趋化因子CXCL13及其受体CXCR5研究进展

趋化因子及其受体是免疫系统的重要组成部分,通过它们之间的信号传导,使得免疫系统正常运作.根据其结构特征,趋化因子及其受体被分为C、CC、CXC、CX3C四个家族,本文将介绍近两年对CXC家族的趋化因子CXCL13的结构特征、表达调控、与细胞因子家族其它成员之间的相互作用,以及它与相应的配体CXCR5结合后所介导的生理和病理作用等方面研究的一些进展,为今后的研究工作提供帮助.     

趋化因子及其受体CXCL12/CXCR4在人前列腺癌转移机制中的作用

目的 探讨趋化因子及其受体CXCL12/CXCR4在人前列腺癌转移机制中的作用.方法 免疫组织化学技术分析CXCL12/CXCR4蛋白在18例前列腺癌组织中的表达;免疫细胞化学技术分析CXCL12/CXCR4蛋白在人前列腺癌细胞株PC3、DU145和LNCap中的表达;迁移、侵袭试验分析外源性CXCL12对PC3、DU145和LNCap体外侵袭能力的调节作用.结果 18例人前列腺癌组织中,17例不同强度表达CXCR4蛋白,1例阴性表达,同时除1例标本弱表达CXCL12蛋白外,其余不表达CXCL12蛋白.3种前列腺癌细胞株均表达CXCR4蛋白,不表达CXCL12蛋白.外源性CXCLl2可明显促进PC3、DU145及LNCap的体外迁移、侵袭,以抗CXCL12或CXCR4抗体预处理PC3、LNCap细胞可以拮抗CXCL12对它们的促迁移、侵袭作用.结论 人前列腺癌组织表达CXCR4蛋白,CXCL12/CXCR4信号通路可能参与前列腺癌的侵袭、转移.     

CXCL12/CXCR4在胶质瘤侵袭性生长中的作用

胶质瘤是中枢神经系统最常见的肿瘤,约占成人颅内肿瘤的45％-60％,呈侵袭性生长并且术后容易复发,病死率较高。随着分子病理学的发展,对胶质瘤细胞的表面受体、趋化因子、生长因子、癌基因、抑癌基因等的变化及其引起的信号转导和效应都有了进一步的认识。研究表明趋化因子及其受体在乳腺癌、卵巢癌等多种肿瘤有表达,与肿瘤的生长、侵袭、转移、血管形成存在密切关系,其中CXCL12／CX—CR4生物学轴（CXCL12／CXCR4 biological axis）在肿瘤发生发展中起主要作用。现将CXCL12／CXCR4在脑胶质瘤侵袭性生长中作用的研究进展综述如下。     

CXCL16趋化因子在小鼠免疫性肝损伤中的作用

目的：研究CXCL16在免疫性肝脏损伤中的表达及其功能。方法：运用实时定量PCR检测CXCL16在小鼠肝损伤模型中的表达变化；通过特异中和抗体的体内阻断CXCL16功能实验，观察ALT水平、肝脏病理变化、TNF-a和FasL凋亡基因表达、肝脏内浸润淋巴细胞及其主要T细胞亚群的数量变化以及小鼠存活率等指标，研究CXCL16在肝脏炎症和损伤中的作用，并初步探讨它的可能机理。结论：肝脏组织中CXCL16的上调表达介导了特异性淋巴细胞向肝脏局部组织的趋化和募集，并协同调节其它相关分子的表达，参与肝组织损伤。     

趋化因子受体CXCR4在人肺癌高转移细胞株的表达和意义

目的：以人肺癌高、低转移细胞株95D、95C为研究对象，研究趋化因子受体CXCR4的表达及其在肿瘤细胞体外转移潜能中的作用和意义。方法：采用RT-PCR检测95D、95C细胞CXCR4 mRNA的表达情况；以PMA活化肿瘤细胞，研究CXCR4 mRNA表达水平与细胞活性状态的关系；应用钙离子内流实验验证其表达是否具有功能；通过趋化实验观察CXCR4特异性配件SDF-α和裸鼠组织匀浆液对95D细胞的趋化迁移作用；通过MTT法测定95D细胞对SDF-1α作用的增殖反应。结果：95D细胞功能性地高表达趋化因子受体CXCR4，且其表达水平与细胞活性状态有关；CXCR4特异性配件SDF-1α和裸鼠肺、淋巴结组织匀浆均可在体外趋化95D细胞的迁移，SDF-1α还可促进95D细胞的增殖。结论：95D细胞功能性高表达趋化因子受体CXCR4可能与人肺癌细胞株95D的体外高转移潜能有关。     

