Revolutionary multi-omics analysis revealing prognostic signature of thyroid cancer and subsequent in vitro validation of SNAI1 in mediating thyroid cancer progression through EMT.

Thyroid carcinoma (TC), the most commonly diagnosed malignancy of the endocrine system, has witnessed a significant rise in incidence over the past few decades. The integration of scRNA-seq with other sequencing approaches offers researchers a distinct perspective to explore mechanisms underlying TC progression. Therefore, it is crucial to develop a prognostic model for TC patients by utilizing a multi-omics approach. We acquired and processed transcriptomic data from the TCGA-THCA dataset, including mRNA expression profiles, lncRNA expression profiles, miRNA expression profiles, methylation chip data, gene mutation data, and clinical data. We constructed a tumor-related risk model using machine learning methods and developed a consensus machine learning-driven signature (CMLS) for accurate and stable prediction of TC patient outcomes. 2 strains of undifferentiated TC cell lines and 1 strain of PTC cell line were utilized for in vitro validation. mRNA, protein levels of hub genes, epithelial-mesenchymal transition (EMT)-associated phenotypes were detected by a series of in vitro experiments. We identified 3 molecular subtypes of TC based on integrated multi-omics clustering algorithms, which were associated with overall survival and displayed distinct molecular features. We developed a CMLS based on 28 hub genes to predict patient outcomes, and demonstrated that CMLS outperformed other prognostic models. TC patients of relatively lower CMLS score had significantly higher levels of T cells, B cells, and macrophages, indicating an immune-activated state. Fibroblasts were predominantly enriched in the high CMLS group, along with markers associated with immune suppression and evasion. We identified several drugs that could be suitable for patients with high CMLS, including Staurosporine_1034, Rapamycin_1084, gemcitabine, and topotecan. SNAI1 was elevated in both undifferentiated TC cell lines, comparing to PTC cells. Knockdown of SNAI1 reduced the cell proliferation and EMT phenotypes of undifferentiated TC cells. Our findings highlight the importance of multi-omics analysis in understanding the molecular subtypes and immune characteristics of TC, and provide a novel prognostic model and potential therapeutic targets for this disease. Moreover, we identified SNAI1 in mediating TC progression through EMT in vitro.

MCTP1 increases the malignancy of androgen-deprived prostate cancer cells by inducing neuroendocrine differentiation and EMT.

Neuroendocrine prostate cancer (PCa) (NEPC), an aggressive subtype that is associated with poor prognosis, may arise after androgen deprivation therapy (ADT). We investigated the molecular mechanisms by which ADT induces neuroendocrine differentiation in advanced PCa. We found that transmembrane protein 1 (MCTP1), which has putative Ca2+ sensing function and multiple Ca2+-binding C2 domains, was abundant in samples from patients with advanced PCa. MCTP1 was associated with the expression of the EMT-associated transcription factors ZBTB46, FOXA2, and HIF1A. The increased abundance of MCTP1 promoted PC3 prostate cancer cell migration and neuroendocrine differentiation and was associated with SNAI1-dependent EMT in C4-2 PCa cells after ADT. ZBTB46 interacted with FOXA2 and HIF1A and increased the abundance of MCTP1 in a hypoxia-dependent manner. MCTP1 stimulated Ca2+ signaling and AKT activation to promote EMT and neuroendocrine differentiation by increasing the SNAI1-dependent expression of EMT and neuroendocrine markers, effects that were blocked by knockdown of MCTP1. These data suggest an oncogenic role for MCTP1 in the maintenance of a rare and aggressive prostate cancer subtype through its response to Ca2+ and suggest its potential as a therapeutic target.

TFAP2A downregulation mediates tumor-suppressive effect of miR-8072 in triple-negative breast cancer via inhibiting SNAI1 transcription.

