ASK1-dependent endothelial cell activation is critical in ovarian cancer growth and metastasis

Role of tumor microenvironment in ovarian cancer metastasis and clinical advancements

Ovarian cancer (OC) is the most lethal gynecological malignancy worldwide, characterized by heterogeneity at the molecular, cellular and anatomical levels. Most patients are diagnosed at an advanced stage, characterized by widespread peritoneal metastasis. Despite optimal cytoreductive surgery and platinum-based chemotherapy, peritoneal spread and recurrence of OC are common, resulting in poor prognoses. The overall survival of patients with OC has not substantially improved over the past few decades, highlighting the urgent necessity of new treatment options. Unlike the classical lymphatic and hematogenous metastasis observed in other malignancies, OC primarily metastasizes through widespread peritoneal seeding. Tumor cells (the "seeds") exhibit specific affinities for certain organ microenvironments (the "soil"), and metastatic foci can only form when there is compatibility between the "seeds" and "soil." Recent studies have highlighted the tumor microenvironment (TME) as a critical factor influencing the interactions between the "seeds" and "soil," with ascites and the local peritoneal microenvironment playing pivotal roles in the initiation and progression of OC. Prior to metastasis, the interplay among tumor cells, immunosuppressive cells, and stromal cells leads to the formation of an immunosuppressive pre-metastatic niche in specific sites. This includes characteristic alterations in tumor cells, recruitment and functional anomalies of immune cells, and dysregulation of stromal cell distribution and function. TME-mediated crosstalk between cancer and stromal cells drives tumor progression, therapy resistance, and metastasis. In this review, we summarize the current knowledge on the onset and metastatic progression of OC. We provide a comprehensive discussion of the characteristics and functions of TME related to OC metastasis, as well as its association with peritoneal spread. We also outline ongoing relevant clinical trials, aiming to offer new insights for identifying potential effective biomarkers and therapeutic targets in future clinical practice.

Obesity-associated reduction of miR-150-5p in extracellular vesicles promotes ventilator-induced lung injury by modulating the lysosomal degradation of VE-cadherin

Obese patient has a high risk of ventilator-induced lung injury (VILI) but its underlying mechanisms remain elusive. This study was designed to explore the role of circulating plasma extracellular vesicles (EVs) on the progression of VILI in the context of obesity. After high tidal volume mechanical ventilation, mice treated with plasma EVs from obese patients developed more severe lung damage than mice treated with plasma EVs from normal controls. miRNA sequencing of plasma EVs from obese patients revealed a significant downregulation of miR-150-5p compared to the others. miR-150-5p was found to target on XBP1s which subsequently regulated RAB7 as verified through dual-luciferase assays. This pathway promoted lysosomal degradation of vascular endothelial (VE)-cadherin, leading to an increased endothelial permeability. Obese mice showed an enhanced XBP1s/RAB7 expression, reduced VE-cadherin levels, and aggravated endothelial barrier damage and all of which intensified VILI. Administration of miR-150-5p agomir in obese mice mitigated VILI. Thus, this study highlights the low levels of miR-150-5p in EVs from obese patients modulated VILI severity via the XBP1s/RAB7 axis and the lysosomal degradation of VE-cadherin.

NMN Supplementation Inhibits Endothelial Cell ROS-Mediated Src/Pi3k/Akt Signaling Pathway to Protect High-Altitude Blood-Retinal Barrier

Purpose

High-altitude retinopathy (HAR) is primarily caused by hypobaric hypoxia, leading to hemodynamic changes in the retina and disruption of the blood-retinal barrier (BRB), which results in vasogenic edema. Currently, treatment strategies for this condition are limited. In this study, we investigated the protective effect of nicotinamide mononucleotide (NMN) against high-altitude hypoxia-induced BRB disruption and its potential molecular mechanisms.

Methods

We established a mouse model of high-altitude BRB injury using a simulated high-altitude environment chamber. Vascular leakage was observed through the Evans Blue dye leakage assay, and retinal Nicotinamide adenine dinucleotide (NAD+) levels were measured using the WST-8 assay. Human umbilical vein endothelial cells (HUVECs) were cultured in a hypoxic chamber, and the permeability of a confluent monolayer to FITC-dextran was monitored. With or without NMN intervention, VE-cadherin expression or phosphorylation at cell junctions was analyzed by Western blot and/or immunofluorescence. Apoptosis levels were assessed via Western blot, TUNEL staining, or flow cytometry, whereas reactive oxygen species (ROS) levels were observed using DCFH-DA, MitoSOX, or DHE probes. DNA damage levels were measured using 8-Oxoguanine immunofluorescence staining, and phosphorylation levels of the Src/Pi3k/Akt signaling pathway were analyzed via Western blot.

Results

High-altitude hypoxia led to increased retinal cell apoptosis and significant phosphorylation of VE-cadherin in endothelial cells, which resulted in a marked increase in BRB permeability. Both in vitro and in vivo experiments showed that NMN intervention reduced endothelial cell apoptosis and permeability. Additionally, NMN protected the endothelial barrier by regulating ROS levels in endothelial cells, inhibiting Src phosphorylation, and downregulating the downstream Pi3k/Akt signaling pathway.

Conclusions

These findings establish the role of NMN and the ROS-mediated Src/Pi3k/Akt signaling pathway in protecting the endothelial barrier, and identify a potential therapeutic strategy for protecting against hypoxia-related BRB leakage.

