Zhang Xiaoxiao, Graves Paul, Zeng Yan
Department of Pharmacology, University of Minnesota, Minneapolis, MN 55455, USA.
Biochim Biophys Acta. 2013 Mar;1830(3):2553-61. doi: 10.1016/j.bbagen.2012.11.013.
Argonaute (Ago) proteins are essential for the biogenesis and function of -20-30 nucleotide long RNAs such as microRNAs (miRNAs). Ago expression increases or decreases under various physiological conditions, although the functional consequences are unknown. In addition, while reduced global miRNA production was shown to enhance cellular transformation and tumorigenesis, how Ago proteins contribute to human diseases has not been reported.
Ago2, an essential Ago isoform in mammals, was stably expressed in 293 T, the human embryonic kidney cell line, and H1299, the human lung adenocarcinoma cell line. miRNA and mRNA expression was investigated by quantitative PCR and microarray profiling. Cell proliferation and migration was examined by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay and scratch assay in the cell cultures, respectively. How Ago2 affected cell growth in vivo was determined by H1299 xenograft tumor growth in mice. Changes in Ago2 expression in human lung cancer samples were investigated by quantitative PCR and immunohistochemistry.
Stable Ago2 overexpression elicited specific changes in miRNA and mRNA expression in both 293 T and H1299 cells. It also inhibited cell proliferation and migration in cell cultures as well as xenograft tumor growth in nude mice. Ago2 expression was lower in human lung adenocarcinomas than in the paired, non-cancerous tissues.
We concluded that changes in Ago2 expression might have significant physiological and pathological consequences in vivo.
AGO蛋白对于20 - 30个核苷酸长的RNA（如微小RNA，miRNA）的生物合成和功能至关重要。在各种生理条件下AGO的表达会增加或减少，尽管其功能后果尚不清楚。此外，虽然整体miRNA产生减少已被证明可增强细胞转化和肿瘤发生，但AGO蛋白如何导致人类疾病尚未见报道。
AGO2是哺乳动物中一种重要的AGO异构体，在人胚肾细胞系293 T和人肺腺癌细胞系H1299中稳定表达。通过定量PCR和微阵列分析研究miRNA和mRNA表达。分别通过细胞培养中的3 -（4,5 - 二甲基噻唑 - 2 - 基）- 2,5 - 二苯基四氮唑溴盐试验和划痕试验检测细胞增殖和迁移。通过H1299在小鼠体内异种移植肿瘤生长来确定AGO2如何影响体内细胞生长。通过定量PCR和免疫组织化学研究人肺癌样本中AGO2表达的变化。
AGO2的稳定过表达在293 T和H1299细胞中引发了miRNA和mRNA表达的特异性变化。它还抑制了细胞培养中的细胞增殖和迁移以及裸鼠体内异种移植肿瘤的生长。人肺腺癌中AGO2的表达低于配对的非癌组织。
我们得出结论，AGO2表达的变化可能在体内具有重要的生理和病理后果。
