PI3K/Akt信号通路在RANKL诱导的MCF-7乳腺癌细胞迁移中的作用

目的 核因子-κB受体活化因子配体(RANKL)能促进表达RANK的上皮癌细胞迁移至骨,与乳腺癌骨转移密切相关.本文探讨磷脂酰肌醇-3-激酶/丝苏氨酸蛋白激酶(phosphoinositide3-kinase/serine/threonine protein kinase PI3K/Akt)信号通路在RANKL诱导的乳腺癌MCF-7细胞迁移中的作用.方法 流式细胞仪检测MCF-7细胞表面RANK蛋白的表达;Transwell法测定RANKL刺激后MCF-7细胞迁移能力的改变;Western-blot检测MCF-7细胞RANKL刺激后p-Akt及Akt的表达.SPSS 16.0软件分析实验数据.结果 MCF-7细胞表达RANK 蛋白,RANKL诱导MCF-7细胞迁移能力显著增强,RANKL的圈套受体OPG可阻断RANKL诱导的细胞迁移.RANKL刺激后MCF-7细胞p-Akt表达在1、5分钟时一过性升高,PI3K抑制剂LY294002显著抑制RANKL诱导的细胞迁移.结论 PI3K/Akt信号通路参与RANKL诱导的乳腺癌细胞系MCF-7迁移.     

趋化因子受体CCR7与PI3K/Akt通路在胃癌组织中的表达及意义

目的 观察趋化因子受体CCR7和磷脂酰肌醇-3-激酶（PI3K）、蛋白激酶B（PKB或Akt）在胃癌组织中的表达情况,探讨CCR7与PI3K/Akt通路的关系。方法 采用RT-PCR法检测32例胃癌及相应癌旁对照组织中CCR7mRNA、PI3KmRNA、AktmRNA的表达;Western Blotting法检测CCR7、p-Akt蛋白的表达。结果 胃癌组织中CCR7mRNA、PI3KmRNA、AktmRNA与癌旁对照组织的表达水平相比,差异均有显著性（P〈0.001）,且CCR7mRNA与PI3KmRNA、AktmRNA表达呈正相关（P〈0.05）。CCR7、P-Akt蛋白在胃癌组织中的表达水平明显高于癌旁对照组织（P〈0.05）,两者表达与肿瘤TNM分期、浸润深度、分化程度、淋巴结转移与远处转移有关（P〈0.05）,并且CCR7、P-Akt表达水平呈正相关（P〈0.05）。结论 胃癌组织中高表达的CCR7可能通过PI3K/Akt通路促进胃癌的侵袭转移。     

c-Src参与RANKL诱导的乳腺癌BT-474细胞迁移的机制研究

目的:核因子-κB受体活化因子配体(RANKL)/核因子κB受体活化因子(RANK)通路在肿瘤骨定向性迁移中发挥重要的作用,但具体信号传导机制尚不清楚。本文探讨非受体酪氨酸激酶c-Src在RANKL诱导的乳腺癌BT474细胞迁移中的作用。方法:Western blot检测BT-474细胞表面受体RANK蛋白的表达及RANKL刺激后细胞p-Src及c-Src的表达;Transwell法测定细胞迁移能力。采用SPSS 16.0统计学软件分析实验数据。结果:BT-474细胞表达RANK蛋白,RANKL诱导BT-474细胞迁移能力增强。应用RANKL的圈套受体OPG可阻断RANKL诱导的细胞迁移。RANKL刺激后BT-474细胞p-Src表达升高,应用c-Src激酶抑制剂PP2可显著抑制RANKL诱导的细胞迁移。结论:c-Src信号通路参与RANKL诱导的乳腺癌BT-474细胞迁移。     

