Claudin-7 downregulation induces metastasis and invasion in colorectal cancer via the promotion of epithelial-mesenchymal transition

The dysregulation of the tight junctions (TJs) protein claudin-7 is closely related to the development and metastasis of colorectal cancer (CRC). The aim of this study was to investigate the expression of claudin-7 and characterize the relationship between claudin-7 expression and epithelial-mesenchymal transition (EMT) in CRC. In this study, the expression of claudin-7, E-cadherin, vimentin and snail-1 was detected by immunohistochemistry (IHC) in a set of 80 CRC specimens comprising 20 specimens each of well-differentiated, moderately differentiated, poorly differentiated and liver metastases tissues. The correlation between claudin-7 and EMT-related proteins in the stably transfected claudin-7 knockdown HCT116?cell line was analyzed by IHC, immunofluorescence (IF), Western blotting (WB) and nude mouse xenograft models. The results revealed that the expression of claudin-7 was downregulated as CRC tissue differentiation grade decreased, and that low claudin-7 expression corresponded to the downregulation of E-cadherin (r?=?0.725, p?<?0.001) and upregulation of vimentin (r?=??0.376, p?=?0.001) and snail-1 (r?=??0.599, p?<?0.001). Additionally, in the claudin-7 knockdown HCT116?cell line, the staining intensity and expression of E-cadherin was decreased, while the immunoreactivity and expression of vimentin and snail-1 was increased. Futhermore, the result of tumor formation experiment was consistent with CRC tissues. In conclusion, the expression of claudin-7 in CRC is downregulated as differentiation grade decreases. Claudin-7 downregulation may promote the invasion and metastasis of CRC by regulating EMT. Our results provide new perspectives for a potential therapeutic target for CRC.     

Aqueous extract of tobacco induces mitochondrial potential dependent cell death and epithelial-mesenchymal transition in gingival epithelial cells

Smokeless tobacco habits are detrimental to oral health. A correlation between tobacco use and local epithelial tissue damage exists. Yet, the underlying cellular mechanism is not precisely characterized. This study assessed the dose-dependent action of Smokeless tobacco extract on gingival epithelial cells. Gingival tissue was taken from 5 healthy donors. Gingival epithelial cells were isolated by an enzymatic method and cultured up to passage 2. The cultured cells were treated with smokeless tobacco extract at 10%, 25%, 50%, and 75% volume concentration. After 48 h of incubation, MTT assay, Annexin V/PI assay, and DiIC1(5) assay were used to evaluate viability, apoptosis, and mitochondrial potential of the cells. RT-qPCR was used to determine the expression of BAX, BCL2, ECAD, NCAD, and TWIST. The Smokeless tobacco extract reduced cell viability by disrupting the mitochondrial potential and inducing apoptosis. Further, the Smokeless tobacco extract induced a dose-dependent epithelial-mesenchymal-transition in gingival epithelial cells. Apoptotic cellular death caused by tobacco extract on the gingival epithelial system was dependant on the mitochondrial potential of the cell. The results demonstrate that smokeless tobacco causes detrimental metabolic alterations of the periodontium.Featured applicationThis study elucidates the mechanism by which Smokeless tobacco products cause cellular damage to the gingival epithelium. The use of Smokeless tobacco products can lead to major cellular and surface changes in the gingiva and its appearance. The consequences of these changes are not limited to oral cancer but also increases a person’s risk for dental and periodontal disease.     

Investigating the link between epithelial-mesenchymal transition and the cancer stem cell phenotype: A mathematical approach

