SNAI1 Research Articles

USP5 promotes tumor progression by stabilizing SLUG in bladder cancer.

Bladder cancer ranks as the second most prevalent urology malignancy globally. Invasive metastasis is a significant contributor to mortality among patients with bladder cancer, yet the underlying mechanisms remain elusive. Deubiquitinases are pivotal in carcinogenesis, with USP5 implicated in the malignant progression of hepatocellular carcinoma, colorectal cancer and non-small cell lung cancer. The present study assessed the role and mechanism of ubiquitin-specific proteinase 5 (USP5) in the malignant progression of bladder cancer. The association between USP5 expression and bladder cancer prognosis and stage was analyzed using The Cancer Genome Atlas database. Moreover, to elucidate the role of USP5 in bladder cancer, USP5 overexpression and knockdown cell lines were established using T24 cells. Cell viability, proliferation and migration were assessed using Cell Counting Kit-8, Transwell and scratch assays, respectively. Cyclohexanamide was used to evaluate the effect of USP5 expression on Snail family zinc finger 2 (SLUG) stability. Immunoprecipitation and immunofluorescence co-localization were utilized to probe the interaction between USP5 and SLUG. Changes in mRNA and protein levels were assessed using reverse transcription-quantitative PCR and western blotting, respectively. The results revealed that patients with bladder cancer with high USP5 expression had significantly shorter survival (P<0.05) and a higher clinicopathologic stage (P<0.05) than those with low USP5 expression. T24 cells overexpressing USP5 demonstrated significantly increased proliferation (P<0.05), invasion (P<0.05) and expression of epithelial-mesenchymal transition markers (P<0.05); whereas T24 cells with knocked-down USP5 expression revealed significantly reduced proliferation (P<0.05), invasion (P<0.05) and epithelial-mesenchymal transition markers (P<0.05). Immunoprecipitation experiments demonstrated the binding of USP5 to SLUG in bladder cancer cells, with further analysis revealing that USP5 upregulated protein levels of SLUG by inhibiting its ubiquitination. Furthermore, the treatment of bladder cancer cells with Degrasyn, a USP5 inhibitor, was associated with a significant inhibition of the proliferation (P<0.05) and invasion (P<0.05) of T24 cells. In conclusion, the findings of the present study underscore the role of USP5 in promoting the malignant progression of bladder cancer through the stabilization of SLUG. Targeting USP5 holds promise as a strategy for inhibiting bladder cancer progression.

DDX5-Targeting Fragile X Mental Retardation Protein Regulates the Wnt/β-catenin Signaling Pathway to Promote Epithelial Mesenchymal Transition in Breast Cancer

To investigate the role of fragile X mental retardation protein (FMRP) in promoting cell migration and epithelial-mesenchymal transition (EMT) in breast cancer (BC) and the potential mechanisms involved. The mRNA and protein expressions of FMRP in MCF-10A, a normal human breast epithelial cell line, and four breast cancer cell lines, including MCF-7, BT474, MDA-MB-231, and HCC1937, were analyzed by RT-PCR and Western blot. The expression of FMRP in BC tissues was measured by immunohistochemistry (IHC). FMRP expression in BC and its relationship with clinical prognosis were analyzed using GEO database. Lentiviral infection and siRNA interference were used to construct FMRP overexpression and interference vectors, respectively, and the human breast cancer cell line MCF-7 was subsequently transfected. A Control group, an interference empty vector group (the NC group), a knockdown vector group (the siFMRP group), an overexpression empty vector group (the Lv-NC group), and an overexpression vector group (the Lv-FMRP group) were set up. The migration and invasion abilities of the cells were assessed by scratch assay and Transwell assay. The expression of EMT markers, including E-cadherin, an epithelial marker, N-cadherin, an mesenchymal markers, vimentin, zinc finger E-box binding homeobox 1 (ZEB1), and snail family zinc finger 2 (Slug), in the cells of each group was determined by Western blot. The interaction between FMRP and DEAD-box RNA helicase-5 (DDX5) protein was analyzed by immunocoprecipitation combined with mass spectrometry (IP-MS). The regulatory effect of FMRP on DDX5 protein expression was assessed using the protein synthesis inhibitor cycloheximide (CHX) and proteasome inhibitor MG132. In addition, transfection with siDDX5 vector was conducted to observe whether DDX5 could reverse the effects of FMRP overexpression on cell migration and EMT. The localization and expression of β-catenin were determined by immunofluorescence staining, and the expression of core markers of Wnt/β-catenin signaling pathway was examined by Western blot. FMRP was highly expressed in BC tissues and cells (P<0.05), and overall survival (OS) and recurrence-free survival (RFS) of the FMRP high expression group were significantly lower than those of the FMRP low expression group (P<0.05). The migration ability of MCF-7 cells was weakened after FMRP knockdown, while overexpression of FMRP promoted cell migration (P<0.05). After FMRP knockdown, the expression of E-cadherin was increased, while the expression levels of N-cadherin, vimentin, ZEB1, and Slug were decreased, which inhibited the occurrence of EMT. In contrast, the overexpression of FMRP promoted the EMT process (P<0.05). FMRP interacted with DDX5 protein and promoted DDX5 protein stability by blocking the ubiquitin-proteasome pathway. DDX5 knockdown reversed the effect of FMRP overexpression to promote cell migration and EMT (P<0.05), effectively inhibited β-catenin nuclear translocation, and decreased β-catenin nuclear distribution. Furthermore, it was found that the expression of p-β-catenin, GSK3β and Axin2 protein was increased and the expression of C-myc protein was decreased after DDX5 downregulation (P<0.05). On the other hand, the expression of these proteins was reversed by combined FMRP overexpression (P<0.05). FMRP targets DDX5 and promotes BC cell migration and EMT via the activation of the Wnt/β-catenin signaling pathway.

