| |
|
|
|
|
|
|
|||
|
Prepublished online as a Blood First Edition Paper on September 26, 2002; DOI 10.1182/blood-2002-06-1685.
NEOPLASIA
From the Department of Hematology and Oncology,
Hannover Medical School, Germany; and the Department of Molecular
Biology, University of Tübingen, Germany.
Small interfering RNAs (siRNAs) were designed to target the
bcr-abl oncogene, which causes chronic myeloid leukemia
(CML) and bcr-abl-positive acute lymphoblastic leukemia (ALL).
Chemically synthesized anti-bcr-abl siRNAs were selected using
reporter gene constructs and were found to reduce bcr-abl mRNA up to
87% in bcr-abl-positive cell lines and in primary cells from CML
patients. This mRNA reduction was specific for bcr-abl because c-abl
and c-bcr mRNA levels remained unaffected. Furthermore, protein
expression of BCR-ABL and of laminA/C was reduced by specific
siRNAs up to 80% in bcr-abl-positive and normal
CD34+ cells, respectively. Finally, anti-bcr-abl siRNA
inhibited BCR-ABL-dependent, but not cytokine-dependent, proliferation
in a bcr-abl-positive cell line. These data demonstrate that siRNA can
specifically and efficiently interfere with the expression of an
oncogenic fusion gene in hematopoietic cells.
(Blood. 2003;101:1566-1569) RNA interference (RNAi) describes a highly
conserved regulatory mechanism that mediates sequence-specific
posttranscriptional gene silencing initiated by double-stranded RNA
(dsRNA).1-3 The RNase III enzyme Dicer processes dsRNA
into approximately 22-nucleotide (nt) small interfering RNAs
(siRNAs)4 that serve as guide sequences to
induce target-specific mRNA cleavage by the RNA-induced silencing complex RISC.5 In plants and
Caenorhabditis elegans, RNAi may involve
the amplification of dsRNA by an RNA-dependent RNA polymerase (RdRP),6 and it enables systemic, long-term, and heritable gene silencing. In contrast, RNAi in Drosophila and mammals
seems cell autonomous, transient, and nonheritable. Because exogenous application of siRNAs can efficiently trigger RNAi in mammalian cells,7,8 siRNAs are increasingly used in transient
(co)transfection assays to modulate gene expression in mammalian cells,
including human cells.9-12
Fusion transcripts encoding oncogenic proteins may represent potential
targets for a tumor-specific RNAi approach. The Philadelphia (Ph)
translocation t(9;22)(q34;q11) generates the bcr-abl fusion gene characteristic for chronic myelogenous leukemia (CML) and Ph+
acute lymphoblastic leukemia (ALL).13 Bcr-abl encodes a constitutively active cytoplasmic tyrosine kinase that is necessary and
sufficient to induce and maintain leukemic
transformation.14-16
We demonstrate that anti-bcr-abl siRNAs specifically inhibit bcr-abl
mRNA expression in hematopoietic cell lines and primary CML cells. They
reduce BCR-ABL protein expression and inhibit BCR-ABL-dependent, but
not cytokine-dependent, cell proliferation. Therefore, anti-bcr-abl
siRNAs may allow further analysis of BCR-ABL functions and, eventually,
may lead to RNAi-based therapeutics.