Beyond tumor‑associated macrophages involved in spheroid formation and dissemination: Novel insights for ovarian cancer therapy (Review)

Ovarian cancer (OC) is the most common and deadly malignant tumor of the female reproductive system. When OC cells detach from the primary tumor and enter the ascitic microenvironment, they are present as individual cells or multicellular spheroids in ascites. These spheroids, composed of cancer and non‑malignant cells, are metastatic units and play a crucial role in the progression of OC. However, little is known about the mechanism of spheroid formation and dissemination. Tumor‑associated macrophages (TAMs) in the center of spheroids are key in spheroid formation and metastasis and provide a potential target for OC therapy. The present review summarizes the key biological features of spheroids, focusing on the role of TAMs in spheroid formation, survival and peritoneal metastasis, and the strategies targeting TAMs to provide new insights in treating OC.

ASK-1 activation exacerbates kidney dysfunction via increment of glomerular permeability and accelerates cellular aging in diabetic kidney disease model mice

Diabetic kidney disease (DKD) is a major disease characterized by early albuminuria and heightened risk of renal deterioration. Increased reactive oxygen species (ROS) production, especially in glomeruli, plays an important role in the progression of DKD. ROS also cause activation of Apoptosis signal-regulating kinase 1 (ASK-1), which is implicated in various organ injuries. However, the detailed mechanisms remain unclear. This study investigates ASK-1 activation in advanced DKD and its underlying mechanisms using GS442172, an ASK-1 inhibitor. In the DKD mouse model, activation of ASK-1 was observed. Although inhibition of ASK-1 activation improved hyperpermeability in glomerular endothelial cells. ASK-1 inhibition significantly reduced glomerular injury and albuminuria, while also attenuating tubular damage and interstitial fibrosis. RNA-seq analysis revealed an aging phenotype associated with ASK-1 activation in DKD. In vitro experiments demonstrated ASK-1 activation-induced cellular senescence in tubular cells via redox signaling. These results suggested that the critical role of ASK-1 activation in DKD pathogenesis, implicating glomerular injury, tubular damage, and cellular senescence. ASK-1 inhibitors are promising therapeutic strategies to mitigate the progression of DKD.

Integrated computational approach identifies potential inhibitors of ASK1-(JNK/P38) interaction signaling: new insights into cancer therapeutics

Cancers are characterized by the aberrant expression of certain genes that trigger a cascade of molecular events that culminate in dysregulated cell division. Consequently, the inhibition of the products of these expressedgenes has emerged as a rational approach in cancer therapy. The apoptosis signal-regulating kinase 1 (ASK1) protein, encoded by the mitogen-activated protein kinase kinase kinase 5 (MAP3K5) gene, plays pertinent roles in the mediation of cell death induced by stress and inflammation, andis often found at elevated levels in cancer. Consequently, it has emerged as a molecular target for the development of potential chemotherapeutics through identification of selective inhibitors. However, there is still dearth of ASK1 inhibitors in clinical use. Hence, molecular modelling approaches were employed in this study to discover potential ASK1 inhibitors from phytochemicals. Twenty-five phytocompounds from four medicinal plants were tested for their inhibitory prowess via molecular docking. Interestingly, all the compounds exhibited promising inhibitory potentials for ASK1. However, further subjection to filtering procedures via different pipelines including drug-likeness evaluation, pharmacokinetics screening, toxicity profiling, and better affinities compared to the approved inhibitor resulted in three hit compounds namely ellagic acid, luteolin, and kaempferol with suitable properties. Profiling of the interactions formed between the hit\compounds and the targets revealed several interactions that were not present in that of the approved inhibitor, while molecular dynamics (MD) simulation revealed the complexes formed as stable. Conclusively, this study identified three compounds with ASK1 inhibitory potentials that are worthy of further exploration in in vitro and in vivo studies.Communicated by Ramaswamy H. Sarma.

Tumor Vasculature as an Emerging Pharmacological Target to Promote Anti-Tumor Immunity

Tumor vasculature abnormality creates a microenvironment that is not suitable for anti-tumor immune response and thereby induces resistance to immunotherapy. Remodeling of dysfunctional tumor blood vessels by anti-angiogenic approaches, known as vascular normalization, reshapes the tumor microenvironment toward an immune-favorable one and improves the effectiveness of immunotherapy. The tumor vasculature serves as a potential pharmacological target with the capacity of promoting an anti-tumor immune response. In this review, the molecular mechanisms involved in tumor vascular microenvironment-modulated immune reactions are summarized. In addition, the evidence of pre-clinical and clinical studies for the combined targeting of pro-angiogenic signaling and immune checkpoint molecules with therapeutic potential are highlighted. The heterogeneity of endothelial cells in tumors that regulate tissue-specific immune responses is also discussed. The crosstalk between tumor endothelial cells and immune cells in individual tissues is postulated to have a unique molecular signature and may be considered as a potential target for the development of new immunotherapeutic approaches.

Interaction of tumor‑associated macrophages with stromal and immune components in solid tumors: Research progress (Review)

Tumor‑associated macrophages (TAMs) are crucial cells of the tumor microenvironment (TME), which belong to the innate immune system and regulate primary tumor growth, immunosuppression, angiogenesis, extracellular matrix remodeling and metastasis. The review discusses current knowledge of essential cell‑cell interactions of TAMs within the TME of solid tumors. It summarizes the mechanisms of stromal cell (including cancer‑associated fibroblasts and endothelial cells)‑mediated monocyte recruitment and regulation of differentiation, as well as pro‑tumor and antitumor polarization of TAMs. Additionally, it focuses on the perivascular TAM subpopulations that regulate angiogenesis and lymphangiogenesis. It describes the possible mechanisms of reciprocal interactions of TAMs with other immune cells responsible for immunosuppression. Finally, it highlights the perspectives for novel therapeutic approaches to use combined cellular targets that include TAMs and other stromal and immune cells in the TME. The collected data demonstrated the importance of understanding cell‑cell interactions in the TME to prevent distant metastasis and reduce the risk of tumor recurrence.

