HB-EGF is a potent inducer of tumor growth and angiogenesis

CDK4/6 inhibitors induce breast cancer senescence with enhanced anti-tumor immunogenic properties compared with DNA-damaging agents

Since therapy-induced senescence (TIS) can either support or inhibit cancer progression, identifying which types of chemotherapeutic agents can produce the strongest anti-tumor TIS is an important issue. Here, cyclin-dependent kinase4/6 inhibitors (CDK4/6i)-induced senescence was compared to the TIS induced by conventional DNA-damaging agents. Despite both types of agents eliciting a similar degree of senescence, we observed increased expression of the senescence-associated secretory phenotype (SASP) and ligands related to pro-tumor immunity (IL6, CXCL8, TGFβ, CD274, and CEACAM1) and angiogenesis (VEGFA) mainly in TIS induced by DNA-damaging agents rather than by CDK4/6i. Additionally, although all agents increased the expression of anti-tumor immunomodulatory proteins related to antigen presentation (MHC-I, B2M) and T cell chemokines (CXCL9, 10, 11), CDK4/6i-induced senescent cells still maintained this expression at a similar or even higher intensity than cells treated with DNA-damaging agents, despite the absence of nuclear factor-kappa-B (NF-κB) and p53 activation. These data suggest that in contrast with DNA-damaging agents, which augment the pro-tumorigenic microenvironment via pro-inflammatory SASP, CDK4/6i can generate TIS only with antitumor immunomodulatory proteins.

A Unified Bayesian Framework for Bi-overlapping-Clustering Multi-omics Data via Sparse Matrix Factorization

The advances of modern sequencing techniques have generated an unprecedented amount of multi-omics data which provide great opportunities to quantitatively explore functional genomes from different but complementary perspectives. However, distinct modalities/sequencing technologies generate diverse types of data which greatly complicate statistical modeling because uniquely optimized methods are required for handling each type of data. In this paper, we propose a unified framework for Bayesian nonparametric matrix factorization that infers overlapping bi-clusters for multi-omics data. The proposed method adaptively discretizes different types of observations into common latent states on which cluster structures are built hierarchically. The proposed Bayesian nonparametric method is able to automatically determine the number of clusters. We demonstrate the utility of the proposed method using simulation studies and applications to a single-cell RNA-sequencing dataset, a combination of single-cell RNA-sequencing and single-cell ATAC-sequencing dataset, a bulk RNA-sequencing dataset, and a DNA methylation dataset which reveal several interesting findings that are consistent with biological literature.

Western Diet-induced Transcriptional Changes in Anastomotic Tissue Is Associated With Early Local Recurrence in a Mouse Model of Colorectal Surgery

OBJECTIVE

To determine the timeframe and associated changes in the microenvironment that promote the development of a diet-induced local-regional recurrence in a mouse model of colorectal surgery.

BACKGROUND

Postoperative recurrence and metastasis occur in up to 30% of patients undergoing attempted resection for colorectal cancer (CRC). The underlying mechanisms that drive the development of postoperative recurrences are poorly understood. Preclinical studies have demonstrated a diet and microbial-driven pathogenesis of local-regional recurrence, yet the precise mechanisms remain undefined.

METHODS

BALB/C mice were fed a western diet (WD) or standard diet (SD), underwent a colon resection and anastomosis, given an Enterococcus faecalis enema on postoperative day (POD) 1, and subjected to a CT26 cancer cell enema (mimicking shed cancer cells) on POD2. Mice were sacrificed between POD3 and POD7 and cancer cell migration was tracked. Dynamic changes in gene expression of anastomotic tissue that were associated with cancer cell migration was assessed.

RESULTS

Tumor cells were identified in mice fed either a SD or WD in both anastomotic and lymphatic tissue as early as on POD3. Histology demonstrated that these tumor cells were viable and replicating. In WD-fed mice, the number of tumor cells increased over the early perioperative period and was significantly higher than in mice fed a SD. Microarray analysis of anastomotic tissue found that WD-fed mice had 11 dysregulated genes associated with tumorigenesis.

CONCLUSIONS

A WD promotes cancer cells to permeate a healing anastomosis and migrate into anastomotic and lymphatic tissue forming viable tumor nodules. These data offer a novel recurrence pathogenesis by which the intestinal microenvironment promotes a CRC local-regional recurrence.

Endothelial Notch Signaling Regulates the Function of the Retinal Pigment Epithelial Barrier via EC Angiocrine Signaling

The outer blood-retina barrier (oBRB), comprises tightly connected retinal pigment epithelium (RPE) cells, Bruch's membrane, and choroid blood vessels, and is essential for retinal health and normal visual function. Disruption of the RPE barrier and its dysfunction can lead to retinal disorders such as age-related macular degeneration (AMD). In the present study, we investigated the essential role of choroid endothelial cells (ECs) in the RPE barrier formation process and its dysfunction. We discovered that ECs promoted RPE barrier formation through angiocrine signaling. Through blocking or activating endothelial Notch signaling and conducting experiments in vitro and in vivo, we confirmed that endothelial Notch signaling regulated the expression of heparin-binding epidermal growth factor (HBEGF) and consequently impacted the expression and activity of matrix metalloproteinases (MMP)-9 in RPE cells. This modulation influenced the RPE extracellular matrix deposition, tight junctions and RPE barrier function. In in vivo experiments, the intravitreal administration of recombinant HBEGF (r-HBEGF) alleviated the RPE barrier disruption induced by subretinal injection (SI) or laser treatment and also rescued RPE barrier disruption in endothelial Notch-deficient mice. Our results showed that the endothelial Notch signaling drove HBEGF expression through angiocrine signaling and effectively improved RPE barrier function by regulating the MMP-9 expression in RPE cells. It suggests that the modulation of Notch signaling in the choroidal endothelium may offer a novel therapeutic strategy for retinal degenerative diseases.

Single-cell RNA sequencing distinctly characterizes the wide heterogeneity in pediatric mixed phenotype acute leukemia

BACKGROUND

Mixed phenotype acute leukemia (MPAL), a rare subgroup of leukemia characterized by blast cells with myeloid and lymphoid lineage features, is difficult to diagnose and treat. A better characterization of MPAL is essential to understand the subtype heterogeneity and how it compares with acute myeloid leukemia (AML) and acute lymphoblastic leukemia (ALL). Therefore, we performed single-cell RNA sequencing (scRNAseq) on pediatric MPAL bone marrow (BM) samples to develop a granular map of the MPAL blasts and microenvironment landscape.

METHODS

We analyzed over 40,000 cells from nine pediatric MPAL BM samples to generate a single-cell transcriptomic landscape of B/myeloid (B/My) and T/myeloid (T/My) MPAL. Cells were clustered using unsupervised single-cell methods, and malignant blast and immune clusters were annotated. Differential expression analysis was performed to identify B/My and T/My MPAL blast-specific signatures by comparing transcriptome profiles of MPAL with normal BM, AML, and ALL. Gene set enrichment analysis (GSEA) was performed, and significantly enriched pathways were compared in MPAL subtypes.

RESULTS

B/My and T/My MPAL blasts displayed distinct blast signatures. Transcriptomic analysis revealed that B/My MPAL profile overlaps with B-ALL and AML samples. Similarly, T/My MPAL exhibited overlap with T-ALL and AML samples. Genes overexpressed in both MPAL subtypes' blast cells compared to AML, ALL, and healthy BM included MAP2K2 and CD81. Subtype-specific genes included HBEGF for B/My and PTEN for T/My. These marker sets segregated bulk RNA-seq AML, ALL, and MPAL samples based on expression profiles. Analysis comparing T/My MPAL to ETP, near-ETP, and non-ETP T-ALL, showed that T/My MPAL had greater overlap with ETP-ALL cases. Comparisons among MPAL subtypes between adult and pediatric samples showed analogous transcriptomic landscapes of corresponding subtypes. Transcriptomic differences were observed in the MPAL samples based on response to induction chemotherapy, including selective upregulation of the IL-16 pathway in relapsed samples.

