Placenta growth factor promotes migration through regulating epithelial-mesenchymal transition-related protein expression in cervical cancer

Epithelial-mesenchymal transition (EMT) plays an important role in cancer invasion and metastasis by enabling cancer cells to depart from the primary tumor, invade surrounding tissue and disseminate to distant organs. The existence and function of EMT in cervical cancer is poorly understood. Placental growth factor (PLGF) has been shown to associate with EMT in various cancers. However, whether PLGF is involved in EMT in cervical cancer remains unclear. Thus the present study examined the relationship between PLGF expression and EMT-related proteins in 110 cervical lesions samples. We detected that PLGF was expressed in 61.8% cervical lesion sections. In addition, PLGF expression is positively correlated with low expression level of E-cadherin and high expression level of vimentin. Serum samples and cervical lavage samples were collected from patients with pre-invasive and invasive lesion of uterine cervix or normal control group, the PLGF levels were determined by enzyme-linked immunosorbent assay (ELISA). We found that a significantly high level of PLGF could be detected both in serum and vaginal lavage compared with normal women group, and there is no significant difference between serum and lavage in PLGF level. In addition, whatever in lavage or in serum, the PLGF level in stage I and II was significantly higher than it in CINIII or cancer in situ. However, there is no significant difference between the stage I and stage II; we also found that exogenous PLGF promotes molecular changes of epithelial-mesenchymal transition (EMT) in siha cells. In addition, application of a specific EKR1/2 inhibitor could reverse the effects of PLGF. These findings suggested that PLGF could regulate the expression of EMT-related proteins and promote migration of siha cells through ERK/MAPK signaling pathway. Therapies that targets PLGF/Flt-1/ERK/MAPK signaling pathway may be beneficial in treatment of cervical cancer.     

转录因子Runx2对人乳腺癌MDA-MB-231细胞上皮-间充质转化能力的影响

目的:建立稳定敲减Runt相关转录因子2(Runx2)表达的人乳腺癌MDA-MB-231细胞系,探讨Runx2对MDA-MB-231细胞上皮-间充质转化(EMT)、转移和侵袭能力的影响。方法:利用LV-Runx2-RNAi慢病毒载体感染MDA-MB-231细胞,构建稳定低表达Runx2的MDA-MB-231细胞株,检测比较Runx2表达水平对MDA-MB-231细胞的形态及E-cadherin、N-cadherin、β-catenin和基质金属蛋白酶9(MMP-9)蛋白表达的影响。侵袭实验和软琼脂集落形成实验分析比较抑制Runx2表达对乳腺癌细胞侵袭和非锚定生长能力的效应。结果:E-cadherin蛋白表达在敲减Runx2表达的MDA-MB-231细胞中明显高于常规MDA-MB-231细胞(P0.05),而N-cadherin、β-catenin和MMP-9蛋白表达在敲减Runx2表达的MDA-MB-231细胞中明显低于常规MDA-MB-231细胞(P0.05)。敲减Runx2表达的MDA-MB-231细胞侵袭和非锚定生长能力明显低于常规MDA-MB-231细胞(P0.05)。结论:在人乳腺癌MDA-MB-231细胞中抑制Runx2表达可以通过调控EMT相关蛋白的表达进而抑制乳腺癌细胞的EMT过程,从而对细胞的侵袭和转移起负调控作用。     

Synergistic activation of genes promoting invasiveness by dual deprivation in oxygen and nutrients

By depriving cancer cells of blood supplies of oxygen and nutrients, anti-angiogenic therapy is aimed at simultaneously asphyxiating and starving the cells. But in spite of its apparent logic, this strategy is generally counterproductive over the long term as the treatment seems to elicit malignancy. Since a defect of blood supply is expected to deprive tumours simultaneously of oxygen and nutrients naturally, we examine here these two deprivations, alone or in combination, on the phenotype and signalling pathways of moderately aggressive MCF7 cancer cells. Each deprivation induces some aspects of the aggressive and migratory phenotypes through activating several pathways, including HIF1-alpha as expected, but also SRF/MRTFA and TCF4/beta-catenin. Strikingly, the dual deprivation has strong cooperative effects on the upregulation of genes increasing the metastatic potential, such as four and a half LIM domains 2 (FHL2) and HIF1A-AS2 lncRNA, which have response elements for both pathways. Using anti-angiogenic agents as monotherapy is therefore questionable as it may give falsely promising short-term tumour regression, but could ultimately exacerbate aggressive phenotypes.     

