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A possible involvement of polyamines in the initiation of DNA synthesis by human WI-38 and mouse BALB/3T3 cells

✍ Scribed by A. L. Boynton; J. F. Whitfield; R. J. Isaacs

Publisher
John Wiley and Sons
Year
1976
Tongue
English
Weight
605 KB
Volume
89
Category
Article
ISSN
0021-9541

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✦ Synopsis

Abstract

Changing the medium, or adding fresh serum, induces a large proportion of the proliferatively quiescent cells in confluent monolayers of human WI‐38 and mouse BALB/3T3 cells to initiate a growth‐division cycle. Exposure at the time of the medium change or serum addition to MGBG (methyl glyoxal bis [guanylhydrazone]), an inhibitor of spermidine and spermine synthesis and function, reduces or stops the subsequent flow of cells into the DNA‐synthetic phase, without grossly affecting RNA synthesis. Mediation of MGBG action by an actual or functional shortage of spermidine or spermine (but not putrescine), and consequently an involvement of these polyamines in DNA synthesis, is strongly suggested by the reduction of the inhibitor's effectiveness by a brief (1‐hour), early prereplicative exposure of the treated cells to exogenous spermidine and spermine (but not putrescine).

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