STK15基因与恶性肿瘤发生发展的关系

摘要：丝氨酸苏氨酸激酶15（STK15）基因扩增和高表达可引起中心体扩增，染色体不稳定，最终导致细胞的恶性转化。本文综述了STK15基因与恶性肿瘤的关系，对研究STK15基因在肿瘤的发生机制、诊断及治疗中的应用前景等作以阐述并提出了一些尚需探讨的问题。     

STK家族在肿瘤中的研究进展

丝氨酸/苏氨酸蛋白激酶(STK)是蛋白激酶家族的重要成员,其功能是使丝氨酸和苏氨酸残基发生磷酸化,在调节诸如DNA复制、信号转导通路、细胞增殖、细胞分化、细胞死亡及肿瘤发生和发展等重要细胞进程中发挥关键性的作用。STK家族的重要成员主要包括STK15、STK11、STK33与STK31,一些成员的表达与肿瘤的分化及恶性程度有密切关系,有的成员与肿瘤细胞的增殖、侵袭与转移等生物学行为也密切相关。     

STK15过表达对人食管癌细胞株KYSE150生长的影响

 目的：探讨丝氨酸／苏氨酸激酶15 (serine/threonine kinase 15,STK15)过表达对人食管癌细胞株KYSE150生长的影响。方法：采用脂质体法将pEGFP-C1-STK15真核表达载体转染人食管鳞癌细胞株KYSE150,构建STK15过表达的稳定细胞系（GFP-STK15）,通过荧光显微镜和Western blotting检测STK15的表达。采用四甲基偶氮唑蓝（MTT）法观察STK15过表达对体外肿瘤细胞生长的影响。通过流式细胞术分析STK15过表达对细胞周期和凋亡的影响。采用裸鼠致瘤实验观察STK15过表达对体内肿瘤细胞生长的影响。结果：pEGFP-C1-STK15质粒转染细胞后筛选得到稳定克隆,荧光显微镜显示GFP-STK15融合蛋白定位于细胞的中心体以及纺锤体,Western blotting可检测到GFP-STK15 融合蛋白的表达。与对照细胞相比,GFP-STK15细胞系的体外生长能力明显增加;G0/G1期细胞百分率降低,细胞凋亡率减少;GFP-STK15细胞系接种组裸鼠肿瘤明显增大,差异均具有统计学意义（P<0.01）。结论：STK15过表达能促进人食管癌KYSE150细胞的生长,提示STK15将可能成为治疗食管癌的新靶点。     

结肠癌STK15基因表达的病理学分析

目的探讨丝氨酸，苏氨酸激酶15（serine／threonine kinase15，STK15）在结肠癌组织中的表达，以及与临床病理指标间的关系。方法采用免疫组化检测STK15在67例手术切除结肠癌的肿瘤组织及邻近非肿瘤组织中的表达。结果STK15在结肠癌组织中的阳性率为40．29％（27／67），显著高于邻近的非癌组织8．95％（6／67，P〈0．01），STK15基因过表达与结肠癌分化以及浸润深度密切相关（P〈0．05），与其它临床病理指标无关。结论STK15基因可能在结肠癌的发生发展中起相应作用，其过表达程度可作为一新的结肠癌某些生物学行为判定指标。     

双皮质核素钙调素依赖性激酶-1的生物学特点及功能的研究进展

<正>双皮质核素钙调素依赖性激酶-1(DCAMKL-1),属丝氨酸/苏氨酸蛋白激酶,最早在神经系统发育中发现其表达在神经元有丝分裂后期,故又名为微管相关蛋白激酶。近年来的研究表明,DCAMKL-1不仅是胃肠道干细胞的标记物,还是胰干细胞的标记物,并广泛参与了胃肠道肿瘤、组织再生及胰肿瘤等多种     