CONCLUSIONS

We have for the first time described the single-cell transcriptomic landscape of pediatric MPAL and demonstrated that B/My and T/My MPAL have distinct scRNAseq profiles from each other, AML, and ALL. Differences in transcriptomic profiles were seen based on response to therapy, but larger studies will be needed to validate these findings.

Spinal cord repair is modulated by the neurogenic factor Hb-egf under direction of a regeneration-associated enhancer

Unlike adult mammals, zebrafish regenerate spinal cord tissue and recover locomotor ability after a paralyzing injury. Here, we find that ependymal cells in zebrafish spinal cords produce the neurogenic factor Hb-egfa upon transection injury. Animals with hb-egfa mutations display defective swim capacity, axon crossing, and tissue bridging after spinal cord transection, associated with disrupted indicators of neuron production. Local recombinant human HB-EGF delivery alters ependymal cell cycling and tissue bridging, enhancing functional regeneration. Epigenetic profiling reveals a tissue regeneration enhancer element (TREE) linked to hb-egfa that directs gene expression in spinal cord injuries. Systemically delivered recombinant AAVs containing this zebrafish TREE target gene expression to crush injuries of neonatal, but not adult, murine spinal cords. Moreover, enhancer-based HB-EGF delivery by AAV administration improves axon densities after crush injury in neonatal cords. Our results identify Hb-egf as a neurogenic factor necessary for innate spinal cord regeneration and suggest strategies to improve spinal cord repair in mammals.

An unanticipated discourse of HB-EGF with VANGL2 signaling during embryo implantation

Implantation is the first direct encounter between the embryo and uterus during pregnancy, and Hbegf is the earliest known molecular signaling for embryo-uterine crosstalk during implantation. The downstream effectors of heparin-binding EGF (HB-EGF) in implantation remain elusive due to the complexity of EGF receptor family. This study shows that the formation of implantation chamber (crypt) triggered by HB-EGF is disrupted by uterine deletion of Vangl2, a key planar cell polarity component (PCP). We found that HB-EGF binds to ERBB2 and ERBB3 to recruit VANGL2 for tyrosine phosphorylation. Using in vivo models, we show that uterine VAGL2 tyrosine phosphorylation is suppressed in Erbb2/Erbb3 double conditional knockout mice. In this context, severe implantation defects in these mice lend support to the critical role of HB-EGF-ERBB2/3-VANGL2 in establishing a two-way dialogue between the blastocyst and uterus. In addition, the result addresses an outstanding question how VANGL2 is activated during implantation. Taken together, these observations reveal that HB-EGF regulates the implantation process by influencing uterine epithelial cell polarity comprising VANGL2.

Chemokines network in bone metastasis: Vital regulators of seeding and soiling

Chemokines are well equipped with chemo-attractive signals that can regulate cancer cell trafficking to specific organ sites. Currently, updated concepts have revealed the diverse role of chemokines in the biology of cancer initiation and progression. Genomic instabilities and alterations drive tumor heterogeneity, providing more options for the selection and metastatic progression to cancer cells. Tumor heterogeneity and acquired drug resistance are the main obstacles in managing cancer therapy and the primary root cause of metastasis. Studies emphasize that multiple chemokine/receptor axis are involved in cancer cell-mediated organ-specific distant metastasis. One of the persuasive mechanisms for heterogeneity and subsequent events is sturdily interlinked with the crosstalk between chemokines and their receptors on cancer cells and tissue-specific microenvironment. Among different metastatic niches, skeletal metastasis is frequently observed in the late stages of prostate, breast, and lung cancer and significantly reduces the survival of cancer patients. Therefore, it is crucial to elucidate the role of chemokines and their receptors in metastasis and bone remodeling. Here, we review the potential chemokine/receptor axis in tumorigenesis, tumor heterogeneity, metastasis, and vicious cycle in bone microenvironment.

A Screening of Epigenetic Therapeutic Targets for Non-Small Cell Lung Cancer Reveals PADI4 and KDM6B as Promising Candidates

Despite advances in diagnostic and therapeutic approaches for lung cancer, new therapies targeting metastasis by the specific regulation of cancer genes are needed. In this study, we screened a small library of epigenetic inhibitors in non-small-cell lung cancer (NSCLC) cell lines and evaluated 38 epigenetic targets for their potential role in metastatic NSCLC. The potential candidates were ranked by a streamlined approach using in silico and in vitro experiments based on publicly available databases and evaluated by real-time qPCR target gene expression, cell viability and invasion assays, and transcriptomic analysis. The survival rate of patients with lung adenocarcinoma is inversely correlated with the gene expression of eight epigenetic targets, and a systematic review of the literature confirmed that four of them have already been identified as targets for the treatment of NSCLC. Using nontoxic doses of the remaining inhibitors, KDM6B and PADI4 were identified as potential targets affecting the invasion and migration of metastatic lung cancer cell lines. Transcriptomic analysis of KDM6B and PADI4 treated cells showed altered expression of important genes related to the metastatic process. In conclusion, we showed that KDM6B and PADI4 are promising targets for inhibiting the metastasis of lung adenocarcinoma cancer cells.

ADAM17-mediated EGFR ligand shedding directs macrophage promoted cancer cell invasion

Macrophages in the tumor microenvironment have a significant impact on tumor progression. Depending on the signaling environment in the tumor, macrophages can either support or constrain tumor progression. It is therefore of therapeutic interest to identify the tumor-derived factors that control macrophage education. With this aim, we correlated the expression of ADAM proteases, which are key mediators of cell-cell signaling, to the expression of pro-tumorigenic macrophage markers in human cancer cohorts. We identified ADAM17, a sheddase upregulated in many cancer types, as a protein of interest. Depletion of ADAM17 in cancer cell lines reduced the expression of several pro-tumorigenic markers in neighboring macrophages in vitro as well as in mouse models. Moreover, ADAM17-/- educated macrophages demonstrated a reduced ability to induce cancer cell invasion. Using mass spectrometry-based proteomics and ELISA, we identified HB-EGF and AREG, shed by ADAM17 in the cancer cells, as the implicated molecular mediators of macrophage education. Additionally, RNA-seq and ELISA experiments revealed that ADAM17-dependent HB-EGF-ligand release induces the expression and secretion of CXCL chemokines in macrophages, which in turn stimulates cancer cell invasion.In conclusion, we provide evidence that ADAM17 mediates a paracrine EGFR-ligand-chemokine feedback loop, whereby cancer cells hijack macrophages to promote tumor progression.

High Expression of the Lysosomal Protease Cathepsin D Confers Better Prognosis in Neuroblastoma Patients by Contrasting EGF-Induced Neuroblastoma Cell Growth

Neuroblastoma is a malignant extracranial solid tumor arising from the sympathoadrenal lineage of the neural crest and is often associated with N-MYC amplification. Cathepsin D has been associated with chemoresistance in N-MYC-overexpressing neuroblastomas. Increased EGFR expression also has been associated with the aggressive behavior of neuroblastomas. This work aimed to understand the mechanisms linking EGFR stimulation and cathepsin D expression with neuroblastoma progression and prognosis. Gene correlation analysis in pediatric neuroblastoma patients revealed that individuals bearing a high EGFR transcript level have a good prognosis only when CTSD (the gene coding for the lysosomal protease Cathepsin D, CD) is highly expressed. Low CTSD expression was associated with poor clinical outcome. CTSD expression was negatively correlated with CCNB2, CCNA2, CDK1 and CDK6 genes involved in cell cycle division. We investigated the biochemical pathways downstream to EGFR stimulation in human SH-SY5Y neuroblastoma cells engineered for overexpressing or silencing of CD expression. Cathepsin D overexpression decreased the proliferative potential of neuroblastoma cells through downregulation of the pro-oncogenic MAPK signaling pathway. EGFR stimulation downregulated cathepsin D expression, thus favoring cell cycle division. Our data suggest that chemotherapeutics that inhibit the EGFR pathway, along with stimulators of cathepsin D synthesis and activity, could benefit neuroblastoma prognosis.

