Stathmin蛋白:一个潜在的肿瘤标志物

人stathmin也称原癌基因蛋白18(oncogene protein 18, Op18), 是一种广泛存在于细胞质的蛋白质,其相对分子质量约为19×10~3,可与微管蛋白结合,参与微管和纺锤体的组装;与细胞的增殖、分化、再生和运动均有关,并具有信号活性调节的功能.近年来有研究发现,stathmin在多种肿瘤中高表达,并可通过调节微管的解聚,促进肿瘤细胞的运动及侵袭.Stathmin翻译后修饰状态的改变,可影响与p53蛋白的相互作用,参与肿瘤的发生发展.目前单独或者联合化疗药物使用的抗stathmin效应剂已用于某些肿瘤的治疗.虽然stathmin与肿瘤病因学的内在联系尚不十分清楚,但其作为一个潜在的肿瘤标志物或药物靶点值得进一步研究探讨.     

Stathmin基因表达与肿瘤的研究进展

Stathmin在多种恶性肿瘤细胞中都有高水平表达，Stathmin蛋白的主要作用是通过促进微管的解聚或阻止微管的聚合从而影响有丝分裂纺锤体的形成，通过抑制其表达可以干扰恶性肿瘤细胞的有丝分裂，影响肿瘤细胞的增殖与凋亡。同时，抑制stathmin表达能够协同增效某些化疗药物的抗癌疗效。Stathmin基因正成为肿瘤基因治疗的一个新靶点。     

微管不稳定蛋白Stathmin--肿瘤基因治疗新靶点

微管不稳定蛋白Stathmin在细胞周期的不同阶段对微运动力平衡的调节发挥重要作用。多种恶性肿瘤中Stathmin都有高水平表达，抑制其表达可以干扰恶性细胞的细胞分裂、Stathmin的过表达可干扰紫杉醇与微管的结合，但增加长春碱类药物与微管的结合能力，临床用药时应予考虑。另外．Stathmin为肿瘤基因治疗提供了一个分子新靶点，腺病毒介导抗stathmin核酶治疗联合察素药物治疗可能获得更强有力的抗增殖和抗肿瘤效应。     

stathmin基因的表达与长春瑞滨治疗非小细胞肺癌疗效关系

背景与目的: 化疗是晚期非小细胞肺癌(NSCLC)的主要治疗手段,但是NSCLC常对化疗耐药,导致治疗失败.因此,针对不同分子生物学特点的NSCLC进行化疗疗效预测,成为提高疗效的重要方法.本研究通过研究晚期NSCLC患者肿瘤组织中Stathmin基因的表达与患者对长春碱类药物的化疗敏感性的关系,为患者选择适当的药物治疗提供依据.方法:2005年5月-2007年12月,共78例晚期NSCLC患者入组,随机分ANP方案[长春瑞滨(NVB)联合顺铂(DDP)或卡铂(CBP)]化疗组或GP方案[吉西他滨(GEM)联合DDP或CBP]化疗组,观察两组对化疗的反应;同时以RT-PCR法检测患者病理组织中Stathmin mRNA的表达,以Western印迹法检测Stathmin的蛋白含量.结果: NP组41N,GP组37例,两组患者的性别、年龄、病理类型及肿瘤分期等临床特点无显著性差异(P>0.05),对化疗总的有效率分别为46.3%(19/41)和48.6%(18/37),两者之间亦未见显著差异(P>0.05);在NP组内,有效19例,无效22例,有效患者的肿瘤组织中stathmin mRNA测量值为1.9±1.1,而无效患者为7.5±2.8,两者之间差异有显著性(P=0.003).有效患者的Stathmin蛋白测量值为1.5±0.7.无效组为4.3±1.6,两者之间差异有显著性(P=0.002).GP组18例有效,19例无效,有效与无效患者肿瘤组织中stathmin mRNA及Stathmin蛋白无明显差异(P>0.05). 结论: NSCLC患者肿瘤组织中stathmin基因的表达与患者对长春碱药物的敏感性有关,stathmin基因高表达,对长春碱药物的敏感性低,宜换用其他药物治疗.     

