甲状腺激素促进肿瘤细胞增殖及血管新生信号通路的研究

目的 探讨甲状腺激素促进肿瘤细胞增殖及血管新生的信号通路.方法 体外培养人胶质母细胞瘤细胞系（SNB19）,给予甲状腺激素（主要为T4,100 nmol/L）、四碘甲腺乙酸（tetraiodothyroacetic acid,Tetrac,100 nmol/L）、蛋白激酶C（PKC）抑制剂（2.5 μmol/L）作用后,采用Western印迹方法检测磷酸化蛋白激酶D1（PKD1）、磷酸化组蛋白去乙酰化酶（HDAC）5、磷酸化细胞外信号调节激酶（ERK）1/2的表达,ELISA方法检测细胞培养上清血管内皮生长因子（VEGF）的表达量,3-（4,5）-2-唑噻-（2,5）-二苯基溴化四氮唑蓝（MTT）比色法检测细胞增殖.结果 与对照组相比,T4干预组磷酸化PKD1、磷酸化HDAC5、磷酸化ERK1/2水平均增加（P均＜0.05）,Tetrac干预组及PKC抑制剂干预组磷酸化PKD1、磷酸化HDAC5、磷酸化ERK1/2水平均降低（P均＜0.05）.ELISA结果显示,与对照组相比,T4干预组VEGF浓度升高（56.763±2.611） ng/L vs.（36.597±0.933） ng/L,P＜0.05],Tetrac＋T4干预组VEGF浓度降低（22.215±1.531） ng/L vs.（36.597±0.933） ng/L,P＜0.05].MTT结果显示,与对照组相比,T4干预组OD值较高（0.333±0.020）vs.（0.243±0.006）,P＜0.05],Tetrac干预组OD值较低（0.060±0.016） vs.（0.243±0.006）,P＜0.05].结论 甲状腺激素通过结合整合素αvβ3,激活ERK1/2信号通路促进肿瘤细胞增殖,激活PKC/PKD1/HDAC5信号通路促进血管新生.

Signaling pathway of thyroid hormone on the promotion of tumor cell proliferation and angiogenesis

Objective To study the signaling pathway of proliferation and angiogenesis of tumor cells promoted by thyroid hormone.Methods Human glioblastoma cells（SNB 19） were cultured with thyroid hormone （mainly T4,100 nmol/L）,tetraiodothyroacetic acid （Tetrac,100 nmol/L） or protein kinase C （PKC） inhibitor （2.5 μmol/L）in vitro.The expression of phosphorylated protein kinase D 1 （PKD1）,phosphorylated histone deacetylase （HDAC）5 and phosphorylated extracellular regulated protein kinases （ERK）1/2 were detected by Western blots.The expression of vascular endothelial growth factor （VEGF） in supernatant was measured by ELISA.The proliferation of SNB19 cells was detected by 3-（4,5-Dimethylthiazol-2-yl）-2,5-diphenyltetrazolium bromide（MTT） colorimetric method.Results Compared with control group,phosphorylated PKD1,phosphorylated HDAC5 and phosphorylated ERK1/2 were all increased in T4 group （all P〈0.05）,and decreased in Tetrac＋T4 group and PKC inhibitor group （all P 〈0.05）.The concentration of VEGF in T4 group was enhanced （56.763 ± 2.611） ng/L vs.（36.597 ± 0.933） ng/L,P 〈0.05],while reduced in Tetrac＋T4 group （22.215 ± 1.531） ng/L vs.（36.597 ± 0.933） ng/L,P 〈0.05],compared with control group.The results of MTT showed that compared with control group,the OD value of T4 group was enhanced（0.333 ± 0.020） vs.（0.243 ± 0.006）,P〈0.05],and reduced in Tetrac＋T4 group（0.060 ± 0.016） vs.（0.243 ± 0.006）,P〈0.05].Conclusion Through binding to membrane integrin αvβ3,thyroid hormone promotes the proliferation of tumor cells by activating the ERK1/2 signaling pathway,and promotes angiogenesis by activating the PKC/PKD1/HDAC5 signaling pathway.