Role of CD44 expressed in renal tubules during maladaptive repair in renal fibrogenesis in an allopurinol-induced rat model of chronic kidney disease.

The kidney is a major target organ for the adverse effects of pharmaceuticals; renal tubular epithelial cells (TECs) are particularly vulnerable to drug-induced toxicity. TECs have regenerative capacity; however, maladaptive repair of TECs after injury leads to renal fibrosis, resulting in chronic kidney disease (CKD). We previously reported the specific expression of CD44 in failed-repair TECs of rat CKD model induced by ischemia reperfusion injury. Here, we investigated the pathophysiological role of CD44 in renal fibrogenesis in allopurinol-treated rat CKD model. Dilated or atrophic TECs expressing CD44 in fibrotic areas were collected by laser microdissection and subjected to microarray analysis. Gene ontology showed that extracellular matrix (ECM)-related genes were upregulated and differentiation-related genes were downregulated in dilated/atrophic TECs. Ingenuity Pathway Analysis identified CD44 as an upstream regulator of fibrosis-related genes, including Fn1, which encodes fibronectin. Immunohistochemistry demonstrated that dilated/atrophic TECs expressing CD44 showed decreases in differentiation markers of TECs and clear expression of mesenchymal markers during basement membrane attachment. In situ hybridization revealed an increase in Fn1 mRNA in the cytoplasm of dilated/atrophic TECs, whereas fibronectin was localized in the stroma around these TECs, supporting the production/secretion of ECM by dilated/atrophic TECs. Overall, these data indicated that dilated/atrophic TECs underwent a partial epithelial-mesenchymal transition (pEMT) and that CD44 promoted renal fibrogenesis via induction of ECM production in failed-repair TECs exhibiting pEMT. CD44 was detected in the urine and serum of APL-treated rats, which may reflect the expression of CD44 in the kidney.

CD44 expression in renal tubular epithelial cells in the kidneys of rats with cyclosporine-induced chronic kidney disease.

Renal tubular epithelial cell (TEC) injury is the most common cause of drug-induced kidney injury (DIKI). Although TEC regeneration facilitates renal function and structural recovery following DIKI, maladaptive repair of TECs leads to irreversible fibrosis, resulting in chronic kidney disease (CKD). CD44 is specifically expressed in TECs during maladaptive repair in several types of rat CKD models. In this study, we investigated CD44 expression and its role in renal fibrogenesis in a cyclosporine (CyA) rat model of CKD. Seven-week-old male Sprague-Dawley rats fed a low-salt diet were subcutaneously administered CyA (0, 15, or 30 mg/kg) for 28 days. CD44 was expressed in atrophic, dilated, and hypertrophic TECs in the fibrotic lesions of the CyA groups. These TECs were collected by laser microdissection and evaluated by microarray analysis. Gene ontology analysis suggested that these TECs have a mesenchymal phenotype, and pathway analysis identified CD44 as an upstream regulator of fibrosis-related genes, including fibronectin 1 (Fn1). Immunohistochemistry revealed that epithelial and mesenchymal markers of TECs of fibrotic lesions were downregulated and upregulated, respectively, and that these TECs were surrounded by a thickened basement membrane. In situ hybridization revealed an increase in Fn1 mRNA in the cytoplasm of TECs of fibrotic lesions, whereas fibronectin protein was localized in the stroma surrounding these tubules. Enzyme-linked immunosorbent assay revealed increased serum CD44 levels in CyA-treated rats. Collectively, these findings suggest that CD44 contributes to renal fibrosis by inducing fibronectin secretion in TECs exhibiting partial epithelial-mesenchymal transition and highlight the potential of CD44 as a biomarker of renal fibrosis.

Single-cell transcriptomic analysis of gingivo-buccal oral cancer reveals two dominant cellular programs.

