丙戊酸钠在体内外影响NK细胞对人肺癌细胞杀伤作用的研究

The effect of valproic acid on the NK killing effects to the human lung cancer cell line in vitro and in vivo

目的观察丙戊酸钠(valproic acid,VPA)对人肺癌细胞A549、SP-CA-1、NCIH446中的MHCⅠ类链相关基因A(MICA)表达的影响,并比较经VPA处理前后NK细胞对肺癌细胞杀伤作用的差异,及肺癌荷瘤小鼠动物模型瘤组织重量、大小的差异。方法将0.75～12.0mmol/L VPA作用于A549、SP-CA-1、NCIH446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1.50mmol/L和3.00mmol/L VPA诱导三株肺癌细胞4d,通过RT-PCR反应检测MICA在mRNA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。建立肺癌荷瘤小鼠动物模型,加入不同剂量VPA,体内观察VPA对肺癌瘤组织重量、大小的影响。结果用1.50mmol/L和3.00mmol/L VPA诱导4d后的三株肺癌细胞,与对照组比较,其MICA的mRNA转录水平提高,被NK杀伤的程度提高(P<0.05);高VPA浓度组三株肺癌细胞的mRNA水平及其被NK细胞杀伤的程度均高于低浓度组(P<0.05);VPA高剂量和/或低剂量组抑制荷瘤鼠皮下肿瘤的生长作用与对照组差异有统计学意义,P<0.05,抑瘤率分别为52.9%和35.9%。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,具有治疗肺癌的潜在价值,VPA在体内对肺癌细胞A549的增殖也存在明显的抑制作用,为探讨肺癌治疗新方法及其机制提供一个新途径。

Objective To investigate the infulence of valproic acid（VPA）in MICA gene expression in human lung carcinoma cells： A549,SP-CA-1,NCIH446,the infulence of valproic acid（VPA）in NK cell＇s killing effect in lung carcinoma cell and the difference of weight,size of tumor tissue in lung cancer tumor-burdened mice animal models.Methods 0.75～12.0mmol/ L of VPA were applied to treat A549、SP-CA-1、NCIH446 cells.We observed the infulence of the VPA in the growth of lung carcinoma cells,compared to the untreated cells as the control group.RT-PCR was used to detect the changes of mRNA of MICA gene in three kinds of human lung carcinoma cells treated with 1.5mmol/L and 3.00mmol/L VPA for 4 days.The method of LDH was used to detect the difference of NK cells＇ killing effect in lung carcinoma cells before and after the treatment of VPA.Lung cancer tumor-burdened mice models was established to investigate the infulence of the VPA in weight,size of tumor tissue.Results The VPA inhibited the growth of three kinds of lung cancer cells above the concentration of 6.0 mmol/L.Compared to the control group,the transcription level of mRNA of MICA gene were increased in the three kinds of human lung carcinoma cells treated with 1.5mmol/L and 3.00mmol/L VPA for 4 days.Difference was statistically significant for P〈0.05.Higher degree of NK cells＇killing effect in lung cancer cells which was inducted to express MICA by 1.50mmol/L and 3.00mmol/L VPA was observed,Compared to the control group.Difference was statistically significant for P〈0.05.High VPA concentration group of lung cancer cells＇ mRNA and the extent of the damage by NK cells were higher than low concentration group.Difference was statistically significant for P〈0.05.The inhibiting effect in the growth of tumor-burdened rat＇s subcutaneous tumor was significant in high VPA dose and/or low dose group,compared to the control group.Difference was statistically significant for P〈0.05.The rates of inhibit of human lung cancer was 52.9% in high VPA dose group and 35.9% in low VPA dose group.Conclusion VPA induce the expression of MICA,NK killing effect in the VPA（＋） treatment lung cancer cells was significantly stronger than that of VPA（-） condition.VPA also can inhibit the increase of lung cancer cell A549 in vivo.Also it implied a new mechanism of anti-cancer method and new approach to cancer therapy.