EMT: 2016. Cell. 2016;166:21-45. [PMID: 27368099 DOI: 10.1016/j.cell.2016.06.028]

Pim-3 enhances melanoma cell migration and invasion by promoting STAT3 phosphorylation

Melanoma is the deadliest form of commonly encountered skin cancer, and has fast propagating and highly invasive characteristics. Pim-3, a highly expressed oncogene in melanoma, is a highly conserved serine/threonine kinase with various biological activities, such as proliferation-accelerating and anti-apoptosis effects on cancer progression. However, whether Pim-3 regulates melanoma metastasis has not been determined. Here, we constructed a Pim-3-silencing short hairpin RNA (sh-Pim-3), a TLR7-stimulating ssRNA and a dual-function vector containing a sh-Pim-3 and a ssRNA, and transfected them into the B16F10 melanoma cell line to investigate the effects of Pim-3 on migration and invasion in melanoma. We found that sh-Pim-3 inhibited B16F10 cell migration and invasion in vitro. In a tumor-bearing mouse model, sh-Pim-3 significantly downregulated pulmonary metastasis of B16F10 melanoma cell in vivo. Mechanistically, sh-Pim-3 inhibited metastasis by regulating the expression of genes related to epithelial-mesenchymal transition (EMT). Further study revealed that by promoting the phosphorylation of STAT3 (signal transducer and activator of transcription 3), Pim-3 induced the expression of Slug, Snail, and ZEB1, which enhanced EMT-related changes and induced melanoma migration and invasion. Our study suggests that Pim-3 is a potential effective target for melanoma therapy.

Necessity of p53-binding to the CDH1 locus for its expression defines two epithelial cell types differing in their integrity

TP53 mutation (i.e., loss of normal-p53) may evoke epithelial-mesenchymal transition (EMT), which was previously attributed to loss of certain miRNAs. However, not all epithelial cells undergo EMT upon TP53 mutation, and the p53-miRNA axis may not fully explain p53 function in epithelial integrity. We here show two modes of epithelial integrity: one involves p53-binding to a nucleotide region and the other does not. In the former, p53 binds to the CDH1 (encoding E-cadherin) locus to antagonize EZH2-mediated H3K27 trimethylation (H3K27me3) to maintain high levels of acetylation of H3K27 (H3K27ac). In the latter, the same locus is not highly acetylated at H3K27, and does not allow p53-binding, nor needs to antagonize EZH2. We moreover demonstrated that although the CDH1 locus in the p53-independent cells, but not in fibroblasts, becomes high-H3K27ac by butyrate and allows p53-biniding, their CDH1 expression does not become dependent on p53. Our results identified novel modes of the epithelial integrity, in which the same epithelial-specific gene locus exhibits different requirement for p53 with different histone modifications among different epithelial cells to warrant its expression.

Fibroblast growth factor 2 induces proliferation and fibrosis via SNAI1-mediated activation of CDK2 and ZEB1 in corneal endothelium

Investigating stimulation of endogenous wound healing in corneal endothelial cells (CECs) may help address the global shortage of donor corneas by decreasing the number of transplants performed for blindness because of endothelial dysfunction. We previously reported that IL-1β stimulation leads to fibroblast growth factor (FGF2) expression, enhancing migration and proliferation of mammalian CECs. However, FGF2 also promotes the endothelial-mesenchymal transition, which can lead to retrocorneal membrane formation and blindness. This prompted us to investigate downstream FGF2 signaling targets that could be manipulated to prevent retrocorneal membrane formation. FGF2 stimulation altered cell morphology and induced expression of mesenchymal transition marker genes such as snail family transcriptional repressor 1 (SNAI1), SNAI2, zinc finger E-box-binding homeobox 1 (ZEB1), and ZEB2 This, in turn, induced expression of fibronectin, vimentin, and type I collagen, and suppressed E-cadherin in CECs in vitro and ex vivo siRNA-mediated SNAI1 knockdown revealed that SNAI1 induces ZEB1 expression, in turn inducing expression of type I collagen, the major component of retrocorneal membranes, and of cyclin-dependent kinase 2 (CDK2) and cyclin E1, promoting cell proliferation. siRNA-mediated knockdown of SNAI1 or ZEB1, but not of CDK2, inhibited FGF2-dependent expression of fibronectin, vimentin, and type I collagen and of suppression of E-cadherin expression. We conclude that SNAI1 is a key regulator of FGF2-dependent mesenchymal transition in human ex vivo corneal endothelium, with ZEB1 regulating type I collagen expression and CDK2 regulating cell proliferation. These results suggest that SNAI1 promotes fibrosis and cell proliferation in human corneal endothelium through ZEB1 and CDK2.

Nrf2 antioxidant pathway suppresses Numb-mediated epithelial-mesenchymal transition during pulmonary fibrosis

Epithelial mesenchymal transition (EMT) is a key progression that promotes pulmonary fibrosis (PF). Numb, a phosphotyrosine-binding domain (PTB) protein, is implicated with EMT. Nuclear factor erythroid 2-related factor2 (Nrf2) and its downstream proteins heme oxygenase-1 (HO-1) and NAD(P)H: quinone oxidoreductase 1 (NQO1) constitute an important pathway of antioxidant defense signal for protecting against PF. It remains elusive whether Nrf2 antioxidant pathway and Numb have a potential relationship in EMT-mediated PF. Here, we observed the effects of Nrf2 pathway and Numb on bleomycin(BLM)-induced PF in Nrf2-knockout (Nrf2-/-) and wild-type (WT) mice. Meanwhile, rat type II alveolar epithelial cells line (RLE-6TN) and human epithelial cells line (A549) were both treated with an Nrf2 activator sulforaphane (SFN), or transfected siRNAs of Nrf2 and Numb to unravel roles of Nrf2 pathway, Numb and the link between them on transforming growth factor β1 (TGF-β1)-induced EMT. We found BLM-induced lung fibrosis were more severe in Nrf2-/- mice compared to WT mice with reduced expressions of HO-1 and NQO1. Numb was enhanced with down-regulated expressions of Nrf2 in BLM groups and further increased in Nrf2-/- groups. In vitro, given exogenous TGF-β1 on RLE-6TN and A549 up-regulated Numb expressions, accompanied with down-regulations of Nrf2 and its target proteins HO-1 and NQO1. Transfected with Nrf2 and Numb siRNAs further aggravated and relieved the progression of EMT, respectively. Inversely, activating Nrf2 pathway by SFN reduced the expression of Numb and EMT-related protein. Moreover, Numb deficiency by siRNA relieved the protection of activating Nrf2 against EMT. In conclusion, activating Nrf2 antioxidant pathway suppresses EMT during PF via inhibiting the abnormal expression of Numb. These findings provide insight into PF pathogenesis and a basis for novel treatment approaches.