Unveiling an anoikis-related risk model and the role of RAD9A in colon cancer

ObjectiveColorectal cancer (CRC), specifically colon adenocarcinoma, is the third most prevalent and the second most lethal form of cancer. Anoikis is found to be specialized form of programmed cell death (PCD), which plays a pivotal role in tumor progression. This study aimed to investigate the role of the anoikis related genes (ARGs) in colon cancer. MethodsConsensus unsupervised clustering, differential expression analysis, tumor mutational burden analysis, and analysis of immune cell infiltration were utilized in the study. For the analysis of RNA sequences and clinical data of COAD patients, data from the Gene Expression Omnibus (GEO) and The Cancer Genome Atlas (TCGA) were obtained. A prognostic scoring system for overall survival (OS) prediction was developed using Cox regression and LASSO regression analysis. Furthermore, loss-of-function assay was utilized to explore the role of RAD9A played in the progression of colon cancer. ResultsThe prognostic value of a risk score composed of NTRK2, EPHA2, RAD9A, CDC25C, and SNAI1 genes was significant. Furthermore, these findings suggested potential mechanisms that may influence prognosis, supporting the development of individualized treatment plans and management of patient outcomes. Further experiments confirmed that RAD9A could promote proliferation and metastasis of colon cancer cells. These effects may be achieved by affecting the phosphorylation of AKT. ConclusionDifferences in survival time and the tumor immune microenvironment (TIME) were observed between two gene clusters associated with ARGs. In addition, a prognostic risk model was established and confirmed as an independent risk factor. Furthermore, our data indicated that RAD9A promoted tumorigenicityby activating AKT in colon cancer.

Integrative analysis reveals associations between oral microbiota dysbiosis and host genetic and epigenetic aberrations in oral cavity squamous cell carcinoma.

Dysbiosis of the human oral microbiota has been reported to be associated with oral cavity squamous cell carcinoma (OSCC) while the host-microbiota interactions with respect to the potential impact of pathogenic bacteria on host genomic and epigenomic abnormalities remain poorly studied. In this study, the mucosal bacterial community, host genome-wide transcriptome and DNA CpG methylation were simultaneously profiled in tumors and their adjacent normal tissues of OSCC patients. Significant enrichment in the relative abundance of seven bacteria species (Fusobacterium nucleatum, Treponema medium, Peptostreptococcus stomatis, Gemella morbillorum, Catonella morbi, Peptoanaerobacter yurli and Peptococcus simiae) were observed in OSCC tumor microenvironment. These tumor-enriched bacteria formed 254 positive correlations with 206 up-regulated host genes, mainly involving signaling pathways related to cell adhesion, migration and proliferation. Integrative analysis of bacteria-transcriptome and bacteria-methylation correlations identified at least 20 dysregulated host genes with inverted CpG methylation in their promoter regions associated with enrichment of bacterial pathogens, implying a potential of pathogenic bacteria to regulate gene expression, in part, through epigenetic alterations. An in vitro model further confirmed that Fusobacterium nucleatum might contribute to cellular invasion via crosstalk with E-cadherin/β-catenin signaling, TNFα/NF-κB pathway and extracellular matrix remodeling by up-regulating SNAI2 gene, a key transcription factor of epithelial-mesenchymal transition (EMT). Our work using multi-omics approaches explored complex host-microbiota interactions and provided important insights into genetic and functional basis in OSCC tumorigenesis, which may serve as a precursor for hypothesis-driven study to better understand the causational relationship of pathogenic bacteria in this deadly cancer.

