西达本胺通过调控肿瘤相关巨噬细胞功能增强对结肠癌细胞的抑制作用

Chidamide enhances inhibitory effect on colon cancer cells by modulating tumor-associated macrophage

目的:探讨肿瘤相关巨噬细胞(TAM)对西达本胺(chidamide)抑瘤效果的影响及其作用机制。方法:体外培养小鼠巨噬细胞系Ana1和Raw264.7,用肿瘤上清诱导成为TAM。用西达本胺处理TAM后,用比色法检测HDAC酶活性,用q PCR检测TAM中IL-6、IL-12、TNF、IL-1β等细胞因子的m RNA表达水平,用Wb实验检测西达本胺处理后TAM中NF-κB和STAT3蛋白的表达水平。将TAM和结肠癌CT26细胞混合后,接种到裸鼠体内构建皮下移植瘤模型,灌喂西达本胺(3.87 mg/kg),观察西达本胺对皮下移植瘤生长的影响,并通过免疫组化检测移植瘤组织中PCNA、F4/80、Arg1、i Nos蛋白的表达水平。结果:西达本胺抑制CT26细胞的增殖活性,在裸鼠体内西达本胺单独处理CT26细胞皮下移植瘤的抑制率约为18.7%;当TAM存在时,西达本胺处理可以将移植瘤抑制率提高到57.2%。西达本胺可以抑制TAM的HDAC酶活性,进而使得组蛋白乙酰化水平升高;西达本胺能影响核内转录因子NF-κB水平,并且降低Arg1、IL-6、IL-12表达,提高iNos、Tnf、IL-1β表达。结论:西达本胺通过抑制TAM中HDAC活性和调控细胞因子表达,增强其对于结肠癌CT26细胞的抑制作用。

Objective:To investigate the effect of tumor-associated macrophage(TAM)on the anti-tumor function of chidamide and to explore the mechanism.Methods:Mouse macrophage cell lines Ana1 and Raw264.7 were cultured in vitro and induced into TAM with tumor supernatant.HDAC enzyme activity was detected after TAM treated with chidamide.The mRNA expressions of cytokines,such as IL-6,IL-12,TNF and IL-1β,in TAM were detected by q PCR.The protein expression of NF-κB and STAT3 in TAM treated with chidamide were detected by Wb.The mixture of TAM and colon cancer CT26 cells was inoculated into nude mice to construct the subcutaneous xenograft model;and the efficacy of chidamide(3.87 mg/kg)on the growth of CT26 xenograft tumors was observed.The protein expressions of PCNA,F4/80,Arg1 and iNos were detected by immunohistochemistry.Results:Chidamide inhibited the proliferation of CT26 cells.In the in vivo experiment,the inhibition rate of chidamide alone on CT26 xenograft was about 18.7%;however,the inhibition rate was up to 57.2%with the presence of TAM.Chidamide could inhibit the activity of HDAC enzyme in TAM,and further increase the Histone acetylation level.Chidamide could affect the expression of nuclear transcription factor NF-κB,inhibit the expressions of Arg1,IL-6 and IL-12,but up-regulate the expressions of iNOS,TNF and IL-1βin TAM.Conclusion:Chidamide can enhance its inhibitory effect on colon cancer CT26 cells via regulating the expression of cytokines and inhibiting the activity of HDAC in TAM.