Regulation Of Epithelial-mesenchymal Transition Research Articles

Role of exosomal miRNAs and macrophage polarization in gastric cancer: a novel therapeutic strategy.

Gastric cancer (GC) is one of the most common gastrointestinal cancers worldwide, with consistently high morbidity and mortality rates and poor prognosis. Most patients are diagnosed at an advanced stage due to the lack of specific presentation in the early stages. Exosomes are a class of extracellular vesicles (EVs) widely found in body fluids and can release genetic material or multiple proteins to facilitate intercellular communication. In recent years, exosomal miRNAs have gained attention for their role in various cancers. These exosomal miRNAs can impact GC development and progression by targeting specific genes or influencing signaling pathways and cytokines involved in Angiogenesis, epithelial-mesenchymal transition (EMT), drug resistance, and immune regulation. They show great potential in terms of diagnosis, prognosis, and treatment of GC. Notably, the gastrointestinal tract has the largest number of macrophages, which play a significant role in GC progression. Tumor-associated macrophages (TAMs) are the most abundant immune cells in the tumor microenvironment (TME) and can influence macrophage programming through various mediators, including macrophage polarization. Macrophage polarization is involved in inflammatory responses and significantly impacts the GC process.

Doxazosin Attenuates Development of Testosterone Propionate-induced Prostate Growth by regulating TGF-β/Smad Signaling Pathway, Prostate-specific Antigen Expression and Reversing Epithelial-mesenchymal Transition in Mice and Stroma Cells.

Finasteride and doxazosin are used for the treatment of benign prostatic hyperplasia (BPH) and lower urinary tract symptoms (LUTS). Epithelial-mesenchymal transition (EMT) plays an important role in BPH, little is known about the growth inhibition and anti-fibrosis effects of doxazosin on the regulation of EMT and morphology in the prostate. The present study examined the effects of doxazosin on testosterone propionate (TP)-induced prostate growth in vivo and in vitro and its impact on the EMT and TGF-β/Smad signaling pathway. Doxazosin (5 or 10 mg/kg) and finasteride (10 mg/kg) were administered orally for 28 days in TP-induced mice. The prostate index (prostate/body weight ratio), morphological characteristics and the protein expression of the prostate were examined. We further examined the effects of doxazosin and finasteride on the EMT and TGF-β/Smad signaling pathway in mice and in human prostate stroma cell (WPMY-1). The prostate wet weight, prostate index decreased after treatment. Doxazosin (5 or 10 mg/kg), finasteride (10 mg/kg) or a combination (doxazosin + finasteride) were shown to reverse the pathological and morphological characteristics of the prostate. Doxazosin and finasteride inhibited TP-induced prostate growth, EMT, and the TGF-β/Smad signaling pathway by downregulating the expression of TGF-β1, TGFBR2, p-Smad2/3, N-cadherin, vimentin, fibronectin and α-SMA, whereas expression of E-cadherin was increased after treatment with either doxazosin or finasteride. Doxazosin (1-50 μM) inhibited normal human prostate stroma cell growth (WPMY-1) after 48 h with or without testosterone treatment. Doxazosin also regulated the EMT and proteins related to the TGF-β/Smad signaling pathway in WPMY-1 cells after 24 h. Additionally, doxazosin decreased protein expression of the prostate specific antigen both in vivo and in vitro. This study demonstrated that doxazosin inhibits prostate growth by regulating the EMT and TGF-β/Smad signaling pathways in the prostate This finding suggests that doxazosin has potential as a new signaling pathway for the treatment of BPH.