Ganglioside GD3 Regulates Inflammation and Epithelial-to-Mesenchymal Transition in Human Nasal Epithelial Cells.

Chronic sinusitis with nasal polyps (CRSwNP) is one of the most common chronic inflammatory diseases, and involves tissue remodeling. One of the key mechanisms of tissue remodeling is the epithelial-mesenchymal transition (EMT), which also represents one of the pathophysiological processes of CRS observed in CRSwNP tissues. To date, many transcription factors and forms of extracellular stimulation have been found to regulate the EMT process. However, it is not known whether gangliosides, which are the central molecules of plasma membranes, involved in regulating signal transmission pathways, are involved in the EMT process. Therefore, we aimed to determine the role of gangliosides in the EMT process. First, we confirmed that N-cadherin, which is a known mesenchymal marker, and ganglioside GD3 were specifically expressed in CRSwNP_NP tissues. Subsequently, we investigated whether the administration of TNF-α to human nasal epithelial cells (hNECs) resulted in the upregulation of ganglioside GD3 and its synthesizing enzyme, ST8 alpha-N-acetyl-neuraminide alpha-2,8-sialytransferase 1 (ST8Sia1), and the consequently promoted inflammatory processes. Additionally, the expression of N-cadherin, Zinc finger protein SNAI2 (SLUG), and matrix metallopeptidase 9 (MMP-9) were elevated, but that of E-cadherin, which is known to be epithelial, was reduced. Moreover, the inhibition of ganglioside GD3 expression by the siRNA or exogenous treatment of neuraminidase 3 (NEU 3) led to the suppression of inflammation and EMT. These results suggest that gangliosides may play an important role in prevention and therapy for inflammation and EMT.

KLF5 inhibits the migration and invasion in cervical cancer cell lines by regulating SNAI1.

Epithelial-mesenchymal transition (EMT) is an important biological process by which malignant tumor cells to acquire migration and invasion abilities. This study explored the role of KLF5 in the EMT process of in cervical cancer cell lines. Krüpple-like factor 5 (KLF5) is a basic transcriptional factor that plays a key role in cell-cycle arrest and inhibition of apoptosis. However, the molecular mechanism by which KLF5 mediates the biological functions of cervical cancer cell lines has not been elucidated. Here, we focus on the potential function of ELF5 in regulating the EMT process in in vitro model of cervical cancer cell lines. Western-blot and real-time quantitative PCR were used to detect the expression of EMT-related genes in HeLa cells. MTT assays, cell scratch and Transwell assays were used to assess HeLa cells proliferation and invasion capability. Using the bioinformatics tool JASPAR, we identified a high-scoring KLF5-like binding sequence in the SNAI1 gene promoter. Luciferase reporter assays was used to detect transcriptional activity for different SNAI1 promoter truncates. After overexpressing the KLF5 gene in HeLa cells, KLF5 not only significantly inhibited the invasion and migration of HeLa cells, but also increased the expression of E-cadherin and decreased the expression of N-cadherin and MMP9. In addition, the mRNA expression of upstream regulators of E-cadherin, such as SNAI1, SLUG, ZEB1/2 and TWIST1 was also decreased. Furthermore, KLF5 inhibiting the expression of the SNAI1 gene via binding its promoter region, and the EMT of Hela cells was promoted after overexpression of the SNAI1 gene. These results indicate that KLF5 can downregulate the EMT process of HeLa cells by decreasing the expression of the SNAI1 gene, thereby inhibiting the migration and invasion of HeLa cervical cancer cells.

The role of telocytes and miR-21-5p in tumorigenicity and metastasis of breast cancer stem cells.

This study aims to investigate the roles of telocytes on the metastatic properties of breast cancer stem cells (CSCs), and to re-evaluate the effect of miR-21-5p expression on CSCs following the addition of telocytes. Telocytes from human bone marrow mononuclear cells were isolated/characterised. This was followed by the isolation/characterisation of CSCs from the MDA-MB-231. miR-21-5p was both overexpressed/inhibited in CSCs. Through co-culture studies, EMT transition and oncogenic properties of CSCs were investigated by analysing changes in ALDH1 and vimentin protein levels as well as changes in the ABCC11, SNAI1, LZTFL1, Oct 3/4, E- and N-cadherin gene expression levels. With the inhibition of miR-21-5p, significant increases in LZTFL and ABCC11 were observed with the addition of telocytes. The expression of the LZTFL gene, which decreased with the overexpression of miR-21-5p, increased in CSCs after co-culture with telocytes. While an increase expression of ABCC11, SNAI1, N-Cadherin, vimentin and ALDH was observed in CSCs after overexpression of miR-21-5p, significant decreases in these expressions were observed after co-culture with telocyte. In our study, by gene/protein level analysis we demonstrated that telocytes may have the potential to reduce cancer metastasis through miR-21-5p in breast cancer progression and reduce EMT transition.

