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Melanoma is the most severe type of skin cancer and among the most malignant neoplasms in humans. With the growing incidence of melanoma, increased numbers of therapeutic options, and the potential to target specific proteins, understanding the basic mechanisms underlying the disease's progression and resistance to treatment has never been more important. LOXL3, SNAI1, and NES are key factors in melanoma genesis, regulating tumor growth, metastasis, and cellular differentiation. In our study, we explored the potential role of LOXL3, SNAI1, and NES in melanoma progression and metastasis among patients with dysplastic nevi, melanoma in situ, and BRAF+ and BRAF− metastatic melanoma, using immunofluorescence and qPCR analysis. Our results reveal a significant increase in LOXL3 expression and the highest NES expression in BRAF+ melanoma compared to BRAF−, dysplastic nevi, and melanoma in situ. As for SNAI1, the highest expression was observed in the metastatic melanoma group, without significant differences among groups. We found co-expression of LOXL3 and SNAI1 in the perinuclear area of all investigated subgroups and NES and SNAI1 co-expression in melanoma cells. These findings suggest a codependence or collaboration between these markers in melanoma EMT, suggesting new potential therapeutic interventions to block the EMT cascade that could significantly affect survival in many melanoma patients. [ABSTRACT FROM AUTHOR]

Metastasis is the primary culprit behind cancer‐related fatalities in multiple cancer types, including prostate cancer. Despite great advances, the precise mechanisms underlying prostate cancer metastasis are far from complete. By using a transgenic mouse prostate cancer model (TRAMP) with and without Phf8 knockout, we have identified a crucial role of PHF8 in prostate cancer metastasis. By complexing with E2F1, PHF8 transcriptionally upregulates SNAI1 in a demethylation‐dependent manner. The upregulated SNAI1 subsequently enhances epithelial‐to‐mesenchymal transition (EMT) and metastasis. Given the role of the abnormally activated PHF8/E2F1‐SNAI1 axis in prostate cancer metastasis and poor prognosis, the levels of PHF8 or the activity of this axis could serve as biomarkers for prostate cancer metastasis. Moreover, targeting this axis could become a potential therapeutic strategy for prostate cancer treatment. © 2024 The Pathological Society of Great Britain and Ireland. [ABSTRACT FROM AUTHOR]

Abstract Background Snail family zinc finger 1 (SNAI1) has been implicated in cancer progression and prognosis across various malignancies. This study aims to elucidate the prognostic significance of SNAI1 expression in Lung Squamous Cell Carcinoma (LUSC) using data from The Cancer Genome Atlas (TCGA) database. Methods SNAI1 expression levels in LUSC patients were stratified using X-tile software to establish optimal cut-off values. Kaplan-Meier survival analysis was performed to assess the impact of SNAI1 expression on overall survival (OS). Univariate and multivariate Cox regression analyses were conducted to evaluate the prognostic value of SNAI1, considering clinical parameters such as age, clinical stage, and TNM classification. Additionally, we explored the interaction between SNAI1 expression and metastatic status, and performed Gene Set Enrichment Analysis (GSEA) to investigate associated cellular pathways. Correlations between SNAI1 and immune checkpoint molecules were also examined. Results Kaplan-Meier analysis revealed significant differences in OS among high, medium, and low SNAI1 expression groups (p

Endothelial-to-mesenchymal transition (EndMT) is a key driver of atherosclerosis. Aerobic glycolysis is increased in the endothelium of atheroprone areas, accompanied by elevated lactate levels. Histone lactylation, mediated by lactate, can regulate gene expression and participate in disease regulation. However, whether histone lactylation is involved in atherosclerosis remains unknown. Here, we report that lipid peroxidation could lead to EndMT-induced atherosclerosis by increasing lactate-dependent histone H3 lysine 18 lactylation (H3K18la) in vitro and in vivo, as well as in atherosclerotic patients’ arteries. Mechanistically, the histone chaperone ASF1A was first identified as a cofactor of P300, which precisely regulated the enrichment of H3K18la at the promoter of SNAI1, thereby activating SNAI1 transcription and promoting EndMT. We found that deletion of ASF1A inhibited EndMT and improved endothelial dysfunction. Functional analysis based on ApoeKOAsf1aECKO mice in the atherosclerosis model confirmed the involvement of H3K18la in atherosclerosis and found that endothelium-specific ASF1A deficiency inhibited EndMT and alleviated atherosclerosis development. Inhibition of glycolysis by pharmacologic inhibition and advanced PROTAC attenuated H3K18la, SNAI1 transcription, and EndMT-induced atherosclerosis. This study illustrates precise crosstalk between metabolism and epigenetics via H3K18la by the P300/ASF1A molecular complex during EndMT-induced atherogenesis, which provides emerging therapies for atherosclerosis.

Abstract 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.

Endothelial-to-mesenchymal transition (EndMT) is a key driver of atherosclerosis. Aerobic glycolysis is increased in the endothelium of atheroprone areas, accompanied by elevated lactate levels. Histone lactylation, mediated by lactate, can regulate gene expression and participate in disease regulation. However, whether histone lactylation is involved in atherosclerosis remains unknown. Here, we report that lipid peroxidation could lead to EndMT-induced atherosclerosis by increasing lactate-dependent histone H3 lysine 18 lactylation (H3K18la) in vitro and in vivo , as well as in atherosclerotic patients' arteries. Mechanistically, the histone chaperone ASF1A was first identified as a cofactor of P300, which precisely regulated the enrichment of H3K18la at the promoter of SNAI1 , thereby activating SNAI1 transcription and promoting EndMT. We found that deletion of ASF1A inhibited EndMT and improved endothelial dysfunction. Functional analysis based on Apoe KO Asf1a ECKO mice in the atherosclerosis model confirmed the involvement of H3K18la in atherosclerosis and found that endothelium-specific ASF1A deficiency inhibited EndMT and alleviated atherosclerosis development. Inhibition of glycolysis by pharmacologic inhibition and advanced PROTAC attenuated H3K18la, SNAI1 transcription, and EndMT-induced atherosclerosis. This study illustrates precise crosstalk between metabolism and epigenetics via H3K18la by the P300/ASF1A molecular complex during EndMT-induced atherogenesis, which provides emerging therapies for atherosclerosis. Histone chaperone ASF1A and P300 together regulate histone H3 lysine 18 lactylation, which increases the expression of the endothelial-to-mesenchymal transition transcription factor SNAI1, inducing endothelial dysfunction and promoting atherosclerosis. [Display omitted] [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

Abstract 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.

