Epithelial Mesenchymal Transition: a double-edged sword

MMPs as potential molecular targets in epithelial-to-mesenchymal transition driven COPD progression

Chronic obstructive pulmonary disease (COPD) is the third leading cause of mortality globally and the risk of developing lung cancer is six times greater in individuals with COPD who smoke compared to those who do not smoke. Matrix metalloproteinases (MMPs) play a crucial role in the pathophysiology of respiratory diseases by promoting inflammation and tissue degradation. Furthermore, MMPs are involved in key processes like epithelial-to-mesenchymal transition (EMT), metastasis, and invasion in lung cancer. While EMT has traditionally been associated with the progression of lung cancer, recent research highlights its active involvement in individuals with COPD. Current evidence underscores its role in orchestrating airway remodeling, fostering airway fibrosis, and contributing to the potential for malignant transformation in the complex pathophysiology of COPD. The precise regulatory roles of diverse MMPs in steering EMT during COPD progression needs to be elucidated. Additionally, the less-understood aspect involves how these MMPs bi-directionally activate or regulate various EMT-associated signaling cascades during COPD progression. This review article explores recent advancements in understanding MMPs' role in EMT during COPD progression and various pharmacological approaches to target MMPs. It also delves into the limitations of current MMP inhibitors and explores novel, advanced strategies for inhibiting MMPs, potentially offering new avenues for treating respiratory diseases.

Aryl Hydrocarbon Receptor Activation in Pulmonary Alveolar Epithelial Cells Limits Inflammation and Preserves Lung Epithelial Cell Integrity

The aryl hydrocarbon receptor (AHR) is a receptor/transcription factor widely expressed in the lung. The physiological roles of AHR expressed in the alveolar epithelium remain unclear. In this study, we tested the hypothesis that alveolar epithelial AHR activity plays an important role in modulating inflammatory responses and maintaining alveolar integrity during lung injury and repair. AHR is expressed in alveolar epithelial cells (AECs) and is active. AHR activation with the endogenous AHR ligand, FICZ (5,11-dihydroindolo[3,2-b] carbazole-6-carboxaldehyde), significantly suppressed inflammatory cytokine expression in response to inflammatory stimuli in primary murine AECs and in the MLE-15 epithelial cell line. In an LPS model of acute lung injury in mice, coadministration of FICZ with LPS suppressed protein leak, reduced neutrophil accumulation in BAL fluid, and suppressed inflammatory cytokine expression in lung tissue and BAL fluid. Relevant to healing following inflammatory injury, AHR activation suppressed TGF-β-induced expression of genes associated with epithelial-mesenchymal transition. Knockdown of AHR in primary AECs with shRNA or in CRISPR-Cas-9-induced MLE-15 cells resulted in upregulation of α-smooth muscle actin (αSma), Col1a1, and Fn1 and reduced expression of epithelial genes Col4a1 and Sdc1. MLE-15 clones lacking AHR demonstrated accelerated wound closure in a scratch model. AHR activation with FICZ enhanced barrier function (transepithelial electrical resistance) in primary murine AECs and limited decline of transepithelial electrical resistance following inflammatory injury. AHR activation in AECs preserves alveolar integrity by modulating inflammatory cytokine expression while enhancing barrier function and limiting stress-induced expression of mesenchymal genes.

ARID1A-BAF coordinates ZIC2 genomic occupancy for epithelial-to-mesenchymal transition in cranial neural crest specification

The BAF chromatin remodeler regulates lineage commitment including cranial neural crest cell (CNCC) specification. Variants in BAF subunits cause Coffin-Siris syndrome (CSS), a congenital disorder characterized by coarse craniofacial features and intellectual disability. Approximately 50% of individuals with CSS harbor variants in one of the mutually exclusive BAF subunits, ARID1A/ARID1B. While Arid1a deletion in mouse neural crest causes severe craniofacial phenotypes, little is known about the role of ARID1A in CNCC specification. Using CSS-patient-derived ARID1A+/- induced pluripotent stem cells to model CNCC specification, we discovered that ARID1A-haploinsufficiency impairs epithelial-to-mesenchymal transition (EMT), a process necessary for CNCC delamination and migration from the neural tube. Furthermore, wild-type ARID1A-BAF regulates enhancers associated with EMT genes. ARID1A-BAF binding at these enhancers is impaired in heterozygotes while binding at promoters is unaffected. At the sequence level, these EMT enhancers contain binding motifs for ZIC2, and ZIC2 binding at these sites is ARID1A-dependent. When excluded from EMT enhancers, ZIC2 relocates to neuronal enhancers, triggering aberrant neuronal gene activation. In mice, deletion of Zic2 impairs NCC delamination, while ZIC2 overexpression in chick embryos at post-migratory neural crest stages elicits ectopic delamination from the neural tube. These findings reveal an essential ARID1A-ZIC2 axis essential for EMT and CNCC delamination.

An Antibody of the Secreted Isoform of Disintegrin and Metalloprotease 9 (sADAM9) Inhibits Epithelial-Mesenchymal Transition and Migration of Prostate Cancer Cell Lines

Prostate cancer (PC) is the most common cancer diagnosed in men worldwide. Currently, castration-resistant prostate cancer (CRPC), which is resistant to androgen deprivation therapy, has a poor prognosis and is a therapeutic problem. We investigated the antitumor effects on PC of an antibody neutralizing secreted disintegrin and metalloproteinase domain-containing protein 9 (sADAM9), which is a blood-soluble form. We performed proliferation assays, wound healing assays, invasion assays, Western blot (WB), and an in vivo study in which a sADAM9 neutralizing antibody was administered intratumorally to PC-bearing mice. In invasion assays, the sADAM9 neutralizing antibody significantly inhibited invasion in all cell lines (TRAMP-C2: p = 0.00776, LNCaP: p = 0.000914, PC-3: p = 0.0327, and DU145: p = 0.0254). We examined epithelial-mesenchymal transition (EMT) markers, one of the metastatic mechanisms, in WB and showed downregulation of Slug in TRAMP-C2, LNCaP, and DU145 and upregulation of E-cadherin in TRAMP-C2 and PC-3 by sADAM9 neutralization. In mouse experiments, the sADAM9 neutralizing antibody significantly suppressed tumor growth compared to controls (1.68-fold in TRAMP-C2, 1.89-fold in LNCaP, and 2.67-fold in PC-3). These results suggested that the sADAM9 neutralizing antibody inhibits invasion, migration, and tumor growth in PC. Previous studies examined the anti-tumor effect of knockdown of total ADAM9 or sADAM9, but this study used the new technology of neutralizing antibodies for sADAM9. This may be novel because there was no animal study using a neutralizing antibody for sADAM9 to see the relationship between ADAM9 expression and prostate cancer.

Epithelial-mesenchymal Transition (EMT) and the Effect of Atorvastatin on it in ARPE-19 cells

Proliferative vitreoretinopathy (PVR) develops after an unsuccessful or complicated recovery from rhegmatogenous retinal detachment (RRD) surgery. Intraocular scar formation with the contribution of epithelial-mesenchymal transition (EMT) in RPE cells is prominent in the pathology of PVR. In the present study, the EMT process was experimentally induced in human retinal pigment epithelium (RPE; ARPE-19) cells, and the effect of atorvastatin on the process was studied. The mRNA and protein levels of mesenchymal markers actin alpha 2 (ACTA2) / alpha-smooth muscle actin (α-SMA) and fibronectin (FN), and epithelial markers occludin (OCLN) and zonula occludens-1 (ZO-1) were measured using quantitative real-time PCR (qRT-PCR) and western blot methods, respectively. In addition, α-SMA and FN were visualized using immunofluorescence staining. Cells were photographed under a phase contrast light microscope. Changes in the functionality of cells following the EMT process were studied using the IncuCyte scratch wound cell migration assay and the collagen cell invasion assay with confocal microscopy. The induction of EMT in ARPE-19 cells increased the expression of mesenchymal markers ACTA2/α-SMA and fibronectin and reduced the expression of epithelial marker OCLN both at mRNA and protein levels. The mRNA levels of ZO-1 were lower after EMT, as well. Increased levels of α-SMA and FN were confirmed by immunofluorescence staining. Atorvastatin further increased the mRNA levels of mesenchymal markers ACTA2 and FN as well as the protein levels of α-SMA and reduced the mRNA levels of epithelial markers OCLN and ZO-1 under the EMT process. EMT promoted wound closure and cell invasion into the 3D collagen matrix when compared to untreated control cells. These data present cellular changes upon the induction of the EMT process in ARPE-19 cells and the propensity of atorvastatin to complement the effect. More studies are needed to confirm the exact influence of the EMT process and atorvastatin treatment on the PVR development after RRD surgery.

