Skp2蛋白在非小细胞肺癌中的表达及其与p27kip1蛋白表达的关系

目的探讨Skp2蛋白表达在非小细胞肺癌(NSCLC)发生、发展中的作用及其与p27k ip1蛋白表达的关系。方法应用免疫组化S-P法检测60例NSCLC和20例正常支气管黏膜上皮组织中Skp2、p27k ip1蛋白的表达。结果NSCLC组织中Skp2蛋白表达的阳性率为48.33%(29/60),显著高于正常支气管黏膜组织中的表达(P<0.01);Skp2的表达与肿瘤的组织学类型、分化程度、淋巴结转移和患者吸烟与否显著相关,但与年龄、性别无关;NSCLC组织中Skp2表达与p27k ip1表达呈显著负相关(P<0.01)。结论NSCLC中Skp2蛋白表达与靶蛋白p27k ip1蛋白降解有关,提示Skp2蛋白过表达可能在NSCLC的发生和发展中起重要作用。     

非小细胞肺癌组织中PTEN/p27kip1的表达及其意义

目的检测PTEN、p27kip1、cyclin 3种蛋白在非小细胞肺癌组织的表达及与临床病理特征的关系.方法在60例非小细胞肺癌原发灶(包括37例鳞癌和23例腺癌)中应用免疫组织化学S-P法检测3种蛋白的表达.结果 60例肺癌原发灶中PTEN、p27kip1、cyclin 3种蛋白表达阳性率分别为:48.3%;41.7%;73.3%.PTEN与淋巴结转移显著相关(<0.05)p27kip1、cyclin 与淋巴结转移无关(>0.05)这3种蛋白表达均与肿瘤细胞分化程度显著相关(<0.05)与组织学类型无关(>0.05)60例非小细胞肺癌组织中,PTEN的表达与p27kip1呈显著正相关(P<0.01),而与cyclin 无明显相关(>0.05)p27kip1与cyclin 的表达之间呈显著负相关(P<0.01).结论 PTEN明显地抑制了非小细胞肺癌的浸润和转移,p27kip1表达缺失与肺癌细胞的分化有关,PTEN/p27kip1衰老诱导途径在非小细胞肺癌的恶性进展中起着很重要的作用.     

miR-124对非小细胞肺癌细胞增殖的影响及其机制

目的 探讨miR-124对非小细胞肺癌(NSCLC)细胞增殖的影响及其机制.方法 采用CCK8法和克隆形成实验评估miR-124对细胞增殖能力的影响.采用实时荧光定量PCR(qRT-PCR)和Western blot检测miR-124转染后细胞内PIM3的表达水平.通过双荧光素酶报告系统检测miR-124对PIM3荧光素酶活性的影响,证实miR-124可靶向作用于PIM3的3'UTR区.采用qRT-PCR和Western blot检测si-PIM3转染后细胞内PIM3的表达情况,采用CCK8法和克隆形成实验检测沉默PIM3后对细胞增殖能力的影响.结果 ①miR-124模拟物组的细胞活性(OD值)低于其对照组,差异有统计学意义,且呈时间依赖性;miR-124模拟物组的克隆形成数明显少于其对照组.②miR-124模拟物组的miR-124过表达后,其PIM3表达低于其对照组,差异有统计学意义.③含野生型结合位点(PIM3 3'UTR区完整片段)的miR-124模拟物组的荧光素酶活性低于其对照组,差异有统计学意义;含突变型结合位点(PIM3 3'UTR区突变片段)的两组无明显差异.④si-PIM3组的PIM3被沉默后,其表达水平明显低于其对照组,差异有统计学意义;si-PIM3组的细胞活性(OD值)低于其对照组,差异有统计学意义,且呈时间依赖性;si-PIM3组的克隆形成数明显少于其对照组.结论 miR-124可通过靶向作用于PIM3的3'UTR区下调后者的表达而抑制NSCLC细胞的增殖.     

p27kip1亚细胞定位与肿瘤

p27kip1是一种广谱的细胞周期蛋白依赖激酶(cyclin-dependent kinases,CDKs)抑制剂,主要通过抑制CDK的活性,来阻断细胞周期中G1/S期的转换,从而实现对细胞周期的负调控.p27 kip1基因除了作为抑癌基因还有致瘤的潜能.这种双向性又在其亚细胞定位中体现,p27 kip1多个位点的磷酸化参与p27 kip1亚细胞定位的调控.这些研究可能对肿瘤的预后提示和治疗方面具有重要意义.本文就p27kip1亚细胞定位在肿瘤研究中的作用、磷酸化对p27kip1亚细胞定位的影响及p27kip1的研究对肿瘤治疗及预后方面的影响进行综述.     

