METHODS: Proliferation and apoptosis of DDP-resistant NSCLC cells were detected using cell counting kit-8 and flow cytometry assays. The interaction between SH3PXD2A-AS1 and sirtuin 7 (SIRT7) was assessed using co-immunoprecipitation (Co-IP), RNA pull-down, RNA immunoprecipitation (RIP), RNA fluorescence in situ hybridization, and immunofluorescence assays, while succinylation (SUCC) of Forkhead Box M1 (FOXM1) was analyzed by IP and Western blot assays. The role of SH3PXD2A-AS1 in vivo was explored using a xenografted tumor model.
RESULTS: Expression of SH3PXD2A-AS1 was found elevated in DDP-resistant NSCLC cells, while it\'s knocking down translated into suppression of cell viability and promotion of apoptosis. Moreover, silencing of SH3PXD2A-AS1 resulted in decreased FOXM1 protein level and enhanced FOXM1-SUCC protein level. The SIRT7 was found to interact with FOXM1, translating into inhibition of FOXM1 SUCC at the K259 site in human embryonic kidney (HEK)-293T cells. Overexpressing of SIRT7 reversed the increase of FOXM1-SUCC protein level and apoptosis, and the decrease of cell viability induced by silencing of SH3PXD2A-AS1. In tumor-bearing mice, SH3PXD2A-AS1 inhibition suppressed tumor growth and the protein levels of Ki67, SIRT7, and FOXM1.
CONCLUSIONS: SH3PXD2A-AS1 promoted DDP resistance in NSCLC cells by regulating FOXM1 SUCC via SIRT7, offering a promising therapeutic approach for NSCLC.
方法:使用细胞计数试剂盒-8和流式细胞术检测DDP抗性NSCLC细胞的增殖和凋亡。SH3PXD2A-AS1和沉默蛋白7(SIRT7)之间的相互作用使用免疫共沉淀(Co-IP)进行评估,RNA下拉,RNA免疫沉淀(RIP),RNA荧光原位杂交,和免疫荧光分析,而叉头盒M1(FOXM1)的琥珀酰化(SUCC)通过IP和Western印迹分析。使用异种移植肿瘤模型探索了SH3PXD2A-AS1在体内的作用。
结果:发现SH3PXD2A-AS1在DDP耐药的NSCLC细胞中表达升高,而它的敲除转化为抑制细胞活力和促进细胞凋亡。此外,沉默SH3PXD2A-AS1导致FOXM1蛋白水平降低,FOXM1-SUCC蛋白水平升高。发现SIRT7与FOXM1相互作用,在人胚肾(HEK)-293T细胞中K259位点转化为FOXM1SUCC的抑制。SIRT7的过表达逆转了FOXM1-SUCC蛋白水平的升高和细胞凋亡,和沉默SH3PXD2A-AS1诱导的细胞活力降低。在荷瘤小鼠中,SH3PXD2A-AS1抑制抑制肿瘤生长和Ki67、SIRT7和FOXM1的蛋白水平。
结论:SH3PXD2A-AS1通过SIRT7调节FOXM1SUCC促进NSCLC细胞对DDP的耐药,为NSCLC的治疗提供了一种有希望的方法。