c-Src参与RANKL诱导的乳腺癌BT-474细胞迁移的机制研究

目的：核因子-κB受体活化因子配体（RANKL）/核因子κB受体活化因子（RANK）通路在肿瘤骨定向性迁移中发挥重要的作用,但具体信号传导机制尚不清楚。本文探讨非受体酪氨酸激酶c-Src在RANKL诱导的乳腺癌BT474细胞迁移中的作用。方法：Western blot检测BT-474细胞表面受体RANK蛋白的表达及RANKL刺激后细胞p-Src及c-Src的表达;Transwell法测定细胞迁移能力。采用SPSS 16.0统计学软件分析实验数据。结果：BT-474细胞表达RANK蛋白,RANKL诱导BT-474细胞迁移能力增强。应用RANKL的圈套受体OPG可阻断RANKL诱导的细胞迁移。RANKL刺激后BT-474细胞p-Src表达升高,应用c-Src激酶抑制剂PP2可显著抑制RANKL诱导的细胞迁移。结论：c-Src信号通路参与RANKL诱导的乳腺癌BT-474细胞迁移。     

长链非编码RNA PWRN1通过PI3K/Akt信号通路对乳腺癌细胞增殖、迁移和侵袭的影响

目的 探讨长链非编码RNA Prader-Willi区域非蛋白质编码RNA 1(PWRN1)是否通过磷脂酰肌醇-3-激酶/丝氨酸苏氨酸蛋白激酶(PI3K/Akt)通路调控乳腺癌细胞增殖、侵袭和迁移过程。方法 采用实时荧光定量PCR(q PCR)检测正常乳腺上皮细胞MCF-10A和乳腺癌细胞(BT474、BT549、T47D、MCF7、MDA-MB-453、MDA-MB-231)的PWRN1水平。选择MDA-MB-231细胞并分为空白对照组(不进行转染)、阴性对照组(转染空载体pc DNA3.1)和PWRN1过表达组(转染过表达载体pc DNA3.1-PWRN1)。细胞计数法(CCK-8)、划痕愈合实验和Transwell小室实验分别检测细胞增殖、迁移和侵袭能力。Western blotting和q PCR检测Snail、基质金属蛋白酶9(MMP-9)、磷酸化磷脂酰肌醇3-激酶(p-PI3K)和磷酸化丝氨酸苏氨酸蛋白激酶1(p-Akt1)的水平。结果 乳腺癌细胞的PWRN1水平均低于MCF-10A细胞,差异有统计学意义(P<0.05)。与空白对照组和阴性对照组相比,PWRN1过表达...     

PI3K/AKT信号通路相关蛋白表达与乳腺癌淋巴转移相关性分析

目的:探讨磷脂酰肌醇3-激酶(PI3K)、丝苏氨酸蛋白激酶B(AKT)和血管内皮生长因子受体3(VEGFR-3)在人乳腺癌组织中的表达及其在淋巴转移中的作用。方法:选取60例乳腺癌组织,应用免疫组织化学SP法检测PI3K、AKT和VEGFR-3蛋白的表达,RT-PCR检测PI3K、AKT和VEGFR-3mRNA的表达,并分析其相关性。结果:PI3K在有淋巴结转移组的阳性表达率为78.13%,明显高于无淋巴结转移组53.57%,χ2=4.051 3,P=0.044 1;AKT在有淋巴结转移组的阳性表达率71.88%,明显高于无淋巴结转移组50.00%,χ2=4.029 0,P=0.044 7;VEGFR-3在有淋巴结转移组的阳性表达率为96.89%,明显高于无淋巴结转移组75.00%,χ2=4.435 7,P=0.035 2。60例新鲜标本中,PI3K、AKT和VEGFR-3mRNA在有淋巴结转移的乳腺癌组织中相对表达量分别为0.39±0.17、0.48±0.18和0.42±0.15,明显高于无淋巴结转移组0.31±0.13、0.29±0.23和0.32±0.21,组间比较差异有统计学意义,P值分别为0.047 5、0.000 7和0.036 4。经直线相关分析,PI3K阳性表达组中VEGFR-3的表达为95.00%,PI3K阴性表达组中VEGFR-3表达为70.00%;AKT阳性表达组中VEGFR-3的表达为94.59%,AKT阴性表达组中VEGFR-3的表达为73.91%,在乳腺癌组织中PI3K与VEGFR-3表达呈正相关,r=0.368 5,P=0.003 8;AKT与VEGFR-3表达也呈正相关,r=0.4154,P=0.001。结论:PI3K、AKT和VEGFR-3在乳腺癌组织中的表达呈正相关,PI3K和AKT的表达上调可能促使乳腺癌细胞VEGFR-3过表达,诱导淋巴管生成,促进淋巴转移的发生。     

