The zinc-finger protein slug causes desmosome dissociation, an initial and necessary step for growth factor-induced epithelial-mesenchymal transition

Lack of basic rationale in epithelial-mesenchymal transition and its related concepts

Epithelial-mesenchymal transition (EMT) is defined as a cellular process during which epithelial cells acquire mesenchymal phenotypes and behavior following the downregulation of epithelial features. EMT and its reversed process, the mesenchymal-epithelial transition (MET), and the special form of EMT, the endothelial-mesenchymal transition (EndMT), have been considered as mainstream concepts and general rules driving developmental and pathological processes, particularly cancer. However, discrepancies and disputes over EMT and EMT research have also grown over time. EMT is defined as transition between two cellular states, but it is unanimously agreed by EMT researchers that (1) neither the epithelial and mesenchymal states nor their regulatory networks have been clearly defined, (2) no EMT markers or factors can represent universally epithelial and mesenchymal states, and thus (3) EMT cannot be assessed on the basis of one or a few EMT markers. In contrast to definition and proposed roles of EMT, loss of epithelial feature does not cause mesenchymal phenotype, and EMT does not contribute to embryonic mesenchyme and neural crest formation, the key developmental events from which the EMT concept was derived. EMT and MET, represented by change in cell shapes or adhesiveness, or symbolized by EMT factors, are biased interpretation of the overall change in cellular property and regulatory networks during development and cancer progression. Moreover, EMT and MET are consequences rather than driving factors of developmental and pathological processes. The true meaning of EMT in some developmental and pathological processes, such as fibrosis, needs re-evaluation. EMT is believed to endow malignant features, such as migration, stemness, etc., to cancer cells. However, the core property of cancer (tumorigenic) cells is neural stemness, and the core EMT factors are components of the regulatory networks of neural stemness. Thus, EMT in cancer progression is misattribution of the roles of neural stemness to the unknown mesenchymal state. Similarly, neural crest EMT is misattribution of intrinsic property of neural crest cells to the unknown mesenchymal state. Lack of basic rationale in EMT and related concepts urges re-evaluation of their significance as general rules for understanding developmental and pathological processes, and re-evaluation of their significance in scientific research.

YTHDF3 Regulates the Degradation and Stability of m6A-Enriched Transcripts to Facilitate the Progression of Castration-Resistant Prostate Cancer

RNA N6-methyladenosine (m6A) readers mediate cancer progression. However, the functional role and potential mechanisms of the m6A readers in prostate cancer tumorigenicity remain to be elucidated. In this study, we demonstrate that YTHDF3 expression is elevated in castration-resistant prostate cancer (CRPC) and positively correlated to high grade, bone metastasis and poor survival. YTHDF3 expression promoted CRPC cell proliferation, epithelial to mesenchymal transition (EMT) and tumour progression. Mechanistically, YTHDF3 promoted the RNA degradation of SPOP and NXK3.1 but stabilized RNA expressions of TWIST1 and SNAI2 dependent on m6A to facilitate cell proliferation and EMT. Additionally, YTHDF3 expression enhanced AKT activity via degrading SPOP in an m6A-dependent manner. Importantly, we found that melatonin can compete with m6A to occupy the m6A-binding cage of YTHDF3, leading to inhibition of YTHFD3 and its target expressions as well as CRPC tumour growth. Our findings uncover an essential role of YTHDF3 in the progression of CRPC and highlight the role of melatonin in anti-CRPC activity.

Multifaceted TGF-β signaling, a master regulator: From bench-to-bedside, intricacies, and complexities

Physiological embryogenesis and adult tissue homeostasis are regulated by transforming growth factor-β (TGF-β), an evolutionarily conserved family of secreted polypeptide factors, acting in an autocrine and paracrine manner. The role of TGF-β in inflammation, fibrosis, and cancer is complex and sometimes even contradictory, exhibiting either inhibitory or promoting effects depending on the stage of the disease. Under pathological conditions, especially fibrosis and cancer, overexpressed TGF-β causes extracellular matrix deposition, epithelial-mesenchymal transition, cancer-associated fibroblast formation, and/or angiogenesis. In this review article, we have tried to dive deep into the mechanism of action of TGF-β in inflammation, fibrosis, and carcinogenesis. As TGF-β and its downstream signaling mechanism are implicated in fibrosis and carcinogenesis blocking this signaling mechanism appears to be a promising avenue. However, targeting TGF-β carries substantial risk as this pathway is implicated in multiple homeostatic processes and is also known to have tumor-suppressor functions. There is a need for careful dosing of TGF-β drugs for therapeutic use and patient selection.

Spatial and Temporal Relationship between Epithelial-Mesenchymal Transition (EMT) and Stem Cells in Cancer

BACKGROUND

Epithelial-mesenchymal transition (EMT) is often linked with carcinogenesis. However, EMT is also important for embryo development and only reactivates in cancer. Connecting how EMT occurs during embryonic development and in cancer could help us further understand the root mechanisms of cancer diseases.

CONTENT

There are key regulatory elements that contribute to EMT and the induction and maintenance of stem cell properties during embryogenesis, tissue regeneration, and carcinogenesis. Here, we explore the implications of EMT in the different stages of embryogenesis and tissue development. We especially highlight the necessity of EMT in the mesodermal formation and in neural crest cells. Through EMT, these cells gain epithelial-mesenchymal plasticity (EMP). With this transition, crucial morphological changes occur to progress through the metastatic cascade as well as tissue regeneration after an injury. Stem-like cells, including cancer stem cells, are generated from EMT and during this process upregulate factors necessary for stem cell maintenance. Hence, it is important to understand the key regulators allowing stem cell awakening in cancer, which increases plasticity and promotes treatment resistance, to develop strategies targeting this cell population and improve patient outcomes.

SUMMARY

EMT involves multifaceted regulation to allow the fluidity needed to facilitate adaptation. This regulatory mechanism, plasticity, involves many cooperating transcription factors. Additionally, posttranslational modifications, such as splicing, activate the correct isoforms for either epithelial or mesenchymal specificity. Moreover, epigenetic regulation also occurs, such as acetylation and methylation. Downstream signaling ultimately results in the EMT which promotes tissue generation/regeneration and cancer progression.

Colibactin-producing Escherichia coli enhance resistance to chemotherapeutic drugs by promoting epithelial to mesenchymal transition and cancer stem cell emergence

Human colorectal cancers (CRCs) are readily colonized by colibactin-producing E. coli (CoPEC). CoPEC induces DNA double-strand breaks, DNA mutations, genomic instability, and cellular senescence. Infected cells produce a senescence-associated secretory phenotype (SASP), which is involved in the increase in tumorigenesis observed in CRC mouse models infected with CoPEC. This study investigated whether CoPEC, and the SASP derived from CoPEC-infected cells, impacted chemotherapeutic resistance. Human intestinal epithelial cells were infected with the CoPEC clinical 11G5 strain or with its isogenic mutant, which is unable to produce colibactin. Chemotherapeutic resistance was assessed in vitro and in a xenograft mouse model. Expressions of cancer stem cell (CSC) markers in infected cells were investigated. Data were validated using a CRC mouse model and human clinical samples. Both 11G5-infected cells, and uninfected cells incubated with the SASP produced by 11G5-infected cells exhibited an increased resistance to chemotherapeutic drugs in vitro and in vivo. This finding correlated with the induction of the epithelial to mesenchymal transition (EMT), which led to the emergence of cells exhibiting CSC features. They grew on ultra-low attachment plates, formed colonies in soft agar, and overexpressed several CSC markers (e.g. CD133, OCT-3/4, and NANOG). In agreement with these results, murine and human CRC biopsies colonized with CoPEC exhibited higher expression levels of OCT-3/4 and NANOG than biopsies devoid of CoPEC. Conclusion: CoPEC might aggravate CRCs by inducing the emergence of cancer stem cells that are highly resistant to chemotherapy.

Curcumin and its Derivatives Targeting Multiple Signaling Pathways to Elicit Anticancer Activity: A Comprehensive Perspective

The uncontrolled growth and spread of aberrant cells characterize the group of disorders known as cancer. According to GLOBOCAN 2022 analysis of cancer patients in either developed countries or developing countries the main concern cancers are breast cancer, lung cancer, and liver cancer which may rise eventually. Natural substances with dietary origins have gained interest for their low toxicity, anti-inflammatory, and antioxidant effects. The evaluation of dietary natural products as chemopreventive and therapeutic agents, the identification, characterization, and synthesis of their active components, as well as the enhancement of their delivery and bioavailability, have all received significant attention. Thus, the treatment strategy for concerning cancers must be significantly evaluated and may include the use of phytochemicals in daily lifestyle. In the present perspective, we discussed one of the potent phytochemicals, that has been used over the past few decades known as curcumin as a panacea drug of the "Cure-all" therapy concept. In our review firstly we included exhausted data from in vivo and in vitro studies on breast cancer, lung cancer, and liver cancer which act through various cancer-targeting pathways at the molecular level. Now, the second is the active constituent of turmeric known as curcumin and its derivatives are enlisted with their targeted protein in the molecular docking studies, which help the researchers design and synthesize new curcumin derivatives with respective implicated molecular and cellular activity. However, curcumin and its substituted derivatives still need to be investigated with unknown targeting mechanism studies in depth.

