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1.
This study aimed to investigate the role of fatty acid synthase (FASN) in the epithelial-mesenchymal transition (EMT) of breast cancer cells. MCF-7 cells and MCF-7 cells overexpressing mitogen-activated protein kinase 5 (MCF-7-MEK5) were used in this study. MCF-7-MEK5 cells showed stable EMT characterized by increased vimentin and decreased E-cadherin expression. An In vivo animal model was established using the orthotopic injection of MCF-7 or MCF-7-MEK5 cells. Real-time quantitative PCR and western blotting were used to detect the expression levels of FASN and its downstream proteins liver fatty acid-binding protein (L-FABP) and VEGF/VEGFR-2 in both in vitro and in vivo models (nude mouse tumor tissues). In MCF-7-MEK5 cells, significantly increased expression of FASN was associated with increased levels of L-FABP and VEGF/VEGFR-2. Cerulenin inhibited MCF-7-MEK5 cell migration and EMT, and reduced FASN expression and down-stream proteins L-FABP, VEGF, and VEGFR-2. MCF-7-MEK5 cells showed higher sensitivity to Cerulenin than MCF-7 cells. Immunofluorescence revealed an increase of co-localization of FASN with VEGF on the cell membrane and with L-FABP within MCF-7-MEK5 cells. Immunohistochemistry further showed that increased percentage of FASN-positive cells in the tumor tissue was associated with increased percentages of L-FABP- and VEGF-positive cells and the Cerulenin treatment could reverse the effect. Altogether, our results suggest that FASN is essential to EMT possibly through regulating L-FABP, VEGF and VEGFR-2. This study provides a theoretical basis and potential strategy for effective suppression of malignant cells with EMT.  相似文献   

2.
Treatments for triple-negative breast cancer (TNBC) are limited; intermediate-conductance calcium-activated potassium (SK4) channels are closely involved in tumor progression, but little is known about these channels in TNBC. We aimed to investigate whether SK4 channels affect TNBC. First, by immunohistochemistry (IHC) and western blotting (WB), increased SK4 protein expression in breast tumor tissues was detected relative to that in non-tumor breast tissues, but there was no apparent expression difference between various subtypes of breast cancer (p>0.05). Next, functional SK4 channels were detected in the TNBC cell line MDA-MB-231 using WB, real-time PCR, immunofluorescence and patch-clamp recording. By employing SK4 specific siRNAs and blockers, including TRAM-34 and clotrimazole, in combination with an MTT assay, a colony-formation assay, flow cytometry and a cell motility assay, we found that the suppression of SK4 channels significantly inhibited cell proliferation and migration and promoted apoptosis in MDA-MB-231 cells (p<0.05). Further investigation revealed that treatment with epidermal growth factor (EGF)/basic fibroblast growth factor (bFGF) caused MDA-MB-231 cells to undergo the epithelial-mesenchymal transition (EMT) and to show increased SK4 mRNA expression. In addition, the down-regulation of SK4 expression inhibited the EMT markers Vimentin and Snail1. Collectively, our findings suggest that SK4 channels are expressed in TNBC and are involved in the proliferation, apoptosis, migration and EMT processes of TNBC cells.  相似文献   

3.
We sought to find the biological effects of MicroRNA-2 in suppressing Lewis lung cancer cells proliferation, invasion, and migration in tumor-bearing mice. MicroRNA-2 was transfected into Lewis lung cancer cells of tumor-bearing mice by gene transient transfection technique and these Lewis-microRNA-2 cells were taken as MicroRNA transfection group. At the same time, Lewis cells were taken as control group and Lewis-EGFP cells as empty plasmid group. The growth curves of cells in the three groups were drawn by manual counting method, while the invasiveness of cells in the three groups was compared by transmembrane cell invasion assay. The three kinds of cells were seeded into BALB/Nude SPF level nude mice to detect the formation of tumors and the number of metastases by Xenograft experiments. The result showed that the MicroRNA transfection group has the lowest vitality of cells proliferation, fewest cells passed through matrigel matrix protein layer, and lowest cells invasive rate. Mice with Lewis-microRNA-2 cells apparently had a longer time of tumor formation. The average tumor mass and the number of metastases were significantly lower than the other two groups. MicroRNA-2 significantly inhibited Lewis lung cancer cell proliferation, invasion and migration in tumor-bearing mice, which may be associated with the regulation of target genes PLK1 and TGF-β.  相似文献   