A hybrid epithelial-mesenchymal transition program enables basal epithelial cells to bypass stress-induced stasis and contributes to a metaplastic breast cancer progenitor state

BackgroundHuman mammary epithelial cell (HMEC) cultures encounter a stress-associated barrier termed stasis, during which most cells adopt a senescence-like phenotype. From these cultures, rare variants emerge from the basal epithelial population, re-initiating growth. Variants exhibit pre-malignant properties, including an aberrant epigenetic program that enables continued proliferation and acquisition of genetic changes. Following oncogenic transformation, variants produce tumors that recapitulate the histopathological characteristics of metaplastic breast cancer (MBC), a rare and aggressive subtype marked by the differentiation of neoplastic epithelium into squamous and mesenchymal elements.MethodsUsing a serum-free HMEC culture system, we probed the capacity for phenotypic plasticity inherent to basal epithelial cell populations from human breast tissue as they navigated stasis and emerged as variant populations.ResultsWe observed robust activation of a TGF-β-dependent epithelial-mesenchymal transition (EMT) program in basal epithelial cells during stasis, followed by subsequent attenuation of this program in emerging variants. Inhibition of the TGF-β pathway or depleting the EMT regulators Snail or Slug allowed basal epithelial cells to collectively bypass stasis, demonstrating that cellular dysfunction and arrest resulting from TGF-β and EMT activation are central to this in vitro barrier. The spontaneous emergence of variants from stasis cultures was associated with a restricted EMT trajectory, characterized by the stabilization of hybrid EMT states associated with greater proliferative capacity, rather than progressing to a complete mesenchymal state characterized by irreversible growth arrest. Epigenetic mechanisms, which contributed to the dysregulated growth control characteristic of the variant phenotype, also contributed to the stability of the hybrid EMT program in variants. By overcoming the cellular dysfunction and growth arrest resulting from TGF-β and complete EMT, variants exhibited a higher oncogenic transformation efficiency compared to pre-stasis basal epithelial cells. Inhibiting the TGF-β pathway prior to stasis significantly reduced EMT in the basal epithelial population, alleviated selective pressure driving variant emergence, and also enhanced oncogenic transformation efficiency, resulting in tumors with markedly diminished metaplastic differentiation.ConclusionsThis study reveals how an epigenetic program governs basal epithelial cell fate decisions and contributes to the development of MBC progenitors by restricting access to terminal mesenchymal states that induce growth arrest and, instead, favoring hybrid EMT states with enhanced tumorigenic potential.

The Multifaceted Role of Striatin-interacting Protein 2 (STRIP2) in Disease Pathogenesis and Cancer Progression.

Striatin-interacting protein 2 (STRIP2), encoded by the STRIP2 gene, plays a critical role in various biological processes. It is an integral part of the striatin-interacting phosphatase and kinase (STRIPAK) complex and is involved in cell growth, proliferation, migration, and differentiation. In this review, we explored the multifaceted functions of STRIP2 across different cancers, including non-small cell lung cancer (NSCLC), breast cancer, colorectal cancer, prostate cancer, and others. We searched the PubMed database for studies investigating STRIP2 in tumors or pathological processes. Our search yielded 30 studies. After meticulous screening, only 14 studies were included in this review. Based on our results, STRIP2 is overexpressed and amplified in multiple cancer types, including NSCLC, breast cancer, colorectal cancer, and prostate cancer, and is associated with poor prognosis. In NSCLC, it promotes tumor progression through mechanisms involving mRNA stabilization, Akt/mTOR pathway, epithelial-mesenchymal transition (EMT), and immune regulation. In breast and colorectal cancers, elevated STRIP2 levels correlate with reduced overall survival. In prostate cancer, STRIP2 contributes to cell migration and cytoskeletal organization. Furthermore, interaction of STRIP2 with immune checkpoint genes suggests its role in tumor immune evasion, offering therapeutic potential for targeting the tumor microenvironment. We conclude that STRIP2 acts as an oncogene in various tumors and is associated with a poor prognosis. It is involved in critical oncogenic pathways including proliferation, EMT, and immune regulation, highlighting its potential as a therapeutic target. This review supports the importance of investigating the diagnostic, prognostic, and therapeutic role of STRIP2 in various cancers, particularly NSCLC.

The transcription factor CREB regulates epithelial-mesenchymal transition of lens epithelial cells by phosphorylation-dependent and phosphorylation-independent mechanisms.