Expression profiling of extramedullary acute myeloid leukemia suggests involvement of epithelial-mesenchymal transition pathways

Extramedullary (EM) colonization is a rare complication of acute myeloid leukemia (AML), occurring in about 10% of patients, but the processes underlying tissue invasion are not entirely characterized. Through the application of RNAseq technology, we examined the transcriptome profile of 13 AMLs, 9 of whom presented an EM localization. Our analysis revealed significant deregulation within the extracellular matrix (ECM)-receptor interaction and focal-adhesion pathways, specifically in the EM sites. The transcription factor TWIST1, which is known to impact on cancer invasion by dysregulating epithelial-mesenchymal-transition (EMT) processes, was significantly upregulated in EM-AML. To test the functional impact of TWIST1 overexpression, we treated OCI-AML3s with TWIST1-siRNA or metformin, a drug known to inhibit tumor progression in cancer models. After 48 h, we showed downregulation of TWIST1, and of the EMT-related genes FN1 and SNAI2. This was associated with significant impairment of migration and invasion processes by Boyden chamber assays. Our study shed light on the molecular mechanisms associated with EM tissue invasion in AML, and on the ability of metformin to interfere with key players of this process. TWIST1 may configure as candidate marker of EM-AML progression, and inhibition of EMT-pathways may represent an innovative therapeutic intervention to prevent or treat this complication.

Cisplatin-induced activation of TGF-β signaling contributes to drug resistance

Growing evidence suggests an association between epithelial-mesenchymal transition (EMT), a hallmark of tumor malignancy, and chemoresistance to a number of anti-cancer drugs. However, the mechanism of EMT induction in the process of acquiring anti-cancer drug resistance remains unclear. To address this issue, we obtained a number of cisplatin-resistant clones from LoVo cells and found that almost all of them lost cell-cell contacts. In these clones, the epithelial marker E-cadherin was downregulated, whereas the mesenchymal marker N-cadherin was upregulated. Moreover, the expression of EMT-related transcription factors, including Slug, was elevated. On the other hand, the upregulation of other mesenchymal marker Vimentin was weak, suggesting that the mesenchymal-like phenotypic changes occurred in these cisplatin-resistant clones. These mesenchymal-like features of cisplatin-resistant clones were partially reversed to parental epithelial-like features by treatment with transforming growth factor-β (TGF-β) receptor kinase inhibitors, indicating that TGF-β signaling is involved in cisplatin-induced the mesenchymal-like phenotypic changes. Moreover, cisplatin was observed to enhance the secretion of TGF-β into the culture media without influencing TGF-β gene transcription. These results suggest that cisplatin may induce the mesenchymal-like phenotypic changes by enhancing TGF-β secretion, ultimately resulting in drug resistance.

Dynamical hallmarks of cancer: Phenotypic switching in melanoma and epithelial-mesenchymal plasticity

Phenotypic plasticity was recently incorporated as a hallmark of cancer. This plasticity can manifest along many interconnected axes, such as stemness and differentiation, drug-sensitive and drug-resistant states, and between epithelial and mesenchymal cell-states. Despite growing acceptance for phenotypic plasticity as a hallmark of cancer, the dynamics of this process remains poorly understood. In particular, the knowledge necessary for a predictive understanding of how individual cancer cells and populations of cells dynamically switch their phenotypes in response to the intensity and/or duration of their current and past environmental stimuli remains far from complete. Here, we present recent investigations of phenotypic plasticity from a systems-level perspective using two exemplars: epithelial-mesenchymal plasticity in carcinomas and phenotypic switching in melanoma. We highlight how an integrated computational-experimental approach has helped unravel insights into specific dynamical hallmarks of phenotypic plasticity in different cancers to address the following questions: a) how many distinct cell-states or phenotypes exist?; b) how reversible are transitions among these cell-states, and what factors control the extent of reversibility?; and c) how might cell-cell communication be able to alter rates of cell-state switching and enable diverse patterns of phenotypic heterogeneity? Understanding these dynamic features of phenotypic plasticity may be a key component in shifting the paradigm of cancer treatment from reactionary to a more predictive, proactive approach.

Tumor heterogeneity from the viewpoint of pathologists

Morphological and functional heterogeneity are found in tumors, with the latter reflecting the different levels of resistance against antitumor therapies. In a therapy-resistant subpopulation, the expression levels of differentiation markers decrease, and those of immature markers increase. In addition, this subpopulation expresses genes involved in drug metabolism, such as aldehyde dehydrogenase 1A1 (ALDH1A1). Because of their similarity to stem cells, cells in the latter therapy-resistant subpopulation are called cancer stem cells (CSCs). Like normal stem cells, CSCs were originally thought not to arise from non-CSCs, but this hierarchical model is too simple. It is now believed that CSCs are generated from non-CSCs. The plasticity of tumor phenotypes between CSCs and non-CSCs causes difficulty in completely curing tumors. In this review, focusing on ALDH1A1 as a marker for CSCs or immature tumor cells, the dynamics of ALDH1A1-expressing tumor cells and their regulatory mechanisms are described, and the plausible regulatory mechanisms of plasticity of ALDH1A1 expression phenotype are discussed. Genetic mutations are a significant factor for tumorigenesis, but non-mutational epigenetic reprogramming factors yielding tumor heterogeneity are also crucial in determining tumor characteristics. Factors influencing non-mutational epigenetic reprogramming in tumors are also discussed.

The epithelial-mesenchymal plasticity landscape: principles of design and mechanisms of regulation

Epithelial-mesenchymal plasticity (EMP) enables cells to interconvert between several states across the epithelial-mesenchymal landscape, thereby acquiring hybrid epithelial/mesenchymal phenotypic features. This plasticity is crucial for embryonic development and wound healing, but also underlies the acquisition of several malignant traits during cancer progression. Recent research using systems biology and single-cell profiling methods has provided novel insights into the main forces that shape EMP, which include the microenvironment, lineage specification and cell identity, and the genome. Additionally, key roles have emerged for hysteresis (cell memory) and cellular noise, which can drive stochastic transitions between cell states. Here, we review these forces and the distinct but interwoven layers of regulatory control that stabilize EMP states or facilitate epithelial-mesenchymal transitions (EMTs) and discuss the therapeutic potential of manipulating the EMP landscape.

Upregulation of SLUG expression in canine mammary gland tumors and its prognostic significance

BACKGROUND

SLUG (also known as snai2), which is a transcription factor in epithelial-mesenchymal transition (EMT), plays an important role in tumorigenesis. Several human studies have revealed that SLUG expression downregulates E-cadherin activity to induce metastasis and invasion of tumor cells, and its association with tumor mechanisms is under constant evaluation. In clinical veterinary medicine, one study revealed upregulated SLUG expression in canine oral squamous cell carcinoma. However, the association between canine mammary gland tumors (MGT), the most common neoplasm in intact female dogs, and SLUG has not been investigated yet. Therefore, this study aimed to evaluate the differences in SLUG expression among canine normal mammary gland tissue and MGTs using immunohistochemistry. In addition, its prognostic significance was evaluated by analyzing the correlation with the Ki-67 proliferation index and various clinicopathological features.

RESULTS

SLUG expression increased substantially from normal mammary gland tissues to MGTs, especially showing the strongest expression in malignant MGT than in benign MGT. Negative SLUG expression was observed in mostly normal mammary gland tissues, whereas all tissues in malignant MGT showed positive SLUG expression. Furthermore, positive SLUG expression was associated with higher Ki-67 index, larger tumor size (> 3 cm), and metastasis. Kaplan-Meier survival curve analysis revealed that positive SLUG expression was significantly associated with poor overall and disease-free survival.

CONCLUSIONS

These results indicate that SLUG is upregulated in canine MGTs and positive SLUG expression is positively correlated with poor prognosis. Thus, SLUG protein can be a novel biomarker and therapeutic target for canine patients with MGT.

