Loss of TAK1 increases cell traction force in a ROS-dependent manner to drive epithelial-mesenchymal transition of cancer cells

YWHAG Deficiency Disrupts the EMT-Associated Network to Induce Oxidative Cell Death and Prevent Metastasis

Metastasis involves epithelial-to-mesenchymal transition (EMT), a process that is regulated by complex gene networks, where their deliberate disruption may yield a promising outcome. However, little is known about mechanisms that coordinate these metastasis-associated networks. To address this gap, hub genes with broad engagement across various human cancers by analyzing the transcriptomes of different cancer cell types undergoing EMT are identified. The oncogenic signaling adaptor protein tyrosine 3-monooxygenase/tryptophan 5-monooxygenase activation protein gamma (YWHAG) is ranked top for its clinical relevance and impact. The cellular kinome and transcriptome data are surveyed to construct the regulome of YWHAG, revealing stress responses and metabolic processes during cancer EMT. It is demonstrated that a YWHAG-dependent cytoprotective mechanism in the regulome is embedded in EMT-associated networks to protect cancer cells from oxidative catastrophe through enhanced autophagy during EMT. YWHAG deficiency results in a rapid accumulation of reactive oxygen species (ROS), delayed EMT, and cell death. Tumor allografts show that metastasis potential and overall survival time are correlated with the YWHAG expression level of cancer cell lines. Metastasized tumors have higher expression of YWHAG and autophagy-related genes than primary tumors. Silencing YWHAG diminishes primary tumor volumes, prevents metastasis, and prolongs the median survival period of the mice.

A tEMTing target? Clinical and experimental evidence for epithelial-mesenchymal transition in the progression of cutaneous squamous cell carcinoma (a scoping systematic review)

Cutaneous squamous cell carcinoma (cSCC) is a disease with globally rising incidence and poor prognosis for patients with advanced or metastatic disease. Epithelial-mesenchymal transition (EMT) is a driver of metastasis in many carcinomas, and cSCC is no exception. We aimed to provide a systematic overview of the clinical and experimental evidence for EMT in cSCC, with critical appraisal of type and quality of the methodology used. We then used this information as rationale for potential drug targets against advanced and metastatic cSCC. All primary literature encompassing clinical and cell-based or xenograft experimental studies reporting on the role of EMT markers or related signalling pathways in the progression of cSCC were considered. A screen of 3443 search results yielded 86 eligible studies comprising 44 experimental studies, 22 clinical studies, and 20 studies integrating both. From the clinical studies a timeline illustrating the alteration of EMT markers and related signalling was evident based on clinical progression of the disease. The experimental studies reveal connections of EMT with a multitude of factors such as genetic disorders, cancer-associated fibroblasts, and matrix remodelling via matrix metalloproteinases and urokinase plasminogen activator. Additionally, EMT was found to be closely tied to environmental factors as well as to stemness in cSCC via NFκB and β-catenin. We conclude that the canonical EGFR, canonical TGF-βR, PI3K/AKT and NFκB signalling are the four signalling pillars that induce EMT in cSCC and could be valuable therapeutic targets. Despite the complexity, EMT markers and pathways are desirable biomarkers and drug targets for the treatment of advanced or metastatic cSCC.

Profiling Glutathionylome in CD38-Mediated Epithelial-Mesenchymal Transition

Protein S-glutathionylation is an important posttranslational modification that regulates various cellular processes. However, changes in glutathionylome in epithelial-mesenchymal transition (EMT), a crucial cellular process for embryonic development, wound healing, and carcinoma progression and metastasis, have not been fully characterized. Our previous study revealed that CD38 overexpression decreased cellular nicotinamide adenine dinucleotide (NAD⁺) levels and caused cells to undergo EMT. In the present study, we engineered a cell system in which the glutathione synthetase (GS) mutant was expressed that catalyzed the formation of a glutathione analogue from azido-alanine to profile changes of glutathionylome in CD38-overexpressing cells. We identified 1298 glutathionylated proteins and revealed that proteins with changed glutathionylation levels involved in EMT associated pathways including epithelial adherens junction, actin cytoskeleton, and integrin signaling. Moreover, the glutathionylation level of 15-hydroxyprostaglandin dehydrogenase (15-PGDH) was increased in CD38-overexpressing cells. We further demonstrated that glutathionylation of Cys63 residue in 15-PGDH led to decreased enzymatic activity that could promote EMT by increasing prostaglandin E₂ (PGE₂). Taken together, these results indicate that the clickable glutathione is an effective probe for glutathionylome profiling, and glutathionylation of 15-PGDH on Cys63 inhibits its enzymatic activity to promote EMT.