Epithelial mesenchymal transition (EMT) of lens epithelial cells (LECs) is one of the most important pathogenic mechanisms in lens fibrotic disorders, and the regulatory mechanisms of EMT have not been fully understood. Here, we demonstrate that the cAMP-response element binding protein (CREB) can regulate lens EMT in a phosphorylation-dependent and phosphorylation-independent manners with dual mechanisms. First, CREB-S133 phosphorylation is implicated in TGFβ-induced EMT of mouse LECs and also in injury-induced mouse anterior subcapsular cataract model. The interaction between CREB and p300 is necessary for CREB regulation of TGFβ-induced EMT, since inhibition of CREB-p300 interaction and p300 knockdown led to attenuated expression of mesenchymal genes. Second, S133A-CREB, a mutant mimicking constant dephosphorylation at S133, exhibits notable occupancy in the enhancers of mesenchymal genes and confers robust transcription activity on EMT genes. Introduction of R314A mutation in S133A-CREB, which abolishes the interaction between S133A-CREB and its co-activator, cAMP-regulated transcriptional co-activators led to substantial suppression of mesenchymal gene expression in mouse LECs. Taken together, our results showed that CREB regulates lens EMT in dual mechanisms and that the S133A-CREB acts as a novel transcription factor. Mechanistically, CREB interacts with p300 in a S133 phosphorylation-dependent manner to positively regulate lens EMT genes. In contrast, S133A-CREB interacts with cAMP-regulated transcriptional co-activators to confer a robust activation of lens EMT genes.

A study of the role of androgen receptor and androgen receptor variant 7 in TNBC patients and the effect of their targeting by Enzalutamide and EPI-001 in MDA-MB-231

The lack of targeted therapy for triple-negative breast cancer (TNBC) is among the mainsprings of its poor prognosis. This study aimed to elucidate the role of the androgen receptor (AR) and its splice variant 7 (ARv7) in TNBC patients. Further, the molecular impact of their blockers, Enzalutamide and EPI-001, on the TNBC cell line MDA-MB-231 was investigated. Thereby, immunohistochemical expression of AR/ARv7 was assessed for TNBC Egyptian patients. Moreover, bioinformatics analysis of AR/ARv7 RNA status was carried out on TNBC patients from The Cancer Genome Atlas Breast Carcinoma project (TCGA-BRCA). Data from both groups was correlated with patients’ clinicopathological features. Besides, scratch wound healing assay and ELISA were employed to assess the effect of AR/ARv7 blockers on several metastasis markers in MDA-MB-231 cell line. In the Egyptian-TNBC patients, AR expression was associated with worse 7-year DFS (40.6 ± 18.6 %). In addition, ARv7 showed cytoplasmic and nuclear patterns, and both cytoplasmic and nuclear ARv7+ patients demonstrated a worse 7-year DFS (22.7 ± 17.7 % and 20 ± 17.9 %) and overall survival (63.6 ± 14.5 % and 40 ± 21.8 %). Importantly, 80 % of the nuclear ARv7+ patients developed distant metastasis. The data of the TCGA-TNBC patients showed a tendency for poor outcomes in the high ARv7-expressing patients. Molecularly, in MDA-MB-231, both inhibitors modulated metastasis and epithelial to mesenchymal transition (EMT) markers ROCK1, ROCK2, c-Myc, E-cadherin and N-cadherin, with EPI-001 downregulating NF-ĸB level as well. We concluded that ARv7 indicated poor prognosis in the studied cohorts and that blocking of AR/ARv7 abated metastasis and key regulators of EMT in MDA-MB-231, at least in part by targeting ROCK/NF-ĸB/c-Myc axis.