An "unexpected" role for EMT transcription factors in hematological development and malignancy

The epithelial to mesenchymal transition (EMT) is a fundamental developmental process essential for normal embryonic development. It is also important during various pathogenic processes including fibrosis, wound healing and epithelial cancer cell metastasis and invasion. EMT is regulated by a variety of cell signalling pathways, cell-cell interactions and microenvironmental cues, however the key drivers of EMT are transcription factors of the ZEB, TWIST and SNAIL families. Recently, novel and unexpected roles for these EMT transcription factors (EMT-TFs) during normal blood cell development have emerged, which appear to be largely independent of classical EMT processes. Furthermore, EMT-TFs have also begun to be implicated in the development and pathogenesis of malignant hematological diseases such as leukemia and lymphoma, and now present themselves or the pathways they regulate as possible new therapeutic targets within these malignancies. In this review, we discuss the ZEB, TWIST and SNAIL families of EMT-TFs, focusing on what is known about their normal roles during hematopoiesis as well as the emerging and "unexpected" contribution they play during development and progression of blood cancers.

Nucleobindin-2 mediates TGF-β1-driven phenotypes in ZEB1-high uterine carcinosarcoma

Epithelial-mesenchymal transition (EMT) is a hallmark of uterine carcinosarcoma (UCS). Here, we used shotgun proteomics analysis to identify biomarkers associated with blebbistatin-mediated EMT in UCS, and found upregulation of nucleobindin-2 (NUCB2) in endometrial carcinoma (Em Ca) cells. Expression of N-cadherin, Snail, Slug, and ZEB1, was reduced in NUCB2 knockout Em Ca cells, whereas ZEB1, Twist1, and vimentin were upregulated in NUCB2-overexpressing Em Ca cells. NUCB2 knockout reduced cell proliferation and migration, whereas NUCB2 overexpression had the opposite effect. Treatment of Em Ca cells with TGF-β1 dramatically altered morphology toward a fibroblastic appearance; concomitantly, expression of NUCB2 and ZEB1 increased. The NUCB2 promoter was also activated by transfection of Smad2. In UCS tissues, NUCB2 expression was significantly higher in sarcomatous as compared to carcinomatous components; this was consistent with increased TGF-β1 mRNA expression in stromal and sarcomatous components as compared to carcinomatous components. In addition, NUCB2 score correlated positively with ZEB1 and vimentin scores, whereas ZEB1 score correlated positively with Slug and vimentin scores and inversely with the E-cadherin score. We therefore suggest that TGF-β-dependent upregulation of NUCB2 and ZEB1 contributes to the phenotypic characteristics of sarcomatous components in UCS.

LncRNA-NONMMUT100923.1 regulates mouse embryonic palatal shelf adhesion by sponging miR-200a-3p to modulate medial epithelial cell desmosome junction during palatogenesis

Cleft palate (CP) is a common neonatal craniofacial defect caused by the adhesion and fusion dysfunction of bilateral embryonic palatal shelf structures. Long non-coding RNA (lncRNA) is involved in CP formation with regulatory mechanism unknown. In this study, all-trans retinoic acid (ATRA) was used to induced cleft palate in embryonic mice as model group. The RNA-sequencing was performed to screen differentially expressed genes between the normal and model group on embryonic day 16.5, and the expression of LncRNA-NONMMUT100923.1 and miR-200a-3p, Cdsn was confirmed by RT-PCR and western blotting. Colony formation, CCK-8 and EDU assays were performed to measure cell proliferation and apoptosis on mouse embryonic palatal shelf (MEPS) epithelial cells in vitro. Fluorescence in situ hybridization (FISH) and dual luciferase activity assays was used to investigate the regulatory effect of LncRNA-NONMMUT100923.1 on miRNA and its target genes. Up-regulation of LncRNA-NONMMUT100923.1 and Cdsn while downregulation of miR-200a-3p was found in the model group. The sponging effects of LncRNA-NONMMUT100923 on miR-200a-3p and the target gene relations between Cdsn and miR-200a-3p was confirmed. Low expression of miR-200a-3p was related to the increased expressed levels of Cdsn and the proliferation of MEPS epithelial cells. Thus, a potential ceRNA regulatory network in which LncRNA-NONMMUT100923.1 regulates Cdsn expression by competitively binding to endogenous miR-200a-3p during palatogenesis, which may inhibit MEPS adhesion by preventing the disintegration of the desmosome junction in medial edge epithelium cells. These findings indicate the regulatory role of lncRNA and provides a potential direction for target gene therapy of CP.

Drug-Induced Gingival Overgrowth-Molecular Aspects of Drug Actions

Drug-induced gingival overgrowth (DIGO) is one of the side effects produced by therapeutic agents, most commonly phenytoin, nifedipine and cyclosporin A. However, the precise mechanism of DIGO is not entirely understood. A literature search of the MEDLINE/PubMed databases was conducted to identify the mechanisms involved in DIGO. The available information suggests that the pathogenesis of DIGO is multifactorial, but common pathogenic sequelae of events emerge, i.e., sodium and calcium channel antagonism or disturbed intracellular handling of calcium, which finally lead to reductions in intracellular folic acid levels. Disturbed cellular functions, mainly in keratinocytes and fibroblasts, result in increased collagen and glycosaminoglycans accumulation in the extracellular matrix. Dysregulation of collagenase activity, as well as integrins and membrane receptors, are key mechanisms of reduced degradation or excessive synthesis of connective tissue components. This manuscript describes the cellular and molecular factors involved in the epithelial-mesenchymal transition and extracellular matrix remodeling triggered by agents producing DIGO.

Harnessing epithelial-mesenchymal plasticity to boost cancer immunotherapy

Immune checkpoint blockade (ICB) therapy is a powerful option for cancer treatment. Despite demonstrable progress, most patients fail to respond or achieve durable responses due to primary or acquired ICB resistance. Recently, tumor epithelial-to-mesenchymal plasticity (EMP) was identified as a critical determinant in regulating immune escape and immunotherapy resistance in cancer. In this review, we summarize the emerging role of tumor EMP in ICB resistance and the tumor-intrinsic or extrinsic mechanisms by which tumors exploit EMP to achieve immunosuppression and immune escape. We discuss strategies to modulate tumor EMP to alleviate immune resistance and to enhance the efficiency of ICB therapy. Our discussion provides new prospects to enhance the ICB response for therapeutic gain in cancer patients.

Tannic Acid, A Hydrolysable Tannin, Prevents Transforming Growth Factor-β-Induced Epithelial-Mesenchymal Transition to Counteract Colorectal Tumor Growth

Despite the medico-surgical progress that has been made in the management of patients with colorectal cancer (CRC), the prognosis at five years remains poor. This resistance of cancer cells partly results from their phenotypic characteristics in connection with the epithelial-mesenchymal transition (EMT). In the present study, we have explored the ability of a polyphenol, tannic acid (TA), to counteract CRC cell proliferation and invasion through an action on the EMT. We highlight that TA decreases human SW480 and SW620 CRC cell and murine CT26 CRC cell viability, and TA inhibits their adhesion in the presence of important factors comprising the extracellular matrix, particularly in the presence of collagen type I and IV, and fibronectin. Moreover, these properties were associated with TA's ability to disrupt CRC cell migration and invasion, which are induced by transforming growth factor-β (TGF-β), as evidence in the video microscopy experiments showing that TA blocks the TGF-β1-induced migration of SW480 and CT26 cells. At the molecular level, TA promotes a reversal of the epithelial-mesenchymal transition by repressing the mesenchymal markers (i.e., Slug, Snail, ZEB1, and N-cadherin) and re-expressing the epithelial markers (i.e., E-cadherin and β-catenin). These effects could result from a disruption of the non-canonical signaling pathway that is induced by TGF-β1, where TA strongly decreases the phosphorylation of extracellular-signal regulated kinase ERK1/2, P38 and the AKT proteins that are well known to contribute to the EMT, the cell motility, and the acquisition of invasive properties by tumor cells. Very interestingly, a preclinical study of mice with subcutaneous murine tumor colon CT26 cells has shown that TA was able to significantly delay the growth of tumors without hepato- and nephrotoxicities.