4.
Obesity has been implicated as a significant risk factor for development of pancreatic cancer. In the setting of obesity, a systemic chronic inflammatory response is characterized by alterations in the production and secretion of a wide variety of growth factors. Leptin is a hormone whose level increases drastically in the serum of obese patients. High fat diet induced obesity in mice leads to an overall increased body weight, pancreatic weight, serum leptin, and pancreatic tissue leptin levels. Here we report the contribution of obesity and leptin to pancreatic cancer growth utilizing an in vivo orthotopic murine pancreatic cancer model, which resulted in increased tumor proliferation with concomitant increased tumor burden in the diet induced obese mice compared to lean mice. Human and murine pancreatic cancer cell lines were found to express the short as well as the long form of the leptin receptor and functionally responded to leptin induced activation through an increased phosphorylation of AKT473. In vitro, leptin stimulation increased cellular migration which was blocked by addition of a PI3K inhibitor. In vivo, depletion of the leptin receptor through shRNA knockdown partially abrogated increased orthotopic tumor growth in obese mice. These findings suggest that leptin contributes to pancreatic tumor growth through activation of the PI3K/AKT pathway, which promotes pancreatic tumor cell migration.  相似文献   

5.
CHIP, a co-chaperone protein that interacts with Hsc/Hsp70, has been shown to be under-expressed in pancreatic cancer cells and has demonstrated a potential tumor suppressor property. Nevertheless, the underlying mechanisms of CHIP regulation in pancreatic cancer cells remain unknown. In this study, we found that miR-1178 decreased the translation of the CHIP protein by targeting the 3′-UTR region. We observed that over-expression of miR-1178 facilitated the proliferation, G1/S transition, migration and invasion of pancreatic cancer cells. Conversely, the inhibition of miR-1178 expression significantly suppressed these phenotypes. Furthermore, CHIP over-expression abrogated miR-1178-induced cell proliferation and invasion. Our data suggest that miR-1178 acts as an oncomiR in pancreatic cancer cells by inhibiting CHIP expression.  相似文献   

6.
Radiotherapy is a widely used treatment for cancer. However, recent studies suggest that ionizing radiation (IR) can promote tumor invasion and metastasis. Bmi-1, a member of the polycomb group protein family, has been observed as a regulator of oxidative stress and promotes metastasis in some tumors. But, its potential role in the metastasis induced by IR of breast cancer has not been explored. In our study, we found that increased levels of Bmi-1 were correlated to EMT of breast cancer cells. Through analyzing the EMT state and metastasis of breast cancer induced by IR, we found the metastatic potential of breast cancer cells can either be inhibited or accelerated by IR following a time-dependent pattern. Silencing Bmi-1 completely abolished the ability of the IR to alter, reduce or increase, the migration of breast cancer cells. Also, when Bmi-1 was knocked down, the effect of inhibition of PI3K/AKT signaling on EMT affected by IR was blocked. These results suggest that Bmi-1 is a key gene in regulation of EMT and migration of breast cancer cells induced by IR through activation of PI3K/AKT signaling; therefore, Bmi-1 could be a new target for inhibiting metastasis caused by IR.  相似文献   

7.
We report cell mechanical changes in response to alteration of expression of the human equilibrative nucleoside transporter-1 (hENT1), a most abundant and widely distributed plasma membrane nucleoside transporter in human cells and/or tissues. Modulation of hENT1 expression level altered the stiffness of pancreatic cancer Capan-1 and Panc 03.27 cells, which was analyzed by atomic force microscopy (AFM) and correlated to microfluidic platform. The hENT1 knockdown induced reduction of cellular stiffness in both of cells up to 70%. In addition, cellular phenotypic changes such as cell morphology, migration, and expression level of epithelial-mesenchymal transition (EMT) markers were observed after hENT1 knockdown. Cells with suppressed hENT1 became elongated, migrated faster, and had reduced E-cadherin and elevated N-cadherin compared to parental cells which are consistent with epithelial-mesenchymal transition (EMT). Those cellular phenotypic changes closely correlated with changes in cellular stiffness. This study suggests that hENT1 expression level affects cellular phenotype and cell elastic behavior can be a physical biomarker for quantify hENT1 expression and detect phenotypic shift. Furthermore, cell mechanics can be a critical tool in detecting disease progression and response to therapy.  相似文献   