Ginsenoside 20(S)-Rh2 exerts anti-cancer activity through the Akt/GSK3β signaling pathway in human cervical cancer cells

Ginsenoside 20(S)-Rh2 (GRh2) is a bioactive compound derived from ginseng that is believed to maintain health in traditional Chinese medicine. Emerging evidence has suggested that GRh2 exhibits anti‑cancer activity. The present study hypothesized that GRh2 has an anti‑cancer function in human cervical cancer cells. An MTS assay demonstrated that GRh2 attenuated proliferation of HeLa cells in a dose‑ and time‑dependent manner. In addition, GRh2 inhibited migration and invasion, as determined by wound healing and transwell invasion assays, respectively. Furthermore, GRh2 treatment reduced expression of mesenchymal markers N‑cadherin and vimentin as well as epithelial mesenchymal transition transcriptional factor zinc finger E‑box‑binding homeobox 1 and snail1, and increased the protein expression levels of epithelial marker E‑cadherin. In addition, the results revealed that GRh2 prevented activation of the protein kinase B (Akt)/glycogen synthase kinase (GSK)3β signaling pathway in HeLa cells. In conclusion, the results suggested that GRh2 inhibits cervical cancer cell proliferation by targeting the Akt pathway, and prevents cervical cancer cell migration and invasion by suppressing the Akt/GSK3β regulated EMT process, and therefore, GRh2 may have the potential to be a novel anti‑cancer agent for cervical cancer.

NKILA inhibits NF-κB signaling and suppresses tumor metastasis

The long non-coding RNA (lncRNA) NKILA (nuclear transcription factor NF-κB interacting lncRNA) functions as a suppressor in human breast cancer and tongue cancer. However, the clinical significance and biological roles of NKILA in esophageal squamous cell carcinoma (ESCC) remain unknown. In this study, we showed that NKILA was downregulated in ESCC tissues and cancer cells compared with their normal counterparts. Low NKILA expression correlated with large tumor size and advanced TNM stage, and predicted poor overall and disease-free survival of ESCC patients. Further loss- and gain-of-function assays indicated that NKILA inhibited proliferation and migration of ESCC cells in vitro, suppressed tumor growth and lung metastasis in vivo. Mechanistically, NKILA could inhibit phosphorylation of IκBα, suppress p65 nuclear translocation and downregulate the expression of NF-κB target genes in ESCC cells. These results suggest NKILA could suppress malignant development of ESCC via abrogation of the NF-κB signaling and may potentially serve as a prognostic marker for ESCC.

Histone Variant MacroH2A1 Plays an Isoform-Specific Role in Suppressing Epithelial-Mesenchymal Transition

Epithelial-Mesenchymal Transition (EMT) is a biological program that plays key roles in various developmental and pathological processes. Although much work has been done on signaling pathways and transcription factors regulating EMT, the epigenetic regulation of EMT remains not well understood. Histone variants have been recognized as a key group of epigenetic regulators. Among them, macroH2A1 is involved in stem cell reprogramming and cancer progression. We postulated that macroH2A1 may play a role in EMT, a process involving reprogramming of cellular states. In this study, we demonstrate that expression of macroH2A1 is dramatically reduced during EMT induction in immortalized human mammary epithelial cells (HMLE). Moreover, ectopic expression of the macroH2A1.1 isoform, but not macroH2A1.2, can suppress EMT induction and reduce the stem-like cell population in HMLE. Interestingly, macroH2A1.1 overexpression cannot revert stable mesenchymal cells back to the epithelial state, suggesting a stage-specific role of macroH2A1.1 in EMT. We further pinpointed that the function of macroH2A1.1 in EMT suppression is dependent on its ability to bind the NAD+ metabolite PAR, in agreement with the inability to suppress EMT by macroH2A1.2, which lacks the PAR binding domain. Thus, our work discovered a previously unrecognized isoform-specific function of macroH2A1 in regulating EMT induction.

Long noncoding RNA BLACAT1 promotes cell proliferation and invasion in human cervical cancer

Cervical cancer is one of the leading causes of mortality in females worldwide. Predisposition to distant metastasis has reduced the prognosis of this malignancy, thus the identification of a novel agent for metastatic cervical cancer is required. Long noncoding RNAs (LncRNAs) have been reported to serve significant roles in human tumorigenesis. The present study aimed to investigate the effects of a newly discovered LncRNA bladder cancer associated transcript 1 (non-protein coding) (BLACAT1) on cell proliferation and metastasis in cervical cancer. A total of 100 patients with cervical cancer were included, and tumor tissues as well as the adjacent non-cancerous counterparts were collected for reverse transcription-quantitative polymerase chain reaction analysis. It was demonstrated that BLACAT1 was highly expressed in human cervical cancer tissues and cell lines. The knockdown of BLACAT1 with specific short hairpin RNA reduced colony formation rates in ME180 and C33A cells. Cell cycle and cell proliferation assays revealed that depletion of BLACAT1 in ME180, and C33A cells arrested the cell cycle at the G0/G1 phase and inhibited cell proliferation. Transwell assays demonstrated that the knockdown of BLACAT1 inhibited cell migration and invasion in ME180, and C33A cells. Moreover, wound-healing assays supported the aformentioned observations. Western blot analysis showed that the knockdown of BLACAT1 in ME180 and C33A cells decreased the protein levels of cyclin B1, cell division cycle 25C, and N-cadherin, while increasing the protein level of E-cadherin. These findings indicated the oncogenic potential of BLACAT1 in cervical cancer, which may provide novel insights for the clinical diagnosis and treatment of cervical cancer.

Nogo-B receptor promotes epithelial-mesenchymal transition in non-small cell lung cancer cells through the Ras/ERK/Snail1 pathway

Nogo-B receptor (NgBR) is a specific receptor of Nogo-B that regulates vascular remodeling and angiogenesis. Previously, we found that NgBR promotes the membrane translocation and activation of Ras in breast cancer cells and enhances the chemoresistance of hepatocellular carcinoma cells to 5-fluorouracil. However, the role of NgBR in lung cancer has not yet been elucidated. In the present study, we found that NgBR knockdown inhibited epithelial-mesenchymal transition (EMT) in non-small cell lung cancer (NSCLC) cells in vitro and metastasis of NSCLC cells in vivo. In contrast, NgBR overexpression promoted EMT in and lung metastasis of NSCLC cells. At the molecular level, NgBR modulated the expression of EMT-related proteins and enhanced the protein expression of Snail1, a crucial transcription factor that represses epithelial cell protein marker E-cadherin. Moreover, we found that NgBR overexpression promoted the membrane localization of Ras and activation of downstream MEK/ERK signaling pathway and that NgBR knockdown by using a specific shRNA inversely affected the expression of EMT-related proteins in NSCLC cells. Thus, our results provide novel insights on the regulatory role of NgBR in the metastasis of NSCLC that should be investigated further for developing a therapeutic strategy for treating patients with NSCLC.