miR-21调控非小细胞肺癌细胞增殖和凋亡的机制研究

目的 研究非小细胞肺癌(NSCLC)中高表达的miR-21对细胞增殖和凋亡的影响及其调控机制.方法 采用荧光定量聚合酶链反应检测miR-21在人NSCLC组织、癌旁组织和A549细胞系中的表达.通过序列分析预测被miR-21调控的抑癌基因,通过荧光素酶活性检测和Western blot 检测验证miR-21对靶基因表达调控的影响.采用RNA干扰技术抑制miR-21和程序性细胞死亡因子4(PDCD4),以台盼蓝染色和流式细胞术检测A549细胞增殖和凋亡的变化.结果 NSCLC组织和A549细胞中miR-21的表达水平分别为癌旁组织的2.24倍和3.06倍.序列预测和基因表达调控研究表明,miR-21可以在NSCLC中反向调控PDCD4的表达(P＜0.01).荧光素酶活性检测结果显示,共同转入Wt 3'UTR和miR-21会显著抑制A549细胞中的荧光素酶表达(P＜O.001).Western blot检测结果显示,导入反义寡核苷酸抑制miR-21的功能后,PDCD4的表达水平明显上升.抑制miR-21的作用可以显著抑制A549细胞的增殖,并使细胞凋亡率由2.6％上升到10.9％,而抑制PDCD4的表达可以在很大程度上消除miR-21介导的细胞增殖障碍,抑制细胞凋亡.结论 在NSCLC中,抑制抑癌基因PDCD4的表达可能是miR-21介导肿瘤细胞增殖、抵抗凋亡的重要途径之一.     

miR-150-5p调控非小细胞肺癌的A549细胞凋亡的机制研究

目的 探讨miR-150-5p调控非小细胞肺癌A549细胞凋亡的分子机制.方法 过表达或敲低miR-150-5p后,检测非小细胞肺癌A549的凋亡水平.敲低miR-150-5p后,检测miRDB数据库在线分析的靶标的mRNA水平.通过荧光素酶报告系统检测miRNA是否与潜在靶标直接结合.过表达或敲低靶标后,分析非小细胞...     

长链非编码RNA MSC-AS1通过调控miR-302c-3p/SSX2 IP促进非小细胞肺癌细胞增殖

目的:检测长链非编码RNA肌蛋白反义RNA1(musculin antisense RNA 1,MSC-AS1)在非小细胞肺癌(non-small cell lung cancer,NSCLC)组织和细胞中的表达,研究其对肿瘤细胞增殖的影响并探索其机制.方法:采用qRT-PCR技术检测NSCLC肿瘤组织、癌旁组织、肺癌...     

CyclinD1和p27在非小细胞肺癌组织中的表达及其临床意义

目的研究细胞周期蛋白CyclinD1和p27在非小细胞肺癌（NSCLC）组织中的表达及其临床意义。方法应用S-P免疫组化法检测63例非小细胞肺癌组织中CyclinD1和p27的表达，取20例肺部正常组织做对照，并结合临床资料进行分析。结果在非小细胞肺癌组织中CycinD1呈高表达，p27呈低表达，与对照组均有组间差异（P〈0．05）。CyclinD1和p27的表达均与肿瘤的分化程度、淋巴结转移、临床分期有关（P〈0．05），而与年龄、性别、组织学类型无关（P〉0．05）；NSCLC组织中CyclinD1与p27表达呈显著负相关（P〈0．01）。结论CyclinD1癌基因和p27抑癌基因突变协同作用使非小细胞肺癌发生与发展。二者的检测可作为肺癌的早期诊断指标、评价非小细胞肺癌恶性程度和判断预后的重要指标。     