A pyrazolopyridine as a novel AhR signaling activator with anti-breast cancer properties in vitro and in vivo

Breast cancer is one of the main causes of malignancy-related deaths globally and has a significant impact on women's quality of life. Despite significant therapeutic advances, there is a medical need for targeted therapies in breast cancer. Aryl hydrocarbon receptor (AhR), a ligand-dependent transcription factor mediates responses to environment stimuli, is emerging as a unique pleiotropic target. Herein, a combined molecular simulation and in vitro investigations identified 3-(3-fluorophenyl)-1H-pyrazolo[3,4-b]pyridine (3FPP) as a novel AhR ligand in T47D and MDA-MB-231 breast cancer cells. Its agonistic effects induced formation of the AhR-AhR nuclear translocator (Arnt) heterodimer and prompted its binding to the penta-nucleotide sequence, called xenobiotic-responsive element (XRE) motif. Moreover, 3FPP augmented the promoter-driven luciferase activities and expression of AhR-regulated genes encoding cytochrome P450 1A1 (CYP1A1) and microRNA (miR)-212/132 cluster. It reduced cell viability, migration, and invasion of both cell lines through AhR signaling. These anticancer properties were concomitant with reduced levels of B-cell lymphoma 2 (BCL-2), SRY-related HMG-box4 (SOX4), snail family zinc finger 2 (SNAI2), and cadherin 2 (CDH2). In vivo, 3FPP suppressed tumor growth and activated AhR signaling in an orthotopic mouse model. In conclusion, our results introduce the fused pyrazolopyridine 3FPP as a novel AhR agonist with AhR-specific anti-breast cancer potential in vitro and in vivo.

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

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. 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-ΔΔCtmethods 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 abirateroneor enzalutamide (p < 0.001). However, these two transcription factors failed to predict taxanes resistance at the time of diagnosis (p > 0.05). 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.

The protective effect of caffeine against oxalate-induced epithelial-mesenchymal transition in renal tubular cells via mitochondrial preservation

Mitochondrial dysfunction is one of the key mechanisms for developing chronic kidney disease (CKD). Hyperoxaluria and nephrolithiasis are also associated with mitochondrial dysfunction. Increasing evidence has shown that caffeine, the main bioactive compound in coffee, exerts both anti-fibrotic and anti-lithogenic properties but with unclear mechanisms. Herein, we address the protective effect of caffeine against mitochondrial dysfunction during oxalate-induced epithelial-mesenchymal transition (EMT) in renal cells. Analyses revealed that oxalate successfully induced EMT in MDCK renal cells as evidenced by the increased expression of several EMT-related genes (i.e., Snai1, Fn1 and Acta2). Oxalate also suppressed cellular metabolic activity and intracellular ATP level, but increased reactive oxygen species (ROS). Additionally, oxalate reduced abundance of active mitochondria and induced mitochondrial fragmentation (fission). Furthermore, oxalate decreased mitochondrial biogenesis and content as evidenced by decreased expression of sirtuin-1 (SIRT1), peroxisome proliferator-activated receptor gamma coactivator-1α (PGC-1α), cytochrome c oxidase subunit 4 (COX4), and total mitochondrial proteins. Nonetheless, these oxalate-induced deteriorations in MDCK cells and their mitochondria were successfully hampered by caffeine. Knockdown of Snai1 gene by small interfering RNA (siRNA) completely abolished the effects of oxalate on suppression of cellular metabolic activity, intracellular ATP and abundance of active mitochondria, indicating that these oxalate-induced renal cell deteriorations were mediated through the Snai1 EMT-related gene. These data, at least in part, unveil the anti-fibrotic mechanism of caffeine during oxalate-induced EMT in renal cells by preserving mitochondrial biogenesis and function.

