Mechanisms of the epithelial-mesenchymal transition by TGF-beta

Overview of Evidence-Based Chemotherapy for Oral Cancer: Focus on Drug Resistance Related to the Epithelial-Mesenchymal Transition

The increasing incidence of resistance to chemotherapeutic agents has become a major issue in the treatment of oral cancer (OC). Epithelial-mesenchymal transition (EMT) has attracted a great deal of attention in recent years with regard to its relation to the mechanism of chemotherapy drug resistance. EMT-activating transcription factors (EMT-ATFs), such as Snail, TWIST, and ZEB, can activate several different molecular pathways, e.g., PI3K/AKT, NF-κB, and TGF-β. In contrast, the activated oncological signal pathways provide reciprocal feedback that affects the expression of EMT-ATFs, resulting in a peritumoral extracellular environment conducive to cancer cell survival and evasion of the immune system, leading to resistance to multiple chemotherapeutic agents. We present an overview of evidence-based chemotherapy for OC treatment based on the National Comprehensive Cancer Network (NCCN) Chemotherapy Order Templates. We focus on the molecular pathways involved in drug resistance related to the EMT and highlight the signal pathways and transcription factors that may be important for EMT-regulated drug resistance. Rapid progress in antitumor regimens, together with the application of powerful techniques such as high-throughput screening and microRNA technology, will facilitate the development of therapeutic strategies to augment chemotherapy.

Inferring transcriptomic cell states and transitions only from time series transcriptome data

Cellular stages of biological processes have been characterized using fluorescence-activated cell sorting and genetic perturbations, charting a limited landscape of cellular states. Time series transcriptome data can help define new cellular states at the molecular level since the analysis of transcriptional changes can provide information on cell states and transitions. However, existing methods for inferring cell states from transcriptome data use additional information such as prior knowledge on cell types or cell-type-specific markers to reduce the complexity of data. In this study, we present a novel time series clustering framework to infer TRAnscriptomic Cellular States (TRACS) only from time series transcriptome data by integrating Gaussian process regression, shape-based distance, and ranked pairs algorithm in a single computational framework. TRACS determines patterns that correspond to hidden cellular states by clustering gene expression data. TRACS was used to analyse single-cell and bulk RNA sequencing data and successfully generated cluster networks that reflected the characteristics of key stages of biological processes. Thus, TRACS has a potential to help reveal unknown cellular states and transitions at the molecular level using only time series transcriptome data. TRACS is implemented in Python and available at http://github.com/BML-cbnu/TRACS/ .

Effects of Different Concentrations of Transforming Growth Factor β_1 (TGF-β_1) on the Number and Transdifferentiation of Endometrial Epithelial Cells in Endometrial Tissue

To study the influence of different concentrations of TGF-β_1 on the number and transdifferentiation of epithelial cells in endometrial tissue. 40 cases of normal endometrial tissue obtained by surgery in our hospital were collected, and epithelial cells were separated. According to the random number table method, cells were assigned into normal control groups (only with culture solution) and experimental groups (TGF-β1 was added on the basis of the above), the experimental group is further assigned into three groups, that is, low-dose (3 ng/ml), medium-dose (6 ng/ml) and high-dose (9 ng/ml) TGF-β_1 group followed by analysis of cell numbers, FN, α-SMA and Col-I level. FN secretion in normal control group was (0.469±0.010) ng/L, and ColI secretion was (0.532±0.033) ng/L. There was a difference between FN values and Col-I values in each experimental group (P < 0.01); α-SMA and other data in the experimental group had opposite effects compared with control group with significant differences for different concentrations of TGF-β_1. As concentration gradually increased, E-cadherin level in cytoplasm will gradually decrease. On the contrary, α-SMA level in cytoplasm will gradually increase (P < 0.05) (F = 145.125, 179.511, P < 0.01). TGF-β_1 stimulates the increase in of number of epithelial cells in endometrial tissue and induces them to transform into myofibroblasts dose dependently

Nannocystin Ax, a natural elongation factor 1α inhibitor from Nannocystis sp., suppresses epithelial-mesenchymal transition, adhesion and migration in lung cancer cells

Epithelial-mesenchymal transition (EMT), the epithelial cells transdifferentiation into the mesenchymal cells, has been involved in cancer metastasis. Nannocystin ax (NAN) is a cyclodepsipeptide initially isolated from Myxobacterial genus, Nannocystis sp. with anticancer activities. This study was designed to explore the effect of NAN on TGF-β1-induced EMT in lung cancer cells. The morphological alteration was observed with a microscope. Western blotting and immunofluorescence assays were used to detect the protein expression and the localization. The adhesion and migration were evaluated by adhesion assay and wound healing assay. The mRNA expression of TGF-β receptor type I (TβRI) was determined by real-time PCR. NAN significantly restrained TGF-β1-induced EMT morphological changes, the protein expression of E-cadherin, N-cadherin, and Vimentin, etc. TGF-β1 activated phosphorylation and nuclear translocation of Smad2/3 were inhibited by NAN. Furthermore, NAN suppressed adhesion and migration triggered by TGF-β1. In addition, NAN significantly down-regulated TβRI on the transcriptional level directly. In summary, these results showed that NAN restrained TGF-β1-induced epithelial-mesenchymal transition, migration, and adhesion in human lung cancer cells. The underlying mechanism involved the inhibition of Smad2/3 and the TβRI signaling pathway. This study reveals the new anticancer effect and mechanism of NAN.

Plasmin and Plasminogen System in the Tumor Microenvironment: Implications for Cancer Diagnosis, Prognosis, and Therapy

Simple Summary

In this review, we present a detailed discussion of how the plasminogen-activation system is utilized by tumor cells in their unrelenting attack on the tissues surrounding them. Plasmin is an enzyme which is responsible for digesting several proteins that hold the tissues surrounding solid tumors together. In this process tumor cells utilize the activity of plasmin to digest tissue barriers in order to leave the tumour site and spread to other parts of the body. We specifically focus on the role of plasminogen receptor—p11 which is an important regulatory protein that facilitates the conversion of plasminogen to plasmin and by this means promotes the attack by the tumour cells on their surrounding tissues.

Abstract

The tumor microenvironment (TME) is now being widely accepted as the key contributor to a range of processes involved in cancer progression from tumor growth to metastasis and chemoresistance. The extracellular matrix (ECM) and the proteases that mediate the remodeling of the ECM form an integral part of the TME. Plasmin is a broad-spectrum, highly potent, serine protease whose activation from its precursor plasminogen is tightly regulated by the activators (uPA, uPAR, and tPA), the inhibitors (PAI-1, PAI-2), and plasminogen receptors. Collectively, this system is called the plasminogen activation system. The expression of the components of the plasminogen activation system by malignant cells and the surrounding stromal cells modulates the TME resulting in sustained cancer progression signals. In this review, we provide a detailed discussion of the roles of plasminogen activation system in tumor growth, invasion, metastasis, and chemoresistance with specific emphasis on their role in the TME. We particularly review the recent highlights of the plasminogen receptor S100A10 (p11), which is a pivotal component of the plasminogen activation system.

Is Carboxypeptidase B1 a Prognostic Marker for Ductal Carcinoma In Situ?

Simple Summary

Ductal carcinoma in situ (DCIS) is an early-stage breast cancer (BC), in which tumor cells are growing in a localized duct of the mammary gland. DCIS is considered a precursor disease for invasive BC and, therefore, treated as soon as it is identified. However, low-grade DCIS can be confused with atypical ductal hyperplasia, which is not a malignant lesion, leading to unnecessary surgery in around 70% of women with suspected DCIS. On the other hand, if left untreated, a DCIS has the potential to progress to IDC. In this retrospective study, we identified a gene signature, carboxypeptidase B1 (CPB1), the expression of which could help differentiate DCIS from an ADH lesion and DCIS that may progress to an invasive BC.

Abstract

Ductal carcinoma in situ (DCIS) is considered a non-obligatory precursor for invasive ductal carcinoma (IDC). Around 70% of women with atypical ductal hyperplasia (ADH) undergo unnecessary surgery due to the difficulty in differentiating ADH from low-grade DCIS. If untreated, 14–60% of DCIS progress to IDC, highlighting the importance of identifying a DCIS gene signature. Human transcriptome data of breast tissue samples representing each step of BC progression were analyzed and high expression of carboxypeptidase B1 (CPB1) expression strongly correlated with DCIS. This was confirmed by quantitative PCR in breast tissue samples and cell lines model. High CPB1 expression correlated with better survival outcome, and mRNA level was highest in DCIS than DCIS adjacent to IDC and IDC. Moreover, loss of CPB1 in a DCIS cell line led to invasive properties associated with activation of HIF1α, FN1, STAT3 and SPP1 and downregulation of SFRP1 and OS9. The expression of CPB1 could predict 90.1% of DCIS in a cohort consisting of DCIS and IDC. We identified CPB1, a biomarker that helps differentiate DCIS from ADH or IDC and in predicting if a DCIS is likely to progress to IDC, thereby helping clinicians in their decisions.