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.

Tumor cells-derived conditioned medium induced pro-tumoral phenotypes in macrophages through calcium-nuclear factor κB interaction

BACKGROUND

The malignant behaviors of lung cancers are affected by not only cancer cells but also many kinds of stromal cells in tumor microenvironment (TME), including macrophages. Macrophages have been proven to extensively influence tumor progression through several mechanisms, among which switching of macrophages from pro-inflammatory phenotypes (M1-like) to anti-inflammatory phenotypes (M2-like) mediated by transcription factors such as nuclear factor κB (NF-κB) is the most crucial event. The regulation of NF-κB has been well studied, however some details remain fuzzy.

METHODS

Mouse primary bone marrow-derived macrophages (BMDMs) were cultured in Lewis lung carcinoma cell line LL-2-derived conditioned medium (LL-2-CM). Proliferation, migration, and polarization of BMDMs were tested by CCK8, scratch test, transwell, and flow cytometry. Secretion of several cytokines were detected by ELISA or cytometric bead array. To further explore the underlying mechanisms, BMDMs cultured in LL-2-CM were harvested for RNA-seq. Cytosolic calcium was detected by calcium probe Fluo-4-AM. Western blot was applied to exam the activation of NF-κB signal. BAPTA-AM was applied to sequestrate cytosolic calcium to further investigate the relationship between calcium and NF-κB signal. The polarization, calcium alteration, and NF-κB signal activation were further validated in BMDMs treated by CMT-64-derived conditioned medium (CMT-64-CM).

RESULTS

LL-2-CM promoted proliferation, migration, and M2-like polarization of BMDMs and inhibited M1-like polarization of BMDMs. However two pro-inflammatory cytokines, interleukin-6 (IL-6) and tumor necrosis factor-[Formula: see text] (TNF-[Formula: see text]) were secreted. RNA-seq indicated that LL-2-CM activated both canonical and non-canonical NF-κB signal in BMDMs. Western blot showed that canonical NF-κB was temporarily elicited and attenuated at 24 h, while non-canonical NF-κB was consistently activated. At the same time, expression of genes that regulate cytosolic calcium ion concentration were down regulated, which caused diminution of cytosolic calcium in BMDMs treated with LL-2-CM. The decreased cytosolic calcium, M2-like polarization, and NF-κB activation was also observed in CMT-64-CM treated BMDMs. On the contrary, elevated cytosolic calcium was observed during M1-like polarization of BMDMs elicited by lipopolysaccharide (LPS). Interestingly, administration of calcium chelator, BAPTA-AM, impeded activation of canonical NF-κB and expression of M1-like marker induced by LPS, which further confirmed the relationship between cytosolic calcium and canonical NF-κB signal.

CONCLUSIONS

In summary, lung cancer cell-derived conditioned medium promoted migration, proliferation, and M2-like polarization of BMDMs. The suppressed M1-like polarization was achieved through mitigating canonical NF-κB pathway via diminishing cytosolic calcium concentration. As far as we know, our work firstly revealed that cytosolic calcium is the key during inhibition of canonical NF-κB and M1-like polarization in macrophages by tumor cells.

Targeting VEGF-A/VEGFR2 Y949 Signaling-Mediated Vascular Permeability Alleviates Hypoxic Pulmonary Hypertension

BACKGROUND

Pulmonary hypertension (PH) is associated with increased expression of VEGF-A (vascular endothelial growth factor A) and its receptor, VEGFR2 (vascular endothelial growth factor 2), but whether and how activation of VEGF-A signal participates in the pathogenesis of PH is unclear.

METHODS

VEGF-A/VEGFR2 signal activation and VEGFR2 Y949-dependent vascular leak were investigated in lung samples from patients with PH and mice exposed to hypoxia. To study their mechanistic roles in hypoxic PH, we examined right ventricle systolic pressure, right ventricular hypertrophy, and pulmonary vasculopathy in mutant mice carrying knock-in of phenylalanine that replaced the tyrosine at residual 949 of VEGFR2 (Vefgr2^Y949F) and mice with conditional endothelial deletion of Vegfr2 after chronic hypoxia exposure.

RESULTS

We show that PH leads to excessive pulmonary vascular leak in both patients and hypoxic mice, and this is because of an overactivated VEGF-A/VEGFR2 Y949 signaling axis. In the context of hypoxic PH, activation of Yes1 and c-Src and subsequent VE-cadherin phosphorylation in endothelial cells are involved in VEGFR2 Y949-induced vascular permeability. Abolishing VEGFR2 Y949 signaling by Vefgr2^Y949F point mutation was sufficient to prevent pulmonary vascular permeability and inhibit macrophage infiltration and Rac1 activation in smooth muscle cells under hypoxia exposure, thereby leading to alleviated PH manifestations, including muscularization of distal pulmonary arterioles, elevated right ventricle systolic pressure, and right ventricular hypertrophy. It is important that we found that VEGFR2 Y949 signaling in myeloid cells including macrophages was trivial and dispensable for hypoxia-induced vascular abnormalities and PH. In contrast with selective blockage of VEGFR2 Y949 signaling, disruption of the entire VEGFR2 signaling by conditional endothelial deletion of Vegfr2 promotes the development of PH.

