The effects of miR-429 on cell migration and invasion by targeting Slug in esophageal squamous cell carcinoma

Increasing evidence indicates that microRNAs may play important roles in tumor development and may take part in different processes in different cancers. miR-429 is known as a cancer suppressor or oncogene that is dysregulated in different malignancies, including esophageal squamous cell carcinoma (ESCC). However, the effect of miR-429 in ESCC has not been fully explored. The purpose of this study was to investigate the functions of miR-429 in ESCC. qRT-PCR assays were performed to detect miR-429 expression in ESCC tissues and cell lines. To assess the effects of miR-429 on ESCC cells, wound healing and transwell assays were used. Luciferase reporter and western blot assays were employed to determine whether Slug is a major target of miR-429.Our results showed that the expression levels of miR-429 in ESCC tissues and cells were lower than in normal esophageal epithelial tissues and cells. Furthermore, overexpression of endogenous miR-429 inhibited the migration and invasion of ESCC cell lines. In addition, Luciferase reporter and western blot assays provided evidence that miR-429 can bind to the 3′ untranslated regions of Slug to regulate its expression and that of downstream epithelial-to-mesenchymal transition (EMT) markers. We found that Slug serves as a major target of miR-429. miR-429 plays a vital role in ESCC progression and represents a new therapeutic target for ESCC.     

Notch信号通路可通过激活Slug调控骨肉瘤上皮-间质转化

目的 探究Notch信号通路对骨肉瘤上皮-间质转化的影响及其机制。方法 通过慢病毒转染技术转染骨肉瘤细胞，利用si-slug敲除Slug基因，采用免疫荧光染色技术、Western blot、qRT-PCR、相差显微镜、划痕实验和TranswellTM实验检测相应骨肉瘤细胞形态、侵袭、转移及上皮间质转化（EMT）情况。动物实验比较各组小鼠成瘤后体积、重量变化；采用qRT-PCR检测离体肿瘤组织中Slug和N-cadherin的表达。结果 成功得到Notch信号通路激活或抑制的骨肉瘤细胞，Notch信号通路激活组E-cadherin表达无明显变化，N-cadherin表达显著升高，骨肉瘤细胞长/短轴比率上调，Slug、Twist1表达上调，侵袭及转移能力增强。动物实验发现Notch信号通路激活可促进体内成瘤，离体骨肉瘤组织中Slug、N-cadherin阳性率增高。Slug被成功敲除后Notch信号激活组骨肉瘤细胞形态、侵袭及转移能力发生逆转。结论 Notch信号通路对骨肉瘤上皮-间质转化过程具有促进作用，其机制可能与激活Slug有关。     

Slug在胰腺癌中的表达及干扰Slug对胰腺癌转移的影响

目的 探讨Slug和E-CADHERIN(E-cadherin)表达与胰腺癌转移的关系以及干扰Slug转录因子对胰腺癌转移的影响.方法 采用免疫组化和RT-PCR技术分别检测36例胰腺癌组织中Slug、E-cadherin和mRNA表达.将肝脏高转移潜能的胰腺癌细胞株SW1990H4,分为3组:对照组、空载体质粒(shRNA-1)和转染干扰S1ug质粒(Slug-shRNA-1),观察Slug对E-cadherin mRNA表达的逆转作用,及对SW1990H4体外侵袭、运动的抑制作用.结果 胰腺癌组织中Slug高表达,而E-cadherin低表达.转移组胰腺癌组织中Slug蛋白和mRNA表达明显高于非转移组,差异分别有统计学意义(P＜0.05),而E-cadherin在转移组胰腺癌中无表达.PCR产物凝胶电泳结果显示,Slug mRNA在空白对照组SW1990H4中表达为0.985±0.016,E-cadherin mRNA表达为0.120±0.001.shRNA-1时转染48 h时,Slug mRNA的表达水平为0.973±0.014,E-cadherin mRNA表达水平分别0.160±0.001,与对照组比差异分别无统计学意义(P＞0.05).转染Slug-shRNA-1组瞬时转染48 h时,Slug mRNA的表达水平为0.554±0.011,E-cadherin mRNA表达水平为0.36±0.002,与对照组和shRNA-1组比差异分别有统计学意义(P＜0.05).SW1990H4稳定转染后,shRNA-1和Slug-shRNA-1组Slug mRNA表达水平分别为0.968±0.015,0.206±0.017,两组比较,差异有统计学意义(P＜0.05),而E-cadherin mRNA表达水平分别为0.18±0.002,0.727±0.006,两组比较,差异有统计学意义(P＜0.05).体外细胞运动实验表明,对照组、转染shRNA-1和SlugshRNA-1组跨膜细胞数393±28、352±24、96±13,差异有统计学意义(P＜0.01).重组细胞基底膜(Matrige1)侵袭实验显示,3组穿透基底膜细胞数分别为223±69、202±64、65±19,差异有统计学意义(P＜0.05).结论 Slug高表达,E-cadherin低表达与胰腺癌的转移相关.胰腺癌细胞中存在Slug mRNA与E-cadherin mRNA表达的逆转关系,抑制Slug mRNA的表达对胰腺癌细胞的侵袭和运动有抑制作用,可能为胰腺癌转移的基因治疗提供新的靶点.