Fundamentals of bone vasculature: Specialization, interactions and functions

Angiogenesis, hematopoiesis and osteogenesis are fundamental processes mediating complex and essential biological functions. In the bone marrow, endothelial cells (ECs) are a principal mediator of regulatory signals that govern hematopoietic and mesenchymal stem cells. EC and osteoblast interactions and niche functions of ECs are fundamental in maintaining bone health and coordinating repair and regeneration following injury. These cellular interactions are subject to dysregulation and deterioration under stress, aging, chronic disease states and malignancy. Thus, the prospect of manipulating the bone vasculature has tremendous potential to advance therapeutic interventions for the management of bone diseases. This review discusses the current state of vascular-skeletal tissue interactions focusing on osteoblast and hematopoietic stem cells interaction with ECs.

Group 3 innate lymphoid cells produce the growth factor HB-EGF to protect the intestine from TNF-mediated inflammation

Tumor necrosis factor (TNF) drives chronic inflammation and cell death in the intestine, and blocking TNF is a therapeutic approach in inflammatory bowel disease (IBD). Despite this knowledge, the pathways that protect the intestine from TNF are incompletely understood. Here we demonstrate that group 3 innate lymphoid cells (ILC3s) protect the intestinal epithelium from TNF-induced cell death. This occurs independent of interleukin-22 (IL-22), and we identify that ILC3s are a dominant source of heparin-binding epidermal growth factor-like growth factor (HB-EGF). ILC3s produce HB-EGF in response to prostaglandin E2 (PGE2) and engagement of the EP2 receptor. Mice lacking ILC3-derived HB-EGF exhibit increased susceptibility to TNF-mediated epithelial cell death and experimental intestinal inflammation. Finally, human ILC3s produce HB-EGF and are reduced from the inflamed intestine. These results define an essential role for ILC3-derived HB-EGF in protecting the intestine from TNF and indicate that disruption of this pathway contributes to IBD.

Immune Signature-Based Risk Stratification and Prediction of Immunotherapy Efficacy for Bladder Urothelial Carcinoma

Immune-related genes (IRGs) are closely related to tumor progression and the immune microenvironment. Few studies have investigated the effect of tumor immune microenvironment on the survival and response to immune checkpoint inhibitors of patients with bladder urothelial carcinoma (BLCA). We constructed two IRG-related prognostic signatures based on gene–immune interaction for predicting risk stratification and immunotherapeutic responses. We also verified their predictive ability on internal and overall data sets. Patients with BLCA were divided into high- and low-risk groups. The high-risk group had poor survival, enriched innate immune-related cell subtypes, low tumor mutation burden, and poor response to anti-PD-L1 therapy. Our prognostic signatures can be used as reliable prognostic biomarkers, which may be helpful to screen the people who will benefit from immunotherapy and guide the clinical decision-making of patients with BLCA.

Zinc finger protein 852 is essential for the proliferation, drug sensitivity, and self-renewal of gastric cancer cells

Exploring cellular and molecular mechanisms responsible for gastric cancer growth, survival, self-renewal, and metastasis helps develop efficacious therapeutic strategies. In this study, the expression and function of Zinc finger protein 852 (ZNF852) in human gastric cancer cell lines were characterized. ZNF852 was up-regulated in gastric cancer cell lines relative to normal gastric epithelial cell line GES-1. When the ZNF852 gene was ablated in gastric cancer cell line MGC-803 using the CRISPR/Cas9-encoding lentivirus, the proliferation of MGC-803 was suppressed. ZNF852 deficiency also resulted in the inhibition of MGC-803 sphere formation, along with decreases in SRY-box 2 (SOX2), Octamer-binding transcription factor 4 (OCT4), and Nanog homeobox (NANOG), suggesting that ZNF852 sustains self-renewal of MGC-803 cells. Furthermore, ZNF852 deficiency increased oxaliplatin-induced MGC-803 cell death, implying the role of ZNF852 in drug sensitivity. Subcutaneous infusion of MGC-803 cells into nude mice illustrated the same effects of ZNF852 on the proliferation and self-renewal of gastric cancer cells. Similar effects of ANF852 were also seen in gastric cancer cell line SNU-1. Interestingly, ZNF852 deficiency caused down-regulation of epidermal growth factor receptor (EGFR) on gastric cancer cells. In summary, this study uncovers the positive regulatory role of ZNF852 in gastric cancer growth and maintenance. ZNF852 could be a potential therapeutic target for inhibiting gastric cancer initiation or progression. This article is protected by copyright. All rights reserved.

ELTD1 Activation Induces an Endothelial-EMT Transition to a Myofibroblast Phenotype

ELTD1 is expressed in endothelial and vascular smooth muscle cells and has a role in angiogenesis. It has been classified as an adhesion GPCR, but as yet, no ligand has been identified and its function remains unknown. To establish its role, ELTD1 was overexpressed in endothelial cells. Expression and consequently ligand independent activation of ELTD1 results in endothelial-mesenchymal transistion (EndMT) with a loss of cell-cell contact, formation of stress fibres and mature focal adhesions and an increased expression of smooth muscle actin. The effect was pro-angiogenic, increasing Matrigel network formation and endothelial sprouting. RNA-Seq analysis after the cells had undergone EndMT revealed large increases in chemokines and cytokines involved in regulating immune response. Gene set enrichment analysis of the data identified a number of pathways involved in myofibroblast biology suggesting that the endothelial cells had undergone a type II EMT. This type of EMT is involved in wound repair and is closely associated with inflammation implicating ELTD1 in these processes.

Fucoxanthin Exerts Anti-Tumor Activity on Canine Mammary Tumor Cells via Tumor Cell Apoptosis Induction and Angiogenesis Inhibition

Fucoxanthin is a carotenoid derived from brown algae. It is known to exhibit anticancer activity, including the promotion of apoptosis and cell cycle arrest in several tumors. However, it remains unclear whether fucoxanthin exhibits anticancer activity against mammary gland tumors. In this study, we evaluated fucoxanthin activity against canine mammary tumor cells (CMT-U27) and human umbilical vein endothelial cells (HUVECs) to investigate its effect on cell viability, migration, tube formation, and angiopoietin 2 (Ang2) expression. Our results showed that fucoxanthin induced apoptosis via caspase activation in CMT-U27 cells. In rat aortic ring assay, fucoxanthin suppressed endothelial cell sprouting. Furthermore, fucoxanthin inhibited tube formation and migration in HUVECs. The number of migrated cells was assessed using CMT-U27 cells. The results demonstrated that fucoxanthin exerted anti-angiogenic activity on HUVECs and CMT-U27 cells by promoting Ang2 expression. In conclusion, our results demonstrated that fucoxanthin induced tumor cell death and inhibited angiogenesis, suggesting that fucoxanthin could be considered as a promising therapeutic agent for canine mammary gland tumors.

PIP2 corrects cerebral blood flow deficits in small vessel disease by rescuing capillary Kir2.1 activity

Cerebral small vessel diseases (SVDs) are a central link between stroke and dementia-two comorbidities without specific treatments. Despite the emerging consensus that SVDs are initiated in the endothelium, the early mechanisms remain largely unknown. Deficits in on-demand delivery of blood to active brain regions (functional hyperemia) are early manifestations of the underlying pathogenesis. The capillary endothelial cell strong inward-rectifier K⁺ channel Kir2.1, which senses neuronal activity and initiates a propagating electrical signal that dilates upstream arterioles, is a cornerstone of functional hyperemia. Here, using a genetic SVD mouse model, we show that impaired functional hyperemia is caused by diminished Kir2.1 channel activity. We link Kir2.1 deactivation to depletion of phosphatidylinositol 4,5-bisphosphate (PIP₂), a membrane phospholipid essential for Kir2.1 activity. Systemic injection of soluble PIP₂ rapidly restored functional hyperemia in SVD mice, suggesting a possible strategy for rescuing functional hyperemia in brain disorders in which blood flow is disturbed.

