S100A6通过PI3K/Akt信号通路促进人骨肉瘤细胞143B增殖和迁移

 目的：研究PI3K/Akt信号通路在S100A6介导的人骨肉瘤细胞143B的增殖和迁移中的作用。方法：首先制备重组的人S100A6蛋白（recombinant human S100A6, rhS100A6）;rhS100A6与PI3K抑制剂（LY294002和wortmannin）单独或同时处理143B细胞,其中rhS100A6的终浓度为30 mg/L,LY294002和wortmannin的终浓度分别为10 μmol/L和05 μmol/L;采用Western blotting分析143B细胞中PI3K/Akt信号通路相关分子总Akt（total Akt, t-Akt）及磷酸化Akt（phosphorylation of Akt, p-Akt）蛋白的表达变化,MTT检测细胞增殖,Transwell检测细胞迁移。 结果：（1）成功制备rhS100A6蛋白,rhS100A6显著增强143B细胞的增殖和迁移能力（P<005）;（2）rhS100A6上调143B细胞中Akt的磷酸化;（3）与rhS100A6组相比,rhS100A6与LY294002或wortmannin联合处理组143B细胞的p-Akt减少（P<005）,细胞的增殖和迁移能力降低,在不同时点细胞的增殖率下降103%～697%,细胞迁移率下降379%～416%,差异均有统计学意义（P<005）。 结论：S100A6促进人骨肉瘤细胞143B增殖和迁移的作用至少部分是通过激活PI3K/Akt信号通路实现的。     

胰岛素样生长因子2通过磷酯酰肌醇-3激酶/蛋白激酶B信号通路调控人卵巢颗粒细胞增殖的机制

目的 检测胰岛素样生长因子2（IGF2）对人卵巢颗粒细胞（KGN细胞）增殖的调控作用及作用机制。 方法 将体外培养的KGN细胞,分不同浓度IGF2处理组（对照组和25 μg/L、50 μg/L、100 μg/L IGF2组)和磷酯酰肌醇-3激酶/蛋白激酶B(PI3K/Akt)信号通路干预组（以LY294002干预处理将细胞分对照组、100μg/L IGF2组、LY294002组和IGF2+LY294002组）。采用MTS和5-乙炔基-2’-脱氧尿苷(EdU)法检测IGF2对KGN细胞增殖的影响,ELISA法检测细胞培养液上清中雌激素、孕激素的含量,Western blotting法检测各组胰岛素样生长因子受体1（IGF1R）、蛋白激酶B（Akt）、磷酸化的蛋白激酶B（p-Akt）及CYP19A1蛋白表达。 结果 随着IGF2的浓度梯度增高,KGN细胞的增殖率及雌激素、孕激素的分泌量逐渐升高,以 100 μg/L IGF2处理组的细胞增殖率和激素水平最高 (P<0.01),而抑制PI3K/Akt信号通路,细胞增殖率和激素的分泌量均明显降低(P<0.01);Western blotting结果显示,IGF1R、p-Akt及CYP19A1 蛋白表达水平随着IGF2的浓度梯度逐渐升高(P<0.05),而干预PI3K/Akt信号通路可影响上述蛋白的表达,与对照组相比,IGF2组和IGF2+ LY294002组IGF1R及p-Akt蛋白表达均明显升高（P<0.01）,CYP19A1在IGF2组明显升高（P<0.01）,LY294002组p-Akt及 CYP19A1蛋白明显降低（P<0.05）,IGF1R的表达差异无统计学意义。与IGF2组相比,IGF2+LY294002组p-Akt及CYP19A1蛋白表达降低（P<0.01）,IGF1R的表达差异无统计学意义,LY294002组p-Akt 及CYP19A1蛋白表达量均显著降低（P<0.01）。 结论 IGF2 可能由IGF1R介导通过PI3K/Akt 信号通路促进人卵巢颗粒细胞的增殖及分泌功能。     