CXCL16/CXCR6与炎症性疾病

多种临床疾病(包括肿瘤的发生)与炎症相关,因而趋化因子及其受体愈来愈受到广泛关注.近年有研究发现:人CXC型趋化因子配体16(CXC chemokine ligand 16,CXCL16)及其受体CXC型趋化因子受体6 (CXC chemokine receptor 6,CXCR6)在肾炎、肺部疾患、动脉粥样硬化、冠状动脉疾病、类风湿性关节炎等多种炎症性病变组织中表达;并且,在前列腺癌、结肠癌、乳腺癌等炎症相关肿瘤的肿瘤细胞或浸润性淋巴细胞上也有表达.CXCL16通过CXCR6介导免疫细胞向病变组织趋化,影响疾病转归,甚至参与肿瘤细胞增殖或血管生成.对CXCL16/CXCR6的深入研究,将为炎症性疾病的诊断和炎症相关肿瘤的预后提供参考.     

CXCL8及其受体CXCR1、CXCR2在慢性乙肝患者外周血PMNs中的表达

目的:探讨慢性乙肝患者外周血中性粒细胞(PMNs)上CXCL8及其受体CXCR1、CXCR2的表达。方法:以中性粒细胞分离液分离、纯化PMNs,检测患者血清HBe Ag及PMNs内HBV DNA,入选患者依据检测结果进行分组,SABC免疫细胞化学染色法检测各组患者PMNs内CXCL8及其受体CXCR1、CXCR2的表达。结果:SABC免疫细胞化学染色结果显示,CXCL8主要位于PMNs胞浆中,CXCR1、CXCR2多见于胞浆和胞膜上。其中HBe Ag(+)者CXCL8、CXCR1免疫着色较深,而CXCR2免疫着色较浅;PMNs内HBV DNA(+)者CXCL8、CXCR1免疫着色亦较深,而CXCR2免疫着色亦较浅。患者CXCL8和CXCR1的水平均显著升高,与正常对照相比,差异均有显著性(P0.05),而CXCR2的表达无统计学意义(P0.05)。结论:HBV侵染中性粒细胞后可促进CXCL8分泌,使胞膜CXCR1表达进一步增强。CXCL8、CXCR1、CXCR2免疫组化染色程度与患者HBe Ag表达、HBV DNA载量密切相关。高表达CXCR1的中性粒细胞与CXCL8相互作用,趋化吸引更多PMNs至病灶,参与局部炎性损伤和组织修复。     

趋化因子受体CXCR4在胃癌颈部转移淋巴结中表达的研究

目的 研究趋化因子受体CXCR4在胃癌转移性淋巴结中表达的情况。方法 应用免疫组化的方法研究胃癌病人颈部转移性淋巴结（实验组）和非转移性淋巴结（对照组）CXCR4的表达情况。 结果 实验组CXCR4的阳性率为98.1％,与对照组比较差异显著。 结论 CXCR4在胃癌的转移过程中有重要的作用。     

趋化因子CXCL12及其配体CXCR4、CXCR7对HER2阳性乳腺癌细胞生物学功能的影响北大核心CSCD

目的:探究趋化因子CXCL12及其配体CXCR4、CXCR7对HER2阳性乳腺癌细胞增殖、细胞周期、迁移、侵袭和上皮-间质转化(EMT)的影响。方法:体外培养HER2阳性乳腺癌细胞BT474,应用siRNA转染技术单独或联合沉默CXCR4、CXCR7,RT-PCR与Western blot检测转染效率;应用CXCL12刺激上述转染细胞,并将其分为5组,A组:正常培养的BT474细胞;B组:CXCL12处理的BT474细胞;C组:CXCL12处理的转染si-CXCR4细胞;D组:CXCL12处理的转染si-CXCR7细胞;E组:CXCL12处理的联合转染si-CXCR4与si-CXCR7细胞;应用CCK-8、流式细胞术、划痕实验、侵袭实验及Western blot分别检测沉默CXCR4和(或)CXCR7对CXCL12诱导的乳腺癌细胞增殖、细胞周期进展、迁移、侵袭和EMT行为的影响。结果:转染siRNA能显著降低BT474细胞中CXCR4和(或)CXCR7的mRNA和蛋白表达水平(P<0.01);单独或联合沉默CXCR4与CXCR7均能明显抑制CXCL12对乳腺癌细胞增殖、细胞周期进展、迁移、侵袭行为的促进作用(P<0.05或P<0.01),并以联合沉默CXCR4与CXCR7时效果最为显著(P<0.01),与单独沉默CXCR7相比,沉默CXCR4更能抑制CXCL12对乳腺癌EMT的促进(P<0.05)。结论:沉默CXCR4或CXCR7表达均能抑制CXCL12对HER2阳性乳腺癌细胞增殖、细胞周期进展、迁移、侵袭的促进功能,但CXCL12主要通过与CXCR4相互作用来促进乳腺癌的EMT行为,而同时抑制CXCR4或CXCR7能更有效地抑制CXCL12的上述功能。     

