Upregulation Of SNAI1 Research Articles

Introducing BDNF and SNAI1 as the Crucial Targeted Genes by UV Radiation.

Introduction: Due to widespread penetration of UV radiation in human life, the biological effect of UV radiation is studied through many investigations in the field of medicine. There are many assessments about UV radiation which are concerned with protein-protein interaction (PPI) network analysis. In the present study, a network analysis associated with the complementary evaluation of UV radiation on human primary melanocytes is presented. Methods: The gene expression profiles of the irradiated human primary melanocytes and the control cells were extracted from Gene Expression Omnibus (GEO) and were evaluated via PPI network analysis and action map assessment. Results: 69 significant differentially expressed genes (DEGs) were included in the main component of the PPI network. Brain-derived neurotrophic factor (BDNF), SNAI1, and SOCS1 were highlighted as the top dysregulated and hub genes. Results indicate that BDNF and SNAI1 participate in the regulatory unit including the total hubs and top dysregulated genes. Conclusion: Considerable down-regulation of BDNF and up-regulation of SNAI1 as the two critical targeted genes by UV radiation are accompanied by gross alteration in cell functions.

Targeting endogenous kidney regeneration using anti-IL11 therapy in acute and chronic models of kidney disease

The kidney has large regenerative capacity, but this is compromised when kidney damage is excessive and renal tubular epithelial cells (TECs) undergo SNAI1-driven growth arrest. Here we investigate the role of IL11 in TECs, kidney injury and renal repair. IL11 stimulation of TECs induces ERK- and p90RSK-mediated GSK3β inactivation, SNAI1 upregulation and pro-inflammatory gene expression. Mice with acute kidney injury upregulate IL11 in TECs leading to SNAI1 expression and kidney dysfunction, which is not seen in Il11 deleted mice or in mice administered a neutralizing IL11 antibody in either preemptive or treatment modes. In acute kidney injury, anti-TGFβ reduces renal fibrosis but exacerbates inflammation and tubule damage whereas anti-IL11 reduces all pathologies. Mice with TEC-specific deletion of Il11ra1 have reduced pathogenic signaling and are protected from renal injury-induced inflammation, fibrosis, and failure. In a model of chronic kidney disease, anti-IL11 therapy promotes TEC proliferation and parenchymal regeneration, reverses fibroinflammation and restores renal mass and function. These data highlight IL11-induced mesenchymal transition of injured TECs as an important renal pathology and suggest IL11 as a therapeutic target for restoring stalled endogenous regeneration in the diseased kidney.

RAC1B: A Guardian of the Epithelial Phenotype and Protector Against Epithelial-Mesenchymal Transition.

The small GTPase Ras-related C3 botulinum toxin substrate 1B (RAC1B) has been shown to potently inhibit transforming growth factor (TGF)-β1-induced cell migration and epithelial-mesenchymal transition (EMT) in pancreatic and breast epithelial cells, but the underlying mechanism has remained obscure. Using a panel of pancreatic ductal adenocarcinoma (PDAC)-derived cell lines of different differentiation stages, we show that RAC1B is more abundantly expressed in well differentiated as opposed to poorly differentiated cells. Interestingly, RNA interference-mediated knockdown of RAC1B decreased expression of the epithelial marker protein E-cadherin, encoded by CDH1, and enhanced its TGF-β1-induced downregulation, whereas ectopic overexpression of RAC1B upregulated CDH1 expression and largely prevented its TGF-β1-induced silencing of CDH1. Conversely, knockdown of RAC1B, or deletion of the RAC1B-specific exon 3b by CRISPR/Cas-mediated genomic editing, enhanced basal and TGF-β1-induced upregulation of mesenchymal markers like Vimentin, and EMT-associated transcription factors such as SNAIL and SLUG. Moreover, we demonstrate that knockout of RAC1B enhanced the cells’ migratory activity and derepressed TGF-β1-induced activation of the mitogen-activated protein kinase ERK2. Pharmacological inhibition of ERK1/2 activation in RAC1B-depleted cells rescued cells from the RAC1B knockdown-induced enhancement of cell migration, TGF-β1-induced downregulation of CDH1, and upregulation of SNAI1. We conclude that RAC1B promotes epithelial gene expression and suppresses mesenchymal gene expression by interfering with TGF-β1-induced MEK-ERK signaling, thereby protecting cells from undergoing EMT and EMT-associated responses like acquisition of cell motility.