Transforming Growth Factor-β1 Enhances Mesenchymal Characteristics of Buffalo (Bubalus bubalis) Bone Marrow-Derived Mesenchymal Stem Cells

Bone marrow-derived mesenchymal stem cells (BMSCs) from livestock are valuable resources for animal reproduction and veterinary therapeutics. Previous studies have shown that BMSCs were prone to malignant transformation of mesenchymal-to-epithelial transition in vitro, which can cause many barriers to further application of BMSCs. The transforming growth factor β (TGF-β) signaling pathway has been widely studied as the most important signaling pathway involved in regulating mesenchymal features of BMSCs. However, the effects of the TGF-β signaling pathway on mesenchymal characteristics of buffalo BMSCs (bBMSCs) remain unclear. In the present study, the impacts of the growth factor, TGF-β1, on cell proliferation, apoptosis, migration, and karyotype of bBMSCs were tested. Besides, the effects of TGF-β1 on pluripotency, mesenchymal markers, and epithelial-to-mesenchymal transition (EMT)-related gene expression of bBMSCs were also examined. Results showed that the suitable concentration and time of TGF-β1 treatment (2 ng/mL and 24 hours) promoted cell proliferation and significantly reduced cell apoptosis (p < 0.05) in bBMSCs. The cell migration capacity and normal karyotype rate of bBMSCs were significantly (p < 0.05) improved under TGF-β1 treatment. The expression levels of pluripotency-related genes (Sox2 and Nanog) and mesenchymal markers (N-cadherin and Fn1) were significantly (p < 0.05) up-regulated under TGF-β1 treatment. Furthermore, TGF-β1 activated the EMT process, thereby contributing to significantly enhancing the expression levels of EMT-related genes (Snail and Slug) (p < 0.05), which in turn improved maintenance of the mesenchymal nature in bBMSCs. Finally, bBMSCs underwent self-transformation more easily and efficiently and exhibited more characteristics of mesenchymal stem cells under TGF-β1 treatment. This study provides theoretical guidance for elucidating the detailed mechanism of the TGF-β signaling pathway in mesenchymal feature maintenance of bBMSCs and is of significance to establish a stable culture system of bBMSCs.

Transcriptome Landscape of Epithelial to Mesenchymal Transition of Human Stem Cell-Derived RPE

Purpose

RPE injury often induces epithelial to mesenchymal transition (EMT). Although RPE-EMT has been implicated in a variety of retinal diseases, including proliferative vitroretinopathy, neovascular and atrophic AMD, and diabetic retinopathy, it is not well-understood at the molecular level. To contribute to our understanding of EMT in human RPE, we performed a time-course transcriptomic analysis of human stem cell-derived RPE (hRPE) monolayers induced to undergo EMT using 2 independent, yet complementary, model systems.

Methods

EMT of human stem cell-derived RPE monolayers was induced by either enzymatic dissociation or modulation of TGF-β signaling. Transcriptomic analysis of cells at different stages of EMT was performed by RNA-sequencing, and select findings were confirmed by reverse transcription quantitative PCR and immunostaining. An ingenuity pathway analysis (IPA) was performed to identify signaling pathways and regulatory networks associated with EMT.

Results

Proteocollagenolytic enzymatic dissociation and cotreatment with TGF-β and TNF-α both induce EMT in human stem cell-derived RPE monolayers, leading to an increased expression of mesenchymal factors and a decreased expression of RPE differentiation-associated factors. Ingenuity pathway analysis identified the upstream regulators of the RPE-EMT regulatory networks and identified master switches and nodes during RPE-EMT. Of particular interest was the identification of widespread dysregulation of axon guidance molecules during RPE-EMT progression.

Conclusions

The temporal transcriptome profiles described here provide a comprehensive resource of the dynamic signaling events and the associated biological pathways that underlie RPE-EMT onset. The pathways defined by these studies may help to identify targets for the development of novel therapeutic targets for the treatment of retinal disease.

Identification of extracellular matrix proteins secreted by human dermal fibroblasts cultured in 3D electrospun scaffolds

The appreciation that cell interactions in tissues is dependent on their three dimensional (3D) distribution has stimulated the development of 3D cell culture models. We constructed an artificial 3D tumour by culturing human breast cancer JIMT-1 cells and human dermal fibroblasts (HDFs) in a 3D network of electrospun polycaprolactone fibres. Here, we investigate ECM components produced by the cells in the artificial 3D tumour, which is an important step in validating the model. Immunostaining and confocal fluorescence microscopy show that the ECM proteins fibronectin, collagen I, and laminin are deposited throughout the entire 3D structure. Secreted soluble factors including matrix metalloproteinases (MMPs) and interleukine-6 (IL-6) were analysed in collected medium and were found to be mainly derived from the HDFs. Treatment with transforming growth factor-β1 (TGF-β1), a major cytokine found in a tumour, significantly alters the MMP activity and IL-6 concentration. In addition, TGF-β1 treatment, changes the morphology of the HDFs to become more elongated and with increased linearized actin filaments compared to non-treated HDFs. Collectively, these novel findings suggest that the artificial 3D tumour displays a clear cell distribution and ECM deposition that resembles a tumour environment in vivo, suggesting an innovative biological model to study a human tumour.

Acetylation of KLF5 maintains EMT and tumorigenicity to cause chemoresistant bone metastasis in prostate cancer

Advanced prostate cancer (PCa) often develops bone metastasis, for which therapies are very limited and the underlying mechanisms are poorly understood. We report that bone-borne TGF-β induces the acetylation of transcription factor KLF5 in PCa bone metastases, and acetylated KLF5 (Ac-KLF5) causes osteoclastogenesis and bone metastatic lesions by activating CXCR4, which leads to IL-11 secretion, and stimulating SHH/IL-6 paracrine signaling. While essential for maintaining the mesenchymal phenotype and tumorigenicity, Ac-KLF5 also causes resistance to docetaxel in tumors and bone metastases, which is overcome by targeting CXCR4 with FDA-approved plerixafor. Establishing a mechanism for bone metastasis and chemoresistance in PCa, these findings provide a rationale for treating chemoresistant bone metastasis of PCa with inhibitors of Ac-KLF5/CXCR4 signaling.

Organ Fibrosis and Autoimmunity: The Role of Inflammation in TGFβ-Dependent EMT

Recent advances in our understanding of the molecular pathways that control the link of inflammation with organ fibrosis and autoimmune diseases point to the epithelial to mesenchymal transition (EMT) as the common association in the progression of these diseases characterized by an intense inflammatory response. EMT, a process in which epithelial cells are gradually transformed to mesenchymal cells, is a major contributor to the pathogenesis of fibrosis. Importantly, the chronic inflammatory microenvironment has emerged as a decisive factor in the induction of pathological EMT. Transforming growth factor-β (TGF-β), a multifunctional cytokine, plays a crucial role in the induction of fibrosis, often associated with chronic phases of inflammatory diseases, contributing to marked fibrotic changes that severely impair normal tissue architecture and function. The understanding of molecular mechanisms underlying EMT-dependent fibrosis has both a basic and a translational relevance, since it may be useful to design therapies aimed at counteracting organ deterioration and failure. To this end, we reviewed the recent literature to better elucidate the molecular response to inflammatory/fibrogenic signals in autoimmune diseases in order to further the specific regulation of EMT-dependent fibrosis in more targeted therapies.

Cancer stem cells and macrophages: molecular connections and future perspectives against cancer

Cancer stem cells (CSCs) have been considered the key drivers of cancer initiation and progression due to their unlimited self-renewal capacity and their ability to induce tumor formation. Macrophages, particularly tumor-associated macrophages (TAMs), establish a tumor microenvironment to protect and induce CSCs development and dissemination. Many studies in the past decade have been performed to understand the molecular mediators of CSCs and TAMs, and several studies have elucidated the complex crosstalk that occurs between these two cell types. The aim of this review is to define the complex crosstalk between these two cell types and to highlight potential future anti-cancer strategies.

