趋化因子受体及配体在卵巢癌细胞迁移中的作用

背景与目的:研究表明许多肿瘤细胞表达趋化因子受体,与肿瘤细胞的迁移与转移有密切关系。本研究拟探讨趋化因子受体CXCR4[chemokine(C.X.C)receptor4]及配体CXCL12[chemokine(C.X.Cmotif)ligand12]在上皮性卵巢癌细胞中的表达及在肿瘤细胞迁移中的作用。方法:采用RT鄄PCR和Westernblot检测15例上皮性卵巢癌组织、卵巢癌细胞株CAOV3、血管内皮细胞株HUVEC和10例正常卵巢组织中CXCR4的表达以及卵巢癌患者腹膜后淋巴结组织和输卵管平滑肌组织中CXCL12的表达。ELISA检测15例上皮性卵巢癌患者腹水中趋化因子CXCL12的含量。以Boyden小室检测重组人CXCL12、上皮性卵巢癌癌性腹水对CAOV3和HUVEC细胞的趋化活性的影响。结果:(1)在上皮性卵巢癌组织、CAOV3及HUVEC细胞中,CXCR4在mRNA及蛋白水平的相对表达量分别为2.30±1.12、1.89±1.20、1.68±1.11及1.35±0.14、1.86±0.34、1.96±0.23,正常卵巢组织在mRNA及蛋白水平均未检测到CXCR4表达;(2)卵巢癌癌性腹水定量检查结果显示,CXCL12含量为632～9326pg/ml(中位数为6237pg/ml)。卵巢癌患者腹膜后淋巴结组织中,CXCL12mRNA表达量的平均值为1.14±0.87,卵巢癌患者输卵管平滑肌组织未检测出CXCL12表达;(3)重组人CXCL12可诱导CAOV3及HUVEC细胞的迁移,其趋化指数分别为3.     

CO2气腹对人卵巢癌SKOV3细胞裸鼠移植瘤CXCL12、CXCR4表达的影响

  目的  探讨二氧化碳（CO₂）气腹在相同压力不同时间对卵巢癌裸鼠移植瘤CXCL12、CXCR4表达的影响。  方法  建立40只人卵巢癌SKOV3细胞裸鼠移植瘤动物模型,随机分为4组,每组10只,分别为单纯麻醉组、开腹组、CO₂气腹0.5 h组、CO₂气腹1 h组,成瘤后按以上分组处理后,取出肿瘤组织并采用PCR法检测各组中CXCL12,CXCR4 mRNA的表达,Western blot法检测CXCL12,CXCR4蛋白表达。  结果  40只人卵巢癌SKOV3细胞裸鼠移植瘤动物模型建立成功,经实验处理后RT-PCR提示CO₂气腹1 h组瘤体CXCL12 mRNA表达显著高于其余3组,而CXCR4 mRNA无表达差异,Western blot也提示CO₂气腹1 h组瘤体CXCL12蛋白表达显著高于其余3组,而CXCR4蛋白无表达差异。  结论  CO₂气腹1 h组可提高卵巢癌SKOV3细胞CXCL12的表达水平,可能对腹腔移植瘤生长具有促进作用,而对转移影响意义不大。      

趋化因子受体CXCR4/CXCL12信号转导通路与胃癌淋巴结转移关系的研究

目的：检测趋化因子受体CXCR4/CXCL12信号转导通路在胃癌组织、远癌正常粘膜以及转移淋巴结中的表达情况,分析CXCR4/CXCL12在胃癌淋巴结转移中的作用。方法：应用Westernblot检测胃癌组织中CXCR4/CXCL12通路成员表达。结果：胃癌组织中CXCR4/CXCL12表达水平明显高于正常胃粘膜（P〈0.05）;32例淋巴结转移癌组织中22例CXCR4/CXCL12蛋白表达高于原发癌;CXCR4/CXCL12表达水平与淋巴结转移有关（P（0.05）。结论：趋化因子受体CXCR4/CXCL12在原发胃癌及其淋巴结转移癌组织中均呈高表达,CXCR4信号转导通路可能在胃癌淋巴结转移过程中起重要作用。     

