结直肠癌P53突变状态与细胞命运决定子Numb表观遗传表达相关性研究  

Relationship between p53 mutation status and numb epigenetic expression in colorectal cancer

作　　者：张辉[1] 叶颖江[1] 周静[1] Zhang Hui;Ye Yingjiang;Zhou Jing(Department of Gastroenterology Surgery,Peking University People′s Hospital,Beijing 100044,China)

机构地区：[1]北京大学人民医院胃肠外科,100044

出　　处：《中华实验外科杂志》2021年第12期2414-2417,共4页Chinese Journal of Experimental Surgery

基　　金：科技部国家重点研发项目(2017YFC0908300)。

摘　　要：目的结直肠癌组织标本中Numb甲基化状况,p53基因的突变情况,探讨p53突变与Numb/Notch1表达模式的关系。方法分别采用甲基化特异性的聚合酶链反应(MSP)检测Numb基因启动子区甲基化状况、聚合酶链反应(PCR)及DNA测序检测p53基因突变状况,采用固定化蛋白质印迹法(Western blot)检测Numb在60例切除结直肠癌组织中的表达,分析p53突变状态与Numb表达水平的相关性,研究两者表达模式关系与表观遗传关系。结果60例结直肠癌组织中Numb基因启动子甲基化状况,与正常肠黏膜组织比较,其中25例(41.7%)结直肠癌组织Numb基因启动子呈部分甲基化,但与其mRNA及蛋白表达并无明显相关性(P>0.05)。60例患者中31例存在p53基因突变,突变率为51.7%,外显子(E)5、6、7、8的突变次数分别为5、6、12、11例次(其中有2例检出E7、E82个外显子突变,1例为E5、E82个外显子突变),Numb在p53突变组表达水平(0.45±0.13)显著低于非突变组(0.87±0.12,P<0.05)。p53突变与Numb蛋白表达呈线性负相关,相关系数为-0.69,p53突变与Notch1蛋白表达呈线性正相关,相关系数为0.33,而与Delta及Jagged1蛋白表达无明显相关。Numb低表达(39例)预后差于Numb高表达患者(21例),差异有统计学意义(P<0.05)。结论p53突变状态与Numb表达水平密切相关,有助于判断结直肠癌某些生物学行为及预后。Objective To study the status of numb methylation and p53 gene mutation in colorectal cancer tissues,and to analyze the relationship between p53 mutation and numb/Notch1 expression pattern.Methods Methylation specific PCR(MSP)was used to detect the methylation status of the promoter region of numb gene.Polymerase chain reaction(PCR)and DNA sequencing were used to analyze the mutation of p53.The expression of numb in 60 cases of colorectal cancer was detected by blot.The correlation between p53 mutation status and numb expression level,the relationship between the expression pattern of p53 and clinicopathological parameters of colorectal cancer,and the relationship between the expression of numb and the survival of patients were studied.Results Compared with normal intestinal mucosa,25(41.7%)colorectal cancer tissues showed partial methylation of numb gene promoter,but there was no correlation between numb gene promoter methylation and mRNA and protein expression(P>0.05).P53 gene mutation was found in 31 of 60 patients,with the mutation rate of 51.7%,and exon(E)5,6,7,8 The number of mutations in exons E7 and E8 was 5,6,12 and 11(including 2 exons E7 and E8 mutations in 2 cases,and exon E5 and E8 in 1 case).The expression level of numb in p53 mutation group was significantly lower than that in non mutation group(P<0.05)(see table 2.5).There was a negative linear correlation between p53 mutation and numb protein expression,with a correlation coefficient of-0.69.There was a positive linear correlation between p53 mutation and Notch1 protein expression(correlation coefficient was 0.33),but there was no significant correlation between p53 mutation and delta and Jagged1 protein expression.The prognosis of patients with low expression of numb(39 cases)was worse than that of patients with high expression of numb(21 cases)(P<0.05),and the difference was statistically significant(P<0.05).Conclusion p53 mutation status is closely related to numb expression level,which can be used as a new reference index for some biological

关 键 词：结直肠肿瘤 P53抑癌基因 细胞命运决定子Numb 突变 相关 

分 类 号：R735.34[医药卫生—肿瘤]