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. [ABSTRACT FROM AUTHOR]

BACKGROUND: 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. OBJECTIVE: 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. METHOD: 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. RESULT: 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. CONCLUSION: 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. [ABSTRACT FROM AUTHOR]

The transcription factor Forkhead box D1 (FOXD1) is a crucial member of the FOX family and is widely expressed in human embryonic cells, where it plays a regulatory role in organogenesis. However, the precise functions and molecular mechanisms of FOXD1 in esophageal squamous cell carcinoma (ESCC) are not fully clarified. This study aimed to analyze the expression of FOXD1 in ESCC, investigate its relationship with clinicopathological features and prognosis, and elucidate its role in ESCC tumorigenesis and progression. We found a significant up-regulation of FOXD1 mRNA and protein expression in ESCC (p < 0.01), which exhibited a negative correlation with prognosis. Notably, the expression level of FOXD1, along with tumor TNM stage and lymph node metastasis, emerged as independent prognostic factors for ESCC patients (p < 0.01). In addition, we observed that FOXD1 promoted ESCC cell proliferation, migration, and invasion in vitro. Furthermore, we identified a positive correlation between FOXD1 and SNAI1 in ESCC. Through direct binding to the SNAI1 promoter, FOXD1 enhanced its transcriptional activity, thereby regulating the epithelial-mesenchymal transition (EMT) process and activating TGF-β signaling. These findings suggested that FOXD1 may function as a tumor activator and represent a potential novel therapeutic target for ESCC. [Display omitted] • FOXD1 gene and protein expression levels were closely correlated with various characteristics of ESCC tumor tissues. • FOXD1 promoted ESCC cell proliferation, migration, and invasion in vitro. • FOXD1 increased SNAI1 transcription by directly binding to its promoter. • FOXD1 upregulated SNAI1 to promote EMT and enhance ESCC cell growth, migration, and invasion. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

Colorectal cancer (CRC) is a prevalent cause of cancer and mortality on a global scale. SNAI1, a member of the zinc finger transcription superfamily, is a significant contributor to embryonic development and carcinogenesis through the process of epithelial–mesenchymal transition (EMT). While prior research utilizing CRC cells and clinical data has demonstrated that SNAI1 facilitates CRC progression through diverse mechanisms, the precise manner in which epithelial SNAI1 regulates CRC development in vivo remains unclear. In this study, colitis and colitis-associated CRC were induced through the use of intestinal epithelium-specific Snai1 knockout (Snai1 cKO) mice. Our findings indicate that Snai1 cKO mice exhibit a reduced susceptibility to acute colitis and colitis-associated CRC compared to control mice. Western-blot analysis of colon tissues revealed that Snai1 cKO mice exhibited a higher overall apoptosis level during tumor formation than control mice. No significant differences were observed in the activation of the classical p53 signaling pathway. However, Snai1 cKO mice exhibited weakened EMT and Wnt/β-catenin pathway activation. In summary, our study has provided evidence in vivo that the intestinal epithelial SNAI1 protein suppresses apoptosis, amplifies the EMT, and activates the Wnt/β-catenin signaling pathways in both early and late phases of CRC formation, thus promoting the development and progression of colitis-associated CRC. [ABSTRACT FROM AUTHOR]

Cancer cell stemness contributes significantly to intrahepatic cholangiocarcinoma (ICC) progression. However, the roles of deubiquitinating enzymes (DUBs) in ICC modulation are poorly understood. Ubiquitin specific peptidase 10 (USP10) was highly expressed in ICC spheres. The interaction between USP10 and snail family transcriptional repressor 1 (SNAI1) reduced the polyubiquitination of the SNAI1 protein and stabilized the SNAI1 protein. USP10 knockdown in RBE cells inhibited cell proliferation, promoted cell apoptosis and decreased the diameter of the formed spheres and the expression levels of CD44, EpCAM, OCT4 and SOX2. SNAI1 overexpression alleviated the effect of USP10 knockdown in RBE cells. In addition, the knockdown of USP10 attenuated the ability of RBE cells to form tumors subcutaneously in nude mice. Our results revealed that USP10 attenuates ICC cell malignancy by deubiquitinating SNAI1, indicating that USP10 could be developed as a therapeutic target for ICC treatment. [ABSTRACT FROM AUTHOR]

Xianghui Hao,1 Yingbin Hua,1 Chaohui Xie,1 Haifeng Xu1,2 1State Key Laboratory Cultivation Base, Shandong Provincial Key Laboratory of Ophthalmology, Shandong Eye Institute, Shandong First Medical University & Shandong Academy of Medical Sciences, Qingdao, People’s Republic of China; 2Qingdao Eye Hospital, Shandong First Medical University & Shandong Academy of Medical Sciences, Qingdao, People’s Republic of ChinaCorrespondence: Haifeng Xu, Qingdao Eye Hospital, Shandong Eye Institute, Shandong First Medical University & Shandong Academy of Medical Sciences, 5 Yanerdao Road, Qingdao, Shandong, 266071, People’s Republic of China, Email chxhf@126.comBackground: To explore the role and possible mechanism of miR-21 in anti-VEGF drug-induced epithelial-mesenchymal transformation (EMT) in human retinal pigment epithelium (ARPE-19) cells, and to seek more therapeutic targets to improve prognosis vision.Methods: ARPE-19 cells were exposed to clinical dosage of bevacizumab and miR-21 expression was measured by real-time polymerase chain reaction (RT-PCR) assay. MiR-21 mimic and inhibitor were transfected into bevacizumab-induced ARPE-19, the expression of α-smooth muscle actin (α-SMA), E-cadherin, and SNAI1 were detected by cell immunofluorescence and Western blotting.Results: Clinical dosage of bevacizumab caused EMT and enhanced miR-21 expression in ARPE-19 cells (P< 0.05). The inhibition of miR-21 attenuated the EMT effect of bevacizumab, while overexpression of miR-21 promoted this activity (P< 0.05). The SNAI1 was up-regulated by bevacizumab and promotion was partially suppressed by the miR-21 inhibitor and aggravated by the miR-21 mimic (P< 0.05).Conclusion: MiR-21 promotes bevacizumab-induced EMT in ARPE cells which is significantly positively correlated with SNAI1. MiR-21 might be a potential miRNA-based therapeutic target for reducing bevacizumab-induced subretinal fibrosis.Graphical Abstract: Keywords: bevacizumab, epithelial-mesenchymal transition, MiR-21, SNAI1, therapeutic target

Melanoma is the most severe type of skin cancer and among the most malignant neoplasms in humans. With the growing incidence of melanoma, increased numbers of therapeutic options, and the potential to target specific proteins, understanding the basic mechanisms underlying the disease’s progression and resistance to treatment has never been more important. LOXL3, SNAI1, and NES are key factors in melanoma genesis, regulating tumor growth, metastasis, and cellular differentiation. In our study, we explored the potential role of LOXL3, SNAI1, and NES in melanoma progression and metastasis among patients with dysplastic nevi, melanoma in situ, and BRAF+ and BRAF− metastatic melanoma, using immunofluorescence and qPCR analysis. Our results reveal a significant increase in LOXL3 expression and the highest NES expression in BRAF+ melanoma compared to BRAF−, dysplastic nevi, and melanoma in situ. As for SNAI1, the highest expression was observed in the metastatic melanoma group, without significant differences among groups. We found co-expression of LOXL3 and SNAI1 in the perinuclear area of all investigated subgroups and NES and SNAI1 co-expression in melanoma cells. These findings suggest a codependence or collaboration between these markers in melanoma EMT, suggesting new potential therapeutic interventions to block the EMT cascade that could significantly affect survival in many melanoma patients.