BACKGROUND: Triple-negative breast cancer (TNBC) represents a highly aggressive subset of breast malignancies characterized by its challenging clinical management and unfavorable prognosis. While TFAP2A, a member of the AP-2 transcription factor family, has been implicated in maintaining the basal phenotype of breast cancer, its precise regulatory role in TNBC remains undefined. METHODS: In vitro assessments of TNBC cell growth and migratory potential were conducted using MTS, colony formation, and EdU assays. Quantitative PCR was employed to analyze mRNA expression levels, while Western blot was utilized to evaluate protein expression and phosphorylation status of AKT and ERK. The post-transcriptional regulation of TFAP2A by miR-8072 and the transcriptional activation of SNAI1 by TFAP2A were investigated through luciferase reporter assays. A xenograft mouse model was employed to assess the in vivo growth capacity of TNBC cells. RESULTS: Selective silencing of TFAP2A significantly impeded the proliferation and migration of TNBC cells, with elevated TFAP2A expression observed in breast cancer tissues. Notably, TNBC patients exhibiting heightened TFAP2A levels experienced abbreviated overall survival. Mechanistically, TFAP2A was identified as a transcriptional activator of SNAI1, a crucial regulator of epithelial-mesenchymal transition (EMT) and cellular proliferation, thereby augmenting the oncogenic properties of TFAP2A in TNBC. Moreover, miR-8072 was unveiled as a negative regulator of TFAP2A, exerting potent inhibitory effects on TNBC cell growth and migration. Importantly, the tumor-suppressive actions mediated by the miR-8072/TFAP2A axis were intricately associated with the attenuation of AKT/ERK signaling cascades and the blockade of EMT processes. CONCLUSIONS: Our findings unravel the role and underlying molecular mechanism of TFAP2A in driving tumorigenesis of TNBC. Targeting the TFAP2A/SNAI1 pathway and utilizing miR-8072 as a suppressor represent promising therapeutic strategies for treating TNBC.

The deubiquitinase USP7 and E3 ligase TRIM21 regulate vasculogenic mimicry and malignant progression of RMS by balancing SNAI2 homeostasis.

BACKGROUND: Rhabdomyosarcoma (RMS) is a rare malignancy and the most common soft tissue sarcoma in children. Vasculogenic mimicry (VM) is a novel tumor microcirculation model different from traditional tumor angiogenesis, which does not rely on endothelial cells to provide sufficient blood supply for tumor growth. In recent years, VM has been confirmed to be closely associated with tumor progression. However, the ability of RMS to form VM has not yet been reported. METHODS: Immunohistochemistry, RT-qPCR and western blot were used to test the expression level of SNAI2 and its clinical significance. The biological function in regulating vasculogenic mimicry and malignant progression of SNAI2 was examined both in vitro and in vivo. Mass spectrometry, co-immunohistochemistry, immunofluorescence staining, and ubiquitin assays were performed to explore the regulatory mechanism of SNAI2. RESULTS: Our study indicated that SNAI2 was abnormally expressed in patients with RMS and RMS cell lines and promoted the proliferation and metastasis of RMS. Through cell tubule formation experiments, nude mice Matrigel plug experiments, and immunohistochemistry (IHC), we confirmed that RMS can form VM and that SNAI2 promotes the formation of VM. Due to SNAI2 is a transcription factor that is not easily drugged, we used Co-IP combined with mass spectrometry to screen for the SNAI2-binding protein USP7 and TRIM21. USP7 depletion inhibited RMS VM formation, proliferation and metastasis by promoting SNAI2 degradation. We further demonstrated that TRIM21 is expressed at low levels in human RMS tissues and inhibits VM in RMS cells. TRIM21 promotes SNAI2 protein degradation through ubiquitination in the RMS. The deubiquitinase USP7 and E3 ligase TRIM21 function in an antagonistic rather than competitive mode and play a key role in controlling the stability of SNAI2 to determine the VM formation and progression of RMS. CONCLUSION: Our findings reveal a previously unknown mechanism by which USP7 and TRIM21 balance the level of SNAI2 ubiquitination, determining RMS vasculogenic mimicry, proliferation, and migration. This new mechanism may provide new targeted therapies to inhibit the development of RMS by restoring TRIM21 expression or inhibiting USP7 expression in RMS patients with high SNAI2 protein levels.