MicroRNA-9通过NRP1抑制胃癌SGC-7901细胞上皮-间充质转化功能

目的:研究微小RNA-9(microRNA-9,miR-9)对胃癌SGC-7901细胞上皮-间充质转化(EMT)功能的影响及其相关机制。方法:SGC-7901胃癌细胞株分别转染miR-9 mimics和阴性对照序列(negative control mimic,NCM),作为miR-9组和NCM组,并设立未转染对照(control)组,采用RT-qPCR法检测各组细胞miR-9的含量,Transwell实验检测3组细胞迁移能力和侵袭能力,Western blot法检测3组细胞的N-cadherin、E-cadherin、α-catenin和神经纤毛蛋白1(NRP1)表达水平。采用Western blot法检测NRP1过表达对miR-9抑制EMT的拮抗作用。双萤光素酶实验检测miR-9与NRP1的关系。结果:miR-9组的miR-9表达水平明显上调,为control组的538倍(P0.05)。miR-9组的迁移细胞数量明显低于control组(P0.05)。miR-9组的侵袭细胞数量明显低于control组(P0.05)。miR-9组细胞的N-cadherin和NRP1蛋白表达量明显降低,E-cadherin及α-catenin蛋白表达量明显升高。而NRP1及miR-9均过表达组胃癌细胞中N-cadherin蛋白表达量明显升高,E-cadherin及α-catenin蛋白表达量明显降低。双萤光素酶检验结果显示NRP1为miR-9的下游靶基因(P0.05)。结论:miR-9可能通过降低下游靶基因NRP1水平影响EMT相关蛋白表达,抑制胃癌SGC-7901细胞的EMT功能。     

Snail plays an oncogenic role in glioblastoma by promoting epithelial mesenchymal transition

Background: The factors affecting glioblastoma progression are of great clinical importance since dismal outcomes have been observed for glioblastoma patients. The Snail gene is known to coordinate the regulation of tumor progression in diverse tumors through induction of epithelial mesenchymal transition (EMT); however, its role in glioblastoma is still uncertain. Therefore, we aimed to further define its role in vitro. Methods and results: The small interfering RNA (siRNA) technique was employed to knock down Snail expression in three glioblastoma cell lines (KNS42, U87, and U373). Specific inhibition of Snail expression increased E-cadherin expression but decreased vimentin expression in all cell lines. In addition, inhibition of the expression of Snail significantly reduced the proliferation, viability, invasion, and migration of glioblastoma cells as well as increased the number of cells in the G1 phase. Conclusions: Knockdown of Snail suppresses the proliferation, viability, migration, and invasion of cells as well as inhibits cell cycle progression by promoting EMT induction. The findings suggest that expression of this gene facilitates glioblastoma progression. Therefore, these results indicate the clinical significance of Snail for use as a potential therapeutic target for glioblastoma.     

同期放化疗诱导人结直肠癌细胞发生上皮-间质转化

目的:探讨放化疗抵抗的结直肠癌细胞发生上皮-间质转化(epithelial-mesenchymal transition,EMT)的意义.方法:采用5-FU化疗同期进行放疗对人结直肠癌野生型细胞(HCTll6)进行干预,诱导放化疗共同抵抗的细胞株(HCT1 16CRR)并采用克隆形成实验进行放化疗抵抗性的鉴定.高倍显微镜下观察细胞形态学变化.采用Real-time PCR和Western印迹,检测上皮表型标志物E-cadherin,间质表型标志物N-cadherin、波形蛋白(vimentin)、核转录因子(Snail)mRNA及其蛋白的表达.结果:放化疗抵抗的结直肠癌细胞发生与EMT相符的形态学改变,细胞呈纺锤体状,极性消失,并出现伪足;Real-time PCR和Western印迹结果显示E-cadherin mRNA及蛋白表达下调;N-cadherin,vimentin,Snail mRNA及蛋白表达上调,差异有统计学意义(P＜0.05).结论:放化疗抵抗后的人结直肠癌细胞发生EMT,其与结直肠癌的治疗抵抗相关.     

Targeting the Twist and Wnt signaling pathways in metastatic breast cancer

Breast cancer is the leading cause of cancer-related deaths in the United States with over 232,000 new diagnoses expected in 2014 and almost 40,000 deaths. While treatment of primary breast cancer is often well-managed with surgery and radiation, metastatic breast cancer (MBC) that has spread to the brain, bones, liver, and lungs is often incurable. One of the major challenges in the treatment of breast cancer is the presence of a subpopulation of cancer cells that are chemoresistant and metastatic. Given that metastasis is the driving force behind mortality for breast cancer patients, it is essential to identify the characteristics of these aberrant cancer cells that allow them to spread to distant sites in the body and develop into metastatic tumors. Understanding the metastatic mechanisms driving cancer cell dispersal will open the door to developing novel therapies that prevent metastasis and improve long-term outcomes for patients. In this review we assess the feasibility of targeting the Twist and Wnt signaling pathways in breast cancer. These pathways mediate epithelial-mesenchymal transition (EMT), a process that can give rise to chemoresistance. We review potential treatment strategies for targeting EMT and drug resistance as well as the problems that may arise with these targeted delivery therapeutic approaches. Finally, we examine recent advances in the field, including nanoparticle delivery and small interfering RNA (siRNA) technology, and discuss the impact that these approaches may have on translating much needed therapeutic approaches into the clinic, for the benefit of patients battling MBC.     