STK 15基因沉默导致胃癌细胞分裂停滞

目的探讨丝氨酸／苏氨酸激酶15（serine／threonine kinase15,STK15）基因在胃癌细胞有丝分裂中的作用。方法应用RNA干扰技术（RNAi）抑制胃癌细胞株MKN45细胞STK15基因表达;real-time定量PCR及Western blot检测干扰前后STK15 mRNA及蛋白质表达的变化;倒置显微镜观察MKN45细胞形态的变化;流式细胞仪检测细胞周期的变化;MTT法检测细胞增殖速度的变化;免疫荧光结合激光共聚焦显微镜观察MKN45细胞微管及有丝分裂表型的改变。结果STK15基因沉默后。其mRNA及蛋白质表达明显下降,real-time PCR结果显示,转染后48h,STK15^-组STK15 mRNA水平较对照siRNA组的下降了89．54％;Western blot灰度比半定量检测显示,STK15蛋白水平较对照siRNA组降低了57．18％。较多MKN45细胞呈圆形改变并呈现G2期细胞的DNA含量,STK15^-组3个时间点的圆形细胞占18．95％,而对照siRNA组为8．34％,差异有统计学意义（P〈0．05）;流式细胞仪检测结果显示,STK15。组G2期DNA含量细胞平均值为26．13％,而对照siRNA组G2期DNA含量细胞平均值12．46％（P〈0．05）。细胞增殖速度减慢（P〈0．05）。细胞有丝分裂表型发生改变（P〈0．05）。结论STK15基因在MKN45细胞有丝分裂过程中可能起着关键作用,阻断其表达可导致MKN45细胞有丝分裂停滞。     

极体样激酶1与乳腺癌的研究进展

极体样激酶1(PLK1)是一类广泛存在的、高度保守的丝氨酸/苏氨酸蛋白激酶,在启动、维持和完成有丝分裂的过程中发挥着重要作用.学者们发现,PLK1在肿瘤中高表达与肿瘤(尤其是乳腺癌)的生物学行为及预后有密切关系.本文就近年来PLK1与乳腺癌发生发展关系的研究进展进行综述.     

LKB1／STK11研究进展

LKB1 STK1 1基因是PJS患者的主要致病基因 ,为一种肿瘤抑制基因 ,编码一种功能未知的丝氨酸 苏氨酸蛋白激酶。LKB1基因的失活性表达以低频率事件广泛存在于全身多种肿瘤中 ,并在细胞生长抑制和p53依赖性细胞凋亡 ,以及胚胎和血管发育中具有重要作用     

STK17A 基因经TGF-β/ SMAD 信号通路调控宫颈癌细胞增殖凋亡及侵袭的机制研究

目的:探究丝氨酸/苏氨酸激酶17A (STK17A)基因介导转化生长因子β(TGF-β)/SMAD信号通路对宫颈癌细胞增殖、侵袭及凋亡的调控机制。方法:收集我院43例宫颈癌患者癌组织及癌旁组织。HE染色观察组织病理结构。免疫组化检测组织中STK17A阳性表达。筛选STK17A低表达宫颈癌细胞系并将细胞系分为阴性对照组(宫颈癌细胞转染含有无关序列的重组质粒)、基因沉默组(宫颈癌细胞转染含有STK17A shRNA的重组质粒)、基因过表达组(宫颈癌细胞转染含有STK17A片段的重组质粒)、通路抑制剂组(TGF-β/SMAD通路特异性抑制剂处理宫颈癌细胞)、联合组(TGF-β/SMAD通路抑制联合STK17A过表达处理细胞)。qRT-PCR和Western blot检测各组细胞STK17A、TGF-β1、SMAD3、E-cadherin、N-cadherin和TIMP3的表达。CCK-8检测各组细胞活力。细胞划痕和Transwell实验检测各组细胞迁移和侵袭能力。Annexin V-FITC/PI双染检测各组细胞凋亡情况。结果:与癌旁组织相比,宫颈癌组织排列紊乱,无极性(层次和结构)且STK17A低表达。细胞实验中:与阴性对照相比,过表达STK17A或抑制TGF-β/SMAD通路后,TGF-β1、SMAD3、E-cadherin mRNA和蛋白表达下调,但N-cadherin、TIMP3 mRNA和蛋白表达上调(均P0.05)。同时,相对于阴性对照组,过表达STK17A或抑制TGF-β/SMAD通路后,24 h和48 h细胞活力受到明显抑制、细胞侵袭转移能力显著降低且细胞凋亡被显著诱导(均P0.05)。结论:STK17A过表达可能通过抑制TGF-β/SMAD信号通路的活化进而抑制宫颈癌细胞增殖、侵袭同时诱导其凋亡,STK17A有望成为宫颈癌治疗的潜在重要靶点。     