Abstract：

Objective To investigate expression of slug and E-cadherin in pancreatic cancer tissues and determine the inhibitory effects of anti-Slug, an anti-sense plasmid, on the invasion of pancreatic cancer cell lines in vitro. Methods Slug and E-cadherin protein and mRNA was analyzed by IHP and RT-PCR in 36 cases of pancreatic cancer. Then anti-Slug plasmid was transfected into herin and Slug expression. The inhibitory effects of anti-sense Slug were also detected by Transwell motility assay and Matrigel invasion assay. Results The expression of Slug and mRNA in metastatic pancreatic cancer tissue was higher than that in non-metastatic tissue. E-cadherin and mRNA was lower in metastasis tissues(P＜0.05). The inverse relationships were further observed by transient transfection of anti-Slug into SW1990H4 cells. The downregulated expression of Slug and re-expression of E-cadherin were found. The Slug mRNA levels were 0.985±0.016,0.973±0.014, 0. 554±0. 011 after 0, 48 h of transfection of anti-sense Slug, and that of E-cadherin were 0.120±0.001, 0.360±0.002, 0. 727±0. 006, respectively. The diference was significant between different time points (P＜0.05). The Slug mRNA levels were 0. 206±0.017, 0.968±0.015, and that of E-cadherin were 0. 18±0.002,0.727±0.006 after stable transfection of anti-sense Slug, and control plasmid, respectively. The diference was significant (P＜0.05). The motility activity(393±28, 352±24, 96 ±13 )and the invasion activity (223 ± 69, 202 ± 64, 65 ±19) of1 antisense Slug transfectant cells were significantly decreased as compared with those of control cells (P＜0.05). Conclusions Higher expression of slug and lower expression of E-cadherin is related to the invasion and metastasis in pancreatic cancer. A reverse corelation of E-cadherin and Slug expression exists in pancreatic cancer. Slug is possibly a potential target for cancer gene therapy blocking invasion and metastasis in human pancreatic cancer.     

上皮-间充质转分化与转录因子Snail、Slug、Twist在口腔鳞状细胞癌发生、发展中的作用

上皮-间充质转分化(EMT)是上皮细胞在特定生理和病理情况下向间充质细胞转化的现象,它在上皮性肿瘤的演进中发挥了关键作用。肿瘤发生过程中,转录因子Snail、Slug、Twist等常可引发EMT,促使肿瘤的侵袭与转移。Snail、Slug和Twist在口腔鳞癌演变过程中,尤其在浸润和转移中发挥重要作用。该文介绍EMT的概念、特征以及Snail、Slug和Twist的基因结构特点、生物学特性等,特别对其在口腔鳞癌中的作用进行了综述。     

S100A4 regulates motility and invasiveness of human esophageal squamous cell carcinoma through modulating the AKT/Slug signal pathway

The involvement of S100A4 in modulating invasiveness of esophageal squamous cell carcinoma (ESCC) cell lines was explored. It was shown that S100A4 expression is positively correlated with the degree of invasiveness in human ESCC cells. The S100A4‐rich EC‐1 cells displayed higher migratory and invasive cell behavior while ET‐1 cells with low S100A4 expression levels displayed lower migratory and invasive cell behavior. S100A4 silencing by small interfering (siRNA) in EC‐1 cells induced E‐cadherin expression, and overexpression of S100A4 in a lowly invasive TE‐1 cells suppressed E‐cadherin expression. It is suggested that S100A4 silencing inhibit invasion via E‐cadherin upregulation, and overexpression of S100A4 promote invasion via E‐cadherin downregulation in ESCC cells. Compared with the vector‐transfected cells, S100A4 silencing in EC‐1 cells showed reduced ability of migration and invasiveness, and overexpression of S100A4 in TE‐1 cells showed increased ability of migration and invasiveness via wound‐healing and Transwell assay, and pseudometastatic model assay. Furthermore, re‐expression of S100A4 could increase the invasive phenotypes in S100A4 siRNA transfected EC‐1 cells, and S100A4 silencing could decrease the invasive phenotypes in S100A4 circular DNA (cDNA) transfected TE‐1 cells. It was found that Slug is downregulated in S100A4 siRNA transfected EC‐1 cells, and Slug is upregulated in S100A4 cDNA transfected TE‐1 cells. It was also discovered S100A4 cDNA induced protein kinase B (AKT) phosphorylation at Serine‐473(phospho‐AKT [p‐AKT]) levels, followed by the Slug upregulation, and S100A4 siRNA decreases the phospho‐AKT levels, followed by the Slug downregulation. The data suggested that S100A4 could regulate migratory and invasive behavior of human ESCC cells through modulating AKT/Slug pathway.