have found that anti-IL-3R-EV treatment prevented neovessel formation and, more importantly, also induced the regression of in vivo TEC-derived neovessels. Two miRs that target the canonical wingless (Wnt)/β-catenin pathway, at different levels, were found to be differentially regulated when comparing the miR-cargo of naive TEC-derived EVs (EVs) and anti-IL-3R-EVs. miR-214-3p, which directly targets β-catenin, was found to be upregulated, whereas miR-24-3p, which targets adenomatous polyposis coli (APC) and glycogen synthase kinase-3β (GSK3β), was found to be downregulated. In fact, upon their transfer into the cell, low β-catenin content and high levels of the two members of the “β-catenin destruction complex” were detected. Moreover, c-myc downregulation was found in TECs treated with anti-IL-3R-EVs, pre-miR-214-3p-EVs and antago-miR-24-3p-EVs, which is consistent with network analyses of miR-214-3p and miR-24-3p gene targeting. Finally, in vivo studies have demonstrated the impaired growth of vessels in pre-miR-214-3p-EV- and antago-miR-24-3p-EV-treated animals. These effects became much more evident when combo treatment was applied. The results of the present study identify the canonical Wnt/β-catenin pathway as a relevant mechanism of TEC-derived EV proangiogenic action. Furthermore, we herein provide evidence that IL-3R blockade may yield some significant advantages, than miR targeting, in inhibiting the proangiogenic effects of naive TEC-derived EVs by changing TEC-EV-miR cargo.

Macrophages and prognosis of oral squamous cell carcinoma: A systematic review

Oral Squamous Cell Carcinoma (OSCC) presents a tumor microenvironment rich in inflammatory cells. Depending on the stimulus, macrophages can polarize in M1 or M2 profile, where M1 acts as proinflammatory and antitumor, and M2 is anti-inflammatory and shows protumor activity. Several studies have shown that macrophages are important to the prognosis of patients with different types of cancer. Our aim was to conduct a systematic review to evaluate the role of macrophages in the prognosis of OSCC patients. A search in the Pubmed, Scopus, and ISI Web of Knowledge database was performed, and it was included only studies that evaluated the importance of macrophages in the prognosis of OSCC patients. From initial 286 articles, 14 fully attended the inclusion criteria. In the majority of the articles, it was evaluated only CD68, a panmacrophage marker, or CD163, a M2 marker. Only one article evaluated the M1 marker, CD11c. Besides, 5 articles analyzed the presence of macrophages in different areas of the tumor. Higher concentrations of CD68 and CD163 were associated with worse survival. In conclusion, macrophages are important to OSCC patients' prognosis; however, it is necessary to address in which tumor region the presence of polarized macrophage is more important to the outcome.

Baicalein inhibits tumor progression by inhibiting tumor cell growth and tumor angiogenesis

Baicalein, a herbal medicine, is a natural flavonoid isolated from the roots of Scutellaria baicalensis Georgi. It is known for its anticancer, anti-inflammatory and neuroprotective properties. Despite these well-known properties, it is not yet clear what effect baicalein has on tumor progression. Therefore, in the present study, we used B16F10 cells, Lewis lung carcinoma (LLC) cells, and human umbilical vein endothelial cells (HUVECs) to investigate the effect of baicalein on cell proliferation and viability, migration and tube formation in vitro. In addition, an experimental animal model was used to observe the growth rate and metastasis of tumors and tumor vessel formation in vivo. Our results showed that baicalein decreased the proliferation and migration and induced tumor cell death via caspase-3 activation in the B16F10 and LLC cells, and strongly inhibited tube formation and cell migration in HUVECs. Furthermore, mouse models showed that baicalein reduced the tumor volume and greatly reduced the tumor growth rate in the early stages of tumor progression, and the baicalein-treated groups had significantly reduced expression of CD31 (endothelial cell marker) and α-SMA (mural cell marker) in the tumors, indicating that baicalein inhibits tumor angiogenesis by disrupting tumor vasculature development. Comparison of the lymph node and lung samples collected from the baicalein-treated group, and the untreated group showed that baicalein reduced metastasis of the tumor to these tissues. In summary, baicalein reduced tumor progression and metastasis, directly induced tumor cell death, and inhibited tumor angiogenesis. Our results strongly demonstrate that baicalein is a potential chemotherapeutic agent.