p16基因甲基化在人二倍体成纤维细胞衰老中的作用  

The role of p16 methylation in the aging of human fetal lung diploid fibroblasts

作　　者：陈培利[1] 童坦君[1] 张宗玉[1] 

机构地区：[1]北京大学医学部生化与分子生物学系,100083

出　　处：《中华老年医学杂志》2001年第1期44-46,共3页Chinese Journal of Geriatrics

基　　金：国家重点基础研究发展规划资助项目!(G2 0 0 0 0 5 70 0 1;G19990 5 3 90 6);国家自然科学基金重点资助项目!(3 993 0 170 )

摘　　要：目的　研究DNA甲基化与衰老细胞中细胞周期负调控因子p16 MTS1/INK4a高表达的关系。　方法　应用甲基化敏感的DNA限制性内切酶与PCR相结合的方法 ,分析特定位点的甲基化状态。　结果　人胚肺二倍体成纤维细胞衰老过程中p16基因表达增高 ,中年细胞及衰老细胞中p16基因的表达水平分别约为年轻细胞的 3倍和 10倍。p16基因外显子Ⅰ限制性内切酶SmaⅠ位点的甲基化水平则表现出随增龄而降低的趋势 ,在年轻细胞、中年细胞中分别约为 6 4%和 41% ,虽然在衰老细胞中仅为 2 4% ,但仍保持一定的水平。　结论　p16基因外显子Ⅰ的SmaⅠ位点的甲基化水平改变可能与其在衰老过程中的高表达有一定的关联 ,其重要性值得进一步研究。Objective The relationship between DNA methylation and the overexpression of cell cycle negative regulator p16 MTS1/INK4a in senescent cells was studied. Methods PCR amplification of p16 exon I following digestion with Sma I , a methylation sensitive DNA endonuclease, was adapted to determine the methylation status at specific site. Results T-he increased expression of p16 in the aging process of human fetal lung diploid fibroblasts (2BS) was observed. In middle aged and old cells, the p16 level was about 3 folds and 10 folds respectively as that in young cells. The methylation level of the Sma I site in p16 exon I tended to decline with aging, being about 64% and 41% in young and middle aged cells respectively, but still maintain relatively as high as about 24% in senescent cells. Conclusions The overexpression of p16 in senescent human fibroblasts might be related to the alteration of methylation level of exon I, its mechanisms need to be defined further.

关 键 词：P16基因 DNA甲基化 细胞衰老 衰老 

分 类 号：R339[医药卫生—人体生理学]