Acidic fibroblast growth factor inhibits reactive oxygen species-induced epithelial-mesenchymal transdifferentiation in vascular endothelial cells via the miR-155-5p/SIRT1/Nrf2/HO-1 pathway to promote wound healing in diabetic mice

Background

Diabetic chronic wounds are among the most common and serious complications of diabetes and are associated with significant morbidity and mortality. Endothelial-to-mesenchymal transition (EndMT) is a specific pathological state in which endothelial cells are transformed into mesenchymal cells in response to various stimuli, such as high glucose levels and high oxidative stress. Acidic fibroblast growth factor (aFGF), which is a member of the fibroblast growth factor family, possesses strong antioxidant properties and can promote the differentiation of mesenchymal stem cells into angiogenic cells. Therefore, we investigated the role of aFGF in EndMT in diabetic wounds and analysed the underlying mechanisms.

Methods

A diabetic mouse model was used to verify the effect of aFGF on wound healing, and the effect of aFGF on vascular endothelial cells in a high-glucose environment was examined in vitro. We examined the expression of miR-155-5p in a high-glucose environment and the miR-155 downstream target gene SIRT1 by luciferase reporter assays.

Results

aFGF promoted wound closure and neovascularization in a mouse model of type 2 diabetes. In vitro, aFGF inhibited the production of total and mitochondrial reactive oxygen species (ROS) in vascular endothelial cells and alleviated epithelial-mesenchymal transdifferentiation in a high-glucose environment. Mechanistically, aFGF promoted the expression of SIRT1 and the downstream targets Nrf2 and HO-1 by negatively regulating miR-155-5p, thereby reducing ROS generation.

Conclusions

In conclusion, our results suggest that aFGF inhibits ROS-induced epithelial-mesenchymal transdifferentiation in diabetic vascular endothelial cells via the miR-155-5p/SIRT1/Nrf2/HO-1 axis, thereby promoting wound healing.

Enhanced epithelial-mesenchymal transition signatures are linked with adverse tumor microenvironment, angiogenesis and worse survival in gastric cancer

Epithelial-mesenchymal transition (EMT) is a crucial mechanism that facilitates cancer cell metastasis. Despite its importance, the clinical significance of EMT in gastric cancer (GC) patients has yet to be clearly demonstrated. For gauging the extent of EMT in GC, we employed gene set variation analysis to score 807 patient samples from two large cohorts: TCGA and GSE84437. In both cohorts, EMT high GC showed a significant association with worse overall survival (hazard ratio (HR) = 1.74, p = 0.011 and HR = 2.01, p < 0.001, respectively). This association was stronger when considering the EMT signature score compared to the individual expressions of EMT-related genes (CDH1, CDH2, VIM, and FN1). While the EMT signature level did not differ among various cancers, high EMT signature specifically correlated with survival in GC alone. Mucinous and diffuse histological types exhibited higher EMT levels compared to others (p < 0.001), and the EMT signature level was correlated with tumor depth and AJCC stage (all p < 0.001). Interestingly, the EMT score was an independent factor for overall and disease-specific survival (multivariate; p = 0.006 and 0.032, respectively). EMT high GC displayed a lower fraction of Th1 cells and a higher fraction of dendritic cells, M1 macrophages and several stromal cells. EMT high GC exhibited an inverse correlation with cell proliferation-related gene sets. While they significantly enriched multiple pro-cancerous gene sets, such as TGF-β signaling, hypoxia, and angiogenesis. The presence of EMT signature in a bulk tumor was linked to TGF-β signaling, hypoxia, and angiogenesis, and was also associated with poorer survival outcomes in GC patients.

Unraveling the molecular mechanisms of cell migration impairment and apoptosis associated with steroid sulfatase deficiency: Implications for X-linked ichthyosis

Steroid sulfatase (STS) deficiency is responsible for X-linked ichthyosis (XLI), a genetic disorder characterized by rough and dry skin caused by excessive keratinization. The impaired keratinization process leads to reduced cell mobility and increased apoptosis, which can cause an excessive buildup of the stratum corneum. In this study, we investigated the mechanisms underlying XLI and found that STS deficiency reduces cell mobility and increases apoptosis in human keratinocyte HaCaT cells. To explore these mechanisms further, RNA-sequencing was conducted on skin tissues from STS transgenic and knockout mice. Our RNA-seq results revealed that STS deficiency plays a critical role in regulating multiple signaling pathways associated with cell mobility and apoptosis, such as Wnt/β signaling and the Hippo signaling pathway. Knockdown of the STS gene using shRNA in HaCaT cells led to an upregulation of E-cadherin expression and suppression of key factors involved in epithelial-mesenchymal transition (EMT), such as N-cadherin and vimentin. Inhibition of EMT involved the Hippo signaling pathway and reduction of HIF-1α. Interestingly, inhibiting STS with shRNA increased mitochondrial respiration levels, as demonstrated by the extracellular flux oxygen consumption rate. Additionally, we observed a significant increase in ROS production in partial STS knockout cells compared to control cells. Our study demonstrated that the excessive generation of ROS caused by STS deficiency induces the expression of Bax and Bak, leading to the release of cytochrome c and subsequent cell death. Consequently, STS deficiency impairs cell mobility and promotes apoptosis, offering insights into the pathophysiological processes and potential therapeutic targets for XLI.

Harnessing function of EMT in cancer drug resistance: a metastasis regulator determines chemotherapy response

Epithelial-mesenchymal transition (EMT) is a complicated molecular process that governs cellular shape and function changes throughout tissue development and embryogenesis. In addition, EMT contributes to the development and spread of tumors. Expanding and degrading the surrounding microenvironment, cells undergoing EMT move away from the main location. On the basis of the expression of fibroblast-specific protein-1 (FSP1), fibroblast growth factor (FGF), collagen, and smooth muscle actin (-SMA), the mesenchymal phenotype exhibited in fibroblasts is crucial for promoting EMT. While EMT is not entirely reliant on its regulators like ZEB1/2, Twist, and Snail proteins, investigation of upstream signaling (like EGF, TGF-β, Wnt) is required to get a more thorough understanding of tumor EMT. Throughout numerous cancers, connections between tumor epithelial and fibroblast cells that influence tumor growth have been found. The significance of cellular crosstalk stems from the fact that these events affect therapeutic response and disease prognosis. This study examines how classical EMT signals emanating from various cancer cells interfere to tumor metastasis, treatment resistance, and tumor recurrence.

Idiopathic Subglottic Stenosis Is Associated With More Frequent and Abnormal Squamous Metaplasia

OBJECTIVES

Gain insights into the pathophysiology of idiopathic subglottic stenosis (iSGS) by investigating differences in transcriptome of subglottic mucosal tissue between patients with iSGS and controls, and between tracheal and subglottic tissue within patients.

METHODS

RNA sequencing was conducted on biopsied mucosal samples collected from subglottic and tracheal (in-patient control) regions in iSGS patients, and from subglottis in controls. The gene expression differences were validated on a protein level by (1) staining the tissue samples obtained from a second cohort of patients and controls; and (2) in vitro functional assays using primary subglottic epithelial cells from both iSGS patients and healthy donors.

RESULTS

We found 7 upregulated genes in the subglottic region of iSGS patients relative to both the tracheal mucosa and subglottic region of controls. A gene ontology enrichment analysis found that the epithelial cell differentiation and cornification pathways are significant, involving specifically 3 of the genes: involucrin (IVL), small proline rich protein 1B (SPRR1B), and keratin 16 (KRT16). Involvement of these pathways suggests squamous metaplasia of the epithelium. Histological analyses of epithelium in subglottic mucosal biopsies revealed squamous metaplasia in 41% of the samples from iSGS patients and in 25% from controls. Immunohistochemical evaluation of the samples presented with squamous epithelium revealed increased expression of the protein encoded by SPRR1B, hyperproliferative basal cells, shedding of apical layers, and accompanying lesions in iSGS compared to CTRL. Cultured primary subglottic epithelial cells from iSGS patients had higher proliferation rates compared to healthy donors and squamous metaplastic differentiation formed thinner epithelia with increased expression proteins encoded by INV, SPRR1B, and KRT16, suggesting intrinsic dysfunction of basal cells in iSGS.

CONCLUSIONS

Abnormal squamous differentiation of epithelial cells may contribute to the pathogenesis of iSGS. Patients having metaplastic epithelial phenotype may be sensitive to drugs that reverse it to a normal phenotype.

Bitter Phytochemicals as Novel Candidates for Skin Disease Treatment

Skin diseases represent a global healthcare challenge due to their rising incidence and substantial socio-economic burden. While biological, immunological, and targeted therapies have brought a revolution in improving quality of life and survival rates for certain dermatological conditions, there remains a stringent demand for new remedies. Nature has long served as an inspiration for drug development. Recent studies have identified bitter taste receptors (TAS2Rs) in both skin cell lines and human skin. Additionally, bitter natural compounds have shown promising benefits in addressing skin aging, wound healing, inflammatory skin conditions, and even skin cancer. Thus, TAS2Rs may represent a promising target in all these processes. In this review, we summarize evidence supporting the presence of TAS2Rs in the skin and emphasize their potential as drug targets for addressing skin aging, wound healing, inflammatory skin conditions, and skin carcinogenesis. To our knowledge, this is a pioneering work in connecting information on TAS2Rs expression in skin and skin cells with the impact of bitter phytochemicals on various beneficial effects related to skin disorders.