Propofol facilitates migration and invasion of oral squamous cell carcinoma cells by upregulating SNAI1 expression

AimTo investigate the effect of propofol on the migration and invasion of oral squamous cell carcinoma (OSCC) cells and explore the underlying mechanism. Main methodsCal-27 and SCC-25 cells treated with or without propofol, then the cells metastasis were determined. The levels of SNAI1 mRNA and protein were detected by real-time PCR and western blot. Cell migration ability was evaluated by wound healing assay, and the invasion of cells was measured using transwell assay. Key findingsPropofol treatment significantly promoted cell migration and invasion of OSCC. Further mechanistic studies of the stimulating effects of propofol on OSCC cell metastasis revealed that propofol treatment dose-dependently upregulated the expression of SNAI1, a member of the Snail superfamily of zinc-finger transcription factors. Additionally, the inhibition of endogenous SNAI1 expression reversed the effect of propofol on cell migration and invasion in Cal-27 and SCC-25 cells. SignificanceOur results demonstrate that propofol at clinically relevant concentrations facilitates cell migration and invasion through up-regulation of SNAI1 in OSCC cells, and suggest propofol may not be suitable for anesthesia management in OSCC patients.

Abstract 1072: Potential biomarkers correlated with poor survival rate of melanoma patients

Abstract Malignant melanoma is an extremely aggressive tumor, responsible for 90% of skin cancer mortality. Widespread metastasis is the main cause of death in melanoma patients. Therefore, the identification of molecules related to the degree of melanoma malignancy could be used as prognostic biomarkers. In the present study, using a murine model of melanoma progression, different genes, such as Snai1, Chd1, Gata4, Id4, Cbs, Vav1, and Itga4, were first identified as presenting aberrant DNA methylation in their promoters along melanoma progression by Methylight analysis. The gene expression pattern and epigenetic regulation were validated in these murine cell lines by RT-qPCR and 5AzaCdR treatment, respectively. The genes Angpt2 and Fgf1 were also identified as differentially expressed along tumor progression in this murine model. The expression profile of these genes was also evaluated in primary human melanocytes and RGP (radial growth phase), VGP (vertical growth phase) and metastatic melanoma cell lines. Clinical and gene expression data from 460 patients were obtained from TCGA (The Cancer Genome Atlas). Using an univariate test, patients presenting tumors with low levels of Chd1, Vav1, Id4 and Fgf1, and high levels of Snai1 and Angpt2 were shown to exhibit poor overall survival rate. Indeed, the multivariate analysis using Cox regression model identified high Snai1 (HR=1.217; 95% CI 1.075-1.377; p=0.002) and Angpt2 (HR=1.186; 95% CI 1.059-1.329; p=0.003) expression and low Chd1 (HR=0.757; 95% CI 0.575-0.996; p=0.047), Fgf1 (HR=0.858; 95% CI 0.780-0.944; p=0.002) and Vav1 (HR=0.859; 95% CI 0.764-0.967; p=0.011) expression as independent prognostic factors for the overall survival rate of patients with melanoma. Also using a multivariate analysis, the low levels of Id4 promoter methylation (HR=0.689; 95% CI 0.531-0.891; p=0.045) was shown to be an independent predictive factor for poor survival rate, although no correlation was found between Id4 expression and survival rate. In conclusion, the upregulation of Snai1 and Angpt2, and the downregulation of Chd1, Vav1 and Fgf1 are associated with unfavorable survival outcome, indicating they might be valuable prognostic biomarkers for melanoma. Supported by CNPq and FAPESP. Citation Format: Alice S. Morais, Ana C. Monteiro, Fernando Andrade, Lucas Goedert, Enilza Espreáfico, Regine Schneider-Stock, André Fujiota, Miriam G. Jasiulionis. Potential biomarkers correlated with poor survival rate of melanoma patients [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2018; 2018 Apr 14-18; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2018;78(13 Suppl):Abstract nr 1072.

