S100A9在肿瘤方面的研究进展

S100A9是钙结合蛋白8100蛋白家族中重要的成员之一,其参与炎症反应、调节细胞生长分化、生长抑制、诱导细胞凋亡等,近年来研究发现S100A9时肿瘤的生长、增殖及侵袭有着重要作用,可能会成为肿瘤诊治的新靶点.基于上述思路,本文拟对S100A9与肿瘤的关系进行简要综述.     

S100A11的表达及其与胃癌的关系

目的:探讨S100A11在胃癌和正常胃粘膜组织中的表达及意义.方法:采用RT-PCR和Western Blot技术检测21对配对胃癌组织和正常胃粘膜组织中S100A11的表达情况.结果:胃癌组织S100A11 mRNA的表达量(1.26±0.03)高于正常胃癌粘膜组织中的表达量(0.75±0.04),两组比较差异有统计学意义(p＜0.05).S100A11蛋白在胃癌组织中的表达量(0.94±0.05)明显高于在正常胃粘膜组织中的表达量(0.39±0.05),两组比较差异有统计学意义(p＜0.05).结论:S100A11在胃癌组织中的表达量明显高于正常组织,提示其与胃癌的发生和发展有关.     

S100A4原核表达载体的构建以及蛋白的表达和纯化

S100A4是S100蛋白家族的成员,在细胞的增殖、分化、损伤修复以及肿瘤细胞转移等方面发挥重要的调控作用.本研究将S100A4全长基因构建到pET28a原核表达载体上,利用大肠杆菌表达系统表达和纯化出高纯度的重组人S100A4.通过试验证明,重组人S100A4蛋白在体外可以有效地增强黑色素瘤细胞A375-S2的增殖.重组人S100A4原核表达与纯化方法的建立将促进其结构和生物学功能研究,并且对于S100蛋白家族其它蛋白的表达与纯化具有重要的参考意义.     

S100A4在子宫内膜癌中的表达及其临床病理意义

目的:检测S100A4在子宫内膜癌中的表达并分析其与子宫内膜癌临床病理指标的相关性,为子宫内膜癌的临床诊断、治疗及与预后预测提供参考依据。方法:采用免疫组织化学技术检测比较70例子宫内膜癌和40例正常子宫内膜组织中S100A4的表达,并分析子宫内膜癌组织中S100A4的表达与患者临床病理指标和生存期的相关性。结果:70例子宫内膜癌组织中S100A4的阳性表达率为57.14%(40/70),40例正常子宫内膜组织中S100A4的阳性表达率为10%(4/40),显著低于子宫内膜癌组织(P0.05)。子宫内膜癌组织中S100A4的表达与患者的年龄和淋巴结转移无显著相关,但与肿块浸润子宫肌壁深度、分化程度、临床分期均呈显著相关(P0.05)。S100A4呈阳性表达的子宫内膜癌患者的生存率和生存期均较S100A4呈阴性表达病例显著降低或缩短(P=0.01)。结论:子宫内膜癌组织中S100A4呈异常高表达,与子宫内膜癌的发生发展和预后密切相关,可能作为子宫内膜癌诊断和预后预测的参考标志物。     

S100A8通过自噬促进B细胞淋巴瘤耐药性的机制研究

B细胞淋巴瘤是起源于淋巴造血系统的恶性肿瘤,是由分化过程中淋巴细胞恶性转化的复杂过程引起的。B细胞淋巴瘤细胞的耐药性是制约B细胞淋巴瘤治疗的关键因素。自噬是细胞成分降解和再循环的重要细胞生物学过程,近年来其与肿瘤耐药性的相关性受到越来越多的关注。S100A8是钙结合蛋白S100家族的重要成员,其在淋巴瘤的的耐药调控中发挥重要作用,但具体机制尚不清楚。在该研究中,以人Burkitt淋巴瘤细胞Daudi、人B淋巴瘤细胞SUDHL-4和人套细胞淋巴瘤细胞JeKo-1为研究对象,揭示了B细胞淋巴瘤细胞的耐药性与S100A8的表达水平密切相关,且S100A8可以显著激活淋巴瘤细胞的自噬进程。慢病毒感染稳定敲低S100A8的表达后,一方面,淋巴瘤细胞内质网和线粒体内的BNIP3蛋白的表达水平显著降低,自噬受到抑制;另一方面,自噬起始复合物BECN1-PI3KC3的表达显著降低,而BCL2与BECN1的结合显著增多,进而抑制细胞自噬。     