喉癌 STK15基因异常与中心体扩增的研究

目的　研究喉癌中 STK15基因的异常及中心体扩增情况。方法　应用逆转录 -聚合酶链反应方法 ,检测 6 2例喉鳞状细胞癌和人喉鳞状细胞癌细胞系 Hep- 2中 STK15基因 m RNA表达水平 ;应用聚合酶链反应 -单链构象多态性检测上述组织及细胞中 STK15基因第 6、7外显子突变 ;以 Hep- 2细胞系为代表应用免疫荧光方法检测中心体扩增情况。结果　在 39例 ( 6 3% )喉癌及 Hep- 2细胞系中检测到了STK15基因的高表达 ;在上述组织和细胞中均未检测到 STK15基因第 6、7外显子的突变 ;Hep- 2细胞系有明显的中心体扩增 :单个细胞中心体数目变化范围为 1～ 7,有中心体扩增的细胞数为 11%～ 2 3%。结论　在 Hep- 2细胞系中发现了 STK15基因高表达与中心体扩增 ,提示 STK15基因高表达引起中心体扩增 ,可能是导致该细胞系染色体不稳定的重要因素 ;在喉癌组织中观察到了STK15基因高表达 ,提示它可能是导致喉癌发生的多因素之一     

喉癌中STK15基因扩增及表达的研究

目的研究喉癌中5TK15基因扩增、mRNA和蛋白表达增高在喉癌发生、发展中的作用。方法应用差异PCR方法检测40例喉鳞状细胞癌及癌旁正常对照组织5TK15基因扩增的情况；应用逆转录-PCR方法检测同批标本STK15mRNA表达情况；用免疫组织化学方法分析STK15蛋白表达。结果肿瘤组织中5TK15基因扩增率为35％（14／40）；STK15 mRNA表达增高占67．5％（27／40）；STK15蛋白表达的阳性率为72．5％（29／40）；将扩增与表达的结果与喉癌患者的临床各项指标进行统计学分析，5TK15基因扩增、STK15mRNA表达增高与肿瘤的分化程度显著相关（P〈0．05）；STK15蛋白表达与肿瘤的分化程度和病理分级显著相关（P〈0．05）。结论喉癌中5TK15基因扩增、mRNA和蛋白表达水平增高，导致中心体复制异常、染色体不稳定。可能在喉癌的发生及恶性进展中起一定作用。     

Centrosome-, chromosomal-passenger- and cell-cycle-associated mRNAs are differentially regulated in the development of sporadic colorectal cancer

Dysregulation of the centrosome complex and chromosomal segregation has been associated with aneuploid cells and aggressive solid tumours, but the relevance of this mechanism to the adenoma-carcinoma sequence of sporadic colorectal cancer (sCRC), especially tumours showing chromosomal instability (CIN), is still unknown. In a series of matching normal epithelial cells (n = 41), dysplastic cells (n = 18), and invasive carcinoma cells (n = 41) from cases with sCRC, mRNA levels of the centrosomal kinase Aurora-A/STK15 and the chromosomal passenger- and cell cycle-associated molecules Incenp, Survivin, Mad-2, and Cyclin-D1 were therefore measured with specific reference to the type of genetic instability. Compared with normal epithelium, significant up-regulation of mRNAs was already present for Aurora-A/STK15 (p = 0.0313) in dysplastic cells and for all investigated markers in invasive carcinoma. Whereas Aurora-A/STK15 mRNA levels were similarly up-regulated in dysplastic and invasive carcinoma cells (p = 0.0797), Survivin (p = 0.0046) and Cyclin-D1 (p = 0.0017) mRNA levels increased from dysplastic to invasive carcinoma cells. In carcinomas, Incenp mRNA correlated with T category (p = 0.0149), and Survivin (p = 0.0382) and Cyclin-D1 (p = 0.0185) were associated with tumour differentiation. Importantly, a significantly higher (p = 0.0419) fold-change of Aurora-A/STK15 mRNA (p = 0.0419), but not Incenp, Survivin, Mad-2 or Cyclin-D1, was observed in sCRC cases with CIN (n = 29) when compared with tumours showing microsatellite instability (MIN, n = 10). The present data are the first to show an early increase of the centrosomal kinase Aurora-A/STK15 in the adenoma-carcinoma sequence of sCRC. The regulation of this kinase differs in CIN- and MIN-type sCRCs and the pattern of changes is different from those of the cell-cycle-associated markers Survivin, Mad-2, and Cyclin-D1. This reinforces the concept of preferential dysregulation of the centrosome complex in CIN-type (aneuploid), compared with MIN-type, sporadic colorectal cancers and may influence the response to and efficiency of novel therapeutics targeting Aurora kinases.     