幼年特发性关节炎患儿关节滑膜组织中趋化因子CXCL10及其受体CXCR3的表达及意义

目的检测趋化因子CXCL10及其受体CXCR3在幼年特发性关节炎(JIA)患儿关节滑膜组织中的表达,探讨其在JIA发病机制中的作用。方法通过免疫组织化学方法,检测12例JIA患儿和4例非JIA患儿关节滑膜组织中CXCL10和CXCR3的表达;通过半定量RT-PCR方法,检测CXCR3在JIA患儿和对照幼儿关节滑膜组织中mRNA水平的表达。结果免疫组织化学结果表明,CXCL10/CXCR3在JIA患儿及对照组阳性表达差异有显著性(P0.05);CXCR3在JIA患儿关节滑膜组织中mRNA表达水平(CXCR3∶GAPDH为2.26±1.55)显著高于对照组(0.66±0.44),两者差异有显著性(P0.05)。结论趋化因子CXCL10及其受体CXCR3在幼年特发性关节炎(JIA)的发病中可能起到了重要的作用。     

The CXCR4/CXCL12 axis in endometrial cancer

Chemokines and their receptors seem to act as important regulators of the metastatic cascade. CXCL12 and its receptor CXCR4 were shown to be involved in human cancer progression. There is increasing evidences suggesting that the expression of CXCR4 in human cancers is correlated with poor patient prognosis and that CXCR4 neutralization can prevent metastases in vivo. Here we tested the role of the CXCR4/CXCL12 axis in a neoplasia with a reduced risk of metastatic progression, such as human endometrial cancer. CXCR4 and CXCL12 mRNA expression was measured in 41 endometrial cancers and in corresponding not affected tissues. The expression of CXCR4 was predominant in endometrial cancer (P = 0.035) whereas CXCL12 was overexpressed in normal mucosae (P = 0.002). CXCR4 expression (P = 0.035), but not CXCL12, was significantly related to cancer differentiation. Endometrial cancer cells (HEC1A) were able to generate diffuse metastases in peritoneum, lung and liver of CD-1 nude mice, but the simultaneous treatment with a neutralizing anti-CXCR4 monoclonal antibody dramatically reduced the number and the size of metastases in the animals. In conclusion, our data seem to indicate that the CXCR4-CXCL12 axis can play a role in the progression of endometrial carcinoma and that specific therapies with antagonists of chemokines receptors could be of help in the treatment of metastatic patients.     

New insights on the role of CXCR4 in cancer metastasis

The evolutionarily conserved chemokine superfamily encodes small peptide molecules that bind G-protein-coupled receptors. In humans, this superfamily includes at least 46 ligands and 18 receptors. In general, chemokines and their receptors form a chemotactic network that regulates the migration of cells to specific micro-anatomical destinations within an organism in an organized and non-random manner. Recent studies place chemokine-chemokine receptor pairs at the centre of not only physiological cell migration, but also pathological processes such as metastasis. This mini review considers some recent data on how chemokines regulate tumour cells during metastasis. These observations suggest novel ways for pharmacological intervention.     

HPV16/18和HPV16E6/E7DNA在宫颈癌组织中的表达

目的检测HPV16/18和HPV16E6/E7 DNA在宫颈癌组织中的表达,探讨其在宫颈癌发病中的作用.方法应用PCR和琼脂糖凝胶电泳方法检测46例宫颈癌组织中HPV16/18和HPV16E6/E7DNA.结果 46例宫颈癌中56.5%(26/46)扩增HPV16/18 DNA,其中宫颈鳞癌25例,宫颈腺癌1例.正常对照组20例HPV16/18DNA均为阴性,与宫颈癌组相比差异有显著性(P<0.01).HPV16/18 DNA阳性拷贝对数值为4.32±2.45.HPV16E6,E7DNA分别有53.8%(14/26)、46.2%(12/26)扩增.结论 HPV16/18和HPV16E6/E7 DNA与宫颈癌的发生密切相关,是宫颈癌恶性转化的关键之一,预示着宫颈癌有较强的增殖能力和转移能力.     

