乳腺癌患者体内多环芳烃暴露水平及其代谢酶基因甲基化的研究

Study on the level of PAHs exposure and metabolism-related gene methylation in female patients with breast cancer

目的探讨乳腺癌患者外周血谷胱甘肽-S-转移酶P1(GSTPl)基因启动子区甲基化的意义,了解患者生活、饮食习惯、病理分型与多环芳烃负荷水平及GSTP1基因甲基化水平的关系。方法通过1∶1同民族、年龄相差±2岁配对的病例对照研究,选择入住于新疆某三甲医院的新疆常住各族女性原发性乳腺癌患者39例为病例组,无乳腺癌及肿瘤史的体检健康女性39例为对照组。收集患者晨尿和静脉血,采用液质联用法检测尿液中的多环芳烃代谢物的含量,焦磷酸测序法检测外周血中GSTP1基因启动子区甲基化。所获计数资料用χ^2检验或Fisher确切概率法进行统计分析,非正态计量资料进行配对秩和检验。结果病例组食用腌制、烧烤类食物人数占比较高(P<0.05);病例组初潮年龄较对照组更偏向年轻化(P<0.05)。尿中多环芳烃代谢产物检测结果显示,病例组尿中的1-羟基芘、9-羟基菲、2-羟基萘及1-羟基萘水平高于对照组(P<0.05)。尿中的2-羟基芴在乳腺癌患者的人表皮生长因子受体2(Her-2)阴性组与阳性组之间差异有统计学意义(P<0.05)。三阴乳腺癌与非三阴乳腺癌患者尿中9-羟基菲、2-羟基芴的浓度差异有统计学意义(P<0.05)。孕激素受体(PR)阴性组与阳性组的GSTP1 PM00151816 CPG-1甲基化程度差异有统计学意义,Her-2阴性与阳性组的GSTP1 PM00151816 CPG-3、CPG-4甲基化程度差异有统计学意义。结论体内多环芳烃的负荷可能与乳腺癌的发生有关,GSTPl基因CPG的甲基化可为不同分子分型乳腺癌的治疗与预后提供补充和参考。

Objective To investigate the significance of methylation in GSTP1 gene promoter region in peripheral blood of breast cancer patients,and to understand the relationship between lifestyle,diet patho logical typing and PAH load level,and GSTP1 gene methylation level in patients with breast cancer.Methods Thirty-nine female breast cancer patients without medical history of other cancers were collected as case group,whilethirty-nine healthy females as the control group were matched with the case group according to same ethnic and age(±2 years).Morning urine and venous blood of the patients were collected,and the contents of PAHs metabolites in urine were detected by liquid mass spectrometry,and the GSTP1 promoter methylation in peripheral blood was detected by pyrosequencing.Statistical analysis was performed by chi-square test or Fisher's exact probability test,and the non-normal measurement data were tested by paired rank sum test.Results The frequency of eating salted food and barbecue was higher in the case group(P<0.05).The age of menarche in the case group was smaller(P<0.05).The results of urine polycyclic aromatic hydrocarbon metabolites showed that the urine levels of 1-hydroxypyrene 9-hydroxyphenyl,2-hydroxynaphthalene and 1-hydroxynaphthalene in the case group were higher than those in the control group(P<0.05).There was a statistical difference between 2-hydroxyfluorene in urine in human epidermal growth factor receptor 2(HER-2)negative group and positive group in the breast cancer patients(P<0.05).There was a statistical difference in the concentration of 9-hydroxyfluorene in urine in patients with triple negative breast cancer and non-triple negative breast cancer(P<0.05).The methylation level of GSTP1 PM00151816CPG-1 in the negative and positive groups of progesterone receptor(PR)was statistically significant,while the methylation level of GSTP1 PM00151816 CPG-3,CPG-4 in the negative and positive groups of HER-2 was statistically significant.Conclusion The load of PAHs in the body may be related to the occurrence of breast cancer,and the methylation of GSTPl gene CPG may provide a supplement and reference for the treatment and prognosis of different molecular types of breast cancer.