miR-363-3p和miR-5100在非小细胞肺癌中的表达及其临床意义

目的:探讨小分子RNA(microRNA)miR-363-3p 和miR-5100在非小细胞肺癌中的表达及其临床意义.方法:利用荧光定量PCR的方法,检测肿瘤组织、癌旁组织及远离肿瘤的正常组织中致癌基因Myc的mRNA 和miR-363-3p、miR-5100的表达,然后分析miR-363-3p 和miR-5100与临床病理特征之间的相关性.结果:Myc在肿瘤组织中表达明显升高;miR-363-3p在肺癌组织中的表达明显低于正常组织(P<0.001),而在癌旁组织中的表达却远远高于正常组织(P<0.05);miR-5100在肺癌组织中的表达显著地高于正常组织(P<0.001),并且癌旁组织中的表达也高于正常组织(P<0.05).临床相关性分析显示,miR-363-3p的表达与淋巴结转移呈正相关(P<0.001),miR-5100的表达与临床分期也呈正相关性(P<0.05).结论:miR-363-3p 和miR-5100可能参与了非小细胞肺癌早期的发生和转移,并可能作为早期诊断和预后的分子标志物.     

p27kip1:细胞周期的正/负双向调控因子?

细胞周期是细胞生命活动的基本过程,机体中存在着精密的机制参与这一过程的调控,目前最令人瞩目的是cyclin-CDK-CKI组成的复杂分子网络.p27kip1是CIP/KIP家族的主要成员,传统的观点认为p27kip1仅作为CDK的抑制因子参与细胞周期的负向调控,但有证据表明在特定的条件下p27kip1对于细胞周期也存在着正向调控作用.p27kip1在细胞周期中究竟扮演着怎样的"角色"?它是否具有"双重身份"?这种矛盾是如何得到统一的?     

miR-196a调控HOXA5对人胃癌细胞MGC-803侵袭转移的影响及机制研究

目的 检测miR-196a在人胃癌组织及细胞系中的表达,探讨抑制或过表达miR-196a对胃癌细胞侵袭转移能力的影响,以及其可能作用的靶基因。方法 通过实时定量PCR技术检测胃癌组织及细胞系中miR-196a的表达水平,通过转染miR-196a inhibitors或mimics抑制或上调其表达,并通过定量PCR检测转染效率。利用划痕迁移实验、Transwell侵袭实验和MTT实验检测上调或下调miR-196a水平对MGC-803细胞的迁移、侵袭和增殖能力的影响。采用生物信息学及Western blotting方法验证miR-196a对靶基因HOXA5的调控机制。结果 相对于正常胃黏膜组织及细胞,胃癌组织和细胞系中miR-196a的表达水平显著上调（上调约28倍,P＜0.01）,MGC-803细胞中转染miR-196a inhibitors或mimics能显著抑制（下降了53％,P＜0.01）或上调（上调约8倍,P＜0.01）miR-196a表达水平。抑制miR-196a表达能降低MGC-803细胞的迁移、侵袭和增殖能力,而上调其表达则相反。miR-196a能够负性调控HOXA5的表达。结论 胃癌组织及细胞系中miR-196a的表达上调可能通过抑制HOXA5的表达显著提高胃癌细胞的侵袭转移能力,促进胃癌的发生、发展。     

MicroRNA-196a promotes cervical cancer proliferation through the regulation of FOXO1 and p27Kip1

Background:

The phosphoinositide 3-kinase (PI3K)/Akt signalling pathway appears to be a key regulator in cervical carcinogenesis. However, the downstream regulatory mechanism of PI3K/Akt signalling remains largely unknown.

Methods:

The expression of miR-196a in cervical cancer cell lines and cervical cancer tissues was examined using real-time PCR. The effects of miR-196a on PI3K/Akt signalling and cellular proliferation were evaluated by bromodeoxyuridine labelling, 3-(4,5-Dimethyl-2-thiazolyl)-2,5-diphenyl-2H-tetrazoliumbromide, colony formation assays and luciferase assays.

Results:

The expression level of miR-196a was markedly increased in cervical cancer tissues and cell lines compared with normal cervical tissue and normal cervical squamous cells. Upregulation of miR-196a was correlated with advanced tumour stage and poor overall and recurrence-free survival in cervical cancer patients. Upregulation of miR-196a enhanced G1/S-phase transition and the proliferative ability of cervical cancer cells, whereas suppression of miR-196a had the opposite effect. Using bioinformatics and biological approaches, we showed that FOXO1 and p27^Kip1, two key effectors of PI3K/Akt signalling, were direct targets of miR-196a.