The Prognosis of Cancer Depends on the Interplay of Autophagy, Apoptosis, and Anoikis within the Tumor Microenvironment

Within the tumor microenvironment, the fight between the immune system and cancer influences tumor transformation. Metastasis formation is an important stage in the progression of cancer. This process is aided by cellular detachment and resistance to anoikis, which are achieved by altering intercellular signaling. Autophagy, specifically pro-survival autophagy, aids cancer cells in developing treatment resistance. Numerous studies have shown that autophagy promotes tumor growth and resistance to anoikis. To regulate protective autophagy, cancer-related genes phosphorylate both pro- and anti-apoptotic proteins. Apoptosis, a type of controlled cell death, eliminates damaged or unwanted cells. Anoikis is a type of programmed cell death in which cells lose contact with the extracellular matrix. The dysregulation of these cellular pathways promotes tumor growth and spread. Apoptosis, anoikis, and autophagy interact meticulously and differently depending on the cellular circumstances. For instance, autophagy can protect cancer cells from apoptosis by removing cellular components that are damaged and might otherwise trigger apoptotic pathways. Similarly, anoikis dysregulation can trigger autophagy by causing cellular harm and metabolic stress. In order to prevent or treat metastatic disease, specifically, targeting these cellular mechanisms may present a promising prospect for cancer therapy. This review discourses the state of our understanding of the molecular and cellular mechanisms underlying tumor transformation and the establishment of metastatic tumors. To enhance the prognosis for cancer, we highlight and discuss potential therapeutic approaches that target these processes and genes involved in them.

Impaired angiogenesis in ageing: the central role of the extracellular matrix

Each step in angiogenesis is regulated by the extracellular matrix (ECM). Accumulating evidence indicates that ageing-related changes in the ECM driven by cellular senescence lead to a reduction in neovascularisation, reduced microvascular density, and an increased risk of tissue ischaemic injury. These changes can lead to health events that have major negative impacts on quality of life and place a significant financial burden on the healthcare system. Elucidating interactions between the ECM and cells during angiogenesis in the context of ageing is neceary to clarify the mechanisms underlying reduced angiogenesis in older adults. In this review, we summarize ageing-related changes in the composition, structure, and function of the ECM and their relevance for angiogenesis. Then, we explore in detail the mechanisms of interaction between the aged ECM and cells during impaired angiogenesis in the older population for the first time, discussing diseases caused by restricted angiogenesis. We also outline several novel pro-angiogenic therapeutic strategies targeting the ECM that can provide new insights into the choice of appropriate treatments for a variety of age-related diseases. Based on the knowledge gathered from recent reports and journal articles, we provide a better understanding of the mechanisms underlying impaired angiogenesis with age and contribute to the development of effective treatments that will enhance quality of life.

Morbidity and Mortality in Neonates with Symptomatic Congenital Lung Malformation

BACKGROUND

Neonatal resection is the mainstay treatment of children presenting with symptomatic congenital lung malformation (CLM) at birth. The objective of this study was to evaluate risk factors for increased morbidity and mortality after neonatal CLM resection using a large multicenter database.

STUDY DESIGN

Retrospective review of the Pediatric Health Information System database was performed. Children with a symptomatic CLM managed by lung resection before 30 days of age were included (2016 to 2021). Primary outcomes measures were postoperative respiratory complication and any complication, including death.

RESULTS

Of 1,791 CLM patients identified, 256 (14%) underwent neonatal resection for symptomatic disease. Pathology included 123 (48%) congenital pulmonary airway malformation, 24 (10%) bronchopulmonary sequestration, 5 (2%) congenital lobar emphysema, 16 (6%) hybrid, and 88 (34%) unclassified lesion. Preoperative mechanical ventilation and extracorporeal membrane oxygenation (ECMO) were employed in 149 (58.2%) and 17 (6.7%) of cases, respectively. The median age at resection was 6.5 days (interquartile range 2 to 23). Postoperatively, 25 (10%) required mechanical ventilation for 48 hours or more, 3 (1%) continued ECMO, and 3 (1%) required ECMO rescue. The overall respiratory complication rate was 34% (87), rate of any complication was 51% (130), median postoperative length of stay was 20 days (interquartile range 9 to 52), and mortality rate was 14.5% (37). Birthweight was inversely correlated with complication risk (incidence rate ratio 0.55, 95% CI 0.36 to 0.83, p = 0.006). Cardiac structural anomaly was associated with a 21-day longer postoperative length of stay (95% CI 6 to 35, p = 0.006) and 2.2 times increased risk of any complication (95% CI 1.18 to 4.02, p = 0.014).

CONCLUSIONS

In this large multicenter study, ECMO use and mortality are relatively uncommon among neonates undergoing lung resection for a symptomatic CLM. However, postoperative morbidity remains high, particularly in those with cardiac structural disease.

Human pancreatic cancer patients with Epithelial-to-Mesenchymal Transition and an aggressive phenotype show a disturbed balance in Protein Phosphatase Type 2A expression and functionality

BACKGROUND

Pancreatic ductal adenocarcinoma (PDAC) has a low survival, its incidence is rising and little therapeutic improvements are expected in the near future. It has been observed that Epithelial-to-Mesenchymal transition (EMT) contributes (including in PDAC) to a more aggressive cancer phenotype. Additionally, largely unexplored, studies indicate a mechanistic interplay between Protein Phosphatase Type 2A (PP2A) enzymes and EMT that could offer treatment opportunities. The aim was to investigate the relation of a PP2A expression signature (encompassing all PP2A subunits, endogenous inhibitors and activators) with EMT and aggressive pancreatic cancer, and to discuss possible implications.

METHODS

We retrieved different PDAC expression datasets from NCBI to capture the variation in patients, and analyzed these using datamining, survival analysis, differential gene and protein expression. We determined genes highly associated with aggressive PDAC. For in vitro evaluation, Panc-1 cells were treated with the pharmacologic PP2A inhibitor Okadaic Acid (OA). Additionally, two OA-resistant Panc-1 clones were developed and characterized.

RESULTS

In patients, there is a strong correlation between EMT and aggressive PDAC, and between aggressive PDAC and PP2A, with a significant upregulation of PP2A inhibitor genes. Several PP2A genes significantly correlated with decreased survival. In vitro, short-term exposure to OA induced EMT in Panc-1 cells. This shift towards EMT was further pronounced in the OA-resistant Panc-1 clones, morphologically and by pathway analysis. Proteomic analysis and gene sequencing showed that the advanced OA-resistant model most resembles the clinical PDAC presentation (with EMT signature, and with several specific PP2A genes upregulated, and others downregulated).

CONCLUSIONS

We demonstrated a strong association between EMT, altered PP2A expression and aggressive PDAC in patients. Also, in vitro, PP2A inhibition induces EMT. Overall, statistics suggests the mechanistic importance of PP2A dysregulation for PDAC progression. Translationally, our observations indicate that pharmacologic restoration of PP2A activity could be an attractive therapeutic strategy to block or reverse progression.

Epithelial-to-Mesenchymal Transition-Related Markers in Prostate Cancer: From Bench to Bedside

Prostate cancer (PCa) is the second most frequent type of cancer in men worldwide, with 288,300 new cases and 34,700 deaths estimated in the United States in 2023. Treatment options for early-stage disease include external beam radiation therapy, brachytherapy, radical prostatectomy, active surveillance, or a combination of these. In advanced cases, androgen-deprivation therapy (ADT) is considered the first-line therapy; however, PCa in most patients eventually progresses to castration-resistant prostate cancer (CRPC) despite ADT. Nonetheless, the transition from androgen-dependent to androgen-independent tumors is not yet fully understood. The physiological processes of epithelial-to-non-epithelial ("mesenchymal") transition (EMT) and mesenchymal-to-epithelial transition (MET) are essential for normal embryonic development; however, they have also been linked to higher tumor grade, metastatic progression, and treatment resistance. Due to this association, EMT and MET have been identified as important targets for novel cancer therapies, including CRPC. Here, we discuss the transcriptional factors and signaling pathways involved in EMT, in addition to the diagnostic and prognostic biomarkers that have been identified in these processes. We also tackle the various studies that have been conducted from bench to bedside and the current landscape of EMT-targeted therapies.

A2B Adenosine Receptor in Idiopathic Pulmonary Fibrosis: Pursuing Proper Pit Stop to Interfere with Disease Progression

Purine nucleotides and nucleosides are involved in various human physiological and pathological mechanisms. The pathological deregulation of purinergic signaling contributes to various chronic respiratory diseases. Among the adenosine receptors, A2B has the lowest affinity such that it was long considered to have little pathophysiological significance. Many studies suggest that A2BAR plays protective roles during the early stage of acute inflammation. However, increased adenosine levels during chronic epithelial injury and inflammation might activate A2BAR, resulting in cellular effects relevant to the progression of pulmonary fibrosis.

