CpG-ODN对肺腺癌细胞增殖的抑制作用及其与Runx3关系的初步研究

目的探讨CpG-ODN对人肺腺癌A549细胞的增殖及其抑癌基因Runx相关转录因子3(Runx3)表达的影响,探讨TLR9与肺腺癌发生发展的关系,为基于TLR9的肿瘤治疗寻找理论依据。方法不同浓度CpG-ODN作用于人肺腺癌A549细胞系,用RT-PCR和Western blot分别检测Runx3在mRNA和蛋白水平的表达情况。针对Runx3基因的特定靶位,采用化学合成法合成Runx3 siRNA,并瞬时转染A549细胞,用MTT法检测CpG-ODN对转染前后的细胞生长作用的影响。结果 CpG-ODN能明显抑制A549细胞的增殖;不同浓度CpG-ODN刺激A549后,细胞中Runx3基因在mRNA和蛋白表达水平均增加;Runx3 siRNA的瞬时转入对CpG-ODN刺激的A549增殖抑制作用明显减弱。结论 TLR9的配体CpG-ODN可抑制A549细胞的增殖,同时正向调控Runx3的表达。由此推测,CpG-ODN可能通过上调Runx3抑制A549细胞的增殖。     

Transactivation by Runt related factor-2 of matrix metalloproteinase-13 in astrocytes

We have previously shown functional expression by osteoblasts of signaling machineries required for neurotransmission in the brain. In this study, we have evaluated possible functional expression of different osseous genes in the brain. In embryonic and adult mouse brains, mRNA expression was invariably seen for the master regulator of osteoblastic differentiation Runt related factor-2 (Runx2), in addition to the partner protein core binding factor-β and their targets such as osteopontin (OPN) and matrix metalloproteinase-13 (MMP13), but not for collagen-I or osteocalcin. In pluripotent P19 progenitor cells, Runx2 mRNA expression was drastically increased along with mRNA expression of an astrocytic marker, but not with neuronal marker mRNA expression. Both mRNA and corresponding protein were detected for Runx2 in cultured rat neocortical astrocytes and astrocytic C6 glioma cells. In C6 glioma cells, transient overexpression of Runx2 significantly increased mRNA expression of MMP13, but not of OPN. Moreover, transient overexpression of Runx2 significantly increased luciferase activity in C6 glioma cells transfected with the reporter plasmid linked to a wild-type Runx2 binding element in the MMP13 promoter, but not in cells with a mutated element. These results suggest that Runx2 signal input may lead to transactivation of MMP13 gene without affecting OPN expression in astrocytes.