趋化因子受体CXCR4及其配体CXCL12在胃癌组织中的表达及其意义

目的 探讨CXCR4/CXCL12在胃癌组织中表达及其在肝转移中的作用。方法 应用Western blot 检测40例胃癌患者标本中肿瘤组织、邻近正常黏膜以及肝转移组织中CXCR4/CXCL12通路成员的表达情况,免疫组织化学法检测CXCR4/CXCL12在细胞水平的分布。结果 胃癌组织中CXCR4/CXCL12表达水平明显增高（肿瘤组织vs正常黏膜,P<0.05）;10例肝转移组织中CXCR4/CXCL12表达增高（转移组织vs原发肿瘤,P<0.05）;CXCR4/CXCL12表达水平与TNM 分期晚（Ⅲ/Ⅳ）有关（P<0.05）。结论 CXCR4/CXCL12信号转导通路可能在胃癌肝转移过程中起一定作用,详细机制尚待进一步研究。     

CXCR4和CXCR7在肿瘤中的研究进展

以往的研究认为趋化因子受体4(chemokine receptor 4,CXCR4)是趋化因子CXCL12的唯一受体,CXCL12/CXCR4生物轴在肿瘤发展过程中起重要作用,然而最近研究发现CXCL12尚存在CXCR7这一新的受体,并且CXCL12/CXCR7生物轴同样对肿瘤的发生发展起重要作用.本文就有关趋化因子受体CXCR4和CXCR7在肿瘤中的表达、促进肿瘤增殖和转移、促进血管新生以及肿瘤治疗等方面的研究作一综述.     

胰腺癌CXCL12/CXCR4通路研究进展

目的:总结CXCL12/CXCR4生物学轴与胰腺癌侵袭和转移关系的研究现状.方法:应用PubMed及CNKI期刊全文数据库检索系统,以“CXCL12、CXCR4和胰腺癌”等为关键词,检索2005-2011年的相关文献,共检索到中文文献56条,英文文献152条.纳入标准:1)CXCL12-CXCR4生物学轴的生物学特性及功能;2)CXCL12/CXCR4生物学轴与肿瘤发生、发展的关系;3)CXCL12/CXCR4生物学轴信号转导通路的相关调控因子及其调节机制;4)CXCL12/CXCR4生物学轴在胰腺癌侵袭、转移中的作用及其机制;5)CXCL12/CXCR4生物学轴与胰腺癌的治疗及预后.根据纳入标准共采用中文文献3条,英文文献17条.结果:趋化因子受体CXCR4与其配体CXCL12结合组成的生物学轴具有高度特异性,在胰腺癌细胞的黏附、侵袭、转移、增殖和生存中发挥重要作用,与细胞外基质降解、胰腺癌血管、淋巴管生成及嗜神经侵袭密切相关,并受相关因子调控影响其信号转导通路.结论:CXCL12/CXCR4生物学轴在胰腺癌发生、发展中发挥着重要作用,有望成为胰腺癌靶向治疗的新靶点,但其具体作用的相关转导通路和调节机制还未完全明确,有待进一步研究.     

趋化因子受体CXCR7及其与肿瘤的关系

CXCR7是继CXCR4之后发现的趋化因子CXCL12的新受体.目前研究表明,CXCL12/CXCR7生物轴对多种肿瘤的发展有重要影响,与CXCL12/CXCR4生物轴的作用有一定相似性.CXCR7广泛表达于多种肿瘤组织及肿瘤细胞,在肿瘤细胞的生长增殖、黏附迁徙中起重要作用.抑制CXCR7表达或阻断其信号传导通路可能为肿瘤治疗提供新策略.     

趋化因子CXCL12与肿瘤

趋化因子CXCL12又称基质细胞衍生因子-1,是一个定位于10号染色体由基质细胞产生的CXC类趋化因子.目前认为CXCR4和CXCR7是CXCL12的两个受体.多项研究发现CXCL12在肿瘤细胞增殖、转移及血管生成过程中发挥重要作用.因此,CXCL12有望成为肿瘤基因治疗的新靶点.     