Under the cancer stem cell (CSC) hypothesis, sustained metastatic growth requires the dissemination of a CSC from the primary tumour followed by its re-establishment in a secondary site. The epithelial-mesenchymal transition (EMT), a differentiation process crucial to normal development, has been implicated in conferring metastatic ability on carcinomas. Balancing these two concepts has led researchers to investigate a possible link between EMT and the CSC phenotype—indeed, recent evidence indicates that, following induction of EMT in human breast cancer and related cell lines, stem cell activity increased, as judged by the presence of cells displaying the CD44^high/CD24^low phenotype and an increase in the ability of cells to form mammospheres. We mathematically investigate the nature of this increase in stem cell activity. A stochastic model is used when small number of cells are under consideration, namely in simulating the mammosphere assay, while a related continuous model is used to probe the dynamics of larger cell populations. Two scenarios of EMT-mediated CSC enrichment are considered. In the first, differentiated cells re-acquire a CSC phenotype—this model implicates fully mature cells as key subjects of de-differentiation and entails a delay period of several days before de-differentiation occurs. In the second, pre-existing CSCs experience accelerated division and increased proportion of self-renewing divisions; a lack of perfect CSC biomarkers and cell sorting techniques requires that this model be considered, further emphasizing the need for better characterization of the mammary (cancer) stem cell hierarchy. Additionally, we suggest the utility of comparing mammosphere data to computational mammosphere simulations in elucidating the growth characteristics of mammary (cancer) stem cells.     

汉黄芩素通过调控上皮间质转化抑制胃癌细胞的侵袭转移

目的:汉黄芩素是中药黄芩中的一种黄酮,具有体内外抗癌活性。然而,汉黄芩素对人胃癌细胞的作用尚不十分清楚。本研究拟探讨汉黄芩素对人胃癌细胞MGC-803侵袭转移能力的影响及其对上皮间质转化(Epithelial to Mesenchymal Transition,EMT)的作用机制。方法:采用MTT法测定汉黄芩素对人胃癌细胞MGC-803增殖能力的影响,通过划痕实验、Transwell试验检测汉黄芩素对人胃癌细胞MGC-803迁移、侵袭能力的影响。通过免疫印迹法和免疫荧光法分析汉黄芩素对EMT的影响。结果:20μM以上浓度的汉黄芩素能抑制人胃癌细胞MGC-803的增殖,不同浓度的汉黄芩素能抑制人胃癌细胞MGC-803的迁移和侵袭,且呈浓度依赖性。此外,汉黄芩素能抑制间质标记蛋白波形蛋白(Vimentin)和锌指蛋白E-盒结合同源异形盒-1(ZEB1)的表达,促进上皮标记蛋白E-钙黏蛋白(E-cadherin)的表达。结论:汉黄芩素能抑制胃癌细胞的侵袭和迁移,这一作用可能与其抑制EMT的发生有关。     

Sprouty-2对胃癌细胞上皮间质转化及侵袭转移的影响

目的:研究Sprouty2(SPRY2)基因在胃癌肿瘤细胞上皮间质转化(EMT)和侵袭转移的影响。方法:体外培养人胃癌细胞(BGC-823),采用慢病毒介导的sh RNA沉默SPRY2基因,并用实时定量PCR与Western blot检测其SPRY2、E-钙黏蛋白(E-cadherin)、波形蛋白(vimentin)的表达,采用细胞划痕实验、Transwell实验检测SPRY2基因沉默后的胃癌细胞侵袭转移能力变化。结果:在慢病毒介导sh RNA沉默SPRY2基因的人胃癌BGC-823细胞中,SPRY2的m RNA和蛋白表达明显降低(P0.05),SPRY2沉默后人胃癌细胞E-cadherin的蛋白表达增多(P0.05),vimentin的蛋白表达减少(P0.05)。此外,SPRY2沉默后,胃癌细胞迁移能力和侵袭能力明显减弱(P值均P0.05)。结论:Sprouty-2基因通过调节E-cadherin与vimentin的表达参与胃癌细胞的上皮-间质转化,进而促进胃癌细胞的迁移与侵袭。     