HR+HER2- breast cancers with growth factor receptor-mediated EMT have a poor prognosis and lapatinib downregulates EMT in MCF-7 cells.

Despite an overall good prognosis, a significant proportion of patients with hormone receptor positive human epidermal growth factor receptor 2 negative breast cancers develop distant metastases. The metastatic potential of epithelial cells is known to be regulated by tumor-stromal interaction and mediated by epithelial-to-mesenchymal transition. Hormone receptor positive human epidermal growth factor receptor 2 negative tumors were used to estimate markers of epithelial-to-mesenchymal transition, and the luminal breast cancer cell line MCF-7 was used to examine the interactions between integrins and growth factor receptors in causation of epithelial-to-mesenchymal transition. A total of 140 primary tumors were sub-divided into groups enriched for the markers of epithelial-to-mesenchymal transition (snail family transcriptional repressor 2 and integrin β6) versus those with low levels. Within the epithelial-to-mesenchymal transition+ tumors, there was a positive correlation between the transcripts of integrin β6 and growth factor receptors-human epidermal growth factor receptor 2 and epidermal growth factor receptor. In tumors enriched for epithelial-to-mesenchymal transition markers, patients with tumors with the highest quartile of growth factor receptor transcripts had a shorter disease-free survival compared to patients with low growth factor receptor expression by Kaplan-Meier analysis (log rank, p = 0.03). Epithelial-to-mesenchymal transition was induced in MCF-7 cells by treatment with transforming growth factor beta 1 and confirmed by upregulation of SNAI1 and SNAI2 transcripts, increase of vimentin and integrin β6 protein, and repression of E-cadherin. Treatment of these cells with the dual-specificity tyrosine-kinase inhibitor lapatinib led to downregulation of epithelial-to-mesenchymal transition as indicated by lower levels of SNAI1 and SNAI2 transcripts, integrin αvβ6, and matrix metalloproteinase 9 protein. The results suggest that synergistic interactions between growth factor receptors and integrin β6 could mediate epithelial-to-mesenchymal transition and migration in a subset of luminal breast cancers and lapatinib might be effective in disrupting this interaction.

Reciprocal activation between ATPase inhibitory factor 1 and NF-κB drives hepatocellular carcinoma angiogenesis and metastasis.

Hepatocellular carcinoma (HCC) is a highly vascularized tumor with frequent extrahepatic metastasis. Active angiogenesis and metastasis are responsible for rapid recurrence and poor survival of HCC. However, the mechanisms that contribute to tumor metastasis remain unclear. Here we evaluate the effects of ATPase inhibitory factor 1 (IF1), an inhibitor of the mitochondrial H(+)-adenosine triphosphate (ATP) synthase, on HCC angiogenesis and metastasis. We found that increased expression of IF1 in human HCC predicts poor survival and disease recurrence after surgery. Patients with HCC who have large tumors, with vascular invasion and metastasis, expressed high levels of IF1. Invasive tumors overexpressing IF1 were featured by active epithelial-mesenchymal transition (EMT) and increased angiogenesis, whereas silencing IF1 expression attenuated EMT and invasion of HCC cells. Mechanistically, IF1 promoted Snai1 and vascular endothelial growth factor (VEGF) expression by way of activating nuclear factor kappa B (NF-κB) signaling, which depended on the binding of tumor necrosis factor (TNF) receptor-associated factor 1 (TRAF1) to NF-κB-inducing kinase (NIK) and the disruption of NIK association with the TRAF2-cIAP2 complex. Suppression of the NF-κB pathway interfered with IF1-mediated EMT and invasion. Chromatin immunoprecipitation assay showed that NF-κB can bind to the Snai1 promoter and trigger its transcription. IF1 was directly transcribed by NF-κB, thus forming a positive feedback signaling loop. There was a significant correlation between IF1 expression and pp65 levels in a cohort of HCC biopsies, and the combination of these two parameters was a more powerful predictor of poor prognosis. IF1 promotes HCC angiogenesis and metastasis by up-regulation of Snai1 and VEGF transcription, thereby providing new insight into HCC progression and IF1 function. (Hepatology 2014;60:1659-1673).

