ABSTRACT
This chapter discusses several hypotheses concerning cellular senescence that derive from our work. Gene transfer and molecular cloning technologies represent powerful tools with which to gain new insights into the molecular mechanisms that underlie the aging process. Alterations in DNA methylation may play an important role in malignant transformation and senescence by predisposing critical growth regulatory genes to stochastic depression. Although most attention has been focused on oncogenes, growth suppressing genes could likewise be activated. The chapter set outs the hypothesis that interspersed repetitive sequences may play a role in mediating cellular senescence. Mechanisms by which SINEs might cause growth suppression have been outlined and the potential regulatory events leading to stochastic activation of these elements proposed.