The cerebral microvasculature: Basic and clinical perspectives on stroke and glioma

Microvascular networks are vital components of the cardiovascular system, performing many key roles in maintaining the health and homeostasis of the tissues and organs in which they develop. As discussed in this review, the molecular and cellular components within the microcirculation orchestrate critical processes to establish functional capillary beds, including organization of endothelial cell (EC) polarity, guiding investment of vascular pericytes (PCs), and building the specialized extracellular matrix (ECM) that comprises the vascular basement membrane (vBM). Herein, we further discuss the unique features of the microvasculature in the central nervous system (CNS), focusing on the cells contributing to the neurovascular unit (NVU) that form and maintain the blood-brain barrier (BBB). With a focus on vascular PCs, we offer basic and clinical perspectives on neurovascular-related pathologies that involve defects within the cerebral microvasculature. Specifically, we present microvascular anomalies associated with glioblastoma multiforme (GBM) including defects in vascular-immune cell interactions and associated clinical therapies targeting microvessels (ie, vascular-disrupting/anti-angiogenic agents and focused ultrasound). We also discuss the involvement of the microcirculation in stroke responses and potential therapeutic approaches. Our goal was to compare the cellular and molecular changes that occur in the microvasculature and NVU, and to provide a commentary on factors driving disease progression in GBM and stroke. We conclude with a forward-looking perspective on the importance of microcirculation research in developing clinical treatments for these devastating conditions.

HB-EGF-EGFR Signaling in Bone Marrow Endothelial Cells Mediates Angiogenesis Associated with Multiple Myeloma

Epidermal growth factor receptor (EGFR) and its ligand heparin-binding EGF-like growth factor (HB-EGF) sustain endothelial cell proliferation and angiogenesis in solid tumors, but little is known about the role of HB-EGF–EGFR signaling in bone marrow angiogenesis and multiple myeloma (MM) progression. We found that bone marrow endothelial cells from patients with MM express high levels of EGFR and HB-EGF, compared with cells from patients with monoclonal gammopathy of undetermined significance, and that overexpressed HB-EGF stimulates EGFR expression in an autocrine loop. We also found that levels of EGFR and HB-EGF parallel MM plasma cell number, and that HB-EGF is a potent inducer of angiogenesis in vitro and in vivo. Moreover, blockade of HB-EGF–EGFR signaling, by an anti-HB-EGF neutralizing antibody or the EGFR inhibitor erlotinib, limited the angiogenic potential of bone marrow endothelial cells and hampered tumor growth in an MM xenograft mouse model. These results identify HB-EGF–EGFR signaling as a potential target of anti-angiogenic therapy, and encourage the clinical investigation of EGFR inhibitors in combination with conventional cytotoxic drugs as a new therapeutic strategy for MM.

Neural JNK3 regulates blood flow recovery after hindlimb ischemia in mice via an Egr1/Creb1 axis

Diseases related to impaired blood flow such as peripheral artery disease (PAD) impact nearly 10 million people in the United States alone, yet patients with clinical manifestations of PAD (e.g., claudication and limb ischemia) have limited treatment options. In ischemic tissues, stress kinases such as c-Jun N-terminal kinases (JNKs), are activated. Here, we show that inhibition of the JNK3 (Mapk10) in the neural compartment strikingly potentiates blood flow recovery from mouse hindlimb ischemia. JNK3 deficiency leads to upregulation of growth factors such as Vegfa, Pdgfb, Pgf, Hbegf and Tgfb3 in ischemic muscle by activation of the transcription factors Egr1/Creb1. JNK3 acts through Forkhead box O3 (Foxo3a) to suppress the activity of Egr1/Creb1 transcription regulators in vitro. In JNK3-deficient cells, Foxo3a is suppressed which leads to Egr1/Creb1 activation and upregulation of downstream growth factors. Collectively, these data suggest that the JNK3-Foxo3a-Egr1/Creb1 axis coordinates the vascular remodeling response in peripheral ischemia.

Stress kinases are activated in peripheral ischemic tissues in the presence of vascular diseases. Here the authors show that inhibition of the neural JNK3 kinase improves recovery from hind limb ischemia in animals through activation of the transcription factors Egr1/Creb1 and upregulation of growth factors.

Peptides derived from a short stretch of diphtheria toxin bind to heparin-binding epidermal growth factor-like growth factor

Membrane-anchored heparin-binding EGF-like growth factor (HB-EGF) is the receptor for diphtheria toxin (DT). Mutated or truncated, non-toxic DT has been used earlier for HB-EGF-targeted drug delivery and to modulate HB-EGF signaling. In the present work, we have synthesized a peptide corresponding to a 26 amino acid long stretch of the receptor-binding domain of DT. This region of DT makes multiple contacts with HB-EGF and has residues critical for binding to HB-EGF. We show that this peptide and two of its mutants bind to HB-EGF. We have also created recombinant proteins by fusing Maltose-binding Protein (MBP) with these peptides. These recombinant MBP-tagged peptides bind to HB-EGF with affinities in the range of 10^-7 to 10^-8 M. We have observed that these MBP-tagged peptides can modulate molecular signaling of HB-EGF. Therefore, this 26 amino acid long stretch of DT can be considered as an independent functional segment for binding to HB-EGF. Peptides corresponding to this region may be used for HB-EGF targeted cellular delivery of molecular cargo or to modulate HB-EGF signaling.

Reconnaissance of the candidate genes involved in the pathogenesis of human immunodeficiency virus and targeted by antiretroviral therapy

The expression levels of many genes change after treatment of human immunodeficiency virus (HIV)-infected subjects by antiretroviral drugs. High-throughput analysis of tremendous datasets led to the discovery of genes that are implicated in the treatment pathways. In this study, we performed a gene-enrichment analysis after determining the differentially expressed genes (DEGs) between untreated HIV-positive and HIV-negative subjects and also between treated HIV-positive subjects with antiretroviral therapy (ART; who receiving nucleoside reverse transcriptase inhibitor-based ART) and untreated HIV-positive cases in the peripheral blood mononuclear cells (PBMCs), adipose, and muscle tissues. In sum, the genes that activate inflammatory, immune response, proliferation, metabolism, and viral involvement pathways have different expression patterns in the untreated HIV-positive subjects and treated HIV-positive cases. Moreover, the expression levels of the genes including ACLY, ALDH18A1, HADHA, and YARS in the PBMCs tissue and HBEGF, PKN3, DEGS2, and EDN3 in the fat tissue were found to be different in the HIV-infected patients, which can be considered as new biomarkers for HIV infection.

Soluble Heparin Binding Epidermal Growth Factor-Like Growth Factor Is a Regulator of GALGT2 Expression and GALGT2-Dependent Muscle and Neuromuscular Phenotypes

GALGT2 (also B4GALNT2) encodes a glycosyltransferase that is normally confined to the neuromuscular and myotendinous junction in adult skeletal muscle. GALGT2 overexpression in muscle can inhibit muscular dystrophy in mouse models of the disease by inducing the overexpression of surrogate muscle proteins, including utrophin, agrin, laminins, and integrins. Despite its well-documented biological properties, little is known about the endogenous regulation of muscle GALGT2 expression. Here, we demonstrate that epidermal growth factor receptor (EGFR) ligands can activate the human GALGT2 promoter. Overexpression of one such ligand, soluble heparin-binding EGF-like growth factor (sHB-EGF), also stimulated mouse muscle Galgt2 gene expression and expression of GALGT2-inducible surrogate muscle genes. Deletion analysis of the GALGT2 promoter identified a 45-bp region containing a TFAP4-binding site that was required for sHB-EGF activation. sHB-EGF increased TFAP4 binding to this site in muscle cells and increased endogenous Tfap4 gene expression. sHB-EGF also increased muscle EGFR protein expression and activated EGFR-Akt signaling. sHB-EGF expression was concentrated at the neuromuscular junction, and Hbegf deletion reduced Galgt2-dependent synaptic glycosylation. Hbegf deletion also mimicked Galgt2-dependent neuromuscular and muscular dystrophy phenotypes. These data demonstrate that sHB-EGF is an endogenous regulator of muscle Galgt2 gene expression and can mimic Galgt2-dependent muscle phenotypes.