Regulation of breast cancer metastasis signaling by miRNAs

Despite the decline in death rate from breast cancer and recent advances in targeted therapies and combinations for the treatment of metastatic disease, metastatic breast cancer remains the second leading cause of cancer-associated death in U.S. women. The invasion-metastasis cascade involves a number of steps and multitudes of proteins and signaling molecules. The pathways include invasion, intravasation, circulation, extravasation, infiltration into a distant site to form a metastatic niche, and micrometastasis formation in a new environment. Each of these processes is regulated by changes in gene expression. Noncoding RNAs including microRNAs (miRNAs) are involved in breast cancer tumorigenesis, progression, and metastasis by post-transcriptional regulation of target gene expression. miRNAs can stimulate oncogenesis (oncomiRs), inhibit tumor growth (tumor suppressors or miRsupps), and regulate gene targets in metastasis (metastamiRs). The goal of this review is to summarize some of the key miRNAs that regulate genes and pathways involved in metastatic breast cancer with an emphasis on estrogen receptor α (ERα+) breast cancer. We reviewed the identity, regulation, human breast tumor expression, and reported prognostic significance of miRNAs that have been documented to directly target key genes in pathways, including epithelial-to-mesenchymal transition (EMT) contributing to the metastatic cascade. We critically evaluated the evidence for metastamiRs and their targets and miRNA regulation of metastasis suppressor genes in breast cancer progression and metastasis. It is clear that our understanding of miRNA regulation of targets in metastasis is incomplete.

Epigenetic Alterations in Renal Cell Cancer With TKIs Resistance: From Mechanisms to Clinical Applications

The appearance of tyrosine kinase inhibitors (TKIs) has been a major breakthrough in renal cell carcinoma (RCC) therapy. Unfortunately, a portion of patients with TKIs resistance experience disease progression after TKIs therapy. Epigenetic alterations play an important role in the development of TKIs resistance. Current evidence suggests that epigenetic alterations occur frequently in RCC patients with poor response to TKIs therapy, and modulation of them could enhance the cytotoxic effect of antitumor therapy. In this review, we summarize the currently known epigenetic alterations relating to TKIs resistance in RCC, focusing on DNA methylation, non-coding RNAs (ncRNAs), histone modifications, and their interactions with TKIs treatment. In addition, we discuss application of epigenetic alteration analyses in the clinical setting to predict prognosis of patients with TKIs treatment, and the potential use of epigenetics-based therapies to surmount TKIs resistance.

Inference of Intercellular Communications and Multilayer Gene-Regulations of Epithelial-Mesenchymal Transition From Single-Cell Transcriptomic Data

Epithelial-to-mesenchymal transition (EMT) plays an important role in many biological processes during development and cancer. The advent of single-cell transcriptome sequencing techniques allows the dissection of dynamical details underlying EMT with unprecedented resolution. Despite several single-cell data analysis on EMT, how cell communicates and regulates dynamics along the EMT trajectory remains elusive. Using single-cell transcriptomic datasets, here we infer the cell-cell communications and the multilayer gene-gene regulation networks to analyze and visualize the complex cellular crosstalk and the underlying gene regulatory dynamics along EMT. Combining with trajectory analysis, our approach reveals the existence of multiple intermediate cell states (ICSs) with hybrid epithelial and mesenchymal features. Analyses on the time-series datasets from cancer cell lines with different inducing factors show that the induced EMTs are context-specific: the EMT induced by transforming growth factor B1 (TGFB1) is synchronous, whereas the EMTs induced by epidermal growth factor and tumor necrosis factor are asynchronous, and the responses of TGF-β pathway in terms of gene expression regulations are heterogeneous under different treatments or among various cell states. Meanwhile, network topology analysis suggests that the ICSs during EMT serve as the signaling in cellular communication under different conditions. Interestingly, our analysis of a mouse skin squamous cell carcinoma dataset also suggests regardless of the significant discrepancy in concrete genes between in vitro and in vivo EMT systems, the ICSs play dominant role in the TGF-β signaling crosstalk. Overall, our approach reveals the multiscale mechanisms coupling cell-cell communications and gene-gene regulations responsible for complex cell-state transitions.

Involvement of CD73 and A2B Receptor in Radiation-Induced DNA Damage Response and Cell Migration in Human Glioblastoma A172 Cells

Glioblastoma is the most common malignant tumor of the central nervous system and is treated with a combination of surgery, radiation and chemotherapy. However, the tumor often acquires radiation resistance, which is characterized by an increased DNA damage response (DDR). Here, we show that CD73, which generates extracellular adenosine from ATP, and A2B receptor, which is activated by adenosine, are involved in the γ-radiation-induced DDR and the enhanced migration ability of human glioblastoma cell line A172. To investigate DDR, we evaluated ataxia telangiectasia mutated (ATM) activation and focus formation of histone H2A isoform γ (γH2AX) and p53-binding protein 1 (53BP1) in the nucleus of A172 cells after γ-irradiation. Antagonists of A2B receptor and CD73, or knockdown with small interfering RNA (siRNA), suppressed γ-radiation-induced DDR and promoted γ-radiation-induced cell death, as well as suppressing γ-radiation-induced cell migration and actin remodeling. These results suggest that activation of A2B receptor by extracellular adenosine generated via CD73 promotes γ-radiation-induced DDR, leading to recovery from DNA damage, and also enhances cell migration and actin remodeling. The CD73-A2B receptor pathway may be a promising target for overcoming radiation resistance and the acquisition of malignant phenotypes during radiotherapy of glioblastoma.

Truncation of MYH8 tail in AML: a novel prognostic marker with increase cell migration and epithelial-mesenchymal transition utilizing RAF/MAPK pathway

MYH8 is an actin-based motor protin involved in integrin-mediated cell adhesion and migration. Heretofore, the association of MYH8 mutation and cancer is unclear. In this study, we investigated the biologic significance of novel MYH8 tail truncation mutation, R1292X, in acute myeloid leukemia (AML) which was discovered by whole-exome sequencing and targeted re-sequencing of 209 AML patients. The patients harboring the mutation all relapsed within 3.8-20.9 months. To explore the functional consequence of the mutation in AML progress, we established knock-in cell lines using CRISPR-Cas9 genome editing. Using the established mutant model, we assessed traits of cancer progress. The mutant cells had improved motility, which was confirmed by immunofluorescence staining, wound healing, transwell migration and adhesion assay. The cell morphology and cell cycle were altered to be accessible to migration and epithelial-to-mesenchymal transition (EMT) transcription factors were also increased. The Raf and p44/42 MAPK pathway was a major regulator of these characteristics proved by a screening of signal transduction and inhibitor assay. Further, a public cancer genome database (cBioPortal) shows that MYH8 tail truncation mutations occurring near the R1292 position of the genome may have a significant function in cancer. In conclusion, truncation of MYH8 could be a novel prognostic marker related to poor prognosis by inducing cell migration and EMT features, and inhibition of the Raf/MAPK pathway would be a therapeutic strategy for AML patients with MYH8 tail truncation.

Influenza virus-mediated suppression of bronchial Chitinase-3-like 1 secretion promotes secondary pneumococcal infection

Infections of the lung are among the leading causes of death worldwide. Despite the preactivation of innate defense programs during viral infection, secondary bacterial infection substantially elevates morbidity and mortality rates. Particularly problematic are co-infections with influenza A virus (IAV) and the major bacterial pathogen Streptococcus pneumoniae. However, the molecular processes underlying the severe course of such co-infections are not fully understood. Previously, the absence of secreted glycoprotein Chitinase-3-like 1 (CHI3L1) was shown to increase pneumococcal replication in mice. We therefore hypothesized that an IAV preinfection decreases CHI3L1 levels to promote pneumococcal infection. Indeed, in an air-liquid interface model of primary human bronchial epithelial cells (hBECs), IAV preinfection interfered with apical but not basolateral CHI3L1 release. Confocal time-lapse microscopy revealed that the gradual loss of apical CHI3L1 localization during co-infection with influenza and S. pneumoniae coincided with the disappearance of goblet as well as ciliated cells and increased S. pneumoniae replication. Importantly, extracellular restoration of CHI3L1 levels using recombinant protein significantly reduced bacterial load in influenza preinfected bronchial models. Thus, recombinant CHI3L1 may provide a novel therapeutic means to lower morbidity and mortality associated with post-influenza pneumococcal infections.

Cellular and molecular events of inflammation induced transdifferentiation (EMT) and regeneration (MET) in mesenteric mesothelial cells

In this review we summarize the cellular and molecular events of inflammation induced epithelial-to-mesenchymal (EMT) and mesothelial-to-macrophage transition (MET) during regeneration. Since the receptor transmits the environmental stimulus, downregulating or upregulating the process on an epigenetic level, the intracellular localization of receptors (signaling organelles: early endosomes or lysosomal degradation: late endosomes) plays a crucial role in the signaling events regulating inflammation and regeneration. Therefore, we focused on the internalization of the receptors as well as the intracellular compartmentalization of signaling molecules during EMT and MET. The review draws the reader's attention to the plasticity of mesothelial cells and supports the idea that during inflammation an ambient macrophage population might derive from mesothelial cells.