N-acetylglucosaminyltransferase V drives colorectal cancer metastasis by facilitating ZO-1 ubiquitination and degradation

Increasing evidence supports the crucial role of Epithelial-Mesenchymal Transition (EMT) in cancer invasion and metastasis. N-acetylglucosaminyltransferase V (MGAT5), which is associated with multiantenna glycosylation, can contribute to tumorigenesis, yet its specific role in promoting colorectal cancer (CRC) metastasis remains unclear. Bioinformatics analysis of CRC datasets revealed that elevated MGAT5 expression was associated with EMT and a poor prognosis. In vitro experiments confirmed the pivotal role of MGAT5 as an EMT regulator in CRC cells. MGAT5 overexpression stimulated cell proliferation and migration, while MGAT5 knockdown had the opposite effect. Mechanistically, MGAT5 promoted EMT through multiantenna glycosylation of ZO-1, promoting its ubiquitination and reducing its expression. Clinically, MGAT5 upregulation in the CRC TMA correlated negatively with ZO-1 expression, which is indicative of malignancy and a poor prognosis. This study revealed that MGAT5 promotes EMT in CRC via interactions between multiple antenna glycosylation products and ZO-1 ubiquitination/degradation, indicating that MGAT5 could serve as a promising therapeutic target for CRC.Graphical

Elevated expression levels of the protein kinase DYRK1B induce mesenchymal features in A549 lung cancer cells

BackgroundThe protein kinase DYRK1B is a negative regulator of cell proliferation but has been found to be overexpressed in diverse human solid cancers. While DYRK1B is recognized to promote cell survival and adaption to stressful conditions, the consequences of elevated DYRK1B levels in cancer cells are largely uncharted.MethodsTo elucidate the role of DYRK1B in cancer cells, we established a A549 lung adenocarcinoma cell model featuring conditional overexpression of DYRK1B. This system was used to characterize the impact of heightened DYRK1B levels on gene expression and to monitor phenotypic and functional changes.ResultsA549 cells with induced overexpression of wild type DYRK1B acquired a mesenchymal cell morphology with diminished cell-cell contacts and a reorganization of the pericellular actin cytoskeleton into stress fibers. This transition was not observed in cells overexpressing a catalytically impaired DYRK1B variant. The phenotypic changes were associated with increased expression of the transcription factors SNAIL and SLUG, which are core regulators of epithelial mesenchymal transition (EMT). Further profiling of DYRK1B-overexpressing cells revealed transcriptional changes that are characteristic for the mesenchymal conversion of epithelial cells, including the upregulation of genes that are related to cancer cell invasion and metastasis. Functionally, DYRK1B overexpression enhanced the migratory capacity of A549 cells in a wound healing assay.ConclusionsThe present data identify DYRK1B as a regulator of phenotypic plasticity in A549 cells. Increased expression of DYRK1B induces mesenchymal traits in A549 lung adenocarcinoma cells.

Lipidomic profiling of triple-negative breast cancer cells reveals distinct metabolic signatures associated with EpCAM expression

Lipid metabolism is essential at all stages of cancer progression, particularly for triple-negative breast cancer (TNBC) the deadliest cancer subtype for women patients. TNBC cells exhibit significant metabolic heterogeneity, which contributes to their aggressive behavior. Epithelial-to-mesenchymal transition (EMT), a key step in metastasis, is associated with distinct lipid profiles, where the epithelial cell adhesion molecule (EpCAM) was found to be decreased along the transition. To understand this link, we employed lipidomic profiling of the TNBC cell line SUM149PT, which exhibits high variability in EpCAM, an epithelial marker. Using EpCAM levels to categorize cells with high and low EpCAM expression using fluorescence-activated cell sorter, we performed targeted mass spectrometry analysis of various lipid classes (glycerophospholipids, glycerolipids, lysophospholipids, and sphingolipids) by a hydrophilic interaction liquid chromatography-tandem mass spectrometry (HILIC-MS/MS)-based screening method. After correcting for cell size, we identified a unique lipid profile associated with each EpCAM expression level. Notably, cells with higher EpCAM expression displayed lower levels of lysophosphatidylethanolamine (LPE). This finding suggests a potential role for LPE in the regulation of EMT in TNBC.

A spotlight on the role of copper in the epithelial to mesenchymal transition.

