Effect of quercetin on activities of protein kinase C and tyrosine protein kinase from HL-60 cells
Abstract
AIM: To study the effect of quercetin (Que) on the activities of cytosol and
membrane protein kinase C (PKC) and tyrosine protein kinase (TPK) from HL-60
cells in vitro.
METHODS: The number of viable cells was counted by a trypan blue dye exclusion
test. PKC activity was assayed by incubating PKC with histone III S and
[gamma-32P]ATP. TPK activity was assayed by incubating TPK with poly
glutamate.tyrosine (4:1).
RESULTS: Que inhibited the proliferation of HL-60 cells in a
concentration-dependent manner, its IC50 was 29 (22-37) mumol.L-1 after 48-h
treatment; Que strongly inhibited the activity of cytosol PKC and membrane TPK
with IC50 31 (20-48) mumol.L-1, 24 (13-45) mumol.L-1, respectively, but did not
affect membrane PKC and cytosol TPK from HL-60 cells in vitro.
CONCLUSION: The inhibitory effect of Que on the growth of tumor cells is related
to its inhibitory effects on PKC and/or TPK.
Keywords:
membrane protein kinase C (PKC) and tyrosine protein kinase (TPK) from HL-60
cells in vitro.
METHODS: The number of viable cells was counted by a trypan blue dye exclusion
test. PKC activity was assayed by incubating PKC with histone III S and
[gamma-32P]ATP. TPK activity was assayed by incubating TPK with poly
glutamate.tyrosine (4:1).
RESULTS: Que inhibited the proliferation of HL-60 cells in a
concentration-dependent manner, its IC50 was 29 (22-37) mumol.L-1 after 48-h
treatment; Que strongly inhibited the activity of cytosol PKC and membrane TPK
with IC50 31 (20-48) mumol.L-1, 24 (13-45) mumol.L-1, respectively, but did not
affect membrane PKC and cytosol TPK from HL-60 cells in vitro.
CONCLUSION: The inhibitory effect of Que on the growth of tumor cells is related
to its inhibitory effects on PKC and/or TPK.