Energy stress-activated AMPK phosphorylates Snail1 and suppresses its stability and oncogenic function.

Triple-negative breast cancer (TNBC) is a highly lethal malignancy with limited therapy options. Aberrant metabolism, a key hallmark of human cancers, plays a crucial role in tumor progression, therapeutic responses and TNBC-related death. However, the underlying mechanisms are not fully understood. In this study, we delineate a previously unrecognized role of aberrant glucose metabolism in regulating the turnover of Snail1, which is a key transcriptional factor of epithelial-mesenchymal transition (EMT) and critically contributes to the acquisition of stemness, metastasis and chemo-resistance. Mechanistically, we demonstrate that AMP-activated protein kinase (AMPK), when activated in response to glucose deprivation, directly phosphorylates Snail1 at Ser11. Such a phosphorylation modification of Snail1 facilitates its recruitment of the E3 ligase FBXO11 and promotes its degradation, thereby suppressing stemness, metastasis and increasing cellular sensitivity to chemotherapies in vitro and in vivo. Clinically, histological analyses reveal a negative correlation between p-AMPKα and Snail1 in TNBC specimens. Taken together, our findings establish a novel mechanism and functional significance of AMPK in linking glucose status to Snail1-dependent malignancies and underscore the potential of AMPK agonists as a promising therapeutic strategy in the management of TNBC.

CSF3 aggravates acute exacerbation of pulmonary fibrosis by disrupting alveolar epithelial barrier integrity.

Idiopathic pulmonary fibrosis (IPF) is a chronic and progressive respiratory disorder characterized by poor prognosis, often presenting with acute exacerbation. The primary cause of death associated with IPF is acute exacerbation of IPF (AE-IPF). However, the pathophysiology of acute exacerbation has not been clearly elucidated yet. This study aims to investigate the underlying pathophysiological molecular mechanism in a mouse AE-PF model. C57BL/6J mice were intratracheally administered bleomycin (BLM, 5 mg/kg) to induce pulmonary fibrosis. After 14 days, lipopolysaccharide (LPS, 2 mg/kg) was injected via the trachea route. Histological assessments, including H&E and Masson staining, as well as inflammatory indicators, were included to evaluate the induction of AE-PF by BLM and LPS in mice. Transcriptomic profiling of pulmonary tissues identified CSF3 as one of the top 10 upregulated DEGs in AE-PF mice. Indeed, administration of exogenous CSF3 protein exacerbated AE-PF in mice. Mechanistically, CSF3 disrupted alveolar epithelial barrier integrity and permeability by regulating specialized cell adhesion complexes such as tight junctions (TJs) and adherens junctions (AJs) via PI3K/p-Akt/Snail pathway, contributing to the aggravation of AE-PF in mice. Moreover, the discovery of elevated sera CSF3 indicated a notable increase in IPF patients during the exacerbation of the disease. Pearson correlation analysis in IPF patients revealed significant positive associations between CSF3 levels and KL-6 levels, LDH levels, CRP levels, respectively. These results provide mechanistic insights into the role of CSF3 in exacerbating of lung fibrotic disease and indicate monitoring CSF3 levels may aid in early clinical decisions for alternative therapy in the management of rapidly progressing IPF.

Low PDE4A expression promoted the progression of ovarian cancer by inducing Snail nuclear translocation.