CDCA7 promotes TGF-β-induced epithelial-mesenchymal transition via transcriptionally regulating Smad4/Smad7 in ESCC

Cell division cycle associated 7 (CDCA7) is a copy number amplification gene that contributes to the metastasis and invasion of tumors, including esophageal squamous cell carcinoma (ESCC). This present study aimed at clarifying whether high expression of CDCA7 promotes the metastasis and invasion of ESCC cell lines and exploring the underlying mechanisms implicated in epithelial-mesenchymal transition (EMT) of ESCC. The role of CDCA7 in the regulation of ESCC metastasis and invasion was evaluated using ESCC cell lines. Expression of EMT-related markers including E-cadherin, N-cadherin, Vimentin, Snail, and Slug, transforming growth factor β (TGF-β) signaling pathway including Smad2/3, p-Smad2/3, Smad4, and Smad7 were detected in CDCA7 knockdown and overexpressed cell lines. Dual-luciferase reporter assay and rescue assay were used to explore the underlying mechanisms that CDCA7 contributed to the metastasis and invasion of ESCC. High CDCA7 expression significantly promoted the metastasis and invasion of ESCC cell lines both in vivo and in vitro. Additionally, the expression of CDCA7 positively correlated with the expression of N-cadherin, Vimentin, Snail, Slug, TGF-β signaling pathway and negatively correlated with the expression of E-cadherin. Furthermore, CDCA7 transcriptionally regulated the expression of Smad4 and Smad7. Knockdown of CDCA7 inhibited the TGF-β signaling pathway and therefore inhibited EMT. Our data indicated that CDCA7 was heavily involved in EMT by regulating the expression of Smad4 and Smad7 in TGF-β signaling pathway. CDCA7 might be a new therapeutic target in the suppression of metastasis and invasion of ESCC.

Pathogenesis of periodontitis - A potential role for epithelial-mesenchymal transition

Epithelial mesenchymal transition (EMT) is a process comprising cellular and molecular events which result in cells shifting from an epithelial to a mesenchymal phenotype. Periodontitis is a destructive chronic disease of the periodontium initiated in response to a dysbiotic microbiome, and dominated by Gram-negative bacteria in the subgingival niches accompanied by an aberrant immune response in susceptible subjects. Both EMT and periodontitis share common risk factors and drivers, including Gram-negative bacteria, excess inflammatory cytokine production, smoking, oxidative stress and diabetes mellitus. In addition, periodontitis is characterized by down-regulation of key epithelial markers such as E-cadherin together with up-regulation of transcriptional factors and mesenchymal proteins, including Snail1, vimentin and N-cadherin, which also occur in the EMT program. Clinically, these phenotypic changes may be reflected by increases in microulceration of the pocket epithelial lining, granulation tissue formation, and fibrosis. Both in vitro and in vivo data now support the potential involvement of EMT as a pathogenic mechanism in periodontal diseases which may facilitate bacterial invasion into the underlying gingival tissues and propagation of inflammation. This review surveys the available literature and provides evidence linking EMT to periodontitis pathogenesis.

WNK1–OSR1 Signaling Regulates Angiogenesis-Mediated Metastasis towards Developing a Combinatorial Anti-Cancer Strategy

Lysine-deficient protein kinase-1 (WNK1) is critical for both embryonic angiogenesis and tumor-induced angiogenesis. However, the downstream effectors of WNK1 during these processes remain ambiguous. In this study, we identified that oxidative stress responsive 1b (osr1b) is upregulated in endothelial cells in both embryonic and tumor-induced angiogenesis in zebrafish, accompanied by downregulation of protein phosphatase 2A (pp2a) subunit ppp2r1bb. In addition, wnk1a and osr1b are upregulated in two liver cancer transgenic fish models: [tert x p53^−/−] and [HBx,src,p53^−/−,RPIA], while ppp2r1bb is downregulated in [tert x p53^−/−]. Furthermore, using HUVEC endothelial cells co-cultured with HepG2 hepatoma cells, we confirmed that WNK1 plays a critical role in the induction of hepatoma cell migration in both endothelial cells and hepatoma cells. Moreover, overexpression of OSR1 can rescue the reduced cell migration caused by shWNK1 knockdown in HUVEC cells, indicating OSR1 is downstream of WNK1 in endothelial cells promoting hepatoma cell migration. Overexpression of PPP2R1A can rescue the increased cell migration caused by WNK1 overexpression in HepG2, indicating that PPP2R1A is a downstream effector in hepatoma. The combinatorial treatment with WNK1 inhibitor (WNK463) and OSR1 inhibitor (Rafoxanide) plus oligo-fucoidan via oral gavage to feed [HBx,src,p53^−/−,RPIA] transgenic fish exhibits much more significant anticancer efficacy than Regorafenib for advanced HCC. Importantly, oligo-fucoidan can reduce the cell senescence marker-IL-1β expression. Furthermore, oligo-fucoidan reduces the increased cell senescence-associated β-galactosidase activity in tert transgenic fish treated with WNK1-OSR1 inhibitors. Our results reveal the WNK1–OSR1–PPP2R1A axis plays a critical role in both endothelial and hepatoma cells during tumor-induced angiogenesis promoting cancer cell migration. By in vitro and in vivo experiments, we further uncover the molecular mechanisms of WNK1 and its downstream effectors during tumor-induced angiogenesis. Targeting WNK1–OSR1-mediated anti-angiogenesis and anti-cancer activity, the undesired inflammation response caused by inhibiting WNK1–OSR1 can be attenuated by the combination therapy with oligo-fucoidan and may improve the efficacy.

Toxic metals in the regulation of epithelial-mesenchymal plasticity: demons or angels?

Epithelial cells can trans-differentiate into motile mesenchymal cells through a dynamic process known as epithelial-mesenchymal transition (EMT). EMT is crucial in embryonic development and wound healing but also contributes to human diseases such as organ fibrosis and cancer progression. Heavy metals are environmental pollutants that can affect human health in various ways, including causing cancers. The cytotoxicity and carcinogenicity of heavy metals are complex, and studies have demonstrated that some of these metals can affect the progress of EMT. Here, we focus on reviewing the roles of six environmentally common toxic metals concerning EMT: arsenic (AS), cadmium (Cd), cobalt (Co), chromium (Cr), nickel (Ni), and copper (Cu). Noteworthily, the effects of these elements on EMT may vary according to the form, dose, and exposure time; the dual role of heavy metals (e.g., AS, Cd, and Cu) on EMT is also observed, in which, sometimes they can promote while sometimes inhibit the EMT process. Given the vast number of toxicologically relevant metals that exist in nature, we believe a comprehensive understanding of their effects on EMT is required to dictate in what circumstances these metals act more likely as demons or angels.

Epithelial-Mesenchymal Plasticity in Tumor Immune Evasion

Epithelial-mesenchymal transition (EMT) is a fundamental process that occurs during embryogenesis and tissue repair. However, EMT can be hijacked by malignant cells, where it may promote immune evasion and metastasis. Classically considered a dichotomous transition, EMT in cancer has recently been considered a plastic process whereby malignant cells display and interconvert among hybrid epithelial/mesenchymal (E/M) states. Epithelial-mesenchymal plasticity (EMP) and associated hybrid E/M states are divergent from classical EMT, with unique immunomodulatory effects. Here, we review recent insights into the EMP-immune cross-talk, highlighting possible mechanisms of immune evasion conferred by hybrid E/M states and roles of immune cells in EMP.

Ubiquitination and deubiquitination in the regulation of epithelial-mesenchymal transition in cancer: Shifting gears at the molecular level

The process of conversion of non-motile epithelial cells to their motile mesenchymal counterparts is known as epithelial-mesenchymal transition (EMT), which is a fundamental event during embryonic development, tissue repair, and for the maintenance of stemness. However, this crucial process is hijacked in cancer and becomes the means by which cancer cells acquire further malignant properties such as increased invasiveness, acquisition of stem cell-like properties, increased chemoresistance, and immune evasion ability. The switch from epithelial to mesenchymal phenotype is mediated by a wide variety of effector molecules such as transcription factors, epigenetic modifiers, post-transcriptional and post-translational modifiers. Ubiquitination and de-ubiquitination are two post-translational processes that are fundamental to the ubiquitin-proteasome system (UPS) of the cell, and the shift in equilibrium between these two processes during cancer dictates the suppression or activation of different intracellular processes, including EMT. Here, we discuss the complex and dynamic relationship between components of the UPS and EMT in cancer.

Vestigial-like family member 3 stimulates cell motility by inducing high-mobility group AT-hook 2 expression in cancer cells

Vestigial‐like family member 3 (VGLL3) is a cofactor for TEA domain transcription factors (TEADs). Although VGLL3 is known to be highly expressed and stimulate cell proliferation in mesenchymal cancer cells, its involvement in mesenchymal phenotypes is largely unknown. In this study, we found that VGLL3 promotes epithelial‐to‐mesenchymal transition (EMT)‐like phenotypic changes. We found that A549 human lung cancer cells stably expressing VGLL3 exhibit spindle‐like morphological changes, reduction in the epithelial marker E‐cadherin and induction of the mesenchymal marker Snail. Notably, VGLL3‐expressing cells exhibited enhanced motility. The DNA‐binding protein high‐mobility group AT‐hook 2 (HMGA2) was found to be a target of the VGLL3‐TEAD4 complex, and HMGA2 knockdown repressed EMT‐like phenotypic changes in VGLL3‐expressing cells. VGLL3‐dependent phenotypic changes are involved in transforming growth factor‐β (TGF‐β)‐induced EMT progression. VGLL3 or HMGA2 knockdown repressed the motility of the mesenchymal breast cancer MDA‐MB‐231 cells. Importantly, high levels of VGLL3 expression were shown to have a positive correlation with poor prognosis in various human cancers, such as breast, colon, ovarian, head and neck, pancreatic, renal, gastric and cervical cancers. These results suggest that VGLL3 promotes EMT‐like cell motility by inducing HMGA2 expression and accelerates cancer progression.

