肝细胞肝癌(HCC)中PDGF-A的表达及其临床意义

 目的    阐明血小板源性生长因子A(platelet-derived growth factor A,PDGF-A)在人肝细胞肝癌(hepatocellular carcinoma,HCC)组织中的表达情况及临床意义。方法  在手术切除的50例HCC组织中,应用定量RT-PCR的方法检测PDGF-A mRNA水平,并分析其与临床病理分期之间的关系。采用Western blot检测正常肝细胞株L02和7株肝癌细胞株中PDGF-A蛋白质水平。运用免疫组化方法在43例HCC石蜡组织中检测PDGF-A蛋白质水平。再利用免疫荧光双染色方法检测HCC组织中间质区域炎症细胞中PDGF-A与炎症细胞标志物(CD4、CD8、CD19和CD68)共表达情况。结果    与相应癌旁肝组织相比,HCC癌组织PDGF-A mRNA水平升高,约50%(24/50例)癌组织PDGF-A mRNA水平是癌旁肝组织的2倍及以上,这种差异在BCLC 0期和C期的HCC病例中更为显著。PDGF-A蛋白质见于L02、SMMC-7721、HCCLM3和MHCC97-H细胞株,而HepG2、Hep3B、Huh7和BEL-7402细胞株未检测到该蛋白质。近60%的HCC病例中,肝癌细胞表达PDGF-A,阳性染色有两种分布方式:弥漫于胞质内及在细胞质/细胞膜局部聚集。PDGF-A也大量分布于肿瘤间质区域和紧邻癌组织间质区域的炎症细胞(CD4+、CD8+、CD19+和CD68+)中。结论    HCC癌组织PDGF-A基因表达高于癌旁肝组织,在早期和进展期(BCLC 0和C期)病例更为明显;PDGF-A蛋白表达于HCC癌细胞和间质炎症细胞。

The expression of PDGF-A in hepatocellular carcinoma (HCC) and its clinical significance

Objective    To elucidate the expression and significance of platelet-derived growth factor A (PDGF-A) in human hepatocellular carcinoma (HCC) tissues.Methods    Quantitative RT-PCR was used to detect the mRNA level of PDGF-A in tissues resected from 50 patients with HCC,and the relationship between PDGF-A with clinical pathological stage was analyzed.Western Blot was used to detect the protein level of PDGF-A in L02 liver cell line and 7 hepatoma cell lines.Immunohistochemistry was used to detect the distribution of PDGF-A protein in 43 HCC paraffin tissues.The co-expression of PDGF-A and the molecular makers (CD4,CD8,CD19 and CD68) in inflammatory cells were observed by using double immunofluorescence staining technology.Results    Compared with the corresponding adjacent non-tumorous livers,the mRNA level of PDGF-A in HCC tumor tissues was increased,and about 50% (24 of 50 cases) of HCC tumor tissues had over 2 times PDGF-A mRNA level of their adjacent liver tissues.This difference was more significant in the very early stage and advanced stage of HCC (BCLC stage 0 and C).PDGF-A protein was detected in L02,SMMC-7721,HCCLM3 and MHCC97-H cell lines,but not in HepG2,Hep3B,Huh7 and BEL-7402 cell lines.In nearly 60% cases,HCC tumor cells expressed PDGF-A protein,and positive staining had two distribution patterns:diffuse in cytoplasm and local aggregation in cytoplasm/cell membrane.PDGF-A was also abundantly expressed in inflammatory cells (CD4+,CD8+,CD19+ and CD68+) in tumorous and tightly adjacent interstitium.Conclusions    The mRNA level of PDGF-A in HCC tumor tissues was higher than that in adjacent tissues,especially in very early and advanced stages.In HCC tissue,PDGF-A protein was expressed in tumor cells and interstitial inflammatory cells.