Crosstalk Between ROS and Autophagy in Tumorigenesis: Understanding the Multifaceted Paradox

Cancer formation is a highly regulated and complex process, largely dependent on its microenvironment. This complexity highlights the need for developing novel target-based therapies depending on cancer phenotype and genotype. Autophagy, a catabolic process, removes damaged and defective cellular materials through lysosomes. It is activated in response to stress conditions such as nutrient deprivation, hypoxia, and oxidative stress. Oxidative stress is induced by excess reactive oxygen species (ROS) that are multifaceted molecules that drive several pathophysiological conditions, including cancer. Moreover, autophagy also plays a dual role, initially inhibiting tumor formation but promoting tumor progression during advanced stages. Mounting evidence has suggested an intricate crosstalk between autophagy and ROS where they can either suppress cancer formation or promote disease etiology. This review highlights the regulatory roles of autophagy and ROS from tumor induction to metastasis. We also discuss the therapeutic strategies that have been devised so far to combat cancer. Based on the review, we finally present some gap areas that could be targeted and may provide a basis for cancer suppression.

Redox signaling at the crossroads of human health and disease

Redox biology is at the core of life sciences, accompanied by the close correlation of redox processes with biological activities. Redox homeostasis is a prerequisite for human health, in which the physiological levels of nonradical reactive oxygen species (ROS) function as the primary second messengers to modulate physiological redox signaling by orchestrating multiple redox sensors. However, excessive ROS accumulation, termed oxidative stress (OS), leads to biomolecule damage and subsequent occurrence of various diseases such as type 2 diabetes, atherosclerosis, and cancer. Herein, starting with the evolution of redox biology, we reveal the roles of ROS as multifaceted physiological modulators to mediate redox signaling and sustain redox homeostasis. In addition, we also emphasize the detailed OS mechanisms involved in the initiation and development of several important diseases. ROS as a double‐edged sword in disease progression suggest two different therapeutic strategies to treat redox‐relevant diseases, in which targeting ROS sources and redox‐related effectors to manipulate redox homeostasis will largely promote precision medicine. Therefore, a comprehensive understanding of the redox signaling networks under physiological and pathological conditions will facilitate the development of redox medicine and benefit patients with redox‐relevant diseases.

Cross-Talk between Oxidative Stress and m6A RNA Methylation in Cancer

Oxidative stress is a state of imbalance between oxidation and antioxidation. Excessive ROS levels are an important factor in tumor development. Damage stimulation and excessive activation of oncogenes cause elevated ROS production in cancer, accompanied by an increase in the antioxidant capacity to retain redox homeostasis in tumor cells at an increased level. Although moderate concentrations of ROS produced in cancer cells contribute to maintaining cell survival and cancer progression, massive ROS accumulation can exert toxicity, leading to cancer cell death. RNA modification is a posttranscriptional control mechanism that regulates gene expression and RNA metabolism, and m⁶A RNA methylation is the most common type of RNA modification in eukaryotes. m⁶A modifications can modulate cellular ROS levels through different mechanisms. It is worth noting that ROS signaling also plays a regulatory role in m⁶A modifications. In this review, we concluded the effects of m⁶A modification and oxidative stress on tumor biological functions. In particular, we discuss the interplay between oxidative stress and m⁶A modifications.

Current Limitations and Candidate Potential of 5-HT7 Receptor Antagonism in Psychiatric Pharmacotherapy

Several mood-stabilizing atypical antipsychotics and antidepressants weakly block serotonin (5-HT) receptor type-7 (5-HT7R); however, the contributions of 5-HT7R antagonism to clinical efficacy and pathophysiology are yet to be clarified. A novel mood-stabilizing antipsychotic agent, lurasidone exhibits predominant binding affinity to 5-HT7R when compared with other monoamine receptors. To date, we have failed to discover the superior clinical efficacy of lurasidone on schizophrenia, mood, or anxiety disorders when compared with conventional mood-stabilizing atypical antipsychotics; however, numerous preclinical findings have indicated the possible potential of 5-HT7R antagonism against several neuropsychiatric disorders, as well as the generation of novel therapeutic options that could not be expected with conventional atypical antipsychotics. Traditional experimental techniques, electrophysiology, and microdialysis have demonstrated that the effects of 5-HT receptor type-1A (5-HT1AR) and 5-HT7R on neurotransmission are in contrast, but the effect of 5-HT1AR is more predominant than that of 5-HT7R, resulting in an insufficient understanding of the 5-HT7R function in the field of psychopharmacology. Accumulating knowledge regarding the pharmacodynamic profiles of 5-HT7R suggests that 5-HT7R is one of the key players in the establishment and remodeling of neural development and cytoarchitecture during the early developmental stage to the mature brain, and dysfunction or modulation of 5-HT7R is linked to the pathogenesis/pathophysiology of neuropsychiatric and neurodevelopmental disorders. In this review, to explore candidate novel applications for the treatment of several neuropsychiatric disorders, including mood disorders, schizophrenia, and other cognitive disturbance disorders, we discuss perspectives of psychopharmacology regarding the effects of 5-HT7R antagonism on transmission and intracellular signaling systems, based on preclinical findings.

