5－氮杂胞苷和白桦脂酸诱导膀胱癌细胞T24中内皮生长因子异构体差异性表达

Differential expression of splice variants of VEGF in the bladder cancer cell T24 treated with 5-azacytidine or betulinic acid

目的:观察5-氮杂胞苷及转录因子Sp1(special Protein 1)抑制剂白桦脂酸(betulinic acid)对T24人膀胱癌细胞株血管内皮生长因子(vascular erndothelial growth factor,VEGF)及其异构体表达的影响,揭示VEGF基因异构体表达的变化规律。方法:分别以不同浓度的5-氮杂胞苷、白桦脂酸作用于T24细胞,RT-PCR检测细胞内总VEGF、刺激性异构体VEGF_(165)和VEGF_(121)、抑制性异构体VEGF_(165)b的mRNA表达变化;构建VEGF_(165)b表达质粒稳定转染T24细胞,RT-PCR检测外源性VEGF_(165)b对VEGF_(165)表达的影响。结果:5-氮杂胞苷作用T24细胞后,细胞总VEGF mRNA及其刺激性异构体VEGF_(165)和VEGF_(121),表达明显增加,而抑制性异构体VEGF_(165)b表达减少;以白桦脂酸作用T24细胞后,细胞内总VEGF及刺激性异构体表达减少,但抑制性异构体VEGF_(165)b表达增加;而稳定转染VEGF_(165)b表达质粒的T24细胞,VEGF_(165)表达减少。结论:人膀胱癌细胞株T24受干预后,VEGF及其异构体基因的变化有一定规律。当细胞内总VEGF表达增加时,刺激性异构体表达增加而抑制性异构体表达减少;而总VEGF表达减少时,刺激性异构体表达减少而抑制性异构体表达增加。此外,VEGF_(165)b可拮抗VEGF_(165)的表达。

OBJECTIVE To determine the differential expression of total VEGF, pro-angiogenesis and anti-angiogenesis isoforms of VEGF in human carcinoma of bladder cell T24 when treated with 5-azacytidine or betulinic acid respectively. METIt- ODS The mRNA expression of total VEGF, pro-angiogenesis and anti-angiogenesis isoforms was detected by RT-PCR after treatment with 5-azacytidine or betulinic acid. RESULTS After treatment with 5-azacytidine, there was an increase in the expression of total VEGF and pro-angiogenesis isoforrns of VEGF, while the expression of anti-angiogenesis isoforms was decreased. When treated with betulinic acid, the expression of total VEGF and pro-angiogenesis isoforms was decreased, while the expression of anti-angiogenesis isoforms was increased. Moreover, the mRNA expression of VEGF16s b decreased when T24 cells were transfected with pVEGF16s b. CONCLUSION A differential expression of total VEGF, pro-angiogenesis and anti-angiogenesis isoforms of VEGF was observed in human bladder cancer cell when it was subjected to some specific treatments. When the expression of total VEGF wass up-regulated, the expression of pro-angiogenesis isoforms was increased and that of anti-angiogenesis isoforms was decreased. However, when the expression of total VEGF was down-regulated, the expression of pro-angiogenesis isoforms wass decreased while that of anti-angiogenesis isoforms was increased. Furthermore, VEGF165 b had an antagonistic effect on the expression of VEGF165.