Abstract 18175: LncRNA in Monocytes of Patients With Type 2 Diabetes and Established Cardiovascular Disease Modulate the Expression of Protein-Coding Genes

Introduction: Monocytes contribute to cardiovascular complications of type 2 diabetes (T2D) through various mechanisms. Objectives: We investigated diabetes-induced changes in long non-coding RNAs (lncRNA) from monocytes of patients with T2D and established cardiovascular disease. Methods: We performed polyA capture and paired-end RNA sequencing of monocytes from 120 patients with T2D and 37 non-diabetes controls. Monocytes were sorted using FACSAria2 flow cytometer. Alignments and gene counts were done with STAR to reference GRCh38 using Gencode (v41) gene annotations. The batch correction was done with CombatSeq and differential expression analysis with EdgeR. The false discovery was controlled with the Benjamini-Hochberg procedure. Pathway analysis was done with the IPA software using differentially expressed genes (DEGs) with a p-value &lt; 0.05. Co-expression analysis was done with cdsR and Cytoscape. Results: We found two significantly upregulated lncRNAs in monocytes from diabetes patients (ENSG00000287255 and ENSG00000289424, FDR = 0.035). Pathway analysis on DEGs revealed a network affecting cellular movement, growth, and development that includes directly interacting plasma membrane genes ITGB4 and CDH1, nuclear genes HIF1a, ZEB1, ETS1, TWIST1, SNAI2, NFKB complex, and lncRNA genes SNHG29 and FBXL19-AS1 (p &lt; 1*10^ -25 ). Analysis within T2D patients revealed one lncRNA upregulated only in monocytes from patients with microvascular disease (ENSG00000261654 on chr1, FDR =0.022). Interestingly, co-expression analysis uncovered correlated expression clusters between lncRNAs and protein-coding genes, with one interesting interaction identified between the highly connected MCR1 and SNHG7, a lncRNA shown to respond to IGF-1 (insulin-like growth factor 1) . Conclusion: Monocytes from patients with diabetes have differentially expressed lncRNA genes that potentially impact diabetes-related pathways.

Effects of curcumin on Wnt/β-catenin, Hedgehog pathways and expression of EMT transcription factors in basal conditions and upon HIF1A and RELA knockdown in HeLa cells

Targeting the HIF1A and NF-κB pathways with pharmacological inhibitors or small interfering RNAs is one of the most promising aspects of cancer stem cell therapy. However, the influence of HIF1A and NF-κB modulators on downstream targets such as components of the Wnt/β-catenin and Hedgehog pathways and EMT is still poorly understood.HeLa cells were treated with 10 and 50 μM curcumin for 24 h, and the function of the Wnt/β-catenin and Hedgehog pathways and EMT transcription factors were subsequently assessed using 14 RNAs expression qPCR-based analysis. We also applied siRNA-dependent HIF1A and RELA knockdown to investigate the influence of these pathways on the expression of the above RNAs along and in combination with curcumin treatment.At the higher concentration under basal conditions, curcumin suppressed most of the targets studied, while causing a significant increase in SNAI1 expression. Knockdown of HIF1A and RELA reduced the expression of Hedgehog pathway targets. In contrast to basal conditions, the expression of EMT transcription factors appeared to be increased after knockdown in response to 50 μM curcumin.Curcumin significantly inhibited Wnt/β-catenin, Hedgehog pathways and EMT transcription factor, while inducing an increase in SNAI1 gene expression, which may be part of cell adaptation systems. Knockdown of HIF1A and RELA revealed the strong dependence of Hedgehog target expression on HIF1A and NF-κB pathways. The activation status of HIF1A and NF-κB pathways determines the expression pattern of EMT transcription factors in HeLa cells.

Combination of transcatheter arterial chemoembolization and anti-PD-L1 liposomes therapy suppressed hepatocellular carcinoma progression in mice

BackgroundHepatocellular carcinoma (HCC) is a serious life-threatened tumor with high morbidity and mortality. This study aimed to study the effects of combination TACE and anti-PD-L1 liposome drug in treating HCC in mice models. MethodsWe constructed the liposome drug with phosphatidylcholine and cholesterol and mannitol, etc. Besides, the HCC mice model was established through abdominal subcutaneous injection HepG2 cancer cells in mice, then the PE-10 polyethylene catheter was used for TACE therapy. The mice were separately received transcatheter arterial chemoembolization treatment, avelumab liposome drug therapy, and TACE combined with avelumab liposome drug therapy. Flow cytometry was used to analyze cell apoptosis. Western blot, Immunofluorescence staining, real-time PCR were performed to detect protein and gene expressions. ResultsThe liposomes drug was successfully constructed with a diameter of (125.5 ± 15.3) nm. After the mice received TACE and (or) immunotherapy, the combined liposome drug therapy significantly reduced the volume of hepatic carcinoma tissues, besides, the apoptotic rate of hepatic carcinoma cells in the combined liposome drug treatment group was increased obviously compared with other groups. Moreover, the protein TGFβR2 located in the cellular membrane was obviously down-regulated in the combined liposome drug therapy, while the expression of SMAD7 and PTPN14 was up-regulated in the treatment groups compared with the mice without treatment, besides, the protein PTPN14 was mainly located in the nucleus. Additionally, the mRNA expression of genes SNAI1 and Vimentin was significantly down-regulated in the combined liposome drug therapy. ConclusionCombination of transcatheter arterial chemoembolization and anti-PD-L1 liposome drug therapy significantly suppressed hepatocellular carcinoma proliferation and metastasis in mice models.