Widespread metastasis is the primary reason for the high mortality associated with ovarian cancer (OC), and effective targeted therapy for tumor aggressiveness is still insufficient in clinical practice. Therefore, it is urgent to find new targets to improve prognosis of patients. PDE4A is a cyclic nucleotide phosphodiesterase that plays a crucial role in the occurrence and development in various malignancies. Our study firstly reported the function of PDE4A in OC. Expression of PDE4A was validated through bioinformatics analysis, RT-qPCR, Western blot, and immunohistochemistry. Additionally, its impact on cell growth and motility was assessed via in vitro and in vivo experiments. PDE4A was downregulated in OC tissues compared with normal tissues and low PDE4A expression was correlated with poor clinical outcomes in OC patients. The knockdown of PDE4A significantly promoted the proliferation, migration and invasion of OC cells while overexpression of PDE4A resulted in the opposite effect. Furthermore, smaller and fewer tumor metastatic foci were observed in mice bearing PDE4A-overexpressing OVCAR3 cells. Mechanistically, downregulation of PDE4A expression can induce epithelial-mesenchymal transition (EMT) and nuclear translocation of Snail, which suggests that PDE4A plays a pivotal role in suppressing OC progression. Notably, Rolipram, the PDE4 inhibitor, mirrored the effects observed with PDE4A deletion. In summary, the downregulation of PDE4A appears to facilitate OC progression by modulating the Snail/EMT pathway, underscoring the potential of PDE4A as a therapeutic target against ovarian cancer metastasis.

Loss of RAB25 Cooperates with Oncogenes in the Transformation of Human Mammary Epithelial Cells (HMECs) to Give Rise to Claudin-Low Tumors.

The loss of RAB25 expression-RAS superfamily of GTPase characteristic of numerous breast cancers-corresponds with H-RAS point mutations, particularly in triple-negative breast cancers (TNBC), a subtype associated with a poor prognosis. To address the poorly understood factors dictating the progression of TNBC tumors, we examine the cooperative effects that loss of RAB25 expression in human mammary epithelial cell (HMEC) lines with H-RAS mutations confers in tumorigenesis. HMECs were immortalized by transduction with LXSN CDK4 R24C, a mutant form of cyclin-dependent kinase, followed by transduction with hTERT, a catalytic subunit of the telomerase enzyme. We found that with the loss of RAB25 and overexpression of mutant H-RAS61L, immortal HMECs transformed toward anchorage-independent growth and acquired an increased ability to migrate. Furthermore, cells express low CD24, high CD44, and low claudin levels, indicating stem-like properties upon transformation. Besides, loss of RAB25 and overexpression of H-RAS61L resulted in increased expression of transcription factors Snail and Slug that drive these cells to lose E-cadherin and undergo epithelial-mesenchymal transition (EMT). This study confirms that loss of RAB25 and overexpression of mutant H-RAS can drive HMECs toward a mesenchymal stem-like state. Our findings reveal that RAB25 functions as a tumor suppressor gene, and loss of RAB25 could serve as a novel biomarker of the claudin-low type of TNBC.

Downregulated PDIA3P1 lncRNA Impairs Trophoblast Phenotype by Regulating Snail and SFRP1 in PE.

Preeclampsia (PE) manifests as a pregnancy-specific complication arising from compromised placentation characterized by inadequate trophoblast invasion. A growing body of evidence underscores the pivotal involvement of pseudogenes, a subset of long noncoding RNAs, in the pathological processes of PE. This study presents a novel finding, demonstrating a significant downregulation of the pseudogene PDIA3P1 in PE placental tissues compared to normal tissues. In vitro functional assays revealed that suppressing PDIA3P1 hindered trophoblast proliferation, invasion, and migration, concurrently upregulating the expression of secreted frizzled-related protein 1 (SFRP1). Further exploration of the regulatory role of PDIA3P1 in PE, utilizing human trophoblasts, established that PDIA3P1 exerts its function by binding to HuR, thereby enhancing the stability of Snail expression in trophoblasts. Overall, our findings suggest a crucial role for PDIA3P1 in regulating trophoblast properties and contributing to the pathogenesis of PE, offering potential targets for prognosis and therapeutic intervention.

A Novel Interaction of Slug (SNAI2) and Nuclear Actin.

