WT1 and BCR-ABL specific small interfering RNA have additive effects in the induction of apoptosis in leukemic cells

• Published in: Haematologica (Roma) Vol. 90; no. 3; pp. 326 - 334
• Main Authors: Elmaagacli, AH, Koldehoff, M, Peceny, R, Klein-Hitpass, L, Ottinger, H, Beelen, DW, Opalka, B
• Format: Journal Article
• Language: English
• Published: Pavia Haematologica 01-03-2005
• Subjects: Apoptosis - drug effects; Biological and medical sciences; Chromosome aberrations; Drug Synergism; Fusion Proteins, bcr-abl - drug effects; Fusion Proteins, bcr-abl - genetics; Gene Expression Regulation, Neoplastic - drug effects; Hematologic and hematopoietic diseases; Humans; Leukemia - drug therapy; Leukemia - pathology; Leukemias. Malignant lymphomas. Malignant reticulosis. Myelofibrosis; Medical genetics; Medical sciences; RNA, Small Interfering - pharmacology; RNA, Small Interfering - therapeutic use; Tumor Cells, Cultured; WT1 Proteins - drug effects; WT1 Proteins - genetics; Chromosomal aberration; Hematology; RNA; Enzyme; Transferases; Leukemia; BCR-ABL; Malignant hemopathy; Wilms tumor gene; small interfering RNA; Philadelphia chromosome; Abnormal chromosome C9; Additive; Cell death; Protein kinase; Bcr-abl protein; WT1; Abnormal chromosome G22; Abnormal chromosome; Hybrid gene; Apoptosis; Chromosome translocation
• ISSN: 0390-6078; 1592-8721

Department of Bone Marrow Transplantation, University Hospital of Essen, Hufelandstr. 55, 45122 Essen, Germany. [e-mail]
BACKGROUND AND OBJECTIVES: The Wilms' tumor gene (WT1) is aberrantly over-expressed in leukemic cells. Therefore, we wanted to study the effect of small interfering (siRNA) targeting WT1 in leukemic cells and normal CD34-positive cells with regard to proliferation, induction of apoptosis, and cell differentiation. Furthermore, we wanted to evaluate whether the additional use of BCR-ABL siRNA could increase the anti-leukemic effects of WT1 siRNA in chronic myeloid leukemia (CML) cells. DESIGN AND METHODS: We measured WT1 expression by reverse transcription polymerase chain reaction (RT-PCR) in various cell lines and in leukemic cells from patients, then transfected the cells with WT1-specific and BCR-ABL-specific siRNA before carrying out microarray analysis. We used the tunnel assay to measure apoptotic cells. RESULTS: We observed a reduction of WT1 gene expression, measured by real-time RT-PCR, in all studied cell lines: K-562, Kasumi-1, MV 4-11 and NB-4, as well as in cells of AML and CML patients. The results also demonstrated that WT1 siRNA significantly induced apoptosis and inhibited proliferation in MV4-11 cells, NB-4 cells, Kasumi-1 cells (p