The Mammary Gland: Basic Structure and Molecular Signaling during Development

The mammary gland is a compound, branched tubuloalveolar structure and a major characteristic of mammals. The mammary gland has evolved from epidermal apocrine glands, the skin glands as an accessory reproductive organ to support postnatal survival of offspring by producing milk as a source of nutrition. The mammary gland development begins during embryogenesis as a rudimentary structure that grows into an elementary branched ductal tree and is embedded in one end of a larger mammary fat pad at birth. At the onset of ovarian function at puberty, the rudimentary ductal system undergoes dramatic morphogenetic change with ductal elongation and branching. During pregnancy, the alveolar differentiation and tertiary branching are completed, and during lactation, the mature milk-producing glands eventually develop. The early stages of mammary development are hormonal independent, whereas during puberty and pregnancy, mammary gland development is hormonal dependent. We highlight the current understanding of molecular regulators involved during different stages of mammary gland development.

The Role of Tumor Stem Cell Exosomes in Cancer Invasion and Metastasis

Exosomes are lipid membrane bilayer-encapsulated vesicles secreted by cells into the extracellular space. They carry abundant inclusions (such as nucleic acids, proteins, and lipids) that play pivotal roles in intercellular communication. Tumor stem cells are capable of self-renewal and are crucial for survival, proliferation, drug resistance, metastasis, and recurrence of tumors. The miRNAs (microRNAs) in exosomes have various functions, such as participating in inflammatory response, cell migration, proliferation, apoptosis, autophagy, and epithelial-mesenchymal transition. Tumor stem cells secrete exosomes that act as important messengers involved in various tumor processes and several studies provide increasing evidence supporting the importance of these exosomes in tumor recurrence and metastasis. This review primarily focuses on the production and secretion of exosomes from tumors and tumor stem cells and their effects on cancer progression. Cancer stem cancer derived exosome play an important massager in the tumor microenvironment. It also emphasizes on the study of tumor stem cell exosomes in the light of cancer metastasis and recurrence aiming to provide valuable insights and novel perspectives, which could be beneficial for developing effective diagnostic and treatment strategies.

Emerging Biomarkers for Early Detection of Chronic Kidney Disease

Chronic kidney disease (CKD) is a major and serious global health problem that leads to kidney damage as well as multiple systemic diseases. Early diagnosis and treatment are two major measures to prevent further deterioration of kidney function and to delay adverse outcomes. However, the paucity of early, predictive and noninvasive biomarkers has undermined our ability to promptly detect and treat this common clinical condition which affects more than 10% of the population worldwide. Despite all limitations, kidney function is still measured by serum creatinine, cystatin C, and albuminuria, as well as estimating glomerular filtration rate using different equations. This review aims to provide comprehensive insight into diagnostic methods available for early detection of CKD. In the review, we discuss the following topics: (i) markers of glomerular injury; (ii) markers of tubulointerstitial injury; (iii) the role of omics; (iv) the role of microbiota; (v) and finally, the role of microRNA in the early detection of CKD. Despite all novel findings, none of these biomarkers have met the criteria of an ideal early marker. Since the central role in CKD progression is the proximal tubule (PT), most data from the literature have analyzed biomarkers of PT injury, such as KIM-1 (kidney injury molecule-1), NGAL (neutrophil gelatinase-associated lipocalin), and L-FABP (liver fatty acid-binding protein).

COL11A1-Driven Epithelial-Mesenchymal Transition and Stemness of Pancreatic Cancer Cells Induce Cell Migration and Invasion by Modulating the AKT/GSK-3β/Snail Pathway

BACKGROUND

Collagen type XI α1 (COL11A1) is associated with tumorigenesis and development in many human malignancies. Previous reports indicate that COL11A1 may be a significant diagnostic marker for pancreatic ductal adenocarcinoma (PDAC); however, its biological role in PDAC progression remains unclear. In this study, we investigated the influence of COL11A1 on the invasion and migration abilities of pancreatic cancer cells and explored its potential molecular mechanisms.

METHODS

Cell migration and invasion were assessed using Transwell assays in pancreatic cancer cells transfected with siCOL11A1 and pCNV3-COL11A1 plasmids. The protein and mRNA expression levels of N-cadherin, E-cadherin, Vimentin, cluster of differentiation (CD)-24, CD44, serine-threonine kinase (AKT), glycogen synthase kinase (GSK)-3β, phospho (p)-AKTSer473, p-GSK-3βSer9, and Snail were analyzed using Western blotting and real-time polymerase chain reaction (PCR). The effect of COL11A1 on cell stemness was tested using flow cytometry and clone formation assays.

RESULTS

These results demonstrated that COL11A1 significantly promoted the invasion and migration abilities of PDAC cells. Furthermore, COL11A1 facilitated the occurrence of epithelial-mesenchymal transition (EMT) and cell stemness by upregulating the expression levels of p-AKTSer473, p-GSK-3βSer9, and Snail.

CONCLUSIONS

This study suggests that the activation of the AKT/GSK-3β/Snail signaling pathway induced by COL11A1 plays a major role in the progression of PDAC. Therefore, COL11A1 could serve as a potential target for PDAC treatment.

Different Expression Levels of DLK2 Inhibit NOTCH Signaling and Inversely Modulate MDA-MB-231 Breast Cancer Tumor Growth In Vivo

NOTCH signaling is implicated in the development of breast cancer tumors. DLK2, a non-canonical inhibitor of NOTCH signaling, was previously shown to be involved in skin and breast cancer. In this work, we studied whether different levels of DLK2 expression influenced the breast cancer characteristics of MDA-MB-231 cells. We found that DLK2 overexpression inhibited NOTCH activation in a dose-dependent manner. Moreover, depending on the level of inhibition of NOTCH1 activation generated by different levels of DLK2 expression, cell proliferation, cell cycle dynamics, cell apoptosis, cell migration, and tumor growth in vivo were affected in opposite directions. Low levels of DLK2 expression produced a slight inhibition of NOTCH1 activation, and enhanced MDA-MB-231 cell invasion in vitro and cell proliferation both in vitro and in vivo. In contrast, MDA-MB-231 cells expressing elevated levels of DLK2 showed a strong inhibition of NOTCH1 activation, decreased cell proliferation, increased cell apoptosis, and were unable to generate tumors in vivo. In addition, DLK2 expression levels also affected some members of other cell signaling pathways implicated in cancer, such as ERK1/2 MAPK, AKT, and rpS6 kinases. Our data support an important role of DLK2 as a protein that can finely regulate NOTCH signaling and affect the tumor properties and growth dynamics of MDA-MB-231 breast cancer cells.

Androgen down-regulates desmocollin 2 in association with induction of mesenchymal transition of breast MDA-MB-453 cancer cells

Desmosomes are cellular structures that are critical in cell-cell adhesion and in maintaining tissue architecture. Changes in the expression of desmocollin-2 (DSC2) have been noted during tumor progression into an invasive phenotype and as cells undergo epithelial-mesenchymal transition. We have previously reported that breast MDA-MB-453 cancer cells, a luminal androgen receptor model of triple-negative breast cancer, acquire mesenchymal features when treated with the androgen receptor (AR) agonist, dihydrotestosterone (DHT). We have therefore investigated androgen regulation of the expression and cellular localization of DSC2 in MDA-MB-453 cells. Treatment of the cells with DHT resulted in a dose-dependent reduction in DSC2 protein levels and dispersion of its membrane localization concomitant with AR- and β-catenin-mediated mesenchymal transition of cells. A significant correlation was revealed between decreased expression of AR and increased expression of DSC2 in patient samples. In addition, whereas lower expression of AR was associated with a reduced overall and recurrence-free survival of breast cancer patients, higher expression of DSC2 was found in invasive breast tumors than in normal breast cells and was correlated with lower patient survival. Upon knocking down DSC2, the cells became elongated, mesenchymal-like, and slightly, but insignificantly, more migratory. The addition of DHT further stimulated cell elongation and migration. DSC2 siRNA-transfected cells reverted to a normal epithelial morphology upon inhibition of β-catenin. These results highlight the role of DSC2 in maintaining the epithelial morphology of MDA-MB-453 cells and the negative regulation of the desmosomal protein by DHT during stimulation of the androgen-induced, β-catenin-mediated mesenchymal transition of the cells. This article is protected by copyright. All rights reserved.