DUSP4 directly deubiquitinates and stabilizes Smad4 protein, promoting proliferation and metastasis of colorectal cancer cells

Colorectal cancer is a common health-threatening tumor within the gastrointestinal tract. The aim of this study was to test the biological role of DUSP4 in colorectal cancer cells. In our study, DUSP4 overexpression-treated HCT116 cells and DUSP4 knockdown-treated SW480 cells were selected to perform study. Quantitative real-time PCR test (qRT-PCR) and western blot were used to detect DUSP4 abundance in clinical tissues and six cell lines, as well as ubiquitin-related Smad4 degradation. Western blot, migration and invasion. were used to assess the relationships between DUSP4 and Smad4. Higher DUSP4 expression of functional significance was observed in colorectal cancer tissues and cells. The results showed that both treatments could affect the proliferation, colony formation, migration, invasion of tumor cells, and the expression of epithelial mesenchymal transformation (EMT)-associated biomarkers. Moreover, in colorectal cancer cells, DUSP4 could promote the Smad4 degradation by regulating ubiquitin-related Smad4 degradation, and promote the cell proliferation, migration and invasion by regulating Smad4 degradation via Smad4 gene. Meanwhile, DUSP4 can directly deubiquitinate and stabilize Smad4 protein, hence further promote proliferation and metastasis of colorectal cancer cells.

DSTYK Promotes Metastasis and Chemoresistance via EMT in Colorectal Cancer

Objective

Tumor metastasis and resistance to chemotherapy are two critical factors that contribute to the high death rate of colorectal cancer (CRC) patients. Metastasis is facilitated by the epithelial-mesenchymal transition (EMT) of tumor cells, which has emerged not only as a fundamental process during metastasis, but is also a key process leading to chemoresistance of cancer cells. However, the underlying mechanisms of EMT in CRC cell remain unknown. Here, we aim to assess the role of dual serine/threonine and tyrosine protein kinase (DSTYK) in CRC metastasis and chemoresistance.

Methods

To study the role of DSTYK in TGF-β-induced EMT, we employed techniques including Crispr/Cas9 knockout (KO) to generate DSTYK KO cell lines, RT-PCR to detect the mRNA expression, immunofluorescence analyses, and western blots to detect protein levels of DSTYK in the following 4 cell lines: control LS411N-TβRII and LS411N-TβRII/DSTYK KO, control LS513 and LS513/DSTYK KO cells, treated with/without TGF-β. The effects of DSTYK on apoptosis were investigated by MTT assays, flow cytometry assays, and TUNEL assays. The expression of DSTYK in CRC patients and its correlation with EMT markers were determined by bioinformatics analysis. For in vivo analysis, both xenograft and orthotopic tumor mouse models were employed to investigate the function of DSTYK in chemoresistance and metastasis of tumors.

Results

In this study, we demonstrate that the novel kinase DSTYK promotes both TGF-β-induced EMT and the subsequent chemoresistance in CRC cells. DSTYK KO significantly attenuates TGF-β–induced EMT and chemoresistance in CRC cells. According to the Gene Expression Omnibus (GEO) database, the expression of DSTYK is not only positively correlated to the expression of TGF-β, but proportional to the death rate of CRC patients as well. Evidently, the expression of DSTYK in the metastatic colorectal cancer samples from patients was significantly higher than that of primary colorectal cancer samples. Further, we demonstrate in mouse models that chemotherapeutic drug treatment suppresses the growth of DSTYK KO tumors more effectively than control tumors.

Conclusion

Our findings identify DSTYK as a novel protein kinase in regulating TGF-β–mediated EMT and chemoresistance in CRC cells, which defines DSTYK as a potential therapeutic target for CRC therapy.

Targeting the TGFβ pathway in uterine carcinosarcoma

Uterine carcinosarcoma (UCS) is a relatively infrequent, but extremely aggressive endometrial malignancy. Although surgery and chemotherapy have improved outcomes, overall survival (OS) remains dismal due to the lack of targeted therapy and biphasic (epithelial and mesenchymal) nature that renders the tumor aggressive and difficult to manage. Here we report a role of transforming growth factor-β (TGFβ) in maintaining epithelial to mesenchymal transition (EMT) phenotype and aggressiveness in UCS. Using a 3D-culture system, we evaluated the efficacy of the transforming growth factor-β receptor-I (TGFβR1) kinase inhibitor Galunisertib (GLT), alone and in combination with standard chemotherapeutic drugs used for the management of UCS. We demonstrate that GLT by inhibiting canonical and non-canonical signaling emanating from transforming growth factor-β1 (TGFβ1) reduces cellular viability, invasion, clonal growth and differentiation. Interestingly, GLT sensitizes UCS cells to chemotherapy both in vitro and in in vivo preclinical tumor model. Hence, targeting TGFβ signaling, in combination with standard chemotherapy, may be exploited as an important strategy to manage the clinically challenging UCS.

The tumor microenvironment of colorectal cancer metastases: opportunities in cancer immunotherapy

About a fifth of individuals with colorectal cancer (CRC) present with disease metastasis at the time of diagnosis. While the role of the tumor microenvironment (TME) in governing CRC progression is undeniable, the role of the TME in either establishing or suppressing the formation of distant metastases of CRC is less well established. Despite advances in immunotherapy, many individuals with metastatic CRC do not respond to standard-of-care therapy. Therefore, understanding the role of the TME in establishing distant metastases is essential for developing new immunological agents. Here, we summarize our current understanding of the TME of CRC metastases, describe differences between the TME of primary tumors and their distant metastases, and discuss advances in the design and combinations of immunotherapeutic agents.

The oncogenic role of MUC12 in RCC progression depends on c-Jun/TGF-β signalling

Renal cell carcinoma (RCC) is a common kidney cancer worldwide. Even though current treatments show promising therapeutic effectiveness, metastatic RCC still has limited therapeutic options so that novel treatments were urgently needed. Here, we identified that MUC12 was overexpressed in RCC patients and served as poor prognostic factor for RCC progression. Overexpression of MUC12 increased RCC cell growth and cell invasion while deficiency of MUC12 exerted opposite effects on RCC cells. Mechanistic dissection demonstrated that MUC12-mediated RCC cell growth and cell invasion were dependent of TGF-β1 signalling because they could be blocked in the presence of TGF-β1 inhibitor. Moreover, the regulation of TGF-β1 by MUC12 relied on the transactivation of c-Jun. MUC12 promoted the recruitment of c-Jun on the promoter of TGF-β1, leading to its transcription. Importantly, knockdown of c-Jun also attenuated MUC12-mediated TGF-β1 induction and RCC cell invasion. In summary, our study defines the role of MUC12 in RCC progression and provides rational to develop novel targeted therapy to battle against RCC.

Natural alkaloid 8-oxo-epiberberine inhibited TGF-β1-triggred epithelial-mesenchymal transition by interfering Smad3

Epithelial-mesenchymal transition (EMT), the transition of epithelial cells into mesenchymal cells, plays important roles in the metastasis of solid tumors. 8-Oxo-epiberberine (OPB) is a natural alkaloid extracted from the roots of Coptis chinensis Franch. In this study, The effect and the underlying mechanism of OPB on EMT in a TGF-β1-induced model and the inhibitory effect of OPB on lung metastasis were investigated. TGF-β1-stimulated lung cancer cells were co-treated with OPB, the morphological changes were examined. The protein expression of EMT biomarkers E-cadherin and N-cadherin was determined by Western blotting and immunofluorescence. The transcription activity of smad2/3 promoter was analyzed by a luciferase reporter assay. The effect of OPB on cell migration, invasion, and adhesion was detected by wound-healing, adhesion, and transwell assays. The in vivo anti-metastatic effect of OPB was evaluated using a 4 T1 cell xenograft mouse model. Results showed that OPB significantly reversed TGF-β1-triggered morphological changes, expression of EMT biomarkers, and migration, adhesion, and invasion. Furthermore, OPB suppressed TGF-β1-induced Smad2/3 activation, Smad3 phosphorylation and nuclear translocation, and interaction of Smad3 with Smad4. Besides, OPB dramatically decreased the metastatic nodules in the lung without affecting the growth of primary tumors. In conclusion, OPB inhibited TGF-β1-induced EMT possibly by interfering with Smad3. OPB might have therapeutic potentials for the treatment of metastatic cancers.