Breast cancer is a common tumor type among women, with a high fatality due to metastasis. Metastasis suppressors encode proteins that inhibit the metastatic cascade independent of the primary tumor growth. Raf kinase inhibitory protein (RKIP) is one of the promising metastasis suppressor candidates. RKIP is reduced or lost in aggressive variants of different types of cancer. A few pre-clinical or clinical studies have capitalized on this protein as a possible therapeutic target. In this article, we employed two breast cancer cells to highlight the role of RKIP as an antimetastatic gene. One is the low metastatic MCF-7 with high RKIP expression, and the other is MDA-MB-231 highly metastatic cell with low RKIP expression. We used high-throughput data to explore how RKIP is lost in human tissues and its effect on cell mobility. Based on our previous work recapitulating the links between RKIP and SNAI, we experimentally manipulated RKIP in the cell models through its novel upstream NME1 and investigated the subsequent genotypic and phenotypic changes. We also demonstrated that RKIP explained the uneven migration abilities of the two cell types. Furthermore, we identified the regulatory circuit that might carry the effect of an existing drug, Epirubicin, on activating gene transcription. In conclusion, we propose and test a potential strategy to reverse the metastatic capability of breast cancer cells by chemically manipulating RKIP expression. [ABSTRACT FROM AUTHOR]

Background: Compared to other breast cancer subtypes, triple-negative breast cancer (TNBC) has always been challenging for clinicians due to its aggressive behavior and lack of a specific treatment. There is a confirmed association between invasive features of tumors and increased epithelial-mesenchymal transition (EMT) process, which is consistent with a higher rate of EMT in TNBC. Methods and results: We investigated the expression of EMT-related genes, SNAI1 and MMP7, and EMT-related lncRNAs, treRNA and SBF2-AS1, in 50 TNBC tumors and 50 non-TNBC tumors to reveal more regulators and effectors involved in TNBC malignancy. In the present study, we showed the overexpression of all the studied genes and lncRNAs in TNBC tumors compared to non-TNBC samples. Moreover, a significant association was observed between MMP7 and treRNA expression levels and larger tumor size. A positive correlation between SNAI1 and lncRNA treRNA expression levels was also detected. Conclusions: Due to the differential expression and the potential diagnostic power of the studied genes, SBF2-AS1 and treRNA can be proposed as new probable biomarkers and therapeutic targets in TNBC. [ABSTRACT FROM AUTHOR]

Idiopathic pulmonary fibrosis is a progressive, irreversible lung disease that leads to respiratory failure and death. Vincamine is an indole alkaloid obtained from the leaves of Vinca minor and acts as a vasodilator. The present study aims to investigate the protective activity of vincamine against EMT in bleomycin (BLM)-induced pulmonary fibrosis via assessing the apoptotic and TGF-β1/p38 MAPK/ERK1/2 signaling pathways. In bronchoalveolar lavage fluid, protein content, total cell count, and LDH activity were evaluated. N-cadherin, fibronectin, collagen, SOD, GPX, and MDA levels were determined in lung tissue using ELISA. Bax, p53, bcl2, TWIST, Snai1, and Slug mRNA levels were examined using qRT-PCR. Western blotting was used to assess the expression of TGF-β1, p38 MAPK, ERK1/2, and cleaved caspase 3 proteins. H & E and Masson's trichrome staining were used to analyze histopathology. In BLM-induced pulmonary fibrosis, vincamine reduced LDH activity, total protein content, and total and differential cell count. SOD and GPX were also increased following vincamine treatment, while MDA levels were decreased. Additionally, vincamine suppressed the expression of p53, Bax, TWIST, Snail, and Slug genes as well as the expression of factors such as TGF-β1, p/t p38 MAPK, p/t ERK1/2, and cleaved caspase 3 proteins, and, at the same time, vincamine increased bcl2 gene expression. Moreover, vincamine restored fibronectin, N-Catherine, and collagen protein elevation due to BLM-induced lung fibrosis. In addition, the histopathological examination of lung tissues revealed that vincamine attenuated the fibrotic and inflammatory conditions. In conclusion, vincamine suppressed bleomycin-induced EMT by attenuating TGF-β1/p38 MAPK/ERK1/2/TWIST/Snai1/Slug/fibronectin/N-cadherin pathway. Moreover, it exerted anti-apoptotic activity in bleomycin-induced pulmonary fibrosis. [ABSTRACT FROM AUTHOR]

Pediatric high-grade gliomas (pHGGs) are heterogeneous, diffuse, and highly infiltrative tumors with dismal prognosis. Aberrant post-translational histone modifications with elevated histone 3 lysine trimethylation (H3K9me3) have been recently implicated in pHGGs' pathology, conferring to tumor heterogeneity. The present study investigates the potential involvement of H3K9me3 methyltransferase SETDB1 in the cellular function, progression, and clinical significance of pHGG. The bioinformatic analysis detected SETDB1 enrichment in pediatric gliomas compared to the normal brain, as well as positive and negative correlations with a proneural and mesenchymal signature, respectively. In our cohort of pHGGs, SETDB1 expression was significantly increased compared to pLGG and normal brain tissue and correlated with p53 expression, as well as reduced patients' survival. In accordance, H3K9me3 levels were also elevated in pHGG compared to the normal brain and were associated with worse patient survival. Gene silencing of SETDB1 in two patient-derived pHGG cell lines showed a significant reduction in cell viability followed by reduced cell proliferation and increased apoptosis. SETDB1 silencing further reduced cell migration of pHGG cells and the expression of the mesenchymal markers N-cadherin and vimentin. mRNA analysis of epithelial–mesenchymal transition (EMT) markers upon SETDB1 silencing showed a reduction in SNAI1 levels and downregulation of CDH2 along with the EMT regulator gene MARCKS. In addition, SETDB1 silencing significantly increased the bivalent tumor suppressor gene SLC17A7 mRNA levels in both cell lines, indicating its implication in the oncogenic process.Altogether, our findings demonstrate a predominant oncogenic role of SETDB1 in pHGG which along with elevated H3K9me3 levels correlate significantly to tumor progression and inferior patients' survival. There is evidence that targeting SETDB1 may effectively inhibit pHGG progression, providing a novel insight into the therapeutic strategies for pediatric gliomas. Key messages: SETDB1 gene expression is enriched in pHGG compared to normal brain. SETDB1 expression is increased in pHGG tissues and associates with reduced patients' survival. Gene silencing of SETDB1 reduces cell viability and migration. SETDB1 silencing affects mesenchymal markers expression. SETDB1 silencing upregulates SLC17A7 levels. SETDB1 has an oncogenic role in pHGG. [ABSTRACT FROM AUTHOR]

Abstract Background Distant metastasis is the major cause of clear cell renal cell carcinoma (ccRCC)-associated mortality. However, molecular mechanisms involved in ccRCC metastasis remain to be fully understood. With the increasing appreciation of the role of long non-coding RNAs (lncRNAs) in cancer development, progression, and treatment resistance, the list of aberrantly expressed lncRNAs contributing to ccRCC pathogenesis is expanding rapidly. Methods Bioinformatics analysis was carried out to interrogate publicly available ccRCC datasets. In situ hybridization and qRT-PCR assays were used to test lncRNA expression in human ccRCC tissues and cell lines, respectively. Chromatin immunoprecipitation and luciferase reporter assays were used to examine transcriptional regulation of gene expression. Wound healing as well as transwell migration and invasion assays were employed to monitor ccRCC cell migration and invasion in vitro. ccRCC metastasis was also examined using mouse models in vivo. RNA pulldown and RNA immunoprecipitation were performed to test RNA–protein associations, whereas RNA-RNA interactions were tested using domain-specific chromatin isolation by RNA purification. Results MILIP expression was upregulated in metastatic compared with primary ccRCC tissues. The increased MILIP expression in metastatic ccRCC cells was driven by the transcription factor AP-2 gamma (TFAP2C). Knockdown of MILIP diminished the potential of ccRCC cell migration and invasion in vitro and reduced the formation of ccRCC metastatic lesions in vivo. The effect of MILIP on ccRCC cells was associated with alterations in the expression of epithelial-to-mesenchymal transition (EMT) hallmark genes. Mechanistically, MILIP formed an RNA-RNA duplex with the snail family transcriptional repressor 1 (Snai1) mRNA and bound to Y-box binding protein 1 (YBX1). This promoted the association between the YBX1 protein and the Snai1 mRNA, leading to increased translation of the latter. Snai1 in turn played an important role in MILIP-driven ccRCC metastasis. Conclusions The TFAP2C-responsive lncRNA MILIP drives ccRCC metastasis. Targeting MILIP may thus represent a potential avenue for ccRCC treatment.