沉默S100A12对甲状腺乳头状癌K1细胞增殖、侵袭与迁移的影响

目的 评价沉默S100A12基因对甲状腺乳头状癌细胞K1的增殖、侵袭与迁移能力的影响.方法 用shRNA质粒转染K1细胞沉默S100A12基因,将细胞分为shRNA-NC组和shS100A12组,通过MTT实验评价细胞增殖生长趋势,平板克隆形成实验检测细胞克隆形成数量,Transwell实验检测细胞侵袭迁移能力,细胞划痕实验评价细胞的迁移能力,Western blot实验检测K1细胞E-cadherin,N-cadherin蛋白的表达情况.结果 与shRNA-NC组比较,shS100A12组K1细胞生长趋势明显受到抑制(P＜0.01),细胞克隆形成数量明显下降(P＜0.01),通过通透膜的细胞数量明显减少(P＜0.05),细胞的迁移速率明显减慢(P＜0.01).与shRNA-NC组比较,shS100A12组细胞E-cadherin的表达增高、N-cadherin的表达下降.结论 沉默甲状腺乳头状癌K1细胞中S100A12可以降低细胞增殖、侵袭与迁移能力,S100A12可能通过诱导EMT增强甲状腺乳头状癌细胞的侵袭与迁移能力.     

白细胞介素8对宫颈癌细胞增殖和侵袭转移的影响及其机制*

目的：探讨白细胞介素8（ IL-8） 对宫颈癌细胞Caski 增殖、侵袭转移的影响及其机制。方法：将 体外培养的宫颈癌Caski细胞分为对照组、IL-8 组（20、40、60、80、100 ng/mL）、IL-8+LY294002 组 （80 ng/mL IL-8+20 μmol/L LY294002）以及LY294002 组（20 μmol/L）,采用MTT 实验检测Caski 细胞的增殖能力, 采用划痕实验检测Caski 细胞的侵袭能力,采用Transwell 实验检测Caski 细胞的迁移能力。免疫印迹法检测蛋白 激酶B（ PKB）、磷酸化蛋白激酶B（ p-AKT）、波形蛋白、β-连环蛋白、上皮-钙黏蛋白（ E-cadherin）的表达情 况。结果： IL-8 呈剂量依赖性促进细胞增殖,80 ng/mL 与100 ng/mL 组之间差异无统计学意义。IL-8 组划痕愈合 能力和细胞迁移能力均增强,IL-8+LY294002 组及LY294002 组划痕愈合能力和细胞迁移能力均低于IL-8 组。各 组AKT总蛋白表达量差异无统计学意义,IL-8 组中p-AKT、波形蛋白和β- 连环蛋白表达均增加,E-cadherin 减少, AKT通路特异性抑制剂LY294002 可阻断上述作用。结论：IL-8 可能通过PI3K/AKT 通路影响波形蛋白、β- 连环 蛋白和E-cadherin 蛋白的表达,促进宫颈癌细胞的增殖、侵袭和转移。     

S100A6上调人乳腺癌细胞系MCF-7中β-catenin及其机制

目的 探讨钙细胞周期蛋白S100A6对人乳腺癌细胞系MCF-7中β-catenin的影响及其机制.方法 分别用表达S100A6及其siRNA的重组腺病毒AdS100A6与AdsiS100A6处理MCF-7细胞,RT-PCR、Western blot和免疫细胞化学检测β-catenin、E-钙黏蛋白(E-cadherin)和磷酸化糖原合酶激酶3β(p-GSK3β)表达或分布的变化.结果 在MCF-7细胞中,S100A6可以上调β-catenin的蛋白表达水平(P＜0.01),但对其mRNA表达无显著性影响;S100A6对E-cadherin的mRNA表达、蛋白质表达水平及分布均无显著性影响;S100A6可以提高β-catenin降解复合体的主要成员GSK3β磷酸化水平(P＜0.01).结论 S100A6上调β-catenin的可能机制是通过促进GSK3β磷酸化失活,而不是通过调节E-cadherin实现的.     

