丙戊酸钠诱导人肺癌细胞MICA表达上调增强NK细胞对其杀伤作用的研究

Valproic Acid Induce the Expression of MICA Antigen in Human Lung Cancer Cells and Promote the NK Killing Effects on the Cells

目的观察丙戊酸钠(valproic acid,VPA)对人肺癌细胞A549、SP-CA-1、NCI H446中的MHCⅠ类链相关基因A(MICA)表达的影响,并比较肺癌细胞经VPA处理前后NK细胞对其杀伤作用的差异。方法将0.75～12.0 mmol/L VPA作用于A549、SP-CA-1、NCI H446细胞,与未加VPA的对照组进行比较,观察VPA对人肺癌细胞生长的影响。选择对细胞生长无影响的1.50 mmol/L和3.00 mmol/L VPA诱导3株肺癌细胞4 d,通过RT-PCR反应和免疫荧光法分别检测MICA在mRNA和蛋白质水平的变化。LDH法检测VPA处理肺癌细胞前后其被NK细胞杀伤程度的变化。结果>6.0 mmol/L VPA对3株肺癌细胞均表现出抑制其生长。用1.50mmol/L和3.00 mmol/L VPA诱导4 d后的3株肺癌细胞,与对照组比较,其MICA的mRNA转录水平和蛋白质表达提高(P<0.05);1.50 mmol/L和3.00 mmol/L VPA诱导表达MICA后的肺癌细胞均比未经VPA处理的肺癌细胞被NK杀伤的程度高(P<0.05)。3.00 mmol/L VPA浓度组3株肺癌细胞的MICA mRNA、蛋白质表达水平及其被NK细胞杀伤的程度均高于1.50 mmol/L VPA浓度组(P<0.05)。结论VPA通过上调MICA抗肺癌作用的新机制,为肺癌临床免疫生物治疗提供了实验依据。

Objective To investigate the effect of valproic acid （VPA） on MICA gene expression in human lung carcinoma cell lines： A549, SP-CA-1, NCIH446. Methods Different concentration of VPA were applied to treat A549,SP-CA-1,NCIH446 cells respectively and the untreated cells as the control. The effect of the VPA on the cells were observed. Reverse Transcriptase PCR and Immune-Fluorescence staining were used to detect the changes of mRNA, protein level of MICA gene in the three cell lines treated with 1. 50 mmol/L and 3.00 mmol/L VPA for 4 days. under the concentration of VPA from 0.75 to 12.0 mmol/L. The viability of lung cancer cells after NK effect in the VPA （＋） and VPA （-） treatment were evaluated with LDH method. Results The inhibition effects were observed when the VPA concentration was 6.0 mmol/L above compared to control group, VPA induced the increasing expression of MICA and in turn enhanced the NK killing effect on the cells in a concentrationdepended pattern. Conclusion VPA induced MICA expression, NK killing effect in the VPA（＋） treatment lung cancer cells was significantly stronger than that of VPA（-） condition, which implied a new mechanism of anticancer method and could be a new approach to cancer therapy.