(word processor parameters LM=8, RM=78, TM=2, BM=2) Taken from KeelyNet BBS (214) 324-3501 Sponsored by Vangard Sciences PO BOX 1031 Mesquite, TX 75150 October 6, 1990 listed on KeelyNet as AGE2.ASC -------------------------------------------------------------------- JOURNAL WATCH Copyright 1988 Massachusetts Medical Society. All rights reserved. Electronically reproduced at DR B'S BBS by permission from the publisher. Journal Watch, a medical literature news service, uses physician- editors to track important new clinical studies published in a core group of 20 journals. New stories are added twice a week. For subscription information to the print version of Journal Watch, call 1-800-843-6356. Journal Watch surveys a broad range of biomedical literature; it is not intended to substitute for reading the original publications. You should exercise individual judgment in using this information. -------------------------------------------------------------------- 9/25/90 7. UNRAVELING THE BIOLOGY OF CELLULAR AGING We grow old because our cells grow old -- a process we think of as inevitable and immutable. Cancer cells, however, seem to escape the process of aging and become "immortal." This review of recent research sheds some light on the cellular aging process and suggests a connection between the biology of cellular aging and the biology of cancer. Investigators have observed that a human diploid fibroblast placed in a cell culture goes through a limited, predictable number of replications before it stops dividing. Moreover, the replicative life span of an animal's fibroblasts has been shown to correlate with the life span of the species. When a fibroblast becomes senescent, its growth is stopped at a particular part of the cell cycle (the G1/S boundary) and it ceases to respond to certain growth factors. Page 1 Certain growth-inducing proto-oncogenes seem to be turned off, while concentrations of possibly growth-retarding proteins seem to be increased. Researchers speculate that cancer cells circumvent the mechanisms of senescence, and experiments have shown that specific molecular manipulations can cause a senescent cell to begin dividing again. It remains to be shown whether further understanding of cellular aging will have implications for the control of aging in plants and animals, but the prospect is exciting. -- ALK. Goldstein S. Replicative senescence: the human fibroblast comes of age. Science 1990 Sep 7; 249:1129-33 -------------------------------------------------------------------- If you have comments or other information relating to such topics as this paper covers, please upload to KeelyNet or send to the Vangard Sciences address as listed on the first page. Thank you for your consideration, interest and support. Jerry W. Decker.........Ron Barker...........Chuck Henderson Vangard Sciences/KeelyNet -------------------------------------------------------------------- If we can be of service, you may contact Jerry at (214) 324-8741 or Ron at (214) 242-9346 -------------------------------------------------------------------- Page 2