8.
为了研究白藜芦醇对人胰腺癌细胞增殖和存活的影响,利用不同浓度白藜芦醇处理PANC-1和Bx PC-3细胞,通过MTS和软琼脂集落实验检测白藜芦醇对胰腺癌细胞的停泊依赖和停泊非依赖增殖的抑制。同时,采用免疫印迹的方法,检测不同浓度白藜芦醇对胰腺癌细胞增殖相关信号通路的调控,及不同时间点凋亡激活相关蛋白分子的表达。结果发现白藜芦醇能剂量依赖性抑制PANC-1和Bx PC-3细胞增殖,并且这种增殖抑制作用与表皮生长因子受体(epithelial growth factor receptor,EGFR)及下游信号通路的抑制有关。一定浓度的白藜芦醇能诱导胰腺癌细胞发生凋亡,caspase3和caspase7被剪切活化。通过检测Bcl-2(B-cell lymphoma-2,Bcl-2)促存活家族蛋白,证实白藜芦醇能有效抑制Mcl-1(myeloid cell leukemia-1,Mcl-1)的表达,并不改变Bcl-2和Bcl-XL的表达。实验结果初步表明,白藜芦醇抑制胰腺癌的增殖与存活与EGFR信号通路及促存活蛋白Mcl-1的表达下调有关。  相似文献   

9.

Background

Adrenomedullin (AM) is highly expressed in pancreatic cancer and stimulates pancreatic cancer cells leading to increased tumor growth and metastasis. The current study examines the role of specific AM receptors on tumor and cells resembling the tumor microenvironment (human pancreatic stellate - HPSC, human umbilical vein – HUVEC and mouse lung endothelial cells - MLEC).

Methods and Findings

AM receptors ADMR and CRLR were present in HPSC, HUVEC and MLECs while PDAC cells possessed only ADMR receptors as assessed by RT-PCR and western blotting. All cell lines expressed and secreted AM as indicated by ELISA. The growth of each of the cell lines was stimulated by exogenous AM and inhibited by the antagonist AMA. AM also stimulated in vitro angiogenesis assessed by polygon formation of endothelial cell lines. SiRNA-mediated silencing of ADMR, but not CRLR, reduced basal growth of all cells examined and reduced polygon formation of endothelial cells in vitro. Orthotopic tumors developed with shADMR bearing cancer cells had dramatically reduced primary tumor volume (>90%) and lung and liver metastasis compared to shControl bearing cells. To validate ADMR as a potential therapeutic target, in vivo studies were conducted using neutral nanoliposomes to systemically deliver human siRNA to ADMR to silence human cancer cells and mouse siRNA to ADMR to silence mouse tumor stromal cells. Systemic silencing of both human and mouse ADMR had no obvious adverse effects but strongly reduced tumor development.

Conclusion

ADMR mediates the stimulatory effects of AM on cancer cells and on endothelial and stellate cells within the tumor microenvironment. These data support the further development of ADMR as a useful target treatment of pancreatic cancer.  相似文献   

10.

Background

In-vitro expansion of functional beta cells from adult human islets is an attractive approach for generating an abundant source of cells for beta-cell replacement therapy of diabetes. Using genetic cell-lineage tracing we have recently shown that beta cells cultured from adult human islets undergo rapid dedifferentiation and proliferate for up to 16 population doublings. These cells have raised interest as potential candidates for redifferentiation into functional insulin-producing cells. Previous work has associated dedifferentiation of cultured epithelial cells with epithelial-mesenchymal transition (EMT), and suggested that EMT generates cells with stem cell properties. Here we investigated the occurrence of EMT in these cultures and assessed their stem cell potential.