Epithelial-Mesenchymal Transition and Cancer Stem Cells

Epithelial-mesenchymal transition (EMT), a cellular phenotypic change from epithelial to mesenchymal-like features, is related to the resistance and metastasis of cancer stem cells (CSCs). Several signal transduction mechanisms induce EMT, which causes the gene expression alteration to induce the acquisition of resistance and metastasis in cancer. EMT is characterized with high gene expression of cadherin 2 (N-cadherin) and vimentin, and sparse cell-cell junction. The cells with EMT-phenotype have migration, metastasis and drug-resistance capacity, which are main characteristics of CSCs. It seems that the main population of CSCs exhibits EMT phenotype, whereas some populations consist of phenotypes other than EMT. In this chapter, EMT mechanism, phenotypic features of EMT and CSCs, signal transduction in EMT and CSCs, differences between EMT and CSCs, and the role of EMT in CSCs are described.

Desmosome dualism - most of the junction is stable, but a plakophilin moiety is persistently dynamic

Desmosomes, strong cell-cell junctions of epithelia and cardiac muscle, link intermediate filaments to cell membranes and mechanically integrate cells across tissues, dissipating mechanical stress. They comprise five major protein classes - desmocollins and desmogleins (the desmosomal cadherins), plakoglobin, plakophilins and desmoplakin - whose individual contribution to the structure and turnover of desmosomes is poorly understood. Using live-cell imaging together with fluorescence recovery after photobleaching (FRAP) and fluorescence loss and localisation after photobleaching (FLAP), we show that desmosomes consist of two contrasting protein moieties or modules: a very stable moiety of desmosomal cadherins, desmoplakin and plakoglobin, and a highly mobile plakophilin (Pkp2a). As desmosomes mature from Ca2+ dependence to Ca2+-independent hyper-adhesion, their stability increases, but Pkp2a remains highly mobile. We show that desmosome downregulation during growth-factor-induced cell scattering proceeds by internalisation of whole desmosomes, which still retain a stable moiety and highly mobile Pkp2a. This molecular mobility of Pkp2a suggests a transient and probably regulatory role for Pkp2a in desmosomes. This article has an associated First Person interview with the first author of the paper.

Combination of nigericin with cisplatin enhances the inhibitory effect of cisplatin on epithelial ovarian cancer metastasis by inhibiting slug expression via the Wnt/β-catenin signalling pathway

Epithelial ovarian cancer (EOC) is the most lethal cancer among female genital tumours. Standard therapies, including postoperative chemotherapy, exhibit high proportions of recurrence and resistance. Novel therapeutic strategies are combined with chemotherapy. Emerging studies have demonstrated that nigericin, an H⁺, K⁺ and Pb²⁺ ionophore, exhibits promising anticancer activity in various types of malignancy, such as colorectal and epithelial ovarian cancer. Our previous study suggested that nigericin could regulate EOC cell proliferation, migration and invasion, and may be a novel chemotherapy candidate for EOC. However, to the best of our knowledge, the effects of combined therapy with cisplatin, and the associated underlying mechanisms, are not yet fully understood. The present study aimed to clarify the effects of combined chemical therapy with nigericin and cisplatin on EOC cells and to reveal its mechanism. Wound healing, Transwell, cell viability and colony formation assays were used to measure the migration, invasion and proliferation of EOC cells. Western blotting was used to detect protein expression. A slug overexpression lentivirus was used to create a slug overexpression model in SK-OV-3 cells. Small interfering RNA was used to knock down slug expression. Nigericin combined with cisplatin enhanced the inhibitory effects of cisplatin on the migration and colony formation of EOC cells. Nigericin also enhanced the inhibitory effects of cisplatin on the expression levels of MMP7, as well as the inhibitory effects of cisplatin on the expression levels of β-catenin and GSK-3β, indicating that nigericin and cisplatin regulated in the Wnt/β-catenin signalling pathway. When slug was knocked down, the effect of nigericin was weakened. Overexpression of slug could repress the inhibitory effect of nigericin on the Wnt/β-catenin signalling pathway. Furthermore, nigericin inhibited slug expression by enhancing its modification through small ubiquitin-like modifiers (SUMOs; referred to as SUMOylation). Overall, the present results demonstrated that nigericin combined with cisplatin might serve as a novel therapeutic strategy in patients with metastatic EOC because the combined therapy had higher effectiveness than single drug use. The underlying mechanism of combined therapy maybe the enhanced inhibitory effect of slug through its nigericin-induced SUMOylation.

Loss of SNAI2 in Prostate Cancer Correlates With Clinical Response to Androgen Deprivation Therapy

PURPOSE

Androgen receptor (AR) signaling is important in prostate cancer progression, and therapies that target this pathway have been the mainstay of treatment for advanced disease for over 70 years. Tumors eventually progress despite castration through a number of well-characterized mechanisms; however, little is known about what determines the magnitude of response to short-term pathway inhibition.

METHODS

We evaluated a novel combination of AR-targeting therapies (degarelix, abiraterone, and bicalutamide) and noted that the objective patient response to therapy was highly variable. To investigate what was driving treatment resistance in poorly responding patients, as a secondary outcome we comprehensively characterized pre- and post-treatment samples using both whole-genome and RNA sequencing.

RESULTS

We find that resistance following short-term treatment differs molecularly from typical progressive castration-resistant disease, associated with transcriptional reprogramming, to a transitional epithelial-to-mesenchymal transition (EMT) phenotype rather than an upregulation of AR signaling. Unexpectedly, tolerance to therapy appears to be the default state, with treatment response correlating with the prevalence of tumor cells deficient for SNAI2, a key regulator of EMT reprogramming.

CONCLUSION

We show that EMT characterizes acutely resistant prostate tumors and that deletion of SNAI2, a key transcriptional regulator of EMT, correlates with clinical response.

The Post-Translational Regulation of Epithelial-Mesenchymal Transition-Inducing Transcription Factors in Cancer Metastasis

Epithelial-mesenchymal transition (EMT) is generally observed in normal embryogenesis and wound healing. However, this process can occur in cancer cells and lead to metastasis. The contribution of EMT in both development and pathology has been studied widely. This transition requires the up- and down-regulation of specific proteins, both of which are regulated by EMT-inducing transcription factors (EMT-TFs), mainly represented by the families of Snail, Twist, and ZEB proteins. This review highlights the roles of key EMT-TFs and their post-translational regulation in cancer metastasis.

TGF-β-induced α-SMA expression is mediated by C/EBPβ acetylation in human alveolar epithelial cells

BACKGROUND

Although the morbidity and mortality rates associated with idiopathic pulmonary fibrosis (IPF) are high, there is still lack of powerful and precise therapeutic options for IPF.

OBJECT

Through in vitro model, this study sought to determine whether binding of acetylated CCAAT/enhancer binding protein β (C/EBPβ) to alpha-smooth muscle actin (α-SMA) promoter could affect the activity of the latter as well as assess if it is essential for epithelial-to-mesenchymal transition (EMT) and extracellular matrix deposition in IPF.

METHODS

The expression of EMT and C/EBPβ in A549 cells treated with transforming growth factor-beta (TGF-β) as pulmonary fibrotic model was detected by western blotting and qPCR. Collagen-I expression using ELISA was performed. The luciferase activity was used to examine the activity of C/EBPβ. Knockdown of C/EBPβ was performed by siRNA. We also investigated the effect of deacetylation of C/EBPβ on EMT using sirtuin 1 (SIRT1). The binding ability of C/EBPβ with α-SMA promoter was affirmed via chromatin immunoprecipitation (ChIP) and electrophoresis mobility shift assay (EMSA). The relationship between α-SMA and acetylated C/EBPβ was determined with co-immunoprecipitation (Co-IP). SiRNA-mediated knockdown of C/EBPβ in A549 cells attenuated TGF-β1-induced myofibroblast differentiation and ECM deposition. The extent of association between acetylated C/EBPβ and α-SMA promoter was dynamically monitored.

RESULTS

It was confirmed that deacetylation of C/EBPβ in A549 cells successfully ameliorated TGF-β1-induced EMT, as shown by reduction in α-SMA expression and excessive collagen-I accumulation.