Aspirin inhibits TGFβ2-induced epithelial to mesenchymal transition of lens epithelial cells: selective acetylation of K56 and K122 in histone H3

Posterior capsule opacification (PCO) is a complication after cataract surgery that can disrupt vision. The epithelial to mesenchymal transition (EMT) of lens epithelial cells (LECs) in response to transforming growth factor β2 (TGFβ2) has been considered an obligatory mechanism for PCO. In this study, we tested the efficacy of aspirin in inhibiting the TGFβ2-mediated EMT of human LECs, LECs in human lens capsular bags, and lensectomized mice. In human LECs, the levels of the EMT markers α-smooth muscle actin (α-SMA) and fibronectin were drastically reduced by treatment with 2 mM aspirin. Aspirin also halted the EMT response of TGFβ2 when introduced after EMT initiation. In human capsular bags, treatment with 2 mM aspirin significantly suppressed posterior capsule wrinkling and the expression α-SMA in capsule-adherent LECs. The inhibition of TGFβ2-mediated EMT in human LECs was not dependent on Smad phosphorylation or MAPK and AKT-mediated signaling. We found that aspirin significantly increased the acetylation of K56 and K122 in histone H3 of human LECs. Chromatin immunoprecipitation assays using acetyl-H3K56 or acetyl-H3K122 antibody revealed that aspirin blocked the TGFβ2-induced acetylation of H3K56 and H3K122 at the promoter regions of ACTA2 and COL1A1. After lensectomy in mice, we observed an increase in the proliferation and α-SMA expression of the capsule-adherent LECs, which was ameliorated by aspirin administration through drinking water. Taken together, our results showed that aspirin inhibits TGFβ2-mediated EMT of LECs, possibly from epigenetic down-regulation of EMT-related genes.

Epithelial-Mesenchymal Transition Programs and Cancer Stem Cell Phenotypes: Mediators of Breast Cancer Therapy Resistance

Epithelial-mesenchymal transition (EMT) programs play essential functions in normal morphogenesis and organogenesis, including that occurring during mammary gland development and glandular regeneration. Historically, EMT programs were believed to reflect a loss of epithelial gene expression signatures and morphologies that give way to those associated with mesenchymal cells and their enhanced migratory and invasive behaviors. However, accumulating evidence now paints EMT programs as representing a spectrum of phenotypic behaviors that also serve to enhance cell survival, immune tolerance, and perhaps even metastatic dormancy. Equally important, the activation of EMT programs in transformed mammary epithelial cells not only enhances their acquisition of invasive and metastatic behaviors, but also expands their generation of chemoresistant breast cancer stem cells (BCSC). Importantly, the net effect of these events results in the appearance of recurrent metastatic lesions that remain refractory to the armamentarium of chemotherapies and targeted therapeutic agents deployed against advanced stage breast cancers. Here we review the molecular and cellular mechanisms that contribute to the pathophysiology of EMT programs in human breast cancers and how these events impact their "stemness" and acquisition of chemoresistant phenotypes.

TGFβ1-Smad canonical and -Erk noncanonical pathways participate in interleukin-17-induced epithelial-mesenchymal transition in Sjögren's syndrome

Interleukin-17 (IL-17) is a pleiotropic cytokine that plays a primary role in triggering epithelial-mesenchymal transition (EMT) in many chronic inflammatory diseases. EMT plays a critical role in the progression of salivary gland (SG) fibrosis in primary Sjögren's syndrome (pSS). This study focused on the activation of the canonical TGF-β1/Smad2/3 and noncanonical TGF-β1/Erk1/2 pathways in IL-17-dependent TGFβ1-induced EMT in human SG epithelial cells (SGEC) derived from healthy subjects. The expression of phosphorylated Smad2/3 and Erk1/2 during IL-17 treatment-stimulated EMT was evaluated in healthy SGEC. Cotreatment with IL-17 and specific TGFβ receptor type I kinase inhibitor SB431542, or Erk 1/2 inhibitor U0126, abrogates the corresponding morphological changes and EMT phenotypic markers expression in healthy SGEC. Interestingly, inhibition of canonical TGFβ1/Smad2/3 signal transduction had no effect on activation of the noncanonical TGFβ1/Erk1/2/EMT pathway, suggesting that the two pathways act independently in activating IL-17-dependent EMT in SGEC.

Single-Cell Transcriptomic Analysis of Tumor-Derived Fibroblasts and Normal Tissue-Resident Fibroblasts Reveals Fibroblast Heterogeneity in Breast Cancer

Cancer-associated fibroblasts (CAFs) are a prominent stromal cell type in solid tumors and molecules secreted by CAFs play an important role in tumor progression and metastasis. CAFs coexist as heterogeneous populations with potentially different biological functions. Although CAFs are a major component of the breast cancer stroma, molecular and phenotypic heterogeneity of CAFs in breast cancer is poorly understood. In this study, we investigated CAF heterogeneity in triple-negative breast cancer (TNBC) using a syngeneic mouse model, BALB/c-derived 4T1 mammary tumors. Using single-cell RNA sequencing (scRNA-seq), we identified six CAF subpopulations in 4T1 tumors including: 1) myofibroblastic CAFs, enriched for α-smooth muscle actin and several other contractile proteins; 2) ‘inflammatory’ CAFs with elevated expression of inflammatory cytokines; and 3) a CAF subpopulation expressing major histocompatibility complex (MHC) class II proteins that are generally expressed in antigen-presenting cells. Comparison of 4T1-derived CAFs to CAFs from pancreatic cancer revealed that these three CAF subpopulations exist in both tumor types. Interestingly, cells with inflammatory and MHC class II-expressing CAF profiles were also detected in normal breast/pancreas tissue, suggesting that these phenotypes are not tumor microenvironment-induced. This work enhances our understanding of CAF heterogeneity, and specifically targeting these CAF subpopulations could be an effective therapeutic approach for treating highly aggressive TNBCs.

LINC00261 Is Differentially Expressed in Pancreatic Cancer Subtypes and Regulates a Pro-Epithelial Cell Identity

Pancreatic adenocarcinoma (PDAC) is one of the major causes of cancer-associated deaths worldwide, with a dismal prognosis that has not significantly changed over the last decades. Transcriptional analysis has provided valuable insights into pancreatic tumorigenesis. Specifically, pancreatic cancer subtypes were identified, characterized by specific mutations and gene expression changes associated with differences in patient survival. In addition to differentially regulated mRNAs, non-coding RNAs, including long non-coding RNAs (lncRNAs), were shown to have subtype-specific expression patterns. Hence, we aimed to characterize prognostic lncRNAs with deregulated expression in the squamous subtype of PDAC, which has the worst prognosis. Extensive in silico analyses followed by in vitro experiments identified long intergenic non-coding RNA 261 (LINC00261) as a downregulated lncRNA in the squamous subtype of PDAC, which is generally associated with transforming growth factor β (TGFβ) signaling in human cancer cells. Its genomic neighbor, the transcription factor forkhead box protein A2 (FOXA2), regulated LINC00261 expression by direct binding of the LINC00261 promoter. CRISPR-mediated knockdown and promoter knockout validated the importance of LINC00261 in TGFβ-mediated epithelial–mesenchymal transition (EMT) and established the epithelial marker E-cadherin, an important cell adhesion protein, as a downstream target of LINC00261. Consequently, depletion of LINC00261 enhanced motility and invasiveness of PANC-1 cells in vitro. Altogether, our data suggest that LINC00261 is an important tumor-suppressive lncRNA in PDAC that is involved in maintaining a pro-epithelial state associated with favorable disease outcome.

Cellular Plasticity in Breast Cancer Progression and Therapy

With the exception of non-melanoma skin cancer, breast cancer is the most frequently diagnosed malignant disease among women, with the majority of mortality being attributable to metastatic disease. Thus, even with improved early screening and more targeted treatments which may enable better detection and control of early disease progression, metastatic disease remains a significant problem. While targeted therapies exist for breast cancer patients with particular subtypes of the disease (Her2+ and ER/PR+), even in these subtypes the therapies are often not efficacious once the patient's tumor metastasizes. Increases in stemness or epithelial-to-mesenchymal transition (EMT) in primary breast cancer cells lead to enhanced plasticity, enabling tumor progression, therapeutic resistance, and distant metastatic spread. Numerous signaling pathways, including MAPK, PI3K, STAT3, Wnt, Hedgehog, and Notch, amongst others, play a critical role in maintaining cell plasticity in breast cancer. Understanding the cellular and molecular mechanisms that regulate breast cancer cell plasticity is essential for understanding the biology of breast cancer progression and for developing novel and more effective therapeutic strategies for targeting metastatic disease. In this review we summarize relevant literature on mechanisms associated with breast cancer plasticity, tumor progression, and drug resistance.

Mechanotactic Activation of TGF-β by PEDOT Artificial Microenvironments Triggers Epithelial to Mesenchymal Transition

Epithelial to mesenchymal transition (EMT) is integral for cells to acquire metastatic properties, and ample evidence links it to bioorganic framework of the tumor microenvironment (TME). Hydroxymethyl-functionalized 3,4-ethylenedioxythiophene polymer (PEDOT-OH) enables construction of diverse nanotopography size and morphologies and is therefore exploited to engineer organic artificial microenvironments bearing nanodots from 300 to 1000 nm in diameter to understand spatiotemporal EMT regulation by biophysical components of the TME. MCF-7 breast cancer cells are cultured on these artificial microenvironments, and temporal regulation of cellular morphology and EMT markers is investigated. The results show that upon physical stimulation, cells on 300 nm artificial microenvironments advance to EMT and display a decreased extracellular matrix (ECM) protein secretion. In contrast, cells on 500 nm artificial microenvironments are trapped in EMT-imbalance. Interestingly, cells on 1000 nm artificial microenvironments resemble those on control surfaces. Upon further investigation, it is found that EMT induction is triggered via transforming growth factor β (TGF-β) and ECM cleaving protein, matrix metalloproteinease-9. Immunostaining EMT proteins highlighted that EMT induction is achieved through attenuation of cell-cell and cell-microenvironment adhesions. The physical stimulation-induced TGF-β perturbation can have a profound impact on the understanding of tumor-promoting signaling cascades originated by cellular microenvironment.