A prototypical non-malignant epithelial model to study genome dynamics and concurrently monitor micro-RNAs and proteins in situ during oncogene-induced senescence

BACKGROUND

Senescence is a fundamental biological process implicated in various pathologies, including cancer. Regarding carcinogenesis, senescence signifies, at least in its initial phases, an anti-tumor response that needs to be circumvented for cancer to progress. Micro-RNAs, a subclass of regulatory, non-coding RNAs, participate in senescence regulation. At the subcellular level micro-RNAs, similar to proteins, have been shown to traffic between organelles influencing cellular behavior. The differential function of micro-RNAs relative to their subcellular localization and their role in senescence biology raises concurrent in situ analysis of coding and non-coding gene products in senescent cells as a necessity. However, technical challenges have rendered in situ co-detection unfeasible until now.

METHODS

In the present report we describe a methodology that bypasses these technical limitations achieving for the first time simultaneous detection of both a micro-RNA and a protein in the biological context of cellular senescence, utilizing the new commercially available SenTraGorTM compound. The method was applied in a prototypical human non-malignant epithelial model of oncogene-induced senescence that we generated for the purposes of the study. For the characterization of this novel system, we applied a wide range of cellular and molecular techniques, as well as high-throughput analysis of the transcriptome and micro-RNAs.

RESULTS

This experimental setting has three advantages that are presented and discussed: i) it covers a "gap" in the molecular carcinogenesis field, as almost all corresponding in vitro models are fibroblast-based, even though the majority of neoplasms have epithelial origin, ii) it recapitulates the precancerous and cancerous phases of epithelial tumorigenesis within a short time frame under the light of natural selection and iii) it uses as an oncogenic signal, the replication licensing factor CDC6, implicated in both DNA replication and transcription when over-expressed, a characteristic that can be exploited to monitor RNA dynamics.

CONCLUSIONS

Consequently, we demonstrate that our model is optimal for studying the molecular basis of epithelial carcinogenesis shedding light on the tumor-initiating events. The latter may reveal novel molecular targets with clinical benefit. Besides, since this method can be incorporated in a wide range of low, medium or high-throughput image-based approaches, we expect it to be broadly applicable.

Deubiquitinating enzyme PSMD14 promotes tumor metastasis through stabilizing SNAIL in human esophageal squamous cell carcinoma

The epithelial-mesenchymal transition (EMT) transcription factor SNAIL is associated with distant metastasis and poor prognosis of esophageal squamous cell carcinoma (ESCC) patients. The proteolysis of SNAIL is mediated by the ubiquitin-proteasome system. Several E3 ligases have been characterized to promote SNAIL ubiquitination and degradation. However, the reverse process - deubiquitination of SNAIL remains largely unknown. In this study, we performed a mass spectrometry to examine the interaction between SNAIL and deubiquitinating enzyme(s). Subsequently, the deubiquitinating enzyme PSMD14 was identified to target SNAIL for deubiquitination and stabilization. Furthermore, knockdown of PSMD14 significantly blocks SNAIL-induced EMT and then suppresses tumor cell migration and invasion in vitro and tumor metastasis in vivo. In addition, the high expression level of PSMD14 predicts poor prognosis for esophageal cancer patients. These findings suggest PSMD14 as a bona fide deubiquitinating enzyme to regulate SNAIL at the post-translational level and provide a promising therapeutic strategy against tumor metastasis of esophageal cancer.

Glucose-6-phosphate dehydrogenase is indispensable in embryonic development by modulation of epithelial-mesenchymal transition via the NOX/Smad3/miR-200b axis

Glucose-6-phosphate dehydrogenase (G6PD) is a housekeeping enzyme involved in the pentose phosphate shunt for producing nicotinamide adenine dinucleotide phosphate (NADPH). Severe G6PD deficiency leads to embryonic lethality, but the underlying mechanism is unclear. In the current study, the effects of G6PD on epithelial-mesenchymal transition (EMT), especially during embryonic development, were investigated. The knockdown of G6PD induced morphological changes, accompanied by the suppression of epithelial markers, E-cadherin and β-catenin, in A549 and MDCK cells. Such modulation of EMT was corroborated by the enhancement of migration ability in G6PD-knockdown A549 cells. Zebrafish embryos with g6pd knockdown exhibited downregulation of the E-cadherin/β-catenin adhesion molecules and impaired embryonic development through reduction in epiboly rate and increase in cell shedding at the embryo surface. The dysregulation in zebrafish embryonic development caused by g6pd knockdown could be rescued through human G6PD or CDH1 (E-cadherin gene) cRNA coinjection. The Smad3/miR-200b axis was dysregulated upon G6PD knockdown, and the reconstitution of SMAD3 in G6PD-knockdown A549 cells restored the expression of E-cadherin/β-catenin. The inhibition of NADPH oxidase (NOX) activation through the loss of p22_phox signaling was involved in the dysregulation of the Smad3/miR-200b axis upon G6PD knockdown. The reconstitution of G6PD led to the recovery of the regulation of NOX/Smad3/miR-200b signaling and increased the expression of E-cadherin/β-catenin in G6PD-knockdown cells. Thus, these results suggest that in the EMT process, G6PD plays an important regulatory role as an integral component of the NOX/Smad3/miR-200b axis.

Epigenetic plasticity and the hallmarks of cancer

Chromatin and associated epigenetic mechanisms stabilize gene expression and cellular states while also facilitating appropriate responses to developmental or environmental cues. Genetic, environmental, or metabolic insults can induce overly restrictive or overly permissive epigenetic landscapes that contribute to pathogenesis of cancer and other diseases. Restrictive chromatin states may prevent appropriate induction of tumor suppressor programs or block differentiation. By contrast, permissive or "plastic" states may allow stochastic oncogene activation or nonphysiologic cell fate transitions. Whereas many stochastic events will be inconsequential "passengers," some will confer a fitness advantage to a cell and be selected as "drivers." We review the broad roles played by epigenetic aberrations in tumor initiation and evolution and their potential to give rise to all classic hallmarks of cancer.

Integration of pan-cancer transcriptomics with RPPA proteomics reveals mechanisms of epithelial-mesenchymal transition

Integrating data from multiple regulatory layers across cancer types could elucidate additional mechanisms of oncogenesis. Using antibody-based protein profiling of 736 cancer cell lines, along with matching transcriptomic data, we show that pan-cancer bimodality in the amounts of mRNA, protein, and protein phosphorylation reveals mechanisms related to the epithelial-mesenchymal transition (EMT). Based on the bimodal expression of E-cadherin, we define an EMT signature consisting of 239 genes, many of which were not previously associated with EMT. By querying gene expression signatures collected from cancer cell lines after small-molecule perturbations, we identify enrichment for histone deacetylase (HDAC) inhibitors as inducers of EMT, and kinase inhibitors as mesenchymal-to-epithelial transition (MET) promoters. Causal modeling of protein-based signaling identifies putative drivers of EMT. In conclusion, integrative analysis of pan-cancer proteomic and transcriptomic data reveals key regulatory mechanisms of oncogenic transformation.