CONCLUSIONS

Our results support the notion that VEGF-A/VEGFR2 Y949-dependent vascular permeability is an important determinant in the pathogenesis of PH and might serve as an attractive therapeutic target pathway for this disease.

Spheroid Formation and Peritoneal Metastasis in Ovarian Cancer: The Role of Stromal and Immune Components

Ovarian cancer (OC) is one of the most common gynecological cancers, with the worst prognosis and the highest mortality rate. Peritoneal dissemination (or carcinomatosis) accompanied by ascites formation is the most unfavorable factor in the progression and recurrence of OC. Tumor cells in ascites are present as either separate cells or, more often, as cell aggregates, i.e., spheroids which promote implantation on the surface of nearby organs and, at later stages, metastases to distant organs. Malignant ascites comprises a unique tumor microenvironment; this fact may be of relevance in the search for new prognostic and predictive factors that would make it possible to personalize the treatment of patients with OC. However, the precise mechanisms of spheroid formation and carcinomatosis are still under investigation. Here, we summarize data on ascites composition as well as the activity of fibroblasts and macrophages, the key stromal and immune components, in OC ascites. We describe current knowledge about the role of fibroblasts and macrophages in tumor spheroid formation, and discuss the specific functions of fibroblasts, macrophages and T cells in tumor peritoneal dissemination and implantation.

Ferroptosis-related genes are candidate diagnostic and prognostic biomarkers for skin cutaneous melanoma

Skin cutaneous melanoma (SKCM) is a disease with the highest mortality rate among skin cancers. As a new type of programmed cell death, ferroptosis has been confirmed to be related to the occurrence and development of a variety of cancers. At present, the expression and prognostic value of ferroptosis-related genes (FRGs) in SKCM are still unclear. In this study, we selected seven FRGs that were differentially expressed in SKCM and related to the patient’s prognosis through the databases. Further studies have shown that these genes are closely related to immune cell infiltration and immune checkpoints. All in all, these seven FRGs may be potential targets for clinical diagnosis, prognosis and treatment of SKCM patients.

A New Antitumor Direction: Tumor-Specific Endothelial Cells

Targeting tumor blood vessels is an important strategy for tumor therapies. At present, antiangiogenic drugs are known to have significant clinical effects, but severe drug resistance and side effects also occur. Therefore, new specific targets for tumor and new treatment methods must be developed. Tumor-specific endothelial cells (TECs) are the main targets of antiangiogenic therapy. This review summarizes the differences between TECs and normal endothelial cells, assesses the heterogeneity of TECs, compares tumorigenesis and development between TECs and normal endothelial cells, and explains the interaction between TECs and the tumor microenvironment. A full and in-depth understanding of TECs may provide new insights for specific antitumor angiogenesis therapies.

Endothelial deletion of SHP2 suppresses tumor angiogenesis and promotes vascular normalization

SHP2 mediates the activities of multiple receptor tyrosine kinase signaling and its function in endothelial processes has been explored extensively. However, genetic studies on the role of SHP2 in tumor angiogenesis have not been conducted. Here, we show that SHP2 is activated in tumor endothelia. Shp2 deletion and pharmacological inhibition reduce tumor growth and microvascular density in multiple mouse tumor models. Shp2 deletion also leads to tumor vascular normalization, indicated by increased pericyte coverage and vessel perfusion. SHP2 inefficiency impairs endothelial cell proliferation, migration, and tubulogenesis through downregulating the expression of proangiogenic SRY-Box transcription factor 7 (SOX7), whose re-expression restores endothelial function in SHP2-knockdown cells and tumor growth, angiogenesis, and vascular abnormalization in Shp2-deleted mice. SHP2 stabilizes apoptosis signal-regulating kinase 1 (ASK1), which regulates SOX7 expression mediated by c-Jun. Our studies suggest SHP2 in tumor associated endothelial cells is a promising anti-angiogenic target for cancer therapy.

The effect of mitochondria-targeted antioxidant MitoQ10 on redox signaling pathway components in PCOS mouse model

PURPOSE

Considerable evidence suggests that mitochondrial dysfunction and oxidative stress contribute to the pathogenesis of Polycystic ovary syndrome (PCOS). We aimed to evaluate the effectiveness of mitochondria-targeted antioxidant, MitoQ10, on the redox signaling pathway's component in PCOS.

METHOD

We assessed TXNIP, TRX, and ASK1 expression in granulosa cells (GCs) of the DHEA-induced PCOS mouse model. Female BALB/c mice in five groups of Control, DHEA, and DHEA + MitoQ10 in three doses of 250, 500, and 750 μmol/L MitoQ10 were treated for 21 days.

RESULTS

Histological investigation showed a probable improvement in folliculogenesis; besides, ASK1 and TXNIP expression were significantly increased in GCs of the PCOS mouse F4Fmodel as compared to the control groups and decreased steadily in groups treated by MitoQ10. However, TRX expression showed a drop that was restored by MitoQ10 meaningfully (P ≤ 0.05).

CONCLUSION

The work presented herein suggests mitochondria-targeted antioxidant, MitoQ10, have modulating effects on folliculogenesis in the ovary and also on the redox signaling pathway in GCs of PCOS mouse model which may have potential to attenuate oxidative stress and its relative damages.