Circulating TGF-β1 as the potential epithelial mesenchymal transition-biomarker for diagnosis of cholangiocarcinoma

Background

Cholangiocarcinoma (CCA) is a malignant tumor arising from bile duct epithelium. The oncogenic risk factor is infection by the liver fluke, Opisthorchis viverrini (Ov). One of key mechanism in the development of CCA is epithelial mesenchymal transition (EMT). We aimed to investigate the expression of EMT-related proteins namely, E-cadherin, TGF-β1 and BMP-7 in CCA tissues, to determine the level of candidate EMT-related protein, and to examine whether there were significant correlations with clinicopathological data in sera of CCA patients compared with normal groups.

Methods

The expression of E-cadherin, TGF-β1 and BMP-7 was analyzed in human CCA tissues by immunohistochemistry and altered expressions compared to clinicopathological data were analyzed to identify the potential candidate EMT-biomarker. Subsequently, the level of candidate marker was determined in sera of CCA patients compared with normal and inflammatory-related diseases groups by enzyme-linked immunosorbent assay (ELISA).

Results

Immunohistochemical analysis showed that E-cadherin was expressed at a low level whereas TGF-β1 and BMP-7 showed high expression in CCA tissues when compared with liver from cadaveric donor. Interestingly, only high TGF-β1 expression in CCA tissues was significantly correlated with lymph node metastasis, severe cancer stage, intrahepatic CCA type and shorter survival time of CCA patients (P<0.05). Consequently, TGF-β1 was selected to determine the level in serum of CCA patients using ELISA. The results showed that serum TGF-β1 level was elevated in CCA patients compared to the normal group. Patients with high TGF-β1 levels were significantly correlated with metastasis status (P=0.03). Furthermore, receiver operating characteristic (ROC) analysis showed that serum TGF-β1 level is effective in distinguishing CCA patients from normal at the cut-off of 38.54 ng/mL with high sensitivity (71.1%) and specificity (68.9%) and from inflammatory-related diseases group at the cut-off of 38.67 ng/mL with effective sensitivity (68.0%) and specificity (71.1%). Furthermore, TGF-β1 could serve as a novel metastatic biomarker in CCA to diagnose the disease with 48.95 ng/mL as the cut-off along with the desired sensitivity and specificity (48.2% and 88.9% respectively).

Conclusions

The results of this study show that TGF-β1 could be a potential EMT-biomarker for diagnosis and prognosis of CCA.

Tracking Drug-Induced Epithelial-Mesenchymal Transition in Breast Cancer by a Microfluidic Surface-Enhanced Raman Spectroscopy Immunoassay

Epithelial-mesenchymal transition (EMT) is a primary mechanism for cancer metastasis. Detecting the activation of EMT can potentially convey signs of metastasis to guide treatment management and improve patient survival. One of the classic signatures of EMT is characterized by dynamic changes in cellular expression levels of E-cadherin and N-cadherin, whose soluble active fragments have recently been reported to be biomarkers for cancer diagnosis and prognosis. Herein, a microfluidic immunoassay (termed "SERS immunoassay") based on sensitive and simultaneous detection of soluble E-cadherin (sE-cadherin) and soluble N-cadherin (sN-cadherin) for EMT monitoring in patients' plasma is presented. The SERS immunoassay integrates in situ nanomixing and surface-enhanced Raman scattering readout to enable accurate detection of sE-cadherin and sN-cadherin from as low as 10 cells mL^-1 . This assay enables tracking of a concurrent decrease in sE-cadherin and increase in sN-cadherin in breast cancer cells undergoing drug-induced mesenchymal transformation. The clinical potential of the SERS immunoassay is further demonstrated by successful detection of sE-cadherin and sN-cadherin in metastatic stage IV breast cancer patient plasma samples. The SERS immunoassay can potentially sense the activation of EMT to provide early indications of cancer invasions or metastasis.

Fluidity of Poly (ε-Caprolactone)-Based Material Induces Epithelial-to-Mesenchymal Transition

BACKGROUND

We propose the potential studies on material fluidity to induce epithelial to mesenchymal transition (EMT) in MCF-7 cells. In this study, we examined for the first time the effect of material fluidity on EMT using poly(ε-caprolactone-co-D,L-lactide) (P(CL-co-DLLA)) with tunable elasticity and fluidity.

METHODS

The fluidity was altered by chemically crosslinking the polymer networks. The crosslinked P(CL-co-DLLA) substrate showed a solid-like property with a stiffness of 261 kPa, while the non-crosslinked P(CL-co-DLLA) substrate of 100 units (high fluidity) and 500 units (low fluidity) existed in a quasi-liquid state with loss modulus of 33 kPa and 30.8 kPa, respectively, and storage modulus of 10.8 kPa and 20.1 kPa, respectively.

RESULTS

We observed that MCF-7 cells on low fluidic substrates decreased the expression of E-cadherin, an epithelial marker, and increased expression of vimentin, a mesenchymal marker. This showed that the cells lose their epithelial phenotype and gain a mesenchymal property. On the other hand, MCF-7 cells on high fluidic substrates maintained their epithelial phenotype, suggesting that the cells did not undergo EMT.

CONCLUSION

Considering these results as the fundamental information for material fluidity induced EMT, our system could be used to regulate the degree of EMT by turning the fluidity of the material.

TGF-β in radiotherapy: Mechanisms of tumor resistance and normal tissues injury

Emerging evidences show that changes in tumor stroma can adapt cancer cells to radiotherapy, thereby leading to a reduction in tumor response to treatment. On the other hand, radiotherapy is associated with severe reactions in normal tissues which limit the amount radiation dose received by tumor. These challenges open a window in radiobiology and radiation oncology to explore mechanisms for improving tumor response and also alleviate side effects of radiotherapy. Transforming growth factor beta (TGF-β) is a well-known and multitasking cytokine that regulates a wide range of reactions and interactions within tumor and normal tissues. Within tumor microenvironment (TME), TGF-β is the most potent suppressor of immune system activity against cancer cells. This effect is mediated through stimulation of CD4+ which differentiates to T regulatory cells (Tregs), infiltration of fibroblasts and differentiation into cancer associated fibroblasts (CAFs), and also polarization of macrophages to M2 cells. These changes lead to suppression of cytotoxic CD8 + T lymphocytes (CTLs) and natural killer (NK) cells to kill cancer cells. TGF-β also plays a key role in the angiogenesis, invasion and DNA damage responses (DDR) in cancer cells. In normal tissues, TGF-β triggers the expression of a wide range of pro-oxidant and pro-fibrosis genes, leading to fibrosis, genomic instability and some other side effects. These properties of TGF-β make it a potential target to preserve normal tissues and sensitize tumor via its inhibition. In the current review, we aim to explain the mechanisms of upregulation of TGF-β and its consequences in both tumor and normal tissues.

Role of TGF-β in Skin Chronic Wounds: A Keratinocyte Perspective

Chronic wounds are characterized for their incapacity to heal within an expected time frame. Potential mechanisms driving this impairment are poorly understood and current hypotheses point to the development of an unbalanced milieu of growth factor and cytokines. Among them, TGF-β is considered to promote the broadest spectrum of effects. Although it is known to contribute to healthy skin homeostasis, the highly context-dependent nature of TGF-β signaling restricts the understanding of its roles in healing and wound chronification. Historically, low TGF-β levels have been suggested as a pattern in chronic wounds. However, a revision of the available evidence in humans indicates that this could constitute a questionable argument. Thus, in chronic wounds, divergences regarding skin tissue compartments seem to be characterized by elevated TGF-β levels only in the epidermis. Understanding how this aspect affects keratinocyte activities and their capacity to re-epithelialize might offer an opportunity to gain comprehensive knowledge of the involvement of TGF-β in chronic wounds. In this review, we compile existing evidence on the roles played by TGF-β during skin wound healing, with special emphasis on keratinocyte responses. Current limitations and future perspectives of TGF-β research in chronic wounds are discussed.