Profiling molecular and phenotypic characteristics of large collections of cancer cell lines can be used to identify distinct and common oncogenic pathways across cancer types. So far, most large-scale data obtained from cancer cell lines have been at the genomic, transcriptomic, and phenotypic levels. Recently, high-quality data at the level of cell signaling through protein abundances and phosphorylation sites has become available. By integrating this newly generated protein data with prior transcriptomic data, and by visualizing all cancer cell lines using dimensionality reduction techniques, pan-cancer cell lines are strikingly shown to organize into a gradient of epithelial to mesenchymal types. Interestingly, many of the measured proteins and transcripts display bimodality; the expression of genes, proteins, and protein phosphorylations is either high or low, strongly suggesting that they act as molecular switches. Focusing on further characterizing molecular switches of epithelial-mesenchymal transitions, we identify candidate regulators and small molecules that can induce or reverse such transition, as well as potential causal relationships between proteins. Since the mesenchymal state of tumors is known to be associated with metastasis and later-stage cancer development, better understanding the regulatory mechanisms of epithelial-to-mesenchymal transition can lead to improved targeted therapeutics.

FOXO1/3: Potential suppressors of fibrosis

Fibrosis is a universally age-related disease that involves nearly all organs. It is typically initiated by organic injury and eventually results in organ failure. There are still few effective therapeutic strategy targets for fibrogenesis. Forkhead box proteins O1 and O3 (FOXO1/3) have been shown to have favorable inhibitory effects on fibroblast activation and subsequent extracellular matrix production and can ameliorate fibrosis levels in numerous organs, including the heart, liver, lung, and kidney; they are therefore promising targets for anti-fibrosis therapy. Moreover, we can develop appropriate strategies to make the best use of FOXO1/3's anti-fibrosis properties. The information reviewed here should be significant for understanding the roles of FOXO1/3 in fibrosis and should contribute to the design of further studies related to FOXO1/3 and the fibrotic response and shed light on a potential treatment for fibrosis.

Overexpression of MICAL2, a novel tumor-promoting factor, accelerates tumor progression through regulating cell proliferation and EMT

Molecule interacting with CasL 2 (MICAL2), a microtubule associated monooxygenase, is involved in cell growth, axon guidance, vesicle trafficking and apoptosis. Recent studies have demonstrated that MICAL2 is highly expressed in tumor and accelerates tumor progression and it is deemed to be a novel tumor-promoting factor. MICAL2 overexpression increases cell proliferation to accelerate tumor growth, and MICAL2 also promotes epithelial-mesenchymal transition (EMT)-related proteins to increase cancer cell metastasis. On mechanism, MICAL2 induces EMT by regulating SRF (serum response factor)/MRTF-A (myocardin related transcription factor A) signaling, Semaphorin/Plexin pathway and inducing ROS (Reactive oxygen species) production. In the present review, we introduced MICAL family, expatiated the structure and functions of MICALs, and summarized the mechanisms of MICAL2 involving tumor progression. The challenges and perspectives for MICAL2 in tumor are also discussed.

Smad3-STAT3 crosstalk in pathophysiological contexts

Smad3 and STAT3 are intracellular molecules that transmit signals from plasma membrane receptors to the nucleus. Smad3 operates downstream of growth/differentiation factors that utilize activin receptor-like kinase (ALK)-4, 5, or 7, such as transforming growth factor-β (TGF-β), activin, and myostatin. STAT3 principally functions downstream of cytokines that exert their effects via gp130 and Janus family kinases, including interleukin-6 (IL-6), leukemia inhibitory factor (LIF), and oncostatin M. Accumulating evidence indicates that Smad3 and STAT3 engage in crosstalk in a highly context-dependent fashion, cooperating in some conditions while acting antagonistically each other in others. Here, we review the crosstalk between Smad3 and STAT3 in various biological contexts, including early tumorigenesis, epithelial-mesenchymal transition, fibrosis, and T cell differentiation.

An In Vitro System to Study the Epithelial-Mesenchymal Transition In Vitro

The epithelial-mesenchymal transition (EMT) plays an important role in development and cancer progression. Upon EMT, epithelial cells lose stable cell-cell adhesions and reorganize their cytoskeleton to acquire migratory activity. Recent data demonstrated that EMT drives cancer cells from the epithelial state to a hybrid epithelial/mesenchymal phenotype with retention of some epithelial markers (in particular, E-cadherin), which is important for cancer cell dissemination. In vitro studies of the effect of growth factors (in particular, epidermal growth factor (EGF)) on cultured cells can be highly advantageous for understanding the details of the early stages of EMT. The methods described in this chapter are intended for studying intermediate phenotypes of EMT. Time-lapse DIC microscopy is used for visualization of changes in morphology and motility of the cells stimulated with EGF. The transwell migration assay allows the evaluation of the migratory activity of the cells. Studying of dynamics of a fluorescently labeled actin-binding protein F-tractin-tdTomato using confocal microscopy allows detection of EGF-induced changes in the organization of the actin cytoskeleton. Live-cell imaging of cells stably expressing GFP-E-cadherin visualizes reorganization of stable tangential E-cadherin-based adherens junctions (AJs) into unstable radial AJs during the early stages of EMT.

Developmental effects of the protein kinase inhibitor kenpaullone on the sea urchin embryo

The selection and validation of bioactive compounds require multiple approaches, including in-depth analyses of their biological activity in a whole-animal context. We exploited the sea urchin embryo in a rapid, medium-scale range screening to test the effects of the small synthetic kinase inhibitor kenpaullone. We show that sea urchin embryos specifically respond to this molecule depending on both dose and timing of administration. Phenotypic effects of kenpaullone are not immediately visible, since this molecule affects neither the fertilization nor the spatial arrangement of blastomeres at early developmental stages. Nevertheless, kenpaullone exposure from the beginning of embryogenesis profoundly perturbs specification, detachment from the epithelium, and migration of the primary mesenchyme cells, thus affecting the whole embryonic epithelial mesenchymal transition process. Our results reaffirm the sea urchin embryo as an excellent and sensitive in vivo system, which provides straightforward and rapid response to external stimuli.

Expression of proteins associated with epithelial-mesenchymal transition in esophageal squamous cell carcinoma

Cluster of differentiation 147 (CD147), pituitary tumor transforming gene (PTTG) and CD44v6 are proteins involved in the epithelial-mesenchymal transition (EMT). To investigate the prognostic value of CD147 and PTTG, and CD44v6 expression in esophageal squamous cell carcinoma (ESCC), tissue microarray specimens from 76 patients with ESCC were evaluated by immunohistochemistry staining and scored by intensity and proportion of positive areas. Expression levels of CD147, PTTG and CD44v6 were higher in tumor tissues than in matched adjacent tissues. CD147 expression was positively associated with lymph node metastasis (P=0.025) and American Joint Committee on Cancer (AJCC) system clinical grades (P=0.037). CD147 expression was positively correlated with the expression levels of PTTG (R=0.369; P=0.001) and CD44v6 (R=0.320; P=0.005). In addition, Kaplan-Meier analysis indicated that positive expression of CD147, PTTG and CD44v6 was significantly associated with poor overall survival times (P=0.045, P=0.014 and P=0.027, respectively). Patients exhibiting CD147-PTTG co-expression, CD147-CD44v6 co-expression and CD147-PTTG-CD44v6 triple-positive expression had the poorest overall survival rates. In conclusion, the expression of EMT-associated proteins, including CD147, PTTG and CD44v6, was significantly associated with poor survival in ESCC and these novel targets may serve as potential biomarkers for anticancer therapies.