Stathmin siRNA表达载体的构建及对LM8细胞生物学行为的影响

背景与目的:Stathmin在多种恶性肿瘤细胞中都有高水平表达,通过抑制其表达可以干扰恶性肿瘤细胞的分裂,影响肿瘤细胞的增殖与凋亡。本研究构建并观察stathmin基因RNA干扰表达载体转染LM8细胞系后对stathmin表达及细胞生物学行为的影响。方法:构建靶向stathmin干扰质粒pGenesil-1-Stathmin和通用对照质粒pGenesil-1-HK,以脂质体法将2个重组质粒分别转染骨肉瘤LM8细胞系。实时荧光定量PCR和Western印迹技术检测各组LM8细胞系stathmin在mRNA和蛋白水平的表达,MTT(噻唑蓝)法比色分析检测细胞体外生长抑制率,软琼脂集落形成实验观察单个细胞体外增殖活力,细胞HE染色观察细胞形态学的变化,Hoechst染色观察细胞凋亡特征并计算凋亡率,流式细胞术定量分析细胞周期变化,C3H小鼠移植瘤实验显示肿瘤细胞成瘤能力。结果:DNA测序证实成功构建pGenesil-1-Stathmin重组质粒。转染LM8细胞后,明显抑制stathmin基因表达;细胞体外生长抑制率显著增加;单个细胞体外增殖活力显著下降;细胞HE染色部分细胞呈典型的凋亡细胞形态学改变;Hoechst染色显示细胞凋亡特征,细胞凋亡率明显高于对照组;流式细胞术检测显示细胞周期阻滞于G2/M期,明显高于对照组;C3H小鼠移植瘤实验显示特异转染组致瘤率下降,肿瘤生长减缓。结论:成功构建的靶向干扰质粒pGenesil-1-Stathmin能有效抑制stathmin基因在骨肉瘤LM8细胞的表达并影响其相关生物学行为,其抑制骨肉瘤细胞的增殖与生长,为stathmin基因应用于骨肉瘤的基因治疗研究奠定了理论基础。     

肝细胞癌Paxillin和VEGF的表达及其临床意义

肿瘤的转移和复发受到包括细胞粘附作用和血管形成在内的多种因素的影响.最近发现的桩蛋白(Paxillin)与肿瘤的发生、发展和转移有密切关系[1,2].肿瘤细胞通过分泌多种血管活性物质,促进肿瘤血管的形成,其中以血管内皮生长因子(vascular endothelial growth factor,VEGF)的作用最强、特异性最高,在食管鳞癌、膀胱癌、宫颈癌、结肠腺癌、肾癌等多种人类肿瘤中都有较高水平的表达,且与肿瘤的生长和浸润转移有密切关系[3,4].我们利用免疫组织化学染色的方法,研究肝细胞癌(hepatic cellular carcinoma,HCC)组织中Paxillin和VEGF蛋白的表达及其临床意义.     

E2F陷阱DNA对人肺癌细胞中stathmin mRNA表达的影响及促进肿瘤细胞凋亡的作用

目的：观察转录因子E2F陷阱DNA对stathmin的表达影响及抑制肿瘤细胞增生情况.方法：采用脂质体LipofectamineTM2000将E2F Decoy ODNs转染入人肺癌A549细胞中,用RT-PCR检测转染细胞中stathmin基因mRNA表达水平变化,通过细胞生长曲线观察转染细胞的增殖能力,Tunel法观察转染细胞凋亡情况.结果：E2F Decoy ODNs被成功转染入肿瘤细胞中,RT-PCR检测结果显示实验组stathmin mRNA表达水平明显低于对照组,而且显著抑制了A549细胞的增殖,空白对照组无明显变化,Tunel凋亡染色可见凋亡细胞.结论：E2F Decoy ODNs能特异性下调stathmin mRNA表达,明显抑制A549细胞的增殖,为肿瘤的基因治疗提供了新的手段.     

ezrin与肿瘤及其转移的研究现状

ezrin属紧密连接蛋白家族中的一种主要蛋白,研究显示在多种肿瘤中存在过度表达,通过与细胞黏附分子相互作用、参与信号传导等多种机制,与肿瘤的发生、发展及转移有密切的关系,且已被认为是肿瘤转移的关键调节因子.本文就ezrin的主要特点及其与肿瘤转移关系的研究进展作一综述.     