Distinct dedifferentiation processes affect caveolin-1 expression in hepatocytes

BackgroundDedifferentiation and loss of hepatocyte polarity during primary culture of hepatocytes are major drawbacks for metabolic analyses. As a prominent profibrotic cytokine and potent inducer of epithelial mesenchymal transition (EMT), TGF-β contributes to these processes in liver epithelial cells. Yet, a distinction between culture dependent and TGF-β driven hepatocyte dedifferentiation has not been shown to date.ResultsHere, we show that in both settings, mesenchymal markers are induced. However, upregulation of Snai1 and downregulation of E-Cadherin are restricted to TGF-β effects, neglecting a full EMT of culture dependent hepatocyte dedifferentiation. Mechanistically, the latter is mediated via FAK/Src/ERK/AKT pathways leading to the induction of the oncogene caveolin-1 (Cav1). Cav1 was recently proposed as a new EMT marker, but our results demonstrate Cav1 is not up-regulated in TGF-β mediated hepatocyte EMT, thus limiting validity of its use for this purpose. Importantly, marking differences on Cav1 expression exist in HCC cell lines. Whereas well differentiated HCC cell lines exhibit low and inducible Cav1 protein levels - by TGF-β in a FAK/Src dependent manner, poorly differentiated cell lines display high Cav1 expression levels which are not further modulated by TGF-β.ConclusionsThis study draws a detailed distinction between intrinsic and TGF-β mediated hepatocyte dedifferentiation and elucidates cellular pathways involved. Additionally, by evaluating the regulation of the oncogene Cav1, we provide evidence to argue against Cav1 as a reliable EMT marker.

Abstract B20: GLI1 overexpression contributes to HCC recurrence partly through the induction of SNAI1-induced epithelial-to-mesenchymal transition

Abstract Background/Aim: Glioma-associated oncogene 1 (GLI1) is one of the most important transcription factors in the hedgehog (Hh) signaling pathway and has been shown to be involved in embryonic development and tumor progression. The epithelial-to-mesenchymal transition (EMT) is an important cellular program which contributes to invasion and metastasis of cancer. We have previously shown that GLI1 may promote HCC metastasis via EMT. Here, we demonstrate that GLI1 upregulates SNAI1 expression, induces EMT, and promotes HCC recurrence in vivo and in vitro. Methods: Gli1 mRNA was assessed in 139 HCCs by microarray and its correlation with HCC recurrence and SNAI1 mRNA expression was analyzed. In vitro, the mRNA and protein expression of GLI1 was measured in Gli1-negative Huh7 cells transfected with GU1 and GU1-expressing SNU398 cells transfected with antisense oligonucleotides targeting GU1 (GLI1 ASO). GLI1-dependent transcriptional activity was assessed with GU reporter luciferase assay and electrophoretic mobility shift assay (EMSA). The interaction between Gli1, SNAI1 and EMT was assessed by real-time PCR, Western immunoblotting and immunofluorescence. Effects of GLI1 on proliferation, viability, migration, and invasion of tumor cells were also assessed. Results: GLI1 mRNA was detected in 74 HCC tumors and found to be upregulated in 43 (58.1 %) HCCs. Increased Gli1 mRNA in HCCs was associated with tumor recurrence after resection. There was a positive correlation between GLI1 and SNAI1 mRNA expression. In HCC cells, GLI1 overexpression increased Gli1-dependent transcriptional activity, proliferation, viability, migration, and invasion of tumor cells. GU1 also increased SNAI1 expression and induced the EMT. Opposite effects were observed in GU1-knockdown models. Conclusion: Together, these findings identify a novel mechanism mediating HCC recurrence that includes GLI1-mediated activation of EMT via upregulation of SNAI1. Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the Second AACR International Conference on Frontiers in Basic Cancer Research; 2011 Sep 14-18; San Francisco, CA. Philadelphia (PA): AACR; Cancer Res 2011;71(18 Suppl):Abstract nr B20.