Construction and Validation of a Macrophage-Associated Risk Model for Predicting the Prognosis of Osteosarcoma

Background

Osteosarcoma is one of the most common bone tumors among children. Tumor-associated macrophages have been found to interact with tumor cells, secreting a variety of cytokines about tumor growth, metastasis, and prognosis. This study aimed to identify macrophage-associated genes (MAGs) signatures to predict the prognosis of osteosarcoma.

Methods

Totally 384 MAGs were collected from GSEA software C7: immunologic signature gene sets. Differential gene expression (DGE) analysis was performed between normal bone samples and osteosarcoma samples in GSE99671. Kaplan–Meier survival analysis was performed to identify prognostic MAGs in TARGET-OS. Decision curve analysis (DCA), nomogram, receiver operating characteristic (ROC), and survival curve analysis were further used to assess our risk model. All genes from TARGET-OS were used for gene set enrichment analysis (GSEA). Immune infiltration of osteosarcoma sample was calculated using CIBERSORT and ESTIMATE packages. The independent test data set GSE21257 from gene expression omnibus (GEO) was used to validate our risk model.

Results

5 MAGs (MAP3K5, PML, WDR1, BAMBI, and GNPDA2) were screened based on protein-protein interaction (PPI), DGE, and survival analysis. A novel macrophage-associated risk model was constructed to predict a risk score based on multivariate Cox regression analysis. The high-risk group showed a worse prognosis of osteosarcoma (p < 0.001) while the low-risk group had higher immune and stromal scores. The risk score was identified as an independent prognostic factor for osteosarcoma. MAGs model for diagnosis of osteosarcoma had a better net clinical benefit based on DCA. The nomogram and ROC curve also effectively predicted the prognosis of osteosarcoma. Besides, the validation result was consistent with the result of TARGET-OS.

Conclusions

A novel macrophage-associated risk score to differentiate low- and high-risk groups of osteosarcoma was constructed based on integrative bioinformatics analysis. Macrophages might affect the prognosis of osteosarcoma through macrophage differentiation pathways and bring novel sights for the progression and prognosis of osteosarcoma.

A bi-directional dialog between vascular cells and monocytes/macrophages regulates tumor progression

Cancer progression largely depends on tumor blood vessels as well on immune cell infiltration. In various tumors, vascular cells, namely endothelial cells (ECs) and pericytes, strongly regulate leukocyte infiltration into tumors and immune cell activation, hence the immune response to cancers. Recently, a lot of compelling studies unraveled the molecular mechanisms by which tumor vascular cells regulate monocyte and tumor-associated macrophage (TAM) recruitment and phenotype, and consequently tumor progression. Reciprocally, TAMs and monocytes strongly modulate tumor blood vessel and tumor lymphatic vessel formation by exerting pro-angiogenic and lymphangiogenic effects, respectively. Finally, the interaction between monocytes/TAMs and vascular cells is also impacting several steps of the spread of cancer cells throughout the body, a process called metastasis. In this review, the impact of the bi-directional dialog between blood vascular cells and monocytes/TAMs in the regulation of tumor progression is discussed. All together, these data led to the design of combinations of anti-angiogenic and immunotherapy targeting TAMs/monocyte whose effects are briefly discussed in the last part of this review.

Role of lysosomes in physiological activities, diseases, and therapy

Long known as digestive organelles, lysosomes have now emerged as multifaceted centers responsible for degradation, nutrient sensing, and immunity. Growing evidence also implicates role of lysosome-related mechanisms in pathologic process. In this review, we discuss physiological function of lysosomes and, more importantly, how the homeostasis of lysosomes is disrupted in several diseases, including atherosclerosis, neurodegenerative diseases, autoimmune disorders, pancreatitis, lysosomal storage disorders, and malignant tumors. In atherosclerosis and Gaucher disease, dysfunction of lysosomes changes cytokine secretion from macrophages, partially through inflammasome activation. In neurodegenerative diseases, defect autophagy facilitates accumulation of toxic protein and dysfunctional organelles leading to neuron death. Lysosomal dysfunction has been demonstrated in pathology of pancreatitis. Abnormal autophagy activation or inhibition has been revealed in autoimmune disorders. In tumor microenvironment, malignant phenotypes, including tumorigenesis, growth regulation, invasion, drug resistance, and radiotherapy resistance, of tumor cells and behaviors of tumor-associated macrophages, fibroblasts, dendritic cells, and T cells are also mediated by lysosomes. Based on these findings, a series of therapeutic methods targeting lysosomal proteins and processes have been developed from bench to bedside. In a word, present researches corroborate lysosomes to be pivotal organelles for understanding pathology of atherosclerosis, neurodegenerative diseases, autoimmune disorders, pancreatitis, and lysosomal storage disorders, and malignant tumors and developing novel therapeutic strategies.

ASK1 suppresses NK cell-mediated intravascular tumor cell clearance in lung metastasis

Tumor metastasis is the leading cause of death worldwide and involves an extremely complex process composed of multiple steps. Our previous study demonstrated that apoptosis signal‐regulating kinase 1 (ASK1) deficiency in mice attenuates tumor metastasis in an experimental lung metastasis model. However, the steps of tumor metastasis regulated by ASK1 remain unclear. Here, we showed that ASK1 deficiency in mice promotes natural killer (NK) cell‐mediated intravascular tumor cell clearance in the initial hours of metastasis. In response to tumor inoculation, ASK1 deficiency upregulated immune response‐related genes, including interferon‐gamma (IFNγ). We also revealed that NK cells are required for these anti‐metastatic phenotypes. ASK1 deficiency augmented cytokine production chemoattractive to NK cells possibly through induction of the ligand for NKG2D, a key activating receptor of NK cells, leading to further recruitment of NK cells into the lung. These results indicate that ASK1 negatively regulates NK cell‐dependent anti‐tumor immunity and that ASK1‐targeted therapy can provide a new tool for cancer immunotherapy to overcome tumor metastasis.