miR-363-3p靶向 TWIST1调控上皮间质转化抑制非小细胞肺癌A549细胞迁移和侵袭

目的探讨miR-363-3p靶向TWIST1调控非小细胞肺癌A549细胞迁移和侵袭的分子机制。 方法将体外培养的A549细胞分为空白对照组（细胞未做任何处理）;模拟物对照组（转染miR-363-3p模拟物阴性对照）;模拟物组（转染miR-363-3p模拟物）;后期实验另设：模拟物+ pcDNA组（转染miR-363-3p模拟物和pcDNA3.1空载体质粒）;模拟物+ TWIST1组（转染miR-363-3p模拟物和pcDNA3.1-TWIST1过表达质粒）。采用RT-PCR检测细胞中miR-363-3p的表达,Western blot检测细胞中TWIST1蛋白和上皮间质转化（EMT）相关蛋白Vimentin、E-cadherin的表达,Transwell小室实验检测细胞的迁移和侵袭。双荧光素酶报告基因实验检测miR-363-3p和TWIST1的靶向关系。两组间比较采用独立样本t检验,多组间比较采用单因素方差分析,组间两两比较采用LSD-t检验。 结果与空白对照组和模拟物对照组比较,模拟物组A549细胞中miR-363-3p表达水平（1.00±0.08、0.97±0.05比3.82±0.45）升高,TWIST1 mRNA （1.00±0.06、0.98±0.06比0.39±0.02）和蛋白的表达水平（0.81±0.05、0.78±0.06比0.42±0.02）降低,差异具有统计学意义（P均< 0.05）。与空白对照组和模拟物对照组比较,模拟物组A549细胞Vimentin蛋白表达水平（0.58±0.04、0.55±0.05比0.36±0.03）降低,E-cadherin蛋白的表达水平（0.22±0.02、0.25±0.03比0.47±0.03）增高,迁移细胞数（85.75±5.45、83.52±6.85比53.05±4.50）和侵袭细胞数（128.26±6.15、125.95±8.05比71.64±5.75）降低,差异有统计学意义（P均< 0.05）。与模拟物对照组比较,模拟物组细胞中Vimentin蛋白的表达水平（0.55±0.05比0.36±0.03）降低,而E-cadherin蛋白表达水平（0.25±0.03比0.47±0.03）升高,迁移细胞数（83.52±6.85比53.05±4.50）和侵袭细胞数（125.95±8.05比71.64±5.75）均减少（P均< 0.05）。TWIST1是miR-363-3p潜在的靶基因。与模拟物+ pcDNA3.1组比较,模拟物+ TWIST1组A549细胞中Vimentin蛋白的表达水平（0.32±0.02比0.42±0.03）升高,而E-cadherin蛋白表达水平（0.56±0.04比0.38±0.03）降低,A549细胞的迁移数（49.45±4.22比67.52±5.05）和侵袭数（72.45±5.73比108.35±6.56）增加（P均< 0.05）。 结论miR-363-3p可通过靶向TWIST1调控EMT抑制A549细胞迁移和侵袭。     

Cancer-associated fibroblasts promote epithelial-mesenchymal transition and EGFR-TKI resistance of non-small cell lung cancers via HGF/IGF-1/ANXA2 signaling

The involvement of the tumor stromal cells in acquired resistance of non-small cell lung cancers (NSCLCs) to tyrosine kinase inhibitors (TKIs) has previously been reported, but the precise mechanism remains unclear. In the present study, we investigated the role and mechanism underlying Cancer-associated fibroblasts (CAFs) in TKI resistance of NSCLCs. In vitro and in vivo experiments showed that HCC827 and PC9 cells, non-small cell lung cancer cells with EGFR-activating mutations, became resistant to the EGFR-TKI gefitinib when cultured with CAFs isolated from NSCLC tissues. Moreover, we showed that CAFs could induce epithelial-mesenchymal transition (EMT) phenotype of HCC827 and PC9 cells, with an associated change in the expression of epithelial to mesenchymal transition markers. Using proteomics-based method, we identified that CAFs significantly increased the expression of the Annexin A2 (ANXA2). More importantly, knockdown of ANXA2 completely reversed EMT phenotype and gefitinib resistance induced by CAFs. Furthermore, we found that CAFs increased the expression and phosphorylation of ANXA2 by secretion of growth factors HGF and IGF-1 and by activation of the corresponding receptors c-met and IGF-1R. Dual inhibition of HGF/c-met and IGF-1/IGF-1R pathways could significantly suppress ANXA2, and markedly reduced CAFs-induced EMT and gefitinib resistance. Taken together, these findings indicate that CAFs promote EGFR-TKIs resistance through HGF/IGF-1/ANXA2/EMT signaling and may be an ideal therapeutic target in NSCLCs with EGFR-activating mutations.     