Actin is a protein of central importance to many cellular functions. Its localization and activity are regulated by interactions with a high number of actin-binding proteins. In a yeast two-hybrid (Y2H) screening system, snail family transcriptional repressor 2 (SNAI2 or slug) was identified as a yet unknown potential actin-binding protein. We validated this interaction using immunoprecipitation and analyzed the functional relation between slug and actin. Since both proteins have been reported to be involved in DNA double-strand break (DSB) repair, we focused on their interaction during this process after treatment with doxorubicin or UV irradiation. Confocal microscopy elicits that the overexpression of actin fused to an NLS stabilizes complexes of slug and γH2AX, an early marker of DNA damage repair.

Dysregulation of TCONS_00006091 contributes to the elevated risk of oral squamous cell carcinoma by upregulating SNAI1, IRS and HMGA2.

In this study, we aimed to study the role of TCONS_00006091 in the pathogenesis of oral squamous cellular carcinoma (OSCC) transformed from oral lichen planus (OLP). This study recruited 108 OSCC patients which transformed from OLP as the OSCC group and 102 OLP patients with no sign of OSCC as the Control group. ROC curves were plotted to measure the diagnostic values of TCONS_00006091, miR-153, miR-370 and let-7g, and the changes in gene expressions were measured by RT-qPCR. Sequence analysis and luciferase assays were performed to analyze the molecular relationships among these genes. Cell proliferation and apoptosis were observed via MTT and FCM. TCONS_00006091 exhibited a better diagnosis value for OSCC transformed from OLP. OSCC group showed increased TCONS_00006091 expression and decreased expressions of miR-153, miR-370 and let-7g. The levels of SNAI1, IRS and HMGA2 was all significantly increased in OSCC patients. And TCONS_00006091 was found to sponge miR-153, miR-370 and let-7g, while these miRNAs were respectively found to targe SNAI1, IRS and HMGA2. The elevated TCONS_00006091 suppressed the expressions of miR-153, miR-370 and let-7g, leading to the increased expression of SNAI1, IRS and HMGA2. Also, promoted cell proliferation and suppressed apoptosis were observed upon the over-expression of TCONS_00006091. This study demonstrated that the expressions of miR-153, miR-370 and let-7g were down-regulated by the highly expressed TCONS_00006091 in OSCC patients, which accordingly up-regulated the expressions of SNAI1, IRS and HMGA2, resulting in the promoted cell proliferation and suppressed cell apoptosis.

CILP2 promotes hypertrophic scar through Snail acetylation by interaction with ACLY.

BACKGROUND & AIMS: Hypertrophic scar (HS) is a skin fibroproliferative disorder occurring after burns, surgeries or traumatic injuries, and it has caused a tremendous economic and medical burden. Its molecular mechanism is associated with the abnormal proliferation and transition of fibroblasts and excessive deposition of extracellular matrix. Cartilage intermediate layer protein 2 (CILP2), highly homologous to cartilage intermediate layer protein 1 (CILP1), is mainly secreted predominantly from chondrocytes in the middle/deeper layers of articular cartilage. Recent reports indicate that CILP2 is involved in the development of fibrotic diseases. We investigated the role of CILP2 in the progression of HS. METHODS AND RESULTS: It was found in this study that CILP2 expression was significantly higher in HS than in normal skin, especially in myofibroblasts. In a clinical cohort, we discovered that CILP2 was more abundant in the serum of patients with HS, especially in the early stage of HS. In vitro studies indicated that knockdown of CILP2 suppressed proliferation, migration, myofibroblast activation and collagen synthesis of hypertrophic scar fibroblasts (HSFs). Further, we revealed that CILP2 interacts with ATP citrate lyase (ACLY), in which CILP2 stabilizes the expression of ACLY by reducing the ubiquitination of ACLY, therefore prompting Snail acetylation and avoiding reduced expression of Snail. In vivo studies indicated that knockdown of CILP2 or ACLY inhibitor, SB-204990, significantly alleviated HS formation. CONCLUSION: CILP2 exerts a vital role in hypertrophic scar formation and might be a detectable biomarker reflecting the progression of hypertrophic scar and a therapeutic target for hypertrophic scar.