SDF-1α/CXCR4轴通过诱导胰腺癌上皮-间充质转化促进肿瘤迁移和侵袭

目的:探讨SDF-1α/CXCR4轴对胰腺癌细胞迁移和侵袭能力的影响及其作用机制。方法:应用RT-qPCR检测4种胰腺癌细胞株CXCR4 mRNA的表达。Transwell实验检测外源性SDF-1α及其受体CXCR4靶向抑制剂AMD3100对胰腺癌细胞迁移和侵袭能力的影响。MTS法检测外源性SDF-1α及AMD3100对胰腺癌细胞活力的影响。Western blot法检测外源性SDF-1α及AMD3100对胰腺癌细胞上皮-间充质转化(EMT)相关标志物表达的影响。结果:(1) 4种胰腺癌细胞株均不同程度地表达CXCR4 mRNA,其中PANC-1细胞株表达量最高。(2)外源性SDF-1α可增强PANC-1细胞的迁移和侵袭能力,该作用可被AMD3100所阻断。(3)外源性SDF-1α处理PANC-1细胞72 h可增强细胞活力,该作用可被AMD3100阻断。(4)外源性SDF-1α通过上调SNAIL和TWIST促使PANC-1细胞发生EMT,该作用可被AMD3100所阻断。结论:SDF-1/CXCR4轴通过促进胰腺癌细胞发生EMT而促进肿瘤迁移和侵袭。     

转录因子HOXA5在乳腺癌细胞中的下游信号通路

目的 探究转录因子HOXA5在乳腺癌进展中的作用。方法 构建过表达HOXA5的稳定转染BT549和SUM159细胞系, 在稳转BT549细胞系中利用Transwell检测细胞的转移能力;Western blotting检测上皮-间质转化（EMT）相关蛋白表达水平的变化;平板克隆实验检测细胞的增殖能力;转录组测序技术（RNA-seq）进一步分析HOXA5的调控基因,利用软件Cluster 3.0,Tree View和DAVID生物信息数据库（DAVID Bioinformatics Resources）以及Enrichr分析京都基因与基因组百科全书（KEGG）信号通路,绘制热图（heatmap）。 结果 BT549细胞系中,稳定转染HOXA5后的实验组细胞迁移能力显著降低(P<0.001),且上皮标志物 E-cadherin蛋白表达水平显著上调,间质标志物 N-cadherin, Twist1、Slug蛋白表达水平显著下调;平板克隆结果表明,实验组形成的克隆数目明显减少(P<0.05),克隆大小明显降低。 结论 HOXA5通过促进细胞由间质向上皮转化,抑制乳腺癌细胞迁移,并且抑制细胞增殖;HOXA5通过调节糖脂代谢途径调节癌细胞增殖,并且还通过调节细胞运动和黏附相关的基因抑制肿瘤细胞的迁移,通过肿瘤坏死因子（TNF）信号通路发挥抗肿瘤作用。总之,转录因子HOXA5对乳腺癌的发展和恶化起着显著的抑制作用。     

TUSC3 promotes colorectal cancer progression and epithelial–mesenchymal transition (EMT) through WNT/β‐catenin and MAPK signalling

Colorectal cancer (CRC) is one of the most common malignancies and is the second leading cause of cancer death in humans. Tumour suppressor candidate 3 (TUSC3) plays an important role in embryogenesis and metabolism. Deletion of TUSC3 often causes non‐syndromic mental retardation. Even though TUSC3 deregulation is frequently observed in epithelial cancers, the function of TUSC3 in CRC has remained unknown. In this study, we observed greater expression of TUSC3 at the mRNA and protein level in clinical colorectal tumour samples compared with paired normal tissues. Gain‐ and loss‐of‐function analyses were performed to evaluate the functional significance of TUSC3 in CRC initiation and progression. Immunoblotting, immunofluorescence, and co‐immunoprecipitation analyses were used to identify potential pathways with which TUSC3 might be involved. Overexpression of TUSC3 in CRC cells induced epithelial–mesenchymal transition (EMT) in CRC cells, accompanied by down‐regulation of the epithelial marker, E‐cadherin, and up‐regulation of the mesenchymal marker, vimentin. Increased proliferation, migration, and invasion, as well as accelerated xenograft tumour growth, were observed in TUSC3‐overexpressing CRC cells, while opposite effects were achieved in TUSC3‐silenced cells. In conclusion, our study demonstrated the oncogenic role of TUSC3 in CRC and showed that TUSC3 may be responsible for alternations in the proliferation ability, aggressiveness, and invasive/metastatic potential of CRC through regulating the MAPK, PI3K/Akt, and Wnt/β‐catenin signalling pathways. Copyright © 2016 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.     