CONCLUSION

The EMT and fibrotic effect of TGF-β1 is dependent on acetylated C/EBPβ-mediated regulation of α-SMA gene activity. Thus, C/EBPβ acetylation may play a central role in pulmonary fibrosis.

A Computational Systems Biology Approach Identifies SLUG as a Mediator of Partial Epithelial-Mesenchymal Transition (EMT)

Epithelial-mesenchymal plasticity comprises reversible transitions among epithelial, hybrid epithelial/mesenchymal (E/M) and mesenchymal phenotypes, and underlies various aspects of aggressive tumor progression such as metastasis, therapy resistance, and immune evasion. The process of cells attaining one or more hybrid E/M phenotypes is termed as partial epithelial mesenchymal transition (EMT). Cells in hybrid E/M phenotype(s) can be more aggressive than those in either fully epithelial or mesenchymal state. Thus, identifying regulators of hybrid E/M phenotypes is essential to decipher the rheostats of phenotypic plasticity and consequent accelerators of metastasis. Here, using a computational systems biology approach, we demonstrate that SLUG (SNAIL2) - an EMT-inducing transcription factor - can inhibit cells from undergoing a complete EMT and thus stabilize them in hybrid E/M phenotype(s). It expands the parametric range enabling the existence of a hybrid E/M phenotype, thereby behaving as a phenotypic stability factor. Our simulations suggest that this specific property of SLUG emerges from the topology of the regulatory network it forms with other key regulators of epithelial-mesenchymal plasticity. Clinical data suggest that SLUG associates with worse patient prognosis across multiple carcinomas. Together, our results indicate that SLUG can stabilize hybrid E/M phenotype(s).

High Expression of the Component 3a Receptor 1 (C3AR1) Gene in Stomach Adenocarcinomas Infers a Poor Prognosis and High Immune-Infiltration Levels

Background

This study was designed to explore the incompletely investigated role of the complement component 3a receptor 1 (C3AR1) in the prognosis of stomach adenocarcinomas (STAD).

Material/Methods

Using bioinformatic methods, we systematically determined the expression and prognosis value of C3AR1 in various cancers by using the TIMER (Tumor Immune Estimation Resource) database, UALCAN platform, GEPIA (Gene Expression Profiling Interactive Analysis) server, and the OncoLnc tool. The biological processes influenced by C3AR1 were determined using the GSEA (Gene Set Enrichment Analysis) software (Copyright 2004–2020 Broad Institute, Inc., Massachusetts Institute of Technology, and Regents of the University of California). The correlation between C3AR1 expression and the immune-infiltrating cells as well as the correlation analysis between C3AR1 expression and the corresponding immune-marker sets were conducted using the TIMER and GEPIA databases.

Results

The expression of C3AR1 was significantly (P<0.001) differentially expressed on several tumor types, while its prognosis value could only be determined on STAD, with a high expression of C3AR1 closely correlated with a poor prognosis. The GSEA analysis revealed that the differential expression of C3AR1 profoundly affected the immune-related biological processes. The expression of C3AR1 was strongly and positively correlated with the infiltration of monocytes, tumor-associated macrophages, M2 macrophages, dendritic cells, and exhausted T cells.

Conclusions

Our results have revealed that a high expression of C3AR1 is positively correlated with a poor prognosis and increased tumor-immune infiltration. C3AR1 can promote the polarization of M2 macrophages and T cell exhaustion, leading to the immune escape of STAD. These findings suggest that C3AR1 could be used as a prognostic and immune-infiltration marker in the pathogenesis of STAD.

Exosome-mediated delivery of functionally active miRNA-375-3p mimic regulate epithelial mesenchymal transition (EMT) of colon cancer cells

AIMS

EMT is the process by which a polarized epithelial cell undergoes several changes leading to highly invasive and fibroblast-like morphology. It has been described that miR-375 is inversely associated with EMT in cancerous patients and can effectively inhibit invasion and migration of tumor cells. Here, we investigate whether miR-375 mimic delivered by tumor-derived exosomes could reverse EMT process.

MAIN METHODS

The exosomes were isolated from HT-29 and SW480. Subsequently, exosomes were loaded with miR-375-3p mimic applying modified calcium chloride method. Quantitative real-time PCR was used for evaluation of the loading efficiency of miR-375 mimic in the exosomes. The effects of miR-375 loaded tumor exosomes (TEXomiR) on EMT process investigated using flow cytometry, cell morphology, and invasion and migration assay.

KEY FINDINGS

The in vitro results showed that the tumor derived exosomes can efficiently deliver miR-375 mimic to reduce the expression of β-catenin, vimentin, ZEB1, and snail. In contrast, TEXomiR significantly increased the expression of E- cadherin in EMT process. Furthermore, the migration and invasion abilities of HT-29 and SW480 cells were inhibited by TEXomiR. The expression of CD44 and CD133 are increased in EMT process. Flow cytometry evaluation demonstrated that treatment with TEXomiR significantly decreased the expression of CD44 and CD133 in SW480 cell line.

SIGNIFICANCE

Our results imply that colon cancer cells-derived exosomes could be used as an effective nonvehicle to deliver miR-375-3p mimic. Moreover, TEXomiR may be a potent therapeutic agent for the treatment of metastatic colorectal cancer.

Targeting transforming growth factor-β signaling for enhanced cancer chemotherapy

During the past decades, drugs targeting transforming growth factor-β (TGFβ) signaling have received tremendous attention for late-stage cancer treatment since TGFβ signaling has been recognized as a prime driver for tumor progression and metastasis. Nonetheless, in healthy and pre-malignant tissues, TGFβ functions as a potent tumor suppressor. Furthermore, TGFβ signaling plays a key role in normal development and homeostasis by regulating cell proliferation, differentiation, migration, apoptosis, and immune evasion, and by suppressing tumor-associated inflammation. Therefore, targeting TGFβ signaling for cancer therapy is challenging. Recently, we and others showed that blocking TGFβ signaling increased chemotherapy efficacy, particularly for nanomedicines. In this review, we briefly introduce the TGFβ signaling pathway, and the multifaceted functions of TGFβ signaling in cancer, including regulating the tumor microenvironment (TME) and the behavior of cancer cells. We also summarize TGFβ targeting agents. Then, we highlight TGFβ inhibition strategies to restore the extracellular matrix (ECM), regulate the tumor vasculature, reverse epithelial-mesenchymal transition (EMT), and impair the stemness of cancer stem-like cells (CSCs) to enhance cancer chemotherapy efficacy. Finally, the current challenges and future opportunities in targeting TGFβ signaling for cancer therapy are discussed.

Fibroblast growth factor 2 accelerates the epithelial-mesenchymal transition in keratinocytes during wound healing process

In the wound healing process, the morphology of keratinocytes at the wound edge temporarily changes to a spindle morphology, which is thought to occur due to an epithelial–mesenchymal transition (EMT). Fibroblast growth factor (FGF) 2, also called basic FGF, has the potential to accelerate wound closure by activating vascular endothelial cells and fibroblasts. We examined the effects of FGF2 on keratinocyte morphology and EMT in wounded skin. Histological examination of murine wounds treated with FGF2 revealed that wound edge keratinocytes formed thickened and multilayered epithelia. In addition, we detected wound edge keratinocytes migrating individually toward the wound center. These migrating keratinocytes exhibited not only spindle morphology but also down-regulated E-cadherin and up-regulated vimentin expression, which is characteristic of EMT. In FGF2-treated wounds, a PCR array revealed the upregulation of genes related to EMT, including transforming growth factor (TGF) signaling. Further, FGF2-treated wound edge keratinocytes expressed EMT-associated transcription factors, including Snai2, and showed translocation of β-catenin from the cell membrane to the cytoplasm/nucleus. However, in vitro examination of keratinocytes revealed that FGF2 alone did not activate EMT in keratinocytes, but that FGF2 might promote EMT in combination with TGFβ1. These findings suggest that FGF2 treatment of wounds could promote keratinocyte EMT, accelerating wound closure.

Biochemical activity of magnesium ions on human osteoblast migration

Magnesium is well known as a biodegradable biomaterial that has been reported to promote bone remodeling in several studies; however, the underlying biological mechanism remains unclear. In the present study, the role of magnesium ions in the migration of U-2 OS cells, which are osteoblast-like cell lines, was investigated. Magnesium treatment did not significantly alter the global transcriptome of U-2 OS cells, but increased the protein expression level of SNAI2, an epithelial-mesenchymal transition (EMT) marker. In addition, it was confirmed that the junctional site localization of Zona-occludens 1 (ZO-1), a representative tight junction protein, was destroyed by magnesium treatment; furthermore, it was determined that cytoplasmic localization increased, and alkaline phosphatase (ALP) activity increased. The obtained results on the mechanism by which magnesium is involved in osteoblast migration, which is important for fracture healing, will contribute to the understanding of the bone-formation process in patients with osteoporosis and musculoskeletal injury.