Apoptosis signal-regulating kinase 1 inhibition reverses deleterious indoxyl sulfate-mediated endothelial effects

AIMS

Indoxyl sulfate (IS), a protein-bound uremic toxin, is implicated in endothelial dysfunction, which contributes to adverse cardiovascular events in chronic kidney disease. Apoptosis signal regulating kinase 1 (ASK1) is a reactive oxygen species-driven kinase involved in IS-mediated adverse effects. This study assessed the therapeutic potential of ASK1 inhibition in alleviating endothelial effects induced by IS.

MAIN METHODS

IS, in the presence and absence of a selective ASK1 inhibitor (GSK2261818A), was assessed for its effect on vascular reactivity in rat aortic rings, and cultured human aortic endothelial cells where we evaluated phenotypic and mechanistic changes.

KEY FINDINGS

IS directly impairs endothelium-dependent vasorelaxation and endothelial cell migration. Mechanistic studies revealed increased production of reactive oxygen species-related markers, reduction of endothelial nitric oxide synthase and increased protein expression of tissue inhibitor of matrix metalloproteinase 1 (TIMP1). IS also increases angiopoietin-2 and tumour necrosis factor α gene expression and promotes transforming growth factor β receptor abundance. Inhibition of ASK1 ameliorated the increase in oxidative stress markers, promoted autocrine interleukin 8 pro-angiogenic signalling and decreased anti-angiogenic responses at least in part via reducing TIMP1 protein expression.

SIGNIFICANCE

ASK1 inhibition attenuated vasorelaxation and endothelial cell migration impaired by IS. Therefore, ASK1 is a viable intracellular target to alleviate uremic toxin-induced impairment in the vasculature.

MicroRNA-146b-5p overexpression attenuates premature ovarian failure in mice by inhibiting the Dab2ip/Ask1/p38-Mapk pathway and γH2A.X phosphorylation

OBJECTIVE

To examine the role of high-fat and high-sugar (HFHS) diet-induced oxidative stress, which is a risk factor for various diseases, in premature ovarian failure (POF).

MATERIALS AND METHODS

Ovarian granulosa cells (OGCs) were isolated from mice and cultured in medium supplemented with HFHS and poly (lactic-co-glycolic acid) (PLGA)-cross-linked miR-146b-5p nanoparticles (miR-146@PLGA). RNA and protein expression levels were examined using quantitative real-time polymerase chain reaction and Western blotting, respectively. HFHS diet-induced POF model mice were administered miR-146@PLGA.

RESULTS

The ovarian tissue of mice fed a HFHS diet exhibited the typical pathological characteristics of POF. HFHS supplementation induced oxidative stress injury in the mouse OGCs, activation of the Dab2ip/Ask1/p38-Mapk signalling pathway and phosphorylation of γH2A.X in vitro and in vivo. The results of the luciferase reporter assay revealed that miR-146 specifically downregulated p38-Mapk14 expression. Meanwhile, co-immunoprecipitation and Western blot analyses revealed that HFHS supplementation upregulated nuclear p38-Mapk14 expression and consequently enhanced γH2A.X (Ser139) phosphorylation. The HFHS diet-induced POF mouse model treated with miR-146@PLGA exhibited downregulated p38-Mapk14 expression in the OGCs, mitigated OGC ageing and alleviated the symptoms of POF.

CONCLUSIONS

This study demonstrated that HFHS supplementation activates the Dab2ip/Ask1/p38-Mapk signalling pathway and promotes γH2A.X phosphorylation by inhibiting the expression of endogenous miR-146b-5p, which results in OGC ageing and POF development.

ASK1 inhibits proliferation and migration of lung cancer cells via inactivating TAZ

ASK1 (Apoptosis Signal-regulating Kinase 1, also MEKK5) is known to mediate cellular stress signaling pathways through activating p38 kinase. We here observed that ectopically expression of ASK1, but not its kinase-dead mutant, impaired cell proliferation and migration in lung cancer A549 and NCI-H1975 cells. To our surprise, this inhibitory effect of ASK1 is independent on activation of p38 kinase. We further discovered that ASK1 interacts with the WW domain of YAP and TAZ (also WWTR1) that are transcriptional co-activators and the Hippo signaling effectors. Overexpression of wild type ASK1, but not the kinase-dead mutant, in the lung cancer cells down-regulated the expression of the YAP/TAZ target genes CYR61 and CTGF. It seems that ASK1 specifically inactivates TAZ, not YAP, as ASK1 blocked nuclear translocation of TAZ only, while had no effect on YAP. Furthermore, knockdown of TAZ in the lung cancer cells caused the same inhibitory effect on cell proliferation and migration as that of overexpression of ASK1. Thus, our studies have defined a new signaling pathway of ASK1 for regulation of lung cancer cell proliferation and migration via interacting with and inactivating TAZ.