The complex process known as epithelial to mesenchymal transition (EMT) plays a fundamental role in several biological settings, encompassing embryonic development, wound healing, and pathological conditions such as cancer and fibrosis. In recent years, a bulk of research has brought to light the key role of copper, a trace element with essential functions in cellular metabolism, cancer initiation and progression. Indeed, copper, besides functioning as cofactor of enzymes required for essential cellular processes, such as energy production and oxidation reactions, has emerged as an allosteric regulator of kinases whose activity is required to fulfill cancer dissemination through the EMT. In this comprehensive review, we try to describe the intricate relationship between the transition metal copper and EMT, spanning from the earliest foundational studies to the latest advancements. Our aim is to shed light on the multifaceted roles undertaken by copper in EMT in cancer and to unveil the diverse mechanisms by which copper homeostasis exerts its influence over EMT regulators, signaling pathways, cell metabolic reprogramming and transcription factors ultimately contributing to the spread of cancer. Therefore, this review not only may contribute to a deeper comprehension of copper-mediated mechanisms in EMT but also supports the hypothesis that targeting copper may contribute to counteract the progression of EMT-associated pathologies.

Multi-omics analysis reveals BZW1's regulation of EMT via the Wnt pathway in lung adenocarcinoma.

Exploring the role of novel cancer gene BZW1 in lung adenocarcinoma (LUAD) and unveiling associated signalling pathways. Firstly, we conducted a pan-cancer analysis of BZW1 using multiple databases. Subsequently, leveraging single-cell data from LUAD, we successfully uncovered potential oncological processes associated with BZW1 and further validated them through experimentation. Simultaneously, we continued to investigate the potential molecular mechanisms underlying the oncological processes mediated by BZW1. Additionally, we employed various machine learning algorithms to construct prognostic models concerning BZW1 and the epithelial-mesenchymal transition (EMT) process. Our research firstly demonstrated the elevated expression of BZW1 in various cancer cells. Leveraging single-cell data from LUAD, we identified that BZW1 regulates the occurrence of EMT in LUAD, a phenomenon validated across multiple LUAD cell lines. Moreover, we further discovered that BZW1 regulates LUAD's EMT process through the Wnt/β-catenin signalling pathway. Lastly, we successfully constructed prognostic models using BZW1-related genes and EMT genes.

Integrated transcriptomic analysis reveals dysregulated immune infiltration and pro-inflammatory cytokines in the secretory endometrium of recurrent implantation failure patients

Abstract Recurrent implantation failure (RIF) is a leading impediment to assisted reproductive technology, yet the underlying pathogenesis of RIF remains elusive. Recent studies have sought to uncover novel biomarkers and etiological factors of RIF by profiling transcriptomes of endometrial samples. Nonetheless, the inherent heterogeneity among published studies and a scarcity of experimental validations hinder the identification of robust markers of RIF. Hence, we integrated six publicly accessible datasets with 209 samples, including microarray profiles of endometrial samples in the secretory phase. After removing batch effects, we identified 175 differentially expressed genes. Gene set enrichment analysis identified dysregulation of immunological pathways in RIF. We also observed altered immune infiltration and pro-inflammatory cytokines in RIF. Protein–protein interaction network analysis identified ten hub genes, representing two co-expression modules significantly related to RIF. Knockdown of ENTPD3, one of the hub genes, promoted the epithelial-mesenchymal transition process and resulted in elevated levels of pro-inflammatory cytokines. Collectively, our study reveals abnormal gene expressions involving the regulation of epithelial-mesenchymal transition and immune status in RIF, providing valuable insights into its pathogenesis.