乳腺癌细胞过表达HER2/neu时经PI3K和Ras/Raf/MEK/ERK信号通路下调野生型p53蛋白含量

目的 研究HER2/neu基因过表达对乳腺癌细胞野生型p53蛋白含量的影响并探讨其分子机制。方法 脂质体介导的HER2/neu基因转染MCF7细胞,G418筛选阳性克隆。Western印迹法鉴定HER2/neu蛋白表达,并同时检测p53及信号转导分子Akt,p-Akt,p-Raf,p-MEK,p-ERK蛋白含量,以及P13K信号通路抑制剂LY294002和MEK抑制剂U0126处理对p53蛋白含量的影响。逆转录-聚合酶链反应(RT-PCR)检测p53 mRNA水平。结果 成功建立稳定过表达HER2/neu的MCF7细胞(MCF7-neu3),其HER2/neu蛋白表达量是对照组MCF7细胞的13倍。MCF7-neu3中p-Akt,p-Raf,p-MEK,P-ERK蛋白含量分别较MCF7细胞升高了2.5倍、2倍、1.6倍和1.6倍(P<0.01),p53蛋白含量仅为对照组细胞的40％(P<0.01),但p53mRNA表达无明显差异。在经PI3K信号通路抑制剂LY294002及MEK抑制剂U0126处理24 h后,MCF7-neu3细胞p53蛋白含量分别上升了1.7和1.5倍(P<0.01),在LY294002和U0126处理48 h后,p53蛋白含量分别升高了4.7倍和5.3倍(P<0.01)。LY294002和U0126处理对MDA-MB-453细胞突变型p53蛋白含量不产生影响。结论 乳腺癌细胞中HER2/neu基因的过表达能够通过激活P13K和Ras/Raf/MEK/ERK通路导致野生型p53蛋白含量减少,可能是HER2/neu过表达乳腺癌患者预后不良及对治疗产生抗性的分子机制。     

人S100A6对人骨肉瘤细胞系β-catenin的作用

目的 研究人S100A6对人骨肉瘤细胞系MG63和U2OS中β-catenin的作用。方法 分别用携带人S100A6及其siRNA基因的重组腺病毒AdS100A6和AdSiS100A6感染MG63和U2OS,分别使细胞中S100A6表达上调和下调;RT-PCR、蛋白印迹和免疫细胞化学法分别检测细胞中β-catenin mRNA和蛋白表达。结果 上调骨肉瘤细胞系MG63和U2OS中S100A6后, β-catenin mRNA和蛋白表达均增加（P＜0.05）,蛋白的增加以胞核更明显。下调S100A6则使细胞中β-catenin mRNA及蛋白表达减少（P＜0.05）,蛋白的减少也以胞核更甚。结论 增加Wnt信号途径活性可能是S100A6参与肿瘤发生发展的机制之一。     

P13K抑制剂对胶质瘤Akt2、p-Akt表达影响的研究

目的探讨P13K抑制剂LY294002对胶质瘤Akt2、p-Akt表达的影响。方法试验分组：取对数生长期的胶质瘤U251细胞,调整细胞浓度为1&#215;104个/ml,24 h后换液,LY294002组中DMEM高糖培养基含LY294002的浓度设四个梯度,其终浓度分别为5、10、20、40μmol/L 对照组为含等量含有机溶剂DMSO（浓度为0.4%）的DMEM高糖培养基。分别用免疫细胞化学法和Western blot法检测Akt2、p-Akt蛋白的表达。结果胶质瘤细胞株U251细胞中存在Akt2和p-Akt蛋白的高表达,应用P13K抑制剂LY294002可抑制该细胞株细胞中Akt2和p-Akt蛋白的表达,而且其表达呈浓度依赖型降低。结论LY294002可通过抑制P13K活性,抑制Akt的表达及活化,使Akt2和p-Akt蛋白的表达降低,提示抑制P13K/Akt途径可能是LY294002发挥抗肿瘤作用的重要机制,P13K/Akt可能成为胶质瘤治疗的靶点。     