Site-directed mutagenesis of the chemokine receptor CXCR6 suggests a novel paradigm for interactions with the ligand CXCL16

Chemokine receptor CXCR6 mediates the chemotaxis and adhesion of leukocytes to soluble and membrane-anchored forms of CXCL16, and is an HIV-1 co-receptor. Here, we describe the effects of mutation of acidic extracellular CXCR6 residues on receptor function. Although most CXCR6 mutants examined were expressed at levels similar to wild-type (WT) CXCR6, an N-terminal E3Q mutant was poorly expressed, which may explain previously reported protective effects of a similar single nucleotide polymorphism, with respect to late-stage HIV-1 infection. In contrast to several other chemokine receptors, mutation of the CXCR6 N terminus and inhibition of post-translational modifications of this region were without effect on receptor function. Likewise, N-terminal extension of CXCL16 resulted in a protein with decent potency and efficacy in chemotaxis and not, as anticipated, a CXCR6 antagonist. D176N and E274Q CXCR6 mutants were unable to interact with soluble CXCL16, suggesting a critical role for D176 and E274 in ligand binding. Intriguingly, although unable to interact with soluble CXCL16, the E274Q mutant could promote robust adhesion to membrane-anchored CXCL16, suggesting that soluble and membrane-bound forms of CXCL16 possess distinct conformations. Collectively, our data suggest a novel paradigm for the CXCR6:CXCL16 interaction, a finding which may impact the discovery of small-molecule antagonists of CXCR6.     

CXCL12(SDF-1)-CXCR4及CXCL12-CXCR7与胃癌相关性研究进展

胃癌是最常见的恶性肿瘤之一,远处转移是其预后不良的主要原因.既往研究认为CX-CR4是趋化因子CXCL12的唯一受体,CXCL12/CXCR4轴在胃癌的发生发展过程中起着重要作用,然而最近研究表明CXCL12尚存在CXCR7这一新的受体,并且CXCL12/CXCR7轴同样对肿瘤的发生发展起重要作用.     

肺癌CDKN2/p16基因纯合缺失的研究

目的　研究 Ｃ Ｄ Ｋ Ｎ２／ｐ１６ 基因的缺失与肺癌发生、发展的关系。方法　采用多重聚合酶链反应技术,对８９ 例肺癌进行了 Ｃ Ｄ Ｋ Ｎ２／ｐ１６ 基因第１ 、２ 外显子纯合缺失的分析研究。结果　标本取材方法的改良提高了聚合酶链反应技术对基因缺失的检出率,８９ 例肺癌中检出第１ 外显子缺失率１９ ．１ ％ （１７／８９） ,第２ 外显子缺失率２２ ．５ ％ （２０／８９） ,有１４ 例第１ 、２ 外显子共同缺失,第１ 或（ 和） 第２ 外显子总缺失率为２５８ ％ （２３／８９） 。 Ｃ Ｄ Ｋ Ｎ２／ｐ１６ 基因的缺失集中发生于非小细胞肺癌, 并与转移和分期有关。结论 Ｃ Ｄ Ｋ Ｎ２／ｐ１６ 基因的缺失是非小细胞肺癌的遗传易感因素,并在其恶性进展中起一定作用。     

Co-expression of uPAR and CXCR4 promotes tumor growth and metastasis in small cell lung cancer

Urokinase-type plasminogen activator receptor (uPAR) and C-X-C-chemokine receptor-4 (CXCR4) are considered as key molecules in invasion and metastasis of several cancers via extracellular matrix degeneration and assist tumor metastasis to specific sites by chemotaxis. However, the combined effect of uPAR and CXCR4 on small cell lung cancer (SCLC), the most aggressive type of lung cancer, is not clear. In this study, we detected the expression of uPAR and CXCR4 in SCLC tissue samples (n = 50) by immunohistochemistry. The tumors with high expression of both uPAR and CXCR4 (12/50) had larger size, higher lymph node (LN) metastasis and worse prognosis of patients than those with low expression of uPAR and CXCR4 (38/50) (P < 0.05). We further identified and isolated the both uPAR and CXCR4 positive expression subpopulation cells (uPAR⁺CXCR4⁺ cells) from the SCLC cell line H446 by flow cytometry. The uPAR⁺CXCR4⁺ cancer cells showed a higher invasive and migrating capacity in the transwell and wound healing assays compared with other subpopulation cells (P < 0.05). uPAR⁺CXCR4⁺ cells injected subcutaneously in nude mice markedly increased tumor growth and induced lung metastasis, while other subpopulation cells did not. In conclusion, these data suggest that uPAR and CXCR4 co-expression predicts worse prognosis of SCLC patients. uPAR⁺CXCR4⁺ cells promote the tumor growth and play a potential role in metastasis of SCLC.