Beyond the Scar: A Basic Science Review of Wound Remodeling

Significance: Increasing development of experimental animal models has allowed for the study of scar formation. However, many pathophysiological unknowns remain in the longest stage of healing, the remodeling stage, which may continue for a year or more. The wound healing process results in different types of scarring classified as normal or pathological depending on failures at each stage. Failures can also occur during wound remodeling, but the molecular mechanisms driving the wound remodeling process have yet to be investigated. Recent Advances: While the current understanding of wound repair is based on investigations of acute healing, these experimental models have informed knowledge of key components of remodeling. This review examines the components that contribute to collagen organization and the final scar, including cell types, their regulation, and signaling pathways. Dysregulation in any one of these components causes pathologic healing. Critical Issues and Future Directions: As wounds continue to remodel months to years after reepithelialization, new models to better understand long-term remodeling will be critical for improving healing outcomes. Further investigation of the contributions of fibroblasts and cell signaling pathways involved during remodeling as well as their potential failures may inform new approaches in promoting regenerative healing beyond reepithelialization.

ST3GAL5-catalyzed gangliosides inhibit TGF-β-induced epithelial-mesenchymal transition via TβRI degradation

Epithelial-mesenchymal transition (EMT) is pivotal in the initiation and development of cancer cell metastasis. We observed that the abundance of glycosphingolipids (GSLs), especially ganglioside subtypes, decreased significantly during TGF-β-induced EMT in NMuMG mouse mammary epithelial cells and A549 human lung adenocarcinoma cells. Transcriptional profiling showed that TGF-β/SMAD response genes and EMT signatures were strongly enriched in NMuMG cells, along with depletion of UDP-glucose ceramide glucosyltransferase (UGCG), the enzyme that catalyzes the initial step in GSL biosynthesis. Consistent with this finding, genetic or pharmacological inhibition of UGCG promoted TGF-β signaling and TGF-β-induced EMT. UGCG inhibition promoted A549 cell migration, extravasation in the zebrafish xenograft model, and metastasis in mice. Mechanistically, GSLs inhibited TGF-β signaling by promoting lipid raft localization of the TGF-β type I receptor (TβRI) and by increasing TβRI ubiquitination and degradation. Importantly, we identified ST3GAL5-synthesized a-series gangliosides as the main GSL subtype involved in inhibition of TGF-β signaling and TGF-β-induced EMT in A549 cells. Notably, ST3GAL5 is weakly expressed in lung cancer tissues compared to adjacent nonmalignant tissues, and its expression correlates with good prognosis.

Opposing USP19 splice variants in TGF-β signaling and TGF-β-induced epithelial-mesenchymal transition of breast cancer cells

Ubiquitin-specific protease (USP)19 is a deubiquitinating enzyme that regulates the stability and function of multiple proteins, thereby controlling various biological responses. The alternative splicing of USP19 results in the expression of two major encoded variants that are localized to the endoplasmic reticulum (ER) (USP19-ER) and cytoplasm (USP19-CY). The importance of alternative splicing for the function of USP19 remains unclear. Here, we demonstrated that USP19-CY promotes TGF-β signaling by directly interacting with TGF-β type I receptor (TβRI) and protecting it from degradation at the plasma membrane. In contrast, USP19-ER binds to and sequesters TβRI in the ER. By decreasing cell surface TβRI levels, USP19-ER inhibits TGF-β/SMAD signaling in a deubiquitination-independent manner. Moreover, USP19-ER inhibits TGF-β-induced epithelial-mesenchymal transition (EMT), whereas USP19-CY enhances EMT, as well as the migration and extravasation of breast cancer cells. Furthermore, USP19-CY expression is correlated with poor prognosis and is higher in breast cancer tissues than in adjacent normal tissues. Notably, the splicing modulator herboxidiene inhibits USP19-CY, increases USP19-ER expression and suppresses breast cancer cell migration. Targeting USP19 splicing or its deubiquitinating activity may have potential therapeutic effects on breast cancer.

Single-cell transcriptomics identifies Keap1-Nrf2 regulated collective invasion in a Drosophila tumor model

Apicobasal cell polarity loss is a founding event in epithelial-mesenchymal transition and epithelial tumorigenesis, yet how pathological polarity loss links to plasticity remains largely unknown. To understand the mechanisms and mediators regulating plasticity upon polarity loss, we performed single-cell RNA sequencing of Drosophila ovaries, where inducing polarity-gene l(2)gl-knockdown (Lgl-KD) causes invasive multilayering of the follicular epithelia. Analyzing the integrated Lgl-KD and wildtype transcriptomes, we discovered the cells specific to the various discernible phenotypes and characterized the underlying gene expression. A genetic requirement of Keap1-Nrf2 signaling in promoting multilayer formation of Lgl-KD cells was further identified. Ectopic expression of Keap1 increased the volume of delaminated follicle cells that showed enhanced invasive behavior with significant changes to the cytoskeleton. Overall, our findings describe the comprehensive transcriptome of cells within the follicle cell tumor model at the single-cell resolution and identify a previously unappreciated link between Keap1-Nrf2 signaling and cell plasticity at early tumorigenesis.

Epithelial-mesenchymal transition-related long noncoding RNAs in gastric carcinoma

As an evolutionarily phenotypic conversion program, the epithelial-mesenchymal transition (EMT) has been implicated in tumour deterioration and has facilitated the metastatic ability of cancer cells via enhancing migration and invasion. Gastric cancer (GC) remains a frequently diagnosed non-skin malignancy globally. Most GC-associated mortality can be attributed to metastasis. Recent studies have shown that EMT-related long non-coding RNAs (lncRNAs) play a critical role in GC progression and GC cell motility. In addition, lncRNAs are associated with EMT-related transcription factors and signalling pathways. In the present review, we comprehensively described the EMT-inducing lncRNA molecular mechanisms and functional perspectives of EMT-inducing lncRNAs in GC progression. Taken together, the statements of this review provided a clinical implementation in identifying lncRNAs as potential therapeutic targets for advanced GC.

Plasma and Peritoneal Fluid ZEB Levels in Patients with Endometriosis and Infertility

Zinc finger E-box-binding homeobox 1 (ZEB1) and zinc finger E-box-binding homeobox 2 (ZEB2) are transcription factors that regulate epithelial−mesenchymal transformation (EMT). The aim of this study was to compare levels of ZEB1 and ZEB2 in the peritoneal fluid and plasma between patients with and without endometriosis in order to assess their utility in the diagnostic process. Plasma and peritoneal fluid samples were collected from 50 patients with and 48 without endometriosis during planned surgical procedures in eight clinical centers. Quantitative ZEB1 and ZEB2 levels analyses were performed using a double-antibody sandwich enzyme-linked immunosorbent assay (ELISA). No significant differences were observed in ZEB1 levels in any of the subanalyses nor any differences regarding ZEB2 levels between patients with and without endometriosis. Plasma ZEB2 levels were significantly higher among patients with infertility compared to fertile women (16.07 ± 12.70 ng/L vs. 12.07 ± 11.92 ng/L; p < 0.04). Both ZEB1 and ZEB2 do not seem to have a significant value in the initial diagnosis of endometriosis as a single marker. The differences in ZEB2 plasma levels between patients with and without infertility indicate the possibility of EMT dysregulation in the pathogenesis of adverse fertility outcomes.

The role of interleukin-33 in organ fibrosis

Interleukin (IL)-33 is highly expressed in the nucleus of cells present at barrier sites and signals via the ST2 receptor. IL-33 signalling via ST2 is essential for return to tissue homeostasis after acute inflammation, promoting fibrinogenesis and wound healing at injury sites. However, this wound-healing response becomes aberrant during chronic or sustained inflammation, leading to transforming growth factor beta (TGF-β) release, excessive extracellular matrix deposition, and fibrosis. This review addresses the role of the IL-33 pathway in fibrotic diseases of the lung, liver, gastrointestinal tract, skin, kidney and heart. In the lung and liver, IL-33 release leads to the activation of pro-fibrotic TGF-β, and in these sites, IL-33 has clear pro-fibrotic roles. In the gastrointestinal tract, skin, and kidney, the role of IL-33 is more complex, being both pro-fibrotic and tissue protective. Finally, in the heart, IL-33 serves cardioprotective functions by favouring tissue healing and preventing cardiomyocyte death. Altogether, this review indicates the presence of an unclear and delicate balance between resolving and pro-fibrotic capabilities of IL-33, which has a central role in the modulation of type 2 inflammation and fibrosis in response to tissue injury.

Is Epithelial-Mesenchymal Transition a New Roadway in the Pathogenesis of Oral Submucous Fibrosis: A Comprehensive Review

Epithelial-mesenchymal transition (EMT) collectively refers to a series of episodes that reshape polarized, intact epithelial cells into discrete motile cells that can conquer the extracellular matrix (ECM). It performs a pivotal role in embryonic development, wound healing, and tissue repair. Surprisingly, the exact mechanism can also lead to the onset of malignancy and organ fibrosis contributing to scar formation and loss of function. transforming growth factor signaling, WNT signaling, Notch signaling, Hedgehog signaling, and receptor tyrosine kinase signaling, as well as non-transcriptional changes in response to extracellular cues, such as growth factors and cytokines, hypoxia, and contact with the surrounding ECM, are responsible for the initiation of EMT.