Characterization of E-cadherin-dependent and -independent events in a new model of c-Fos-mediated epithelial-mesenchymal transition

Fos proteins have been implicated in control of tumorigenesis-related genetic programs including invasion, angiogenesis, cell proliferation and apoptosis. In this study, we demonstrate that c-Fos is able to induce mesenchymal transition in murine tumorigenic epithelial cell lines. Expression of c-Fos in MT1TC1 cells led to prominent alterations in cell morphology, increased expression of mesenchymal markers, vimentin and S100A4, DNA methylation-dependent down-regulation of E-cadherin and abrogation of cell-cell adhesion. In addition, c-Fos induced a strong beta-catenin-independent proliferative response in MT1TC1 cells and stimulated cell motility, invasion and adhesion to different extracellular matrix proteins. To explore whether loss of E-cadherin plays a role in c-Fos-mediated mesenchymal transition, we expressed wild-type E-cadherin and two different E-cadherin mutants in MT1TC1/c-fos cells. Expression of wild-type E-cadherin restored epithelioid morphology and enhanced cellular levels of catenins. However, exogenous E-cadherin did not influence expression of c-Fos-dependent genes, only partly suppressed growth of MT1TC1/c-fos cells and produced no effect on c-Fos-stimulated cell motility and invasion in matrigel. On the other hand, re-expression of E-cadherin specifically negated c-Fos-induced adhesion to collagen type I, but not to laminin or fibronectin. Of interest, mutant E-cadherin which lacks the ability to form functional adhesive complexes had an opposite, potentiating effect on cell adhesion to collagen I. These data suggest that cell adhesion to collagen I is regulated by the functional state of E-cadherin. Overall, our data demonstrate that, with the exception of adhesion to collagen I, c-Fos is dominant over E-cadherin in relation to the aspects of mesenchymal transition assayed in this study.     

CFTR activation suppresses glioblastoma cell proliferation,migration and invasion

The aim of this study was to investigate the function of Cystic fibrosis transmembrane conductance regulator (CFTR) in human glioblastoma (GBM) cells. Data dining results of the Human Protein Atlas showed that low CFTR expression was associated with poor prognosis for GBM patients. We found that CFTR protein expression was lower in U87 and U251 GBM cells than that in normal humane astrocyte cells. CFTR activation significantly reduced GBM cell proliferation. In addition, CFTR activation significantly abrogated migration and invasion of GBM cells. Besides, CFTR activator Forskolin treatment markedly reduced MMP-2 protein expression. These effects of CFTR activation were significantly inhibited by CFTR inhibitor CFTRinh-172 pretreatment. Our findings suggested that JAK2/STAT3 signaling was involved in the anti-glioblastoma effects of CFTR activation. Moreover, CFTR overexpression in combination with Forskolin induced a synergistic anti-proliferative response in U87?cells. Overall, our findings demonstrated that CFTR activation suppressed GBM cell proliferation, migration and invasion likely through the inhibition of JAK2/STAT3 signaling.     

Overexpression of heat shock protein 70 inhibits epithelial-mesenchymal transition and cell migration induced by transforming growth factor-β in A549 cells