Abstract Backgound Autophagy controls levels of cellular components during normal and stress conditions; thus, it is a pivotal process for the maintenance of cell homeostasis. In cancer, autophagy protects cells from cancerous transformations that can result from genomic instability induced by reactive oxygen species or other damaged components, but it can also promote cancer survival by providing essential nutrients during the metabolic stress condition of cancer progression. However, the molecular mechanism underlying autophagy-dependent regulation of the epithelial to mesenchymal transition (EMT) and metastasis is still elusive. Methods The intracellular level of NOTCH1 intracellular domain (NICD) in several cancer cells was studied under starvation, treatment with chloroquine or ATG7-knockdown. The autophagy activity in these cells was assessed by immunocytochemistry and molecular analyses. Cancer cell migration and invasion under modulation of autophagy were determined by in vitro scratch and Matrigel assays. Results In the study, autophagy activation stimulated degradation of NICD, a key transcriptional regulator of the EMT and cancer metastasis. We also found that NICD binds directly to LC3 and that the NICD/LC3 complex associates with SNAI1 and sequestosome 1 (SQSTM1)/p62 proteins. Furthermore, the ATG7 knockdown significantly inhibited degradation of NICD under starvation independent of SQSTM1-associated proteasomal degradation. In addition, NICD degradation by autophagy associated with the cellular level of SNAI1. Indeed, autophagy inhibited nuclear translocation of NICD protein and consequently decreased the transcriptional activity of its target genes. Autophagy activation substantially suppressed in vitro cancer cell migration and invasion. We also observed that NICD and SNAI1 levels in tissues from human cervical and lung cancer patients correlated inversely with expression of autophagy-related proteins. Conclusions These findings suggest that the cellular level of NICD is regulated by autophagy during cancer progression and that targeting autophagy-dependent NICD/SNAI1 degradation could be a strategy for the development of cancer therapeutics.

Abstract Background The increasing incidence of non-alcoholic fatty liver disease (NAFLD) has been reported worldwide, which urges understanding of its pathogenesis and development of more effective therapeutical methods for this chronic disease. In this study, we aimed to investigate the effects of a LIM homeodomain transcription factor, islet1 (ISL1) on NAFLD. Methods Male C57BL/6J mice were fed with a diet high in fat content to produce NAFLD models. These models were then treated with overexpressed ISL1 (oe-ISL1), oe-Lysine-specific demethylase 6B (KDM6B), oe-SNAI1, or short hairpin RNA against SNAI1. We assessed triglyceride and cholesterol contents in the plasma and liver tissues and determined the expressions of ISL1, KDM6B and SNAI1 in liver tissues. Moreover, the in vitro model of lipid accumulation was constructed using fatty acids to explore the in vitro effect of ISL1/KDM6B/SNAI1 in NAFLD. Results The results showed that the expressions of ISL1, KDM6B, and SNAI1 where decreased, but contents of triglyceride and cholesterol increased in mice exposed to high-fat diet. ISL1 inhibited lipogenesis and promoted lipolysis and exhibited a synergizing effect with KDM6B to upregulate the expression of SNAI1. Moreover, both KDM6B and SNAI1 could inhibit lipogenesis and induce lipolysis. Importantly, the therapeutic effects of ISL1 on in vitro model of lipid accumulations was also confirmed through the modulation of KDM6B and SNAI1. Conclusions Taken together, these findings highlighted that ISL1 effectively ameliorated NAFLD by inducing the expressions of KDM6B and SNAI1, which might be a promising drug for the treatment of NAFLD.

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.

Oxaliplatin is a commonly used platinum drug for colorectal cancer (CRC). However, the treatment of CRC by oxaliplatin usually fails because of drug resistance, which results in a huge challenge in the therapy of CRC. Elucidation of molecular mechanisms may help to overcome oxaliplatin resistance of CRC. In our study, we revealed that KIAA1199 can promote oxaliplatin resistance of CRC. Mechanistically, KIAA1199 prevents oxaliplatin mediated apoptosis via up-regulated PARP1 derived from reduced endoplasmic reticulum stress induced by protein O-GlcNAcylation. In the meantime, KIAA1199 can also trigger epithelial mesenchymal transition by stabilizing SNAI1 protein via O-GlcNAcylation. Therefore, KIAA1199 has great potential to be a novel biomarker, therapeutic target for oxaliplatin resistance and metastasis of CRC.

CD73 is an emerging target in cancer due to its role in generating adenosine, a potent immunosuppressor. We found that SNAI1, a driver of epithelial-to-mesenchymal transition (EMT), upregulates CD73 in triple negative breast cancer cells. Here, we discuss the relevance of improving CD73-based therapy by combining with inhibitors of EMT.

Simple Summary: Ovarian cancer is the gynaecologic malignant tumour with the highest mortality. Most patients are already in the advanced stage when they are found, and the 5-year survival rate is only 30–40%. Recurrence and metastasis of ovarian cancer are the difficulties of treatment. This study demonstrated for the first time that fat mass and obesity-associated protein (FTO) acts as an m6A demethylase to inhibit epithelial ovarian cancer growth and metastasis. Further, we demonstrated that FTO expression is negatively correlated with the FIGO stage in patients with epithelial ovarian cancer. In addition, we described the regulatory role of FTO-IGF2BP2-SNAI1 in epithelial ovarian cancer progression and provided a novel biomarker and treatment strategy for epithelial ovarian cancer. Fat mass and obesity-associated protein (FTO) regulates critical pathways in various diseases, including malignant tumours. However, the functional link between FTO and its target genes in epithelial ovarian cancer (EOC) development remains to be elucidated. In this study, the biological functions of FTO were verified in vitro and in vivo. The m6A modification and the binding sites of SNAI1 mRNA were confirmed by m6A RNA immunoprecipitation (MeRIP) and RIP experiments. The actinomycin D assay was used to test the stability of RNA. We found that FTO was downregulated with increased m6A levels in EOC. Reduced expression of FTO was associated with a higher FIGO stage in patients with EOC. Mechanistically, FTO decreased the m6A level and stability of SNAI1 mRNA, causing downregulation of SNAI1 and inhibiting epithelial–mesenchymal transition (EMT). Furthermore, FTO-mediated downregulation of SNAI1 expression depended on IGF2BP2, which acted as an m6A reader binding to the 3′ UTR region of SNAI1 mRNA to promote its stability. In conclusion, FTO inhibits SNAI1 expression to attenuate the growth and metastasis of EOC cells in an m6A-IGF2BP2-dependent manner. Our findings suggest that the FTO-IGF2BP2-SNAI1 axis is a potential therapeutic target in EOC. [ABSTRACT FROM AUTHOR]

