title: Pyranocoumarins isolated from Peucedanum praeruptorum as differentiation inducers in human leukemic HL-60 cells.
abstract: Differentiation therapy for myeloid leukemia offers great potential as a supplement to the current treatment modalities. In the present report, we investigated if the pyranocoumarins, (+/-)-4'- O-acetyl-3'- O-angeloyl- cis-khellactone (or angular pyranocoumarin, APC) isolated from the medicinal plant Peucedanum praeruptorum Dunn, could induce human acute myeloid leukemic HL-60 cells to differentiate and elucidated the molecular mechanism(s) involved. The ability of HL-60 cells to reduce nitroblue tetrazolium (NBT) was significantly increased after APC treatment for 72 h. In these differentiating HL-60 cells, cell surface differentiation markers CD11b (for myeloid cells) and CD14 (for monocytic cells) were detected in 90.3 % and 70.1 % of the cells, respectively. The differentiation inducing effect of APC was time- and dose-dependent. Treatment with 20 microg/mL APC for 72 h inhibited cell growth by 90 % and cell cycle analysis revealed an increase in the proportion of G1 phase cells. In these growth-inhibited cells the expression of the cyclin-dependent kinase inhibitor p27 kip1, but not p21 WAF1, was up-regulated as shown by Western blotting. Differentiation inducing signal pathways were investigated and it was shown that phospho-MEK and phospho-ERK were elevated shortly after the addition of APC. Pre-incubation of the cells with MEK1 inhibitor PD98059 blocked this APC-induced differentiation. Our results suggest that APC are potent inducers of HL-60 cell differentiation along both the myelocytic and monocytic lineages and are potential agents for differentiation-treatment of leukemia.
authors.affiliation: Bioactive Products Research Group, City University of Hong Kong, Kowloon, Hong Kong SAR, China.
authors.forename: Jin-Xia
authors.initials: JX
authors.lastname: Zhang
authors.forename: Wang-Fun
authors.initials: WF
authors.lastname: Fong
authors.forename: Jimmy Yiu-Cheong
authors.initials: JY
authors.lastname: Wu
authors.forename: Mengsu
authors.initials: M
authors.lastname: Yang
authors.forename: Hon-Yeung
authors.initials: HY
authors.lastname: Cheung
mesh_terms: D000972:Antineoplastic Agents, Phytogenic / Q000008:administration & dosage / Q000494:pharmacology*; D019661:Apiaceae; D015153:Blotting, Western; D002453:Cell Cycle / Q000187:drug effects; D018797:Cell Cycle Proteins / Q000378:metabolism; D002454:Cell Differentiation / Q000187:drug effects*; D050760:Cyclin-Dependent Kinase Inhibitor p27; D004305:Dose-Response Relationship, Drug; D005434:Flow Cytometry; D015973:Gene Expression Regulation, Leukemic; D018922:HL-60 Cells / Q000187:drug effects; D006801:Humans; D007951:Leukemia, Myeloid / Q000188:drug therapy / Q000473:pathology; D008517:Phytotherapy; D028321:Plant Preparations / Q000008:administration & dosage / Q000494:pharmacology*; D039681:Pyranocoumarins / Q000008:administration & dosage / Q000494:pharmacology*; D025521:Tumor Suppressor Proteins / Q000378:metabolism
chemical_list: D000972:Antineoplastic Agents, Phytogenic; D018797:Cell Cycle Proteins; D028321:Plant Preparations; D039681:Pyranocoumarins; D025521:Tumor Suppressor Proteins; D050760:Cyclin-Dependent Kinase Inhibitor p27