Combination of epithelial-mesenchymal transition and cancer stem cell-like phenotypes has independent prognostic value in gastric cancer

Epithelial-mesenchymal transition-related proteins have been suggested to interact with each other in various cancers and be associated with the aggressive behavior of cancer. To demonstrate the clinical significance of epithelial-mesenchymal transition and stem cell-like phenotypes in gastric cancer, we performed immunohistochemistry for 5 epithelial-mesenchymal transition-related proteins, including Snail-1, ZEB-1, E-cadherin, vimentin, and β-catenin, and the gastric cancer stem cell marker CD44 in 276 consecutive primary gastric cancers and 54 matched lymph node metastases. Loss of E-cadherin expression and aberrant expression of vimentin were significantly associated with aggressive clinicopathologic features. The expression of epithelial-mesenchymal transition-related proteins was closely related to each other in gastric cancer. The known gastric cancer stem cell maker, CD44, was significantly associated with the protein expression of Snail-1, ZEB-1, and E-cadherin (P < .05). Univariate survival analysis was performed for the 6 proteins included in this study to find the best combination for predicting patient outcome. Protein expression of Snail-1, vimentin, E-cadherin, and CD44 resulted in the lowest P value using the Kaplan-Meier method (P < .001). This combination of proteins was significantly associated with advanced pT stage, lymph node metastasis, vascular invasion, and undifferentiated histologic type in a high-risk group (P < .001) and predicted disease-free survival independent of pTNM stage and histologic differentiation (P = .029). However, the acquired mesenchymal phenotype of gastric cancer cells at the primary site was restored to an epithelial phenotype in lymph node metastases. A combination of epithelial-mesenchymal transition and stem cell-like phenotypes is an important predictor of aggressive biologic behavior and has an independent prognostic value in predicting outcomes of primary gastric cancer.     

HMGA2在胃癌细胞上皮-间充质转化中的作用

目的:探讨HMGA2在胃癌细胞上皮-间充质转化(EMT)中的作用及机制。方法:采用Western blot和RT-qPCR实验检测不同分化程度的人胃癌细胞株MKN45、MKN28和SGC7901以及人永生化胃黏膜上皮细胞株GES-1中HMGA2的表达水平;采用脂质体转染法将pcDNA3.0-HMGA2质粒转染至MKN28细胞中,将si-HMGA2干扰片段转染至MKN45细胞中,并采用Western blot和RT-qPCR实验检测转染效率;CCK-8实验检测HMGA2上调对MKN28细胞活力的影响以及HMGA2下调对MKN45细胞活力的影响;采用细胞迁移和侵袭实验检测HMGA2上调对MKN28细胞迁移和侵袭能力的影响;采用Western blot和RT-qPCR实验检测HMGA2过表达对MKN28细胞EMT相关标志蛋白上皮型钙黏蛋白(E-cadherin)、神经型钙黏蛋白(N-cadherin)和波形蛋白(vimentin)表达的影响以及敲减HMGA2表达对MKN45细胞E-cadherin、N-cadherin和vimentin表达的影响;采用RT-qPCR实验检测过表达HMGA2的MKN28细胞Wnt/β-catenin信号通路相关分子表达的变化。结果:HMGA2在不同分化程度的胃癌细胞中的表达水平是不同的(P0.05)。上调MKN28细胞HMGA2的表达水平能够抑制细胞活力(P0.05);而在MKN45细胞中下调HMGA2的表达水平能够增强细胞活力(P0.05)。上调MKN28细胞HMGA2的表达水平能够促进细胞的迁移和侵袭能力(P0.05),且E-cadherin表达降低,N-cadherin和vimentin表达升高(P0.05);敲减HMGA2在MKN45细胞的表达水平使E-cadherin表达升高,而N-cadherin和vimentin表达降低(P0.05)。上调MKN28细胞中HMGA2的表达水平,细胞内Wnt/β-catenin通路的β-catenin及其下游分子c-Myc和cyclin D1的mRNA表达水平显著增加(P0.05)。结论:HMGA2与胃癌细胞迁移和侵袭能力密切相关,并且能够通过激活细胞内Wnt/β-catenin通路,促进胃癌细胞EMT。