CXCL12，CXCR4及CXCR7表达检测对乳腺癌患者疾病预后意义探讨

目的：探讨乳腺癌患者肿瘤组织中CXCL12,CXCR4和CXCR7 mRNA表达情况在肿瘤转移和疾病预后中的价值。方法采用定量PCR方法检测115例乳腺癌,临近正常组织及乳腺癌肿瘤转移患者颈部淋巴结样本中CXCL12,CXCR4和CXCR7 mRNA表达情况。随访资料采用Kaplan-Meier生存分析,对影响生存质量的因素进行多重变量Cox回归分析。结果与正常组织相比,乳腺癌组织中CXCR4和CXCR7表达明显增加,差异均有统计学意义（P﹤0.001）,两种组织中CXCL12的表达差异无统计学意义（P﹥0.05）;CXCL12在肿瘤原发部位和淋巴结转移部位的表达差异有统计学意义（P﹤0.05）,转移瘤的CXCR4和CXCR7表达均增加（P﹤0.05）。Kaplan-Meier生存分析结果表明,与CXCR4和CXCR7低表达患者相比,高表达患者的总生存率较低（P﹤0.05）。Cox回归模型显示,CXCL12、CXCR4和CXCR7表达均为影响乳腺癌患者生存情况的独立因素。结论本研究结果表明CXCL12、CXCR4和CXCR7 mRNA表达在乳腺癌患者肿瘤发展和转移中发挥重要作用,可以作为乳腺癌患者疾病预后的生物标志物。     

CXCL12和CXCR4在食管鳞癌组织中的表达及其与预后的关系

背景与目的：新近研究显示CXCL12／CXCR4在多种肿瘤组织中有表达,并与肿瘤细胞的增殖、侵袭特性相关;本研究旨在检测CXCL12及其受体CXCR4在食管鳞癌中的表达,研究两者对食管癌预后的影响及其与临床及病理因素之间的关系。方法：收集食管癌术后标本186例及正常食管上皮组织20例（对照组）,应用免疫组化法检测食管癌组织中CXCR4与CXCL12的表达。结果：186例食管癌组织中CXCR4的表达率为67．2％,CXCL12的表达率为63．4％,20例正常食管上皮组织中无CXCR4及CXC112蛋白表达。多因素分析：PTNM分期及CXCR4的表达是影响食管癌根治术后患者预后的独立因素（P〈0．05）：CXCL12阳性组与阴性组5年生存率分别为18．8％和21．0％,差异无统计学意义（P〉0．05）。CXCR4阳性组与阴性组5年生存率分别为2．2％和28．5％。差异有统计学意义（P〈0．05）;有淋巴结转移组及病理分期T3期组CXCR4表达率较无淋巴结转移组及病理分期T1-2组高（P〈0．05）,食管癌组织中CXCR4的表达与CXCL12的表达之间无相关性。结论：CXCL12和CXCR4在食管癌组织中均有较高的表达,CXCR4的表达水平与食管肿瘤的发展及预后有一定的关系。     

PGE(2)-induced CXCL12 production and CXCR4 expression controls the accumulation of human MDSCs in ovarian cancer environment

Signals mediated by CXCL12 (SDF1) and its receptor CXCR4 are centrally involved in cancer progression, both directly by activating cancer cells and indirectly by inducing angiogenesis plus recruiting T regulatory and plasmacytoid dendritic immune cells. Here, we show that in ascites isolated from ovarian cancer patients, both CXCL12 and CXCR4 are controlled by the tumor-associated inflammatory mediator prostaglandin E(2) (PGE(2)), which attracts myeloid-derived suppressor cells (MDSC) into the ascites microenvironment. In this setting, PGE(2) was essential both for expression of functional CXCR4 in cancer-associated MDSCs and for production of its ligand CXCL12. Frequencies of CD11b(+)CD14(+)CD33(+)CXCR4(+) MDSCs closely correlated with CXCL12 and PGE(2) levels in patient ascites. MDSCs migrated toward ovarian cancer ascites in a CXCR4-dependent manner that required COX2 activity and autocrine PGE(2) production. Inhibition of COX2 or the PGE(2) receptors EP2/EP4 in MDSCs suppressed expression of CXCR4 and MDSC responsiveness to CXCL12 or ovarian cancer ascites. Similarly, COX2 inhibition also blocked CXCL12 production in the ovarian cancer environment and its ability to attract MDSCs. Together, our findings elucidate a central role for PGE(2) in MDSC accumulation triggered by the CXCL12-CXCR4 pathway, providing a powerful rationale to target PGE(2) signaling in ovarian cancer therapy.     