Hypoxia-inducible factor-1α regulates epithelial-to-mesenchymal transition in paraquat-induced pulmonary fibrosis by activating lysyl oxidase

Pulmonary fibrosis (PF) is one of the most prevalent causes of death following paraquat (PQ) poisoning. As demonstrated in previous studies by the present authors, epithelial-to-mesenchymal transition (EMT) is associated with PQ-induced PF. In addition, hypoxia-inducible factor-1α (HIF-1α) and lysyl oxidase (LOX) promote EMT following PQ poisoning. However, the association between HIF-1α- and LOX-mediated regulation of EMT remains unclear. The present study investigated the association between HIF-1α and LOX with regard to PQ-induced EMT. A549 and RLE-6TN cells were treated with PQ, and HIF-1α and LOX expression was silenced with short interfering RNAs. Changes in the expression of HIF-1α, LOX, β-catenin and EMT-related makers were detected using real-time quantitative polymerase chain reaction, immunofluorescence, and western blotting. HIF-1α and LOX were associated with PQ-induced EMT, and their expression levels were significantly increased (P<0.05). LOX expression was significantly decreased following PQ poisoning when HIF-1α expression was inhibited (P<0.05). However, the level of HIF-1α did not change significantly when LOX was silenced. The expression level of β-catenin and the degree of EMT were significantly decreased following HIF-1α and LOX silencing in both cell lines (P<0.05). The association between HIF-1α and LOX in regulating EMT during PQ-induced PF may be unidirectional. HIF-1α may regulate PQ-induced EMT through the LOX/β-catenin pathway.

Circulating Tumor Cells and Implications of the Epithelial-to-Mesenchymal Transition

The majority of cancer-related deaths result from metastasis, the process by which cancer cells escape the primary tumor site and enter into the blood circulation in order to disseminate to secondary locations throughout the body. Tumor cells found within the circulation are referred to as circulating tumor cells (CTCs), and their detection and enumeration correlate with poor prognosis. The epithelial-to-mesenchymal transition (EMT) is a dynamic process that imparts epithelial cells with mesenchymal-like properties, thus facilitating tumor cell dissemination and contributing to metastasis. However, EMT also results in the downregulation of various epithelial proteins typically utilized by CTC technologies for enrichment and detection of these rare cells, resulting in reduced detection of some CTCs, potentially those with a more metastatic phenotype. In addition to the current clinical role of CTCs as a prognostic biomarker, they also have potential as a predictive biomarker via CTC characterization. However, CTC characterization is complicated by the unknown biological significance of CTCs possessing an EMT-like phenotype, and the ability to capture and understand this CTC subpopulation is an essential step in the utilization of CTCs for patient management. This chapter will review the process of EMT and its contribution to metastasis; discusses current and future clinical applications of CTCs; and describes both traditional and novel methods for CTC enrichment, detection, and characterization with a specific focus on CTCs with an EMT phenotype.

Unfolded Protein Response of the Endoplasmic Reticulum in Tumor Progression and Immunogenicity

The endoplasmic reticulum (ER) is a pivotal regulator of folding, quality control, trafficking, and targeting of secreted and transmembrane proteins, and accordingly, eukaryotic cells have evolved specialized machinery to ensure that the ER enables these proteins to acquire adequate folding and maturation in the presence of intrinsic and extrinsic insults. This adaptive capacity of the ER to intrinsic and extrinsic perturbations is important for maintaining protein homeostasis, which is termed proteostasis. Failure in adaptation to these perturbations leads to accumulation of misfolded or unassembled proteins in the ER, which is termed ER stress, resulting in the activation of unfolded protein response (UPR) of the ER and the execution of ER-associated degradation (ERAD) to restore homeostasis. Furthermore, both of the two axes play key roles in the control of tumor progression, inflammation, immunity, and aging. Therefore, understanding UPR of the ER and subsequent ERAD will provide new insights into the pathogenesis of many human diseases and contribute to therapeutic intervention in these diseases.

Pleiotropic Roles for ZEB1 in Cancer

ZEB1 is a prime element of a network of transcription factors that controls epithelial-to-mesenchymal transition (EMT), a reversible embryonic transdifferentiation program that allows partial or complete transition from an epithelial to a mesenchymal state. Aberrant expression of ZEB1 has been reported in a variety of human cancers, where it is generally believed to foster migration, invasion, and metastasis. Over the past few years, in vitro and in vivo observations have highlighted unsuspected intrinsic oncogenic functions of ZEB1 that impact tumorigenesis from its earliest stages. Located downstream of regulatory processes that integrate microenvironmental signals and directly implicated in feedback loops controlled by miRNAs, ZEB1 appears to be a central switch that determines cell fate. Its expression fosters malignant transformation through the mitigation of critical oncosuppressive pathways and through the conferment of stemness properties. ZEB1 is also a key determinant of cell plasticity, endowing cells with the capacity to withstand an aberrant mitogenic activity, with a profound impact on the genetic history of tumorigenesis, and to adapt to the multiple constraints encountered over the course of tumor development. Cancer Res; 78(1); 30-35. ©2017 AACR.

Celecoxib targets breast cancer stem cells by inhibiting the synthesis of prostaglandin E2 and down-regulating the Wnt pathway activity

Pharmacological targeting of breast cancer stem cells (CSCs) is highly promising for the treatment of breast cancer, as the small population of CSCs is responsible for tumor initiation, progression, recurrence and chemo-resistance. Celecoxib is one of the most commonly used non-steroidal anti-inflammatory drugs (NSAIDs), which have chemo-preventive activity against cancers, including breast cancer and colorectal cancer. However, the mechanisms by which NSAIDs exert its cancer prevention effects have yet been completely understood. In the present study, we investigated for the first time the effect of celecoxib on breast CSCs inhibition and its potential molecular mechanisms. Our results demonstrated that celecoxib suppresses CSC self-renewal, sensitizes chemo-resistance, inhibits epithelial to mesenchymal transition (EMT), and attenuates metastasis and tumorigenesis. Further exploring the underlying mechanism revealed that celecoxib targets breast CSCs by inhibiting the synthesis of prostaglandin E₂ and down-regulating the Wnt pathway activity. Our findings suggest that celecoxib, by targeting CSCs, may be used as an adjuvant chemotherapy drug to improve breast cancer treatment outcomes.