Mechanisms of Herbal Nephroprotection in diabetes mellitus

Diabetic nephropathy (DN) is a leading cause of kidney morbidity. Despite the multilayered complexity of the mechanisms involved in the pathogenesis of DN, the conventional treatment is limited to just a few drug classes fraught with the risk of adverse events, including the progression of renal dysfunction. Phytoceuticals offer a promising alternative as they act on the many-sidedness of DN pathophysiology, multitargeting its intricacies. This paper offers a review of the mechanisms underlying the protective action of these phytoagents, including boosting the antioxidant capabilities, suppression of inflammation, averting the proliferative and sclerosing/fibrosing events. The pathogenesis of DN is viewed as a continuum going from the original offense, high glucose, through the noxious products it generates (advanced glycation end-products, products of oxidative and nitrosative stress) and the signaling chains consequently brought into action, to the harmful mediators of inflammation, sclerosis, and proliferation that eventually lead to DN, despite the countervailing attempts of the protective mechanisms. Special attention was given to the various pathways involved, pointing out the ability of the phytoagents to hinder the deleterious ones (especially those leading to, driven by, or associated with TGF-β activation, SREBP, Smad, MAPK, PKC, NF-κB, NLRP3 inflammasome, and caspase), to promote the protective ones (PPAR-α, PPAR-γ, EP4/Gs/AC/cAMP, Nrf2, AMPK, and SIRT1), and to favorably modulate those with potentially dual effect (PI3K/Akt). Many phytomedicines have emerged as potentially useful out of in vitro and in vivo studies, but the scarcity of human trials seriously undermines their usage in the current clinical practice-an issue that stringently needs to be addressed.

Tanshinone IIA reverses EGF- and TGF-β1-mediated epithelial-mesenchymal transition in HepG2 cells via the PI3K/Akt/ERK signaling pathway

Epithelial-to-mesenchymal transition (EMT) is an essential phenotypic conversion involved in cancer progression. Epidermal growth factor (EGF) and transforming growth factor (TGF)-β1 are potent inducers of the EMT. Tanshinone IIA (Tan IIA) is a phenanthrenequinone extracted from the root of Salvia miltiorrhiza Bunge, and its anticancer activity has been demonstrated in numerous studies. However, the mechanisms of action underlying Tan IIA in EGF- and TGF-β1-induced EMT in HepG2 cells remain unknown. Multiple assays were utilized in the present study, including colony formation, wound healing, Transwell invasion, immunofluorescence staining and western blotting, in order to assess the influence of Tan IIA on HepG2 cells induced by 20 ng/ml EGF and 10 ng/ml TGF-β1. The present study reported that Tan IIA treatment decreased EGF- and TGF-β1-enhanced cell colony numbers, migration and invasion, and inhibited EGF- and TGF-β1-induced decreases in the expression levels of E-cadherin, and increases in the expression levels of matrix metalloproteinase-2, N-cadherin, vimentin and Snail. In addition, it was observed that Tan IIA decreased the expression levels of phosphorylated (p)-Akt and p-ERK1/2 induced by EGF and TGF-β1. Furthermore, western blot analysis confirmed that blocking the function of PI3K/Akt and ERK with LY294002 and U0126 resulted in upregulation of E-cadherin expression, and downregulation of vimentin and Snail expression in EGF- and TGF-β1-treated HepG2 cells. In conclusion, to the best of our knowledge, the results of the present study are the first to indicate that Tan IIA may suppress EGF- and TGF-β1-induced EMT in HepG2 cells by deactivating the PI3K/Akt/ERK pathway.

Effect of Nigella sativa and its bioactive compound on type 2 epithelial to mesenchymal transition: a systematic review

BACKGROUND

Nigella sativa or commonly known as black seed or black cumin is one of the most ubiquitous complementary medicine. Epithelial to mesenchymal transition (EMT) of type 2 is defined by the balance between wound healing and tissue fibrosis, which is dependent to the state of inflammation. This systematic review is conducted to provide an overview regarding the reported effect of Nigella sativa and its bioactive compound on the type 2 EMT.

METHODS

A search was done in EBSCOHOST, OVID and SCOPUS database to obtain potentially relevant articles that were published between 1823 and August 2019. This review includes studies that focus on the effect of Nigella sativa and its bioactive compound on the events related to type 2 EMT.

RESULTS

A total of 1393 research articles were found to be potentially related to the effect of Nigella sativa and its bioactive compound, thymoquinone on Type 2 EMT. After screening was done, 22 research articles met inclusion criteria and were included in this review. Majority of the studies, reported better wound healing rate or significant prevention of tissue inflammation and organ fibrosis following Nigella sativa or thymoquinone treatments. In terms of wound healing, studies included reported progression of EMT related pathological changes after treatment with Nigella sativa or thymoquinone. Alternatively, in terms of fibrosis and inflammation, studies included reported reversal of pathological changes related to EMT after treatment with Nigella sativa or thymoquinone.

CONCLUSION

Through this review, Nigella sativa and thymoquinone have been associated with events in Type 2 EMT. They have been shown to promote wound healing, attenuate tissue inflammation, and prevent organ fibrosis via regulation of the EMT process.

The Molecular Mechanism of Epithelial-Mesenchymal Transition for Breast Carcinogenesis

The transforming growth factor-β (TGF-β) signaling pathway plays multiple regulatory roles in the tumorigenesis and development of cancer. TGF-β can inhibit the growth and proliferation of epithelial cells and induce apoptosis, thereby playing a role in inhibiting breast cancer. Therefore, the loss of response in epithelial cells that leads to the inhibition of cell proliferation due to TGF-β is a landmark event in tumorigenesis. As tumors progress, TGF-β can promote tumor cell invasion, metastasis, and drug resistance. At present, the above-mentioned role of TGF-β is related to the interaction of multiple signaling pathways in the cell, which can attenuate or abolish the inhibition of proliferation and apoptosis-promoting effects of TGF-β and enhance its promotion of tumor progression. This article focuses on the molecular mechanisms through which TGF-β interacts with multiple intracellular signaling pathways in tumor progression and the effects of these interactions on tumorigenesis.

Presence of Stromal Cells Enhances Epithelial-to-Mesenchymal Transition (EMT) Induction in Lung Bronchial Epithelium after Protracted Exposure to Oxidative Stress of Gamma Radiation

The aim of the study was to investigate the role of a microenvironment in the induction of epithelial-to-mesenchymal transition (EMT) as a sign of early stages of carcinogenesis in human lung epithelial cell lines after protracted low-dose rate γ-radiation exposures. BEAS-2B and HBEC-3KT lung cell lines were irradiated with low-dose rate γ-rays (¹³⁷Cs, 1.4 or 14 mGy/h) to 0.1 or 1 Gy with or without adding TGF-β. TGF-β-treated samples were applied as positive EMT controls and tested in parallel to find out if the radiation has a potentiating effect on the EMT induction. To evaluate the effect of the stromal component, the epithelial cells were irradiated in cocultures with stromal MRC-9 lung fibroblasts. On day 3 post treatment, the EMT markers: α-SMA, vimentin, fibronectin, and E-cadherin, were analyzed. The oxidative stress levels were evaluated by 8-oxo-dG analysis in both epithelial and fibroblast cells. The protracted exposure to low Linear Energy Transfer (LET) radiation at the total absorbed dose of 1 Gy was able to induce changes suggestive of EMT. The results show that the presence of the stromal component and its signaling (TGF-β) in the cocultures enhances the EMT. Radiation had a minor cumulative effect on the TGF-β-induced EMT with both doses. The oxidative stress levels were higher than the background in both epithelial and stromal cells post chronic irradiation (0.1 and 1 Gy); as for the BEAS-2B cell line, the increase was statistically significant. We suggest that the induction of EMT in bronchial epithelial cells by radiation requires more than single acute exposure and the presence of stromal component might enhance the effect through free radical production and accumulation.

Clinical, pathological and prognostic implications of USP22, SIRT1 and E-cadherin expression in papillary thyroid cancer (PTC) and adjacent non-neoplastic tissue

Introduction

Ubiquitin-specific peptidase 22 (USP22) is described as a stem cell (CSC) marker which is involved in many biological processes, including cancer development, cellular growth and differentiation. Sirtuin 1 (SIRT1) controls a set of biologic processes that range from metabolic homeostasis to cancer. E-cadherin is a calcium-dependent intercellular adhesion molecule. Clinically, USP22, SIRT1 and E-cadherin have been studied to predict prognosis of a variety of cancers but the detailed roles of their expression in papillary thyroid cancer (PTC) and their relation to cancer invasion, metastases and recurrence are still not fully explained.

Aim of the study

To evaluate the expression of USP22, SIRT1 & E-cadherin in PTC tissues and adjacent non-neoplastic thyroid tissue and to correlate their expression with histopathology, clinical, pathological and prognostic parameters of PTC patients.