Conclusions:

Our findings suggest that miR-196a has an important role in promoting human cervical cancer cell proliferation and may represent a novel therapeutic target of microRNA-mediated suppression of cell proliferation in cervical cancer.     

反义miR-221/222上调p27kip1对MCF-7乳腺癌细胞系的放射增敏作用

目的探讨敲低miR-221／222表达上调p27^kip1对MCF-7人乳腺癌细胞系放射敏感性的影响。方法经生物信息学分析查询miR-221／222成熟体序列和它们与p27^kip1的关系。脂质体共转染反义寡聚核苷酸（反义miR-221／222）后,用Northern blot法检测转染后MCF-7细胞miR-221、miR-222表达水平;将实验细胞分为6组：对照组、对照照射组、无义序列组、无义序列照射组、反义miR-221／222共转染组和反义miR-221／222共转染照射组。用MTT法检测细胞增殖及放射协同作用,流式细胞仪分析细胞周期,克隆形成实验检测细胞增殖,Western blot分析p27^kip1蛋白的表达变化。数据间的方差分析采用F检验;两两比较采用LSD-t检验。结果经生物信息学分析显示miR-221／222成熟体序列的种子序列几乎一致,p27^kip1是miR-221／222的靶基因。Northern blot显示反义miR-221／222共转染组miR-221、miR-222的表达水平明显下降（miR-221：P=0．000;miR-222：P=0．000）。对照组及无义序列组之间miR-221、miR-222表达水平的差异无统计学意义（miR-221：P=0．371;miR-222：P=0．284）。MTT结果显示转染后第4天共转染组肿瘤细胞生长抑制效果最好,细胞增殖率明显低于对照组和无义序列组（P=0．000）,但与放射治疗无协同作用（P=0．091）。流式细胞术检测可见共转染组细胞周期存在G0／G1期阻滞（P=0．000）。经放射治疗后,可明显降低S期比例（P=0．002）。克隆形成实验表明反义miR-221／222可增加MCF-7细胞的放射敏感性。Western blot显示反义miR-221／222共转染组的p27^kip1蛋白表达明显上调（P=0．000）。结论反义miR-221／222通过上调p27^kip1蛋白表达可以增加MCF-7人乳腺癌细胞系放射敏感性。     

槲皮素通过调控p21/cip1和p27/kip1蛋白的稳定性抑制口腔鳞状细胞癌细胞增殖

目的:探究槲皮素通过调控p21/cip1和p27/kip1蛋白的稳定性对口腔鳞状细胞癌细胞增殖的影响.方法:CCK-8试剂盒检测口腔鳞状细胞癌细胞(SCC-15)增殖情况;流式细胞术检测SCC-15细胞周期分布;Western blot检测CyclinD1/CDK复合体、p21/cip1、p27/kip1、p-GSK3...     

lncRNA SNHG1通过抑制p27kip1促进胃癌细胞的增殖作用

目的:确定长链非编码RNA SNHG1（lncRNA SNHG1）在胃癌中的表达，并探讨其在胃癌细胞增殖中的作用。方法:通过原位杂交及实时荧光定量PCR（RT-qPCR）检测26例胃癌患者肿瘤组织及相应癌旁组织中SNHG1的表达。同时通过RT-qPCR检测正常胃上皮细胞及胃癌细胞系中SNHG1的表达情况。为评估SNHG1对胃癌细胞增殖能力的影响，向胃癌细胞系中转染shRNA或pcDNA调控SNHG1表达，并通过CCK-8法、流式细胞术及克隆形成实验检测细胞活力、细胞周期与细胞形成集落的能力。通过相关性分析、免疫组化、RT-qPCR及Western blot等方法检测了胃癌组织及细胞中p27kip1的表达，并进一步研究其与SNHG1的关系。结果:lncRNA SNHG1在胃癌组织中的表达明显高于癌旁组织，尤其是在肿瘤中晚期。SNHG1可明显促进胃癌细胞的增殖，缩短细胞周期，增强肿瘤细胞的集落形成能力。同时胃癌组织及细胞系中p27kip1与SNHG1存在相关性，上调SNHG1可以抑制胃癌细胞中p27kip1的表达，反之亦然。上调p27kip1可以拮抗SNHG1对胃癌细胞增殖能力的促进作用。结论:lncRNA SNHG1通过抑制p27kip1促进胃癌细胞增殖，表明SNHG1可能成为胃癌的潜在治疗靶点。     

miR-221 confers lapatinib resistance by negatively regulating p27kip1 in HER2-positive breast cancer