Epithelial-Mesenchymal Transition in Pancreatic Cancer: A Review

Pancreatic ductal adenocarcinoma (PDAC) is one of the most aggressive solid malignancies and is characterized by its insensitivity to current therapy. The invasion and metastasis of solid tumors such as PDAC are complex processes involving many factors. Recent insights into the role of cancer stem cells (CSCs) and the epithelial-mesenchymal transition (EMT) in tumorigenesis have increased the knowledge base and highlighted new therapeutic targets of this disease. The process of EMT is regulated by a complex network of cytokines, transcription factors, growth factors, signaling pathways, and the tumor microenvironment, exhibiting CSC-like properties. The transition of solid cancer cells from an epithelial to a mesenchymal phenotype increases their migratory and invasive properties, thus promoting metastasis. In PDAC, the exact influence of EMT on the biological behaviors of cancer cells and its impact on clinical therapy remain controversial, but the therapeutic strategy of combining EMT inhibition with chemotherapy deserves attention. Alternatively, anti-inflammatory therapy that targets the interaction between inflammation and EMT is a valid strategy for treating the premalignant stage of tumor progression. In this review, we summarize the latest research on EMT and the potential relationship between EMT and PDAC.

Molecular Genetic Analysis of Human Endometrial Mesenchymal Stem Cells That Survived Sublethal Heat Shock

High temperature is a critical environmental and personal factor. Although heat shock is a well-studied biological phenomenon, hyperthermia response of stem cells is poorly understood. Previously, we demonstrated that sublethal heat shock induced premature senescence in human endometrial mesenchymal stem cells (eMSC). This study aimed to investigate the fate of eMSC-survived sublethal heat shock (SHS) with special emphasis on their genetic stability and possible malignant transformation using methods of classic and molecular karyotyping, next-generation sequencing, and transcriptome functional analysis. G-banding revealed random chromosome breakages and aneuploidy in the SHS-treated eMSC. Molecular karyotyping found no genomic imbalance in these cells. Gene module and protein interaction network analysis of mRNA sequencing data showed that compared to untreated cells, SHS-survived progeny revealed some difference in gene expression. However, no hallmarks of cancer were found. Our data identified downregulation of oncogenic signaling, upregulation of tumor-suppressing and prosenescence signaling, induction of mismatch, and excision DNA repair. The common feature of heated eMSC is the silence of MYC, AKT1/PKB oncogenes, and hTERT telomerase. Overall, our data indicate that despite genetic instability, SHS-survived eMSC do not undergo transformation. After long-term cultivation, these cells like their unheated counterparts enter replicative senescence and die.

MicroRNA-93 promotes proliferation and metastasis of gastric cancer via targeting TIMP2

MicroRNAs (miRNAs) are important regulators of pathobiological processes in various cancer. In the present study, we demonstrated that miR-93 expression was significantly up-regulated in gastric cancer tissues compared with that in matched normal mucosal tissues. High expression of miR-93 was significantly associated with lymph node metastasis and tumor-node-metastasis (TNM) stage. Functionally, ectopic expression of miR-93 promoted cell proliferation, migration, invasion, EMT phenotypes, and repressed apoptosis and G1 cell cycle arrest in vitro, and promoted tumor formation in vivo. We further identified that tissue inhibitor of metalloproteinase 2 (TIMP2) was a direct target of miR-93 by using luciferase reporter assay, qRT-PCR, and immunoblotting assay. Furthermore, knockdown of TIMP2 with specific siRNA showed similar oncogenic effects in gastric cancer cells with that transfected with miR-93 mimics. Our findings indicated that miR-93 serves as a tumor promoter in human gastric carcinogenesis by targeting TIMP2, suggesting that miR-93 might be a promising biomarker and therapeutic target for treatment of gastric cancer.

Carcinosarcomas and Related Cancers: Tumors Caught in the Act of Epithelial-Mesenchymal Transition

In this review, we outline the biology and management of patients with carcinosarcomas and related malignancies, which are often included under the broader concept of sarcomatoid carcinomas. Carcinosarcomas are unusual tumors that are commonly gynecologic in origin, where they are referred to as malignant mixed Müllerian tumors, but may appear in any anatomic site. Although a variety of hypotheses have been presented as to the biphasic nature of these tumors, carcinosarcomas seem to represent the best example in human cancers of the concept of epithelial-mesenchymal transition (EMT), in which the two parts of the tumor are genomically related to one another, as opposed to the mesenchymal component that represents a second neoplasm or (benign) reactive process. In general, patients with carcinosarcomas fare worse than patients with carcinomas of the same anatomic site. Treatment paradigms for carcinosarcomas generally follow those of carcinomas of the same organ site, except where clinical trials provide more specific options. Agents that block or reverse EMT are worth examination in patients with carcinosarcoma and arguably may be even more effective in carcinomas, given evidence of dependence on EMT to generate successful metastases. Information about EMT may also inform other phase transitions in cancer, such as those between prostate or lung carcinoma and more aggressive tumors with neuroendocrine differentiation.

Comparative gene co-expression network analysis of epithelial to mesenchymal transition reveals lung cancer progression stages

BACKGROUND

The epithelial to mesenchymal transition (EMT) plays a key role in lung cancer progression and drug resistance. The dynamics and stability of gene expression patterns as cancer cells transition from E to M at a systems level and relevance to patient outcomes are unknown.

METHODS

Using comparative network and clustering analysis, we systematically analyzed time-series gene expression data from lung cancer cell lines H358 and A549 that were induced to undergo EMT. We also predicted the putative regulatory networks controlling EMT expression dynamics, especially for the EMT-dynamic genes and related these patterns to patient outcomes using data from TCGA. Example EMT hub regulatory genes were validated using RNAi.

RESULTS

We identified several novel genes distinct from the static states of E or M that exhibited temporal expression patterns or 'periods' during the EMT process that were shared in different lung cancer cell lines. For example, cell cycle and metabolic genes were found to be similarly down-regulated where immune-associated genes were up-regulated after middle EMT stages. The presence of EMT-dynamic gene expression patterns supports the presence of differential activation and repression timings at the transcriptional level for various pathways and functions during EMT that are not detected in pure E or M cells. Importantly, the cell line identified EMT-dynamic genes were found to be present in lung cancer patient tissues and associated with patient outcomes.

CONCLUSIONS

Our study suggests that in vitro identified EMT-dynamic genes capture elements of gene EMT expression dynamics at the patient level. Measurement of EMT dynamic genes, as opposed to E or M only, is potentially useful in future efforts aimed at classifying patient's responses to treatments based on the EMT dynamics in the tissue.

I131 reinforces antitumor activity of metuximab by reversing epithelial-mesenchymal transition via VEGFR-2 signaling in hepatocellular carcinoma

CD147 is highly expressed in hepatocellular carcinoma (HCC) and associated with the invasion and metastasis of HCC. The efficacy of I¹³¹ -metuximab (I¹³¹ -mab), a newly developed agent that targets CD147, as a radio-immunotherapy for local HCC, has been validated in clinical practice. However, the synergistic anticancer activity and molecular mechanism of different conjugated components within I¹³¹ -mab remain unclear. In this study, the cytological experiments proved that I¹³¹ -mab inhibited the proliferation and invasion of HCC cells. Mechanically, this inhibition effect was mainly mediated by the antibody component part of I¹³¹ -mab, which could reverse the epithelial-mesenchymal transition of HCC cells partially by suppressing the phosphorylation of VEGFR-2. The inhibitory effect of I¹³¹ on HCC cell proliferation and invasion is limited, whereas, when combined with metuximab, I¹³¹ significantly enhanced the sensitivity of HCC cells to CD147-mab and consequently reinforced the anticancer effects of CD147-mab, suggesting that the two components of I¹³¹ -mab exerted synergistic anti-HCC capability. Furthermore, the experiments using SMMC-7721 human HCC xenografts in athymic nude mice showed that I¹³¹ -mab and CD147-mab significantly inhibited the growth of xenograft tumors and that I¹³¹ -mab was more effective than CD147-mab. In conclusion, our results elucidated the mechanism underlying the anti-HCC effects of I¹³¹ -mab and provided a theoretical foundation for the clinical application of I¹³¹ -mab.