Two sequential gene expression programs bridged by cell division support long-distance collective cell migration.

The precise assembly of tissues and organs relies on spatiotemporal regulation of gene expression to coordinate the collective behavior of cells. In Drosophila embryos, the midgut musculature is formed through collective migration of caudal visceral mesoderm (CVM) cells, but how gene expression changes as cells migrate is not well understood. Here, we have focused on ten genes expressed in the CVM and the cis-regulatory sequences controlling their expression. Although some genes are continuously expressed, others are expressed only early or late during migration. Late expression relates to cell cycle progression, as driving string/Cdc25 causes earlier division of CVM cells and accelerates the transition to late gene expression. In particular, we found that the cell cycle effector transcription factor E2F1 is a required input for the late gene CG5080. Furthermore, whereas late genes are broadly expressed in all CVM cells, early gene transcripts are polarized to the anterior or posterior ends of the migrating collective. We show this polarization requires transcription factors Snail, Zfh1 and Dorsocross. Collectively, these results identify two sequential gene expression programs bridged by cell division that support long-distance directional migration of CVM cells.

Snail transcription factors - Characteristics, regulation and molecular targets relevant in vital cellular activities of ovarian cancer cells.

Snail transcription factors play essential roles in embryonic development and participate in many physiological processes. However, these genes have been implicated in the development and progression of various types of cancer. In epithelial ovarian cancer, high expression of these transcription factors is usually associated with the acquisition of a more aggressive phenotype and thus, considered to be a poor prognostic factor. Numerous molecular signals create a complex network of signaling pathways regulating the expression and stability of Snails, which in turn control genes involved in vital cellular functions of ovarian cancer cells, such as invasion, survival, proliferation and chemoresistance.

Identification of New Markers of Angiogenic Sprouting Using Transcriptomics: New Role for RND3.

BACKGROUND: New blood vessel formation requires endothelial cells to transition from a quiescent to an invasive phenotype. Transcriptional changes are vital for this switch, but a comprehensive genome-wide approach focused exclusively on endothelial cell sprout initiation has not been reported. METHODS: Using a model of human endothelial cell sprout initiation, we developed a protocol to physically separate cells that initiate the process of new blood vessel formation (invading cells) from noninvading cells. We used this model to perform multiple transcriptomics analyses from independent donors to monitor endothelial gene expression changes. RESULTS: Single-cell population analyses, single-cell cluster analyses, and bulk RNA sequencing revealed common transcriptomic changes associated with invading cells. We also found that collagenase digestion used to isolate single cells upregulated the Fos proto-oncogene transcription factor. Exclusion of Fos proto-oncogene expressing cells revealed a gene signature consistent with activation of signal transduction, morphogenesis, and immune responses. Many of the genes were previously shown to regulate angiogenesis and included multiple tip cell markers. Upregulation of SNAI1 (snail family transcriptional repressor 1), PTGS2 (prostaglandin synthase 2), and JUNB (JunB proto-oncogene) protein expression was confirmed in invading cells, and silencing JunB and SNAI1 significantly reduced invasion responses. Separate studies investigated rounding 3, also known as RhoE, which has not yet been implicated in angiogenesis. Silencing rounding 3 reduced endothelial invasion distance as well as filopodia length, fitting with a pathfinding role for rounding 3 via regulation of filopodial extensions. Analysis of in vivo retinal angiogenesis in Rnd3 heterozygous mice confirmed a decrease in filopodial length compared with wild-type littermates. CONCLUSIONS: Validation of multiple genes, including rounding 3, revealed a functional role for this gene signature early in the angiogenic process. This study expands the list of genes associated with the acquisition of a tip cell phenotype during endothelial cell sprout initiation.

Effect of bromodomain PHD-finger transcription factor (BPTF) on trophoblast epithelial-to-mesenchymal transition.