GAMG ameliorates silica-induced pulmonary inflammation and fibrosis via the regulation of EMT and NLRP3/TGF-β1/Smad signaling pathway

Silicosis is an occupational disease caused by exposure to silica characterized by pulmonary inflammation and fibrosis, for which there is a lack of effective drugs. Glycyrrhetinic acid 3-O-β-D-glucuronide (GAMG) can treat silicosis due to its anti-inflammatory and anti-fibrotic properties. Here, the effect of therapeutic interventions of GAMG was evaluated in early-stage and advanced silicosis mouse models. GAMG significantly improved fibrotic pathological changes and collagen deposition in the lungs, alleviated lung inflammation in the BALF, reduced the expression of TNF-α, IL-6, NLRP3, TGF-β1, vimentin, Col-Ⅰ, N-cadherin, and inhibited epithelial-mesenchymal transition (EMT), thereby ameliorating pulmonary fibrosis. Moreover, the dose of 100 mg/kg GAMG can effectively prevent early-stage silicosis, while that of 200 mg/kg was recommended for advanced silicosis. In vitro and in vivo study verified that GAMG can suppress EMT through the NLRP3/TGF-β1/Smad2/3 signaling pathway. Therefore, GAMG could be a promising preventive (early-stage silicosis) and therapeutic (advanced silicosis) strategy, which provides a new idea for formulating prevention and treatment strategies.

An adaptive Epithelial-Mesenchymal Transition Program Enables Basal Epithelial Cells to Bypass Stress-Induced Stasis and Contributes to Metaplastic Breast Cancer Progenitor State.

Human mammary epithelial cell (HMEC) cultures encounter a stress-associated barrier termed stasis, during which most cells adopt a senescence-like phenotype. From these cultures, rare variants emerge from the basal epithelial population, re-initiating growth. Variants exhibit pre-malignant properties, including an aberrant epigenetic program that enables continued proliferation and acquisition of genetic changes. Following oncogenic transformation, variants produce tumors that recapitulate the histopathological characteristics of metaplastic breast cancer (MBC), a rare subtype characterized by squamous and mesenchymal differentiation. Using the conventional serum-free HMEC culture system, we probed the capacity for phenotypic plasticity inherent to basal epithelial cell populations from human breast tissue as they navigated stasis and emerged as variant populations. We observed robust activation of a TGF-β-dependent epithelial-mesenchymal transition (EMT) program in basal epithelial cells during stasis, followed by subsequent attenuation of this program in emerging variants. Inhibiting the TGF-β pathway or depleting the EMT regulators Snail or Slug allowed basal epithelial cells to collectively bypass stasis, demonstrating that cellular dysfunction and arrest resulting from TGF-β and EMT activation are central to this in vitro barrier. The spontaneous emergence of variants from stasis cultures was associated with a restricted EMT trajectory, which diverted cells away from a complete mesenchymal state characterized by irreversible growth arrest, and instead limited variants to epithelial and intermediate EMT states associated with greater proliferative capacity and stemness. Epigenetic mechanisms, which contributed to the dysregulated growth control characteristic of the variant phenotype, also contributed to the constrained EMT program in variants. By overcoming the cellular dysfunction and growth arrest resulting from TGF-β and EMT activation, variants exhibited increased oncogenic transformation efficiency compared to pre-stasis basal epithelial cells. Inhibiting the TGF-β pathway prior to stasis significantly reduced EMT in the basal epithelial population, alleviated selective pressure driving variant emergence, and enhanced oncogenic transformation efficiency, resulting in tumors with markedly diminished metaplastic differentiation. This study reveals how adaptive EMT reprogramming governs basal epithelial cell fate decisions and contributes to the development of MBC progenitors by restricting access to terminal mesenchymal states that induce growth arrest and, instead, favoring intermediate states with enhanced tumorigenic potential.

Nuclear receptor TLX functions to promote cancer stemness and EMT in prostate cancer via its direct transactivation of CD44 and stem cell-regulatory transcription factors.

