Dear netters. As far as I've understood, normal tissue cells divide a
determined number of times (64 or so) and then they die. Cancer cells
and neoplastic cell-lines seem to have lost this "limitation of number of
divisions" and could in theory divide indefinitely. So how do normal
cells count the number of divisions they have been through ? Do they
accumulate a "count-protein" that increases in amount/cell with
increasing division-passage, modify some other (more or less) vital part
of the cells machinery (allow DNA to be mutated, allow oxidation, allow
free radicals ...) slowly as they grow older or is there some other
mechanism. What is known about cells "counting" today ? And might that
"counting-meter" be reset to zero or at least be halted ?
Sincerely,
Jan
E-mail thorup at biobase.dk