The trophoblast epithelial-to-mesenchymal transition (EMT) is a procedure related to embryo implantation, spiral artery establishment and fetal-maternal communication, which is a key event for successful pregnancy. Inadequate EMT is one of the pathological mechanisms of recurrent miscarriage (RM). Whole-exome sequencing revealed that the mutation of bromodomain PHD-finger transcription factor (BPTF) was strongly associated with RM. In the present study, the effects of BPTF on EMT and the underlying mechanism were investigated. We found that the expression of BPTF in the villi of RM patients was significantly downregulated. Gene Ontology (GO) analysis revealed that BPTF participated in cell adhesion. The knockdown of BPTF prevented EMT and attenuated trophoblast invasion in vitro. BPTF activated Slug transcription by binding directly to the promoter region of the Slug gene. Interestingly, the protein levels of both Slug and BPTF were decreased in the villous cytotrophoblasts (VCTs) of RM villi. In conclusion, BPTF participates in the regulation of trophoblast EMT by activating Slug expression, suggesting that BPTF defects are an important factor in RM pathogenesis.

The clinical significance of SNAIL, TWIST, and E-Cadherin expression in gastric mesentery tumor deposits of advanced gastric cancer.

Objective: To explore the relationships among the epithelial to mesenchymal transition (EMT)-related factors (SNAIL, TWIST, and E-Cadherin) and clinicopathological parameters and gastric mesangial tumor deposits (TDs) in advanced gastric cancer (AGC) patients and their value in gastric cancer prognosis judgment. Materials and Methods: The data of 190 patients who underwent radical resection of ACG were analyzed retrospectively, including 75 cases of TDs (+) and 115 cases of TDs (-). The expression of EMT-related transforming factors Snail, Twist, and E-cadherin in the primary tumor, paracancerous normal tissues, and TDs was detected by immunohistochemistry. Results: SNAIL and TWIST were overexpressed in primary tumors and TDs, whereas E-Cadherin was down-expressed in primary tumors. SNAIL was correlated significantly with tumor differentiation, lymph node metastases, and TDs (P < 0.05); TWIST was correlated strongly with tumor location, lymph node metastases, and TDs (P < 0.05); E-Cadherin was correlated closely with tumor differentiation and lymph node metastases (P < 0.05). Kaplan-Meier curves showed that SNAIL expression was correlated with DFS (P < 0.05), and TWIST expression was correlated with OS (P < 0.05). Tumor differentiation, lymph node metastasis, and TWIST expression were prognostic-independent risk factors of AGC patients (P < 0.05). Conclusion: The occurrence and development of gastric cancer and the formation of TDs may be related to EMT, analyzing the expression of EMT-related transforming proteins may be helpful to judge the prognosis of gastric cancer.

Cytolethal Distending Toxin Modulates Cell Differentiation and Elicits Epithelial to Mesenchymal Transition.

BACKGROUND: The bacterial genotoxin, cytolethal distending toxin (CDT), causes DNA damage in host cells, a risk factor for carcinogenesis. Previous studies have shown that CDT induces phenotypes reminiscent of epithelial to mesenchymal transition (EMT), a process involved in cancer initiation and progression. METHODS: We investigated different steps of EMT in response to Helicobacter hepaticus CDT and its active CdtB subunit using in vivo and in vitro models. RESULTS: Most of the steps of the EMT process were induced by CDT/CdtB and observed throughout the study in murine and epithelial cell culture models. CdtB induced cell-cell junction disassembly, causing individualization of cells and acquisition of a spindle-like morphology. The key transcriptional regulators of EMT (SNAIL and ZEB1) and some EMT markers were upregulated at both RNA and protein levels in response to CDT/CdtB. CdtB increased the expression and proteolytic activity of matrix metalloproteinases, as well as cell migration. A range of these results were confirmed in Helicobacter hepaticus-infected and xenograft murine models. In addition, colibactin, a genotoxic metabolite produced by Escherichia coli, induced EMT-like effects in cell culture. CONCLUSIONS: Overall, these data show that infection with genotoxin-producing bacteria elicits EMT process activation, supporting their role in tumorigenesis.

