血小板因子4基因转染对肺癌细胞中血管生成因子基因表达的影响

摘要

目的：进一步探讨人血小板因子4(hPF4)抑制血管生成的作用机制。方法：构建含全长hPF4 cDNA重组真核表达载体pcDNA3-hPF4，将其转染到人肺巨细胞癌细胞系PLA801D细胞内，应用RT-PCR及免疫组化法观察肿瘤细胞自分泌的血管内皮生长因子(VＥGF)、碱性成纤维细胞生长因子(bFGF)、白细胞介素8(IL-8)等的mRNA和蛋白表达水平的变化。结果：导人pcDNA3-hPF4,PLA801D细胞能稳定表达hPF4 mRNA，其VEGF、bFGF、IL-8的mRNA和蛋白表达水平均明显降低，表明hPF4可直接调控VEGF、bFGF、IL-8等基因转录，影响其蛋白质生物合成。结论：提示hPF4可直接下调肿瘤细胞自分泌的VEGF、bFGF及IL-8等血管生成因子基因转录，抑制肿瘤细胞释放肿瘤血管生成因子，是hPF4抗血管生成抑制肿瘤细胞生长的机制之一。%Objective: To study the inhibiting angiogenesis mechanism of human platelet factor 4(hPF4).Methods:A hPF4 gene recombinant expression vector was constructed by cloning hPF4 cDNA into the pcDNA3 vector, and was transferred by lipofectamin into hPF4 deficient human pulmonary giant cell carcinoma ecll line (PLA801D) with lipofectamin. The mRNA and protein expression level of PLA801D-hPF4 cell was detected by RT-PCR and immunocytochemistry. Results:Stable expression of hPF4 mRNA in PLA801D-hPF4 cells was confirmed by RT PCR. The angiogenic factor VEGF、bFGF、IL-8 mRNA and protein expression of PLA801D-hPF4 cell was significantly inhibited compared with the controls. These results demonstrate that transfection of hPF4 gene into lung cancer cells could reduce its angiogenic factors mRNA expression, so it also effects the compositinn of their protein. Conclusion:These date indicated that down-regulated mRNA expression of the angiogenic factor in cancer eclls can be one of the mecharnisms of inhibiting angiogenesis of hPF4.