A First-in-Human Phase I Study of GC1118, a Novel Anti-Epidermal Growth Factor Receptor Antibody, in Patients with Advanced Solid Tumors

LESSONS LEARNED

GC1118 is a novel fully human anti-epidermal growth factor receptor (EGFR) antibody with unique binding epitopes and different ligand-binding inhibitory activity compared with cetuximab or panitumumab.GC1118 showed promising antitumor activity, especially in patients with colorectal cancer resistant to prior EGFR antibody. Skin toxicities were more common and diarrhea was less frequent compared with other anti-EGFR antibodies.

BACKGROUND

GC1118 is a novel monoclonal antibody targeting epidermal growth factor receptor (EGFR) with more potent ligand inhibition than cetuximab or panitumumab. We conducted a first-in-human, phase I study of GC118 in patients with refractory solid tumors.

METHODS

In the dose escalation part, GC1118 was administered on days 1, 8, 15, and 22, followed by a 2-week rest, during which dose-limiting toxicities (DLTs) were evaluated. In the expansion part, patients were enrolled into three cohorts (Cohort 1 [C1], patients with colorectal cancer [CRC] without prior anti-EGFR treatment; Cohort 2 [C2], patients with CRC with tumors resistant to anti-EGFR therapy; Cohort 3 [C3], EGFR-overexpressing gastric cancer).

RESULTS

In the dose escalation part, 24 patients were treated at five dose levels: 0.3, 1.0, 3.0, 4.0, and 5.0 mg/kg. In the 5.0 mg/kg cohort, two patients experienced DLTs (skin toxicities). The maximum-tolerated dose (MTD) was 4.0 mg/kg. Common adverse events were skin toxicities. In the expansion part, 39 patients were enrolled. In Cohort 1, stable disease (SD) was observed in 58%; in Cohort 2, partial response (PR) 17% and SD 8%; in Cohort 3, PR 8% and SD 17%.

CONCLUSION

GC1118 showed promising antitumor activity and was well tolerated. Infrequent diarrhea compared with other anti-EGFR antibodies might be advantageous for further development.

High-Fat Meal–Induced Changes in Markers of Inflammation and Angiogenesis in Healthy Adults Who Differ by Age and Physical Activity Level

Background

Inflammation and angiogenesis are key facets of cardiovascular disease pathophysiology. Age and physical activity level can influence fasting systemic inflammation, but the impact of these factors on postprandial inflammation is unknown. In addition, markers of angiogenesis have never been tested in the context of a single high-fat meal (HFM).

Objective

The purpose of this study was to investigate the effects of an HFM on markers of inflammation and angiogenesis in individuals of different ages and physical activity levels.

Methods

Twenty-two healthy adults—8 younger active (YA) adults (4 men, 4 women; mean ± SD age: 25 ± 5 y), 8 older active (OA) adults (4 men, 4 women; 67 ± 5 y), and 6 older inactive (OI) adults (3 men, 3 women; 68 ± 7 y)—consumed an HFM [63% fat (39% saturated fat, 14% monounsaturated fat, 10% polyunsaturated fat), 34% carbohydrate; 12 kcal/kg body mass; 927 ± 154 kcal]. Fourteen inflammatory and 9 angiogenic markers were measured at baseline and 3 and 6 h postmeal.

Results

Significant group effects were observed in interleukin (IL)-10 (YA > OA; P = 0.02), IL-23 (YA > OA; P = 0.02), tumor necrosis factor (TNF)-α (OA < OI; P = 0.04), and vascular endothelial growth factor (VEGF)-C (YA < OA; P = 0.001). IL-8, VEGF-A, VEGF-C, and heparin-binding epidermal growth factor–like growth factor significantly increased, whereas granulocyte-macrophage colony-stimulating factor, interferon-γ, IL-1β, IL-5, IL-10, IL-12, IL-13, IL-17A, IL-23, TNF-α, leptin, angiopoietin-2, and follistatin significantly decreased after HFM consumption (P’s < 0.05). Notably, VEGF-A and VEGF-C were significantly higher at 3 h [mean difference: 22.5 pg/mL (VEGF-A); 73.5 pg/mL (VEGF-C)] and 6 h postmeal [mean difference: 26.9 pg/mL (VEGF-A); 81.2 pg/mL (VEGF-C)].

Conclusions

A novel finding of this study was the robust increase in VEGF after an HFM. There were also group differences in several inflammatory markers (IL-10 and IL-23 greater in YA than OA, and TNF-α lower in OA than OI) that suggest a potential influence of age and physical activity level.

First-in-human study of the anti-HB-EGF antibody U3-1565 in subjects with advanced solid tumors

U3-1565 is a monoclonal antibody directed against heparin-binding epidermal growth factor-like growth factor (HB-EGF), which mediates angiogenesis via induction of vascular endothelial growth factor (VEGF-A). This first-in-human study characterized the safety, tolerability, efficacy, pharmacokinetics, and pharmacodynamics of U3-1565 in subjects with advanced solid tumors. In Part 1 (dose escalation following a modified 3 + 3 design), Cohorts 1-4, U3-1565 was administered at 2, 8, 16, and 24 mg/kg every 3 weeks for Cycle 1 and every 2 weeks thereafter. In Part 1, Cohort 5, and in Part 2 (dose expansion), U3-1565 was administered at 24 mg/kg every week. Thirty-six subjects were enrolled and treated (15 in Part 1; 21 in Part 2). No subject experienced dose limiting toxicity and maximum tolerated dose was not reached. All drug-related events were Grade 1 or 2 in severity, with fatigue and rash predominating. Following treatment with U3-1565, 1 subject with metastatic colorectal cancer experienced partial response and 6 subjects achieved stable disease. Four subjects completed the study main phase (first 12 cycles) and entered the extension phase. Of the 6/36 subjects with high (> 1500 pg/ml) baseline VEGF-A levels, all showed a decrease in VEGF-A (median - 60% [-22% to -97%]). Of the remaining subjects, only 19/30 showed a decrease (median - 18% [-2% to -82%]). Subjects with high VEGF-A baseline levels remained on treatment longer (3/6 entered study extension phase versus 1/30), and were more likely to show disease control (3/6 versus 4/30). In conclusion, U3-1565 demonstrates both proof of mechanism and clinical activity across different tumor types.

The somite-secreted factor Maeg promotes zebrafish embryonic angiogenesis

MAM and EGF containing gene (MAEG), also called Epidermal Growth Factor-like domain multiple 6 (EGFL6), belongs to the epidermal growth factor repeat superfamily. The role of Maeg in zebrafish angiogenesis remains unclear. It was demonstrated that maeg was dynamically expressed in zebrafish developing somite during a time window encompassing many key steps in embryonic angiogenesis. Maeg loss-of-function embryos showed reduced endothelial cell number and filopodia extensions of intersegmental vessels (ISVs). Maeg gain-of-function induced ectopic sprouting evolving into a hyperbranched and functional perfused vasculature. Mechanistically we demonstrate that Maeg promotes angiogenesis dependent on RGD domain and stimulates activation of Akt and Erk signaling in vivo. Loss of Maeg or Itgb1, augmented expression of Notch receptors, and inhibiting Notch signaling or Dll4 partially rescued angiogenic phenotypes suggesting that Notch acts downstream of Itgb1. We conclude that Maeg acts as a positive regulator of angiogenic cell behavior and formation of functional vessels.

ADAM9 promotes lung cancer progression through vascular remodeling by VEGFA, ANGPT2, and PLAT

Lung cancer has a very high prevalence of brain metastasis, which results in a poor clinical outcome. Up-regulation of a disintegrin and metalloproteinase 9 (ADAM9) in lung cancer cells is correlated with metastasis to the brain. However, the molecular mechanism underlying this correlation remains to be elucidated. Since angiogenesis is an essential step for brain metastasis, microarray experiments were used to explore ADAM9-regulated genes that function in vascular remodeling. The results showed that the expression levels of vascular endothelial growth factor A (VEGFA), angiopoietin-2 (ANGPT2), and tissue plasminogen activator (PLAT) were suppressed in ADAM9-silenced cells, which in turn leads to decreases in angiogenesis, vascular remodeling, and tumor growth in vivo. Furthermore, simultaneous high expression of ADAM9 and VEGFA or of ADAM9 and ANGPT2 was correlated with poor prognosis in a clinical dataset. These findings suggest that ADAM9 promotes tumorigenesis through vascular remodeling, particularly by increasing the function of VEGFA, ANGPT2, and PLAT.