The Role of Oxidative Stress and Its Counteractive Utility in Colorectal Cancer (CRC)

An altered redox status accompanied by an elevated generation of reactive oxygen/nitrogen species (ROS/RNS) has been implicated in a number of diseases including colorectal cancer (CRC). CRC, being one of the most common cancers worldwide, has been reported to be associated with multiple environmental and lifestyle factors (e.g., dietary habits, obesity, and physical inactivity) and harboring heightened oxidative stress that results in genomic instability. Although under normal condition ROS regulate many signal transduction pathways including cell proliferation and survival, overwhelming of the antioxidant capacity due to metabolic abnormalities and oncogenic signaling leads to a redox adaptation response that imparts drug resistance. Nevertheless, excessive reliance on elevated production of ROS makes the tumor cells increasingly vulnerable to further ROS insults, and the abolition of such drug resistance through redox perturbation could be instrumental to preferentially eliminate them. The goal of this review is to demonstrate the evidence that links redox stress to the development of CRC and assimilate the most up-to-date information that would facilitate future investigation on CRC-associated redox biology. Concomitantly, we argue that the exploitation of this distinct biochemical property of CRC cells might offer a fresh avenue to effectively eradicate these cells.

In Vivo Imaging with Genetically Encoded Redox Biosensors

Redox reactions are of high fundamental and practical interest since they are involved in both normal physiology and the pathogenesis of various diseases. However, this area of research has always been a relatively problematic field in the context of analytical approaches, mostly because of the unstable nature of the compounds that are measured. Genetically encoded sensors allow for the registration of highly reactive molecules in real-time mode and, therefore, they began a new era in redox biology. Their strongest points manifest most brightly in in vivo experiments and pave the way for the non-invasive investigation of biochemical pathways that proceed in organisms from different systematic groups. In the first part of the review, we briefly describe the redox sensors that were used in vivo as well as summarize the model systems to which they were applied. Next, we thoroughly discuss the biological results obtained in these studies in regard to animals, plants, as well as unicellular eukaryotes and prokaryotes. We hope that this work reflects the amazing power of this technology and can serve as a useful guide for biologists and chemists who work in the field of redox processes.

Multifaceted roles of TAK1 signaling in cancer

Context-specific signaling is a prevalent theme in cancer biology wherein individual molecules and pathways can have multiple or even opposite effects depending on the tumor type. TAK1 represents a particularly notable example of such signaling diversity in cancer progression. Originally discovered as a TGF-β-activated kinase, over the years it has been shown to respond to numerous other stimuli to phosphorylate a wide range of downstream targets and elicit distinct cellular responses across cell and tissue types. Here we present a comprehensive review of TAK1 signaling and provide important therapeutic perspectives related to its function in different cancers.

Epithelial-mesenchymal transition of cancer cells using bioengineered hybrid scaffold composed of hydrogel/3D-fibrous framework

Cancer cells undergoing epithelial-mesenchymal transition (EMT) acquire stem cell-like phenotype associated with malignant behaviour, chemoresistance, and relapse. Current two-dimensional (2D) in-vitro culture models of tumorigenesis are inadequate to replicate the complexity of in-vivo microenvironment. Therefore, the generation of functional three-dimensional (3D) constructs is a fundamental prerequisite to form multi-cellular tumour spheroids for studying basic pathological mechanisms. In this study, we focused on two major points (i) designing and fabrication of 3D hybrid scaffolds comprising electrospun fibers with cancer cells embedded within hydrogels, and (ii) determining the potential roles of 3D hybrid scaffolds associated with EMT in cancer progression and metastasis. Our findings revealed that 3D hybrid scaffold enhances cell proliferation and induces cancer cells to undergo EMT, as demonstrated by significant up-regulation of EMT associated transcriptional factors including Snail1, Zeb1, and Twist2; and mesenchymal markers whereas epithelial marker, E-Cadherin was downregulated. Remarkably, this induction is independent of cancer cell-type as similar results were obtained for breast cancer cells, MDA-MB-231 and gastric cancer cells, MKN74. Moreover, the hybrid scaffolds enrich aggressive cancer cells with stem cell properties. We showed that our 3D scaffolds could trigger EMT of cancer cells which could provide a useful model for studying anticancer therapeutics against metastasis.

Elevated level of mitochondrial reactive oxygen species via fatty acid β-oxidation in cancer stem cells promotes cancer metastasis by inducing epithelial-mesenchymal transition

Background

Cancer stem cells (CSCs) play a critical role in tumor development and progression and are involved in cancer metastasis. The role of reactive oxygen species (ROS) in CSCs and cancer metastasis remains controversial. The aim of the present study was to investigate the correlation between ROS level of CSCs and cancer metastasis and to explore the possible underlying molecular mechanisms.

Methods

Four different cell lines were used to isolate tumor spheres and to analyze intrinsic properties of tumor sphere cells including proliferation, self-renewal potential, differentiation, drug-resistance and cancer metastasis in vitro and in vivo. ROS assays were used to detect the intracellular ROS level of tumor spheres cells. Gene expression analysis and western blot were used to investigate the underlying mechanisms of ROS in regulating cancer metastasis.