Oral squamous cell carcinoma of the gingivo-buccal region (OSCC-GB) is the most common cancer among men in India, and is associated with poor prognosis and frequent recurrence. Cellular heterogeneity in OSCC-GB was investigated by single-cell RNA sequencing of tumors derived from the oral cavity of 12 OSCC-GB patients, 3 of whom had concomitant presence of a precancerous lesion (oral submucous fibrosis [OSMF]). Unique malignant cell types, features, and phenotypic shifts in the stromal cell population were identified in oral tumors with associated submucous fibrosis. Expression levels of FOS, ATP1A, and DUSP1 provided robust discrimination between tumors with or without the concomitant presence of OSMF. Malignant cell populations shared between tumors with and without OSMF were enriched with the expression of partial epithelial-mesenchymal transition (pEMT) or fetal cell type signatures indicative of two dominant cellular programs in OSCC-GB-pEMT and fetal cellular reprogramming. Malignant cells exhibiting fetal cellular and pEMT programs were enriched with the expression of immune-related pathway genes known to be involved in antitumor immune response. In the tumor microenvironment, higher infiltration of immune cells than the stromal cells was observed. The T cell population was large in tumors and diverse subtypes of T cells with varying levels of infiltration were found. We also detected double-negative PLCG2+ T cells and cells with intermediate M1-M2 macrophage polarization. Our findings shed light on unique aspects of cellular heterogeneity and cell states in OSCC-GB.

Ubiquitin-specific protease 11 promotes partial epithelial-to-mesenchymal transition by deubiquitinating the epidermal growth factor receptor during kidney fibrosis.

The aberrant expression of ubiquitin-specific protease 11 (USP11) is believed to be related to tumor progression. However, few studies have reported the biological function and clinical importance of USP11 in kidney fibrosis. Here, we demonstrated USP11 was highly upregulated in the kidneys from patients with chronic kidney disease and correlated positively with fibrotic lesion but negatively with kidney function. Conditional USP11 deletion or pharmacologic inhibition with Mitoxantrone attenuated pathological lesions and improved kidney function in both hyperuricemic nephropathy (HN)- and folic acid (FA)-induced mouse models of kidney fibrosis. Mechanistically, by RNA sequencing, USP11 was found to be involved in nuclear gene transcription of the epidermal growth factor receptor (EGFR). USP11 co-immunoprecipitated and co-stained with extra-nuclear EGFR and deubiquitinated and protected EGFR from proteasome-dependent degradation. Genetic or pharmacological depletion of USP11 facilitated EGFR degradation and abated augmentation of TGF-ß1 and downstream signaling. This consequently alleviated the partial epithelial-mesenchymal transition, G2/M arrest and aberrant secretome of profibrogenic and proinflammatory factors in uric acid-stimulated tubular epithelial cells. Moreover, USP11 deletion had anti-fibrotic and anti-inflammatory kidney effects in the murine HN and FA models. Thus, our study provides evidence supporting USP11 as a promising target for minimizing kidney fibrosis and that inhibition of USP11 has potential to be an effective strategy for patients with chronic kidney disease.

Tumour budding and poorly differentiated clusters in colon cancer - different manifestations of partial epithelial-mesenchymal transition.

Morphological features including infiltrative growth, tumour budding (TB), and poorly differentiated clusters (PDCs) have a firmly established negative predictive value in colorectal cancer (CRC). Despite extensive research, the mechanisms underlying different tumour growth patterns remain poorly understood. The aim of this study was to investigate the involvement of epithelial-mesenchymal transition (EMT) in TB and PDCs in CRC. Using laser-capture microdissection, we obtained distinct parts of the primary CRC including TB, PDCs, expansive tumour front, and the central part of the tumour, and analysed the expression of EMT-related markers, i.e. the miR-200 family, ZEB1/2, RND3, and CDH1. In TB, the miR-200 family and CDH1 were significantly downregulated, while ZEB2 was significantly upregulated. In PDCs, miR-141, miR-200c, and CDH1 were significantly downregulated. No significant differences were observed in the expression of any EMT-related markers between the expansive tumour front and the central part of the tumour. Our results suggest that both TB and PDCs are related to partial EMT. Discrete differences in morphology and expression of EMT-related markers between TB and PDCs indicate that they represent different manifestations of partial EMT. TB seems to be closer to complete EMT than PDCs. © 2022 The Authors. The Journal of Pathology published by John Wiley & Sons Ltd on behalf of The Pathological Society of Great Britain and Ireland.