Phase 1 Study of Monotherapy with KHK2866, an Anti-Heparin-Binding Epidermal Growth Factor-Like Growth Factor Monoclonal Antibody, in Patients with Advanced Cancer

BACKGROUND

KHK2866 is a recombinant, humanized, non-fucosylated, monoclonal antibody directed at heparin-binding epidermal growth factor-like growth factor (HB-EGF).

OBJECTIVE

To determine the safety, tolerability, maximum tolerated dose (MTD), pharmacokinetics, pharmacodynamics, potential immunogenicity, and preliminary clinical efficacy of KHK2866 monotherapy in patients with advanced and refractory cancer in a first-in-human, phase 1 study.

MATERIALS AND METHODS

Using a standard 3 + 3 dose-escalation design, 20 patients received KHK2866 (0.3, 1, and 3 mg/kg) intravenously once weekly. Two additional patients received 0.1 mg/kg in a cohort which was subsequently added following protocol amendment.

RESULTS

The first three patients enrolled experienced grade 2 hypersensitivity (acute infusion reactions) after the first dose of KHK2866. After prophylactic treatment with an H1-blocker and corticosteroids in subsequently recruited patients, two grade 2 hypersensitivity reactions were observed in the remaining 19 patients. Grade 2/3 neurotoxicity appeared to be dose-limiting at 3 mg/kg in the original dose-escalation cohorts (n = 2), at 1 mg/kg in the MTD dose expansion cohort (n = 1), and at 0.1 mg/kg (n = 1). Neurotoxicity was manifested as complex partial seizure activity, aphasia, and confusion after first-dose administration. Pharmacokinetic exposure to KHK2866 increased proportionally to dose. Mean elimination half-life was 71.9-118 h over the dose range from 0.3 to 3 mg/kg. All KHK2866 doses decreased serum free HB-EGF levels, generally below the lower limit of quantification.

CONCLUSIONS

The study was terminated because of neuropsychiatric toxicity. The only predictive factor for neuropsychiatric toxicity was administration of KHK2866. These effects were reversible, but were not predictable. Their etiology is not presently understood. [Study registered at ClinicalTrials.gov #NCT0179291].

Transcriptome analysis of mRNA and microRNAs in intramuscular fat tissues of castrated and intact male Chinese Qinchuan cattle

Intramuscular fat (IMF) is known to enhance beef palatability and can be markedly increased by castration. However, there is little understanding of the molecular mechanism underlying the IMF deposition after castration of beef cattle. We hypothesize that genetic regulators function differently in IMF from bulls and steers. Therefore, after detecting serum testosterone and lipid parameter, as well as the contents of IMF at 6, 12, 18 and 24 months, we have investigated differentially expressed (DE) microRNAs (miRNAs) and mRNAs in IMF of bulls and steers at 24 months of age in Qinchuan cattle using next-generation sequencing, and then explored the possible biopathways regulating IMF deposition. Serum testosterone levels were significantly decreased in steers, whereas IMF content, serum total cholesterol (TC), low-density lipoprotein cholesterol (LDL-C) and triglycerides (TGs) were markedly increased in steers. Comparing the results of steers and bulls, 580 upregulated genes and 1,120 downregulated genes in IMF tissues were identified as DE genes correlated with IMF deposition. The upregulated genes were mainly associated with lipid metabolism, lipogenesis and fatty acid transportation signalling pathways, and the downregulated genes were correlated with immune response and intracellular signal transduction. Concurrently, the DE miRNAs—important players in adipose tissue accumulation induced by castration—were also examined in IMF tissues; 52 DE miRNAs were identified. The expression profiles of selected genes and miRNAs were also confirmed by quantitative real-time PCR (qRT-PCR) assays. Using integrated analysis, we constructed the microRNA-target regulatory network which was supported by target validation using the dual luciferase reporter system. Moreover, Ingenuity Pathway Analysis (IPA) software was used to construct a molecular interaction network that could be involved in regulating IMF after castration. The detected molecular network is closely associated with lipid metabolism and adipocyte differentiation, which is supported by functional identification results of bta-let-7i on bovine preadipocytes. These results provided valuable insights into the molecular mechanisms of the IMF phenotype differences between steers and bulls.

Tumor p38MAPK signaling enhances breast carcinoma vascularization and growth by promoting expression and deposition of pro-tumorigenic factors

The breast carcinoma microenvironment strikingly influences cancer progression and response to therapy. Various cell types in the carcinoma microenvironment show significant activity of p38 mitogen-activated protein kinase (MAPK), although the role of p38MAPK in breast cancer progression is still poorly understood. The present study examined the contribution of tumor p38MAPK to breast carcinoma microenvironment and metastatic capacity. Inactivation of p38MAPK signaling in metastatic breast carcinoma cells was achieved by forced expression of the kinase-inactive mutant of p38/MAPK14 (a dominant-negative p38, dn-p38). Disruption of tumor p38MAPK signaling reduced growth and metastases of breast carcinoma xenografts. Importantly, dn-p38 markedly decreased tumor blood-vessel density and lumen sizes. Mechanistic studies revealed that p38 controls expression of pro-angiogenic extracellular factors such as matrix protein Fibronectin and cytokines VEGFA, IL8, and HBEGF. Tumor-associated fibroblasts enhanced tumor growth and vasculature as well as increased expression of the pro-angiogenic factors. These effects were blunted by dn-p38. Metadata analysis showed elevated expression of p38 target genes in breast cancers and this was an unfavorable marker of disease recurrence and poor-outcome. Thus, our study demonstrates that tumor p38MAPK signaling promotes breast carcinoma growth, invasive and metastatic capacities. Importantly, p38 enhances carcinoma vascularization by facilitating expression and deposition of pro-angiogenic factors. These results argue that p38MAPK is a valuable target for anticancer therapy affecting tumor vasculature. Anti-p38 drugs may provide new therapeutic strategies against breast cancer, including metastatic disease.

Hepatic cyclooxygenase-2 overexpression induced spontaneous hepatocellular carcinoma formation in mice

Cyclooxygenase (COX)-2 is upregulated in hepatocellular carcinoma (HCC). However, the direct causative effect of COX-2 in spontaneous HCC formation remains unknown. We thus investigate the role and molecular pathogenesis of COX-2 in HCC by using liver-specific COX-2 transgenic (TG) mice. We found spontaneous HCC formation with elevated inflammatory infiltrates and neovessels in male TG mice (3/21, 14.3%), but not in any of male WT mice (0/19). Reduced representation bisulfite sequencing (RRBS) and gene expression microarrays were performed in the HCC tumor and non-HCC liver tissues to investigate the molecular mechanisms of COX-2-driven HCC. By RRBS, DNA promoter hypermethylation was identified in HCC from TG mice. Induction of promoter hypermethylation was associated with reduced tet methylcytosine dioxygenase 1 (TET1) expression by COX-2. TET1 could catalyze the conversion of 5-methylcytosine into 5-hydroxymethylcytosine (5hmC) and prevents DNA hypermethylation. In keeping with this, loss of 5hmC was demonstrated in COX-2-induced HCC. Consistently, COX-2 overexpression in human HCC cell lines could reduce both TET1 expression and 5hmc levels. Integrative analyses of DNA methylation and gene expression profiles further identified significantly downregulated genes including LTBP1, ADCY5 and PRKCZ by promoter methylation in COX-2-induced HCC. Reduced expression of LTBP1, ADCY5 and PRKCZ by promoter hypermethylation was further validated in human HCCs. Bio-functional investigation revealed that LTBP1 inhibited cell proliferation in HCC cell lines, suggesting its potential role as a tumor suppressor in HCC. Gene expression microarrays revealed that signaling cascades (AKT (protein kinase B), STK33 (Serine/Threonine kinase 33) and MTOR (mechanistic target of rapamycin) pathways) were enriched in COX-2-induced HCC. In conclusion, this study demonstrated for the first time that enhanced COX-2 expression in hepatocytes is sufficient to induce HCC through inducing promoter hypermethylation by reducing TET1, silencing tumor-suppressive genes and activating key oncogenic pathways. Inhibition of COX-2 represents a mechanism-based target for HCC prevention.