Results

Tumor spheres possessed the characteristic features of CSCs, and ROS-high tumor spheres (RH-TS) displayed elevated mitochondrial ROS level exclusively drove metastasis formation. The gene expression analysis showed elevated fatty acid β-oxidation, downregulation of epithelial marker upregulation of mesenchymal markers, and the activation of MAP kinase cascades. Furthermore, 14 up-regulated genes in RH-TS cells were associated with reduced overall survival of different cancer patients.

Conclusions

Our findings demonstrate that CSCs characterized by elevated mitochondrial ROS level potentiate cancer metastasis. Mechanistically, elevated mitochondrial ROS via fatty acid β-oxidation, activates the MAPK cascades, resulting in the epithelial-mesenchymal transition (EMT) process of RH-TS cells, thereby potentiating caner invasion and metastasis. Therefore, targeting mitochondrial ROS might provide a promising approach to prevent and alleviate cancer metastasis induced by RH-TS cells.

Electronic supplementary material

The online version of this article (10.1186/s13287-019-1265-2) contains supplementary material, which is available to authorized users.

Antibody Treatment against Angiopoietin-Like 4 Reduces Pulmonary Edema and Injury in Secondary Pneumococcal Pneumonia

Secondary bacterial lung infection by Streptococcus pneumoniae (S. pneumoniae) poses a serious health concern, especially in developing countries. We posit that the emergence of multiantibiotic-resistant strains will jeopardize current treatments in these regions. Deaths arising from secondary infections are more often associated with acute lung injury, a common consequence of hypercytokinemia, than with the infection per se Given that secondary bacterial pneumonia often has a poor prognosis, newer approaches to improve treatment outcomes are urgently needed to reduce the high levels of morbidity and mortality. Using a sequential dual-infection mouse model of secondary bacterial lung infection, we show that host-directed therapy via immunoneutralization of the angiopoietin-like 4 c-isoform (cANGPTL4) reduced pulmonary edema and damage in infected mice. RNA sequencing analysis revealed that anti-cANGPTL4 treatment improved immune and coagulation functions and reduced internal bleeding and edema. Importantly, anti-cANGPTL4 antibody, when used concurrently with either conventional antibiotics or antipneumolysin antibody, prolonged the median survival of mice compared to monotherapy. Anti-cANGPTL4 treatment enhanced immune cell phagocytosis of bacteria while restricting excessive inflammation. This modification of immune responses improved the disease outcomes of secondary pneumococcal pneumonia. Taken together, our study emphasizes that host-directed therapeutic strategies are viable adjuncts to standard antimicrobial treatments.IMPORTANCE Despite extensive global efforts, secondary bacterial pneumonia still represents a major cause of death in developing countries and is an important cause of long-term functional disability arising from lung tissue damage. Newer approaches to improving treatment outcomes are needed to reduce the significant morbidity and mortality caused by infectious diseases. Our study, using an experimental mouse model of secondary S. pneumoniae infection, shows that a multimodal treatment that concurrently targets host and pathogen factors improved lung tissue integrity and extended the median survival time of infected mice. The immunoneutralization of host protein cANGPTL4 reduced the severity of pulmonary edema and damage. We show that host-directed therapeutic strategies as well as neutralizing antibodies against pathogen virulence factors are viable adjuncts to standard antimicrobial treatments such as antibiotics. In view of their different modes of action compared to antibiotics, concurrent immunotherapies using antibodies are potentially efficacious against secondary pneumococcal pneumonia caused by antibiotic-resistant pathogens.

Reactive oxygen species: a volatile driver of field cancerization and metastasis

Field cancerization and metastasis are the leading causes for cancer recurrence and mortality in cancer patients. The formation of primary, secondary tumors or metastasis is greatly influenced by multifaceted tumor-stroma interactions, in which stromal components of the tumor microenvironment (TME) can affect the behavior of the cancer cells. Many studies have identified cytokines and growth factors as cell signaling molecules that aid cell to cell communication. However, the functional contribution of reactive oxygen species (ROS), a family of volatile chemicals, as communication molecules are less understood. Cancer cells and various tumor-associated stromal cells produce and secrete a copious amount of ROS into the TME. Intracellular ROS modulate cell signaling cascades that aid in the acquisition of several hallmarks of cancers. Extracellular ROS help to propagate, amplify, and effectively create a mutagenic and oncogenic field which facilitate the formation of multifoci tumors and act as a springboard for metastatic tumor cells. In this review, we summarize our current knowledge of ROS as atypical paracrine signaling molecules for field cancerization and metastasis. Field cancerization and metastasis are often discussed separately; we offer a model that placed these events with ROS as the focal instigating agent in a broader "seed-soil" hypothesis.

