title: Oroxylin A, a natural anticancer flavonoid compound, induces differentiation of t(8;21)-positive Kasumi-1 and primary acute myeloid leukemia cells.
abstract: OBJECTIVE
  AML1/ETO fusion gene is one of disease-causing genes of t(8;21)-positive acute myeloid leukemia (AML). Oroxylin A (OA) has showed anticancer effects on other cancer cells. Here, studies were conducted to determine the antileukemia effect of OA on t(8;21)-positive AML cells in vitro and in vivo.
  
  
  METHODS
  The effects of OA on cell viability of t(8;21)-positive Kasumi-1 and primary AML cells were analyzed by MTT assay. Cell differentiation was examined by NBT reduction assay, flow cytometry analysis for CD11b/CD14, and Giemsa stain. Protein expressions were determined by Western blots. Immunofluorescence assay was used to verify the effect of OA on HDAC-1 expression in vivo. Immunohistochemical staining was applied to evaluate leukemic infiltration of AML-bearing NOD/SCID mice.
  
  
  RESULTS
  OA enhanced NBT reduction activity and CD11b/CD14 expression of AML1/ETO-positive AML cells markedly. Results of Giemsa staining also demonstrated that OA could induce the morphologic changes with reduction of nuclear/cytoplasmic ratios, suggesting the cell differentiation induced by OA. Further study showed that OA decreased the expression of fusion protein AML1/ETO and down-regulated HDAC-1 protein levels in vitro and in vivo. Moreover, OA increased the expression of differentiation-related proteins C/EBPα and P21. Acetylation levels of histones were also advanced obviously after treatment of OA. In vivo study indicated that OA could prolong the survival of AML-bearing NOD/SCID mice and reduce leukocytic infiltration of the spleen.
  
  
  CONCLUSIONS
  All these results suggested that OA might be a novel candidate agent for differentiation therapy for AML1/ETO-positive AML and the mechanism required further investigation.
authors.affiliation: State Key Laboratory of Natural Medicines, Jiangsu Key Laboratory of Carcinogenesis and Intervention, Key Laboratory of Drug Quality Control and Pharmacovigilance, Ministry of Education, JiangSu Key Laboratory of Drug Design and Optimization, China Pharmaceutical University, 24 Tongjiaxiang, Nanjing, 210009, People's Republic of China.
authors.forename: Hui
authors.initials: H
authors.lastname: Hui
authors.affiliation: State Key Laboratory of Natural Medicines, Jiangsu Key Laboratory of Carcinogenesis and Intervention, Key Laboratory of Drug Quality Control and Pharmacovigilance, Ministry of Education, JiangSu Key Laboratory of Drug Design and Optimization, China Pharmaceutical University, 24 Tongjiaxiang, Nanjing, 210009, People's Republic of China.
authors.forename: Xiaoxiao
authors.initials: X
authors.lastname: Zhang
authors.affiliation: State Key Laboratory of Natural Medicines, Jiangsu Key Laboratory of Carcinogenesis and Intervention, Key Laboratory of Drug Quality Control and Pharmacovigilance, Ministry of Education, JiangSu Key Laboratory of Drug Design and Optimization, China Pharmaceutical University, 24 Tongjiaxiang, Nanjing, 210009, People's Republic of China.
authors.forename: Hui
authors.initials: H
authors.lastname: Li
authors.affiliation: State Key Laboratory of Natural Medicines, Jiangsu Key Laboratory of Carcinogenesis and Intervention, Key Laboratory of Drug Quality Control and Pharmacovigilance, Ministry of Education, JiangSu Key Laboratory of Drug Design and Optimization, China Pharmaceutical University, 24 Tongjiaxiang, Nanjing, 210009, People's Republic of China.
authors.forename: Xiao
authors.initials: X
authors.lastname: Liu
authors.affiliation: State Key Laboratory of Natural Medicines, Jiangsu Key Laboratory of Carcinogenesis and Intervention, Key Laboratory of Drug Quality Control and Pharmacovigilance, Ministry of Education, JiangSu Key Laboratory of Drug Design and Optimization, China Pharmaceutical University, 24 Tongjiaxiang, Nanjing, 210009, People's Republic of China.
authors.forename: Le
authors.initials: L
authors.lastname: Shen
authors.affiliation: Department of Hematology, The First Affiliated Hospital of Nanjing Medical University, Jiangsu Province Hospital, Nanjing, Jiangsu Province, People's Republic of China.
authors.forename: Yu
authors.initials: Y
authors.lastname: Zhu
authors.affiliation: Department of Hematology, The Affiliated Drum Tower Hospital of Nanjing University Medical School, Nanjing, 210008, People's Republic of China. xjy1967@sina.com.
authors.forename: Jingyan
authors.initials: J
authors.lastname: Xu
authors.affiliation: State Key Laboratory of Natural Medicines, Jiangsu Key Laboratory of Carcinogenesis and Intervention, Key Laboratory of Drug Quality Control and Pharmacovigilance, Ministry of Education, JiangSu Key Laboratory of Drug Design and Optimization, China Pharmaceutical University, 24 Tongjiaxiang, Nanjing, 210009, People's Republic of China. anticancer_drug@163.com.
authors.forename: Qinglong
authors.initials: Q
authors.lastname: Guo
authors.affiliation: State Key Laboratory of Natural Medicines, Jiangsu Key Laboratory of Carcinogenesis and Intervention, Key Laboratory of Drug Quality Control and Pharmacovigilance, Ministry of Education, JiangSu Key Laboratory of Drug Design and Optimization, China Pharmaceutical University, 24 Tongjiaxiang, Nanjing, 210009, People's Republic of China. luna555@163.com.
authors.forename: Na
authors.initials: N
authors.lastname: Lu
mesh_terms: D000818:Animals; D000970:Antineoplastic Agents / Q000494:pharmacology*; D002454:Cell Differentiation / Q000187:drug effects*; D002881:Chromosomes, Human, Pair 12; D002898:Chromosomes, Human, Pair 8; D050676:Core Binding Factor Alpha 2 Subunit / Q000378:metabolism; D005419:Flavonoids / Q000494:pharmacology*; D056284:Histone Deacetylase 1 / Q000378:metabolism; D006801:Humans; D015470:Leukemia, Myeloid, Acute / Q000235:genetics / Q000473:pathology*; D051379:Mice; D016688:Mice, Inbred NOD; D016513:Mice, SCID; D011518:Proto-Oncogene Proteins / Q000378:metabolism; D000075142:RUNX1 Translocation Partner 1 Protein; D014157:Transcription Factors / Q000378:metabolism; D014178:Translocation, Genetic
chemical_list: D000970:Antineoplastic Agents; D050676:Core Binding Factor Alpha 2 Subunit; D005419:Flavonoids; D011518:Proto-Oncogene Proteins; D000075142:RUNX1 Translocation Partner 1 Protein; C493728:RUNX1 protein, human; C082222:RUNX1T1 protein, human; D014157:Transcription Factors; C080669:5,7-dihydroxy-6-methoxy-2-phenylchromen-4-one; D056284:Histone Deacetylase 1
keywords: AML; AML1/ETO; Differentiation; HDAC-1