SLFN11甲基化是人结直肠癌预后不良和对顺铂耐药的标志物

发布时间：2018-06-19 01:09

本文选题：SLFN11 + 甲基化　；参考：《中国人民解放军医学院》2017年博士论文

【摘要】：背景:结直肠癌是常见的恶性肿瘤,在世界范围内发病率排第三位,因癌致死率排第四位。结直肠癌在年轻人中少见,50岁以后发病率明显增高,在发达国家中位发病年龄为70岁。在中国,随着人们生活方式和饮食结构的改变,结直肠癌的发病率在逐年增高。大多数散发的结直肠癌病例(约85%)有染色体不稳定,包括染色体的等位基因失衡、染色体扩增和易位。DNA损伤修复和检查点调控机制缺陷是造成基因突变和染色体不稳定的重要机制。遗传性结直肠癌主要包括家族性腺瘤性息肉病和Lynch综合征,是由DNA错配修复基因突变引起的,小于结直肠癌发病率的5%。DNA损伤修复基因异常甲基化是结直肠癌的重要病因之一。在1998年,Schlafen ( SLFN )基因家族首先由Steven Hedrick等发现。到目前为止,已有10个鼠源性和6个人源性家族成员被鉴定。SLFN家族蛋白被报道参与一系列细胞生物学功能,包括增殖、分化和免疫功能。SLFN11基因是SLFN基因家族成员之一,被报道能够增加DNA损伤类药物的敏感性。到目前为止,SLFN11基因在人结直肠癌中的表观遗传学调控机制仍不清楚,需要进一步研究。目的:研究SLFN11基因在人结直肠癌中的表观遗传学改变和对化疗药物敏感性的研究。材料和方法:本研究在6种结肠癌细胞和128例人结直肠癌标本中进行了研究。在结肠癌细胞系中,采用RT-PCR、甲基化特异的PCR和硫化测序等方法研究了SLFN11受甲基化调控的机制。采用甲基化特异的PCR研究了人结直肠癌标本中SLFN1甲基化情况。采用MTT、克隆形成、流式细胞术和蛋白印迹法研究了 SLFN11对结肠癌细胞增殖的影响。采用裸鼠成瘤模型探讨了在体内SLFN11对结肠癌细胞增殖的影响。在结肠癌细胞中,采用MTT、流式细胞术对SLFN11与顺铂的敏感性进行了研究。结果:SLFN11启动子区附近在结直肠癌中经常发生甲基化(55.47%, 71/128)。SLFN11基因的表达受到甲基化调控。SLFN11基因甲基化与年龄、5年生存率和5年肿瘤复发时间相关。SLFN11在体内和体外都能抑制结肠癌细胞的增殖。SLFN11能够增强结肠癌细胞对顺铂的敏感性。
[Abstract]:Background: colorectal cancer is a common malignant tumor. The incidence of colorectal cancer increased significantly after 50 years of age in young people, with a median onset age of 70 years in developed countries. In China, the incidence of colorectal cancer increases year by year as people's lifestyle and diet change. Most sporadic cases of colorectal cancer (about 85) have chromosomal instability, including allelic imbalances in chromosomes, Chromosome amplification and translocation. DNA damage repair and checkpoint regulatory defects are the important mechanisms of gene mutation and chromosome instability. Hereditary colorectal cancer mainly includes familial adenomatous polyposis and Lynch syndrome, which is caused by mutation of DNA mismatch repair gene. Abnormal methylation of DNA damage repair gene is one of the important causes of colorectal cancer. In 1998, the Schlafen (SLFN) gene family was first discovered by Steven Hedrick et al. So far, 10 murine and 6 individual origin family members have been identified as involved in a series of cellular biological functions, including proliferation, differentiation and immune function. SLFN11 gene is a member of the SLFN gene family. It has been reported to increase the sensitivity of DNA damage drugs. Up to now, the epigenetic regulation mechanism of SLFN11 gene in human colorectal cancer is still unclear and needs further study. Aim: to study the epigenetic changes and chemosensitivity of SLFN11 gene in human colorectal cancer. Materials and methods: six kinds of colon cancer cells and 128 human colorectal cancer specimens were studied. In colon cancer cell line RT-PCR, methylation specific PCR and vulcanization sequencing were used to study the mechanism of SLFN11 methylation. The methylation of SLFN1 in human colorectal cancer was studied by methylation specific PCR. The effects of SLFN11 on the proliferation of colon cancer cells were studied by MTT, clone formation, flow cytometry and Western blotting. The effects of SLFN11 on the proliferation of colon cancer cells were studied in nude mice. MTT and flow cytometry were used to study the sensitivity of SLFN11 and cisplatin in colon cancer cells. Results 55.47 methylation occurs frequently in colorectal cancer near the 1: SLFN11 promoter region. The expression of 71 / 128U. SLFN11 gene is regulated by methylation. The methylation of SLFN11 gene is related to age, 5-year survival rate and 5-year recurrence time. SLFN11 can be expressed in vivo and in vitro. Inhibition of the proliferation of colon cancer cells. SLFN 11 can enhance the sensitivity of colon cancer cells to cisplatin.
【学位授予单位】：中国人民解放军医学院
【学位级别】：博士
【学位授予年份】：2017
【分类号】：R735.34

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