PI3K/Akt信号转导通路与Basal-like型乳腺癌的分子治疗

磷脂酰肌醇-3激酶/蛋白激酶B (PI3K/Akt)信号转导通路与肿瘤的发生、发展密切相关.研究表明,PI3K/Akt信号通路的活化具有促进乳腺癌细胞增殖及减少细胞凋亡、分化的作用.基底细胞样(Basal-like)乳腺癌是乳腺癌的一种亚型,因其分子表型独特无明确的治疗靶点且恶性程度高、预后差.随着对PI3K/Akt信号转导通路及基底细胞样型乳腺癌发生、发展的研究不断深入,开发应用PI3K/Akt信号通路抑制剂可能为Basal-like型乳腺癌提供有效的分子治疗药物.     

PI3K/Akt/mdm2信号通路活化对胃癌细胞阿霉素敏感性的影响

目的 研究PI3K/Akt/mdm2信号通路活化对胃癌细胞阿霉素(DOX)敏感性的影响.方法 分别用DOX和PI3K特异性抑制剂wortmannin处理胃癌细胞株SGC7901,采用流式细胞仪检测肿瘤细胞的凋亡,免疫沉淀法检测PI3K活性,Western blot法检测PI3K-p85、phospho-Akt(S473)、phospho-mdm2(S166)、Akt和p53的表达.结果 DOX能诱导胃癌细胞SGC7901凋亡,且凋亡率与作用时间密切相关,联合应用wortmannin后,可促进胃癌细胞凋亡.DOX作用SGC7901细胞3、6、12和24 h后, PI3K活性逐渐增强,分别为(8.4±1.7)%、(12.7±2.1)%、(17.4±3.2)%和(16.8±2.4)%;同时,还促进Akt、mdm2磷酸化和p53表达.wortmannin可以抑制mdm2磷酸化,进一步增强p53的表达.结论 DOX可以诱导PI3K/Akt通路异常激活,并通过促进mdm2磷酸化降低胃癌细胞化疗敏感性.     

PI3K/AKT/mTOR通路及其抑制剂在乳腺癌中的应用现状

磷脂酰肌醇3-激酶（phosphoinositide 3-kinase,PI3K）/蛋白激酶B（protein kinase B,AKT）/哺乳动物雷帕霉素靶蛋白（mammalian target of rapamycin,mTOR）信号转导通路在多种肿瘤中异常激活,参与肿瘤细胞增殖、分化和凋亡等生命过程的调控,是抗肿瘤药物研发的重要靶点。对目前已应用于乳腺癌临床或处于临床试验阶段的PI3K/AKT/mTOR信号通路抑制剂进行归纳,并综述该通路抑制剂的联合用药策略,以期为不同亚型乳腺癌提供个体化靶向治疗方案。     

PI3K/Akt信号传导通路在妇科肿瘤中的研究进展

磷脂酰肌醇3激酶/蛋白激酶B( PI3K/Akt)信号传导通路具有重要的细胞调节功能,对肿瘤的发生、发展也发挥着重要的作用.本文主要探讨PI3K/Akt信号转导途径与妇科肿瘤的关系.     

ERK信号通路参与RANKL诱导的乳腺癌细胞迁移

目的：探讨细胞外调节蛋白激酶（ERK）信号通路在RANKL诱导的乳腺癌细胞迁移中的作用.方法：流式细胞术检测MDA-MB-231细胞表面RANK蛋白的表达;western-blot检测RANKL刺激后磷酸化ERK（P-ERK）及ERK的表达;Transwell法测定RANKL刺激后细胞迁移能力的改变.结果：MDA-MB-231细胞表达RANK蛋白,RANKL诱导MDA-MB-231细胞迁移能力增强.RANKL刺激后MDA-MB-231细胞P-ERK表达升高,PD98059抑制RANKL诱导的细胞迁移.结论：ERK信号通路参与RANKL诱导的乳腺癌细胞迁移.     

