基于多肽微阵列探索胶质母细胞瘤MGMT自身抗体在化疗中的价值

The key impact of glioblastoma (GBM) preferred chemotherapy temozolomide (TMZ) efficacy is O6-methylguanine DNA methyltransferase (MGMT). Since the application of MGMT promoter methylation and MGMT protein to determine the resistance of GBM have limitations, there is an urgent need for studying MGMT targeted drug therapy and for new technology to determine resistance of GBM patients before and during treatment. Our previous study found that: MGMT peptide autoantibodies have higher responsivity in serum of GBM patients; there is a higher correlation with tumor MGMT expression and MGMT methylation results. In hence, we propose MGMT autoantibodies of GBM patients objectively reflect resistance to TMZ. Focusing on MGMT molecular structure and activity area analysis, inhibiting the activity of MGMT is expected to improve the efficacy of TMZ. To test this hypothesis, the project will expand the GBM tumor specimens and serum of patients, use peptide microarray technology, immunohistochemistry and MSP to do tumor drug resistence correlation analysis. Clinical data will be collected at the same time to determine the clinical value of peptide microarray technology in judging GBM drug resistance. By using amino acid point mutation technology, MGMT protein activity detection experiments, we will further study which MGMT gene sequences function. This study used new technology to determine whether the GBM patients are resistant to TMZ from new perspective of autoantibodies, and provide the scientific basis in determining a reasonable choice of individual chemotherapy and in studying MGMT targeted drug therapy.

影响替莫唑胺(TMZ)治疗胶质母细胞瘤(GBM)疗效的关键是O6-甲基鸟嘌呤DNA甲基转移酶(MGMT)，用MGMT基因启动子甲基化和蛋白表达判断GBM耐药性存在不足。我们前期研究发现多肽微阵列检测血清MGMT自身抗体在GBM中有较高响应度，与MGMT甲基化和蛋白表达密切相关。为此，我们提出患者MGMT自身抗体能反映肿瘤的耐药性，聚焦MGMT分子结构和活性区解析，抑制MGMT活性可显著提高TMZ疗效。为验证此假设，我们将扩大GBM样本，运用多肽微阵列、甲基化特异性PCR和免疫组化分别检测MGMT自身抗体、启动子甲基化和蛋白表达，同时收集临床资料进行相关性分析，明确MGMT自身抗体在TMZ治疗GBM中的重要价值。进一步运用点突变技术，蛋白活性检测等，确定MGMT作用的活性区。本研究从MGMT自身抗体新视角判断GBM对TMZ耐药性，为临床正确选择个体化疗方案及为开发靶向MGMT药物提供新思路。

影响替莫唑胺(TMZ)治疗胶质母细胞瘤(GBM)疗效的关键是O6-甲基鸟嘌呤DNA甲基转移酶(MGMT)。由于MGMT启动子甲基化和MGMT蛋白在确定GBM耐药性方面的应用存在局限性，因此迫切需要研究针对MGMT的靶向药物治疗以及在治疗之前和期间确定GBM患者耐药性的新技术。我们前期研究发现多肽微阵列检测血清MGMT自身抗体在GBM中有较高响应度，与MGMT甲基化和蛋白表达密切相关。为此，我们提出患者MGMT自身抗体能反映肿瘤的耐药性。在本课题中，聚焦MGMT分子结构和活性区解析，研究血清O-6-甲基鸟嘌呤-DNA甲基转移酶（MGMT）自身抗体作为新型标记物的临床效用，通过MGMT肽微阵列预测胶质瘤的复发和治疗反应。. 我们在脑胶质瘤患者的血清中检测到了针对MGMT肽的自身抗体，并且在脑胶质瘤组中鉴定出了五种对肽具有高响应性的自身抗体。将胶质瘤组中MGMT自身抗体对20种肽的阳性率与健康个体进行比较，MGMT-02（45％）的阳性率，胶质瘤患者中MGMT-04（27％），MGMT-07（21％），MGMT-10（13％）和MGMT-18（24％）显着升高。MGMT自身抗体及其蛋白表达表现出显着的相关性。MGMT自身抗体水平在术后30天下降，达到术前水平，与肿瘤复发时相似。单变量和多变量分析显示，MGMT-02肽的唯一术前自身抗体与无复发生存率呈相关性。术前血清阳性患者比血清阴性患者更有可能具有较短的复发时间，并且对放化疗或替莫唑胺治疗具有耐药性。. 因此，监测术前针对MGMT-02肽的血清自身抗体的水平有助于预测复发和治疗反应的高风险患者。