Methodology/Principal Findings

Using cell-lineage tracing we provide direct evidence for occurrence of EMT in cells originating from beta cells in cultures of adult human islet cells. These cells express multiple mesenchymal markers, as well as markers associated with mesenchymal stem cells (MSC). However, we do not find evidence for the ability of such cells, nor of cells in these cultures derived from a non-beta-cell origin, to significantly differentiate into mesodermal cell types.

Conclusions/Significance

These findings constitute the first demonstration based on genetic lineage-tracing of EMT in cultured adult primary human cells, and show that EMT does not induce multipotency in cells derived from human beta cells.  相似文献   

11.
Cinobufagin (CB), with its steroidal nucleus structure, is one of the major, biologically active components of Chan Su. Recent studies have shown that CB exerts inhibitory effects against numerous cancer cells. However, the effects of CB regarding the metastasis of non-small cell lung cancer (NSCLC) and the involved mechanisms need to be further studied. The purpose of the present study aimed to report the inhibitory function of CB against proliferation and metastasis of H1299 cells. CB inhibited proliferation of H1299 lung cancer cells with an IC50 value of 0.035±0.008 μM according to the results of MTT assays. Antiproliferative activity was also observed in colony forming cell assays. In addition, 5-ethynyl-2’-deoxyuridine (EdU) retention assays revealed that CB significantly inhibited the rate of DNA synthesis in H1299 cells. Moreover, results of the scratch wound healing assays and transwell migration assays displayed that CB exhibited significant inhibition against migration and invasion of H1299 cells. Furthermore, CB could concentration-dependently reduce the expression of integrin α2, β-catenin, FAK, Src, c-Myc, and STAT3 in H1299 cells. These western blotting results indicated that CB might target integrin α2, β-catenin, FAK and Src to suppress invasion and migration of NSCLC, which was consistent with the network pharmacology analysis results. Collectively, findings of the current study suggest that CB possesses promising activity against NSCLC growth and metastasis.  相似文献   

12.
肿瘤微环境是一个复杂的组织样结构,具有丰富的表型和功能异质性。不同浓度的趋化因子、细胞因子与组成肿瘤微环境的细胞间相互作用,可激活上皮–间质转化(epithelial-mesenchymal transition,EMT)相关的信号通路及控制肿瘤干细胞(cancer stem cells,CSCs)的生成。EMT的异常激活会促进肿瘤细胞的可塑性,赋予上皮细胞间充质特性,并与癌细胞获得侵袭性的特征密切相关。CSCs是一类具有高致瘤潜能的细胞群,其能很容易地适应周围环境的变化,与肿瘤内其他细胞相比具有较强的抗药性。该文对肿瘤微环境中EMT与CSC的作用机制及相关信号通路的研究进展进行综述。  相似文献   

13.
Vascular endothelial growth factor receptor-1 (VEGFR-1 or Flt-1), a tyrosine kinase receptor, is highly expressed in breast cancer tissues, but near absent in normal breast tissue. While VEGFR-1 expression is associated with poor prognosis of women with breast cancer, it is not clear whether it is involved in the aggressiveness of breast cancer. Thus, the present study examined whether VEGFR-1 activation is associated with the invasiveness of breast cancer. We reported that VEGFR-1 was detected in 60.6% of invasive breast carcinoma tissue sections. In addition, VEGFR-1 expression positively correlated with lymph node-positive tumor status, low expression level of membranous E-cadherin, and high expression levels of N-cadherin and Snail. We found that PlGF-mediated VEGFR-1 activation promoted migration and invasion in MCF-7 (luminal) cells and led to morphologic and molecular changes of epithelial-mesenchymal transition (EMT). This was blocked by the down-regulation of VEGFR-1. Conversely, down-regulation of VEGFR-1 in MDA-MB-231 (post-EMT) cells resulted in morphologic and molecular changes similar to mesenchymal-epithelial transition (MET), and exogenous PlGF could not reverse these changes. Moreover, VEGFR-1 activation led to an increase in nuclear translocation of Snail. Finally, MDA-MB-231 cells expressing shRNA against VEGFR-1 significantly decreased the tumor growth and metastasis capacity in a xenograft model. Histological examination of VEGFR-1/shRNA-expressing tumor xenografts showed up-regulation of E-cadherin and down-regulation of N-cadherin and Snail. These findings suggest that VEGFR-1 may promote breast cancer progression and metastasis, and therapies that target VEGFR-1 may be beneficial in the treatment of breast cancer patients.  相似文献   

14.

