Radiation and other stress responses and their relevance to cancer: Some general features

Various physical and chemical agents, when brought into contact with mammalian cells at levels or doses which are sub-lethal, can induce a wide variety of biochemical changes. These 'stress responses' are usually transient in nature. They include the induction of resistance to higher doses of the same agent as well as other agents, increased rates of DNA replication, up-regulation of a variety of proteins including some involved in cell growth and proliferation. In this brief overview, some of the changes that are induced by stress agents are discussed. These include changes in cellular response and cellular properties, the expression of macromolecules at the sub-cellular level, and the regulation of protooncogene transcription. (author). 41 refs., 1 fig., 2 tabs