Saucernetin-7 isolated from Saururus chinensis inhibits proliferation of human promyelocytic HL-60 leukemia cells via G0/G1 phase arrest and induction of differentiation.
In the present study, we investigated the in vitro effect of saucernetin-7, which is a dineolignan isolated from Saururus chinensis, on the proliferation, cell cycle-regulation and differentiation of HL-60 human promyelocytic leukemia cells. Saucernetin-7 potently inhibited the proliferation of HL-60 cells in both a dose- and time-dependent manner with an IC50, approximately 5 microM. DNA flow-cytometry indicated that saucernetin-7 markedly induced a G1 phase arrest of HL-60 cells. Among the G1 phase cell cycle-related proteins, the levels of cyclin-dependent kinase (CDK)6 and cyclin D1 were reduced by saucernetin-7, whereas the steady-state levels of CDK2, CDK4, cyclin D2, cyclin D3 and cyclin E were unaffected. The protein and mRNA levels of a CDK inhibitor p21CIP1/WAF1, but not p27KIP1, were markedly increased by saucernetin-7 and p21CIP1/WAF1 induction is likely to occur at the transcriptional level because actinomycin D blocked this induction. In addition, saucernetin-7 markedly enhanced the binding of p21CIP1/WAF1 with CDK2 and CDK6, resulting in the reduced activity of both kinases and the hypophosphorylation of Rb protein. We furthermore suggest that saucernetin-7 is a potent inducer of the differentiation of HL-60 cells, based on observations such as a reduction of the nitroblue tetrazolium level, an increase in the esterase activities and phagocytic activity, morphology changes, and the expression of CD14 and CD66b surface antigens. In conclusion, the onset of saucernetin-7-induced the G0/G1 arrest of HL-60 cells prior to the differentiation is linked to a sharp up-regulation of the p21CIP1/WAF1 level and a decrease in the CDK2 and CDK6 activities. This is the first report demonstrating that saucernetin-7 potently inhibits the proliferation of human promyelocytic HL-60 cells via the G1 phase cell cycle arrest and differentiation induction.
Seo
Bo-Rim
BR
College of Pharmacy, Kyung-Hee University, Hoegi-Dong, Seoul 130-701, Korea.
Lee
Kyung-Won
KW
Ha
Joohun
J
Park
Hee-Jun
HJ
Choi
Jong-Won
JW
Lee
Kyung-Tae
KT
D000818:Animals; D015703:Antigens, CD; D000951:Antigens, Neoplasm / Q000096:biosynthesis; D015153:Blotting, Western; D042846:CDC2-CDC28 Kinases / Q000378:metabolism; D015815:Cell Adhesion Molecules / Q000096:biosynthesis; D002453:Cell Cycle; D002454:Cell Differentiation; D002455:Cell Division; D045744:Cell Line, Tumor; D051357:Cyclin-Dependent Kinase 2; D051361:Cyclin-Dependent Kinase 6; D050759:Cyclin-Dependent Kinase Inhibitor p21; D018844:Cyclin-Dependent Kinases / Q000378:metabolism; D016213:Cyclins / Q000378:metabolism; D004247:DNA / Q000378:metabolism; D004305:Dose-Response Relationship, Drug; D004591:Electrophoresis, Polyacrylamide Gel; D005434:Flow Cytometry; D005663:Furans / Q000378:metabolism*; D016193:G1 Phase; D058851:GPI-Linked Proteins; D005982:Glutathione Transferase / Q000378:metabolism; D018922:HL-60 Cells; D006801:Humans; D020128:Inhibitory Concentration 50; D017705:Lignans; D018950:Lipopolysaccharide Receptors / Q000096:biosynthesis; D051379:Mice; D008956:Models, Chemical; D010587:Phagocytosis; D010766:Phosphorylation; D010936:Plant Extracts / Q000378:metabolism* / Q000627:therapeutic use*; D011233:Precipitin Tests; D016192:Resting Phase, Cell Cycle; D016160:Retinoblastoma Protein / Q000378:metabolism; D020133:Reverse Transcriptase Polymerase Chain Reaction; D032134:Saururaceae / Q000378:metabolism*; D013778:Tetrazolium Salts / Q000494:pharmacology; D013844:Thiazoles / Q000494:pharmacology; D013997:Time Factors; D014158:Transcription, Genetic
D015703:Antigens, CD; D000951:Antigens, Neoplasm; C493956:CDKN1A protein, human; C504120:CEACAM8 protein, human; C493957:Cdkn1a protein, mouse; D015815:Cell Adhesion Molecules; D050759:Cyclin-Dependent Kinase Inhibitor p21; D016213:Cyclins; D005663:Furans; D058851:GPI-Linked Proteins; D017705:Lignans; D018950:Lipopolysaccharide Receptors; D010936:Plant Extracts; D016160:Retinoblastoma Protein; D013778:Tetrazolium Salts; D013844:Thiazoles; C481154:saucernetin-7; D004247:DNA; D005982:Glutathione Transferase; D042846:CDC2-CDC28 Kinases; C495894:CDK2 protein, human; C495911:CDK6 protein, human; C495893:Cdk2 protein, mouse; C495912:Cdk6 protein, mouse; D051357:Cyclin-Dependent Kinase 2; D051361:Cyclin-Dependent Kinase 6; D018844:Cyclin-Dependent Kinases; C022616:thiazolyl blue