SNAI2 promotes the malignant transformation of oral leukoplakia by modulating p-EMT.

OBJECTIVE: Snail family transcriptional repressor 2 (SNAI2) is a key regulator of partial epithelial-mesenchymal transition (p-EMT) and is associated with tumorigenesis. Whether SNAI2 promotes oral leukoplakia (OLK) malignant transformation by modulating p-EMT is unclear. MATERIALS AND METHODS: This study utilized two clinical datasets (GSE26549 and GSE85195) from the Gene Expression Omnibus database, cytological experiments, and a 4-nitroquinoline 1-oxide-induced mice model to explore the role of SNAI2 in OLK malignant transformation. RESULTS: The clinical cohort found SNAI2, as a risk factor (HR = 2.50, 95% CI: 1.08-5.79, p = 0.033), could promote OLK malignant transformation (p = 0.012). Cytological experiments indicated that SNAI2 overexpression promoted DOK cell proliferation, invasion, migration, and increase the protein expression of p-EMT relative signatures, whereas SNAI2 silencing has opposite effects. Furthermore, the mice model and clinical datasets demonstrated the expression of SNAI2 and p-EMT relative signatures were increased with OLK malignant transformation. And SNAI2 was strongly correlated with p-EMT. Besides, co-expressed genes of SNAI2 were also enriched in p-EMT relative biological processes and signaling pathways. CONCLUSIONS: p-EMT plays a significant role in promoting the OLK malignant transformation. As an important regulator of p-EMT, SNAI2 could be a target to block the OLK malignant transformation.

Comprehensive Integrated Single-Cell Whole Transcriptome Analysis Revealed the p-EMT Tumor Cells-CAFs Communication in Oral Squamous Cell Carcinoma.

Cancer-associated fibroblasts (CAFs) and partial epithelial-mesenchymal transition (p-EMT) tumor cells are closed together and contribute to the tumor progression of oral squamous cell carcinoma (OSCC). In the present study, we deeply analyzed and integrated OSCC single-cell RNA sequencing datasets to define OSCC CAFs and p-EMT subpopulations. We highlighted the cell-cell interaction network of CAFs and p-EMT tumor cells and suggested biomarkers for the diagnosis and prognosis of OSCC during the metastasis condition. The analysis discovered four subtypes of CAFs: one p-EMT tumor cell population, and cycling tumor cells as well as TNFSF12-TNFRSF25/TNFRSF12A interactions between CAFs and p-EMT tumor cells during tumor metastasis. This suggests the prediction of therapeutically targetable checkpoint receptor-ligand interactions between CAFs and p-EMT tumor cells in OSCC regarding the metastasis status.

Comprehensive analysis of partial epithelial mesenchymal transition-related genes in hepatocellular carcinoma.

Increasing evidence has revealed that cancer cells undergoing an intermediate state, partial epithelial mesenchymal transition (p-EMT), tend to metastasize rather than complete EMT. We performed a comprehensive analysis of E-cadherin and 25 p-EMT-related genes in HCC to explore the roles and regulatory mechanisms of them in HCC. We analysed E-cadherin and 25 p-EMT-related genes in HCC and constructed an mRNA-miRNA-lncRNA ceRNA subnetwork containing p-EMT-related genes by bioinformatic approaches. IHC was used to identify the protein expression of key p-EMT-related genes, P4HA2, ITGA5, MMP9, MT1X and SPP1. Complete EMT is not necessary for HCC progression. Overexpression of P4HA2, ITGA5, MMP9, SPP1 and down-regulation of MT1X were found in HCC tissues, which were significantly associated with poor prognosis of HCC patients. By means of stepwise reverse prediction and validation from mRNA to lncRNA, an mRNA-miRNA-lncRNA ceRNA subnetwork correlated with HCC prognosis was identified by expression and survival analysis. This study implied that key p-EMT-related genes P4HA2, ITGA5, MMP9, MT1X, SPP1 could be prognostic biomarkers and potential targets of therapy for HCC patients. We constructed an mRNA-miRNA-lncRNA subnetwork containing p-EMT-related genes successfully, among which each component might be utilized as a prognostic biomarker of HCC.

