Background and objective: Curcumin, a natural compound, is derived from the rthizom of Curcuma longa. In vitro and in vivo preclinical studies have shown its anti-inflammatory, antioxidant, anticancer activities and so on. miR-186*, which was found by microarray technology, was highly expressed in lung carcinoma cells A549/DDP. The aim of this study is to illustrate whether Curcumin could promote the apoptosis of A549/DDP cells through regulating the expression of miR-186*.
Methods: An oligonucleotide microarray chip was used to profile microRNA (miRNA) expressions in A549/DDP cells treated with and without Curcumin. The significantly differentially expressed miRNA, which was selected from microarray chip, validated by quantitative real-time PCR. Ultimately, the remarkably expressed miRNA modulated the apoptosis assaying by flow cytometry expriments and the survival rate was measured by MTT method.
Results: The microarray chip results demonstrated: Curcumin altered the expression level of miRNAs compared with untreated control in A549/DDP cell line, miR-186* was significantly down-regulated after Curcumin treatment, which confirmed by quantitative real-time PCR. Down-regulation of miR-186* expression by curcumin elevated the apoptosis, and the survival rate of A549/DDP cells decreased; but up-regulation of miR-186* expression by transfection its mimics restrained the apoptosis, the survival rate of A549/DDP cells increased, which were assayed by flow cytometry expriments and MTT method.
Conclusion: Modulation of miRNAs expression may be an important mechanism underlying the biological roles of Curcumin.
背景与目的: 姜黄素是从姜黄科植物的根茎中提取的一种天然化合物。体内外的临床前研究表明，其具有抗炎、抗氧化、抗肿瘤等多种作用。miR-186*是通过microarray芯片技术发现的在人肺腺癌细胞A549/DDP细胞中高表达的基因。本研究旨在阐明姜黄素是否可通过调控miR-186*的表达而促进A549/DDP细胞的凋亡。
方法: microarray芯片技术检测经姜黄素、DMSO分别处理后A549/DDP细胞中microRNAs（miRNAs）表达量的变化；实时定量PCR验证从microarray芯片中筛选出来的明显差异表达的miRNAs；最后，流式细胞仪法检测明显差异表达的miRNAs调控的细胞凋亡，MTT法检测细胞存活率。
结果: microarray芯片技术结果显示：与DMSO对照组比较，姜黄素处理后miR-186*的表达明显下调。实时定量PCR验证了microarray芯片技术检测的结果。流式细胞仪法检测miR-186*调控的细胞凋亡，MTT法检测细胞存活率：姜黄素处理后，与对照组比较，miR-186*的表达明显下调，从而加速A549/DDP细胞的凋亡，细胞存活率下降；转染miR-186*的mimetics和其对照后，与对照组比较，miR-186*的表达上调，从而减少A549/DDP细胞的凋亡，细胞存活率增加。
结论: 姜黄素调控miRNAs的表达可能是其促肺癌细胞凋亡的重要机制之一。