Symmetry and symmetry breaking in cancer: a foundational approach to the cancer problem

Symmetry and symmetry breaking concepts from physics and biology are applied to the problem of cancer. Three categories of symmetry breaking in cancer are examined: combinatorial, geometric, and functional. Within these categories, symmetry breaking is examined for relevant cancer features, including epithelial-mesenchymal transition (EMT); tumor heterogeneity; tensegrity; fractal geometric and information structure; functional interaction networks; and network stabilizability and attack tolerance. The new cancer symmetry concepts are relevant to homeostasis loss in cancer and to its origin, spread, treatment and resistance. Symmetry and symmetry breaking could provide a new way of thinking and a pathway to a solution of the cancer problem.

Factors involved in cancer metastasis: a better understanding to "seed and soil" hypothesis

Metastasis has intrigued researchers for more than 100 years. Despite the development of technologies and therapeutic strategies, metastasis is still the major cause of cancer-related death until today. The famous "seed and soil" hypothesis is widely cited and accepted, and it still provides significant instructions in cancer research until today. To our knowledge, there are few reviews that comprehensively and correlatively focus on both the seed and soil factors involved in cancer metastasis; moreover, despite the fact that increasingly underlying mechanisms and concepts have been defined recently, previous perspectives are appealing but may be limited. Hence, we reviewed factors involved in cancer metastasis, including both seed and soil factors. By integrating new concepts with the classic hypothesis, we aim to provide a comprehensive understanding of the "seed and soil" hypothesis and to conceptualize the framework for understanding factors involved in cancer metastasis. Based on a dynamic overview of this field, we also discuss potential implications for future research and clinical therapeutic strategies.

Sirtuins at the crossroads of stemness, aging, and cancer

Sirtuins are stress‐responsive proteins that direct various post‐translational modifications (PTMs) and as a result, are considered to be master regulators of several cellular processes. They are known to both extend lifespan and regulate spontaneous tumor development. As both aging and cancer are associated with altered stem cell function, the possibility that the involvement of sirtuins in these events is mediated by their roles in stem cells is worthy of investigation. Research to date suggests that the individual sirtuin family members can differentially regulate embryonic, hematopoietic as well as other adult stem cells in a tissue‐ and cell type‐specific context. Sirtuin‐driven regulation of both cell differentiation and signaling pathways previously involved in stem cell maintenance has been described where downstream effectors involved determine the biological outcome. Similarly, diverse roles have been reported in cancer stem cells (CSCs), depending on the tissue of origin. This review highlights the current knowledge which places sirtuins at the intersection of stem cells, aging, and cancer. By outlining the plethora of stem cell‐related roles for individual sirtuins in various contexts, our purpose was to provide an indication of their significance in relation to cancer and aging, as well as to generate a clearer picture of their therapeutic potential. Finally, we propose future directions which will contribute to the better understanding of sirtuins, thereby further unraveling the full repertoire of sirtuin functions in both normal stem cells and CSCs.

Sinomenine hydrochloride attenuates the proliferation, migration, invasiveness, angiogenesis and epithelial-mesenchymal transition of clear-cell renal cell carcinoma cells via targeting Smad in vitro

New strategies for the treatment of clear-cell renal cell carcinoma (ccRCC) are urgently needed. Recently, accumulating evidence has demonstrated that sinomenine hydrochloride (SH), extracted from the plant sinomenium acutum, has potent anti-cancer activity in multiple human malignant solid tumors. However, the underlying molecular mechanism by which SH treatment exerts its antagonizing tumorigenic effects has not been clearly elucidated. In this study, we showed that SH treatment exerted profound effects on cell growth in ccRCC in a dose- and time-dependent manner in vitro. Furthermore, treatment with SH significantly suppressed the migration, invasiveness and angiogenesis of ccRCC cells in vitro. Mechanistically, we revealed that SH treatment blocked epithelial-mesenchymal transition (EMT) through the downregulation of the expression of the transcription factors Snail1 and Twist in ccRCC cells. Additionally, the depletion of p-Smad2 and p-Smad3 was required for SH treatment to inhibit EMT effectively. Taken together, these findings indicate an anti-cancer role for SH in ccRCC cells and reveal a potential molecular mechanism by which Smad / EMT axis functions in ccRCC, as its hyperactivation has been associated with cell proliferation, migration, invasiveness and angiogenesis in this cancer type. These observations suggest that SH can act as an efficacious adjuvant chemotherapeutic candidate that targets the Smad/EMT axis in patients with ccRCC.

Neural crest and cancer: Divergent travelers on similar paths

Neural crest cells are multipotent progenitors that dynamically interpret diverse microenvironments to migrate significant distances as a loosely associated collective and contribute to many tissues in the developing vertebrate embryo. Uncovering details of neural crest migration has helped to inform a general understanding of collective cell migration, including that which occurs during cancer metastasis. Here, we discuss several commonalities and differences of neural crest and cancer cell migration and behavior. First, we focus on some of the molecular pathways required for the initial specification and potency of neural crest cells and the roles of many of these pathways in cancer progression. We also describe epithelial-to-mesenchymal transition, which plays a critical role in initiating both neural crest migration and cancer metastasis. Finally, we evaluate studies that demonstrate myriad forms of cell-cell and cell-environment communication during neural crest and cancer collective migration to highlight the remarkable similarities in their molecular and cell biological regulation.

Mechanisms that drive inflammatory tumor microenvironment, tumor heterogeneity, and metastatic progression

Treatment of cancer metastasis has been largely ineffective. It is paramount to understand the mechanisms underlying the metastatic process, of which the tumor microenvironment is an indispensable participant. What are the critical cellular and molecular players at the primary tumor site where metastatic cascade initiates? How is tumor-associated inflammation regulated? How do altered vasculatures contribute to metastasis? What is the dynamic nature or heterogeneity of primary tumors and what are the challenges to catch a moving target? This review summarizes recent progress, mechanistic understanding, and options for metastasis-targeted therapy.

