[Cellar senescence and tumor].

Cells withdrawing from the cell cycle and entering the terminally non-dividing state are referred senescence. With few exceptions,normal cells necessarily enter this process. Molecular analyses have identified some changes in gene expressions as cells become senescent, including repression of positive-acting transcriptional regulators, over-expression of CDK inhibitor, and interference with downstream pathways, and changes in telomere and telomerase. Current findings show that senescence is well connected with tumorigenesis and tumor therapy. Studies with cell types other than fibroblast will better define the roles of cellar senescence in tumorigenesis, moreover, it may provide a novel therapeutic approach to tumor repression.