title: Epigenetic inactivation of DLX4 is associated with disease progression in chronic myeloid leukemia.
abstract: Aberrant DNA methylation of various genes has been identified to be associated with disease progression in chronic myeloid leukemia (CML). Our study was intended to investigate DLX4 methylation pattern in different clinical stages of CML and further determine its role in regulating DLX4 expression. Real-time quantitative methylation-specific PCR and bisulfite sequencing PCR were applied to detect DLX4 methylation. 5-aza-2'-deoxycytidine (5-aza-dC) was used for demethylation studies. DLX4 was significantly hypermethylated in CML patients (P = 0.002) especially in blastic phase (BC) stage (P < 0.001) as compared with controls. Moreover, DLX4 methylation level in BC stage was significantly higher than in chronic phase (CP) stage (P < 0.001). DLX4 methylation density was significantly increased during the progression of CML among the tested two patients (P < 0.001). DLX4 hypermethylation occurred with the highest incidence in BC stage (83%), lower incidence in acute phase (AP) stage (43%), and the lowest incidence in CP stage (26%) (P = 0.001). Moreover, t(9; 22) with additional alteration cases had significantly higher frequency of DLX4 hypermethylation compared with the other cytogenetics (P = 0.010). Significantly negative correlation was observed between DLX4 methylation and DLX4-TV2 (the shorter DLX4 isoform) expression (R = -0.382, P = 0.001, n = 78) but not between DLX4 methylation and BP1 (the longer DLX4 isoform) expression (R = 0.134, P = 0.244, n = 78) in CML patients. Both DLX4-TV2 and BP1 mRNA were significantly increased after 5-aza-dC treatment in K562 cell line (P < 0.001). Our study indicated that hypermethylation of DLX4 correlated with disease progression of CML. Moreover, DLX4 expression was regulated by its methylation in CML.
authors.affiliation: Department of Hematology, Affiliated People's Hospital of Jiangsu University, Zhenjiang, Jiangsu, PR China.
authors.forename: Jing-Dong
authors.initials: JD
authors.lastname: Zhou
authors.affiliation: Department of Hematology, Affiliated People's Hospital of Jiangsu University, Zhenjiang, Jiangsu, PR China.
authors.forename: Yu-Xin
authors.initials: YX
authors.lastname: Wang
authors.affiliation: Department of Hematology, Affiliated People's Hospital of Jiangsu University, Zhenjiang, Jiangsu, PR China.
authors.forename: Ting-Juan
authors.initials: TJ
authors.lastname: Zhang
authors.affiliation: Department of Hematology, Affiliated People's Hospital of Jiangsu University, Zhenjiang, Jiangsu, PR China.
authors.forename: Dong-qin
authors.initials: DQ
authors.lastname: Yang
authors.affiliation: Laboratory Center, Affiliated People's Hospital of Jiangsu University, Zhenjiang, Jiangsu, PR China.
authors.forename: Dong-Ming
authors.initials: DM
authors.lastname: Yao
authors.affiliation: Laboratory Center, Affiliated People's Hospital of Jiangsu University, Zhenjiang, Jiangsu, PR China.
authors.forename: Hong
authors.initials: H
authors.lastname: Guo
authors.affiliation: Department of Hematology, Affiliated People's Hospital of Jiangsu University, Zhenjiang, Jiangsu, PR China.
authors.forename: Lei
authors.initials: L
authors.lastname: Yang
authors.affiliation: Laboratory Center, Affiliated People's Hospital of Jiangsu University, Zhenjiang, Jiangsu, PR China.
authors.forename: Ji-Chun
authors.initials: JC
authors.lastname: Ma
authors.affiliation: Laboratory Center, Affiliated People's Hospital of Jiangsu University, Zhenjiang, Jiangsu, PR China.
authors.forename: Xiang-Mei
authors.initials: XM
authors.lastname: Wen
authors.affiliation: Department of Hematology, Affiliated People's Hospital of Jiangsu University, Zhenjiang, Jiangsu, PR China.
authors.forename: Jing
authors.initials: J
authors.lastname: Yang
authors.affiliation: Laboratory Center, Affiliated People's Hospital of Jiangsu University, Zhenjiang, Jiangsu, PR China. Electronic address: linjiangmail@sina.com.
authors.forename: Jiang
authors.initials: J
authors.lastname: Lin
authors.affiliation: Department of Hematology, Affiliated People's Hospital of Jiangsu University, Zhenjiang, Jiangsu, PR China. Electronic address: qianjun0007@hotmail.com.
authors.forename: Jun
authors.initials: J
authors.lastname: Qian
mesh_terms: D000328:Adult; D000368:Aged; D018450:Disease Progression; D044127:Epigenesis, Genetic; D005260:Female; D018398:Homeodomain Proteins / Q000235:genetics*; D006801:Humans; D015464:Leukemia, Myelogenous, Chronic, BCR-ABL Positive / Q000235:genetics* / Q000473:pathology; D008297:Male; D008875:Middle Aged; D014157:Transcription Factors / Q000235:genetics*; D055815:Young Adult
chemical_list: C105304:DLX4 protein, human; D018398:Homeodomain Proteins; D014157:Transcription Factors
keywords: CML; DLX4; Disease progression; Hypermethylation; Regulation