Abnormal cytoplasmic dyslocalisation and/or reduction of nucleophosmin protein level rarely occurs in myelodysplastic syndromes.
The Nucleophosmin1 (NPM1) gene located in chromosome 5q35 is affected by chromosomal translocation, mutation and deletion in myelodysplastic syndrome (MDS) and acute myeloid leukemia (AML). NPM1 haploinsufficiency reportedly causes MDS-like disorders in knockout mice. Here, we studied mRNA and protein expression in bone marrow (BM) samples from 36 patients with MDS. The NPM1 expression levels of mRNA and protein were not related to chromosome 5 abnormalities and were almost the same as those in normal BM and AML cells. However, the protein levels in AML cells with NPM1 mutations were slightly lower than in those without mutation. Immunochemical studies showed no difference in the staining intensity and subcellular localisation between MDS and normal BM cells. It was concluded that abnormal cytoplasmic localisation and/or significant reduction of NPM1 protein level rarely occurs in MDS. The increase in the number of nuclear NPM1-positive cells may be related to the progression of MDS.
Ishikawa
Yuichi
Y
Department of Hematology and Oncology, Nagoya University Graduate School of Medicine, and Department of Infectious Diseases, Nagoya University Hospital, Showa-ku, Nagoya, Japan. yishikaw@med.nagoya-u.ac.jp
Xu
Jinglan
J
Sakashita
Gyosuke
G
Urano
Takeshi
T
Suzuki
Tatsuya
T
Tomita
Akihiro
A
Kiyoi
Hitoshi
H
Nakamura
Shigeo
S
Naoe
Tomoki
T
D001853:Bone Marrow / Q000737:chemistry* / Q000473:pathology; D002869:Chromosome Aberrations; D003593:Cytoplasm / Q000737:chemistry*; D018450:Disease Progression; D006801:Humans; D009154:Mutation; D009190:Myelodysplastic Syndromes / Q000235:genetics* / Q000378:metabolism / Q000473:pathology; D009687:Nuclear Proteins / Q000032:analysis* / Q000235:genetics*; D000090243:Nucleophosmin; D012333:RNA, Messenger / Q000032:analysis
C000716967:NPM1 protein, human; C000715570:Npm1 protein, mouse; D009687:Nuclear Proteins; D012333:RNA, Messenger; D000090243:Nucleophosmin