Heat shock protein 70 (HSP70) is a key member of the HSP family that contributes to a pre-cancerous environment; however, its role in lung cancer remains poorly understood. The present study used geranylgeranylacetone (GGA) to induce HSP70 expression, and transforming growth factor-β (TGF-β) was used to construct an epithelial-mesenchymal transition (EMT) model by stimulating A549 cells in vitro. Western Blot was performed to detect protein levels of NADPH oxidase 4 (NOX4) and the EMT-associated proteins E-cadherin and vimentin both before and after HSP70 expression. Cell morphological changes were observed, and the effect of HSP70 on cell migration ability was detected via the wound healing. The results demonstrated that GGA at 50 and 200 μmol/L could significantly induce HSP70 expression in A549 cells (P < 0.05). Furthermore, HSP70 induced by 200 μmol/L GGA significantly inhibited the changes of E-cadherin, vimentin, and cell morphology induced by TGF-β (P < 0.05), while HSP70 induced by 50 μmol/L GGA did not. The results of the wound healing assay indicated that 200 μmol/L GGA significantly inhibited A549 cell migration induced by TGF-β. Taken together, the results of the present study demonstrated that overexpression of HSP70 inhibited the TGF-β induced EMT process and changed the cell morphology and migratory ability induced by TGF-β in A549 cells.     

过表达DNALI1抑制低氧环境中鼻咽癌细胞株CNE-2z侵袭与迁移

目的探讨模拟肿瘤内低氧微环境下,动力蛋白轴突轻链中间体1 （DNALI1）对鼻咽癌细胞株CNE-2z增殖、迁移、侵袭和凋亡的影响。 方法R语言软件分析GEO数据库中鼻咽癌组织的3个数据集,分析其差异基因（DEGs）。低氧是肿瘤微环境基本特征,体外细胞研究均在低氧工作站（1﹪O₂）中进行,以模拟体内低氧微环境。将DNALI1过表达质粒和空载体质粒包装成慢病毒后感染CNE-2z细胞,构建DNALI1基因稳定过表达的CNE-2z细胞株。将CNE-2z细胞分别进行正常培养（空白对照,BC）,感染空载体慢病毒（阴性对照,NC）和感染过表达DNALI1慢病毒（过表达DNALI1,DNALI1-OE）。实时荧光定量聚合酶链式反应（RT-qPCR）和Western blot检测DNALI1 mRNA和蛋白表达水平;集落形成实验检测细胞增殖能力;Transwell实验检测细胞迁移和侵袭能力;流式细胞术检测细胞凋亡水平。多组间比较采用单因素方差分析,组间两两比较采用LSD-t检验。 结果生物信息学分析发现,与健康人鼻咽组织相比,鼻咽癌组织中DNALI1基因低表达。在低氧环境中,BC组与NC组细胞增殖、凋亡、迁移和侵袭比较,差异均无统计学意义;与BC组和NC组比较,DNALI1-OE组细胞增殖能力和凋亡水平比较,差异均无统计学意义（P均> 0.05）。与BC组和NC组比较,DNALI1-OE组细胞迁移能力[（198.67±3.22）,（199.00±3.00）比（75.00±7.55）个]和侵袭能力[（240.67±16.01）,（259.67±3.06）比（83.33±9.50）个]降低,差异具有统计学意义（P均< 0.001）。 结论低氧环境中,DNALI1过表达可抑制CNE-2z细胞侵袭与迁移能力,但对细胞增殖、凋亡无明显影响。     

Knockdown of LINC01116 inhibits cell migration and invasion in head and neck squamous cell carcinoma through epithelial-mesenchymal transition pathway

Long noncoding RNAs (lncRNAs) are linked to tumor development and progression. The aim of this study was to determine the prognostic significance and biological role of LINC01116 in head and neck squamous cell carcinoma (HNSCC). We identified 21 aberrantly expressed lncRNAs specific to HNSCC that were common in two microarray datasets. LINC01116 was highly overexpressed in HNSCC tissues and was correlated to shorter overall survival and relapse-free survival duration, as analyzed by the online Gene Expression Profiling Interactive Analysis platform. LINC01116 was also overexpressed in oral squamous cell carcinoma and nasopharyngeal carcinoma tissues, and LINC01116 silencing significantly inhibited the migration and invasion capacities of both cell lines by blocking the epithelial-mesenchymal transition process. In addition, 125 coexpressing genes were identified by circlncRNAnet, and were mainly located on human autosomes and enriched in transforming growth factor-β signaling pathway. These findings indicate that LINC01116 might be a potential therapeutic target for HNSCC.     