Blood–brain barrier (BBB) injury is involved in the pathogenesis of sepsis‐associated encephalopathy. In this study, we used dihydroartemisinin (DHA), a derivative of artemisinin, to treat a cecal ligation and puncture (CLP)‐induced mouse sepsis model and a tumour necrosis factor α (TNF‐α)‐stimulated human cerebral microvessel endothelial cells (hCMEC)/D3 cell line. We found that DHA decreased BBB permeability and increased the expression of the tight junction protein occludin (OCLN) in the CLP model. In hCMEC/D3 cells, DHA decreased TNF‐α‐induced hyperpermeability and increased the expression of OCLN. DHA also repressed SNAI1 expression in the CLP mouse model and in TNF‐α‐stimulated hCMEC/D3 cells. These data suggest that DHA protects BBB permeability during sepsis by stimulating the expression of OCLN, by downregulating the expression of the SNAI1 transcription factor. [ABSTRACT FROM AUTHOR]

Triple-negative subtype of breast cancer (TNBC) is hallmarked by frequent disease relapse and shows highest mortality rate. Although PD-1/PD-L1 immune checkpoint blockades have recently shown promising clinical benefits, the overall response rate remains largely insufficient. Hence, alternative therapeutic approaches are warranted. Given the immunosuppressive properties of CD73-mediated adenosine release, CD73 blocking approaches are emerging as attractive strategies in cancer immunotherapy. Understanding the precise mechanism regulating the expression of CD73 is required to develop effective anti-CD73-based therapy. Our previous observations demonstrate that the transcription factors driving epithelial-to-mesenchymal transition (EMT-TF) can regulate the expression of several inhibitory immune checkpoints. Here we analyzed the role of the EMT-TF SNAI1 in the regulation of CD73 in TNBC cells. We found that doxycycline-driven SNAI1 expression in the epithelial -like TNBC cell line MDA-MB-468 results in CD73 upregulation by direct binding to the CD73 proximal promoter. SNAI1-dependent upregulation of CD73 leads to increased production and release of extracellular adenosine by TNBC cells and contributes to the enhancement of TNBC immunosuppressive properties. Our data are validated in TNBC samples by showing a positive correlation between the mRNA expression of CD73 and SNAI1. Overall, our results reveal a new CD73 regulation mechanism in TNBC that participates in TNBC-mediated immunosuppression and paves the way for developing new treatment opportunities for CD73-positive TNBC.

Background: Distant metastasis is the major cause of clear cell renal cell carcinoma (ccRCC)-associated mortality. However, molecular mechanisms involved in ccRCC metastasis remain to be fully understood. With the increasing appreciation of the role of long non-coding RNAs (lncRNAs) in cancer development, progression, and treatment resistance, the list of aberrantly expressed lncRNAs contributing to ccRCC pathogenesis is expanding rapidly. Methods: Bioinformatics analysis was carried out to interrogate publicly available ccRCC datasets. In situ hybridization and qRT-PCR assays were used to test lncRNA expression in human ccRCC tissues and cell lines, respectively. Chromatin immunoprecipitation and luciferase reporter assays were used to examine transcriptional regulation of gene expression. Wound healing as well as transwell migration and invasion assays were employed to monitor ccRCC cell migration and invasion in vitro. ccRCC metastasis was also examined using mouse models in vivo. RNA pulldown and RNA immunoprecipitation were performed to test RNA–protein associations, whereas RNA-RNA interactions were tested using domain-specific chromatin isolation by RNA purification. Results: MILIP expression was upregulated in metastatic compared with primary ccRCC tissues. The increased MILIP expression in metastatic ccRCC cells was driven by the transcription factor AP-2 gamma (TFAP2C). Knockdown of MILIP diminished the potential of ccRCC cell migration and invasion in vitro and reduced the formation of ccRCC metastatic lesions in vivo. The effect of MILIP on ccRCC cells was associated with alterations in the expression of epithelial-to-mesenchymal transition (EMT) hallmark genes. Mechanistically, MILIP formed an RNA-RNA duplex with the snail family transcriptional repressor 1 (Snai1) mRNA and bound to Y-box binding protein 1 (YBX1). This promoted the association between the YBX1 protein and the Snai1 mRNA, leading to increased translation of the latter. Snai1 in turn played an important role in MILIP-driven ccRCC metastasis. Conclusions: The TFAP2C-responsive lncRNA MILIP drives ccRCC metastasis. Targeting MILIP may thus represent a potential avenue for ccRCC treatment. [ABSTRACT FROM AUTHOR]

The HAND2 transcriptional regulator controls cardiac development, and we uncover additional essential functions in the endothelial to mesenchymal transition (EMT) underlying cardiac cushion development in the atrioventricular canal (AVC). In Hand2-deficient mouse embryos, the EMT underlying AVC cardiac cushion formation is disrupted, and we combined ChIP-seq of embryonic hearts with transcriptome analysis of wild-type and mutants AVCs to identify the functionally relevant HAND2 target genes. The HAND2 target gene regulatory network (GRN) includes most genes with known functions in EMT processes and AVC cardiac cushion formation. One of these is Snai1, an EMT master regulator whose expression is lost from Hand2-deficient AVCs. Re-expression of Snai1 in mutant AVC explants partially restores this EMT and mesenchymal cell migration. Furthermore, the HAND2-interacting enhancers in the Snai1 genomic landscape are active in embryonic hearts and other Snai1-expressing tissues. These results show that HAND2 directly regulates the molecular cascades initiating AVC cardiac valve development.

Backgound: Autophagy controls levels of cellular components during normal and stress conditions; thus, it is a pivotal process for the maintenance of cell homeostasis. In cancer, autophagy protects cells from cancerous transformations that can result from genomic instability induced by reactive oxygen species or other damaged components, but it can also promote cancer survival by providing essential nutrients during the metabolic stress condition of cancer progression. However, the molecular mechanism underlying autophagy-dependent regulation of the epithelial to mesenchymal transition (EMT) and metastasis is still elusive. Methods: The intracellular level of NOTCH1 intracellular domain (NICD) in several cancer cells was studied under starvation, treatment with chloroquine or ATG7-knockdown. The autophagy activity in these cells was assessed by immunocytochemistry and molecular analyses. Cancer cell migration and invasion under modulation of autophagy were determined by in vitro scratch and Matrigel assays. Results: In the study, autophagy activation stimulated degradation of NICD, a key transcriptional regulator of the EMT and cancer metastasis. We also found that NICD binds directly to LC3 and that the NICD/LC3 complex associates with SNAI1 and sequestosome 1 (SQSTM1)/p62 proteins. Furthermore, the ATG7 knockdown significantly inhibited degradation of NICD under starvation independent of SQSTM1-associated proteasomal degradation. In addition, NICD degradation by autophagy associated with the cellular level of SNAI1. Indeed, autophagy inhibited nuclear translocation of NICD protein and consequently decreased the transcriptional activity of its target genes. Autophagy activation substantially suppressed in vitro cancer cell migration and invasion. We also observed that NICD and SNAI1 levels in tissues from human cervical and lung cancer patients correlated inversely with expression of autophagy-related proteins. Conclusions: These findings suggest that the cellular level of NICD is regulated by autophagy during cancer progression and that targeting autophagy-dependent NICD/SNAI1 degradation could be a strategy for the development of cancer therapeutics. [ABSTRACT FROM AUTHOR]

