弥漫大B细胞淋巴瘤中RASSF2A基因甲基化分析及其临床意义研究

发布时间：2018-06-25 20:46

本文选题：淋巴瘤 + 表观遗传学　；参考：《河北医科大学》2016年硕士论文

【摘要】：目的:淋巴瘤是最早发现的血液系统恶性肿瘤之一,近年来其发病率呈上升趋势,虽然淋巴瘤的治疗方法不断改善,经过联合化疗后得以延长半数以上患者的生存期,但仍然有部分患者死于肿瘤的进展。因此关注淋巴瘤病因学研究、早期诊断及靶向治疗是十分必要的。近年来,越来越多的研究表明表观遗传在肿瘤的发生发展过程中起到重要作用,而DNA甲基化水平改变是目前研究最为广泛的表观遗传学机制之一。RASSF2是RASSF家族中的一员,是一种抑癌基因。RASSF2包括RASSF2A、RASSF2B和RASSF2C三个转录本。其中RASSF2A具有促进细胞凋亡和抑制生长作用,同时它还能抑制炎症因子表达,达到抑制肿瘤浸润的目的。有研究发现,在结肠癌、结肠癌细胞系以及结肠腺瘤中RASSF2A基因启动子区普遍存在高甲基化,而在胃癌、子宫内膜癌、鼻咽癌、肺癌中也能检测到RASSF2A启动子区甲基化现象的发生。甲基化是导致RASSF2A基因失活的重要机制。但至今,RASSF2A在弥漫大B细胞淋巴瘤中的相关研究尚未见报道。本研究采用逆转录-聚合酶链反应(Reverse Transcriptase-PCR,RT-PCR)和甲基化特异性聚合酶链反应(Methylation-Specific PCR,MSP)的方法,以正常人外周血为对照,检测弥漫大B细胞淋巴瘤患者外周血中的RASSF2A基因甲基化状态及m RNA表达情况,并结合相应的临床资料分别作相关性分析,为弥漫大B细胞淋巴瘤的发病机制、临床诊断及治疗提供一定的理论依据。方法:1应用MSP检测弥漫大B细胞淋巴瘤患者外周血以及正常人外周血的RASSF2A基因甲基化状态,并分析该基因甲基化与临床资料之间的关系。2应用RT-PCR检测弥漫大B细胞淋巴瘤患者外周血以及正常人外周血的RASSF2A基因m RNA的相对表达量,并分析该基因m RNA相对表达量与临床资料之间的关系。3采用SPSS 19.0软件对数据进行统计学分析。结果:1 RASSF2A基因在弥漫大B细胞淋巴瘤患者外周血中甲基化率为42.5%(17/40),显著高于正常人外周血的甲基化率10.0%(4/40),差异有统计学意义(P0.05)。RASSF2A基因在弥漫大B细胞淋巴瘤患者的外周血中的甲基化与患者的Ki-67、结外累及与否以及LDH相关,与正常人外周血相比,差异有统计学意义(P0.05);与患者的IPI评分、骨髓累及与否、年龄、性别、A/B症状、生发中心或非生发中心、β2微球蛋白以及临床分期均无关,与正常人外周血相比,差异无统计学意义(P0.05)。2 RASSF2A基因在弥漫大B细胞淋巴瘤患者外周血中的m RNA表达量为0.49±0.13,明显低于在正常人外周血中的m RNA的表达量0.56±0.17,且差异有统计学意义(P0.05)。RASSF2A基因在弥漫大B细胞淋巴瘤患者外周血中m RNA的表达量与患者IPI评分、结外累及与否、Ki-67以及LDH相关的,与正常人对照组相比,差异有统计学意义(P0.05);与患者的A/B症状、年龄、性别、β2微球蛋白、生发中心或非生发中心、临床分期、骨髓累及与否均无关,差异无统计学意义(P0.05)。3弥漫大B细胞淋巴瘤患者的外周血中的RASSF2A基因启动子的检测结果表明其甲基化为阳性,其m RNA平均相对表达量为0.41±0.12,甲基化阴性的m RNA平均相对表达量为0.55±0.11,两者差异有统计学意义(P0.05)。结论:1弥漫大B细胞淋巴瘤患者外周血中RASSF2A的甲基化率明显高于正常对照组的甲基化率,提示RASSF2A基因启动子甲基化可能与弥漫大B细胞淋巴瘤发生相关。2弥漫大B细胞淋巴瘤患者外周血中RASSF2A基因m RNA的表达明显低于正常人对照组,提示RASSF2A基因可能在弥漫大B细胞淋巴瘤具有抑癌基因的作用。3弥漫大B细胞淋巴瘤患者外周血中RASSF2A基因启动子呈高甲基化,其m RNA表达降低,提示弥漫大B细胞淋巴瘤中RASSF2A基因甲基化可能与其m RNA表达降低有关。4弥漫大B细胞淋巴瘤患者外周血中,RASSF2A基因启动子甲基化与患者的结外累及与否、Ki-67和LDH相关,提示RASSF2A基因启动子甲基化可作为评价弥漫大B细胞淋巴瘤的恶性进程、侵袭性以及预后的指标。
[Abstract]:Objective: lymphoma is one of the earliest found malignant tumors of the blood system. In recent years, the incidence of lymphoma is on the rise. Although the treatment method of lymphoma is continuously improved, the survival period of more than half of the patients can be prolonged after combined chemotherapy, but some patients still die of the progress of the tumor. Therefore, attention is paid to the etiology of lymphoma. Diagnosis and targeted therapy are very necessary. In recent years, more and more studies have shown that epigenetic inheritance plays an important role in the development of tumor. The change of DNA methylation level is one of the most widely studied epigenetic mechanisms,.RASSF2 is a member of the RASSF family, and a tumor suppressor gene,.RASSF2, including RASSF2 Three transcripts of A, RASSF2B and RASSF2C, in which RASSF2A can promote cell apoptosis and inhibit growth, and also inhibit the expression of inflammatory factors to inhibit tumor infiltration. The methylation of RASSF2A promoter region can also be detected in endometrial carcinoma, nasopharyngeal carcinoma, and lung cancer. Methylation is an important mechanism leading to the inactivation of RASSF2A gene. But up to now, the related research of RASSF2A in diffuse large B cell lymphoma has not been reported. This study uses reverse transcriptase polymerase chain reaction (Reverse Transcriptase-PCR, RT-). PCR) and methylation specific polymerase chain reaction (Methylation-Specific PCR, MSP), using normal human peripheral blood as the control, to detect the methylation status of RASSF2A gene and the expression of M RNA in peripheral blood of patients with diffuse large B cell lymphoma, and to combine the corresponding clinical data for the diffuse large B cell lymphoma. The pathogenesis, clinical diagnosis and treatment provided a certain theoretical basis. Methods: 1 MSP was used to detect the methylation