Cryptolepine Suppresses Colorectal Cancer Cell Proliferation, Stemness, and Metastatic Processes by Inhibiting WNT/β-Catenin Signaling.

Colorectal cancer (CRC) is the third most frequent cancer and the second leading cause of cancer-related deaths globally. Evidence shows that over 90% of CRC cases are initiated by a deregulated Wingless Integrated Type-1 (WNT)/β-catenin signaling pathway. The WNT/β-catenin pathway also promotes CRC cell proliferation, stemness, and metastasis. Therefore, modulators of the WNT/β-catenin pathway may serve as promising regimens for CRC. This study investigated the effect of cryptolepine-a plant-derived compound-on the WNT/β-catenin pathway in CRC. Two CRC cell lines, COLO205 and DLD1, were treated with cryptolepine or XAV 939 (a WNT inhibitor) in the presence or absence of WNT3a (a WNT activator). Using a tetrazolium-based assay, cryptolepine was found to reduce cell viability in a dose- and time-dependent manner and was a more potent inhibitor of viability than XAV 939. RT-qPCR analyses showed that cryptolepine reverses WNT3a-induced expression of β-catenin, c-MYC, and WISP1, suggesting that cryptolepine inhibits WNT3a-mediated activation of WNT/β-catenin signaling. Cryptolepine also repressed WNT3a-induced OCT4 and CD133 expression and suppressed colony formation of the cells, indicating that cryptolepine inhibits the stemness of CRC cells. Additionally, cryptolepine inhibited WNT3a-induced epithelial-to-mesenchymal transition by reducing the expression of SNAI1 and TWIST1 genes. In a wound healing assay, cryptolepine was found to suppress cell migration under unstimulated and WNT3a-stimulated conditions. Moreover, cryptolepine downregulated WNT3a-induced expression of MMP2 and MMP9 genes, which are involved in cancer cell invasion. Altogether, cryptolepine suppresses CRC cell proliferation, stemness, and metastatic properties by inhibiting WNT3a-mediated activation of the WNT/β-catenin signaling pathway. These findings provide a rationale for considering cryptolepine as a potential WNT inhibitor in CRC.

Analyzing the role of cancer-associated fibroblast activation on macrophage polarization.

Snail1 is a transcriptional factor required for cancer-associated fibroblast (CAF) activation, and mainly detected in CAFs in human tumors. In the mouse mammary tumor virus-polyoma middle tumor-antigen (MMTV-PyMT) model of murine mammary gland tumors, Snai1 gene deletion, besides increasing tumor-free lifespan, altered macrophage differentiation, with fewer expressing low levels of MHC class II. Snail1 was not expressed in macrophages, and in vitro polarization with interleukin-4 (IL4) or interferon-γ (IFNγ) was not altered by Snai1 gene depletion. We verified that CAF activation modified polarization of naïve bone-marrow-derived macrophages (BMDMΦs). When BMDMΦs were incubated with Snail1-expressing (active) CAFs or with conditioned medium derived from these cells, they exhibited a lower cytotoxic capability than when incubated with Snail1-deleted (inactive) CAFs. Gene expression analysis of BMDMΦs polarized by conditioned medium from wild-type or Snai1-deleted CAFs revealed that active CAFs differentially stimulated a complex combination of genes comprising genes that are normally induced by IL4, downregulated by IFNγ or not altered during the two canonical differentiations. Levels of RNAs relating to this CAF-induced alternative polarization were sensitive to inhibitors of factors specifically released by active CAFs, such as prostaglandin E2 and TGFβ. Finally, CAF-polarized macrophages promoted the activation of the immunosuppressive regulatory T cells (T-regs). Our results imply that an active CAF-rich tumor microenvironment induces the polarization of macrophages to an immunosuppressive phenotype, preventing the macrophage cytotoxic activity on tumor cells and enhancing the activation of T-reg cells.

The role of flavonoids in the regulation of epithelial-mesenchymal transition in cancer: A review on targeting signaling pathways and metastasis.