β拉帕醌联合PI3K/mTOR抑制剂NVP-BEZ235抑制BGC-823细胞增殖和迁移

目的研究β拉帕醌(β-lapachone)与磷脂酰肌醇3激酶/哺乳动物雷帕霉素靶蛋白(PI3K/m TOR)抑制剂NVP-BEZ235联合用药对人胃癌BGC-823细胞增殖与迁移的影响及机制。方法将BGC-823细胞分为空白对照组、1μmol/Lβ-lapachone处理组、50 nmol/L NVP-BEZ235处理组及1μmol/Lβ-lapachone联合50 nmol/L NVP-BEZ235处理组。采用MTT法和平板克隆形成实验检测BGC-823细胞的增殖能力;Western blot法检测细胞增殖相关蛋白磷酸化蛋白激酶B(p-AKT)、磷酸化核因子κB(p-NF-κB)、磷酸化的细胞外信号调节激酶(p-ERK)及细胞周期蛋白D1(cyclin D1)的蛋白水平;划痕实验及TranswellTM迁移实验检测细胞迁移能力;Western blot法检测上皮-间质转化(EMT)相关标志物上皮钙黏素(E-cadherin)、波形蛋白(vimentin)、锌指转录因子Snail及β联蛋白(β-catenin)的蛋白水平。结果与β-lapachone处理组或NVP-BEZ235处理组相比,β-lapachone联合NVP-BEZ235处理组能更显著地抑制细胞的增殖和克隆形成能力,p-AKT、p-NF-κB、p-ERK及cyclin D1的蛋白表达下调最明显;在联合处理组对细胞迁移的抑制更明显,EMT相关标志物E-cadherin表达上调,vimentin、Snail及β-catenin表达下调最明显。结论β-lapachone联合NVP-BEZ235可有效抑制BGC-823胃癌细胞增殖,可能与p-AKT、p-NF-κB、p-ERK和cyclin D1表达降低有关;并通过调控EMT进程,抑制BGC-823细胞的迁移。     

下调LRH1 对骨肉瘤细胞生长和Wnt/β-catenin 信号通路的影响

目的：探讨下调肝受体类似物1(LRH1)对骨肉瘤U2OS细胞增殖、侵袭和迁移的影响及其机制。方法：采用RT-qPCR和Western blot分别检测人骨肉瘤细胞U2OS和成骨细胞hFOB1.19中LRH1 mRNA和蛋白表达差异;将体外培养的U2OS细胞分为对照组（Ctrl）、阴性对照（NC）-siRNA组和LRH1-siRNA组,RT-qPCR检测各组U2OS细胞中LRH1 mRNA表达,MTT、流式细胞术、Transwell小室和划痕实验分别检测各组U2OS细胞增殖活力、细胞周期分布情况、穿膜细胞数和划痕愈合率,Western blot检测各组U2OS细胞中LRH1和Wnt/β连环蛋白（β-catenin）信号通路相关蛋白β-catenin、细胞周期素D1(CyclinD1)、c-Myc、基质金属蛋白酶9(MMP-9)表达。结果：与hFOB1.19细胞相比,U2OS细胞中LRH1 mRNA和蛋白表达明显升高（P<0.05）;与NC-siRNA组相比,LRH1-siRNA组U2OS细胞中LRH1 mRNA表达、细胞增殖活力、S期细胞占比、穿膜细胞数、划痕愈合率和LRH1、β-...     

