Fluctuation of trypsin-like proteinase activity in the cell cycle of synchronized and growing HeLa cells, and the effect of GMCHA-OPhBut.
HeLa cells synchronized by double-thymidine block were grown in Eagle's minimum essential medium supplemented with 10% calf serum, and the fluctuation of trypsin-like protease activity in the cell cycle was examined. Seven distinct activity peaks were observed in one cell cycle at a cell density of 2%: two peaks in S phase, one peak at the S/G2 boundary, one peak in early M phase and one at the M/G1 boundary, and two peaks in G1 phase. HeLa cells synchronized by a mitotic detachment technique also showed similar results at cell density of 4.8%. The appearance of trypsin-like proteinase activity in the cell cycle was markedly affected by cell density, and no definite peak was observed above 8%. trans-Guanidinomethylcyclohexanecarboxylic and 4-tert-butylphenyl ester (GMCHA-OPhBut), a specific inhibitor for trypsin and a strong inhibitor of HeLa cell growth, had no effect on the various events in the first S, G2 and M phases, such as the incorporation of [methyl-3H]thymidine into DNA, the increase in the cell concentration, and the appearance of trypsin-like proteinase activity, whereas it retarded the onset of the second S phase and the various events in the second S, G2 and M phases for 3 h. In particular, it induced the appearance of a new proteinase peak at the G1/S boundary.
Kozaki
Y
Y
Faculty of Pharmacy, Tokushima Bunri University, Japan.
Amoh
T
T
Yamaguchi
N
N
Muramatu
M
M
D002452:Cell Count; D002453:Cell Cycle / Q000187:drug effects / Q000502:physiology*; D003509:Cyclohexanecarboxylic Acids / Q000494:pharmacology*; D006367:HeLa Cells; D006801:Humans; D007399:Interphase / Q000187:drug effects; D013936:Thymidine / Q000494:pharmacology; D014357:Trypsin / Q000378:metabolism*; D014361:Trypsin Inhibitors / Q000494:pharmacology*
D003509:Cyclohexanecarboxylic Acids; D014361:Trypsin Inhibitors; C038303:NCO 650; D014357:Trypsin; D013936:Thymidine