CXCL12及受体CXCR4在卵巢上皮性癌中的表达及其临床意义

目的:探讨趋化因子CXCL12及其受体CXCR4在卵巢上皮性癌组织中的表达及与临床病理特征和预后的关系。方法:采用免疫组织化学SP法检测6例正常卵巢表面上皮、44例卵巢上皮性癌原发灶和30例相应大网膜转移灶组织中的CXCL12和CXCR4蛋白表达。结果:正常卵巢表面上皮无CXCL12和CXCR4蛋白表达;卵巢上皮性癌原发灶的CXCL12和CXCR4表达阳性率分别为91%和59%。CXCL12表达强度与术中腹水量有显著相关性(P=0.014)。难治复发组的CXCR4阳性率(81%)显著高于无复发组(28%,P<0.001)。单因素分析显示:CXCR4阳性表达的患者中位数肿瘤无进展生存时间和总生存时间(15个月、27个月)明显短于CXCR4阴性表达者(>21个月、>32个月,分别为P<0.001和P=0.017)。多因素分析显示:CXCR4表达和残余灶大小是影响卵巢上皮性癌患者的肿瘤无进展生存时间和总生存时间的独立预后因素。结论:CXCR4在卵巢上皮性癌中的表达阳性率较高,是影响其预后的独立指标之一。     

CXCL12/CXCR4 blockade induces multimodal antitumor effects that prolong survival in an immunocompetent mouse model of ovarian cancer

The chemokine CXCL12 and its receptor CXCR4 are expressed widely in human cancers, including ovarian cancer, in which they are associated with disease progression at the levels of tumor cell proliferation, invasion, and angiogenesis. Here, we used an immunocompetent mouse model of intraperitoneal papillary epithelial ovarian cancer to show that modulation of the CXCL12/CXCR4 axis in ovarian cancer has multimodal effects on tumor pathogenesis associated with induction of antitumor immunity. siRNA-mediated knockdown of CXCL12 in BR5-1 cells that constitutively express CXCL12 and CXCR4 reduced cell proliferation in vitro, and tumor growth in vivo. Similarly, treatment of BR5-1-derived tumors with AMD3100, a selective CXCR4 antagonist, resulted in increased tumor apoptosis and necrosis, reduction in intraperitoneal dissemination, and selective reduction of intratumoral FoxP3(+) regulatory T cells (Treg). Compared with controls, CXCR4 blockade greatly increased T-cell-mediated antitumor immune responses, conferring a significant survival advantage to AMD3100-treated mice. In addition, the selective effect of CXCR4 antagonism on intratumoral Tregs was associated with both higher CXCR4 expression and increased chemotactic responses to CXCL12, a finding that was also confirmed in a melanoma model. Together, our findings reinforce the concept of a critical role for the CXCL12/CXCR4 axis in ovarian cancer pathogenesis, and they offer a definitive preclinical validation of CXCR4 as a therapeutic target in this disease.     

Noninvasive Imaging Reveals Inhibition of Ovarian Cancer by Targeting CXCL12-CXCR4

Patients with metastatic ovarian cancer continue to have a dismal prognosis, emphasizing the need for new strategies to identify and develop new molecular targets for therapy. Chemokine CXCL12 and its receptor CXCR4 are upregulated in metastatic ovarian cancer cells and the intraperitoneal tumor microenvironment. CXCL12-CXCR4 signaling promotes multiple steps in proliferation and dissemination of ovarian cancer cells, suggesting that targeted inhibition of this pathway will limit tumor progression. To investigate CXCL12-CXCR4 signaling in ovarian cancer and establish effects of inhibiting this pathway on tumor progression and survival, we designed a Gaussia luciferase complementation imaging reporter system to detect CXCL12 binding to CXCR4 in ovarian cancer cells. In cell-based assays, we established that the complementation imaging reporter could detect CXCL12 binding to CXCR4 and quantify specific inhibition of ligand-receptor interaction. We monitored CXCL12-CXCR4 binding and inhibition in a mouse xenograft model of metastatic human ovarian cancer by imaging Gaussia luciferase complementation and assessed tumor progression with firefly luciferase. Bioluminescence imaging studies in living mice showed that treatment with AMD3100, a clinically approved inhibitor of CXCL12-CXCR4, blocked ligand-receptor binding and reduced growth of ovarian cancer cells. Treatment with AMD3100 also modestly improved overall survival of mice with metastatic ovarian cancer. The Gaussia luciferase complementation imaging reporter system will facilitate further preclinical development and optimization of CXCL12-CXCR4 targeted compounds for treatment of ovarian cancer. Our research supports clinical translation of existing CXCR4 inhibitors for molecular therapy for ovarian cancer.     