Blocking the PI3K/AKT and MEK/ERK signaling pathways can overcome gefitinib-resistance in non-small cell lung cancer cell lines

PurposeTo investigate the effects of gefitinib (EGFR-TKI), LY294002 (PI3K inhibitor) and U0126 (MEK inhibitor) on proliferation and apoptosis in five non-small cell lung cancer (NSCLC) cell lines (PC9, PC9/AB2, H1975, H1299 and A549).MethodsThe inhibitory rates of cells were tested by MTT and apoptosis was detected through flow cytometry when treated with gefitinib, LY294002 and U0126.ResultsThe sensitivity to gefitinib was different in different cell lines, which was associated with EGFR mutation type. The cells with EGFR mutation were more sensitive than those with EGFR wild-type, except PC9/AB2 cells. LY294002 and U0126 can inhibit cell proliferation and promote apoptosis in all five cell lines. The sensitivity to gefitinib was restored partially in the resistant cell lines by combining gefitinib with LY294002 or U0126. The effects on cell proliferation and apoptosis were stronger in cells with EGFR mutation when PI3K/AKT pathway was blocked, however, for cells with EGFR wild-type, the effects were stronger when the MEK pathway was blocked. When the PI3K and MEK pathways were blocked together, proliferation inhibition and apoptosis level in NSCLC cells was similar to that in cells treated with EGFR TKI. There were some differences according to EGFR mutation type, suggesting that EGFR mutations may result in alterations of downstream signaling pathways.ConclusionThe sensitivity of gefitinib resistant cell lines can be restored partially when the two downstream signaling pathways are blocked. However, these cells were still drug resistant, suggesting that the activation of PI3K and MEK pathways is not the only mechanism of EGFR-resistance.     

Coronarin D suppresses proliferation,invasion and migration of glioma cells via activating JNK signaling pathway

Coronarin D (CD) is one of the primary components of the Hedychium coronarium rhizomes and possesses strong anticancer effects via preventing cell growth in many cancer cells. The study was aimed to explore the molecular mechanisms underlying effects of CD on proliferation, invasion and migration of gliomas cells. Gliomas cell lines U251 was employed for detecting cells viability and proliferation by Cell Counting Kit-8 assay and colony formation assay. In addition, scratch wound healing and transwell assays were performed for the analysis of U251 cells invasion and migration respectively. Furthermore, the expression of p-Akt/Akt, p-p38/p38, p-ERK/ERK, p-JNK/JNK, p-STAT3/STAT3, cyclinE, cyclinD1, CTGF, MMP-2 and MMP-9 were measured by Western blotting. CD could suppress proliferation, invasion and migration of glioma cells and induced reduction of cyclinE, cyclinD1, CTGF, MMP-2 and MMP-9 expression via activating JNK signaling pathway. CD treatment suppressed expression of p-AKT, p38, and ERK and elevated expression of p-JNK in concentration- and time-dependent manners. Moreover, CD significantly induced reduction of phosphorylated STAT3 expression. Exposure of cells to the JNK-specific inhibitor SP600125 reduced the cytotoxicity effects of CD, combination of CD and SP600125 corrected overexpression of phosphorylated JNK and reduction of phosphorylated STAT3. Pretreatment of SP600125 also improves gliomas cells viability and invasion. The results revealed that CD may remarkably suppress gliomas cell growth through JNK and STAT3 signaling. In present study, these findings revealed that CD induces suppression of cell viability in gliomas cells and possesses therapeutic effect on gliomas.     

Activation of the PI3K/Akt/mTOR/p70S6K Pathway is Involved in S100A4-induced Viability and Migration in Colorectal Cancer Cells