Background

Increased levels of NF-κB are hallmarks of pancreatic ductal adenocarcinoma (PDAC) and both classical and alternative NF-κB activation pathways have been implicated.

Methodology/Principal Findings

Here we show that activation of the alternative pathway is a source for the high basal NF-κB activity in PDAC cell lines. Increased activity of the p52/RelB NF-κB complex is mediated through stabilization and activation of NF-κB-inducing kinase (NIK). We identify proteasomal downregulation of TNF receptor-associated factor 2 (TRAF2) as a mechanism by which levels of active NIK are increased in PDAC cell lines. Such upregulation of NIK expression and activity levels relays to increased proliferation and anchorage-independent growth, but not migration or survival of PDAC cells.

Conclusions/Significance

Rapid growth is one characteristic of pancreatic cancer. Our data indicates that the TRAF2/NIK/NF-κB2 pathway regulates PDAC cell tumorigenicity and could be a valuable target for therapy of this cancer.  相似文献   

15.
16.
MicroRNAs can function as key tumor suppressors or oncogenes and act as biomarkers for cancer diagnosis or prognosis. Although high-throughput assays have revealed many miRNA biomarkers for pancreatic ductal adenocarcinoma (PDAC), only a few have been validated in independent populations or investigated for functional significance in PDAC pathogenesis. In this study, we correlated the expression of 36 potentially prognostic miRNAs within PDAC tissue with clinico-pathological features and survival in 151 Chinese patients. We then analyzed the functional roles and target genes of two miRNAs in PDAC development. We found that high expression of miR-186 and miR-326 predict poor and improved survival, respectively. miR-186 was over-expressed in PDAC patients compared with controls, especially in patients with large tumors (>2 cm), lymph node metastasis, or short-term survival (< 24 months). In contrast, miR-326 was down-regulated in patients compared with controls and displayed relatively increased expression in the patients with long-term survival or without venous invasion. Functional experiments revealed that PDAC cell proliferation and migration was decreased following inhibition and enhanced following over-expression of miR-186. In contrast, it was enhanced following inhibition and decreased after over-expression of miR-326. A luciferase assay indicated that miR-186 can bind directly to the 3′-UTR of NR5A2 to repress gene expression. These findings suggest that miR-186 over-expression contributes to the invasive potential of PDAC, likely via suppression of NR5A2, thereby leading to a poor prognosis; high miR-326 expression prolongs survival likely via the decreasing invasive potential of PDAC cells. These two miRNAs can be used as markers for clinical diagnosis and prognosis, and they represent therapeutic targets for PDAC.  相似文献   

17.
上皮-间充质转化(epithelial-mesenchymal transition, EMT)是上皮细胞来源的恶性肿瘤细胞获得迁移和侵袭能力的重要生物学过程。为了探究Krüppel样因子5 (Krüppel-like factor 5, KLF5)调控宫颈癌细胞发生EMT过程的分子机制,首先在宫颈癌HeLa细胞瞬时转染Flag-KLF5质粒进行KLF5过表达,并通过MTT法、细胞划痕和Transwell实验证实, KLF5可以显著地抑制HeLa细胞的侵袭和迁移能力。然后采用Western-blot和实时定量PCR技术检测HeLa细胞中EMT相关基因的表达水平,结果显示E-cadherin表达升高, N-cadherin和MMP9表达降低;而且, E-cadherin基因的上游调控因子如SNAI1、SLUG、ZEB1/2和TWIST1等的m RNA表达下降。进一步开展对比研究,在Si Ha细胞中用si RNA沉默KLF5基因,再次验证了KLF5对EMT相关基因表达水平的影响。随后构建不同长度的SNAI1启动子截短体,用荧光素酶报告基因实验检测KLF5对SNAI1启动子活性的影响,结果显示KLF5可以抑制SNAI1启动子区域的活性,并且在HeLa细胞中过表达SNAI1基因后,可显著地促进细胞的EMT过程。以上结果表明, KLF5可通过调控SNAI1基因的表达来调节宫颈癌细胞的EMT过程,进而抑制宫颈癌细胞的迁移和侵袭能力。  相似文献   

