Anti-sense oligonucleotide of p21(waf1/cip1) prevents interleukin 4-mediated elevation of p27(kip1) in low grade astrocytoma cells.
Elevation of the cyclin-dependent kinase (cdk) inhibitor, p27(kip1) is necessary for Interleukin (IL)-4-mediated growth arrest of human low grade astrocytoma (RTLGA) cells and occurs at 24 h of treatment. Pathways involved in IL4 alteration of p27(kip1) are unknown, however. Here we investigated whether other cdk inhibitors contributed to the actions of IL-4 on RTLGA cells. By 12 h of IL-4 treatment, both cdk4 and cdk2 kinase activities against the retinoblastoma protein (pRb) were reduced and nuclear entry of pRb was prohibited. Twelve-hour cdk complexes contained elevated p21(waf1/cip1) but not p27(kip1), p15(ink4B) or p16(ink4A). IL-4 increased p21(waf1/cip1) but not p27(kip1) mRNA levels, and stimulated luciferase activity of a p21(waf1/cip1) promoter-luciferase reporter. In p53-mutant WITG3 cells, IL-4 did not alter p21(waf1/cip1) mRNA and promoter-luciferase activity or p27(kipl) protein, suggesting a need for functional p53. STAT6 phosphorylation by IL-4, however, occurred in both p53-mutant WITG3 and p53-functional RTLGA cells. Pre-treatment of RTLGA with anti-sense but not missense p21(waf1/cip1) oligonucleotide prior to IL-4: (a) restored cdk activities; (b) reduced cdk4-associated p21(waf1/cip1) levels; (c) prevented p27(kipl) elevation; and (d) reversed growth arrest. These results are the first to suggest that p21(waf1/cip1) is essential for IL-4-mediated elevation of p27(kip) and growth arrest of astrocytoma cells.
Liu
J
J
Rammelkamp Center for Education and Research, MetroHealth Medical Center, Cleveland, Ohio 44109, USA.
Estes
M L
ML
Drazba
J A
JA
Liu
H
H
Prayson
R
R
Kondo
S
S
Jacobs
B S
BS
Barnett
G H
GH
Barna
B P
BP
D001254:Astrocytoma / Q000235:genetics / Q000378:metabolism*; D018797:Cell Cycle Proteins; D050759:Cyclin-Dependent Kinase Inhibitor p21; D050760:Cyclin-Dependent Kinase Inhibitor p27; D018844:Cyclin-Dependent Kinases / Q000037:antagonists & inhibitors / Q000235:genetics / Q000378:metabolism; D016213:Cyclins / Q000235:genetics*; D006801:Humans; D015847:Interleukin-4 / Q000037:antagonists & inhibitors* / Q000502:physiology*; D008869:Microtubule-Associated Proteins / Q000037:antagonists & inhibitors* / Q000378:metabolism*; D009154:Mutation / Q000235:genetics; D020125:Mutation, Missense; D016376:Oligonucleotides, Antisense / Q000235:genetics / Q000494:pharmacology*; D012333:RNA, Messenger / Q000032:analysis; D016160:Retinoblastoma Protein / Q000037:antagonists & inhibitors / Q000378:metabolism; D014407:Tumor Cells, Cultured; D016159:Tumor Suppressor Protein p53 / Q000172:deficiency / Q000235:genetics; D025521:Tumor Suppressor Proteins
C493956:CDKN1A protein, human; D018797:Cell Cycle Proteins; D050759:Cyclin-Dependent Kinase Inhibitor p21; D016213:Cyclins; D008869:Microtubule-Associated Proteins; D016376:Oligonucleotides, Antisense; D012333:RNA, Messenger; D016160:Retinoblastoma Protein; D016159:Tumor Suppressor Protein p53; D025521:Tumor Suppressor Proteins; D050760:Cyclin-Dependent Kinase Inhibitor p27; D015847:Interleukin-4; D018844:Cyclin-Dependent Kinases