贝母素乙通过调控PI3K/Akt信号通路诱导乳腺癌MCF-7细胞凋亡

目的：探究贝母素乙（Peiminine）对乳腺癌细胞MCF-7细胞凋亡的影响及其可能作用机制。方法：采用不同浓度贝母素乙或联合PI3K抑制剂LY294002干预MCF-7细胞,MTT法检测细胞增殖能力;Hoechst33258染色和Annexin V-FITC/PI流式细胞术检测细胞凋亡情况;JC-1染色法检测细胞线粒体膜电位变化;Western blotting检测细胞中PI3K(p110α)、Akt、p-Akt(ser473)、Bad、Bax、Bcl-2、cleaved-Caspase-3以及线粒体和胞浆中细胞色素C(Cyt C)等蛋白表达水平。结果：贝母素乙可呈时间-浓度依赖性抑制MCF-7细胞增殖,诱导细胞出现凋亡形态改变,促进细胞凋亡,并降低线粒体膜电位,上调细胞中Bad、Bax、cleaved-Caspase-3及胞浆中Cyt C蛋白表达水平,下调PI3K(p110α)、p-Akt、Bcl-2和线粒体中Cyt C蛋白表达水平,而Akt蛋白表达水平无显著变化。然而,联合LY294002干预可增强贝母素乙对MCF-7细胞凋亡的促进作用。结论：贝母素乙可诱导乳腺癌MCF-7细胞凋...     

Activation of IL-8 via PI3K/Akt-dependent pathway is involved in leptin-mediated epithelial-mesenchymal transition in human breast cancer cells

Background Information: Previous studies have revealed that leptin may be involved in epithelial-mesenchymal transition (EMT), a crucial initiator of cancer progression to facilitate metastatic cascade, increase tumor recurrence, and ultimately cause poor prognosis. However, the underlying mechanism remains unclear. The aim of our present study was to investigate the effect of leptin on EMT of breast cancer cells and the underlying mechanism. Results: Our data demonstrated that leptin significantly increased the phosphorylation of STAT3, Akt, and ERK1/2, elevated the expression of IL-8, and induced breast cancer cells to undergo EMT. The effect of leptin on IL-8 could visibly abolished by the inhibitor of PI3K {"type":"entrez-nucleotide","attrs":{"text":"LY294002","term_id":"1257998346","term_text":"LY294002"}}LY294002. In addition, leptin-induced EMT of breast cancer cells was blocked by anti-IL-8 antibodies. Examination of the expression of ObR, leptin, IL-8 and EMT-related biomarkers in patient specimens demonstrated that malignant breast carcinoma with lymph node metastases (LNM), which represents poor prognosis, expressed higher levels of ObR, leptin, IL-8 than other types of breast cancer, and displayed more obvious EMT transversion. In vivo xenograft experiment revealed that leptin signally promoted tumor growth and metastasis and increased the expressions of IL-8 and EMT-related biomarkers. Conclusions: Our results support that leptin-induced EMT in breast cancer cells requires IL-8 activation via the PI3K/Akt signal pathway.     

Reduced PTEN expression in breast cancer cells confers susceptibility to inhibitors of the PI3 kinase/Akt pathway.