Background: The increasing incidence of non-alcoholic fatty liver disease (NAFLD) has been reported worldwide, which urges understanding of its pathogenesis and development of more effective therapeutical methods for this chronic disease. In this study, we aimed to investigate the effects of a LIM homeodomain transcription factor, islet1 (ISL1) on NAFLD. Methods: Male C57BL/6J mice were fed with a diet high in fat content to produce NAFLD models. These models were then treated with overexpressed ISL1 (oe-ISL1), oe-Lysine-specific demethylase 6B (KDM6B), oe-SNAI1, or short hairpin RNA against SNAI1. We assessed triglyceride and cholesterol contents in the plasma and liver tissues and determined the expressions of ISL1, KDM6B and SNAI1 in liver tissues. Moreover, the in vitro model of lipid accumulation was constructed using fatty acids to explore the in vitro effect of ISL1/KDM6B/SNAI1 in NAFLD. Results: The results showed that the expressions of ISL1, KDM6B, and SNAI1 where decreased, but contents of triglyceride and cholesterol increased in mice exposed to high-fat diet. ISL1 inhibited lipogenesis and promoted lipolysis and exhibited a synergizing effect with KDM6B to upregulate the expression of SNAI1. Moreover, both KDM6B and SNAI1 could inhibit lipogenesis and induce lipolysis. Importantly, the therapeutic effects of ISL1 on in vitro model of lipid accumulations was also confirmed through the modulation of KDM6B and SNAI1. Conclusions: Taken together, these findings highlighted that ISL1 effectively ameliorated NAFLD by inducing the expressions of KDM6B and SNAI1, which might be a promising drug for the treatment of NAFLD. [ABSTRACT FROM AUTHOR]

Intrahepatic cholangiocarcinoma (ICC) is one of the most commonly diagnosed malignancies worldwide, and the second most common primary liver tumor. The lack of effective diagnostic and treatment methods results in poor patient prognosis and high mortality rate. Atypical protein kinase C-ι (aPKC-ι) is highly expressed in primary and metastatic ICC tissues, and regulates epithelial mesenchymal transition (EMT) through the aPKC-ι/P-Sp1/Snail signaling pathway. Recent studies have correlated aberrant glucose metabolism with EMT. Given the vital role of FBP1 in regulating glucose metabolism in cancer cells, we hypothesized that aPKC-ι downregulates FBP1 in ICC cells through the Snai1 pathway, and enhances glycolysis and metastasis. We confirmed the ability of aPKC-ι promotes glycolysis, invasion and metastasis of cancer cells, and further demonstrated that FBP1 inhibits the malignant properties of ICC cells by antagonizing aPKC-ι. Our findings provide novel insights into the molecular mechanisms of ICC progression and metastasis, as well as a theoretical basis for exploring new treatment strategies. [ABSTRACT FROM AUTHOR]

Objectives Epithelial–mesenchymal transition (EMT) plays a role in cancer metastasis as well as in drug resistance through various mechanisms, including increased drug efflux mediated by P-glycoprotein (P-gp). In this study, we investigated the activation mechanism of P-gp, including its regulatory factors, during EMT in hepatoblastoma-derived HepG2 cells. Methods HepG2 cells were transfected with SNAI1 using human adenovirus serotype 5 vector. We quantified mRNA and protein expression levels using qRT-PCR and western blot analysis, respectively. P-gp activity was evaluated by uptake assay, and cell viability was assessed by an MTT assay. Key findings P-gp protein expression on plasma membrane was higher in SNAI1-transfected cells than in Mock cells, although there was no difference in P-gp protein level in whole cells. Among the scaffold proteins such as ezrin, radixin and moesin (ERM), only radixin was increased in SNAI1-transfected cells. Uptake of both Rho123 and paclitaxel was decreased in SNAI1-transfected cells, and this decrease was blocked by verapamil, a P-gp inhibitor. The reduced susceptibility of SNAI1-transfected cells to paclitaxel was reversed by elacridar, another P-gp inhibitor. Conclusions Increased expression of radixin during SNAI1-induced EMT leads to increased P-gp membrane expression in HepG2 cells, enhancing P-gp function and thereby increasing drug resistance. [ABSTRACT FROM AUTHOR]

Abstract Background Long noncoding RNAs (lncRNAs) are considered critical regulators in cancers; however, the clinical significance and mechanisms of MAPKAPK5-AS1 (hereinafter referred to as MK5-AS1) in colorectal cancer (CRC) remain mostly unknown. Methods In this study, quantitative real-time PCR (qPCR) and western blotting were utilized to detect the levels of MK5-AS1, let-7f-1-3p and MK5 (MAPK activated protein kinase 5) in CRC tissues and cell lines. The biological functions of MK5-AS1, let-7f-1-3p and MK5 in CRC cells were explored using Cell Counting Kit-8 (CCK8), colony formation and transwell assays. The potential mechanisms of MK5-AS1 were evaluated by RNA pull-down, RNA immunoprecipitation (RIP), dual luciferase reporter assay, chromatin immunoprecipitation (ChIP) and bioinformatics analysis. The effects of MK5-AS1 and MK5 on CRC were investigated by a xenotransplantation model. Results We confirmed that MK5-AS1 was significantly increased in CRC tissues. Knockdown of MK5-AS1 suppressed cell migration and invasion in vitro and inhibited lung metastasis in mice. Mechanistically, MK5-AS1 regulated SNAI1 expression by sponging let-7f-1-3p and cis-regulated the adjacent gene MK5. Moreover, MK5-AS1 recruited RBM4 and eIF4A1 to promote the translation of MK5. Our study verified that MK5 promoted the phosphorylation of c-Jun, which activated the transcription of SNAI1 by directly binding to its promoter. Conclusions MK5-AS1 cis-regulated the nearby gene MK5 and acted as a let-7f-1-3p sponge, playing a vital role in CRC tumorigenesis. This study could provide novel insights into molecular therapeutic targets of CRC.

High‐mobility group protein B1 (HMGB1) has important functions in cancer cell proliferation and metastasis. However, the mechanisms of HMGB1 function in non‐small‐cell lung cancer (NSCLC) remain unclear. This study aimed to investigate the underlying mechanism of HMGB1‐dependent tumor cell proliferation and NSCLC metastasis. Firstly, we found high HMGB1 expression in NSCLC and showed that HMBG1 promoted proliferation, migration, and invasion of NSCLC cells. HMGB1 could bind to SNAI1 promoter and activate the expression of SNAI1. In addition, HMGB1 could transcriptionally regulate the lncRNA RSF1‐IT2. RSF1‐IT2 was found to function as ceRNA, sponging miR‐129‐5p, which targets SNAI1. Notably, HMGB1 was also identified as a target of miR‐129‐5p, which indicates the establishment of a positive feedback loop. Consequently, high expression of RSF1‐IT2 and SNAI1 was found to closely correlate with tumor progression in both HMGB1‐overexpressing xenograft nude mice and patients with NSCLC. Taken together, our findings provide new insights into molecular mechanisms of HMGB1‐dependent tumor metastasis. Components of the HMGB1–RSF1‐IT2–miR‐129‐5p–SNAI1 pathway may have a potential as prognostic and therapeutic targets in NSCLC.