Although the pathogenesis of oral submucous fibrosis (OSMF) is multifactorial, compelling evidence suggests that it results from collagen deregulation. EMT is one of the spotlight events in the pathogenesis of OSMF, with myofibroblasts and keratinocytes being the victim cells. EMT is an essential step in both physiological and pathological events. The importance of EMT in the malignant development of OSMF and the inflammatory reaction preceding fibrosis implies a new upcoming area of research.

This review aims to focus on the EMT events that function as a double-edged sword between wound healing and fibrosis and further discuss the mechanisms along with the molecular pathways that direct changes in gene expression essential for the same in the oral cavity. As OSMF involves a risk of malignant transformation, understanding the cellular and molecular events will open more avenues for therapeutic breakthroughs targeting EMT.

Elucidating the diversity of malignant mesenchymal states in glioblastoma by integrative analysis

Background

Multiple glioblastoma studies have described a mesenchymal (MES) state, with each study defining the MES program by distinct sets of genes and highlighting distinct functional associations, including both immune activation and suppression. These variable descriptions complicate our understanding of the MES state and its implications. Here, we hypothesize that there is a range of glioma MES states, possibly reflecting distinct prior states in which a MES program can be induced, and/or distinct mechanisms that induce the MES states in those cells.

Methods

We integrated multiple published single-cell and bulk RNA sequencing datasets and MES signatures to define a core MES program that recurs across studies, as well as multiple function-specific MES signatures that vary across MES cells. We then examined the co-occurrence of these signatures and their associations with genetic and microenvironmental features.

Results

Based on co-occurrence of MES signatures, we found three main variants of MES states: hypoxia-related (MES-Hyp), astrocyte-related (MES-Ast), and an intermediate state. Notably, the MES states are differentially associated with genetic and microenvironmental features. MES-Hyp is preferentially associated with NF1 deletion, overall macrophage abundance, a high macrophage/microglia ratio, and M2-related macrophages, consistent with previous studies that associated MES with immune suppression. In contrast, MES-Ast is associated with T cell abundance and cytotoxicity, consistent with immune activation through expression of MHC-I/II.

Conclusions

Diverse MES states occur in glioblastoma. These states share a subset of core genes but differ primarily in their association with hypoxia vs. astrocytic expression programs, and with immune suppression vs. activation, respectively.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13073-022-01109-8.

Reforming the Barrier: The Role of Formins in Wound Repair

The restoration of an intact epidermal barrier after wound injury is the culmination of a highly complex and exquisitely regulated physiological process involving multiple cells and tissues, overlapping dynamic events and protein synthesis and regulation. Central to this process is the cytoskeleton, a system of intracellular proteins that are instrumental in regulating important processes involved in wound repair including chemotaxis, cytokinesis, proliferation, migration, and phagocytosis. One highly conserved family of cytoskeletal proteins that are emerging as major regulators of actin and microtubule nucleation, polymerization, and stabilization are the formins. The formin family includes 15 different proteins categorized into seven subfamilies based on three formin homology domains (FH1, FH2, and FH3). The formins themselves are regulated in different ways including autoinhibition, activation, and localization by a range of proteins, including Rho GTPases. Herein, we describe the roles and effects of the formin family of cytoskeletal proteins on the fundamental process of wound healing and highlight recent advances relating to their important functions, mechanisms, and regulation at the molecular and cellular levels.

Similarities between wound re-epithelialization and Metastasis in ESCC and the crucial involvement of macrophages: A review

In cancer, tumor-associated macrophages (TAMs) possess crucial functions in facilitating epithelial-mesenchymal transition (EMT). EMT is a crucial process in tumor metastasis. Tumor metastasis is one of the hallmarks of cancer and leads to patient mortality. Cancer cells often find ways to evade being detected and attacked by the immune system. This is achieved by cross-talk between cancer cells and the altered microenvironment. The accumulation of tumor-associated macrophages (TAMs) in the tumor microenvironment (TME) creates an immunosuppressive and tumor-supportive environment. Circulating monocytes and macrophages which are recruited into tumors are defined as tumor-associated macrophages once in the TME. Based on the activated stimuli and function, macrophages can be divided into M1 macrophages and M2 macrophages. M1 macrophages, also known as classically activated macrophages, exhibit pro-inflammatory and antitumor activities. M2 macrophages, also known as alternatively activated macrophages, exhibit anti-inflammatory, pro-tumorigenic, and wound healing activities. TAMs are considered to be of the M2 phenotype. The TME polarizes recruited macrophages into M2 macrophages as they provide an immunosuppressive pro-tumoral environment. Accumulating studies show that the presence of TAMs in esophageal squamous cell carcinoma (ESCC) leads to tumor progression. In this review, we discuss how EMT can be used by TAMs to cause tumor migration and metastasis in ESCC. We also discuss the potential therapies targeting TAMs.

Loss of MEN1 leads to renal fibrosis and decreases HGF-Adamts5 pathway activity via an epigenetic mechanism

BACKGROUND

Renal fibrosis is a serious condition that results in the development of chronic kidney diseases. The MEN1 gene is an epigenetic regulator that encodes the menin protein and its role in kidney tissue remains unclear.

METHODS

Kidney histology was examined on paraffin sections stained with hematoxylin-eosin staining. Masson's trichrome staining and Sirius red staining were used to analyze renal fibrosis. Gene and protein expression were determined by quantitative real-time PCR (qPCR) and Western blot, respectively. Immunohistochemistry staining in the kidney tissues from mice or patients was used to evaluate protein levels. Flow cytometry was used to analyze the cell cycle distributions and apoptosis. RNA-sequencing was performed for differential expression genes in the kidney tissues of the Men1f/f and Men1∆/∆ mice. Chromatin immunoprecipitation sequencing (ChIP-seq) was carried out for identification of menin- and H3K4me3-enriched regions within the whole genome in the mouse kidney tissue. ChIP-qPCR assays were performed for occupancy of menin and H3K4me3 at the gene promoter regions. Luciferase reporter assay was used to detect the promoter activity. The exacerbated unilateral ureteral obstruction (UUO) models in the Men1f/f and Men1∆/∆ mice were used to assess the pharmacological effects of rh-HGF on renal fibrosis.

RESULTS

The expression of MEN1 is reduce in kidney tissues of fibrotic mouse and human diabetic patients and treatment with fibrotic factor results in the downregulation of MEN1 expression in renal tubular epithelial cells (RTECs). Disruption of MEN1 in RTECs leads to high expression of α-SMA and Collagen 1, whereas MEN1 overexpression restrains epithelial-to-mesenchymal transition (EMT) induced by TGF-β treatment. Conditional knockout of MEN1 resulted in chronic renal fibrosis and UUO-induced tubulointerstitial fibrosis (TIF), which is associated with an increased induction of EMT, G2/M arrest and JNK signaling. Mechanistically, menin recruits and increases H3K4me3 at the promoter regions of hepatocyte growth factor (HGF) and a disintegrin and metalloproteinase with thrombospondin motifs 5 (Adamts5) genes and enhances their transcriptional activation. In the UUO mice model, exogenous HGF restored the expression of Adamts5 and ameliorated renal fibrosis induced by Men1 deficiency.

CONCLUSIONS

These findings demonstrate that MEN1 is an essential antifibrotic factor in renal fibrogenesis and could be a potential target for antifibrotic therapy.

Metastasis prevention: targeting causes and roots

The spread of tumor cells from the primary focus, metastasis, is the main cause of cancer mortality. Therefore, anticancer therapy should be focused on the prevention of metastatic disease. Key targets can be conditions in the primary tumor that are favorable for the appearance of metastatic cells and the first steps of the metastatic cascade. Here, we discuss different approaches for targeting metastasis causes (hypoxia, metabolism changes, and tumor microenvironment) and roots (angiogenesis, epithelial-mesenchymal transition, migration, and invasion). Also, we emphasize the challenges of the existing approaches for metastasis prevention and suggest opportunities to overcome them. In conclusion, we highlight the importance of clinical evaluation of the agents showing antimetastatic effects in vivo, especially in patients with early-stage cancers, the identification of metastatic seeds, and the development of therapeutics for their eradication.