Long non-coding RNA LINC01215 promotes epithelial-mesenchymal transition and lymph node metastasis in epithelial ovarian cancer through RUNX3 promoter methylation

Epithelial ovarian cancer (EOC) still remains the most lethal gynaecological malignancy in women, despite the recent progress in the management, including surgery and chemotherapy. According to the microarray data of the {"type":"entrez-geo","attrs":{"text":"GSE18520","term_id":"18520"}}GSE18520 and {"type":"entrez-geo","attrs":{"text":"GSE54388","term_id":"54388"}}GSE54388 datasets, LINC01215 was identified as an upregulated long noncoding RNA (lncRNA) in EOC. Therefore, this study aimed to figure out the involvement of LINC01215 in the progression of EOC. RT-qPCR was conducted to select the EOC cell line with the highest expression of LINC01215. Methylation of RUNX3 was then examined in EOC cells by MS-PCR. Furthermore, the interaction between LINC01215 and methylation-related proteins was revealed according to the results of RIP and RNA pull down assays. Subsequently, the involvement of LINC01215 and RUNX3 in regulating biological behaviors of EOC cells was investigated. Finally, the effects of the ectopic expression of LINC01215 and RUNX3 on the tumor formation and lymph node metastasis (LNM) of EOC cells were assessed in the xenograft tumors of nude mice. Overexpressing LINC01215 contributed to downregulated levels of RUNX3, as demonstrated by the recruitment of methylation-related proteins. Silencing of LINC01215 elevated the expression of RUNX3, thus suppressing cell proliferation, migration, invasion and EMT and decreasing the expressions of MMP-2, MMP-9 and Vimentin, but increased the expression of E-cadherin. The tumor growth and LNM were suppressed by downregulated levels of LINC01215 through inducing the expression of RUNX3. Collectively, the down-regulating LINC01215 could upregulate the expression of RUNX3 by promoting its methylation, thus suppressing EOC cell proliferation, migration and invasion, EMT, tumor growth and LNM.     

CircATRNL1 increases acid-sensing ion channel 1 to advance epithelial-mesenchymal transition in endometriosis by binding to microRNA-103a-3p

Circular RNA ATRNL1 (circATRNL1) has been implicated in epithelial-mesenchymal transition (EMT) during endometriosis. Given the existing literature and our predictions through starBase in this research, it was assumed that circATRNL1 might orchestrate the microRNA (miR)? 103a-3p/acid-sensing ion channel 1 (ASIC1) axis to control EMT in endometriosis. To verify our hypothesis, we detect circATRNL1, miR-103a-3p, and ASIC1 expression in endometrial cancer cells (HEC-B, AN3-CA, KLE, HEC1-A, and Ishikawa). Ishikawa cells with the highest circATRNL1 level were selected as subjects, where circATRNL1, miR-103a-3p, or ASIC1 expression was knocked down. Scratch and Transwell assays were applied to assess cell migration and invasion, and CCK-8 and colony formation assays to detect cell proliferation. Western blot was used to measure E-cadherin, N-cadherin, Vimentin, and Slug expression to evaluate the EMT state. Furthermore, the binding of miR-103a-3p to circATRNL1 or ASIC1 was validated by luciferase reporter assay. CircATRNL1 and ASIC1 were upregulated but miR-103a-3p was downregulated in endometrial cancer cells. Mechanistically, circATRNL1 bound to miR-103a-3p to upregulate a target gene of miR-103a-3p, ASIC1. CircATRNL1 silencing contributed to the decline of proliferation, invasion, migration, and EMT in Ishikawa cells, while miR-103a-3p inhibitor reversed those changes. In addition, the EMT process was aggravated when miR-103a-3p was inhibited and this process was suppressed by silencing ASIC1 in the presence of downregulated miR-101a-3p. Our study supported that circATRNL1 might be a novel therapeutic candidate target for endometriosis treatment and provided unique insights into the molecular basis concerning the pathogenesis of endometriosis.