title: Epigallocatechin-3-gallate induces cell death in acute myeloid leukaemia cells and supports all-trans retinoic acid-induced neutrophil differentiation via death-associated protein kinase 2.
abstract: Acute promyelocytic leukaemia (APL) patients are successfully treated with all-trans retinoic acid (ATRA). However, concurrent chemotherapy is still necessary and less toxic therapeutic approaches are needed. Earlier studies suggested that in haematopoietic neoplasms, the green tea polyphenol epigallocatechin-3-gallate (EGCG) induces cell death without adversely affecting healthy cells. We aimed at deciphering the molecular mechanism of EGCG-induced cell death in acute myeloid leukaemia (AML). A significant increase of death-associated protein kinase 2 (DAPK2) levels was found in AML cells upon EGCG treatment paralleled by increased cell death that was significantly reduced upon silencing of DAPK2. Moreover, combined ATRA and EGCG treatment resulted in cooperative DAPK2 induction and potentiated differentiation. EGCG toxicity of primary AML blasts correlated with 67 kDa laminin receptor (67LR) expression. Pretreatment of AML cells with ATRA, causing downregulation of 67LR, rendered these cells resistant to EGCG-mediated cell death. In summary, it was found that (i) DAPK2 is essential for EGCG-induced cell death in AML cells, (ii) ATRA and EGCG cotreatment significantly boosted neutrophil differentiation, and 67LR expression correlates with susceptibility of AML cells to EGCG. We thus suggest that EGCG, by selectively targeting leukaemic cells, may improve differentiation therapies for APL and chemotherapy for other AML subtypes.
authors.affiliation: Department of Clinical Research, Experimental Oncology/Haematology, Bern University Hospital, Switzerland.
authors.forename: Adrian
authors.initials: A
authors.lastname: Britschgi
authors.forename: Hans-Uwe
authors.initials: HU
authors.lastname: Simon
authors.forename: Andreas
authors.initials: A
authors.lastname: Tobler
authors.forename: Martin F
authors.initials: MF
authors.lastname: Fey
authors.forename: Mario P
authors.initials: MP
authors.lastname: Tschan
mesh_terms: D000970:Antineoplastic Agents / Q000494:pharmacology*; D000971:Antineoplastic Combined Chemotherapy Protocols / Q000494:pharmacology; D051017:Apoptosis Regulatory Proteins / Q000502:physiology; D017871:Calcium-Calmodulin-Dependent Protein Kinases / Q000502:physiology; D002392:Catechin / Q000031:analogs & derivatives* / Q000494:pharmacology; D016923:Cell Death / Q000187:drug effects; D002454:Cell Differentiation / Q000187:drug effects; D064550:Death-Associated Protein Kinases; D004305:Dose-Response Relationship, Drug; D004353:Drug Evaluation, Preclinical / Q000379:methods; D055785:Gene Knockdown Techniques; D006801:Humans; D015470:Leukemia, Myeloid, Acute / Q000473:pathology*; D009504:Neutrophils / Q000187:drug effects*; D020133:Reverse Transcriptase Polymerase Chain Reaction / Q000379:methods; D014212:Tretinoin / Q000494:pharmacology*; D014407:Tumor Cells, Cultured; D015854:Up-Regulation / Q000187:drug effects
chemical_list: D000970:Antineoplastic Agents; D051017:Apoptosis Regulatory Proteins; D014212:Tretinoin; D002392:Catechin; C045651:epigallocatechin gallate; C579104:DAPK2 protein, human; D064550:Death-Associated Protein Kinases; D017871:Calcium-Calmodulin-Dependent Protein Kinases