过氧化物酶体增殖活化受体β／δ表达在非小细胞肺癌中的作用

Function of expression and actions of peroxisome proliferator-activated receptor β/δ in non-small cell lung cancer

目的观察过氧化物酶体增殖活化受体β／δ（PPARβ／δ）表达在非小细胞肺癌中的作用。方法逆转录聚合酶链反应（RT—PCR）、荧光素酶报告基因检测非小细胞肺癌（NSCLC）细胞株及肿瘤组织、正常组组织PPARβ／δ、PPARγ、磷脂酶A2（PLA2）、环氧合酶-2（Cox-2）、前列腺素合酶（PGES）、前列环素合酶（PGIS）的表达水平，基因敲除技术及流式细胞仪分析PPARβ／γ对非小细胞癌细胞增殖与存活的影响，药物综合分析PPARβ／γ对Cox-2与血管内皮生长因子（VEGF）表达的影响。结果H441细胞PPARβ／δ、PPARc、cPLA2、Cox-2、PGES及PPARγ表达水平很高，H358、H23细胞，PPARβ／δ表达水平居中，肿瘤组织PPARβ／δmRNA水平比正常肺组织要高，PPARβ／δ在A549细胞中活性仅为2．3，而在H441细胞中高达6．1，两者差异有统计学意义（P〈0．01），PPARβ／δ具有促进NSCLC细胞增殖与存活的功能，cPGI2（低浓度，能激活PPARβ／δ）能促进细胞增殖、增加细胞稳定性、延长细胞S期、缩短G1期，但对A549细胞几乎没有影响，当cPGI2高达10mg／L时，对H441细胞及H358细胞稳定性有很大的促进作用，稳定性分别高达145和151；siRNA敲除PPARβ／δ影响细胞稳定性，促进细胞凋亡，细胞活力与对照组比较，下降到90％；PPARβ／δ影响Cox-2及VEGF的表达，GW501516（PPARβ／δ的配体）处理NSCLC细胞，Cox-2及VEGFmRNA水平有所上升，但是A549细胞变化不明显。结论PPARβ／δ在NSCLC细胞株及肿瘤组织表达量较高，具有促进NSCLC细胞增殖和稳定性、调节NSCLC细胞周期等功能，并影响Cox-2／VEGF的表达。

Objective To investigate the function of peroxisome proliferator-activated receptor β/δ（PPARβ/δ） expression in non-small cell lung cancer （NSCLC）. Methods Reverse transcription-polymerase chain reaction （RT-PCR） and PPARβ/δ luciferase activity experiment to detect PPARβ/δ, PPARγ, phospholipase A2（PLA2） , cytoehrome C oxidase 2（Cox-2） , prostaglandin E synthase（PGES） , prostacyclin synthase （PGIS） expression level in NSCLC cell lines, NSCLC tissue and normal tissue sample from NSCLC patients. The effect of promoting NSCLC cell lines proliferation and survival mediated by PPARβ/δ was analyzed by siRNA and flow cytometer. The function of PPARβ/δ in regulating the express of Cox-2 and vascular endothelial growth factor （VEGF） gene was confirmed by medicine experiment. Resuits H441 cells had high levels of PPARβ/δ, Cox-2, cPLA2, PGES and PPARc. H358 and H23 cells had intermediate levels of PPARβ/δ. The PPARβ/δ mRNA level was higher in tumor tissues compared to normal tissues. PPARβ/δ had the function of increasing NSCLC proliferation and survival and low level cPGI2 （activate the PPARβ/δ） could improving NSCLC proliferation and viability, prolonging the S cell cycle and shortening the G1 cell cycle. But there nearly was no impact in A549 ceils. Decreasing the cell proliferation and viability and promoting apoptosis when knock-down the PPARβ/δ by siRNA and regulating the Cox-2 and vascular endothelial growth factor （VEGF） expression by PPARβ/δ. There was increasing of Cox-2 and VEGF mRNA during the GW501516 （the ligand of PPARβ/δ） treating NSCLC. But, no change was detected in A549 cells. Conclusion Up-expression in NSCLC compared to normal tissues. There are many function of PPARβ/δ in NSCLC including promoting NSCLC proliferation, survival and viability and affecting the Cox-2, VEGF expression. Together, these data suggest that PPARβ/δ might local the central of multiple signaling pathways and control the NSCLC proliferation.