Paroxysmal nocturnal hemoglobinuria: analysis of the effects of mutant PIG-A on gene expression.
Compelling evidence indicates that mutations in PIG-A are necessary for the development of paroxysmal nocturnal hemaglobinuria (PNH), however, it is unclear why mutant PIG-A stem cells have a selective advantage. Further, multiple, discrete PIG-A mutations have been detected in the peripheral blood and bone marrow of patients with PNH, but the contribution of the different mutant clones to hematopoiesis is variable. This observation implies that factors in addition to mutant PIG-A influence the proliferative properties of the abnormal cells. To investigate the etiology of the selective advantage and the clonal dominance in PNH, gene expression in cells with mutant PIG-A was analyzed. Representational difference analysis was used to compare the pattern of cDNA expression between a human lymphoblastoid cell line with mutant PIG-A and its wild-type counterpart. These experiments demonstrated that the pattern of gene expression was different between the two cells lines in that the PIG-A mutant cells failed to express antiquitin mRNA. Transfection of the mutant cells with normal PIG-A restored expression of glycosyl phosphatidylinositol anchored proteins but not antiquitin. These experiments demonstrate that differences in the pattern of gene expression can occur independent of the PIG-A mutation. Depending upon the functional properties of the involved genes, these differences could influence the proliferative properties of PIG-A mutant cells and contribute to the selective advantage and clonal dominance that characterize PNH.
Kanai
N
N
Department of Medicine, Division of Hematology/Oncology, University of Utah Health Sciences Center and the Veterans Affairs Medical Center, Salt Lake City, Utah 84148, USA.
Vreeke
T M
TM
Parker
C J
CJ
D002460:Cell Line; D005434:Flow Cytometry; D015870:Gene Expression / Q000235:genetics; D008040:Genetic Linkage; D017261:Glycosylphosphatidylinositols / Q000172:deficiency* / Q000235:genetics; D006410:Hematopoiesis / Q000235:genetics; D006457:Hemoglobinuria, Paroxysmal / Q000235:genetics*; D006801:Humans; D008565:Membrane Proteins / Q000235:genetics*; D009154:Mutation; D012333:RNA, Messenger / Q000235:genetics; D020133:Reverse Transcriptase Polymerase Chain Reaction; D014162:Transfection; D014960:X Chromosome
D017261:Glycosylphosphatidylinositols; D008565:Membrane Proteins; D012333:RNA, Messenger; C080086:phosphatidylinositol glycan-class A protein