Formins regulate the actin-related protein 2/3 complex-independent polarization of the centrosome to the immunological synapse

T cell receptor (TCR)-mediated cytoskeletal reorganization is considered to be actin-related protein (Arp) 2/3 complex dependent. We therefore examined the requirement for Arp2/3- and formin-dependent F-actin nucleation during T cell activation. We demonstrated that without Arp2/3-mediated actin nucleation, stimulated T cells could not form an F-actin-rich lamellipod, but instead produced polarized filopodia-like structures. Moreover, the microtubule-organizing center (MTOC, or centrosome), which rapidly reorients to the immunological synapse through an unknown mechanism, polarized in the absence of Arp2/3. Conversely, the actin-nucleating formins, Diaphanous-1 (DIA1) and Formin-like-1 (FMNL1), did not affect TCR-stimulated F-actin-rich structures, but instead displayed unique patterns of centrosome colocalization and controlled TCR-mediated centrosome polarization. Depletion of FMNL1 or DIA1 in cytotoxic lymphocytes abrogated cell-mediated killing. Altogether, our results have identified Arp2/3 complex-independent cytoskeletal reorganization events in T lymphocytes and indicate that formins are essential cytoskeletal regulators of centrosome polarity in T cells.     

有丝分裂激酶Aurora-A的功能及其与肿瘤发生的关系

有丝分裂激酶Aurora-A具有调节中心体分离、成熟以及纺锤体装配的功能，并且在调节细胞周期G2-M期转变以及checkpoint（监控点）方面发挥重要的作用。近年来研究证实Aurora-A过表达与中心体异常、非整倍体、细胞转化以及肿瘤发生方面存在很大程度的相关性，并通过对抑癌基因p53以及癌基因c-Myc等的调节促进肿瘤的发生。     

Nuclear STK15 expression is associated with aggressive behaviour of oral carcinoma cells in vivo and in vitro

Oral squamous cell carcinoma (OSCC) is one of the most commonly diagnosed cancers worldwide. Chromosome 20q is a hotspot for gene amplification in OSCC and the serine/threonine kinase STK15 (also named Aurora‐A) maps to 20q13. The amplification and over‐expression of STK15 is common in neoplasia but the functional and clinical impact of STK15 in OSCC remains poorly understood. STK15 copy number is amplified in 12% of OSCCs and nuclear STK15 protein expression increases with tumour progression. In vivo elevated nuclear STK15 protein expression is significantly associated with the worse prognosis of OSCC patients. The combination of high nuclear STK15 and Ki‐67 expression has a 2.55‐fold hazard for cancer‐associated mortality. In vitro knockdown of STK15 reduced the oncogenic phenotypes of OECM‐1 cells. Injection of lentivirus carrying shRNA vectors against STK15 significantly reduced the growth of SAS xenografts on nude mice. Knockdown of STK15 also induced autophagy and apoptosis of OSCC cells. Our data provide evidence that STK15 is oncogenic for OSCC and that its nuclear expression is a predictor of clinical behaviour. Knockdown of STK15 could be a potential therapeutic option in OSCC and other tumours. Copyright © 2010 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.     

Loss of γ-tubulin,GCP-WD/NEDD1 and CDK5RAP2 from the Centrosome of Neurons in Developing Mouse Cerebral and Cerebellar Cortex

It has been recently reported that the centrosome of neurons does not have microtubule nucleating activity. Microtubule nucleation requires γ-tubulin as well as its recruiting proteins, GCP-WD/NEDD1 and CDK5RAP2 that anchor γ-tubulin to the centrosome. Change in the localization of these proteins during in vivo development of brain, however, has not been well examined. In this study we investigate the localization of γ-tubulin, GCP-WD and CDK5RAP2 in developing cerebral and cerebellar cortex with immunofluorescence. We found that γ-tubulin and its recruiting proteins were localized at centrosomes of immature neurons, while they were lost at centrosomes in mature neurons. This indicated that the loss of microtubule nucleating activity at the centrosome of neurons is due to the loss of γ-tubulin-recruiting proteins from the centrosome. RT-PCR analysis revealed that these proteins are still expressed after birth, suggesting that they have a role in microtubule generation in cell body and dendrites of mature neurons. Microtubule regrowth experiments on cultured mature neurons showed that microtubules are nucleated not at the centrosome but within dendrites. These data indicated the translocation of microtubule-organizing activity from the centrosome to dendrites during maturation of neurons, which would explain the mixed polarity of microtubules in dendrites.