功能性CX3CR1基因多态性V249I与肝细胞癌之间无关联。
Lack of association between the functional CX3CR1 polymorphism V249I and hepatocellular carcinoma.
作者信息
Mühlbauer Marcus, Ringel Susanne, Hartmann Arndt, Lallinger Gertrud, Weiss Thomas S, Gäbele Erwin, Wünsch Peter H, Schölmerich Jürgen, Hellerbrand Claus
机构信息
Department of Internal Medicine I, University of Regensburg, D-93042 Regensburg, Germany.
出版信息
Oncol Rep. 2005 May;13(5):957-63.
Chemokine production by cancer cells constitutes a duality. Leukocyte recruitment under the pressure of chemokines may be beneficial for the host or for the tumor. Recently, the chemokine fractalkine and its receptor CX3CR1 have been shown to be expressed in hepatocytes in vivo and in a human hepatocarcinoma cell line in vitro. Therefore, the aim of this study was to analyze the expression of CX3CR1 in hepatocellular carcinoma (HCC) in vivo and to investigate the prevalence of the genetic CX3CR1 polymorphism V249I in HCC patients since this polymorphism has been associated with reduced number of fractalkine binding sites, reduced cell-cell adhesion and decreased signaling and chemotaxis. Genotyping was performed in 183 patients with histologically proven HCC and 99 healthy controls by RFLP-analysis. The frequency of the individual genotypes was similar in HCC patients and controls. The V249I polymorphism revealed no association with tumor grade and stage, the presence of extrahepatic metastasis or the degree of fibrosis in non-tumorous tissue. In addition to genotyping, CX3CR1 mRNA expression was analyzed by quantitative PCR in 9 HCC specimens and in 6 cases in corresponding non-tumorous liver tissues. CX3CR1 mRNA expression levels in HCC showed high variation between individual patients. Similarly, expression in HCC compared to non-tumorous liver varied, from strong downregulation to remarkable upregulation. CX3CR1 mRNA expression levels showed no correlation to the V249I polymorphism. In summary, these results suggest that the patho-physiological role of individual chemokines in carcinogenesis may vary and that the functional CX3CR1 polymorphism V249I is no genetic risk factor for HCC. However, additional independent studies in HCC patients with different ethnic background will be needed to confirm the present study and to elucidate the functional role of CX3CR1 and its polymorphism V249I in chronic liver disease and hepatocarcinogenesis.
癌细胞产生趋化因子具有双重性。在趋化因子作用下募集白细胞可能对宿主或肿瘤有益。最近,已证实在体内肝细胞以及体外人肝癌细胞系中趋化因子fractalkine及其受体CX3CR1均有表达。因此,本研究旨在分析CX3CR1在体内肝细胞癌(HCC)中的表达,并调查HCC患者中CX3CR1基因多态性V249I的流行情况,因为该多态性与fractalkine结合位点数量减少、细胞间黏附降低以及信号传导和趋化性减弱有关。通过限制性片段长度多态性分析(RFLP分析)对183例经组织学证实的HCC患者和99例健康对照进行基因分型。HCC患者和对照中各基因型的频率相似。V249I多态性与肿瘤分级和分期、肝外转移的存在或非肿瘤组织中的纤维化程度均无关联。除基因分型外,通过定量PCR分析了9例HCC标本以及6例相应非肿瘤肝组织中CX3CR1 mRNA的表达。HCC中CX3CR1 mRNA表达水平在个体患者之间差异很大。同样,与非肿瘤肝组织相比,HCC中的表达也有所不同,从强烈下调到显著上调。CX3CR1 mRNA表达水平与V249I多态性无相关性。总之,这些结果表明,个体趋化因子在致癌过程中的病理生理作用可能各不相同,功能性CX3CR1多态性V249I不是HCC的遗传危险因素。然而,需要对不同种族背景的HCC患者进行更多独立研究,以证实本研究结果,并阐明CX3CR1及其多态性V249I在慢性肝病和肝癌发生中的功能作用。