SIRT1通过调节Noxa表达影响非小细胞肺癌细胞株A549对顺铂的敏感性

SIRT1 Influences the Sensitivity of A549 Non-small Cell Lung Cancer Cell Line to Cisplatin via Modulating the Noxa Expression

背景与目的非小细胞肺癌的顺铂耐药是常见的临床现象,严重制约了患者的化疗效果,是亟待解决的问题。SIRT1和Noxa的表达变化影响肿瘤细胞对化疗药物的敏感性。本研究旨在研究SIRT1表达对非小细胞肺癌对顺铂的敏感性的影响,并探讨其涉及Noxa表达的机制,以求为提高非小细胞肺癌细胞对顺铂敏感性提供希望。方法利用实时荧光定量PCR和Western blot分析A549细胞及顺铂耐药的A549/DDP细胞SIRT1及Noxa m RNA和蛋白水平的表达差异。利用si RNA干扰技术抑制A549/DDP细胞的SIRT1表达,进而使用Cell Titer Blue试验、流式细胞术从细胞增殖、细胞周期和细胞凋亡方面分析SIRT1沉默对A549/DPP细胞顺铂敏感性的影响。同时利用实时荧光定量PCR和Western blot分析SIRT1抑制对A549/DPP细胞Noxa表达的影响。结果 A549细胞和A549/DDP细胞对顺铂的敏感性有显著差异,与A549细胞相比,A549/DDP细胞的SIRT1表达较高,但Noxa表达较低。使用si RNA抑制A549/DPP细胞的SIRT1表达后,与未抑制SIRT1细胞相比,4μg/m L顺铂处理后的细胞存活率降低,G2期/M期阻滞比例增加,凋亡率提高。同时,SIRT1沉默导致A549/DPP细胞的Noxa表达增加。结论较高的SIRT1可能引起A549细胞对顺铂的耐药性,抑制SIRT1可以提高A549/DDP细胞对顺铂的敏感性,其机制可能涉及SIRT1对Noxa的调节。

Background and objective The resistance of non-small cell lung cancer cells to cisplant is a common clinical phenomenon which could induce a poor therapeutic effect and should be difficult problem to be solved. SIRT1 and Noxa expression are associated with the chemotherapy for tumors, The present study focused on how SIRT1 expression influ- ence the senstivity of non-small cell lung cancer cells and dissected the potential mechanism involved with Noxa. Methods The difference of SIRT1 and Noxa expression between A,549 cells and A549/DDP cells was detected by real-time quantitative PCR （qRT-PCR） and Western blot. SIRT1 targeted siRNA was uesed to inhibit the SIRT1 expression in A,S49/DDP, after transfection, Cell Titer Blue assay, flow cytometry were performed to analyze the cell viability, cell cycle and cell apoptosis in order to reveal the effect of inhibition of SIRT 1 on sensitivity of A549/DDP cells to cisplant. Moreover, the expression changes of Noxa in A549/DDP cells after siRNA treatment were detected by qRT-PCR and Western blot. Results There was a signifi- cant difference in senstivity to cisplant between A549 and AS49/DDP cells. Compared with A549 cells, the A549/DDP cells showed a higher SIRT1 expression and lower Noxa expression. After transfected with SIRT1 targeted siRNA, the cell viability decreased accompanied with a increasing apoptosis rate, meanwhile, higher percent of G2/M phase was detected after the 4 μg/mL cisplant treatment. Further more, inhibition of SIRT1 could induce the Noxa expression in A549/DDP cells. Conclu- sion Higher SIRT1 expression may induce resistance to cisplant in A549 cells. SIRT1 inhibition may improve the sensitivity of A549/DDP cells to cisplantin though modulating the Noxa expression.