Epithelial cell adhesion molecule promotes breast cancer resistance protein-mediated multidrug resistance in breast cancer by inducing partial epithelial-mesenchymal transition.

Overexpression of breast cancer resistance protein (BCRP) plays a crucial role in the acquired multidrug resistance (MDR) in breast cancer. The elucidation of molecular events that confer BCRP-mediated MDR is of major therapeutic importance in breast cancer. Epithelial cell adhesion molecule (EpCAM) has been implicated in tumor progression and drug resistance in various types of cancers, including breast cancer. However, the role of EpCAM in BCRP-mediated MDR in breast cancer remains unknown. In the present study, we revealed that EpCAM expression was upregulated in BCRP-overexpressing breast cancer MCF-7/MX cells, and EpCAM knockdown using siRNA reduced BCRP expression and increased the sensitivity of MCF-7/MX cells to mitoxantrone (MX). The epithelial-mesenchymal transition (EMT) promoted BCRP-mediated MDR in breast cancer cells, and EpCAM knockdown partially suppressed EMT progression in MCF-7/MX cells. In addition, Wnt/ß-catenin signaling was activated in MCF-7/MX cells, and the inhibition of this signaling attenuated EpCAM and BCRP expression and partially reversed EMT. Together, this study illustrates that EpCAM upregulation by Wnt/ß-catenin signaling induces partial EMT to promote BCRP-mediated MDR resistance in breast cancer cells. EpCAM may be a potential therapeutic target for overcoming BCRP-mediated resistance in human breast cancer.

Osteopontin-driven partial epithelial-mesenchymal transition governs the development of middle ear cholesteatoma.

Cholesteatoma is a common disease of the middle ear. Currently, surgical removal is the only treatment option and patients face a high risk of relapse. The molecular basis of cholesteatoma remains largely unknown. Here, we show that Osteopontin (OPN), a predominantly secreted protein, plays a crucial role in the development of middle ear cholesteatoma. Global transcriptome analysis revealed the loss of epithelial features and an enhanced immune response in human cholesteatoma tissues. Quantitative RT-PCR and immunohistochemical staining of middle ear cholesteatoma validated the reduced expression of epithelial markers, as well as the elevated expression of mesenchymal markers including Vimentin and Fibronectin, but not N-Cadherin, α-smooth muscle actin (α-SMA) or ferroptosis suppressor protein 1 (FSP1), indicating a partial epithelial-mesenchymal transition (EMT) state. Besides, the expression of OPN was significantly elevated in human cholesteatoma tissues. Treatment with OPN promoted cell proliferation, survival and migration and led to a partial EMT in immortalized human keratinocyte cells. Importantly, blockade of OPN signaling could remarkably improve the cholesteatoma-like symptoms in SD rats. Our mechanistic study demonstrated that the AKT-zinc finger E-box binding homeobox 2 (ZEB2) axis mediated the effects of OPN. Overall, these findings suggest that targeting the OPN signaling represents a promising strategy for the treatment of middle ear cholesteatoma.

Fasudil attenuates oxidative stress-induced partial epithelial-mesenchymal transition of tubular epithelial cells in hyperuricemic nephropathy via activating Nrf2.