新生隐球菌共孵育后小鼠脑血管内皮细胞S100A10基因的表达水平变化

目的探讨S100A10基因在新生隐球菌感染脑血管内皮细胞中的作用。方法将新生隐球菌H99株与小鼠脑血管内皮细胞共孵育后,不同时间终止共孵育,提取小鼠脑血管内皮细胞的总RNA,采用实时定量荧光PCR检测S100A10的表达水平。结果在与新生隐球菌共孵育2h后,小鼠脑血管内皮细胞中的S100A10基因表达水平随着共孵育时间的延长而升高（P〈0.05）。结论S100A10基因在新生隐球菌对中枢神经系统的易感性存在一定的作用。     

S100A4基因在结肠癌中的表达及意义

目的：通过检测S100A4基因在结肠癌细胞系及结肠癌组织中的表达,探讨其与结肠癌的关系。方法：运用RT-PCR法检测不同结肠癌细胞系中S100A4基因的表达情况;通过原位杂交和免疫组化方法检测61例结肠癌标本中S100A4基因的表达。结果：结肠癌细胞系Lovo及HT29均有S100A4基因表达。S100A4蛋白和RNA在结肠癌中表达率分别为36．1％和34.4％,而在正常结肠组织中不表达（p〈0．05）。临床分期晚比临床分期早的患者S100A4表达明显增高（p〈0.05）;有淋巴结转移的患者比无淋巴结转移的患者S100A4表达明显增高（p〈0．05）。此外,S100A4表达还与肿瘤大小,病理学分级,肉眼分型等相关。结论：结肠癌中S100A4基因表达增高,而且与肿瘤的侵袭及转移密切相关,是判断结肠癌生物学行为及预后的有价值的指标。     

S100A9参与乙型肝炎病毒X蛋白介导的HepG2细胞增殖与迁移

目的:探讨S100A9在乙型肝炎病毒X(HBx)介导的HepG2细胞增殖及迁移中的作用。方法:用表达HBx蛋白的重组腺病毒AdHBx感染HepG2细胞后,用CCK-8实验检测细胞增殖能力及划痕愈合实验检测细胞迁移能力;在HepG2/AdHBx细胞中转染S100A9-siRNA及其对照siRNA后,检测HepG2细胞增殖及迁移能力;在HepG2/Ad HBx和对照组HepG2/AdGFP细胞中,采用Real-time PCR及Western Blot检测S100A9基因及蛋白的表达情况;在HepG2/AdHBx细胞中,加入不同剂量的NF-κB抑制剂BAY11-7082后,检测各组中S100A9的基因及蛋白表达情况。结果:HBx促进HepG2细胞的增殖与迁移; S100A9-siRNA抑制S100A9的表达后,HBx促进HepG2细胞的增殖与迁移的作用降低,HBx介导的HepG2细胞的增殖与迁移部分依赖于S100A9; S100A9基因及蛋白表达在HepG2/AdHBx中较对照组HepG2/Ad GFP显著升高,HBx可致S100A9表达增加;抑制NF-κB转录活性后,AdHBx+BAY11-7082组S100A9基因及蛋白表达较对照组显著降低,阻断NF-κB转录活性可部分抑制HBx调控的S100A9表达。结论:HBx可调控S100A9的表达且与NF-κB活化有关,S100A9参与HBx介导的HepG2细胞的增殖与迁移。     

S100A4 在胰腺癌中的研究进展

胰腺癌最重要的生物学特性是容易发生转移和侵袭,致使很多患者无法得到根治性治疗。外科手术是胰腺癌惟一可能治愈的手段,但仅有10-20%的患者有机会手术治疗。错过早期诊断、常规疗法普遍不明显及快速肿瘤扩散共同导致患者的预后不良。胰腺癌的发生、发展受多基因调控。S100A4基因是近几年发现的一种具有促肿瘤作用的基因,目前研究认为该蛋白在胰腺癌的侵袭和转移中起重要作用.本文主要就S100A4与胰腺癌的有关研究进展加以综述。     

S100A4在胰腺癌中的研究进展

胰腺癌最重要的生物学特性是容易发生转移和侵袭,致使很多患者无法得到根治性治疗。外科手术是胰腺癌惟一可能治愈的手段,但仅有10-20%的患者有机会手术治疗。错过早期诊断、常规疗法普遍不明显及快速肿瘤扩散共同导致患者的预后不良。胰腺癌的发生、发展受多基因调控。S100A4基因是近几年发现的一种具有促肿瘤作用的基因,目前研究认为该蛋白在胰腺癌的侵袭和转移中起重要作用.本文主要就S100A4与胰腺癌的有关研究进展加以综述。     