The S100 protein family member S100A4 regulates various cellular functions. Previous studies have shown that elevated expression of S100A4 is associated with progression and metastasis of colorectal cancer (CRC). However, little is known about whether and how S100A4 contributes to CRC development. In our present study, the elevated expression of S100A4 in CRC tissues compared to matched adjacent normal tissues was confirmed by immunohistochemistry, semi-quantitative RT-PCR and Western blot. Adenovirus-mediated S100A4 overexpression obviously enhanced viability and migration of CRC cells, which was detected by MTT assay and transwell assay, respectively. Additionally, S100A4 overexpression increased the phosphorylation levels of Akt, mTOR and p70S6K. These effects of S100A4 were abolished by treatment with either the specific PI3K/Akt inhibitor {"type":"entrez-nucleotide","attrs":{"text":"LY294002","term_id":"1257998346","term_text":"LY294002"}}LY294002, or the specific mTOR/p70S6K inhibitor rapamycin. Furthermore, overexpression of S100A4 resulted in upregulation of VEGF and downregulation of E-cadherin, which were strongly reversed by either {"type":"entrez-nucleotide","attrs":{"text":"LY294002","term_id":"1257998346","term_text":"LY294002"}}LY294002 or rapamycin. Altogether, our results demonstrate that activation of the PI3K/Akt/mTOR/p70S6K signaling pathway is involved in S100A4-induced viability, migration, upregulation of VEGF and downregulation of E-cadherin in CRC cells.     

Fibroblast growth factor 8 induced downregulation of thrombospondin 1 is mediated by the MEK/ERK and PI3K pathways in breast cancer cells

Expression of fibroblast growth factor 8 (FGF-8) is increased in several forms of hormonal cancer. It was previously shown to regulate expression of thrombospondin 1 (TSP-1), an inhibitor of angiogenesis, in S115 breast cancer cells. Here, we studied the FGF-8-activated signalling pathways mediating TSP-1 repression in S115 cells and in non-tumorigenic MCF10A cells. Inhibition of FGF receptors or of MEK1/2 and PI3K with specific inhibitors (PD173074, U0126 or LY294002, respectively) restored TSP-1 mRNA expression in the presence of FGF-8 in S115 cells. Furthermore, U0126 and LY294002 increased TSP-1 mRNA expression in S115 cells over-expressing FGF-8. In MCF10A cells, FGF-8 treatment also decreased TSP-1 expression and the effect was dependent on active MEK1/2. In conclusion, FGF-8 suppresses TSP-1 expression through two independent pathways, MEK1/2 and PI3K. Repression of TSP-1 may be an important mechanism involved in induction of an angiogenic phenotype and growth of FGF-8-expressing breast cancer.     

Impact of E6-associated protein on the proliferation and invasion of prostate cancer cells in bone metastasis

Purpose: To understand E6 associated protein (E6-AP)’s influence on prostate cancer cell proliferation and infiltration, thus providing the theoretical basis for developing therapeutic drugs for prostate cancer metastasis to the bone. Methods: Electroporation was performed to introduce linear regulatory plasmid PrevTet-off-in and conjugative plasmid PrevTRE2-flag-E6AP into prostate cancer cell line to establish wild-type E6-AP over-expressing transgenic LNCaP cell line; Western blot assay was adopted to examine expression levels of E6-AP, mammalian target of rapamycin (mTOR), protein kinase B (Akt), and phosphoinositide 3-kinase (PI3K); PI3K inhibitor {"type":"entrez-nucleotide","attrs":{"text":"LY294002","term_id":"1257998346","term_text":"LY294002"}}LY294002 was applied to all the cells and MTT assay was used to measure cell proliferation; Matrigel invasion chamber assay was adopted to detect cancer cell migration and invasion. Results: Stably transfected LNCaP cells that over expressed E6-AP had higher expression levels of PI3K, Akt, and mTOR than control LNCaP cells; MTT assay showed that E6-AP-LNCaP cells were more responsive to the inhibitory effect of {"type":"entrez-nucleotide","attrs":{"text":"LY294002","term_id":"1257998346","term_text":"LY294002"}}LY294002; Matrigel invasion chamber assay revealed increased cell crawling and adhesiveness of E6-AP-LNCaP cells. Conclusion: Stable over-expression of E6-AP increases the proliferation and invasion of LNCaP cells.