IMMEDIATE X-RAY-INDUCIBLE RESPONSES FROM MAMMALIAN-CELLS

It has been nearly 6 years since we reported the induction of new proteins in human normal and tumor cells after ionizing radiation. Since that time there has been an explosion of new data and ideas from a number of laboratories regarding the immediate responses of human cells to ionizing radiation. The data are, however, extremely difficult to interpret since researchers are using confluence-arrested, log-phase, normal or tumor cells, and are exposing these to a variety of doses of ionizing radiation. It is especially difficult to interpret data from cells that are exposed to supralethal doses of ionizing radiation. Thus this session of the workshop entitled ''Molecular, Genetic, and Cellular Basis of Radioresistance at Low Doses: A Case Of Inducible Repair?'' concentrated on inducible responses (both late and immediate) of human cells exposed to physiological doses of ionizing radiation. A major focus of future research in this field must be directed toward the function(s) of these inducible proteins and the expression of genes in DNA repair, cell cycle progression (especially radiation-induced cell progression delays) and/or cell death, including apoptosis.