Prostate cancer stem cells (PCSCs) play crucial roles in therapy-resistance and metastasis in castration-resistant prostate cancer (CRPC). Certain functional link between cancer stemness and epithelial-mesenchymal transition (EMT) is involved in CRPC. However, up-stream regulators controlling these two processes in PCSCs are still poorly understood. Recently, we have shown that orphan nuclear receptor TLX can promote tumour initiation and progression in CRPC by repressing androgen receptor and oncogene-induced senescence. PCSCs were isolated from various prostate cancer cell lines and clinical tumour tissues using multiple methods for various in vitro and in vivo oncogenic growth analyses. Direct targets of TLX involved in stemness and EMT regulation were determined by specific reporter gene assays and ligand-driven modulation of TLX activity. PCSCs isolated from various sources exhibited increased expression of TLX. Functional and molecular characterisation showed that TLX could function to promote cancer stemness and EMT in prostate cancer cells via its direct transactivation of CD44, SOX2, POU5F1 and NANOG, which share certain functional crosstalk in these two cellular processes. TLX could act as a key up-stream regulator in transcriptional control of stemness and EMT in PCSCs, which contribute to their tumorigenicity, castration-resistance and metastasis potentials in advanced prostate cancer.

Putative epithelial-mesenchymal transitions during salamander limb regeneration: Current perspectives and future investigations.

Previous studies have implicated epithelial-mesenchymal transition (EMT) in salamander limb regeneration. In this review, we describe putative roles for EMT during each stage of limb regeneration in axolotls and other salamanders. We hypothesize that EMT and EMT-like gene expression programs may regulate three main cellular processes during limb regeneration: (1) keratinocyte migration during wound closure; (2) transient invasion of the stump by epithelial cells undergoing EMT; and (3) use of EMT-like programs by non-epithelial blastemal progenitor cells to escape the confines of their niches. Finally, we propose nontraditional roles for EMT during limb regeneration that warrant further investigation, including alternative EMT regulators, stem cell activation, and fibrosis induced by aberrant EMT.

Characteristics and transcriptional regulators of spontaneous epithelial–mesenchymal transition in genetically unperturbed patient-derived non-spindled breast carcinoma

BackgroundAlthough tumor cells undergoing epithelial–mesenchymal transition (EMT) typically exhibit spindle morphology in experimental models, such histomorphological evidence of EMT has predominantly been observed in rare primary spindle carcinomas. The characteristics and transcriptional regulators of spontaneous EMT in genetically unperturbed non-spindled carcinomas remain underexplored.MethodsWe used primary culture combined with RNA sequencing (RNA-seq), single-cell RNA-seq (scRNA-seq), and in situ RNA-seq to explore the characteristics and transcription factors (TFs) associated with potential spontaneous EMT in non-spindled breast carcinoma.ResultsOur primary culture revealed carcinoma cells expressing diverse epithelial–mesenchymal traits, consistent with epithelial–mesenchymal plasticity. Importantly, carcinoma cells undergoing spontaneous EMT did not necessarily exhibit spindle morphology, even when undergoing complete EMT. EMT was a favored process, whereas mesenchymal–epithelial transition appeared to be crucial for secondary tumor growth. Through scRNA-seq, we identified TFs that were sequentially and significantly upregulated as carcinoma cells progressed through the EMT process, which correlated with increasing VIM expression. Once upregulated, the TFs remained active throughout the EMT process. ZEB1 was a key initiator and sustainer of EMT, as indicated by its earliest significant upregulation in the EMT process, its exact correlation with VIM expression, and the reversal of EMT and downregulation of EMT-upregulated TFs upon ZEB1 knockdown. The correlation between ZEB1 and vimentin expression in triple-negative breast cancer and metaplastic breast carcinoma tumor cohorts further highlighted its role. The immediate upregulation of ZEB2 following that of ZEB1, along with the observation that the knockdown of ZEB1 or ZEB2 downregulates both ZEB1 and ZEB2 concomitant with the reversal of EMT, suggests their functional cooperation in EMT. This finding, together with that of a lack of correlation of SNAI1, SNAI2, and TWIST1 expression with the mesenchymal phenotype, indicated EMT-TFs have a context-dependent role in EMT. Upregulation of EMT-related gene signatures during EMT correlated with poor patient outcomes, highlighting the biological importance of the model. Elevated EMT gene signatures and increased ZEB1 and ZEB2 expression in vimentin-positive compared to vimentin-negative carcinoma cells within the corresponding primary tumor tissue confirmed ZEB1 and ZEB2 as intrinsic, instead of microenvironmentally-induced, EMT regulators, and vimentin as an in vivo indicator of EMT.ConclusionsOur findings provide insights into the characteristics and transcriptional regulators of spontaneous EMT in primary non-spindled carcinoma.

