多胺
腐胺
CDKN2A
生物
癌症研究
细胞培养
细胞内
癌细胞
鸟氨酸脱羧酶
分子生物学
生物化学
癌症
酶
基因
遗传学
作者
Scott A. Christopher,Paula Diegelman,Carl W. Porter,Warren D. Kruger
出处
期刊:PubMed
日期:2002-11-15
卷期号:62 (22): 6639-44
被引量:142
摘要
The human methylthioadenosine phosphorylase (MTAP) gene is located on 9p21 and is frequently homozygously deleted, along with p16(cdkN2a/ARF), in a wide variety of human tumors and human tumor-derived cell lines. The function of MTAP is to salvage methylthioadenosine, which is produced as a byproduct of polyamine metabolism. We have reintroduced MTAP into MCF-7 breast adenocarcinoma cells and have examined its effect on the tumorigenic properties of these cells. MTAP expression does not affect the growth rate of cells in standard tissue culture conditions but severely inhibits their ability to form colonies in soft agar or collagen. In addition, MTAP-expressing cells are suppressed for tumor formation when implanted into SCID mice. This suppression of anchorage-independent growth appears to be because of the enzymatic activity of MTAP, as a protein with a missense mutation in the active site does not exhibit this phenotype. MTAP expression causes a significant decrease in intracellular polyamine levels and alters the ratio of putrescine to total polyamines. Consistent with this observation, the polyamine biosynthesis inhibitor alpha-difluoromethylornithine inhibits the ability of MTAP-deficient cells to form colonies in soft agar, whereas addition of the polyamine putrescine stimulates colony formation in MTAP-expressing cells. These results indicate that MTAP has tumor suppressor activity and suggest that its effects may be mediated by altering intracellular polyamine pools.
科研通智能强力驱动
Strongly Powered by AbleSci AI