CD34+KLF4+ Stromal Stem Cells Contribute to Endometrial Regeneration and Repair

The regenerative capacity of the human endometrium requires a population of local stem cells. However, the phenotypes, locations, and origin of these cells are still unknown. In a mouse menstruation model, uterine stromal SM22α⁺-derived CD34⁺KLF4⁺ stem cells are activated and integrate into the regeneration area, where they differentiate and incorporate into the endometrial epithelium; this process is correlated with enhanced protein SUMOylation in CD34⁺KLF4⁺ cells. Mice with a stromal SM22α-specific SENP1 deletion (SENP1smKO) exhibit accelerated endometrial repair in the regeneration model and develop spontaneous uterine hyperplasia. Mechanistic studies suggest that SENP1 deletion induces SUMOylation of ERα, which augments ERα transcriptional activity and proliferative signaling in SM22α⁺CD34⁺KLF4⁺ cells. These cells then transdifferentiate to the endometrial epithelium. Our study reveals that CD34⁺KLF4⁺ stromal-resident stem cells directly contribute to endometrial regeneration, which is regulated through SENP1-mediated ERα suppression.

The regenerative capacity of the human endometrium requires a population of local stem cells. Here, Yin et al. show that uterine stromal SM22α⁺CD34⁺KLF4⁺ stem cells are activated by ERα SUMOylation and integrate into the regeneration area, where they differentiate and incorporate into the endometrial epithelium.

Four genes predict the survival of osteosarcoma patients based on TARGET database

Osteosarcoma represents one of the most aggressive tumors of bone among adolescents and young adults. Despite improvements in treatment, osteosarcoma has a grave prognosis. The identification of prognostic factors is still in its infancy. Weighted gene correlation network analysis (WGCNA) was conducted on mRNA-sequencing and clinical information (gender, survival and metastasis) of osteosarcoma patients from the TARGET database to obtain genes in modules associated with metastasis of osteosarcoma. The Cox regression analysis was then performed on the gene expression profile from TARGET to screen genes associated with patients' survival. Known genes related to osteosarcoma were obtained by intersecting osteosarcoma-related genes from DisGeNET and DiGSeE, followed by the construction of PPI network of osteosarcoma-related genes and survival-related genes in modules. The screened key genes were subject to multi-factor Cox proportional hazards model, and osteosarcoma patients were classified into high- and low- risk groups according to the risk score to evaluate the potential of key genes to predict the survival of osteosarcoma patients. The WGCNA showed that 4 genes in tan and 19 genes in pink modules were related to the survival of osteosarcoma patients. Osteosarcoma-related known genes (9) were obtained in intersection of DisGeNET and DiGSeE. PPI network identified 4 key genes (KRT5, HIPK2, MAP3K5 and CD5) closely associated with survival of osteosarcoma patients. HIPK2, MAP3K5 and CD5 expression was inversely correlated with survival risk, while KRT5 expression was positively correlated with survival risk. These results show KRT5, HIPK2, MAP3K5 and CD5 serve as prognostic factors of osteosarcoma patients.

Current insights into the metastasis of epithelial ovarian cancer - hopes and hurdles

BACKGROUND

Ovarian cancer is the most lethal gynecologic cancer and the fifth leading cause of cancer-related mortality in women worldwide. Despite various attempts to improve the diagnosis and therapy of ovarian cancer patients, the survival rate for these patients is still dismal, mainly because most of them are diagnosed at a late stage. Up to 90% of ovarian cancers arise from neoplastic transformation of ovarian surface epithelial cells, and are usually referred to as epithelial ovarian cancer (EOC). Unlike most human cancers, which are disseminated through blood-borne metastatic routes, EOC has traditionally been thought to be disseminated through direct migration of ovarian tumor cells to the peritoneal cavity and omentum via peritoneal fluid. It has recently been shown, however, that EOC can also be disseminated through blood-borne metastatic routes, challenging previous thoughts about ovarian cancer metastasis.

CONCLUSIONS

Here, we review our current understanding of the most updated cellular and molecular mechanisms underlying EOC metastasis and discuss in more detail two main metastatic routes of EOC, i.e., transcoelomic metastasis and hematogenous metastasis. The emerging concept of blood-borne EOC metastasis has led to exploration of the significance of circulating tumor cells (CTCs) as novel and non-invasive prognostic markers in this daunting cancer. We also evaluate the role of tumor stroma, including cancer associated fibroblasts (CAFs), tumor associated macrophages (TAMs), endothelial cells, adipocytes, dendritic cells and extracellular matrix (ECM) components in EOC growth and metastasis. Lastly, we discuss therapeutic approaches for targeting EOC. Unraveling the mechanisms underlying EOC metastasis will open up avenues to the design of new therapeutic options. For instance, understanding the molecular mechanisms involved in the hematogenous metastasis of EOC, the biology of CTCs, and the detailed mechanisms through which EOC cells take advantage of stromal cells may help to find new opportunities for targeting EOC metastasis.

Discovery and development of ASK1 inhibitors

Aberrant activation of mitogen-activated protein kinases (MAPKs) like c-Jun N-terminal kinase (JNK) and p38 is an event involved in the pathophysiology of numerous human diseases. The apoptosis signal-regulating kinase 1 (ASK1) is an upstream target that gets activated only under pathological conditions and as such is a promising target for therapeutic intervention. In the first part of this review the molecular mechanisms leading to ASK1 activation and regulation will be described as well as the evidences supporting a pathogenic role for ASK1 in human disease. In the second part, an update on drug discovery efforts towards the discovery and development of ASK1-targeting therapies will be provided.