The expression of S100A8 in pancreatic cancer-associated monocytes is associated with the Smad4 status of pancreatic cancer cells

The cross-talk between tumour cells and the surrounding supporting host cells (stroma) is a key regulator of cancer growth and progression. By undertaking 2-DE analysis of laser capture microdissected malignant and stromal components of pancreatic tumours and benign ductal elements, we have identified high levels of S100A8 and S100A9 in tumour-associated stroma but not in benign or malignant epithelia. Immunohistochemical analysis (n = 71 patients) revealed strong expression of both proteins in stromal myeloid cells, subsequently identified as CD14(+)/CD68(- )monocytes/macrophages. Co-immunofluorescence revealed that S100A8 was expressed in a subset of S100A9-positive cells. Correlation of the expression of S100A8 and S100A9 to patient parameters revealed that the microenvironments of tumours which lacked expression of the tumour suppressor protein, Smad4, had significantly reduced numbers of S100A8-immunoreactive (p = 0.023) but not S100A9-immunoreactive (p = 0.21) cells. The ratio of S100A8- to S100A9-positive cells within individual tumours was significantly lower in Smad4-negative tumours than in Smad4-positive tumours (p<0.003). Pancreatitic specimens also contained S100A8- and S100A9-expressing cells, although this was not observed in regions displaying extensive fibrosis. In conclusion, our study provides an extensive analysis of S100A8 and S100A9 in pancreatic disease and highlights a potentially important relationship between pancreatic cancer cells and their surrounding microenvironment.     

S100A8 and S100A9 activate MAP kinase and NF-kappaB signaling pathways and trigger translocation of RAGE in human prostate cancer cells

S100 proteins, a multigenic family of calcium-binding proteins, have been linked to human pathologies in recent years. Deregulated expression of S100 proteins, including S100A8 and S100A9, was reported in association with neoplastic disorders. In a previous study, we identified enhanced expression of S100A8 and S100A9 in human prostate cancer. To investigate potential functional implications of S100A8 and S100A9 in prostate cancer, we examined the influence of over-expressed and of purified recombinant S100A8 and S100A9 proteins in different prostate epithelial cell lines. S100A8 and S100A9 were secreted by prostate cancer cells, a finding which prompted us to analyze a possible function as extracellular ligands. S100A8/A9 induced the activation of NF-kappaB and an increased phosphorylation of p38 and p44/42 MAP kinases. In addition, extracellular S100A8/A9 stimulated migration of benign prostatic cells in vitro. Furthermore, in immunofluorescence experiments, we found a strong speckled co-localization of intracellular S100A8/A9 with RAGE after stimulating cells with recombinant S100A8/A9 protein or by increasing cytosolic Ca2+ levels. In summary, our findings show that S100A8 and S100A9 are linked to the activation of important features of prostate cancer cells.     

S100 proteins in cartilage: Role in arthritis

S100 proteins are low molecular weight calcium binding proteins expressed in vertebrates. The family constitutes 21 known members that are expressed in several tissues and cell types and play a major role in various cellular functions. Uniquely, members of the S100 family have both intracellular and extracellular functions. Several members of the S100 family (S100A1, S100A2, S100A4, S1008, S100A9, S100A11, and S100B) have been identified in human articular cartilage, and their expression is upregulated in diseased tissue. These S100 proteins elicit a catabolic signaling pathway via receptor for advanced glycation end products (RAGE) in cartilage and may promote progression of arthritis. This review summarizes our current understanding of the role of S100 proteins in cartilage biology and in the development of arthritis.     