The PTEN protein is a lipid phosphatase with putative tumor suppressing abilities, including inhibition of the PI3K/Akt signaling pathway. Inactivating mutations or deletions of the PTEN gene, which result in hyper-activation of the PI3K/Akt signaling pathway, are increasingly being reported in human malignancies, including breast cancer, and have been related to features of poor prognosis and resistance to chemotherapy and hormone therapy. Prior studies in different tumor models have shown that, under conditions of PTEN deficiency, the PI3K/Akt signaling pathway becomes a fundamental proliferative and survival pathway, and that pharmacological inhibition of this pathway results in tumor growth inhibition. This study aimed to explore further this hypothesis in breast cancer cells. To this end, we have determined the growth response to inhibition of the PI3K/Akt signaling pathway in a series of breast cancer cell lines with different PTEN levels. The PTEN-negative cell line displayed greater sensitivity to the growth inhibitory effects of the PI3K inhibitor, LY294002 and rapamycin, an inhibitor of the PI3K/Akt downstream mediator mTOR, compared with the PTEN-positive cell lines. To determine whether or not these differences in response are specifically due to effects of PTEN, we developed a series of cell lines with reduced PTEN protein expression compared with the parental cell line. These reduced PTEN cells demonstrated an increased sensitivity to the anti-proliferative effects induced by LY294002 and rapamycin compared with the parental cells, which corresponded to alterations in cell cycle response. These findings indicate that inhibitors of mTOR, some of which are already in clinical development (CCI-779, an ester of rapamycin), have the potential to be effective in the treatment of breast cancer patients with PTEN-negative tumors and should be evaluated in this setting.     

Boosting immune surveillance by low-dose PI3K inhibitor facilitates early intervention of breast cancer

Prevention of estrogen receptor-negative (ER-) breast cancer is an unmet challenge, although tamoxifen and aromatase inhibitors can successfully decrease the incidence of ER-positive (ER+) breast cancer. PI3K pathway activation has been detected in tamoxifen-resistant ER- breast lesions of patients. Here, we further ratified that the PI3K pathway is significantly activated in premalignant ER- breast lesions compared with paired normal tissues of patients, which prompted our assessment of targeting PI3K on inhibition of ER- mammary tumor initiation and progression. Both genetic knockdown of PIK3CA or intervention with low-doses of a PI3K inhibitor (GDC-0941) prevented the dysplasia phenotype of semi-transformed human ER- mammary epithelial cells in 3-dimensional culture in vitro. Importantly, low-dose GDC-0941 treatment significantly delayed mammary tumor initiation in the MMTV-neu mouse model without exhibiting discernable adverse effects. Interestingly, increased CD8⁺/GZMB⁺ T-cells were detected in mammary tissue after GDC-0941 treatment, suggesting enhanced immune surveillance. Mechanistically, elevated expression of potent T-cell chemo-attractants, including CCL5 and CXCL10, were detected both in vitro and in vivo after GDC-0941 treatment. Furthermore, inhibition of PI3K significantly increased T-cell recruitment in a CCL5/CXCL10-dependent manner. In human ER- breast cancer, PI3K activation is correlated with significantly reduced CCL5, CXCL10 and CD8A expression, suggesting that the decreased CD8⁺ T-cell recruitment and escape of immune surveillance may contribute to ER- breast cancer development. In summary, our study indicates that low-dose PI3K inhibitor treatment may intervene early stage ER- breast cancer development by enhancing immune surveillance via CCL5/CXCL10.     

阻断PI3K/AKT通路对乳腺癌细胞放射敏感性影响的研究

目的 研究抑制磷脂酰肌醇3激酶和（或）蛋白激酶B（P13K／AKT）生存传导路径是否改变乳腺癌细胞的放射敏感性。方法 用乳腺癌细胞细胞株MCF7为实验对象，分别接受单纯放射、Ly294002（P13K抑制剂）和二者结合处理。通过Western印记法证实Ly294002可下调AKT活性。采用成克隆法定量分析细胞增殖性死亡。通过半胱天冬酶-3（easpase-3）活性评估细胞凋亡。结果 单纯Ly294002（5μmol／L）可抑制AKT的磷酸化，而单纯放射对AKT的活性无明显影响，二者结合可提高对AKT活性的抑制作用。Ly294002（5μmol／L）在放射前与细胞作用1h及放射后作用10d均可提高MCF7细胞对放射的敏感性。Ly294002结合放射可增加MCF7细胞增殖性死亡，SF4值的放射增敏比为1．25，D0值的放射增敏比为1．42。Ly294002可增加MCF7细胞放射后诱导的细胞凋亡。结论 抑制P13K通过降低AKT活性，增加MCF7细胞对放射的敏感性，为筛选放射敏感剂进行临床实验提供了依据。