Potent BRD4 inhibitor suppresses cancer cell-macrophage interaction

Small molecule inhibitor of the bromodomain and extraterminal domain (BET) family proteins is a promising option for cancer treatment. However, current BET inhibitors are limited by their potency or oral bioavailability. Here we report the discovery and characterization of NHWD-870, a BET inhibitor that is more potent than three major clinical stage BET inhibitors BMS-986158, OTX-015, and GSK-525762. NHWD-870 causes tumor shrinkage or significantly suppresses tumor growth in nine xenograft or syngeneic models. In addition to its ability to downregulate c-MYC and directly inhibit tumor cell proliferation, NHWD-870 blocks the proliferation of tumor associated macrophages (TAMs) through multiple mechanisms, partly by reducing the expression and secretion of macrophage colony-stimulating factor CSF1 by tumor cells. NHWD-870 inhibits CSF1 expression through suppressing BRD4 and its target HIF1α. Taken together, these results reveal a mechanism by which BRD4 inhibition suppresses tumor growth, and support further development of NHWD-870 to treat solid tumors.

Inhibitors of the BET family proteins are limited by their potency and oral bio-availability. Here, the authors report a new BET inhibitor, NHWD-870, with improved potency compared to previous BET inhibitors, and show that it suppresses BRD4 and targets tumour associated macrophages.

Discovery of a 2-pyridinyl urea-containing compound YD57 as a potent inhibitor of apoptosis signal-regulating kinase 1 (ASK1)

Inhibition of MAP3K kinase ASK1 has been an attractive strategy for the treatment of nonalcoholic steatohepatitis and multiple sclerosis, among others. Herein, we reported the discovery of 2-pyridinyl urea-containing compound 14l (YD57) as a potent, small-molecule inhibitor of ASK1. 14l was selective against MAP3K kinases ASK2 and TAK1 (>140-fold), while it also inhibited several cell cycle regulating kinases with IC₅₀ values in a range of 90-400 nM (<20-fold selectivity). As a consequence, 14l had stronger apoptosis induction, more potent G1 cell cycle arrest activities, and lower IC₅₀ value of cell growth inhibition than that of GS4997 in HepG2 cancer cell line. On the other hand, 14l did not inhibit ASK1 and p38 phosphorylation in intact cells. We reason that the multi-target effects of 14l likely neutralized the activities caused by inhibition of cellular ASK1. Future studies of these ASK1 inhibitors should pay close attention to their kinome selectivity profile.

AIP1 Suppresses Transplant Arteriosclerosis Through Inhibition of Vascular Smooth Muscle Cell Inflammatory Response to IFNγ

IFNγ-induced vascular smooth muscle cells (VSMCs) inflammatory response plays a key role in transplant arteriosclerosis (TA). However, the mechanisms regulating this process remains poorly defined. Here, we show that ASK1-interacting protein 1 (AIP1) deletion markedly augments the expression of IFNγ-induced chemokines in mouse aortic allografts. Subsequently, donor arterial grafts from AIP1 deficient mice exhibited an accelerated development of TA. Furthermore, AIP1 knockdown significantly increased IFNγ signaling activation in cultured VSMCs and thus enhances chemokines production in response to IFNγ. Together, we conclude that AIP1 functions as an inhibitor of VSMCs inflammation by regulating IFNγ signaling and therefore suppresses TA progression. Our findings suggest that AIP1 might be a potential therapeutic target for chronic transplant rejection. Anat Rec, 302:1587-1593, 2019. © 2018 American Association for Anatomy.

SUMOylation of VEGFR2 regulates its intracellular trafficking and pathological angiogenesis

Regulation of VEGFR2 represents an important mechanism for the control of angiogenesis. VEGFR2 activity can be regulated by post-translational modifications such as ubiquitination and acetylation. However, whether VEGFR2 can be regulated by SUMOylation has not been investigated. Here we show that endothelial-specific deletion of the SUMO endopeptidase SENP1 reduces pathological angiogenesis and tissue repair during hindlimb ischemia, and VEGF-induced angiogenesis in the cornea, retina, and ear. SENP1-deficient endothelial cells show increased SUMOylation of VEGFR2 and impaired VEGFR2 signalling. SUMOylation at lysine 1270 retains VEGFR2 in the Golgi and reduces its surface expression, attenuating VEGFR2-dependent signalling. Moreover, we find that SENP1 is downregulated and VEGFR2 hyper-SUMOylated in diabetic settings and that expression of a non-SUMOylated form of VEGFR2 rescues angiogenic defects in diabetic mice. These results show that VEGFR2 is regulated by deSUMOylation during pathological angiogenesis, and propose SENP1 as a potential therapeutic target for the treatment of diabetes-associated angiogenesis.

ASK family in cardiovascular biology and medicine

Cardiovascular disease is a major cause of death worldwide. Mitogen-activated protein kinase (MAPK) signal cascades signaling pathways play crucial roles in cardiovascular pathophysiology. Apoptosis signal-regulating kinase (ASK) family members ASK1, ASK2 and ASK3 are the key molecules in MAPK signal cascades and are activated by various stresses. ASK1 is the most extensively studied MAPKKK and is involved in regulation of the cellular functions such as cell survival, proliferation, inflammation and apoptosis. The current review focuses on the relationship between ASK1 and cardiovascular disease, while exploring the novel therapeutic strategies for cardiovascular disease involved in the ASK1 signal pathway.