筛选机制与细胞衰老的DNA损伤假说 Selective Mechanisms and the DNA Injury Hypothesis of Cell Senescence

生物界存在一类筛选机制,它将DNA损伤较小的细胞筛选出来,产生后代.主要有两类模式机制1和机制2,分别以细菌和人的成纤维细胞为代表,那些具有筛选机制1的细胞(如:细菌、生殖细胞、癌细胞)能无限传代,而体细胞则不能.这两类筛选机制背后有更深刻的原因,而细胞的癌变正是从机制2退化为机制1的过程。 Abstract:Selective mechanisms exist in organism and biosphere,which select the cells with less DNA injuy and reproduces them.There are two models;Mechanisms 1 and Mechanisms 2,represented respectively b bacteria and mechanolytes of human beings.Cells with Mechanisms 1(e.g. bacteria,generative cells,cancer cells)can reproduce infinitely,while somatic cells can not.There are deep-going reasons behind the two categories of selective mechanisms.The canceration of the cells is a degenerating process from Mechanisms 2 to Mechanisms 1.