钙结合蛋白S100A14的结构预测及分析

钙结合蛋白S100A14是S100家族中的新成员,其空间结构与功能尚未阐明。采用服务器PredictProtein对人S100A14进行二级结构预测,利用同源建模法构建S100A14（序列12-102）的空间结构模型,经PROCHECK评估模型的可靠性,并将所构建的单体模型进行分子对接,预测S100A14形成同源二聚体的可能性及模式。结果显示,S100A14与S100A13的蛋白序列一致性最高,其C-端Ca2＋结合区存在多个变异,但Cu2＋和Zn2＋结合位点保守存在;helix I与helix IV较S100A13延伸长,而helix I、helix II和helix IV与S100A13的四个α螺旋一样具有两亲性的结构特征,并且在S100A13中扮演重要角色的W77在S100A14的helix IV（W85）中也保守存在。空间结构上,S100A14与S100A13具极大相似性;分子对接显示S100A14单体间可以通过疏水作用力形成＂X-型螺旋束＂同源二聚体。这些结构特征的分析将为S100A14的功能研究提供重要线索。     

Genomic and phylogenetic analysis of the S100A7 (Psoriasin) gene duplications within the region of the S100 gene cluster on human chromosome 1q21

Abstract The human S100 gene family encodes the EF-hand superfamily of calcium-binding proteins, with at least 14 family members clustered relatively closely together on chromosome 1q21. We have analyzed the most recently available genomic sequence of the human S100 gene cluster for evidence of tandem gene duplications during primate evolutionary history. The sequences obtained from both GenBank and GoldenPath were analyzed in detail using various comparative sequence analysis tools. We found that of the S100A genes clustered relatively closely together within a genomic region of 260 kb, only the S100A7 (psoriasin) gene region showed evidence of recent duplications. The S100A7 gene duplicated region is composed of three distinct genomic regions, 33, 11, and 31 kb, respectively, that together harbor at least five identifiable S100A7-like genes. Regions 1 and 3 are in opposite orientation to each other, but each region carries two S100A7-like genes separated by an 11-kb intergenic region (region 2) that has only one S100A7-like gene, providing limited sequence resemblance to regions 1 and 3. The duplicated genomic regions 1 and 3 share a number of different retroelements including five Alu subfamily members that serve as molecular clocks. The shared (paralogous) Alu S insertions suggest that regions 1 and 3 were probably duplicated during or after the phase of AluS amplification some 30–40 mya. We used PCR to amplify an indel within intron 1 of the S100A7a and S100A7c genes that gave the same two expected product sizes using 40 human DNA samples and 1 chimpanzee sample, therefore confirming the presence of the region 1 and 3 duplication in these species. Comparative genomic analysis of the other S100 gene members shows no similarity between intergenic regions, suggesting that they diverged long before the emergence of the primates. This view was supported by the phylogenetic analysis of different human S100 proteins including the human S100A7 protein members. The S100A7 protein, also known as psoriasin, has important functions as a mediator and regulator in skin differentiation and disease (psoriasis), in breast cancer, and as a chemotactic factor for inflammatory cells. This is the first report of five copies of the S100A7 gene in the human genome, which may impact on our understanding of the possible dose effects of these genes in inflammation and normal skin development and pathogenesis.     

The hetero-oligomeric complex of the S100A8/S100A9 protein is extremely protease resistant

S100A8, S100A9 and S100A12 proteins are associated with inflammation and tissue remodelling, both processes known to be associated with high protease activity. Here, we report that homo-oligomeric forms of S100A8 and S100A9 are readily degraded by proteases, but that the preferred hetero-oligomeric S100A8/A9 complex displays a high resistance even against proteinase K degradation. S100A12 is not as protease resistant as the S100A8/A9 complex. Since specific functions have been assigned to the homo- and heterooligomeric forms of the S100A8 and A9 proteins, this finding may point to a post-translational level of regulation of the various functions of these proteins in inflammation and tissue remodelling.     

S100A8/S100A9 and their association with cartilage and bone

S100A8 and S100A9 are calcium-binding proteins expressed in myeloid cells and are markers of numerous inflammatory diseases in humans. S100A9 has been associated with dystrophic calcification in human atherosclerosis. Here we demonstrate S100A8 and S100A9 expression in murine and human bone and cartilage cells. Only S100A8 was seen in preosteogenic cells whereas osteoblasts had variable, but generally weak expression of both proteins. In keeping with their reported high-mRNA expression, S100A8 and S100A9 were prominent in osteoclasts. S100A8 was expressed in alkaline phosphatase-positive hypertrophic chondrocytes, but not in proliferating chondrocytes within the growth plate where the cartilaginous matrix was calcifying. S100A9 was only evident in the invading vascular osteogenic tissue penetrating the degenerating chondrocytic zone adjacent to the primary spongiosa, where S100A8 was also expressed. Whilst, S100A8 has been shown to be associated with osteoblast differentiation, both S100A8 and S100A9 may contribute to calcification of the cartilage matrix and its replacement with trabecular bone, and to regulation of redox in bone resorption.