Pharmacological inhibition of heparin-binding EGF-like growth factor promotes peritoneal angiogenesis in a peritoneal dialysis rat model

BACKGROUND

Molecular mechanisms of peritoneal dialysis (PD) ultrafiltration failure, peritoneal neo-angiogenesis, and fibrosis remain to be determined. We aimed to determine the role of heparin-binding EGF-like growth factor (HB-EGF) inhibition on angiogenesis of peritoneal membrane in a PD rat model.

METHODS

32 male Wistar rats were assigned into (1) control group; (2) uremic non-PD group: subtotal nephrectomy-induced uremic rats without PD; (3) uremic rats subjected to PD: uremic rats that were dialyzed with Dianeal^® for 4 weeks; (4) CRM 197 group: dialyzed uremic rats were supplemented with CRM197, a specific HB-EGF inhibitor. Peritoneal transport function was examined by peritoneal equilibration test. Expression of HB-EGF and EGFR in peritoneal samples were examined by real-time PCR, immunohistochemical staining, and western blot.

RESULTS

Progressive angiogenesis and fibrosis were observed in uremic PD rats, and there were associated with decreased net ultrafiltration (nUF), increased permeability of peritoneal membrane, and reduced expression of HB-EGF and EGFR protein and mRNA in uremic PD rats compared to uremic non-PD or control groups (both p < 0.05). CRM197 significantly induced peritoneal membrane permeability, decreased nUF, increased higher vessel density, and reduced pericyte count compared to that of uremic PD rats. The levels of HB-EGF and EGFR expression negatively correlated with vessel density in peritoneal membrane (both p < 0.001).

CONCLUSION

PD therapy was associated with peritoneal angiogenesis, functional deterioration, and downregulation of HB-EGF/EGFR. Pharmacological inhibition of HB-EGF promoted PD-induced peritoneal angiogenesis and fibrosis and ultrafiltration decline, suggesting that HB-EGF downregulation contributes to peritoneal functional deterioration in the uremic PD rat model.

HBEGF promotes gliomagenesis in the context of Ink4a/Arf and Pten loss

Heparin-binding epidermal growth factor (EGF)-like growth factor (HBEGF) is a ligand for the epidermal growth factor receptor (EGFR), one of the most commonly amplified receptor tyrosine kinases (RTK) in glioblastoma. While HBEGF has been found to be expressed in a subset of malignant gliomas, its sufficiency for glioma initiation has not been evaluated. In this study, we demonstrate that HBEGF can initiate glioblastoma (GBM) in mice in the context of Ink4a/Arf and Pten loss, and that these tumors are similar to the classical GBM subtype observed in patients. Isogenic astrocytes from these mice showed activation not only of Egfr but also the RTK Axl in response to HBEGF stimulation. Deletion of either Egfr or Axl decreased the tumorigenic properties of HBEGF transformed cells; however only EGFR was able to rescue the phenotype in cells lacking both RTKs indicating that Egfr is required for activation of Axl in this context. Silencing of HBEGF in vivo resulted in tumor regression and significantly increased survival suggesting that HBEGF may be a clinically relevant target.

Sleeping beauty: awakening urothelium from its slumber

The bladder urothelium is essentially quiescent but regenerates readily upon injury. The process of urothelial regeneration harkens back to the process of urothelial development whereby urothelial stem/progenitor cells must proliferate and terminally differentiate to establish all three urothelial layers. How the urothelium regulates the level of proliferation and the timing of differentiation to ensure the precise degree of regeneration is of significant interest in the field. Without a carefully-orchestrated process, urothelial regeneration may be inadequate, thereby exposing the host to toxins or pathogens. Alternatively, regeneration may be excessive, thereby setting the stage for tumor development. This review describes our current understanding of urothelial regeneration. The current controversies surrounding the identity and location of urothelial progenitor cells that mediate urothelial regeneration are discussed and evidence for each model is provided. We emphasize the factors that have been shown to be crucial for urothelial regeneration, including local growth factors that stimulate repair, and epithelial-mesenchymal cross talk, which ensures feedback regulation. Also highlighted is the emerging concept of epigenetic regulation of urothelial regeneration, which additionally fine tunes the process through transcriptional regulation of cell cycle genes and growth and differentiation factors. Finally, we emphasize how several of these pathways and/or programs are often dysregulated during malignant transformation, further corroborating their importance in directing normal urothelial regeneration. Together, evidence in the field suggests that any attempt to exploit regenerative programs for the purposes of enhanced urothelial repair or replacement must take into account this delicate balance.

Matrix Metalloproteinase 14 promotes lung cancer by cleavage of Heparin-Binding EGF-like Growth Factor

Molecularly targeted therapies benefit approximately 15–20% of non-small cell lung cancer (NSCLC) patients carrying specific drug-sensitive mutations. Thus, there is a clinically unmet need for the identification of novel targets for drug development. Here, we performed RNA-deep sequencing to identify altered gene expression between malignant and non-malignant lung tissue. Matrix Metalloproteinase 14 (MMP14), a membrane-bound proteinase, was significantly up-regulated in the tumor epithelial cells and intratumoral myeloid compartments in both mouse and human NSCLC. Overexpression of a soluble dominant negative MMP14 (DN-MMP14) or pharmacological inhibition of MMP14 blocked invasion of lung cancer cells through a collagen I matrix in vitro and reduced tumor incidence in an orthotopic K-Ras^G12D/+p53^−/− mouse model of lung cancer. Additionally, MMP14 activity mediated proteolytic processing and activation of Heparin-Binding EGF-like Growth Factor (HB-EGF), stimulating the EGFR signaling pathway to increase proliferation and tumor growth. This study highlights the potential for development of therapeutic strategies that target MMP14 in NSCLC with particular focus on MMP14-HB-EGF axis.

Novel 3-D cell culture system for in vitro evaluation of anticancer drugs under anchorage-independent conditions

Anticancer drug discovery efforts have used 2‐D cell‐based assay models, which fail to forecast in vivo efficacy and result in a lower success rate of clinical approval. Recent 3‐D cell culture models are expected to bridge the gap between 2‐D and in vivo models. However, 3‐D cell culture methods that are available for practical anticancer drug screening have not yet been fully attained. In this study, we screened several polymers for their ability to suspend cells or cell spheroids homogeneously in a liquid medium without changing the viscosity behavior, and identified gellan gum (FP001), as the most potent polymer. FP001 promoted cell dispersion in the medium and improved the proliferation of a wide range of cancer cell lines under low attachment conditions by inhibiting the formation of large‐sized spheroids. In addition, cancer cells cultured with FP001‐containing medium were more susceptible to inhibitors of epidermal growth factor (EGF) signaling than those cultured under attachment conditions. We also showed that ligands of the EGF receptor family clearly enhance proliferation of SKOV3 ovarian carcinoma cells under anchorage‐independent conditions with FP001. Consistent with this result, the cells grown with FP001 showed higher EGF receptor content compared with cells cultured under attachment conditions. In conclusion, we developed a novel 3‐D cell culture system that is available for high throughput screening of anticancer agents, and is suitable for evaluation of molecular‐targeted anticancer drugs. Three‐dimensional cell culture using FP001 will be of value in the development of useful technologies for anticancer drug discovery.

sMEK1 inhibits endothelial cell proliferation by attenuating VEGFR-2-dependent-Akt/eNOS/HIF-1α signaling pathways

The suppressor of MEK null (sMEK1) protein possesses pro-apoptotic activities. In the current study, we reveal that sMEK1 functions as a novel anti-angiogenic factor by suppressing vascular endothelial growth factor (VEGF)-induced cell proliferation, migration, and capillary-like tubular structure in vitro. In addition, sMEK1 inhibited the phosphorylation of the signaling components up- and downstream of Akt, including phospholipase Cγ1 (PLC-γ1), 3-phosphoinositide-dependent protein kinase 1 (PDK1), endothelial nitric oxide synthetase (eNOS), and hypoxia-inducible factor 1 (HIF-1α) during ovarian tumor progression via binding with vascular endothelial growth factor receptor 2 (VEGFR-2). Furthermore, sMEK1 decreased tumor vascularity and inhibited tumor growth in a xenograft human ovarian tumor model. These results supply convincing evidence that sMEK1 controls endothelial cell function and subsequent angiogenesis by suppressing VEGFR-2-mediated PI3K/Akt/eNOS signaling pathway. Taken together, our results clearly suggest that sMEK1 might be a novel anti-angiogenic and anti-tumor agent for use in ovarian tumor.