Multiple actions of the chemokine CXCL12 on epithelial tumor cells in human ovarian cancer

Of 14 chemokine receptors investigated, only CXCR4 was expressed on ovarian cancer cells [C. J. Scotton et al., Cancer Res., 61: 4961-4965, 2001]. To further understand the role of this chemokine receptor in ovarian tumor biology, we studied the action of its ligand, CXCL12 (stromal cell-derived factor 1), on the CXCR4-expressing ovarian cancer cell lines IGROV. Ligand stimulation of the CXCR4 receptor resulted in sustained activation of Akt/protein kinase B and biphasic phosphorylation of p44/42 mitogen-activated protein kinase in IGROV. When IGROV cells were cultured under suboptimal conditions, CXCL12 stimulated their in vitro growth, an effect that was abrogated by neutralizing antibodies to CXCR4. This increase in cell number was attributable to stimulation of DNA synthesis, not protection from apoptosis. CXCL12 treatment of IGROV cells also induced mRNA and protein for tumor necrosis factor alpha, a cytokine that is expressed by tumor cells in ovarian cancer biopsies. IGROV cells invaded through Matrigel toward a CXCL12 gradient. Invasion was abrogated by the broad spectrum matrix metalloproteinase and TNFalpha converting enzyme inhibitor Marimastat and was partially inhibited by neutralizing antitumor necrosis factor alpha antibodies. These effects were not limited to the IGROV cell line. They could also be demonstrated in the CAOV-3 ovarian cancer cell line and primary ovarian tumor cells isolated from ovarian ascites. These biological effects of CXCL12 on IGROV cells were also inhibited by the small molecular weight CXCR4 antagonist AMD3100. Finally, we found abundant intracellular CXCL12 protein in tumor cells in 15 of 18 ovarian cancer biopsies but not in epithelial cells from normal ovary or borderline disease. The chemokine CXCL12 may have multiple biological effects in ovarian cancer, stimulating cell migration and invasion through extracellular matrix, as well as DNA synthesis and establishment of a cytokine network in situations that are suboptimal for tumor cell growth.     

CXCL12- CXCR4在乳腺浸润性导管癌中的表达及临床意义

目的：研究乳腺浸润性导管癌中趋化因子 CXCL12及其对应的特异趋化因子受体 CXCR4的表达,分析其与浸润性导管癌临床病理学特征的关系。方法：用免疫组化法研究200例乳腺浸润性导管癌中 CX-CL12、CXCR4的表达情况,并探讨二者单一表达或共表达与临床病理因素的相关性。结果：CXCL12在40%（80/200）浸润性乳腺癌中阳性表达,其与 TNM 分期和肿瘤大小相关（P <0.05）;CXCR4在48%（96/200）浸润性乳腺癌中阳性表达,其表达与浸润性乳腺癌的 TNM 分期相关（P <0.05）。CXCL12与 CXCR4共表达于29%（58/200）的浸润性乳腺癌,二者的共表达与 TNM 分期和淋巴结转移情况相关（ P <0.01）。结论：CX-CL12与 CXCR4共表达很可能是协同乳腺浸润性导管癌进展及淋巴结转移的重要因素,检测 CXCL12与 CX-CR4共表达比检测 CXCL12或 CXCR4单一分子标记更有意义。     

Epithelial cancer cell migration: a role for chemokine receptors?

We investigated the possibility that chemokine gradients influence migration of human ovarian epithelial tumor cells. Of 14 chemokine receptors investigated, only CXCR4 was expressed on ovarian cancer cells. CXCR4 mRNA localized to a subpopulation of tumor cells in ovarian cancer biopsies. Ovarian cancer cell lines and cells freshly isolated from ascites expressed CXCR4 protein. The CXCR4 ligand, CXCL12, was found in ascites from 63 patients. CXCL12 elicited intracellular calcium flux and directed migration and changes in integrin expression in ovarian cancer cells. CXCR4 may influence cell migration in the peritoneum, a major route for ovarian cancer spread, and could be a therapeutic target.