The benzophenanthridine alkaloid fagaronine induces erythroleukemic cell differentiation by gene activation.
Fagaronine, a benzophenanthridine alkaloid from Fagara zanthoxyloides Lam. (Rutaceae), has been tested on the erythroleukemic cell line K562 in order to explain some previous results on cell differentiation. In this study we showed that fagaronine induces a significant hemoglobinization of the human erythroleukemic cell line K562. This hemoglobin synthesis was accompanied by a strong increase of erythroid mRNA expression such as gamma- and alpha-globin, and PBGD, an enzyme of heme synthesis. In addition, the Epo-R transcripts were also stimulated indicating that cells are engaged in a maturation process. Both transcription factors GATA-1 and NF-E2, which play an important role in the regulation of genes involved in the erythroid differentiation, were also transcriptionally up-regulated. To elucidate the possible role of GATA-1 in the FAG-induced differentiation of K562 cells, we transfected reporter constructs containing regulatory regions of erythroid genes encompassing GATA-1 binding sites. After 48 hours of treatment, FAG stimulated the EPO-R and gamma-globin promoters by 2- to 3-fold and the promoter/enhancer region of GATA-1 gene by 3.2-fold. A mutation within the GATA-1 binding sites strongly decreased the promoter activation induced by FAG. Taken together, our results represent a demonstration that FAG exerts its differentiating activity by a specific activation of the regulating GATA-1 regions of genes involved in the erythroid phenotype expression.
Dupont
Claude
C
JE 2428 Onco-Pharmacologie, UFR Pharmacie, IFR 53 Biomolécules, Université de Reims Champagne-Ardenne, Reims, France.
Couillerot
Eric
E
Gillet
Reynald
R
Caron
Catherine
C
Zeches-Hanrot
Monique
M
Riou
Jean-François
JF
Trentesaux
Chantal
C
D000470:Alkaloids / Q000494:pharmacology*; D000972:Antineoplastic Agents, Phytogenic / Q000494:pharmacology*; D053119:Benzophenanthridines; D002454:Cell Differentiation / Q000187:drug effects; D017931:DNA Primers; D004268:DNA-Binding Proteins / Q000235:genetics; D050981:Erythroid-Specific DNA-Binding Factors; D004920:Erythropoiesis / Q000187:drug effects; D050982:GATA1 Transcription Factor; D015870:Gene Expression; D006801:Humans; D020014:K562 Cells / Q000187:drug effects; D050983:NF-E2 Transcription Factor; D050984:NF-E2 Transcription Factor, p45 Subunit; D010617:Phenanthridines / Q000494:pharmacology*; D008517:Phytotherapy; D018517:Plant Roots; D012333:RNA, Messenger / Q000032:analysis; D020133:Reverse Transcriptase Polymerase Chain Reaction; D014157:Transcription Factors / Q000235:genetics; D032106:Zanthoxylum
D000470:Alkaloids; D000972:Antineoplastic Agents, Phytogenic; D053119:Benzophenanthridines; D017931:DNA Primers; D004268:DNA-Binding Proteins; D050981:Erythroid-Specific DNA-Binding Factors; D050982:GATA1 Transcription Factor; C494688:GATA1 protein, human; D050983:NF-E2 Transcription Factor; D050984:NF-E2 Transcription Factor, p45 Subunit; C494692:NFE2 protein, human; D010617:Phenanthridines; D012333:RNA, Messenger; D014157:Transcription Factors; C002066:fagaronine