精脒/精胺N1-乙酰转移酶2调控胰腺癌细胞化疗耐药的机制  

Mechanisms of spermidine/spermine N1-acetyltransferase 2 in the chemoresistance of pancreatic cancer to gemcitabine

作　　者：刘鑫鑫 陈凯 龙迪 褚翔宇 邵志江[2] 张树鹏 杨尹默[1] 田孝东[1] Liu Xinxin;Chen Kai;Long Di;Chu Xiangyu;Shao Zhijiang;Zhang Shupeng;Yang Yinmo;Tian Xiaodong(Department of General Surgery,Peking University First Hospital,Beijing 100034,China;Department of General Surgery,Tianjin Fifth Centre Hospital,Tianjin 300450,China)

机构地区：[1]北京大学第一医院普通外科,100034 [2]天津市第五中心医院普通外科,300450

出　　处：《中华实验外科杂志》2022年第7期1296-1298,共3页Chinese Journal of Experimental Surgery

基　　金：国家自然科学基金(81672353、81871954);北京市自然科学基金(7212111);天津市医学重点学科(专科)建设项目。

摘　　要：目的探讨精脒/精胺N1-乙酰转移酶2(SSAT2)对胰腺癌细胞吉西他滨化疗耐药的影响及其分子机制。方法利用梯度浓度法构建耐药细胞株MiaPaCa-2 GR和PANC-1 GR,蛋白印迹法检测耐药前后细胞中SSAT2及铁死亡标志物谷胱甘肽过氧化物酶4(GPX4)的表达变化;慢病毒载体构建稳定过表达SSAT2的耐药细胞株;细胞计数试剂盒(CCK-8)检测各组细胞对吉西他滨敏感性的变化;丙二醛(MDA)检测细胞内脂质过氧化水平变化。两组间比较采用t检验,多组间比较采用单因素方差分析。结果两种耐药细胞株中SSAT2表达高于野生型细胞株[(0.692±0.026)倍比(0.953±0.132)倍,t=3.360,P<0.05;(0.581±0.036)倍比(0.751±0.080)倍,t=3.356,P<0.05],而铁死亡负调控标志物GPX4在两种耐药细胞株中均显著升高[(2.295±0.753)、(52.794±1.680)倍,t=4.013、10.701,P<0.05]。上调SSAT2后耐药细胞胰腺癌株对吉西他滨的敏感性高于对照组[(0.047±0.017)μmol/L比(1.507±0.283)μmol/L,t=8.920,P<0.01;(0.216±0.063)μmol/L比(2.238±0.582)μmol/L,t=5.983,P<0.01],且铁死亡抑制剂ferr-1处理过表达SSAT2组细胞对吉西他滨的耐药性提高[(1.019±0.193)、(1.633±0.482)μmol/L,t=8.689、5.049,P<0.05],同时MDA水平低于过表达SSAT2组[(2.298±0.099)、(1.986±0.269)倍,t=3.908、6.430,P<0.05]。过表达SSAT2组GPX4蛋白表达水平显著低于对照组[(0.453±0.040)倍比(1.086±0.094)倍,t=10.732,P<0.01;(0.236±0.045)倍比(1.337±0.479)倍,t=3.964,P<0.05]。结论SSAT2通过抑制GPX4蛋白水平促进铁死亡,增强胰腺癌细胞化疗敏感性。Objective To explore the mechanism of spermidine/spermine N1-acetyltransferase 2(SSAT2)in the chemoresistance of pancreatic cancer to gemcitabine.Methods Low doses treated gradually pancreatic cancer cell lines to construct gemcitabine-resistant pancreatic cancer cell lines,MiaPaCa-2 GR and PANC-1 GR.The expression of SSAT2 and glutathione peroxidase 4(GPX4)was detected by Western blotting.Lentiviruses were used to construct drug-resistant cell lines stably overexpressing SSAT2.Cell counting kit-8(CCK-8)method was used to assess the sensitivity to gemcitabine in groups and malondialdehyde(MDA)was detected to evaluate lipid peroxidation levels.T test was used to compare the mean between two groups,and the one-way ANOVA was used to compare multiple groups.Results The expression of SSAT2 was higher in the two drug-resistant cell lines[(0.692±0.026)times vs.(0.953±0.132)times,t=3.360,P<0.05;(0.581±0.036)times vs.(0.751±0.080)times,t=3.356,P<0.05],while GPX4 was increased in the two drug-resistant cell lines[(2.295±0.753),(52.794±1.680)times,t=4.013,10.701,P<0.05].The sensitivity of drug-resistant cell lines with up-regulation of SSAT2 to gemcitabine was higher than that of the control group[(0.047±0.017),(0.216±0.063)μmol/L,t=8.920,5.983,P<0.01],and the ferrostatin-1 decreased the sensitivity to gemcitabine[(1.019±0.193),(1.633±0.482)μmol/L,t=8.689,5.049,P<0.05],while the level of MDA was lower than that in the overexpression SSAT2 group[(2.298±0.099),(1.986±0.269)times,t=3.908,6.430,P<0.05].The expression level of GPX4 protein in the SSAT2 overexpression group was lower than that in the control group[(0.453±0.040)times vs.(1.086±0.094)times,t=10.732,P<0.01;(0.236±0.045)times vs.(1.337±0.479)times,t=3.964,P<0.05].Conclusion SSAT2 can restore the sensitivity of drug-resistant pancreatic cancer cells by inhibiting GPX4 to induce ferroptosis.

关 键 词：精脒/精胺N1-乙酰转移酶2 胰腺癌 铁死亡 吉西他滨 

分 类 号：R735.9[医药卫生—肿瘤]