Annexin A2 and its downstream IL-6 and HB-EGF as secretory biomarkers in the differential diagnosis of Her-2 negative breast cancer

Background

AnnexinA2 (AnxA2) membrane deposition has a critical role in HB-EGF shedding as well as IL-6 secretion in breast cancer cells. This autocrine cycle has a major role in cancer cell proliferation, migration and metastasis. The objective of the study is to demonstrate annexinA2-mediated autocrine regulation via HB-EGF and IL-6 in Her-2 negative breast cancer progression.

Methods

Secretory annexinA2, HB-EGF and IL-6 were analysed in the peripheral blood sample of Her-2 negative ( n = 20) and positive breast cancer patients ( n = 16). Simultaneously, tissue expression was analysed by immunohistochemistry. The membrane deposition of these secretory ligands and their autocrine regulation was demonstrated using triple-negative breast cancer cell line model.

Results

Annexina2 and HB-EGF expression are inversely correlated with Her-2, whereas IL-6 expression is seen in both Her-2 negative and positive breast cancer cells. RNA interference studies and upregulation of annexinA2 proved that annexinA2 is the upstream of this autocrine pathway. Abundant soluble serum annexinA2 is secreted in Her-2 negative breast cancer (359.28 ± 63.73 ng/mL) compared with normal (286.10 ± 70.04 ng/mL, P < 0.01) and Her-2 positive cases (217.75 ± 60.59 ng/mL, P < 0.0001). In Her-2 negative cases, the HB-EGF concentrations (179.16 ± 118.81 pg/mL) were highly significant compared with normal (14.92 ± 17.33 pg/mL, P < 0.001). IL-6 concentrations were increased significantly in both the breast cancer phenotypes as compared with normal ( P < 0.001).

Conclusion

The specific expression pattern of annexinA2 and HB-EGF in triple-negative breast cancer tissues, increased secretion compared with normal cells, and their major role in the regulation of EGFR downstream signalling makes these molecules as a potential tissue and serum biomarker and an excellent therapeutic target in Her-2 negative breast cancer.

Co-Culture of Tumor Spheroids and Fibroblasts in a Collagen Matrix-Incorporated Microfluidic Chip Mimics Reciprocal Activation in Solid Tumor Microenvironment

Multicellular 3D culture and interaction with stromal components are considered essential elements in establishing a ‘more clinically relevant’ tumor model. Matrix-embedded 3D cultures using a microfluidic chip platform can recapitulate the microscale interaction within tumor microenvironments. As a major component of tumor microenvironment, cancer-associated fibroblasts (CAFs) play a role in cancer progression and drug resistance. Here, we present a microfluidic chip-based tumor tissue culture model that integrates 3D tumor spheroids (TSs) with CAF in proximity within a hydrogel scaffold. HT-29 human colorectal carcinoma cells grew into 3D TSs and the growth was stimulated when co-cultured with fibroblasts as shown by 1.5-folds increase of % changes in diameter over 5 days. TS cultured for 6 days showed a reduced expression of Ki-67 along with increased expression of fibronectin when co-cultured with fibroblasts compared to mono-cultured TSs. Fibroblasts were activated under co-culture conditions, as demonstrated by increases in α-SMA expression and migratory activity. When exposed to paclitaxel, a survival advantage was observed in TSs co-cultured with activated fibroblasts. Overall, we demonstrated the reciprocal interaction between TSs and fibroblasts in our 7-channel microfluidic chip. The co-culture of 3D TS-CAF in a collagen matrix-incorporated microfluidic chip may be useful to study the tumor microenvironment and for evaluation of drug screening and evaluation.

YBX1/YB-1 induces partial EMT and tumourigenicity through secretion of angiogenic factors into the extracellular microenvironment

Epithelial-mesenchymal transition (EMT) describes a morphogenetic program which confers mesenchymal cell properties, such as reduced cell-cell contact and increased cell migration and invasion, to epithelial cells. Here we investigate the role of the pleiotropic transcription/splicing factor and RNA-binding protein nuclease-sensitive element-binding protein 1 (YBX1/YB-1) in increasing the oncogenic potential of epithelial MDCK cells. Characterization of MDCK cells expressing YBX1 (MDCK^YBX1 cells) revealed a partial EMT phenotype, including cytosolic relocalization of E-cadherin, increased cell scattering, and anchorage-independent growth. Subcutaneous injection of parental MDCK cells into NOD/SCID mice did not form tumours. Critically, MDCK^YBX1 cells established viable tumour xenografts, and immuno-histochemical staining indicated murine vascularization by CD31+ endothelial cells. We analysed the total secretome (containing soluble and extracellular vesicles) of MDCK^YBX1 cells to investigate regulation of the tumour microenvironment. YBX1 expression elevated release of secreted factors known to enhance angiogenesis (TGF-β, CSF-1, NGF, VGF, ADAM9 and ADAM17), compared to MDCK cells. Importantly, treatment with MDCK^YBX1 cell-derived secretome increased recipient 2F-2B endothelial cell motility. This defines YBX1 as an oncogenic enhancer that can regulate tumour angiogenesis via release of secreted modulators into the extracellular microenvironment.

Up-regulation of HB-EGF by the COX-2/PGE2 signaling associates with the cisplatin resistance and tumor recurrence of advanced HNSCC

OBJECTIVES

When treating advanced HNSCC, a cisplatin-based systemic regimen benefit patient survival. However, chemoresistance will greatly reduce the effectiveness of this approach. The identification of molecules that contribute to cisplatin resistance may potentially improve the survival. Both HB-EGF and COX-2 have been reported to increase cisplatin-resistance. Here, we have focused on the regulation of HB-EGF/COX-2 and their roles in cisplatin resistance.

MATERIALS AND METHODS

IHC staining was used to measure the expression levels of HB-EGF and COX-2 on the tissue microarray from 43 tissue samples of patients with advanced HNSCC. siRNA, western blot and qRT-PCR were used to dissect the regulation between EGF, Akt, COX-2, PGE2, and cisplatin sensitivity. The correlation between HB-EGF, COX2 and HNSCC progression was analyzed by the receiver operating characteristic (ROC) curve and Kaplan-Meier disease free survival.

RESULTS

Patients of advanced HNSCC patients with increased HB-EGF and COX-2 expression have higher tumor recurrent rates that was related to cisplatin resistance. The resistance was mediated via an increased expression of HB-EGF and COX-2. The activation of Akt by either EGF or areca nut extract were able to upregulate COX-2, which would increase the expression of HB-EGF in a PGE2 dependent manner. Inhibition and knockdown of COX-2 resulted in a decrease in HB-EGF. In the tissue samples from HNSCC patients, there was a significant positive correlation between the expression of COX-2 and HB-EGF.

CONCLUSION

Our results suggested that COX-2 and HB-EGF are important in development of HNSCC cisplatin resistance. These findings may help the development of new strategies for overcoming cisplatin resistance.