Role of miR-486-5p in regulating renal cell carcinoma cell proliferation and apoptosis via TGF-β-activated kinase 1

Renal cell carcinoma (RCC) is a common kidney tumor in adults. The role of miR-486-5p in RCC is unknown. The aim of our study was to identify new targets regulated by miR-486-5p in RCC, to obtain a deeper insight into the network and to better understand the role of these microRNAs and their targets in carcinogenesis of RCC. We performed a series of tests and found consistently lower expression levels of miR-486-5p in kidney cancer cells. Restoration of miR-486-5p expression in RCC cells could lead to the suppression of cell proliferation and the increase of cell apoptosis. Further studies demonstrated that TGF-β-activated kinase 1 was a target gene of miR-486-5p in kidney cancer cells. It was also shown that C-C motif chemokine ligand 2 (CCL2) from tumor-associated macrophages downregulated miR-486-5p expression, and miR-486-5p inhibited RCC cell proliferation and apoptosis resistance induced by CCL2. The study demonstrates that there are potential diagnosis and therapy values of miR-486-5p in RCC.

miR-3656 expression enhances the chemosensitivity of pancreatic cancer to gemcitabine through modulation of the RHOF/EMT axis

The highly refractory nature of pancreatic cancer (PC) to chemotherapeutic drugs is one of the key reasons contributing to the poor prognosis of this disease. MicroRNAs (miRNAs) are key regulators of gene expression and have been implicated in a variety of processes from cancer development through to drug resistance. Herein, through miRNA profiling of gemcitabine-resistant (GR) and parental PANC-1 cell lines, we found a consistent reduction of miR-3656 in GR PANC-1 cells. miR-3656 overexpression enhanced the antitumor effect of gemcitabine, whereas silencing of miR-3656 resulted in the opposite effect. By performing mechanistic studies using both in vitro and in vivo models, we found that miR-3656 could target RHOF, a member of the Rho subfamily of small GTPases, and regulate the EMT process. Moreover, enforced EMT progression via TWIST1 overexpression compromised the chemotherapy-enhancing effects of miR-3656. Finally, we found significantly lower levels of miR-3656 and higher levels of RHOF in PC tissues compared with adjacent noncancerous pancreatic tissues, and this was also associated with poor PC patients’ prognosis. Taken together, our results suggest that the miR-3656/RHOF/EMT axis is an important factor involved in regulating GR in PC, and highlights the potential of novel miR-3656-based clinical modalities as a therapeutic approach in PC patients.

Targeting nuclear receptors in cancer-associated fibroblasts as concurrent therapy to inhibit development of chemoresistant tumors

Most anticancer therapies to date focus on druggable features of tumor epithelia. Despite the increasing repertoire of treatment options, patient responses remain varied. Moreover, tumor resistance and relapse remain persistent clinical challenges. These observations imply an incomplete understanding of tumor heterogeneity. The tumor microenvironment is a major determinant of disease progression and therapy outcome. Cancer-associated fibroblasts (CAFs) are the dominant cell type within the reactive stroma of tumors. They orchestrate paracrine pro-tumorigenic signaling with adjacent tumor cells, thus exacerbating the hallmarks of cancer and accelerating tumor malignancy. Although CAF-derived soluble factors have been investigated for tumor stroma-directed therapy, the underlying transcriptional programs that enable the oncogenic functions of CAFs remain poorly understood. Nuclear receptors (NRs), a large family of ligand-responsive transcription factors, are pharmacologically viable targets for the suppression of CAF-facilitated oncogenesis. In this study, we defined the expression profiles of NRs in CAFs from clinical cutaneous squamous cell carcinoma (SCC) biopsies. We further identified a cluster of driver NRs in CAFs as important modifiers of CAF function with profound influence on cancer cell invasiveness, proliferation, drug resistance, energy metabolism and oxidative stress status. Importantly, guided by the NR profile of CAFs, retinoic acid receptor β and androgen receptor antagonists were identified for concurrent therapy with cisplatin, resulting in the inhibition of chemoresistance in recurred SCC:CAF xenografts. Our work demonstrates that treatments targeting both the tumor epithelia and the surrounding CAFs can extend the efficacy of conventional chemotherapy.

Expression and function of transforming growth factor‑β‑activated protein kinase 1 in gastric cancer

The present study aimed to investigate the expression and role of transforming growth factor (TGF) ‑β‑activated protein kinase 1 (TAK1) in human gastric cancer. Immunohistochemistry was performed to investigate the expression of TAK1 in surgical specimens of human gastric cancer tissue and adjacent normal tissue. The association between TAK1 and clinicopathologic factors was analyzed and the association between TAK1 expression and the overall survival rates was evaluated using Kaplan‑Meier curves. In addition, the effect of the TAK1 selective inhibitor 5Z‑7‑oxozeaenol (OZ) on the biological characteristics of MGC803 human gastric cancer cells in vitro were investigated. The role of TAK1 in gastric cancer cell proliferation, apoptosis and invasion were determined by cell proliferation assays, flow cytometry analysis and transwell invasion assays, respectively. The findings of the present study demonstrated that the positive expression rate of TAK1 in gastric cancer and adjacent normal tissues was 70.5 and 25.9%, respectively. Furthermore, TAK1 expression was significantly associated with advanced N stage and pathological stage (P<0.05). Survival analysis of 139 patients with gastric cancer indicated a lower overall survival rate of patients in the TAK1‑positive group compared with the TAK1‑negative group (P<0.05). In addition, treatment with the TAK1 selective inhibitor OZ reduced the proliferation and invasion abilities of MGC803 cells and significantly reduced the expression levels of phosphorylated‑TAK1 (Thr187), nuclear p65, cyclin D1, Bcl‑2 apoptosis regulator and matrix metallopeptidase (MMP)9 (P<0.05). OZ treatment significantly increased the expression levels of cytosolic cytochrome c and cleaved caspase 3 and the apoptosis rate in MGC803 cells (P<0.05). In conclusion, these findings suggest that increased TAK1 expression may be involved in the progression of gastric cancer; therefore, TAK1 may be used as a future therapeutic target for gastric cancer treatment.