Co-expression of Twist and Snai1: predictor of poor prognosis and biomarker of treatment resistance in untreated prostate cancer.

BACKGROUND: Prostate cancer (PCa) remains one of the most complex tumors in men. The assessment of gene expression is expected to have a profound impact on cancer diagnosis, prognosis, and treatment decisions. The aim of this study was to determine the utility of the epithelial-mesenchymal transition (EMT) transcription factors Twist and Snai1 in the treatment of naïve prostate cancer. METHODS AND RESULTS: We analyzed formalin-fixed paraffin-embedded (FFPE) prostate tissues from 108 PCa patients and 20 control biopsies using real-time quantitative reverse transcription-polymerase chain reaction (RT-qPCR) and 2-ΔΔCt methods for Twist and Snail gene expression. The expression of Twist and Snai1 mRNA was significantly overexpressed in primary tissues of PCa patients compared with controls using ROC curve. Statistical analysis showed that the mRNAs of these two genes expression Snai1 and Twist were positively correlated with tumor development and prognostic parameters as Gleason score (p < 0.001; r = 0.707) and (p < 0.001; r = 0.627) respectively. The results of Kaplan-Meier analysis showed that mRNA expression of Snai1 and Twist genes expression were significant predictors of poor overall survival (OS) (Log rank p < 0.001) and progression-free survival (PFS) of patients (Log rank p < 0.001). Furthermore, our results showed that the expression of Snai1 and Twist genes expression in primary tissues of PCa patients could predict resistance to androgen deprivation therapy (p < 0.001) and resistance to the acidic drugs abiraterone or enzalutamide (p < 0.001). However, these two transcription factors failed to predict taxanes resistance at the time of diagnosis (p > 0.05). CONCLUSION: These results suggest that Snai1 and Twist are overexpressed during the onset and progression of PCa malignancies and may be theranostic markers of resistance to ADT, abiraterone, or enzalutamide therapy.

Ubiquitin-specific Protease 35 Promotes Gastric Cancer Metastasis by Increasing the Stability of Snail1.

Deubiquitinase (DUB) dysregulation is closely associated with multiple diseases, including tumors. In this study, we used data from The Cancer Genome Atlas and Gene Expression Omnibus databases to analyze the expression of 51 ubiquitin-specific proteases (USPs) in gastric cancer (GC) tissues and adjacent non-neoplastic tissues. The Kaplan-Meier Plotter database was used to analyze the association of the differentially expressed USPs with the overall survival of patients with GC. The results showed that five USPs (USP5, USP10, USP13, USP21, and USP35) were highly expressed in GC tissues and were associated with poor prognosis in patients with GC. Because the epithelial-mesenchymal transition enables epithelial cells to acquire mesenchymal features and contributes to poor prognosis, we investigated whether these USPs had regulatory effects on the key epithelial-mesenchymal transition transcription factor Snail1. Our results showed that USP35 exhibited the most significant regulation on Snail1. Overexpression of USP35 increased and its knockdown decreased Snail1 protein levels. Mechanistically, USP35 interacted with Snail1 and removed its polyubiquitinated chain, thereby increasing its stability. Furthermore, USP35 promoted the invasion and migration of GC cells depending on its DUB activity. USP35 knockdown exhibited the opposite effect. Snail1 depletion partially abrogated the biological effects of USP35. Experiments using nude mouse tail vein injections indicated that wild-type USP35, but not the catalytically inactive USP35-C450A mutant, dramatically enhanced cell colonization and tumorigenesis in the lungs of mice. In addition, USP35 positively correlated with Snail1 expression in clinical GC tissues. Helicobacter pylori infection increased USP35 and Snail1 expression levels. Altogether, we found that USP35 can deubiquitinate Snail1 and increase its expression, thereby contributing to the malignant progression of GC. Therefore, USP35 may serve as a viable target for GC treatment.