Methods

We have assessed USP22, SIRT1 & E-cadherin expression using immunohistochemistry in 40 cases with PTC in both malignant tissue and adjacent non-neoplastic tissue, analyzed the relationships between their levels of expression, clinic-pathological parameters, prognosis and survival of patients.

Results

High protein expression levels of both USP22, SIRT1 in addition to low E-cadherin expression in PTC were associated with larger tumors, extra-thyroidal extension, vascular invasion, lymphatic spread (p < 0.001), existence of distant metastases (p = 0.005 & 0.012 respectively), higher stage of the disease (p = 0.012 & 0.042 respectively) and worse five-years overall survival rates (p < 0.001).

Conclusion

Patients having advanced PTC with unfavorable prognosis had high levels of both USP22, SIRT1 in addition to low E-cadherin expression.

Autophagy inhibition elicits emergence from metastatic dormancy by inducing and stabilizing Pfkfb3 expression

Breast cancer stem cells (BCSCs) are unique in their ability to undergo unlimited self-renewal, an essential process in breast cancer recurrence following metastatic dormancy. Emergent metastatic lesions were subjected to microarray analysis, which identified 6-phosphofructo-2-kinase/fructose-2,6-biphosphatase 3 (Pfkfb3) as a differentially expressed gene coupled to metastatic recurrence. Here, we report that elevated Pfkfb3 expression correlates with the appearance of aggressive breast cancers and reduces relapse-free survival, as well as enhances BCSC self-renewal and metastatic outgrowth. We observe an inverse relationship between Pfkfb3 expression and autophagy, which reduces Pfkfb3 expression and elicits cellular dormancy. Targeted depletion of Atg3, Atg7, or p62/sequestosome-1 to inactivate autophagy restores aberrant Pfkfb3 expression in dormant BCSCs, leading to their reactivation of proliferative programs and outgrowth. Moreover, Pfkfb3 interacts physically with autophagy machinery, specifically the UBA domain of p62/sequestosome-1. Importantly, disrupting autophagy and this event enables Pfkfb3 to drive dormant BCSCs and metastatic lesions to recur.

Deciphering Hydrodynamic and Drug-Resistant Behaviors of Metastatic EMT Breast Cancer Cells Moving in a Constricted Microcapillary

Epithelial to mesenchymal transition (EMT) induces cell migration, invasion, and drug resistance, and consequently, contributes to cancer metastasis and disease aggressiveness. This study attempted to address crucial biological parameters to correlate EMT and drug-treated cancer cells traversing through microcapillaries, reminiscent of metastatic conditions. MDA-MB-468 breast cancer cells induced to undergo EMT by treatment with 20 ng/mL of epidermal growth factor (EGF) were initially passed through several blockages and then through a constricted microchannel, mimicking the flow of invasive metastatic cells through constricted blood microcapillaries. EMT cells acquired enhanced migratory properties and retained 50% viability, even after migration through wells 10-15 μm in size and a constricted passage of 7 μm and 150 μm in length at a constant flow rate of 50 μL/h. The hydrodynamic properties revealed cellular deformation with a deformation index, average transit velocity, and entry time of 2.45, 12.3 mm/s, and 31,000 μs, respectively for a cell of average diameter 19 μm passing through one of the 7 μm constricted sections. Interestingly, cells collected at the channel outlet regained epithelial character, undergoing reverse transition (mesenchymal to epithelial transition, MET) in the absence of EGF. Remarkably, real-time polymerase chain reaction (PCR) analysis confirmed increases of 2- and 2.7-fold in the vimentin and fibronectin expression in EMT cells, respectively; however, their expression reduced to basal level in the MET cells. A scratch assay revealed the pronounced migratory nature of EMT cells compared with MET cells. Furthermore, the number of colonies formed from EMT cells and paclitaxel-treated EMT cells after passing through a constriction were found to be 95 ± 10 and 79 ± 4, respectively, confirming that the EMT cells were more drug resistant with a concomitant two-fold higher expression of the multi-drug resistance (MDR1) gene. Our results highlight the hydrodynamic and drug-evading properties of cells that have undergone an EMT, when passed through a constricted microcapillary that mimics their journey in blood circulation.

The Activation Status of the TGF-β Transducer Smad2 Is Associated with a Reduced Survival in Gastrointestinal Cancers: A Systematic Review and Meta-Analysis

Aberrant function of Smad2, a crucial member of transforming growth factor beta (TGF-β) signaling, is associated with the development of malignancies, particularly in the gastrointestinal district. However, little is known about its possible prognostic role in such tumor types. With the first meta-analysis on this topic, we demonstrated that the lack of the activated form of Smad2 (phosphor-Smad2 or pSmad2), which was meant to be the C-terminally phosphorylated form, showed a statistically significant association with an increased risk of all-cause mortality in patients with gastrointestinal cancers (RR, 1.58; 95% CI, 1.05–2.37, p = 0.029, I² = 84%), also after having adjusted for potential confounders (RR, 1.65; 95% CI, 1.24–2.18; p < 0.001; I² = 4%). This finding highlights the importance of the TGF-β signaling in this type of cancer. In this line, further studies are needed to explore more in depth this important molecular pathway, focusing also on potential therapeutic strategies based on its effectors or molecular targets.

Novel transforming growth factor beta receptor I kinase inhibitor galunisertib (LY2157299) in advanced hepatocellular carcinoma

BACKGROUND AND AIMS

We assessed the activity of galunisertib, a small molecule inhibitor of the transforming growth factor beta (TGF-β1) receptor I, in second-line patients with hepatocellular carcinoma (HCC) in two cohorts of baseline serum alpha fetoprotein (AFP).

METHODS

Patients with advanced HCC who progressed on or were ineligible to receive sorafenib, Child-Pugh A/B7 and ECOG PS ≤1 were enrolled into Part A (AFP ≥ 1.5× ULN) or Part B (AFP < 1.5× ULN). Patients were treated with 80 or 150 mg galunisertib BID for 14 days per 28-day cycle. Endpoints were time-to-progression (TTP) and changes in circulating AFP and TGF-β1 levels, as well as safety, pharmacokinetics, progression-free survival and overall survival (OS).

RESULTS

Patients (n = 149) were enrolled with median age 65 years. Median TTP was 2.7 months (95% CI: 1.5-2.9) in Part A (n = 109) and 4.2 months (95% CI: 1.7-5.5) in Part B (n = 40). Median OS was 7.3 months (95% CI: 4.9-10.5) in Part A and 16.8 months (95% CI: 10.5-24.4) in Part B. OS was longer in AFP responders (>20% decrease from baseline, Part A) compared to non-responders (21.5 months vs 6.8 months). OS was longer in TGF-β1 responders (>20% decrease from baseline, all patients) compared to non-responders. The most common Grade 3/4 treatment-related adverse events were neutropenia (n = 4) and fatigue, anaemia, increased bilirubin, hypoalbuminemia and embolism (each, n = 2).

CONCLUSIONS

Galunisertib treatment had a manageable safety profile in patients with HCC. Lower baseline AFP and a response in AFP or TGF-β1 levels (vs no response) correlated with longer survival.

TRIAL REGISTRATION NUMBER

NCT01246986 at ClinicalTrials.gov.

Schisandrin B inhibits TGF-β1-induced epithelial-mesenchymal transition in human A549 cells through epigenetic silencing of ZEB1

Purpose/Aim: More and more evidences suggest that airway remodeling of fibrotic lung diseases may be associated with epithelial-mesenchymal transition (EMT) of human A549 cells induced by transforming growth factor (TGF)-β1. Schisandrin B (Sch B) is the highest content of dibenzocyclooctadiene lignans in Schisandra chinensis. In this study, we assessed the inhibitory influences of Sch B on TGF-β1-stimulated EMT in human A549 cells. Materials and Methods: The influences of Sch B on cell viability, invasion and metastasis in TGF-β1-induced human A549 cells were detected by MTT, wound healing and transwell invasion assays. The expression levels of α-SMA, E-cadherin, ZEB1 and Twist1 were examined by quantitative reverse transcription polymerase chain reaction (qRT-PCR) and western blot. The enrichment of H3K4me3 and H3K9me3 at the ZEB1 promoter was determined by ChIP analysis. Results: Experimental results showed that Sch B increased the expression of the epithelial phenotype marker E-cadherin and inhibited the expression of the mesenchymal phenotype marker α-SMA during EMT induced by TGF-β1. The enhancement in invasion and migration of TGF-β1-induced A549 cells was inhibited by Sch B. Sch B also repressed the expression of ZEB1 transcription factor in EMT, by increasing the enrichment of H3K9me3 at the ZEB1 promoter to repress its transcription while the expression of the Twist1 transcription factor was unaffected. Conclusions: Our data suggest that Sch B can prevent TGF-β1-stimulated EMT in A549 cells through epigenetic silencing of ZEB1, which may be clinically related to the efficient treatment of EMT-associated fibrotic diseases.