Stathmin在非小细胞肺癌中的表达及其临床意义

目的：检测stathmin在非小细胞肺癌（ non small cell lung cancer,NSCLC）组织中和正常肺组织中的表达,探讨其与NSCLC临床病理特征之间的关系。方法：免疫组化SP法,检测77例NSCLC组织及20例正常肺组织标本中stathmin蛋白的表达。结果：Stathmin蛋白在NSCLC组织中的阳性表达率为63.7%,显著高于正常肺组织的20.0%,差异具有统计学意义（ P<0.05）。Stathmin的表达与肿瘤的组织学分级、TNM分期、淋巴结转移正相关,差异具有统计学意义（ P<0.05）。结论：Stathmin在NSCLC的发生发展过程中起重要作用,可能成为预测NSCLC诊断及预后的新的生物学及个体化治疗的敏感指标。     

Survivin反义RNA真核表达载体的构建及鉴定

恶性肿瘤无限增殖的主要原因是细胞凋亡调控障碍.Survivin是新近发现的凋亡抑制蛋白家族(inhibitor of apoptosis protein,IAP)成员[1],特异性表达人类多种常见肿瘤中,而不存在于正常成人组织,能抑制caspase活性而发挥抗凋亡作用[2].有研究表明[3-4],应用反义策略阻断survivin表达可提高肿瘤细胞对化疗药物的敏感性,诱导凋亡的发生,已成为肿瘤治疗的新亮点.     

p27(Kip1)-stathmin interaction influences sarcoma cell migration and invasion

Emerging evidences suggest that cyclin-dependent kinase inhibitors (CKIs) can regulate cellular functions other than cell cycle progression, such as differentiation and migration. Here, we report that cytoplasmic expression of p27(kip1) affects microtubule (MT) stability following cell adhesion on extracellular matrix (ECM) constituents. This p27(kip1) activity is due to its ability to bind and impair the function of the MT-destabilizing protein stathmin. Accordingly, upregulation of p27(kip1) or downregulation of stathmin expression results in the inhibition of mesenchymal cell motility. Moreover, high stathmin and low cytoplasmic p27(kip1) expression correlate with the metastatic phenotype of human sarcomas in vivo. This study provides a functional link between proliferation and invasion of tumor cells based on diverse activities of p27(kip1) in different subcellular compartments.     

Stathmin is a Marker of Progression and Poor Prognosis in Esophageal Carcinoma

Stathmin, also called oncoprotein 18, is a founding member of the family of microtubule-destabilizing proteinsthat play a critical role in the regulation of mitosis. At the same time stathmin has been recognized as one ofresponsible factors in cancer cells. The aim of this study was to assess stathmin status, its correlations withclinicopathological parameters and its role as a progosnostic marker in EC patients. The protein and mRNAlevels of stathmin were examined byimmunohistochemistry (IHC) and in situ hybridization in 100EC tissuesand adjacent noncancerous tissues. mRNA and protein expression of stathmin in three EC cell lines(EC9706,ECa109, EC1 commonly used in research) were also analyzed using immunocytochemistry, western blot andin situ hybridization. The prognostic value of Stathmin expression within the tumor tissues were assessed byCox regression and Kaplan-Meier analysis. We showed that stathmin expression was significantly higher in ECtissues than in adjacent noncancerous tissues. High stathmin immunostaining score in the EC was positivelycorrelated with tumor differentiation, Tumor invasion, Lymph node metastases, and TNM stage. In addition, wedemonstrated that three EC cell lines examined, were constitutively expressing a high level of stathmin. Of those,EC-1 showed the strongest mRNA and protein expression for the stathmin analyzed. Kaplan-Meier analysisshowed that significantly longer 5-year survival rate was seen in EC patients with high Stathmin expression,compared to those with low expression of Stathmin expression. Furthermore, multivariate Cox proportionalhazard analyses revealed that Stathmin was an independent factors affecting the overall survival probability.In conclusion, our data provide a basis for the concept that stathmin might be associated with EC developmentand progression.. High levels of Stathmin expression in the tumor tissues may be a good prognostic marker forpatients with EC.     