of RASSF2A gene in peripheral blood of patients with diffuse large B cell lymphoma and normal human peripheral blood, and the relationship between methylation and clinical data was analyzed by.2 application RT-PCR to detect the peripheral blood of patients with diffuse large B cell lymphoma The relative expression of RASSF2A gene m RNA in blood and normal human peripheral blood, and analysis of the relationship between the relative expression of M RNA and the clinical data.3 using SPSS 19 software to analyze the data statistically. Results: the 1 RASSF2A gene was 42.5% (17/40) in the peripheral blood of the diffuse large B cell lymphoma patients, which was significantly higher than that of 42.5% (17/40). The methylation rate of peripheral blood of normal people was 10% (4/40). The difference was statistically significant (P0.05) the methylation of.RASSF2A gene in peripheral blood of patients with diffuse large B cell lymphoma was associated with the patient's Ki-67, extranodal involvement and LDH, and the difference was statistically significant (P0.05) compared with the normal peripheral blood (P0.05); and the IPI score of the patients, and bone marrow involvement. Whether age, sex, A/B symptoms, germinal center or non germinal center, beta 2 microglobulin and clinical staging were not related, compared with normal human peripheral blood, the difference was not statistically significant (P0.05), the amount of M RNA in peripheral blood of.2 RASSF2A gene in diffuse large B cell lymphoma was 0.49 + 0.13, significantly lower than that of M R in normal peripheral blood. The expression of NA was 0.56 + 0.17, and the difference was statistically significant (P0.05) in the peripheral blood of patients with diffuse large B cell lymphoma, the expression of M RNA was related to the IPI score, Ki-67 and LDH, and the difference was statistically significant compared with the normal control group (P0.05); A/B symptoms, age, sex, and beta 2 were compared with those of the control group. Microglobulin, germinal center or non germinal center, clinical staging and bone marrow involvement were not related, and the difference was not statistically significant (P0.05) the detection of RASSF2A gene promoter in peripheral blood of patients with.3 diffuse large B cell lymphoma showed that the methylation was positive, the average relative expression of M RNA was 0.41 + 0.12, and the methylation negative m RNA The mean relative expression was 0.55 + 0.11, and the difference was statistically significant (P0.05). Conclusion: the methylation rate of RASSF2A in peripheral blood of patients with 1 diffuse large B cell lymphoma was significantly higher than that of normal control group, suggesting that the methylation of RASSF2A gene promoter may be associated with the diffuse large B cell lymphoma of.2 diffuse large B cell lymphoma. The expression of RASSF2A gene m RNA in peripheral blood of patients was significantly lower than that in normal controls, suggesting that the RASSF2A gene might be in the diffuse large B cell lymphoma with tumor suppressor gene, the promoter of RASSF2A gene promoter in the peripheral blood of.3 diffuse large B cell lymphoma was hypermethylation, and the m RNA expression decreased, suggesting that the diffuse large B cell lymphoma was RASSF. The methylation of 2A gene may be associated with the decrease in the expression of M RNA expression in peripheral blood of patients with.4 diffuse large B cell lymphoma. RASSF2A gene promoter methylation is associated with Ki-67 and LDH, which suggests that the RASSF2A gene promoter methylation may be used to evaluate the malignant progression, invasiveness, and prognosis of diffuse large B cells. Mark.
【学位授予单位】：河北医科大学
【学位级别】：硕士
【学位授予年份】：2016
【分类号】：R733.1

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