Development of acquired resistance to lapatinib, a dual epidermal growth factor receptor (EGFR)/human epidermal growth factor receptor 2 (HER2) tyrosine kinase inhibitor, severely limits the duration of clinical response in advanced HER2-driven breast cancer patients. Although the compensatory activation of the PI3K/Akt survival signal has been proposed to cause acquired lapatinib resistance, comprehensive molecular mechanisms remain required to develop more efficient strategies to circumvent this therapeutic difficulty. In this study, we found that suppression of HER2 by lapatinib still led to Akt inactivation and elevation of FOX3a protein levels, but failed to induce the expression of their downstream pro-apoptotic effector p27^kip1, a cyclin-dependent kinase inhibitor. Elevation of miR-221 was found to contribute to the development of acquired lapatinib resistance by targeting p27^kip1 expression. Furthermore, upregulation of miR-221 was mediated by the lapatinib-induced Src family tyrosine kinase and subsequent NF-κB activation. The reversal of miR-221 upregulation and p27^kip1 downregulation by a Src inhibitor, dasatinib, can overcome lapatinib resistance. Our study not only identified miRNA-221 as a pivotal factor conferring the acquired resistance of HER2-positive breast cancer cells to lapatinib through negatively regulating p27^kip1 expression, but also suggested Src inhibition as a potential strategy to overcome lapatinib resistance.     

MTA1 promotes the invasion and migration of non-small cell lung cancer cells by downregulating miR-125b

Background

The metastasis-associated gene 1 (MTA1) has been identified as one critical regulator of tumor metastasis. Previously, we identified miR-125b as a downregualted miRNA in non-small cell lung cancer (NSCLC) cell line upon MTA1 depletion. However, the role of miR-125b and MTA1 in the regulation of NSCLC metastasis remains unclear.

Methods

Stable MTA1 knockdown NSCLC cell lines 95D and SPC-A-1 were established by transfection with MTA1 shRNA. The effects of MTA1 depletion on the expression of miR-125b and cell migration and invasion were examined by real-time PCR, wound healing and matrigel invasion assay.

Results

MTA1 knockdown led to the upregulation of miR-125b level in NSCLC cells. Furthermore, MTA1 knockdown reduced while miR-125b inhibitor enhanced cell migration and invasion of NSCLC cells. Notably, miR-125b inhibitor antagonized MTA1 siRNA induced inhibition of cell migration and invasion.

Conclusion

MTA1 and miR-125b have antagonistic effects on the migration and invasion of NSCLC cells. The newly identified MTA1-miR-125b axis will help further elucidate the molecular mechanism of NSCLC progression and suggest that ectopic expression of miR-125b is a potentially new therapeutic regimen against NSCLC metastasis.     

Contact inhibition modulates intracellular levels of miR-223 in a p27kip1-dependent manner

MicroRNAs (miRs) are a large class of small regulatory RNAs that function as nodes of signaling networks. This implicates that miRs expression has to be finely tuned, as observed during cell cycle progression.Here, using an expression profiling approach, we provide evidence that the CDK inhibitor p27^Kip1 regulates miRs expression following cell cycle exit. By using wild type and p27KO cells harvested in different phases of the cell cycle we identified several miRs regulated by p27^Kip1 during the G1 to S phase transition. Among these miRs, we identified miR-223 as a miR specifically upregulated by p27^Kip1 in G1 arrested cells. Our data demonstrate that p27^Kip1 regulated the expression of miR-223, via two distinct mechanisms. p27^Kip1 directly stabilized mature miR-223 expression, acting as a RNA binding protein and it controlled E2F1 expression that, in turn, regulated miR-223 promoter activity. The resulting elevated miR-223 levels ultimately participated to arresting cell cycle progression following contact inhibition. Importantly, this mechanism of growth control was conserved in human cells and deranged in breast cancers.Here, we identify a novel and conserved function of p27^Kip1 that, by modulating miR-223 expression, contributes to proper regulation of cell cycle exit following contact inhibition. Thus we propose a new role for miR-223 in the regulation of breast cancer progression.