18.
胃癌患者转移淋巴结中胃泌素基因的表达量是原发胃癌组织的42倍,推测胃泌素可能与胃癌转移密切相关. 本文通过构建含胃泌素基因的真核表达载体,成功获得过表达胃泌素的稳转胃癌细胞株AGS和SGC-7901, 并用MTT、细胞伤愈实验、Transwell 小室实验及ELISA检测过表达胃泌素对细胞迁移、侵袭及转移相关蛋白基质金属蛋白酶2(MMP-2)分泌能力的影响. 结果显示,过表达胃泌素稳转细胞的相对增殖率、 迁移入细胞致伤区的相对距离比对照组高,迁移和侵袭到Transwell下室面的细胞, 以及培养液中每mg蛋白质的MMP-2浓度也高于对照组的细胞. 结果提示,胃泌素通过促进胃癌细胞分泌MMP-2来增强细胞的迁移和侵袭能力. 该研究对揭示胃癌转移的分子机制具有重要意义.  相似文献   

19.
Protein Tyrosine Kinase 6 (PTK6) is a non-receptor type tyrosine kinase that may be involved in some cancers. However, the biological role and expression status of PTK6 in pancreatic cancer is unknown. Therefore in this study, we evaluated the functional role of PTK6 on pancreatic cancer invasion. Five pancreatic cancer cell lines expressed PTK6 at varying levels. PTK6 expression was also observed in human pancreatic adenocarcinomas. PTK6 suppression by siRNA significantly reduced both cellular migration and invasion (0.59/0.49 fold for BxPC3, 0.61/0.62 for Panc1, 0.42/0.39 for MIAPaCa2, respectively, p<0.05 for each). In contrast, forced overexpression of PTK6 by transfection of a PTK6 expression vector in Panc1 and MIAPaCa2 cells increased cellular migration and invasion (1.57/1.67 fold for Panc1, 1.44/1.57 for MIAPaCa2, respectively, p<0.05). Silencing PTK6 reduced ERK1/2 activation, but not AKT or STAT3 activation, while PTK6 overexpression increased ERK1/2 activation. U0126, a specific inhibitor of ERK1/2, completely abolished the effect of PTK6 overexpression on cellular migration and invasion. These results suggest that PTK6 regulates cellular migration and invasion in pancreatic cancer via ERK signaling. PTK6 may be a novel therapeutic target for pancreatic cancer.  相似文献   

20.
目的:探讨长链非编码RNA SNHG3对人乳腺癌细胞MCF-7增殖、迁移与侵袭的影响。方法:构建SNHG3过表达质粒,实验分别设置阴性对照组(pcDNA-3.1+)与SNHG3基因过表达组(pcDNA-3.1+/SNHG3)。将MCF-7细胞转染对照组质粒和SNHG3过表达质粒,采用实时定量PCR 方法检测 SNHG3 mRNA 转录水平,Western blot 检测MMP9及EMT相关蛋白质水平;集落形成实验检测MCF-7细胞增殖能力;划痕愈合实验检测MCF-7细胞横向迁移能力; Transwell 小室实验检测MCF-7细胞纵向迁移能力及侵袭能力。结果:过表达SNHG3后,MCF-7细胞中SNHG3的mRNA水平显著增高(P<0.001);MCF-7细胞的体外增殖能力明显增加(P<0.01),迁移(P<0.01)与侵袭能力(P<0.001)也显著增强,实时定量PCR, Western blot 结果显示SNHG3可激活EMT相关通路。结论:过表达SNHG3可能通过激活EMT通路促进乳腺癌MCF-7细胞的增殖,迁移与侵袭。  相似文献   

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