Emerging biological functions of Twist1 in cell differentiation.

Twist1 is required for embryonic development and expresses after birth in mesenchymal stem cells derived from mesoderm, where it governs mesenchymal cell development. As a well-known regulator of epithelial-mesenchymal transition or embryonic organogenesis, Twist1 is important in a variety of developmental systems, including mesoderm formation, neurogenesis, myogenesis, cranial neural crest cell migration, and differentiation. In this review, we first highlight the physiological significance of Twist1 in cell differentiation, including osteogenic, chondrogenic, and myogenic differentiation, and then detail its probable molecular processes and signaling pathways. On this premise, we summarize the significance of Twist1 in distinct developmental disorders and diseases to provide a reference for studies on cell differentiation/development-related diseases.

Pan-Cancer Screening and Validation of CALU's Role in EMT Regulation and Tumor Microenvironment in Triple-Negative Breast Cancer.

Cancer-associated fibroblasts (CAFs) significantly contribute to tumor progression and the development of resistance to therapies across a range of malignancies, notably breast cancer. This study aims to elucidate the specific role and prognostic relevance of CALU across multiple cancer types. The association between CALU expression and prognosis, along with clinical characteristics in BRCA, HNSC, KIRP, LGG, and LIHC, was analyzed using data from the TCGA, GTEx, and GEO databases. Transcriptomic analysis of TCGA BRCA project data provided insights into the interaction between CALU and epithelial-mesenchymal transition (EMT) marker genes. Using TIMER and TISCH databases, the correlation between CALU expression and tumor microenvironment infiltration was assessed, alongside an evaluation of CALU expression across various cell types. Furthermore, CALU's influence on TNBC BRCA cell lines was explored, and its expression in tumor tissues was confirmed through immunohistochemical analysis of clinical samples. This study revealed a consistent upregulation of CALU across several tumor types, including BRCA, KIRP, LIHC, HNSC, and LGG, with elevated CALU expression being associated with unfavorable prognoses. CALU expression was particularly enhanced in clinical contexts linked to poor outcomes. Genomic analysis identified copy number alterations as the principal factor driving CALU overexpression. Additionally, a positive correlation between CALU expression and CAF infiltration was observed, along with its involvement in the EMT process in both CAFs and malignant cells. In vitro experiments demonstrated that CALU is highly expressed in TNBC-BRCA cell lines, and knockdown of CALU effectively reversed EMT progression and inhibited cellular migration. Immunohistochemical analysis of clinical samples corroborated the elevated expression of CALU in tumors, along with alterations in EMT markers. This comprehensive pan-cancer analysis underscores CALU's critical role in modulating the tumor microenvironment and facilitating cell migration via the EMT pathway, identifying it as a potential therapeutic target.

Cell Polarity-related Gene PTK7, a Potential Diagnostic Biomarker in Pan-cancer.

PTK7 (Protein Tyrosine Kinase 7), a member of the receptor protein tyrosine kinase family, was originally discovered in colon cancer cells. It plays a pivotal role in numerous developmental and physiological processes, particularly in the regulation of cell polarity. Despite accumulating evidence of PTK7's significant influence on tumor development, a comprehensive pan-cancer analysis of PTK7 has yet to be conducted. We conducted a comprehensive analysis of PTK7's expression, prognostic value, and mutational patterns across various tumor types. We further explored the correlations between PTK7 expression and tumor stemness, immune-related genes, immune scores, and immune cell infiltration. Enrichment analysis revealed PTK7's critical involvement in pan-cancer functions and processes, including the WNT pathway, Epithelial-Mesenchymal Transition (EMT), and cell polarity regulation. Additionally, we validated PTK7's expression in gastric cancer via immunohistochemistry. Our study indicates that PTK7 holds promise as an ideal pan-cancer biomarker due to its involvement in tumor progression and tumor immunity.