Microenvironmental Hypoxia Induces Dynamic Changes in Lung Cancer Synthesis and Secretion of Extracellular Vesicles

Extracellular vesicles (EVs) mediate critical intercellular communication within healthy tissues, but are also exploited by tumour cells to promote angiogenesis, metastasis, and host immunosuppression under hypoxic stress. We hypothesize that hypoxic tumours synthesize hypoxia-sensitive proteins for packing into EVs to modulate their microenvironment for cancer progression. In the current report, we employed a heavy isotope pulse/trace quantitative proteomic approach to study hypoxia sensitive proteins in tumour-derived EVs protein. The results revealed that hypoxia stimulated cells to synthesize EVs proteins involved in enhancing tumour cell proliferation (NRSN2, WISP2, SPRX1, LCK), metastasis (GOLM1, STC1, MGAT5B), stemness (STC1, TMEM59), angiogenesis (ANGPTL4), and suppressing host immunity (CD70). In addition, functional clustering analyses revealed that tumour hypoxia was strongly associated with rapid synthesis and EV loading of lysosome-related hydrolases and membrane-trafficking proteins to enhance EVs secretion. Moreover, lung cancer-derived EVs were also enriched in signalling molecules capable of inducing epithelial-mesenchymal transition in recipient cancer cells to promote their migration and invasion. Together, these data indicate that lung-cancer-derived EVs can act as paracrine/autocrine mediators of tumorigenesis and metastasis in hypoxic microenvironments. Tumour EVs may, therefore, offer novel opportunities for useful biomarkers discovery and therapeutic targeting of different cancer types and at different stages according to microenvironmental conditions.

True significance of N-acetylglucosaminyltransferases GnT-III, V and α1,6 fucosyltransferase in epithelial-mesenchymal transition and cancer

It is well known that numerous cancer-related changes occur in glycans that are attached to glycoproteins, glycolipids and proteoglycans on the cell surface and these changes in structure and the expression of the glycans are largely regulated by glycosyl-transferases, glycosidases, nucleotide sugars and their related genes. Such structural changes in glycans on cell surface proteins may accelerate the progression, invasion and metastasis of cancer cells. Among the over 200 known glycosyltransferases and related genes, β 1,6 N-acetylglucosaminyltransferase V (GnT-V) (the MGAT5 gene) and α 1,6 fucosyltransferase (FUT8) (the FUT8 gene) are representative enzymes in this respect because changes in glycans caused by these genes appear to be related to cancer metastasis and invasion in vitro as well as in vivo, and a number of reports on these genes in related to epithelial-mesenchymal transition (EMT) have also appeared. Another enzyme, one of the N-glycan branching enzymes, β1,4 N-acetylglucosaminyltransferase III (GnT-III) (the MGAT3 gene) has been reported to suppress EMT. However, there are intermediate states between EMT and mesenchymal-epithelial transition (MET) and some of these genes have been implicated in both EMT and MET and are also probably in an intermediate state. Therefore, it would be difficult to clearly define which specific glycosyltransferase is involved in EMT or MET or an intermediate state. The significance of EMT and N-glycan branching glycosyltransferases needs to be reconsidered and the inhibition of their corresponding genes would also be desirable in therapeutics. This review mainly focuses on GnT-III, GnT-V and FUT8, major players as N-glycan branching enzymes in cancer in relation to EMT programs, and also discusses the catalytic mechanisms of GnT-V and FUT8 whose crystal structures have now been obtained.

Tumor microenvironment and epithelial mesenchymal transition as targets to overcome tumor multidrug resistance

It is well established that multifactorial drug resistance hinders successful cancer treatment. Tumor cell interactions with the tumor microenvironment (TME) are crucial in epithelial-mesenchymal transition (EMT) and multidrug resistance (MDR). TME-induced factors secreted by cancer cells and cancer-associated fibroblasts (CAFs) create an inflammatory microenvironment by recruiting immune cells. CD11b+/Gr-1+ myeloid-derived suppressor cells (MDSCs) and inflammatory tumor associated macrophages (TAMs) are main immune cell types which further enhance chronic inflammation. Chronic inflammation nurtures tumor-initiating/cancer stem-like cells (CSCs), induces both EMT and MDR leading to tumor relapses. Pro-thrombotic microenvironment created by inflammatory cytokines and chemokines from TAMs, MDSCs and CAFs is also involved in EMT and MDR. MDSCs are the most common mediators of immunosuppression and are also involved in resistance to targeted therapies, e.g. BRAF inhibitors and oncolytic viruses-based therapies. Expansion of both cancer and stroma cells causes hypoxia by hypoxia-inducible transcription factors (e.g. HIF-1α) resulting in drug resistance. TME factors induce the expression of transcriptional EMT factors, MDR and metabolic adaptation of cancer cells. Promoters of several ATP-binding cassette (ABC) transporter genes contain binding sites for canonical EMT transcription factors, e.g. ZEB, TWIST and SNAIL. Changes in glycolysis, oxidative phosphorylation and autophagy during EMT also promote MDR. Conclusively, EMT signaling simultaneously increases MDR. Owing to the multifactorial nature of MDR, targeting one mechanism seems to be non-sufficient to overcome resistance. Targeting inflammatory processes by immune modulatory compounds such as mTOR inhibitors, demethylating agents, low-dosed histone deacetylase inhibitors may decrease MDR. Targeting EMT and metabolic adaptation by small molecular inhibitors might also reverse MDR. In this review, we summarize evidence for TME components as causative factors of EMT and anticancer drug resistance.

Epithelial-Mesenchymal Transition in Endometriosis-When Does It Happen?

Epithelial-mesenchymal transition (EMT) is an important process of cell remodeling characterized by the gradual loss of the epithelial phenotype and progressive gain of a mesenchymal phenotype. EMT is not an all-or-nothing process, but instead a transition of epithelial to mesenchymal cells with intermediate cell states. Recently, EMT was described in endometriosis, and many EMT-specific pathways like Twist, Snail, Slug, Zinc finger E-box-binding homeobox 1/2 (ZEB1/2), E/N-cadherin, keratins, and claudins are involved. However, as pointed out in this review, a comparison of the eutopic endometrium of women with and without endometriosis yielded only subtle changes of these EMT markers. Furthermore, only very few alterations in cell-cell contacts could be found but without changes in the epithelial phenotype. This suggests only a partial EMT which is not a prerequisite for the detachment of endometrial cells and, thus, not critical for the first step(s) in the pathogenesis of endometriosis. In contrast, the majority of changes in the EMT-related marker expression were found in the ectopic endometrium, especially in the three endometriotic entities, ovarian, peritoneal, and deep infiltrating endometriosis (DIE), compared with the eutopic endometrium. In this review, we examine the most important EMT pathways described in endometriosis and propose that partial EMT might result from the interaction of endometrial implants with their surrounding microenvironment.

S100A4/non-muscle myosin II signaling regulates epithelial-mesenchymal transition and stemness in uterine carcinosarcoma

Uterine carcinosarcoma (UCS) represents a true example of cancer associated with epithelial-mesenchymal transition (EMT), which exhibits cancer stem cell (CSC)-like traits. Although S100A4 is an inducer of EMT, little is known about its involvement in UCS tumorigenesis. Herein, we focused on the functional role of S100A4 during development of UCS. Expression of S100A4 and molecules associated with its function were also examined in 35 UCS cases. In endometrial carcinoma cell lines, S100A4 promoter activity and mRNA levels were significantly increased by the transfection of NF-κB/p65, independent of a putative κB-binding site in the promoter. Cells stably overexpressing S100A4 showed enhancement of CSC properties, along with decreased cell proliferation and acceleration of cell migration. These phenotypes were abrogated in S100A4-knockdown cells. A combination of S100A4 antibody-mediated co-immunoprecipitation and shotgun proteomics analysis revealed that S100A4 strongly interacted with non-muscle myosin II (NMII) heavy chains, including myosin 9 and myosin 14. Specific inhibition of NMII by blebbistatin phenocopied S100A4 overexpression and induced a fibroblast-like morphology. In clinical samples, S100A4 score was significantly higher in sarcomatous as compared with carcinomatous components of UCS, and was positively correlated with ALDH1, Slug, and vimentin scores, and inversely with Ki-67 labeling indices. These findings suggest that an S100A4/NMII-related signaling cascade may contribute to the establishment and maintenance of EMT/CSC properties, along with changes in cell proliferation and migration capability. These events may be initiated in carcinomatous components in UCS and lead to divergent sarcomatous differentiation.