Programmable Nano-Bio Interfaces for Functional Biointegrated Devices

A large amount of evidence has demonstrated the revolutionary role of nanosystems in the screening and shielding of biological systems. The explosive development of interfacing bioentities with programmable nanomaterials has conveyed the intriguing concept of nano-bio interfaces. Here, recent advances in functional biointegrated devices through the precise programming of nano-bio interactions are outlined, especially with regard to the rational assembly of constituent nanomaterials on multiple dimension scales (e.g., nanoparticles, nanowires, layered nanomaterials, and 3D-architectured nanomaterials), in order to leverage their respective intrinsic merits for different functions. Emerging nanotechnological strategies at nano-bio interfaces are also highlighted, such as multimodal diagnosis or "theragnostics", synergistic and sequential therapeutics delivery, and stretchable and flexible nanoelectronic devices, and their implementation into a broad range of biointegrated devices (e.g., implantable, minimally invasive, and wearable devices). When utilized as functional modules of biointegrated devices, these programmable nano-bio interfaces will open up a new chapter for precision nanomedicine.

ANGPTL4 T266M variant is associated with reduced cancer invasiveness

Angiopoietin-like 4 (ANGPTL4) is a secretory protein that can be cleaved to form an N-terminal and a C-terminal protein. Studies performed thus far have linked ANGPTL4 to several cancer-related and metabolic processes. Notably, several point mutations in the C-terminal ANGPTL4 (cANGPTL4) have been reported, although no studies have been performed that ascribed these mutations to cancer-related and metabolic processes. In this study, we compared the characteristics of tumors with and without wild-type (wt) cANGPTL4 and tumors with cANGPTL4 bearing the T266M mutation (T266M cANGPTL4). We found that T266M cANGPTL4 bound to integrin α5β1 with a reduced affinity compared to wt, leading to weaker activation of downstream signaling molecules. The mutant tumors exhibited impaired proliferation, anoikis resistance, and migratory capability and had reduced adenylate energy charge. Further investigations also revealed that cANGPTL4 regulated the expression of Glut2. These findings may explain the differences in the tumor characteristics and energy metabolism observed with the cANGPTL4 T266M mutation compared to tumors without the mutation.

Diverse Applications of Nanomedicine

The design and use of materials in the nanoscale size range for addressing medical and health-related issues continues to receive increasing interest. Research in nanomedicine spans a multitude of areas, including drug delivery, vaccine development, antibacterial, diagnosis and imaging tools, wearable devices, implants, high-throughput screening platforms, etc. using biological, nonbiological, biomimetic, or hybrid materials. Many of these developments are starting to be translated into viable clinical products. Here, we provide an overview of recent developments in nanomedicine and highlight the current challenges and upcoming opportunities for the field and translation to the clinic.

Genome-wide gain-of-function screen for genes that induce epithelial-to-mesenchymal transition in breast cancer

Epithelial to mesenchymal transition (EMT) is a developmental program that has been implicated in progression, metastasis and therapeutic resistance of some carcinomas. To identify genes whose overexpression drives EMT, we screened a lentiviral expression library of 17000 human open reading frames (ORFs) using high-content imaging to quantitate cytoplasmic vimentin. Hits capable of increasing vimentin in the mammary carcinoma-derived cell line MDA-MB-468 were confirmed in the non-tumorigenic breast-epithelial cell line MCF10A. When overexpressed in this model, they increased the rate of cell invasion through Matrigel™, induced mesenchymal marker expression and reduced expression of the epithelial marker E-cadherin. In gene-expression datasets derived from breast cancer patients, the expression of several novel genes correlated with expression of known EMT marker genes, indicating their in vivo relevance. As EMT-associated properties are thought to contribute in several ways to cancer progression, genes identified in this study may represent novel targets for anti-cancer therapy.

Low molecular weight protein tyrosine phosphatase: Multifaceted functions of an evolutionarily conserved enzyme

Originally identified as a low molecular weight acid phosphatase, LMW-PTP is actually a protein tyrosine phosphatase that acts on many phosphotyrosine-containing cellular proteins that are primarily involved in signal transduction. Differences in sequence, structure, and substrate recognition as well as in subcellular localization in different organisms enable LMW-PTP to exert many different functions. In fact, during evolution, the LMW-PTP structure adapted to perform different catalytic actions depending on the organism type. In bacteria, this enzyme is involved in the biosynthesis of group 1 and 4 capsules, but it is also a virulence factor in pathogenic strains. In yeast, LMW-PTPs dephosphorylate immunophilin Fpr3, a peptidyl-prolyl-cis-trans isomerase member of the protein chaperone family. In humans, LMW-PTP is encoded by the ACP1 gene, which is composed of three different alleles, each encoding two active enzymes produced by alternative RNA splicing. In animals, LMW-PTP dephosphorylates a number of growth factor receptors and modulates their signalling processes. The involvement of LMW-PTP in cancer progression and in insulin receptor regulation as well as its actions as a virulence factor in a number of pathogenic bacterial strains may promote the search for potent, selective and bioavailable LMW-PTP inhibitors.