Epithelial-to-Mesenchymal Transition Signaling Pathways Responsible for Breast Cancer Metastasis

Breast carcinoma is highly metastatic and invasive. Tumor metastasis is a convoluted and multistep process involving tumor cell disseminating from their primary site and migrating to the secondary organ. Epithelial-mesenchymal transition (EMT) is one of the crucial steps that initiate cell progression, invasion, and metastasis. During EMT, epithelial cells alter their molecular features and acquire a mesenchymal phenotype. The regulation of EMT is centered by several signaling pathways, including primary mediators TGF-β, Notch, Wnt, TNF-α, Hedgehog, and RTKs. It is also affected by hypoxia and microRNAs (miRNAs). All these pathways are the convergence on the transcriptional factors such as Snail, Slug, Twist, and ZEB1/2. In addition, a line of evidence suggested that EMT and cancer stem like cells (CSCs) are associated. EMT associated cancer stem cells display mesenchymal phenotypes and resist to chemotherapy or targeted therapy. In this review, we highlighted recent discoveries in these signaling pathways and their regulation in breast cancer metastasis and invasion. While the clinical relevance of EMT and breast cancers remains controversial, we speculated a convergent signaling network pivotal to elucidating the transition of epithelial to mesenchymal phenotypes and onset of metastasis of breast cancer cells.

Bitter taste receptors protect against skin aging by inhibiting cellular senescence and enhancing wound healing

BACKGROUND/OBJECTIVES

Bitter taste receptors are taste signaling pathway mediators, and are also expressed and function in extra-gustatory organs. Skin aging affects the quality of life and may lead to medical issues. The purpose of this study was to better understand the anti-skin aging effects of bitter taste receptors in D-galactose (D-gal)-induced aged human keratinocytes, HaCaT cells.

MATERIALS/METHODS

Expressions of bitter taste receptors in HaCaT cells and mouse skin tissues were examined by polymerase chain reaction assay. Bitter taste receptor was overexpressed in HaCaT cells, and D-gal was treated to induce aging. We examined the effects of bitter taste receptors on aging by using β-galactosidase assay, wound healing assay, and Western blot assay.

RESULTS

TAS2R16 and TAS2R10 were expressed in HaCaT cells and were upregulated by D-gal treatment. TAS2R16 exerted protective effects against skin aging by regulating p53 and p21, antioxidant enzymes, the SIRT1/mechanistic target of rapamycin pathway, cell migration, and epithelial-mesenchymal transition markers. TAS2R10 was further examined to confirm a role of TAS2R16 in cellular senescence and wound healing in D-gal-induced aged HaCaT cells.

CONCLUSIONS

Our results suggest a novel potential preventive role of these receptors on skin aging by regulating cellular senescence and wound healing in human keratinocyte, HaCaT.

Can We Predict Differentiated Thyroid Cancer Behavior? Role of Genetic and Molecular Markers

Thyroid cancer is ranked in ninth place among all the newly diagnosed cancer cases in 2020. Differentiated thyroid cancer behavior can vary from indolent to extremely aggressive. Currently, predictions of cancer prognosis are mainly based on clinicopathological features, which are direct consequences of cell and tissue microenvironment alterations. These alterations include genetic changes, cell cycle disorders, estrogen receptor expression abnormalities, enhanced epithelial-mesenchymal transition, extracellular matrix degradation, increased hypoxia, and consecutive neovascularization. All these processes are represented by specific genetic and molecular markers, which can further predict thyroid cancer development, progression, and prognosis. In conclusion, evaluation of cancer genetic and molecular patterns, in addition to clinicopathological features, can contribute to the identification of patients with a potentially worse prognosis. It is essential since it plays a crucial role in decision-making regarding initial surgery, postoperative treatment, and follow-up. To date, there is a large diversity in methodologies used in different studies, frequently leading to contradictory results. To evaluate the true significance of predictive markers, more comparable studies should be conducted.

In vitro antioxidant and wound healing properties of baru nut extract (Dipteryx alata Vog.) in pulmonary epithelial cells for therapeutic application in chronic pulmonary obstructive disease (COPD)

Baru nuts (Dipteryx alata Vog.) are a native species from Brazil, rich in phenols and other antioxidants, with high socioeconomic value and possible pharmaceutical applications. Here we investigated baru nut ethanolic extract (BNEE) antioxidant and wound healing activities in human NCI-H441 and A549 lung epithelial cell lines for a possible use in conditions related to oxidative stress and wound healing impairments, such as chronic obstructive pulmonary disease (COPD). BNEE was characterised with high DPPH free radical scavenging activity and high total phenolics content, amongst them gallic acid, that was identified and quantified by HPLC. BNEE was not cytotoxic at concentrations studied, reduced the levels of reactive oxygen species before and during oxidative stress and increased wound healing in cell monolayers. These are the first steps to investigate the beneficial properties of baru in diseases related to oxidative stress and wound healing impairments such as COPD.

The Genomic Processes of Biological Invasions: From Invasive Species to Cancer Metastases and Back Again

The concept of invasion is useful across a broad range of contexts, spanning from the fine scale landscape of cancer tumors up to the broader landscape of ecosystems. Invasion biology provides extraordinary opportunities for studying the mechanistic basis of contemporary evolution at the molecular level. Although the field of invasion genetics was established in ecology and evolution more than 50 years ago, there is still a limited understanding of how genomic level processes translate into invasive phenotypes across different taxa in response to complex environmental conditions. This is largely because the study of most invasive species is limited by information about complex genome level processes. We lack good reference genomes for most species. Rigorous studies to examine genomic processes are generally too costly. On the contrary, cancer studies are fortified with extensive resources for studying genome level dynamics and the interactions among genetic and non-genetic mechanisms. Extensive analysis of primary tumors and metastatic samples have revealed the importance of several genomic mechanisms including higher mutation rates, specific types of mutations, aneuploidy or whole genome doubling and non-genetic effects. Metastatic sites can be directly compared to primary tumor cell counterparts. At the same time, clonal dynamics shape the genomics and evolution of metastatic cancers. Clonal diversity varies by cancer type, and the tumors’ donor and recipient tissues. Still, the cancer research community has been unable to identify any common events that provide a universal predictor of “metastatic potential” which parallels findings in evolutionary ecology. Instead, invasion in cancer studies depends strongly on context, including order of events and clonal composition. The detailed studies of the behavior of a variety of human cancers promises to inform our understanding of genome level dynamics in the diversity of invasive species and provide novel insights for management.

Unraveling the roles of miRNAs in regulating epithelial-to-mesenchymal transition (EMT) in osteosarcoma

Osteosarcoma is one of the most prevalent primary bone tumors with a high metastatic and recurrence rate with poor prognosis. MiRNAs are short and non-coding RNAs that could regulate various cellular activities and one of them is the epithelial-to-mesenchymal transition (EMT). Osteosarcoma cells that have undergone EMT would lose their cellular polarity and acquire invasive and metastatic characteristics. Our literature search showed that many pre-clinical and clinical studies have reported the roles of miRNAs in modulating the EMT process in osteosarcoma and compared to other cancers like breast cancer, there is a lack of review article which effectively summarizes the various roles of EMT-regulating miRNAs in osteosarcoma. This review, therefore, was aimed to discuss and summarize the EMT-promoting and EMT-suppressing roles of different miRNAs in osteosarcoma. The review would begin with the discussion on the concepts and principles of EMT, followed by the exploration of the diverse roles of EMT-regulating miRNAs in osteosarcoma. Subsequently, the potential use of miRNAs as prognostic biomarkers in osteosarcoma to predict the likelihood of metastases and as therapeutic agents would be discussed.

Epithelial-Mesenchymal Transition (EMT): The Type-2 EMT in Wound Healing, Tissue Regeneration and Organ Fibrosis

The epithelial–mesenchymal transition (EMT) is an essential event during cell development, in which epithelial cells acquire mesenchymal fibroblast-like features including reduced intercellular adhesion and increased motility. EMT also plays a key role in wound healing processes, which are mediated by inflammatory cells and fibroblasts. These cells secrete specific factors that interact with molecules of the extracellular matrix (ECM) such as collagens, laminins, elastin and tenascins. Wound healing follows four distinct and successive phases characterized by haemostasis, inflammation, cell proliferation and finally tissue remodeling. EMT is classified into three diverse subtypes: type-1 EMT, type-2 EMT and type-3 EMT. Type-1 EMT is involved in embryogenesis and organ development. Type-2 EMT is associated with wound healing, tissue regeneration and organ fibrosis. During organ fibrosis, type-2 EMT occurs as a reparative-associated process in response to ongoing inflammation and eventually leads to organ destruction. Type-3 EMT is implicated in cancer progression, which is linked to the occurrence of genetic and epigenetic alterations, in detail the ones promoting clonal outgrowth and the formation of localized tumors. The current review aimed at exploring the role of EMT process with particular focus on type-2 EMT in wound healing, fibrosis and tissue regeneration, as well as some recent progresses in the EMT and tissue regeneration field, including the modulation of EMT by biomaterials.

Induction of the epithelial-mesenchymal transition in the endometrium by chronic endometritis in infertile patients

Background

The purpose of the present study was to evaluate the relationship between chronic endometritis and the epithelial-mesenchymal transition in the endometrium of infertile patients in the implantation phase.