Abstract 3371: Expression levels of EMT-related genes in hepatocellular carcinoma

Abstract Epithelial-Mesenchymal Transition (EMT) has been recognized as a cellular process by which epithelial cells undergo mesenchymal phenotype leading to increased motility and invasion in cancer cells. We recently have reported that sorafenib exerts a potent inhibitory activity against the EMT by inhibiting MAPK signaling and SNAI1 expression in hepatocellular carcinoma (HCC). Large-scale clinical data on SNAI1 expression and the prognosis of patients with HCC was recently reported, and the overexpression of Snail and/or Twist was correlated with a worse prognosis. However, it remains largely unclear on clinico-pathological features of other EMT-related genes and whether these genes are overexpressed in HCC compared with paired non-cancer lesion of the liver. Here, we examined the mRNA expression levels of EMT-related genes including SNAI1/Snail, SNAI2/slug, ZEB1/TCF8, ZEB2/SIP1, TWIST, CDH1/E-cadherin, CDH2/N-cadherin, VIM/vimentin and FN1/fibronectin in HCC. RNA was extracted from frozen surgical HCC samples (n=48) and their paired liver samples (n=14). Real-time RT-PCR amplification was performed. Glyceraldehyde 3-phosphate dehydrogenase (GAPD) was used to normalize the expression levels in the subsequent quantitative analyses. E-cadherin was significantly downregulated in most of HCC (12/14) and those of 5 HCC were markedly downregulated below 25% of paired liver. Interestingly, we found that ZEB1 is tended to be upregulated in HCC, while ZEB2 was downregulated. Regarding EMT-inducible transcription factors, SNAI1, SNAI2, ZEB1, ZEB2 and TWIST, these expression levels were overexpressed in several HCC samples. In conclusion, our findings indicate that some HCC subpopulation actually undergo EMT via upregulation of SNAI1, SNAI2, ZEB1, ZEB2 and TWIST. Evaluation of clinico-pathological features on these expression and analysis of additional HCC samples up to 100 cases are now under way. Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 102nd Annual Meeting of the American Association for Cancer Research; 2011 Apr 2-6; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2011;71(8 Suppl):Abstract nr 3371. doi:10.1158/1538-7445.AM2011-3371

Sorafenib Inhibits the Hepatocyte Growth Factor–Mediated Epithelial Mesenchymal Transition in Hepatocellular Carcinoma

The epithelial mesenchymal transition (EMT) has emerged as a pivotal event in the development of the invasive and metastatic potentials of cancer progression. Sorafenib, a VEGFR inhibitor with activity against RAF kinase, is active against hepatocellular carcinoma (HCC); however, the possible involvement of sorafenib in the EMT remains unclear. Here, we examined the effect of sorafenib on the EMT. Hepatocyte growth factor (HGF) induced EMT-like morphologic changes and the upregulation of SNAI1 and N-cadherin expression. The downregulation of E-cadherin expression in HepG2 and Huh7 HCC cell lines shows that HGF mediates the EMT in HCC. The knockdown of SNAI1 using siRNA canceled the HGF-mediated morphologic changes and cadherin switching, indicating that SNAI1 is required for the HGF-mediated EMT in HCC. Interestingly, sorafenib and the MEK inhibitor U0126 markedly inhibited the HGF-induced morphologic changes, SNAI1 upregulation, and cadherin switching, whereas the PI3 kinase inhibitor wortmannin did not. Collectively, these findings indicate that sorafenib downregulates SNAI1 expression by inhibiting mitogen-activated protein kinase (MAPK) signaling, thereby inhibiting the EMT in HCC cells. In fact, a wound healing and migration assay revealed that sorafenib completely canceled the HGF-mediated cellular migration in HCC cells. In conclusion, we found that sorafenib exerts a potent inhibitory activity against the EMT by inhibiting MAPK signaling and SNAI1 expression in HCC. Our findings may provide a novel insight into the anti-EMT effect of tyrosine kinase inhibitors in cancer cells.