Anti-partial epithelial-mesenchymal transition (pEMT) treatment of renal tubular epithelial cells (TECs) represents a promising therapeutic approach. Hyperuricemia nephropathy (HN) arises as a consequence of hyperuricemia (HUA)-induced tubulointerstitial fibrosis (TIF). Studies have suggested that the Ras homolog member A (RhoA)/Rho-associated kinase (ROCK) pathway is a crucial signaling transduction system in renal fibrosis. Fasudil, a RhoA/ROCK inhibitor, has exhibited the potential to prevent fibrosis progress. However, its impact on the pEMT of TECs in HN remains unclear. Here, an HN rat model and an uric acid (UA)-stimulated human kidney 2 (HK2) cell model were established and treated with Fasudil to explore its effects. Furthermore, the underlying mechanism of action involved in the attenuation of pEMT in TECs by Fasudil during HN was probed by using multiple molecular approaches. The HN rat model exhibited significant renal dysfunction and histopathological damage, whereas in vitro and in vivo experiments further confirmed the pEMT status accompanied by RhoA/ROCK pathway activation and oxidative stress in tubular cells exposed to UA. Notably, Fasudil ameliorated these pathological changes, and this was consistent with the trend of ROCK silencing in vitro. Mechanistically, we identified the Neh2 domain of nuclear factor erythroid 2-related factor 2 (Nrf2) as a target of Fasudil for the first time. Fasudil targets Nrf2 activation and antagonizes oxidative stress to attenuate the pEMT of TECs in HN. Our findings suggest that Fasudil attenuates oxidative stress-induced pEMT of TECs in HN by targeting Nrf2 activation. Thus, Fasudil is a potential therapeutic agent for the treatment of HN.

Early growth response protein 2 promotes partial epithelial-mesenchymal transition by phosphorylating Smad3 during renal fibrosis.

Chronic kidney disease (CKD) is a serious health problem worldwide, which ultimately leads to end-stage renal disease (ESRD). Renal fibrosis is the common pathway and major pathological manifestation for various CKD proceeding to ESRD. However, the underlying mechanisms and effective therapies are still ambiguous. Early growth response 2 (EGR2) is reportedly involved in organ formation and cell differentiation. To determine the role of EGR2 in renal fibrosis, we respectively confirmed the increased expression of EGR2 in kidney specimens from both CKD patients and mice with location in proximal tubules. Genetic deletion of EGR2 attenuated obstructive nephropathy while EGR2 overexpression further promoted renal fibrosis in mice subjected to unilateral ureteral obstruction (UUO) due to extracellular matrix (ECM) deposition mediating by partial epithelial-mesenchymal transition (EMT) as well as imbalance between matrix metalloproteinases (MMPs) and tissue inhibitor of MMPs (TIMPs). We found that EGR2 played a critical role in Smad3 phosphorylation, and inhibition of EGR2 reduced partial EMT leading to blockade of ECM accumulation in cultured human kidney 2 cells (HK2) treated with transforming growth factor ß1 (TGF-ß1). In addition, the transcription co-stimulator signal transducer and activator of transcription 3 (STAT3) phosphorylation was confirmed to regulate the transcription level of EGR2 in TGF-ß1-induced HK2 cells. In conclusion, this study demonstrated that EGR2 played a pathogenic role in renal fibrosis by a p-STAT3-EGR2-p-Smad3 axis. Thus, targeting EGR2 could be a promising strategy for CKD treatment.

TGF-ß downstream of Smad3 and MAPK signaling antagonistically regulate the viability and partial epithelial-mesenchymal transition of liver progenitor cells.

BACKGROUND: Liver progenitor cells (LPCs) are a subpopulation of cells that contribute to liver regeneration, fibrosis and liver cancer initiation under different circumstances. RESULTS: By performing adenoviral-mediated transfection, CCK-8 analyses, F-actin staining, transwell analyses, luciferase reporter analyses and Western blotting, we observed that TGF-ß promoted cytostasis and partial epithelial-mesenchymal transition (EMT) in LPCs. In addition, we confirmed that TGF-ß activated the Smad and MAPK pathways, including the Erk, JNK and p38 MAPK signaling pathways, and revealed that TGFß-Smad signaling induced growth inhibition and partial EMT, whereas TGFß-MAPK signaling had the opposite effects on LPCs. We further found that the activity of Smad and MAPK signaling downstream of TGF-ß was mutually restricted in LPCs. Mechanistically, we found that TGF-ß activated Smad signaling through serine phosphorylation of both the C-terminal and linker regions of Smad2 and 3 in LPCs. Additionally, TGFß-MAPK signaling inhibited the phosphorylation of Smad3 but not Smad2 at the C-terminus, and it reinforced the linker phosphorylation of Smad3 at T179 and S213. We then found that overexpression of mutated Smad3 at linker phosphorylation sites intensifies TGF-ß-induced cytostasis and EMT, mimicking the effects of MAPK inhibition in LPCs, whereas mutation of Smad3 at the C-terminus caused LPCs to blunt TGF-ß-induced cytostasis and partial EMT. CONCLUSION: These results suggested that TGF-ß downstream of Smad3 and MAPK signaling were mutually antagonistic in regulating the viability and partial EMT of LPCs. This antagonism may help LPCs overcome the cytostatic effect of TGF-ß under fibrotic conditions and maintain partial EMT and progenitor phenotypes.