Methods

Endometrial biopsy specimens from 66 infertility patients were analyzed. The presence of chronic endometritis was investigated by immunostaining for CD138. Immunohistochemical staining for E-cadherin, N-cadherin, Slug, and Snail was performed, and the expression profiles were statistically analyzed according to the presence of chronic endometritis. When the loss of E-cadherin expression and/or the positive expression of N-cadherin was detected, the specimen was considered epithelial-mesenchymal transition-positive. Epithelial-mesenchymal transition-positive cases were also statistically analyzed according to the presence of chronic endometritis. The characteristics of the patients in the epithelial-mesenchymal transition-positive and epithelial-mesenchymal transition-negative groups were compared. The association between variables, including age, body mass index, gravidity, parity, and each causative factor of infertility and epithelial-mesenchymal transition positivity was analyzed.

Results

The rates of the loss of E-cadherin expression, the gain of N-cadherin and epithelial-mesenchymal transition positivity were significantly higher in chronic endometritis patients. The expression of Slug, cytoplasmic Snail, and nuclear Snail was also detected at significantly higher rates in chronic endometritis patients. Chronic endometritis were related to the epithelial-mesenchymal transition.

Conclusion

The epithelial-mesenchymal transition was frequently detected in the endometrium in infertile patients with chronic endometritis. Since the epithelial-mesenchymal transition is associated with chronic endometritis, the epithelial-mesenchymal transition appears to be involved in the alteration of mechanisms of implantation.

Quantitative Proteomic Analysis in Alveolar Type II Cells Reveals the Different Capacities of RAS and TGF-β to Induce Epithelial-Mesenchymal Transition

Alveolar type II (ATII) epithelial cells function as stem cells, contributing to alveolar renewal, repair and cancer. Therefore, they are a highly relevant model for studying a number of lung diseases, including acute injury, fibrosis and cancer, in which signals transduced by RAS and transforming growth factor (TGF)-β play critical roles. To identify downstream molecular events following RAS and/or TGF-β activation, we performed proteomic analysis using a quantitative label-free approach (LC-HDMS^E) to provide in-depth proteome coverage and estimates of protein concentration in absolute amounts. Data are available via ProteomeXchange with identifier PXD023720. We chose ATII^ER:KRASV12 as an experimental cell line in which RAS is activated by adding 4-hydroxytamoxifen (4-OHT). Proteomic analysis of ATII cells treated with 4-OHT or TGF-β demonstrated that RAS activation induces an epithelial–mesenchymal transition (EMT) signature. In contrast, under the same conditions, activation of TGF-β signaling alone only induces a partial EMT. EMT is a dynamic and reversible biological process by which epithelial cells lose their cell polarity and down-regulate cadherin-mediated cell–cell adhesion to gain migratory properties, and is involved in embryonic development, wound healing, fibrosis and cancer metastasis. Thus, these results could help to focus research on the identification of processes that are potentially driving EMT-related human disease.

Neuronal innervation of the intestinal crypt

Mucosal damage is a key feature of inflammatory bowel diseases (IBD) and healing of the mucosa is an endpoint of IBD treatment that is often difficult to achieve. Autonomic neurons of the parasympathetic and sympathetic nervous system may influence intestinal epithelial cell growth and modulating epithelial innervation could for that reason serve as an interesting therapeutic option to improve mucosal healing. Understanding of the biological processes triggered by nonspecific and specific epithelial adrenergic and cholinergic receptor activation is of key importance. At present, with rising technological advances, bioelectronic neuromodulation as treatment modality has gained momentum. We discuss the current view on state-of-the-art innervation of the intestinal crypt and its impact on epithelial cell growth and differentiation. Furthermore, we outline bioelectronic technology and review its relevance to wound healing processes.

Methods to Generate Tube Micropatterns for Epithelial Morphogenetic Analyses and Tissue Engineering

Cells live in a highly curved and folded 3D microenvironment within the human body. Since epithelial cells in internal organs usually adopt a tubular shape, there is a need to engineer simple in vitro devices to promote this cellular configuration. The aim of these devices would be to investigate epithelial morphogenesis and cell behavior-leading to the development of more sophisticated platforms for tissue engineering and regenerative medicine. In this chapter, we first explain the need for such epithelial tubular micropatterns based on anatomical considerations and then survey methods that can be used to study different aspects of epithelial tubulogenesis. The methods examined can broadly be divided into two classes: conventional 2D microfabrication for the formation of simple epithelial tubes in substrates of different stiffness; and 3D approaches to enable the self-assembly of organoid-derived epithelial tubes in a tubular configuration. These methods demonstrate that modeling tubulogenesis in vitro with high resolution, accuracy, and reproducibility is possible.

Resistance to paclitaxel induces glycophenotype changes and mesenchymal-to-epithelial transition activation in the human prostate cancer cell line PC-3

The development of the multidrug resistance phenotype is one of the major challenges faced in the treatment of cancer. The multidrug resistance phenotype is characterized by cross-resistance to drugs with different chemical structures and mechanisms of action. In this work, we hypothesized that the acquisition of resistance in cancer is accompanied by activation of the epithelial-to-mesenchymal transition process, where the tumor cell acquires a more mobile and invasive phenotype; a fundamental step in tumor progression and in promoting the invasion of other organs and tissues. In addition, it is known that atypical glycosylations are characteristic of tumor cells, being used as biomarkers. We believe that the acquisition of the multidrug resistance phenotype and the activation of epithelial-to-mesenchymal transition provoke alterations in the cell glycophenotype, which can be used as glycomarkers for chemoresistance and epithelial-to-mesenchymal transition processes. Herein, we induced the multidrug resistance phenotype in the PC-3 human prostate adenocarcinoma line through the continuous treatment with the drug paclitaxel. Our results showed that the induced cell multidrug resistance phenotype (1) acquired a mixed profile between epithelial and mesenchymal phenotypes and (2) modified the glycophenotype, showing an increase in the level of sialylation and in the number of branched glycans. Both mechanisms are described as indicators of poor prognosis.

All Trans Retinoic Acid (ATRA) progresses alveolar epithelium regeneration by involving diverse signalling pathways in emphysematous rat

INTRODUCTION

Pulmonary emphysema is characterized by destruction of alveoli leading to inadequate oxygenation, disability and frequently death. This destruction was understood so far as irreversible. Published data has shown that ATRA (All Trans Retinoic Acid) reverses elastase-induced emphysema in rats. However, the molecular mechanisms governing regeneration process are so far unknown.

OBJECTIVE

To examine the therapeutic potential of ATRA on various molecular pathways and their coordination towards governance of alveolar epithelial regeneration in emphysematous rats.

METHODS

Emphysema was induced by elastase versus saline in Sprague-Dawley rats. On days 26-37, rats received daily intraperitoneal injections with ATRA (500 μg/kg b.w.) versus olive-oil. Lungs were removed at day 38 for histopathology and investigation of relative mRNA and protein expressions.

RESULTS

Histopathological analysis has shown that losses of alveoli were recovered in therapy (EA) group. Moreover, expressions of markers genes for alveolar cell proliferation, differentiation and EMT events at mRNA and protein levels were significantly increased in EA group than emphysema group (ES). Upon validation at genomics level, expressions of components of Notch, Hedgehog, Wnt, BMP and TGFβ pathways were significantly attenuated in EA group when compared with ES and were well comparable with the healthy group.

CONCLUSION

Therapeutic supplementation of ATRA rectifies the deregulated Notch, Hedgehog, Wnt, BMP and TGFβ pathways in emphysema condition, resulting in alveolar epithelium regeneration. Hence, ATRA may prove to be a potential drug in the treatment of emphysema. Nevertheless, elaborated studies are to be conducted.

TRANSICIÓN EPITELIO-MESÉNQUIMA INDUCIDA POR VIRUS

La Transición Epitelio-Mesénquima (EMT) es un proceso de dediferenciación altamente conservado en vertebrados. Este ocurre en células epiteliales con la activación progresiva de la pérdida de la polaridad, la adquisición de motilidad individual y la capacidad invasiva a otros tejidos. La EMT es un proceso normal durante el desarrollo; no obstante, en condiciones patológicas está relacionada con la inducción de metástasis, lo cual representa una vía alterna al desarrollo de procesos oncogénicos tempranos. Aunque la EMT es activada principalmente por factores de crecimiento, también se puede desencadenar por infecciones de patógenos intracelulares mediante la activación de rutas moleculares inductoras de este proceso. Por lo tanto, una infección bacteriana o viral pueda generar predisposición al desarrollo de tumores. Nuestro interés está enfocado principalmente encaracterizar la relación virus-hospedero, y en el caso de los virus, varios ya se han descrito como inductores de la EMT. En este artículo de revisión se describenelfenómeno de la plasticidad celular y la ocurrencia detallada del proceso de EMT, los patógenos virales reportados como inductores, los mecanismos moleculares usados para ello y las vías de regulación mediante miRNAs. Por último, se discute cómo esta relación virus-hospedero puede explicar la patogénesis de la enfermedad causada por Dengue virus, favoreciendo la identificación de blancos moleculares para terapia, estrategia conocida como Antivirales dirigidos a blancos celulares o HTA (Host-targeting antivirals).