Intrahepatic cholangiocarcinoma (ICC) is one of the most commonly diagnosed malignancies worldwide, and the second most common primary liver tumor. The lack of effective diagnostic and treatment methods results in poor patient prognosis and high mortality rate. Atypical protein kinase C-ι (aPKC-ι) is highly expressed in primary and metastatic ICC tissues, and regulates epithelial mesenchymal transition (EMT) through the aPKC-ι/P-Sp1/Snail signaling pathway. Recent studies have correlated aberrant glucose metabolism with EMT. Given the vital role of FBP1 in regulating glucose metabolism in cancer cells, we hypothesized that aPKC-ι downregulates FBP1 in ICC cells through the Snai1 pathway, and enhances glycolysis and metastasis. We confirmed the ability of aPKC-ι promotes glycolysis, invasion and metastasis of cancer cells, and further demonstrated that FBP1 inhibits the malignant properties of ICC cells by antagonizing aPKC-ι. Our findings provide novel insights into the molecular mechanisms of ICC progression and metastasis, as well as a theoretical basis for exploring new treatment strategies.

Different cellular mechanisms contribute to osteocyte development. And while critical roles for members of the zinc finger protein SNAI family (SNAIs) have been discussed in cancer‐related models, there are few reviews summarizing their importance for chondrocyte‐to‐osteocyte development. To help fill this gap, we review the roles of SNAIs in the development of mature osteocytes from chondrocytes, including the regulation of chondro‐ and osteogenesis through different signaling pathways and in programmed cell death. We also discuss how epigenetic factors—including DNA methylation, histone methylation and acetylation, and noncoding RNAs—contribute differently to both chondrocyte and osteocyte development. To better grasp the important roles of SNAIs in bone development, we also review genotype–phenotype correlations in different animal models. We end with comments about the possible importance of the SNAI family in cartilage/bone development and the potential applications for therapeutic goals. [ABSTRACT FROM AUTHOR]

Background: Visfatin acts as an oncogenic factor in numerous tumors through a variety of cellular processes. Visfatin has been revealed to promote cell migration and invasion in gastric cancer (GC). Snai1 is a well-known regulator of EMT process in cancers. However, the relationship between visfatin and snai1 in GC remains unclear. The current study aimed to explore the role of visfatin in GC. Methods: The RT-qPCR and western blot analysis were used to measure RNA and protein levels, respectively. The cell migration and invasion were tested by Trans-well assays and western blot analysis. Results: Visfatin showed upregulation in GC cells. Additionally, Visfatin with increasing concentration facilitated epithelial-mesenchymal transition (EMT) process by increasing E-cadherin and reducing N-cadherin and Vimentin protein levels in GC cells. Moreover, endogenous overexpression and knockdown of visfatin promoted and inhibited migratory and invasive abilities of GC cells, respectively. Then, we found that snai1 protein level was positively regulated by visfatin in GC cells. In addition, visfatin activated the NF-κB signaling to modulate snai1 protein expression. Furthermore, the silencing of snai1 counteracted the promotive impact of visfatin on cell migration, invasion and EMT process in GC. Conclusion: Visfatin facilitates cell migration, invasion and EMT process by targeting snai1 via the NF-κB signaling, which provides a potential insight for the treatment of GC. [ABSTRACT FROM AUTHOR]

Molecular insights into tumorigenesis have uncovered intimate correlation of SNAI1 with tumor malignancy. Herein, to explore merits of SNAI1-knockdown in tumor therapy, we harnessed RNA interference tool (shSNAI1), together with chemotherapeutic doxorubicin. Owing to abundant hydroxyl groups, pullulan was attempted to be covalently conjugated with a multiple of functional moieties, including positively-charged oligoethylenimine components for electrostatic entrapment of polyanionic shSNAI1 and hydrophobic components for entrapment of lipophilic doxorubicin. Notably, the aforementioned covalent conjugations were tailored to be detachable in response to intracellular reducing microenvironment owing to redox disulfide linkage, thereby accounting for selective intracellular liberation of the therapeutic payloads. Moreover, the surface of nanomedicine was modified with hyaluronic acid, endowing not only excellent biocompatibilities but active tumor-targeting function due to its receptors (CD44) overexpressed on tumor cells. Subsequent investigations approved appreciably targeted co-delivery of shSNAI1 and doxorubicin into solid lung tumors via systemic administration and demonstrated critical contribution of SNAI1-knockdown in amplifying chemotherapeutic potencies. [Display omitted] • Nanomedicine enables co-encapsulation of genomic and chemotherapeutic payloads. • SNAI1-knockdown drastically amplifies anti-tumor chemotherapeutic potencies. • Nanomedicine enables active tumor-targeted transportation. • Nanomedicine enables selective release of therapeutic payloads in cell interior. [ABSTRACT FROM AUTHOR]

Actin-binding proteins (ABPs) and various signaling systems are involved in the process of squamous cell carcinoma of the larynx and hypopharynx (SCCLH) metastasis. The clinical significance of these proteins has not yet been determined. We analyzed the relationship between the mRNA levels of cofilin 1 (CFL1), profilin 1 (PFN1), adenylyl cyclase-associated protein 1 (CAP1), SNAI1 and RND3 and SCCLH metastasis. The serum levels of the above ABPs were estimated and the relationship between them and their mRNA expressions was analyzed. The expression levels of ABP mRNAs were measured by real-time RT-PCR in paired tissue samples taken from 54 patients with SCCLH (T1-4N0-1M0). Expression analysis was performed using the 2−ΔΔCT method. The levels of ABPs in the blood serum were measured by ELISA. Statistical analysis was carried out using the SPSS Statistica 20.0 software package. No significant difference in the mRNA gene expression in tumor tissue of patients with T1-3N0M0 SCCLH and patients with T2-4N1-2M0 SCCLH was found. High expression of RND3 mRNA was accompanied by an increase in mRNA expression of all studied ABPs. In the blood serum of T2-4N1-2M0 patients, the level of PFN1 was lower by 21% and the level of CAP1 was higher by 75% than those observed in T1-4N0M0 patients. The data obtained showed that RND3 is involved in the regulation of molecular cascades of SCCLH metastasis. PFN1 and CAP1 serum levels can be good classifiers of metastases in patients with SCCLH. [ABSTRACT FROM AUTHOR]

Resveratrol is a natural phytoalexin that has anti-inflammatory properties, reverses doxorubicin resistance, and inhibits epithelial-mesenchymal transition (EMT) in many types of cancer cells. Fusobacterium nucleatum is reportedly enriched in oral squamous cell carcinoma (OSCC) tissues compared to adjacent normal tissues, sparking interest in the relationship between F. nucleatum and OSCC. Recently, F. nucleatum was shown to be associated with EMT in OSCC. In the present study, we aimed to investigate the effects of the natural plant compound resveratrol on F. nucleatum- induced EMT in OSCC. F. nucleatum was co-cultured with OSCC cells, with a multiplicity of infection (MOI) of 300:1. Resveratrol was used at a concentration of 10 μM. Cell Counting Kit-8 and wound healing assays were performed to examine the viability and migratory ability of OSCC cells. Subsequently, real-time RT-PCR was performed to investigate the gene expression of EMT-related markers. Western blotting and immunofluorescence analyses were used to further analyze the expression of the epithelial marker E-cadherin and the EMT transcription factor SNAI1. Co-cultivation with F. nucleatum did not significantly enhance cell viability. The co-cultured cells displayed similarities to the positive control of EMT, exhibiting enhanced migration and expression changes in EMT-related markers. SNAI1 was significantly upregulated, whereas E-cadherin, was significantly downregulated. Notably, resveratrol inhibited F. nucleatum- induced cell migration, decreasing the expression of SNAI1. Resveratrol inhibited F. nucleatum- induced EMT by downregulating SNAI1, which may provide a target for OSCC treatment. • F. nucleatum facilitates the progression of OSCC by promoting EMT. • Resveratrol downregulates the crucial EMT transcription factor SNAI1. • Resveratrol inhibits F. nucleatum- induced EMT in OSCC cells. [ABSTRACT FROM AUTHOR]