Mechanisms of TGFβ-Induced Epithelial-Mesenchymal Transition

Transitory phenotypic changes such as the epithelial–mesenchymal transition (EMT) help embryonic cells to generate migratory descendants that populate new sites and establish the distinct tissues in the developing embryo. The mesenchymal descendants of diverse epithelia also participate in the wound healing response of adult tissues, and facilitate the progression of cancer. EMT can be induced by several extracellular cues in the microenvironment of a given epithelial tissue. One such cue, transforming growth factor β (TGFβ), prominently induces EMT via a group of specific transcription factors. The potency of TGFβ is partly based on its ability to perform two parallel molecular functions, i.e. to induce the expression of growth factors, cytokines and chemokines, which sequentially and in a complementary manner help to establish and maintain the EMT, and to mediate signaling crosstalk with other developmental signaling pathways, thus promoting changes in cell differentiation. The molecules that are activated by TGFβ signaling or act as cooperating partners of this pathway are impossible to exhaust within a single coherent and contemporary report. Here, we present selected examples to illustrate the key principles of the circuits that control EMT under the influence of TGFβ.

Contractile dynamics change before morphological cues during fluorescence [corrected] illumination

Illumination can have adverse effects on live cells. However, many experiments, e.g. traction force microscopy, rely on fluorescence microscopy. Current methods to assess undesired photo-induced cell changes rely on qualitative observation of changes in cell morphology. Here we utilize a quantitative technique to identify the effect of light on cell contractility prior to morphological changes. Fibroblasts were cultured on soft elastic hydrogels embedded with fluorescent beads. The adherent cells generated contractile forces that deform the substrate. Beads were used as fiducial markers to quantify the substrate deformation over time, which serves as a measure of cell force dynamics. We find that cells exposed to moderate fluorescence illumination (λ = 540–585 nm, I = 12.5 W/m², duration = 60 s) exhibit rapid force relaxation. Strikingly, cells exhibit force relaxation after only 2 s of exposure, suggesting that photo-induced relaxation occurs nearly immediately. Evidence of photo-induced morphological changes were not observed for 15–30 min after illumination. Force relaxation and morphological changes were found to depend on wavelength and intensity of excitation light. This study demonstrates that changes in cell contractility reveal evidence of a photo-induced cell response long before any morphological cues.

Targeting of TGF-β-activated protein kinase 1 inhibits chemokine (C-C motif) receptor 7 expression, tumor growth and metastasis in breast cancer

TGF-β-activated protein kinase 1 (TAK1) is a critical mediator in inflammation, immune response and cancer development. Our previous study demonstrated that activation of TAK1 increases the expression of chemokine (C-C motif) receptor 7 (CCR7) and promotes lymphatic invasion ability of breast cancer cells. However, the expression and association of activated TAK1 and CCR7 in breast tumor tissues is unknown and the therapeutic effect by targeting TAK1 is also unclear. We showed that activated TAK1 (as indicated by phospho-TAK1) and its binding protein TAB1 are strongly expressed in breast tumor tissues (77% and 74% respectively). In addition, increase of phospho-TAK1 or TAB1 is strongly associated with over-expression of CCR7. TAK1 inhibitor 5Z-7-Oxozeaenol (5Z-O) inhibited TAK1 activity, suppressed downstream signaling pathways including p38, IκB kinase (IKK) and c-Jun N-terminal kinase (JNK) and reduced CCR7 expression in metastatic MDA-MB-231 cells. In addition, 5Z-O repressed NF-κB- and c-JUN-mediated transcription of CCR7 gene. Knockdown of TAB1 attenuated CCR7 expression and tumor growth in an orthotopic animal study. More importantly, lymphatic invasion and lung metastasis were suppressed. Collectively, our results demonstrate that constitutive activation of TAK1 is frequently found in human breast cancer and this kinase is a potential therapeutic target for this cancer.