Biotech-Educated Platelets: Beyond Tissue Regeneration 2.0

The increasing discoveries regarding the biology and functions of platelets in the last decade undoubtedly show that these cells are one of the most biotechnological human cells. This review summarizes new advances in platelet biology, functions, and new concepts of biotech-educated platelets that connect advanced biomimetic science to platelet-based additive manufacturing for tissue regeneration. As highly responsive and secretory cells, platelets could be explored to develop solutions that alter injured microenvironments through platelet-based synthetic biomaterials with instructive extracellular cues for morphogenesis in tissue engineering beyond tissue regeneration 2.0.

The Protective Effect of Antioxidants in Areca Nut Extract-Induced Oral Carcinogenesis

Objective:

Oral submucous fibrosis (OSF) is the premalignant disorder associated with fibrosis and epithelial atrophy. Areca Nut (AN) is the most significant risk factors for OSF. However, the molecular mechanism behind AN induced OSF remains unclear, and there exists no effective treatment for the malignant disorder. We aimed to investigate whether AN-extract causes epithelial-mesenchymal transition (EMT) in oral keratinocytes, and evaluated the therapeutic potential of antioxidants.

Methods:

The HPV16 E6/E7-transfected immortalized human oral keratinocytes (IHOK) were employed in the present study. For the preparation of AN-extract, dried AN was dissolved in distilled water overnight. The solution was centrifuged and the supernatant was collected for further use. For the determination of change in cytokine levels, ELISA was performed. To investigate EMT-related protein expression and phenotype, immunoblot and immunofluorescence were performed.

Results:

Among tumor-promoting cytokines (Gro-α, IL-6 and IL-8), IL-6 was remarkably increased by AN in IHOK. AN-extract induced EMT phenotypes, such as cell elongation, up-regulation of vimentin and snail. After treatment with neutralizing antibody of IL-6, AN-induced snail expression was reduced remarkably. Collectively, AN-extract induced IL-6 expression and mediated EMT. The use of antioxidants (EGCG, glutathione and NAC) significantly reduced IL-6 expression in AN-treated IHOK. Also, AN-decreased E-cadherin and increased vimentin were reversed by antioxidants, indicating that the effectiveness of antioxidants in inhibiting IL-6-induced EMT by AN.

Conclusion:

AN promotes EMT and antioxidants interrupt AN-induced-EMT in oral keratinocytes. Consequently, it is proposed that antioxidants could prevent AN-induced carcinogenesis and function as a prototype for developing therapeutic interventions of OSF.

Anti-Cancer Activity of Acriflavine as Metabolic Inhibitor of OXPHOS in Pancreas Cancer Xenografts

Purpose

All currently available therapies for the treatment of pancreatic ductal adenocarcinoma (PDAC) show limited success. PDACs fast progression depends on the tumor characteristics and can be influenced by the microenvironment. The antibacterial drug acriflavine (ACF) has been shown to have anti-cancer activities in cell lines.

Materials and Methods

To understand the working mechanism of ACF on cancer progression and tumor-stromal interplay, we evaluated pancreatic cancer in cell culture (Panc-1) (morphology, cell invasion and RNA expression) and the macrophage cell line THP1 (representing innate immune stromal cells). In the translational arm, the activity of ACF on xenograft models of human PDAC tumors representing different clinical subclasses was investigated (tumor growth, morphology and immunofluorescence, RNA expression and pathway analysis).

Results

In vitro, ACF reduces epithelial-to-mesenchymal transition (EMT) and invasion of Panc-1 cells and shifts macrophage polarization to a M1-like anti-tumoral phenotype. At non-toxic concentrations, ACF downregulates cell metabolism. In xenografts, effect on tumor growth and metabolism could be confirmed; however, the innate immune stromal cells did not respond. Importantly, only in the moderately differentiated PDAC model, ACF could significantly suppress tumor growth and not in the fast-growing EMT-high model. Pathway analysis shows that ACF highly significantly downregulates metabolic pathways, especially OXPHOS and MYC/cell proliferation pathways in xenografts.

Conclusion

ACF, with known pleiotropic effects on cancer cells, is in this study shown to be an attractive therapeutic based on its novel observed metabolic activity. Repurposing this compound for cancer treatment should be in the setting with other targeting agents, which offers reduced chance of resistance development in PDAC. Further evaluation should best be done in biological complex models such as human xenografts or syngeneic cancer models.

Dichloroacetate prevents TGFβ-induced epithelial-mesenchymal transition of retinal pigment epithelial cells

Proliferative retinopathies are associated with formation of fibrous epiretinal membranes. At present, there is no pharmacological intervention for the treatment of retinopathies. Cytokines such as TGFβ are elevated in the vitreous humor of the patients with proliferative vitro-retinopathy, diabetic retinopathy and age-related macular degeneration. TGFβ isoforms lead to epithelial-mesenchymal transition (EMT) or trans-differentiation of the retinal pigment epithelial (RPE) cells. PI3K/Akt and MAPK/Erk pathways play important roles in the EMT of RPE cells. Therefore, inhibition of EMT by pharmacological agents is an important therapeutic strategy in retinopathy. Dichloroacetate (DCA) is shown to prevent proliferation and EMT of cancer cell lines but its effects are not explored on the prevention of EMT of RPE cells. In the present study, we have investigated the role of DCA in preventing TGFβ2 induced EMT of RPE cell line, ARPE-19. A wound-healing assay was utilized to detect the anti-EMT effect of DCA. The expressions of EMT and cell adhesion markers were carried out by immunofluorescence, western blotting, and quantitative real-time PCR. The expression of MAPK/Erk and PI3K/Akt pathway members was carried out using western blotting. We found that TGFβ2 exposure leads to an increase in the wound healing response, expression of EMT markers (Fibronectin, Collagen I, N-cadherin, MMP9, S100A4, α-SMA, Snai1, Slug) and a decrease in the expression of cell adhesion/epithelial markers (ZO-1, Connexin 43, E-cadherin). These changes were accompanied by the activation of PI3K/Akt and MAPK/Erk pathways. Simultaneous exposure of DCA along with TGFβ2 significantly inhibited wound healing response, expression of EMT markers and cell adhesion/epithelial markers. Furthermore, DCA and TGFβ2 effectively attenuated the activation of MAPK/Erk/JNK and PI3K/Akt/GSK3β pathways. Our results demonstrate that DCA has a strong anti-EMT effect on the ARPE-19 cells and hence can be utilized as a therapeutic agent in the prevention of proliferative retinopathies.

Effects of human umbilical cord mesenchymal stem cells derived from exosomes on migration ability of endometrial glandular epithelial cells

The present study aimed to investigate the effects of human umbilical cord mesenchymal stem cells (Huc‑MSCs)‑derived exosomes on the migratory abilities of endometrial glandular epithelial cells, and to evaluate the underlying mechanism from the perspective of epithelial‑mesenchymal transition (EMT). Huc‑MSCs were prepared from human umbilical cord, and eutopic endometrial glandular epithelial cells were isolated from patients with endometriosis. The exosomes derived from Huc‑MSCs (Huc‑MSCs‑exo) were prepared using an exosome extraction kit. The endometrial glandular epithelial cells were randomly divided into two groups: Huc‑MSCs‑exo and control. Cell migratory ability was assessed and western blotting was used to detect the expression levels of EMT. The results of the present study demonstrated that Huc‑MSCs‑exo treatment significantly enhanced the migration of endometrial glandular epithelial cells from patients with endometriosis (P<0.05). The present study also demonstrated that treatment with Huc‑MSCs‑exo inhibited the expression levels of E‑cadherin and promoted the expression levels of Vimentin and N‑cadherin at both the mRNA and protein level. The results of the current study indicate that Huc‑MSCs‑exo enhance the migratory ability of endometrial glandular epithelial cells via promotion of EMT.

The Role of Epithelial-to-Mesenchymal Transition in Cutaneous Squamous Cell Carcinoma : Epithelial-to-Mesenchymal Transition in Cutaneous SCC

OPINION STATEMENT

The capacity of cells to modify their phenotypes from epithelial to mesenchymal (epithelial-to-mesenchymal transition or EMT) and vice versa provides them with a dynamic plasticity essential for human life, from embryogenesis to wound healing. Current knowledge about carcinogenetic mechanisms leaves little doubts on the pivotal participation of these interchangeable processes in cancer development, and their influence has been quite clearly established in the progression of cutaneous squamous cell carcinoma. A complex and ordered interplay of signals induces the shift between both phenotypes, providing cells with the most suitable state at every moment to face the next step in tumor invasion and dissemination. Some stimulatory triggers have opposite effects according to the biological context and in many cases exert collateral functions. This scenario makes finding an ideal therapeutic target difficult but provides the opportunity to intervene simultaneously at many different levels with small actions such as targeting the tumor environment. In any case, advances in knowledge of the EMT mechanisms and their influence on carcinogenesis and drug resistance will greatly influence the therapeutic strategies for many human tumors, including cutaneous squamous cell carcinoma.