Liver injury stimulates hepatocyte replication and hepatic stellate cell (HSC) activation, thereby driving liver regeneration. Aberrant HSC activation induces liver fibrosis. However, mechanisms underlying liver regeneration and fibrosis remain poorly understood. Here, we identify hepatic Snai1 and Snai2 as important transcriptional regulators for liver regeneration and fibrosis. Partial hepatectomy or CCl4 treatment increases occupancies of Snai1 and Snai2 on cyclin A2 and D1 promoters in the liver. Snai1 and Snai2 in turn increase promoter H3K27 acetylation and cyclin A2/D1 expressions. Hepatocyte-specific deletion of both Snai1 and Snai2 , but not one alone, suppresses liver cyclin A2/D1 expression and regenerative hepatocyte proliferation after hepatectomy or CCl4 treatments but augments CCl4-stimulated HSC activation and liver fibrosis. Conversely, Snai2 overexpression in the liver enhances hepatocyte replication and suppresses liver fibrosis after CCl4 treatment. These results suggest that hepatic Snai1 and Snai2 directly promote, via histone modifications, reparative hepatocyte replication and indirectly inhibit liver fibrosis. [Display omitted] • Snai1 and Snai2 activate cyclin A2 and D1 genes via histone modifications • Deletion of both hepatic Snai1 and Snai2 , but not one alone, impairs liver regeneration • Deletion of both hepatic Snai1 and Snai2 , but not one alone, augments liver fibrosis • Snai2 overexpression accelerates liver regeneration and suppresses liver fibrosis Wang et al. show that hepatic Snai1 and Snai2 proteins support liver regeneration and defend against liver fibrosis. Snai1 and Snai2 stimulate regenerative hepatocyte replication by regulating transcriptions of cell-cycle genes. The Snai1/Snai2 pathway provides a genomic paradigm for studying liver injury, regeneration, and fibrosis. [ABSTRACT FROM AUTHOR]

The Snail family of zinc-finger transcription factors are evolutionarily conserved proteins that control processes requiring cell movement. Specifically, they regulate epithelial-to-mesenchymal transitions (EMT) where an epithelial cell severs intercellular junctions, degrades basement membrane and becomes a migratory, mesenchymal-like cell. Interestingly, Slug expression has been observed in angiogenic endothelial cells (EC) in vivo, suggesting that angiogenic sprouting may share common attributes with EMT. Here, we demonstrate that sprouting EC in vitro express both Slug and Snail, and that siRNA-mediated knockdown of either inhibits sprouting and migration in multiple in vitro angiogenesis assays. We find that expression of MT1-MMP, but not of VE-Cadherin, is regulated by Slug and that loss of sprouting as a consequence of reduced Slug expression can be reversed by lentiviral-mediated re-expression of MT1-MMP. Activity of MMP2 and MMP9 are also affected by Slug expression, likely through MT1-MMP. Importantly, we find enhanced expression of Slug in EC in human colorectal cancer samples compared with normal colon tissue, suggesting a role for Slug in pathological angiogenesis. In summary, these data implicate Slug as an important regulator of sprouting angiogenesis, particularly in pathological settings.

The study analyzes the expression of protein genes involved in intracellular signaling pathways associated with a profibrotic response, activation of epithelial-mesenchymal and endothelial-mesenchymal transitions, in modeling tuberculous granulomatosis and pharmaceutical effects. Material and methods. The study was performed on male BALB/c mice aged two months and weighing 18–22 g. Generalized tuberculous granulomatosis was simulated by a single intravenous (retro-orbital) injection of 0.5 mg BCG vaccine in 0.2 ml of isotonic aqueous NaCl solution (SS), after 4 months a part of mice started to receive treatment drugs, after 2 months the animals were sacrificed by decapitation (6 months after BCG vaccine administration) and their lung tissues were collected. Mice were divided into 6 groups, 5 males in each: intact, which were intravenously into the retro-orbital sinus injected with 0.2 ml SS (C); infected with BCG and receiving SS intraperitoneal injections (BS); infected with BCG and received intraperitoneal injections of isonicotinic acid hydrazide solution (INAH) (BI); infected with BCG and received intraperitoneal injections of dextrazide solution (conjugate of 40 kDa oxidized dextran and INAH) (BD); infected with BCG and received intraperitoneal or inhalation injections of solution of molecular-nanosomal pharmaceutical compositions of oxidized dextran (MNPC) (BMP and BMH, respectively). Finally, the expression of mRNA of matrix metalloproteinase 9, type III procollagen, TGF-β, and transcription factors ZEB1 and Snai1 was determined by real-time PCR in mice lung tissue. Results. The modeling of generalized tuberculous granulomatosis was found to be accompanied by the induction of epithelial-mesenchymal transition and the activation of profibrotic processes, which after 6 months was manifested in increase of the type III collagen α1-chain and TGF-β mRNA expression. Administration of traditional (INAH) and original (dextrazide, MNPC) preparations with anti-tuberculosis activity within two months has inhibitory activity of varying severity in relation to various markers of these processes.

Thymoquinone (TQ), the main active constituent of Nigella sativa seeds, has been shown to play a role in antioxidation, anti‐inflammation, and antitumor. Recent studies have demonstrated that TQ contributes to the suppression of liver fibrosis. Abnormal activated epithelial‐mesenchymal transition (EMT) promotes the activation of hepatic stellate cells (HSCs). However, whether the antifibrotic effects of TQ occur through inhibiting EMT is largely unknown. In this study, it was found that TQ ameliorated liver fibrosis and collagen accumulation in carbon tetrachloride (CCl4) mice. In vitro, TQ inhibited HSC activation including reduced proliferation, α‐smooth muscle actin, and collagen. In addition, TQ markedly suppressed the EMT process, with enhanced E‐cadherin and reduced desmin. Notably, snail family transcriptional repressor 1 (Snai1), the EMT master transcription factor, was obviously inhibited by TQ in vivo and in vitro. Further studies demonstrated that Snai1 was a target of microRNA‐30a (miR‐30a), which was upregulated by TQ. Interestingly, the effects of TQ on HSC activation and EMT were almost inhibited by miR‐30a inhibitor. Collectively, we demonstrate that TQ inhibits HSC activation, at least in part, via regulation of miR‐30a and Snai1. TQ upregulates miR‐30a expression, resulting in a reduced Snai1 level as well as EMT process inactivation, which contributes to the inhibition of HSC activation. TQ may be a potential therapeutic agent for liver fibrosis. [ABSTRACT FROM AUTHOR]