One of the hallmarks of cancer is metastasis, a process that entails the spread of cancer cells to distant regions in the body, culminating in tumor formation in secondary organs. Importantly, the proinflammatory environment surrounding cancer cells further contributes to cancer cell transformation and extracellular matrix destruction. During metastasis, front-rear polarity and emergence of migratory and invasive features are manifestations of epithelial-mesenchymal transition (EMT). A variety of transcription factors (TFs) are implicated in the execution of EMT, the most prominent belonging to the Snail Family Transcriptional Repressor (SNAI) and Zinc Finger E-Box Binding Homeobox (ZEB) families of TFs. These TFs are regulated by interaction with specific microRNAs (miRNAs), as miR34 and miR200. Among the several secondary metabolites produced in plants, flavonoids constitute a major group of bioactive molecules, with several described effects including antioxidant, antiinflammatory, antidiabetic, antiobesogenic, and anticancer effects. This review scrutinizes the modulatory role of flavonoids on the activity of SNAI/ZEB TFs and on their regulatory miRNAs, miR-34, and miR-200. The modulatory role of flavonoids can attenuate mesenchymal features and stimulate epithelial features, thereby inhibiting and reversing EMT. Moreover, this modulation is concomitant with the attenuation of signaling pathways involved in diverse processes as cell proliferation, cell growth, cell cycle progression, apoptosis inhibition, morphogenesis, cell fate, cell migration, cell polarity, and wound healing. The antimetastatic potential of these versatile compounds is emerging and represents an opportunity for the synthesis of more specific and potent agents.

KDM5 Family Demethylase Inhibitor KDOAM-25 Reduces Entry of SARS-CoV-2 Pseudotyped Viral Particles into Cells.

We studied the effect of KDM5 family demethylase inhibitors (JIB-04, PBIT, and KDOAM-25) on the penetration of SARS-CoV-2 pseudotyped viruses into differentiated Caco-2 cells and HEK293T cells with ACE2 hyperexpression. The above drugs were not cytotoxic. Only KDOAM-25 significantly reduced virus entry into the cells. The expression of ACE2 mRNA in Caco-2 significantly increased, while TMPRSS2 expression did not significantly change under these conditions. In differentiated Caco-2 cells, KDOAM-25 did not affect the expression of BRCA1, CDH1, TP53, SNAI1, VIM, and UGCG genes, for which an association with knockdown or overexpression of KDM5 demethylases or with the action of demethylase inhibitors had previously been shown. In undifferentiated Caco-2 cells, the expression of BRCA1, SNAI1, VIM, and CDH1 was significantly increased under the action of KDOAM-25.

EGR1 induces EMT in pancreatic cancer via a P300/SNAI2 pathway

BackgroundThe prognosis of pancreatic cancer patients remains relatively poor. Although some patients would receive surgical resection, distant metastasis frequently occurs within one year. Epithelial-mesenchymal transition (EMT), as a pathological mechanism in cancer progression, contributed to the local and distant metastasis of pancreatic cancer.MethodsTissue microarray analysis and immunohistochemistry assays were used to compare the expression of EGR1 in pancreatic cancer and normal pancreatic tissues. Transwell chambers were used to evaluated the migration and invasion ability of cancer cells. Immunofluorescence was utilized to assess the expression of E-cadherin. ChIP-qPCR assay was applied to verify the combination of EGR1 and SNAI2 promoter sequences. Dual-luciferase reporter assay was used to detect the gene promoter activation. Co-IP assay was conducted to verify the interaction of EGR1 and p300/CBP.ResultsEGR1 was highly expressed in pancreatic cancer rather than normal pancreatic tissues and correlated with poor prognosis and cancer metastasis. EGR1 was proved to enhance the migration and invasion ability of pancreatic cells. Besides, EGR1 was positively correlated with EMT process in pancreatic cancer, via a SNAI2-dependent pathway. P300/CBP was found to play an auxiliary role in the transcriptional activation of the SNAI2 gene by EGR1. Finally, in vivo experiments also proved that EGR1 promoted liver metastasis of pancreatic cancer.ConclusionOur findings implied the EMT-promoting effect of EGR1 in pancreatic cancer and revealed the intrinsic mechanism. Blocking the expression of EGR1 may be a new anticancer strategy for pancreatic cancer.Graphical

A genome-wide CRISPR activation screen identifies SCREEM a novel SNAI1 super-enhancer demarcated by eRNAs.