Long non-coding RNA lncTCF7 activates the Wnt/β-catenin pathway to promote metastasis and invasion in colorectal cancer

Long non-coding RNA (Lnc)TCF7 is a novel lncRNA that is involved in tumorigenesis. Previous studies have revealed that lncTCF7 serves an essential role in maintaining cancer stem cell self-renewal; however, the functions of lncTCF7 in colorectal cancer (CRC) remain unknown. Therefore, the present study aimed to investigate the role of lncTCF7 in CRC. LncTCF7 was upregulated in 52/58 CRC tissues, and its expression correlated with tumor size, lymph metastasis and tumor-node-metastasis stage in CRC. Knocking down lncTCF7 in colon cancer cell lines decreased cell proliferation, migration and invasion, while lncTCF7 overexpression showed opposite changes. In addition, lncTCF7 promoted cell proliferation in vivo. LncTCF7 activated the Wnt/β-catenin signaling pathway, which is essential for cancer development. Survival analysis revealed that patients with higher expression of lncTCF7 had significantly worse prognosis compared with patients with low expression. These findings indicate that lncTCF7 regulates CRC progression and support the notion of lncTCF7 as a CRC prognostic marker.

Epithelial-mesenchymal transition and inflammation at the site of the primary tumor

Tumor growth and progression are the products of complex signaling networks between different cell types within the tumor and its surrounding stroma. In particular, established tumors are known to stimulate an inflammatory reaction via the secretion of cytokines, chemokines, and growth factors that favor the recruitment of a range of infiltrating immune cell populations into the tumor microenvironment. While potentially able to exert tumor control, this inflammatory reaction is typically seized upon by the tumor to promote its own growth and progression towards metastasis. This review focuses on recent advances in understanding how an established tumor can initiate an inflammatory response via the release of pro-inflammatory mediators, such as IL-6 and IL-8, and their roles in cancer metastasis. In particular, the role of the epithelial-mesenchymal transition (EMT), a phenotypic switch observed in carcinomas that promotes progression towards metastasis, is discussed here in relation to cancer inflammation.

miR-200b-containing microvesicles attenuate experimental colitis associated intestinal fibrosis by inhibiting epithelial-mesenchymal transition

BACKGROUND AND AIM

Epithelial-mesenchymal transition (EMT), characterized by the decrease of E-cadherin (E-Cad) and increase in vimentin and alpha-smooth muscle actin (α-SMA), was demonstrated to participate in inflammatory bowel disease-related fibrosis. miR-200b plays an anti-fibrosis role in inhibiting EMT by targeting ZEB1 and ZEB2. But the stability of exogenous miR-200b in blood limits its application. Microvesicles (MVs), which can transfer miRNAs among cells and prevent them from degradation, may provide an excellent transport system for the delivery of miR-200b in the treatment of fibrosis.

METHODS

Bone marrow mesenchymal stem cells (BMSCs) were transfected with lentivirus to overexpress miR-200b. The MVs packaged with miRNA-200b were harvested for the anti-fibrotic treatment using in vitro (transforming growth factor beta 1-mediated EMT in intestinal epithelial cells: IEC-6) and in vivo (TNBS-induced intestinal fibrosis in rats) models. The pathological morphology was observed, and the fibrosis related proteins, such as E-Cad, vimentin, α-SMA, ZEB1, and ZEB2, were detected.

RESULTS

MiR-200b-MVs would significantly reverse the morphology in TGF-β1-treated IEC-6 cells and improve the TNBS-induced colon fibrosis histologically. The treatment of miR-200b-MVs increased miR-200b levels both in the IEC-6 cells and colon, resulting in a significant prevention EMT and alleviation of fibrosis. The expression of E-Cad was increased, and the expressions of vimentin and α-SMA were decreased. ZBE1 and ZEB2, the targets of miR-200b, were also decreased.

CONCLUSIONS

miR-200b could be transferred from genetically modified BMSCs to the target cells or tissue by MVs. The mechanisms of miR-200b-MVs in inhibiting colonic fibrosis were related to suppressing the development of EMT by targeting ZEB1and ZEB2.

Modulation of the TGF-β1-induced epithelial to mesenchymal transition (EMT) mediated by P1 and P2 purine receptors in MDCK cells

Epithelial to mesenchymal transition (EMT) occurs during embryogenesis or under pathological conditions such as hypoxia, injury, chronic inflammation, or tissue fibrosis. In renal tubular epithelial cells (MDCK), TGF-β1 induces EMT by reducing or increasing epithelial or mesenchymal marker expression, respectively. In this study, we confirmed that the cAMP analogues, 8-CPT-cAMP or N6-Ph-cAMP, inhibited the TGF-β1-driven overexpression of the mesenchymal markers ZEB-1, Slug, Fibronectin, and α-SMA. Furthermore, we showed that A1, A2A, P2Y1, P2Y11, and P2X7 purine receptor agonists modulated the TGF-β1-induced EMT through the involvement of PKA and/or MAPK/ERK signaling. The stimulation of A2A receptor reduced the overexpression of the EMT-related markers, mainly through the cAMP-dependent PKA pathway, as confirmed by cell pre-treatment with Myr-PKI. Both A1 and P2Y1 receptor stimulation exacerbated the TGF-β1-driven effects, which were reduced by cell pre-treatment with the MAPK inhibitor PD98059, according to the increased ERK1/2 phosphorylation upon receptor activation. The effects induced by P2Y11 receptor activation were oppositely modulated by PKA or MAPK inhibition, in line with the dual nature of the Gs- and Gq-coupled receptor. Differently, P2X7 receptor induced, per se, similar and not additive effects compared to TGF-β1, after prolonged cell exposure to BzATP. These results suggest a putative role of purine receptors as target for anti-fibrotic agents.

Cadherins function during the collective cell migration of Xenopus Cranial Neural Crest cells: revisiting the role of E-cadherin

Collective cell migration is a process whereby cells move while keeping contact with other cells. The Xenopus Cranial Neural Crest (CNC) is a population of cells that emerge during early embryogenesis and undergo extensive migration from the dorsal to ventral part of the embryo's head. These cells migrate collectively and require cadherin mediated cell-cell contact. In this review, we will describe the key features of Xenopus CNC migration including the key molecules driving their migration. We will also review the role of the various cadherins during Xenopus CNC emergence and migration. Lastly, we will discuss the recent and seemingly controversial findings showing that E-cadherin presence is essential for CNC migration.

Single-Cell Transcriptomic Analysis of Primary and Metastatic Tumor Ecosystems in Head and Neck Cancer

The diverse malignant, stromal, and immune cells in tumors affect growth, metastasis, and response to therapy. We profiled transcriptomes of ∼6,000 single cells from 18 head and neck squamous cell carcinoma (HNSCC) patients, including five matched pairs of primary tumors and lymph node metastases. Stromal and immune cells had consistent expression programs across patients. Conversely, malignant cells varied within and between tumors in their expression of signatures related to cell cycle, stress, hypoxia, epithelial differentiation, and partial epithelial-to-mesenchymal transition (p-EMT). Cells expressing the p-EMT program spatially localized to the leading edge of primary tumors. By integrating single-cell transcriptomes with bulk expression profiles for hundreds of tumors, we refined HNSCC subtypes by their malignant and stromal composition and established p-EMT as an independent predictor of nodal metastasis, grade, and adverse pathologic features. Our results provide insight into the HNSCC ecosystem and define stromal interactions and a p-EMT program associated with metastasis.