Feline SCCs of the Head and Neck Display Partial Epithelial-Mesenchymal Transition and Harbor Stem Cell-like Cancer Cells.

Squamous cell carcinoma of the head and neck (HNSCC) is a malignant cancer disease in humans and animals. There is ample evidence that the high plasticity of cancer cells, i.e., their ability to switch from an epithelial to a mesenchymal, endothelial, and stem cell-like phenotype, chiefly contributes to progression, metastasis, and multidrug resistance of human HNSCCs. In feline HNSCC, the field of cancer cell plasticity is still unexplored. In this study, fourteen feline HNSCCs with a known feline papillomavirus (FPV) infection status were subjected to histopathological grading and subsequent screening for expression of epithelial, mesenchymal, and stem cell markers by immunohistochemistry (IHC) and immunofluorescence staining (IF). Irrespective of the FPV infection status, all tumors except one corresponded to high-grade, invasive lesions and concurrently expressed epithelial (keratins, E-cadherin, ß-catenin) and mesenchymal (vimentin, N-cadherin, CD146) proteins. This finding is indicative for partial epithelial-mesenchymal transition (pEMT) events in the lesions, as similarly described for human HNSCCs. IF double staining revealed the presence of CD44/CD271 double-positive cells notably within the tumors' invasive fronts that likely correspond to cancer stem cells. Taken together, the obtained findings suggest that feline HNSCCs closely resemble their human counterparts with respect to tumor cell plasticity.

p38 Mitogen-Activated Protein Kinase Inhibition of Mesenchymal Transdifferentiated Tumor Cells in Head and Neck Squamous Cell Carcinoma.

High mortality in head and neck squamous cell carcinoma (HNSCC) is due to recurrence, metastasis, and radiochemotherapy (RCT) resistance. These phenomena are related to the tumor cell subpopulation undergoing partial epithelial to mesenchymal transition (pEMT). Repeated transforming growth factor-beta (TGF-beta-1) treatment via the p38 mitogen-activated protein kinase (p38 MAPK) signaling pathway induces pEMT in SCC-25 HNSCC cells, and activates and stabilizes the pro-EMT transcription factor Slug. We investigated the growth inhibitory, cisplatin-sensitizing, and pro-apoptotic effects of p38 MAPK inhibition in cisplatin-resistant (SCC-25) and -sensitive (UPCI-SCC090) HNSCC cell lines, using two specific p38 MAPK inhibitors, SB202190 and ralimetinib. Cell viability was measured by MTT assay; cell cycle distribution and cell death were evaluated by flow cytometry; p38 MAPK phosphorylation, Slug protein stabilization, and p38 MAPK downstream targets were investigated by Western blot. p-p38 inhibitors achieved sustained phosphorylation of p38 MAPK (Thr180/Tyr182) and inhibition of its function, which resulted in decreased phosphorylation (Thr69/71) of the downstream target pATF2 in pEMT cells. Subsequently, the p-p38 inhibition resulted in reduced Slug protein levels. In accordance, p-p38 inhibition led to sensitization of pEMT cells to cisplatin-induced cell death; moreover, p-p38 inhibitor treatment cycles significantly decreased the viability of cisplatin-surviving cells. In conclusion, clinically relevant p38 inhibitors might be effective for RCT-resistant pEMT cells in HNSCC patients.

Relationship between Tumor Budding and Partial Epithelial-Mesenchymal Transition in Head and Neck Cancer.