Deregulation of the Pit-1 transcription factor in human breast cancer cells promotes tumor growth and metastasis

The Pit-1 transcription factor (also know as POU1F1) plays a critical role in cell differentiation during organogenesis of the anterior pituitary in mammals and is a transcriptional activator for pituitary gene transcription. Increased expression of Pit-1 has been reported in human tumorigenic breast cells. Here, we found that Pit-1 overexpression or knockdown in human breast cancer cell lines induced profound phenotypic changes in the expression of proteins involved in cell proliferation, apoptosis, and invasion. Some of these protumorigenic effects of Pit-1 were mediated by upregulation of Snai1, an inductor of the epithelial-mesenchymal transition. In immunodeficient mice, Pit-1 overexpression induced tumoral growth and promoted metastasis in lung. In patients with invasive ductal carcinoma of the breast and node-positive tumor, high expression of Pit-1 was significantly correlated with Snai1 positivity. Notably, in these patients elevated expression of Pit-1 was significantly and independently associated with the occurrence of distant metastasis. These findings suggest that Pit-1 could help to make a more accurate prognosis in patients with node-positive breast cancer and may represent a new therapeutic target.

Hedgehog signaling, epithelial-to-mesenchymal transition and miRNA (Review)

SHH, IHH, and DHH are lipid-modified secreted proteins binding to Patched receptors, and CDON, BOC or GAS1 co-receptors. In the absence of Hedgehog signaling, GLI1 is transcriptionally repressed, GLI2 is phosphorylated by GSK3 and CK1 for the FBXW11 (betaTRCP2)-mediated degradation, and GLI3 is processed to a cleaved repressor. In the presence of Hedgehog signaling, Smoothened is relieved from Patched-mediated suppression due to the Hedgehog-dependent internalization of Patched, which leads to MAP3K10 (MST) activation and SUFU inactivation for the stabilization and nuclear accumulation of GLI family members. GLI activators then upregulate CCND1, CCND2 for cell cycle acceleration, FOXA2, FOXC2, FOXE1, FOXF1, FOXL1, FOXP3, POU3F1, RUNX2, SOX13, TBX2 for cell fate determination, JAG2, INHBC, and INHBE for stem cell signaling regulation. Hedgehog signals also upregulate SFRP1 in mesenchymal cells for WNT signaling regulation. Epithelial-to-mesenchymal transition (EMT) during embryogenesis, adult tissue homeostasis and carcinogenesis is characterized by class switch from E-cadherin to N-cadherin. SNAI1 (Snail), SNAI2 (Slug), SNAI3, ZEB1, ZEB2 (SIP1), KLF8, TWIST1, and TWIST2 are EMT regulators repressing CDH1 gene encoding E-cadherin. Hedgehog signals induce JAG2 upregulation for Notch-CSL-mediated SNAI1 upregulation, and also induce TGFbeta1 secretion for ZEB1 and ZEB2 upregulation via TGFbeta receptor and NF-kappaB. TGFbeta-mediated downregulation of miR-141, miR-200a, miR-200b, miR-200c, miR-205, and miR-429 results in upregulation of ZEB1 and ZEB2 proteins. Hedgehog signaling activation indirectly leads to EMT through FGF, Notch, TGFbeta signaling cascades, and miRNA regulatory networks. miRNAs targeted to stem cell signaling components or EMT regulators are potent drug targets; however, off-target effects should be strictly controlled before clinical application of synthetic miRNA. Peptide mimetic and RNA aptamer could also be utilized as Hedgehog signaling inhibitors or EMT suppressors.