共轭三烯酸对人胶质瘤U251细胞的增殖抑制作用

Inhibitory effects of conjugated trienoic fatty acids on proliferation of human glioblastoma U251 cells in vitro

目的探讨共轭三烯酸（TCLA）对人胶质瘤细胞的增殖抑制作用及作用机制。方法用噻唑蓝（MTr）比色法、克隆形成试验、50溴脱氧尿嘧啶核苷（BrdU）掺人试验研究TCLA对人脑胶质瘤细胞的增殖抑制作用；Hoechst33342／PI双染法、流式细胞术检测细胞凋亡指数和周期分布；逆转录．聚合酶链反应（RT—PCR）检测凋亡相关基因腺苷二磷酸核糖转移酶1（ADPRTL1）、细胞色素P4501A1（CYP1A1），过氧化物酶增殖体激活受体-γ（PPAR-γ）的表达。结果共轭三烯酸对人胶质细胞瘤（U251）有明显抑制作用，呈剂量-时间撤应关系（P〈0．05）。克隆形成下降，40μmol／LTCLA可完全抑制克隆形成。BrdU标记从（91．6±3．6）％下降到（14．4±4．4）％（P〈0．05），Hoechst33342／PI双染试验，凋亡细胞增加（P〈0．05）。流式细胞仪检测显示，细胞凋亡指数从（7．3±1．2）％升高到（34．2±2．4）％（P〈0．05），G。／G。期细胞比例增加，S期细胞比例减少（P〈0．05）；RT—PCR结果显示，凋亡相关基因ADPRTL1、CYP1A1、PPAR-γmRNA表达增强（P〈0．05）。结论TCLA对人脑胶质瘤细胞具有增殖抑制和凋亡诱导作用，其作用机制可能与抑制肿瘤细胞DNA合成、细胞周期阻滞、上调凋亡相关基因（ADPRTL1、CYP1A1、PPAR-γ）表达有关。

Objective To investigate the effect of conjugated trienoic fatty acids （TCLA） on proliferation of human glioblastoma U251 ceils and the action mechanism. Methods Glioblastoma cells were tested in vitro by methyl thiazol tetrazolium （MTT） , colony formation inhibition, BrdU incorporation after treatment with TCLA. The apoptotic cells were assayed through Hoechst 33342/propidium iodide staining and cell cycle analysis by flow cytometry （ FCM）, and the expression of ADPRTL1, CYP1A1 and PPAR-γ genes were detected by using reverse transcription-polymerase chain reaction （RT-PCR）. Results After TCLA treatment, the proliferation of U251 cells was inhibited in a dose- and time-dependent manner （P 〈 0. 05 ）, colony formation decreased significantly （ P 〈 0. 05 ） and BrdU labeling index of cancer cells decreased from （91.6 ± 3. 6） % to （ 14. 4 ± 4. 4） % （ P 〈 0. 05 ） ; apoptotic cells increased ; FCM revealed that the apoptotic indices were increased from （7.3 ±1.2）% to （34. 2 ±2. 4）% （P 〈0. 05）, the cells in G0/G1 phase were increased, and those in S phase decreased （ P 〈 0. 05 ）. RT-RCR showed that TCLA significantly increased the mRNA expression levels of ADPRTL1, CYP1A1, and PPAR-5,. Conclusion The findings in this experimental study suggested that TCLA had potent cytotoxicity and apoptosis induction effect on human glioblastoma U251 cells probably by inhibiting DNA synthesis, blocking cell cycle and upregulating the expression of apoptosis related genes ADPRTL1, CYP1 A1, PPAR-γ.