Tumor budding (TB), a microscopic finding in the stroma ahead of the invasive fronts of tumors, has been well investigated and reported as a prognostic marker in head and neck squamous cell carcinoma (HNSCC). Epithelial-mesenchymal transition (EMT) is a crucial step in tumor progression and metastasis, and its status cannot be distinguished from TB. The current understanding of partial EMT (p-EMT), the so-called halfway step of EMT, focuses on the tumor microenvironment (TME). Although this evidence has been investigated, the clinicopathological and biological relationship between TB and p-EMT remains debatable. At the invasion front, previous research suggested that cancer-associated fibroblasts (CAFs) are important for tumor progression, metastasis, p-EMT, and TB formation in the TME. Although there is biological evidence of TB drivers, no report has focused on their organized functional relationships. Understanding the mechanism of TB onset and the relationship between p-EMTs may facilitate the development of novel diagnostic and prognostic methods, and targeted therapies for the prevention of metastasis in epithelial cancer. Thus far, major pieces of evidence have been established from colorectal cancer (CRC), due to a large number of patients with the disease. Herein, we review the current understanding of p-EMT and TME dynamics and discuss the relationship between TB development and p-EMT, focusing on CAFs, hypoxia, tumor-associated macrophages, laminin-integrin crosstalk, membrane stiffness, enzymes, and viral infections in cancers, and clarify the gap of evidence between HNSCC and CRC.

Snail-mediated partial epithelial mesenchymal transition augments the differentiation of local lung myofibroblast.

The pathogenesis of pulmonary fibrosis diseases is considered to be related with environmental exposures, but the exact mechanism is unclear and there are no effective treatments. The contribution of epithelial-mesenchymal transition (EMT) to lung fibrosis has been controversial. It was found that partial EMT might play a vital role in renal fibrosis. We also found that partial EMT might be involved in fibrosis diseases. In this study, we used a silicosis animal model of pulmonary fibrosis to observe whether partial EMT existed in pulmonary fibrosis disease and a co-culture system culturing fibroblasts and alveolar epithelial cells stimulated by TGF-ß1 to evaluate the probable effects of partial EMT, thus determined the probable role of partial EMT in pulmonary fibrosis diseases. In vivo, the results revealed that partial EMT might exist in silica-induced lung fibrosis model and Snail which is a potent EMT inducer was involved during the process. In vitro, a co-culture system was used to evaluate the effects of EMT in murine alveolar epithelial type II (ATII) cells on the activation of underlying murine lung fibroblasts into myofibroblasts. The results showed that epithelial cells undergoing EMT promoted the differentiation of lung myofibroblast and this epithelial-mesenchymal crosstalk was mainly controlled by Snail. Following Snail silencing the EMT and the activation of NIH-3T3 into myofibroblast were obviously inhibited. It indicated that targeting this novel Snail might be a viable strategy for the treatment of lung fibrosis diseases.

Identification of Prognostic Biomarkers Originating From the Tumor Stroma of Betel Quid-Associated Oral Cancer Tissues.

BACKGROUND: Partial epithelial-mesenchymal transition (p-EMT) is a distinct clinicopathological feature prevalent in oral cavity tumors of The Cancer Genome Atlas. Located at the invasion front, p-EMT cells require additional support from the tumor stroma for collective cell migration, including track clearing, extracellular matrix remodeling and immune evasion. The pathological roles of otherwise nonmalignant cancer-associated fibroblasts (CAFs) in cancer progression are emerging. METHODS: Gene set enrichment analysis was used to reveal differentially enriched genes and molecular pathways in OC3 and TW2.6 xenograft tissues, representing mesenchymal and p-EMT tumors, respectively. R packages of genomic data science were executed for statistical evaluations and data visualization. Immunohistochemistry and Alcian blue staining were conducted to validate the bioinformatic results. Univariate and multivariate Cox proportional hazards models were performed to identify covariates significantly associated with overall survival in clinical datasets. Kaplan-Meier curves of estimated overall survival were compared for statistical difference using the log-rank test. RESULTS: Compared to mesenchymal OC3 cells, tumor stroma derived from p-EMT TW2.6 cells was significantly enriched in microvessel density, tumor-excluded macrophages, inflammatory CAFs, and extracellular hyaluronan deposition. By translating these results to clinical transcriptomic datasets of oral cancer specimens, including the Puram single-cell RNA-seq cohort comprising ~6000 cells, we identified the expression of stromal TGFBI and HYAL1 as independent poor and protective biomarkers, respectively, for 40 Taiwanese oral cancer tissues that were all derived from betel quid users. In The Cancer Genome Atlas, TGFBI was a poor marker not only for head and neck cancer but also for additional six cancer types and HYAL1 was a good indicator for four tumor cohorts, suggesting common stromal effects existing in different cancer types. CONCLUSIONS: As the tumor stroma coevolves with cancer progression, the cellular origins of molecular markers identified from conventional whole tissue mRNA-based analyses should be cautiously interpreted. By incorporating disease-matched xenograft tissue and single-cell RNA-seq results, we suggested that TGFBI and HYAL1, primarily expressed by stromal CAFs and endothelial cells, respectively, could serve as robust prognostic biomarkers for oral cancer control.