Coordinate loss of MAP3K7 and CHD1 promotes aggressive prostate cancer

Prostate cancer subtypes are poorly defined and functional validation of drivers of ETS rearrangement-negative prostate cancer has not been conducted. Here, we identified an ETS(-) subtype of aggressive prostate cancer (ERG(-)MAP3K7(del)CHD1(del)) and used a novel developmental model and a cell line xenograft model to show that cosuppression of MAP3K7 and CHD1 expression promotes aggressive disease. Analyses of publicly available prostate cancer datasets revealed that MAP3K7 and CHD1 were significantly codeleted in 10% to 20% of localized tumors and combined loss correlated with poor disease-free survival. To evaluate the functional impact of dual MAP3K7-CHD1 loss, we suppressed Map3k7 and/or Chd1 expression in mouse prostate epithelial progenitor/stem cells (PrP/SC) and performed tissue recombination experiments in vivo. Dual shMap3k7-shChd1 PrP/SC recombinants displayed massive glandular atypia with regions of prostatic intraepithelial neoplasia and carcinoma apparent. Combined Map3k7-Chd1 suppression greatly disrupted normal prostatic lineage differentiation; dual recombinants displayed significant androgen receptor loss, increased neuroendocrine differentiation, and increased neural differentiation. Clinical samples with dual MAP3K7-CHD1 loss also displayed neuroendocrine and neural characteristics. In addition, dual Map3k7-Chd1 suppression promoted E-cadherin loss and mucin production in recombinants. MAP3K7 and CHD1 protein loss also correlated with Gleason grade and E-cadherin loss in clinical samples. To further validate the phenotype observed in the PrP/SC model, we suppressed MAP3K7 and/or CHD1 expression in LNCaP prostate cancer cells. Dual shMAP3K7-shCHD1 LNCaP xenografts displayed increased tumor growth and decreased survival compared with shControl, shMAP3K7, and shCHD1 xenografts. Collectively, these data identify coordinate loss of MAP3K7 and CHD1 as a unique driver of aggressive prostate cancer development.

TGF-β1 induced transdifferentiation of rpe cells is mediated by TAK1

BACKGROUND AND AIM

Proliferative vitreoretinopathy (PVR) is an active process that develops as a complication upon retinal detachment (RD), accompanied by formation of fibrotic tissue. The main cells involved in the development of fibrotic tissue during PVR are the retinal pigment epithelial (RPE) cells. The RPE cells undergo epithelial-mesenchymal transition (EMT) which leads to complex retinal detachment and loss of vision. Transforming growth factor-β1 (TGF-β1) is considered as the main player in the EMT of RPE cells, even though the mechanism is not fully understood. This study was performed to determine the possible involvement of transforming growth factor β activated kinase 1 (TAK1) in the EMT process of the RPE cells.

METHODOLOGY

ARPE-19 Cells were treated with 5Z-7 oxozeaenol (TAK1 inhibitor) or SB431542 (TGF-β1 receptor kinase inhibitor) followed by TGF-β1 stimulation. Immunofluorescence, scratch assay Real time PCR and collagen contraction assay assessed the EMT features. The phosphorylation of Smad2/3 and p38 was examined using western blots analysis.

RESULTS

This study demonstrates that stimulation of RPE cells with TGF-β1 increases α-SMA expression, cell migration and cell contractility, all of which are EMT features. Remarkably, addition of TAK1 inhibitor abolishes all these processes. Furthermore, we show hereby that TAK1 regulates not only the activation of the non-canonical cascade of TGF-β1 (p38), but also the canonical cascade, the Smad2/3 activation. Thus, the outcome of the TGF-β response in RPE cells is TAK1 dependent.

CONCLUSIONS/SIGNIFICANCE

This work demonstrated TAK1, a component of the non-canonical pathway of TGF-β1, is a key player in the EMT process, thus provides deep insight into the pathogenesis of PVR. The ability to halt the process of EMT in RPE cells may reduce the severity of the fibrotic response that occurs upon PVR, leading to a better prognosis and increase the probability of success in RD treatment.

Endothelial Cell Senescence Increases Traction Forces due to Age-Associated Changes in the Glycocalyx and SIRT1

Endothelial cell (EC) aging and senescence are key events in atherogenesis and cardiovascular disease development. Age-associated changes in the local mechanical environment of blood vessels have also been linked to atherosclerosis. However, the extent to which cell senescence affects mechanical forces generated by the cell is unclear. In this study, we sought to determine whether EC senescence increases traction forces through age-associated changes in the glycocalyx and antioxidant regulator deacetylase Sirtuin1 (SIRT1), which is downregulated during aging. Traction forces were higher in cells that had undergone more population doublings and changes in traction force were associated with altered actin localization. Older cells also had increased actin filament thickness. Depletion of heparan sulfate in young ECs elevated traction forces and actin filament thickness, while addition of heparan sulfate to the surface of aged ECs by treatment with angiopoietin-1 had the opposite effect. While inhibition of SIRT1 had no significant effect on traction forces or actin organization for young cells, activation of SIRT1 did reduce traction forces and increase peripheral actin in aged ECs. These results show that EC senescence increases traction forces and alters actin localization through changes to SIRT1 and the glycocalyx.

Orthogonally engineering matrix topography and rigidity to regulate multicellular morphology

Programmable polymer substrates, which mimic the variable extracellular matrices in living systems, are used to regulate multicellular morphology, via orthogonally modulating the matrix topography and elasticity. The multicellular morphology is dependent on the competition between cell-matrix adhesion and cell-cell adhesion. Decreasing the cell-matrix adhesion provokes cytoskeleton reorganization, inhibits lamellipodial crawling, and thus enhances the leakiness of multicellular morphology.