Stathmin基因在人成骨肉瘤细胞中的表达及意义

stathmin作为细胞信号转导分子在细胞分化及恶性肿瘤发生、发展上发挥重要作用。本研究旨在探讨Stathmin基因在人成骨肉瘤细胞中的表达,并探讨阻断其表达对该肿瘤细胞的生物学行为的影响。方法：RT-PCR及原位杂交法检测2个人成骨肉瘤细胞系及45例人成骨肉瘤组织中Stathmin基因表达情况;以高表达Stathmin基因的人成骨肉瘤细胞系SOSP-9607为靶细胞、反义Stathmin(ASODN)为阻断剂,通过MTT实验观察ASODN对该细胞系的生长抑制作用,并用流式细胞仪分析其对细胞增殖周期的影响。     

Silencing stathmin gene expression by survivin promoter-driven siRNA vector to reverse malignant phenotype of tumor cells

Stathmin gene overexpression has been shown to play an important role in maintenance of malignant phenotype in tumor cells, and the blocking efficacy and tumor specificity of this target has been concerned in clinical trails. In this report, we designed survivin promoter-driven siRNA eukaryotic expression vector that expressed the small interfering RNA targeting stathmin gene to selectively knock down the stathmin gene expression in two different kinds of tumor cell lines while sparing normal cell lines. The therapeutic potential of this recombinant vector was tested in human cervical cancer Hela cells and osteosarcoma SSOP-9607 cells, and in human umbilical vein endothelial cell line ECV304 cells as control. The siRNA vector- transfected Hela cells and SSOP-9607 cells revealed marked inhibition of stathmin expression and a dramatic growth inhibition comparing with ECV304 cells, parental-vector transfected cells and untransfected cells. Cell cycle analysis of siRNA vector transfected tumor cells by Flow Cytometry showed G(2)/M phase block, while morphologic analysis by TURNEL staining method showed marked increase of apoptosis. Our study indicates that survivin gene promoter-driven stathmin siRNA expression vector may have potential use in tumor gene therapy with targeted tumor gene silencing effect.     

Down-regulation of stathmin is required for TGF-beta inducible early gene 1 induced growth inhibition of pancreatic cancer cells

Transforming growth factor-beta (TGF-beta) inducible early gene 1 (TIEG1) is known to induce apoptosis in TGF-beta sensitive pancreatic cancer cells, yet its effect on TGF-beta resistant cancer cells remains unclear. In this study, TIEG1 was found to induce apoptosis in TGF-beta resistant cancer cells and concurrently enhanced gemcitabine chemosensitivity. Down-regulation of stathmin was noted to associate with TIEG1 expression, whilst ectopic overexpression of stathmin prevented TIEG1 mediated growth inhibition of tumor cells. Small interfering RNAs targeting stathmin inhibited pancreatic cancer cell growth. These suggest that stathmin is a downstream target of TIEG1.     

Overexpression of the stathmin gene in a subset of human breast cancer.

Stathmin is a highly conserved cytosolic phosphoprotein that destabilizes microtubules. Stathmin, which has been proposed as a relay protein integrating diverse cell signalling pathways, acts in vitro as a tubulin-sequestering protein, and its activity is dramatically reduced by phosphorylation. Interestingly, stathmin expression and phosphorylation are regulated during the control of cell growth and differentiation, and there is much evidence suggesting that in vivo stathmin plays a role in the control of microtubule dynamics during mitosis. Stathmin may thus be considered as one of the key regulators of cell division. We examined 50 human primary breast tumours for stathmin mRNA and protein expression and screened for abnormalities in the chromosome region harbouring the stathmin gene. Overexpression of stathmin was found in 15 tumours (30%). At the present stage, no clear correlation emerged between stathmin expression and several prognosis markers. Interestingly, perfect matching was observed between stathmin mRNA overexpression, protein overexpression and strong staining for stathmin on paraffin-embedded tumour sections when specimens were available. Furthermore, a tentative link between loss of heterozygosity (LOH) in the 1p32-1pter region and stathmin overexpression was observed. Our results suggest that stathmin might play a role in breast carcinogenesis and that stathmin-overexpressing tumours may represent a new subtype of breast cancer.