New Insights Into the Role and Mechanism of Partial Epithelial-Mesenchymal Transition in Kidney Fibrosis.

Epithelial-mesenchymal transition (EMT) is described as the process in which injured renal tubular epithelial cells undergo a phenotype change, acquiring mesenchymal characteristics and morphing into fibroblasts. Initially, it was widely thought of as a critical mechanism of fibrogenesis underlying chronic kidney disease. However, evidence that renal tubular epithelial cells can cross the basement membrane and become fibroblasts in the renal interstitium is rare, leading to debate about the existence of EMT. Recent research has demonstrated that after injury, renal tubular epithelial cells acquire mesenchymal characteristics and the ability to produce a variety of profibrotic factors and cytokines, but remain attached to the basement membrane. On this basis, a new concept of "partial epithelial-mesenchymal transition (pEMT)" was proposed to explain the contribution of renal epithelial cells to renal fibrogenesis. In this review, we discuss the concept of pEMT and the most recent findings related to this process, including cell cycle arrest, metabolic alternation of epithelial cells, infiltration of immune cells, epigenetic regulation as well as the novel signaling pathways that mediate this disturbed epithelial-mesenchymal communication. A deeper understanding of the role and the mechanism of pEMT may help in developing novel therapies to prevent and halt fibrosis in kidney disease.

Downregulation of cytokeratin 18 induces cellular partial EMT and stemness through increasing EpCAM expression in breast cancer.

Induction of epithelial-mesenchymal transition (EMT) and cancer stem cell (CSC) characteristics underlie the development of metastasis, chemoresistance, and tumor recurrence in breast cancer. Downregulation of cytokeratin 18 (CK18) is a critical molecular event of EMT; however, its importance in the induction of EMT and CSC features has not been defined to date. This study aimed to investigate the biological significance and underlying molecular mechanisms of CK18 in inducing EMT phenotype and stemness properties of breast cancer cells. Three breast cancer cell lines (i.e., non-metastatic MCF-7, highly metastatic MDA-MB-231, and mitoxantrone (MX)-selected resistant MCF-7/MX cells) and two CK18-knockdown stable cell clones (MCF-7-shCK18-7D and 3C) were used to determine the association between CK18 and EMT and stemness. CK18 expression was extremely low in highly metastatic, resistant, and transforming growth factor (TGF)-ß1/tumor necrosis factor (TNF)-α-treated breast cancer cells with mesenchymal phenotype and increased expression of CSC markers. Depletion of CK18 promoted partial EMT and the acquisition of stemness properties in breast cancer MCF-7 cells. Mechanistically, CK18 interference in MCF-7 cells activated the Wnt/ß-catenin signaling, resulting in the up-regulation of epithelial cell adhesion molecule (EpCAM). Consistently, the stemness properties and metastasis can be attenuated by further knockdown of EpCAM in CK18-depleted cells. In conclusion, downregulation of CK18 promotes partial EMT and enhances breast cancer stemness by increasing EpCAM expression partly via the Wnt/ß-catenin pathway. These findings indicate that CK18 may serve as a potential treatment target for advanced breast cancer.