The genome is pervasively transcribed to produce a vast array of non-coding RNAs (ncRNAs). Long non-coding RNAs (lncRNAs) are transcripts of >200 nucleotides and are best known for their ability to regulate gene expression. Enhancer RNAs (eRNAs) are subclass of lncRNAs that are synthesized from enhancer regions and have also been shown to coordinate gene expression. The biological function and significance of most lncRNAs and eRNAs remain to be determined. Epithelial to mesenchymal transition (EMT) is a ubiquitous cellular process that occurs during cellular migration, homeostasis, fibrosis, and cancer-cell metastasis. EMT-transcription factors, such as SNAI1 induce a complex transcriptional program that coordinates the morphological and molecular changes associated with EMT. Such complex transcriptional programs are often subject to coordination by networks of ncRNAs and thus can be leveraged to identify novel functional ncRNA loci. Here, using a genome-wide CRISPR activation (CRISPRa) screen targeting ∼10,000 lncRNA loci we identified ncRNA loci that could either promote or attenuate EMT. We discovered a novel locus that we named SCREEM (SNAI1 cis-regulatory eRNAs expressed in monocytes). The SCREEM locus contained a cluster of eRNAs that when activated using CRISPRa induced expression of the neighboring gene SNAI1, driving concomitant EMT. However, the SCREEM eRNA transcripts themselves appeared dispensable for the induction of SNAI1 expression. Interestingly, the SCREEM eRNAs and SNAI1 were co-expressed in activated monocytes, where the SCREEM locus demarcated a monocyte-specific super-enhancer. These findings suggest a potential role for SNAI1 in monocytes. Exploration of the SCREEM-SNAI axis could reveal novel aspects of monocyte biology.

Abstract PR004: Mechanistic basis for TGF-β-induced fibrogenic EMTs in metastasis

Abstract The cytokine TGF-β is a central regulator of tissue homeostasis and regeneration through multiple coordinated effects on epithelial, immune, and mesenchymal stromal systems. Malfunctions of TGF-β signaling cause fibrosis, immune dysfunction, and cancer. As part of its multifunctional program, TGF-β induces epithelial-mesenchymal transitions (EMTs). Carcinoma cells use TGF-β to undergo EMT and adopt a highly plastic phenotype that facilitates tumor growth and metastasis. Notably, TGF-β-induced EMTs in epithelial progenitor cells are accompanied by the expression of fibrogenic factors that activate fibroblasts to produce and remodel the extracellular matrix. This not only occurs during wound healing but also in lung adenocarcinoma (LUAD) and pancreatic adenocarcinoma (PDAC) cells, suggesting that EMT and fibrogenesis are parts of an orchestrated program. We recently showed that the transcription factor RAS-Responsive Element-Binding Protein 1 (RREB1) activated by RAS-MAPK signaling synergizes with SMADs to coordinately activate the expression of EMT transcription factor Snai1 and fibrogenic genes in carcinoma progenitors (Su et al Nature 2020). Using metastasis transplantation models, we have now found that both arms of the RREB1-dependent TGF-β responses are important for metastasis. Knockout of individual fibrogenic genes in cancer cells inhibited metastasis without altering the induction of EMT by TGF-β. To address why these TGF-β target genes specifically require KRAS-activated RREB1 for transcriptional induction, we employed proteomics approaches coupled with a CRISPR-based genetic screen. With this approach we identified DXH9 and INO80 as RREB1-interacting factors essential for TGF-β activation of fibrogenic EMT programs in PDAC and LUAD cells. DXH9 and INO80 are helicases that interact and SMAD3 and RREB1 in response to TGF-β. Knockout of Dhx9 or Ino80 abolished the induction of Snai1 and fibrogenic genes by TGF-β, inhibited the LUAD metastasis, and decreased intratumoral fibrosis, thus phenocopying the knockout of Rreb1. The helicase domain of DHX9 is required for TGF-β gene responses and metastasis. Our evidence indicates that RREB1, DXH9, and INO80 function to remodel the chromatin at specific loci that constitute a TGF-β-dependent fibrogenic EMT program. This work illuminates a previously unknown cooperation between TGF-β and RAS-MAPK pathways during epithelial tissue regeneration and its cooption in carcinoma metastasis. Citation Format: Jun Ho Lee, Harihar Basnet, Francisco Sánchez-Rivera, Zhenghan Wang, Liangji Li, Joan Massagué. Mechanistic basis for TGF-β-induced fibrogenic EMTs in metastasis [abstract]. In: Proceedings of the AACR Special Conference: Cancer Metastasis; 2022 Nov 14-17; Portland, OR. Philadelphia (PA): AACR; Cancer Res 2022;83(2 Suppl_2):Abstract nr PR004.