title: The effects of increased expression of DLK1 gene on the pathogenesis of myelodysplastic syndromes.
abstract: To study the potential role of Delta-like-1 (DLK1) in myelodysplastic syndromes (MDS), we carried out a series of experiments and found that DLK1 mRNA levels are dysregulated in patients with MDS or acute myelogenous leukemia (AML), and its overexpression leads to dysfunction of 32D and 3T3 cells. We conclude that DLK1 dysfunction may contribute to abnormal hematopoiesis of MDS and may be 1 of the antioncogenes. Delta-like-1 (DLK1) is frequently expressed at elevated levels in CD34(+) cells from patients with MDS. To investigate its role in the pathogenesis of MDS, we tested bone marrow samples from a panel of patients with MDS, AML, or myeloproliferative neoplasms, with real-time polymerase chain reaction (PCR). We show here that DLK1 mRNA levels are higher in MDS patients and lower in AML patients than in healthy individuals. Myeloid progenitor 32D cells overexpressing DLK1 display increased apoptosis, reduced differentiation, and decreased cell number expansion, which is also accompanied by changes in cell cycle progression. Immortalized fibroblastic 3T3 cells can grow into tumors in nude mice but the size of tumors are smaller from those overexpressing DLK1. These observations suggest that DLK1 dysfunction may contribute to the ineffective hematopoiesis of MDS.
authors.affiliation: State Key Laboratory of Experimental Hematology, Chinese Academy of Medical Sciences and Peking Union Medical College, Tianjin, China.
authors.forename: Xiaotang
authors.initials: X
authors.lastname: Ma
authors.forename: Yue
authors.initials: Y
authors.lastname: Zhang
authors.forename: Lin
authors.initials: L
authors.lastname: Yang
authors.forename: Zefeng
authors.initials: Z
authors.lastname: Xu
authors.forename: Zhijian
authors.initials: Z
authors.lastname: Xiao
mesh_terms: D000818:Animals; D017209:Apoptosis / Q000502:physiology; D002135:Calcium-Binding Proteins; D002453:Cell Cycle; D002454:Cell Differentiation / Q000502:physiology; D048708:Cell Growth Processes / Q000502:physiology; D006801:Humans; D036341:Intercellular Signaling Peptides and Proteins / Q000096:biosynthesis* / Q000235:genetics / Q000378:metabolism; D008565:Membrane Proteins / Q000096:biosynthesis* / Q000235:genetics / Q000378:metabolism; D051379:Mice; D008819:Mice, Nude; D009190:Myelodysplastic Syndromes / Q000235:genetics / Q000378:metabolism* / Q000473:pathology; D041681:NIH 3T3 Cells; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D060888:Real-Time Polymerase Chain Reaction; D014162:Transfection
chemical_list: D002135:Calcium-Binding Proteins; C512941:DLK1 protein, human; D036341:Intercellular Signaling Peptides and Proteins; D008565:Membrane Proteins; D012333:RNA, Messenger