siRNAs
Transfection of hematopoietic cells
Real-time RT-PCR
Immunoblotting and immunofluorescence microscopy Cellular lysates from TonB cells were immunoblotted with polyclonal anti-bcr antibody (N-20) and polyclonal anti-Stat5 antibody (C-17) as described.18 To quantify transduction efficacy, laminA/C immunostaining was performed using a monoclonal anti-laminA/C antibody (sc-7292; all antibodies were from Santa Cruz Biotechnology, Santa Cruz, CA) as described.7Primary normal and CML cells Normal and CML CD34+ cells were purified to 95% or more, as described.19 Primary CD34+ cells or peripheral blood-derived mononuclear cells (PBMNCs) were cultured in X-VIVO/1% human serum albumin (HSA) with recombinant human stem cell factor (SCF; 100 ng/mL), Flt-3-ligand (100 ng/mL), and thrombopoietin (TPO; 20 ng/mL) before electroporation, and granulocyte macrophage-colony-stimulating factor (GM-CSF) and interleukin-3 (IL-3) (10 ng/mL each) were added thereafter. Methylcellulose colony assays were performed as described.19
Selection of anti-bcr-abl siRNAs Efficient siRNAs targeted against the b3a2-fusion sequence of bcr-abl were selected by cotransfection with a chimeric bcr-abl-enhanced green fluorescence protein (EGFP) reporter gene in HeLa cells. HeLa cells could be transfected up to 95% (data not shown). Of 4 chemically synthesized 21-nt siRNAs tested, b3a2_1 and b3a2_3 (Figure 1A) were the most efficient. They reduced the number of fluorescent cells (to 90%), bcr-abl-EGFP mRNA levels (to 87%), and fluorescence intensity per cell (up to 100-fold) 24 hours after transfection (data not shown). RNAi was specific because no reduction in fluorescence intensity was found with control siRNAs or when native EGFP without bcr-abl sequences was used as reporter. Furthermore, anti-b3a2-bcr-abl siRNA only reduced the b3a2-, but not the b2a2-, variant of a bcr-abl-EGFP reporter gene and vice versa (data not shown).Effects of siRNAs in hematopoietic cell lines The siRNAs b3a2_1 and b3a2_3 were tested in Ph+ K562 and TonB cells expressing bcr-abl under the control of a doxycycline-inducible promoter.17 Transfection efficacy was analyzed using the laminA/C system and reached approximately 80% in K562 cells (data not shown). After 24 and 48 hours, b3a2_1 and b3a2_3, but not control siRNAs, reduced bcr-abl mRNA levels up to 24.8% and 35.2% (b3a2_1) and 32.4% and 61% (b3a2_3), respectively (Tables 1 and 2 and data not shown). Notably, c-bcr and c-abl mRNA levels remained unaffected, demonstrating the specificity of anti-bcr-abl siRNAs (Tables 1-2). Furthermore, b3a2_1 and b3a2_3 transiently reduced the number of viable K562 cells by 75% in suspension cultures 4 days after electroporation (data not shown).
Cultures of TonB cells with or without doxycycline and IL-3 allow separate studies of BCR-ABL- and IL-3-mediated cell proliferation, with factor-independent proliferation considered as a surrogate marker for cellular transformation. After electroporation with b3a2_1 siRNA, bcr-abl mRNA declined by approximately 70% independent of IL-3 (Figure 1B). Furthermore, b3a2_1 siRNA reduced BCR-ABL protein expression by approximately 55%, as analyzed by immunoblotting and densitometry (Figure 1C). Finally, b3a2_1 siRNA reduced the number of viable TonB cells to an extent similar to that for the selective tyrosine kinase inhibitor STI571 in the absence, but not in the presence, of IL-3 (Figure 1D-E). Again, cultures of TonB cells treated with b3a2_1 resumed growth after 3 to 5 days in all conditions tested. In parental bcr-abl-negative BaF3 cells, siRNA had no effect on cell proliferation (data not shown). siRNA activity in primary hematopoietic cells siRNA efficacy in primary hematopoietic cells was first demonstrated in normal CD34+ cells using the laminA/C system. Anti-laminA/C siRNA reduced laminA/C protein expression by approximately 70% (Figure 1F). Next, electroporation of PBMNCs or purified CD34+ cells from 6 CML patients with b3a2_1 siRNA reduced bcr-abl mRNA levels by 50% to 79% compared with control siRNA (100%) (Table 1). Again, c-bcr and c-abl mRNA levels remained unchanged in both CML samples studied. When primary CML cells were transfected with b3a2_1 siRNA and grown in cytokine-supplemented liquid or semisolid cultures, no significant inhibition of cell proliferation or colony formation was observed (Table 2 and data not shown). In contrast, STI571 markedly reduced the number of viable cells in suspension cultures and the colony number derived from purified CD34+ cells, as shown in earlier studies22 (Table 2 and data not shown).Our data show gene suppression mediated by siRNA in normal and malignant hematopoietic cells. Specifically, siRNAs induced a specific but transient reduction of bcr-abl mRNA and protein expression, and an inhibition of BCR-ABL-mediated cell proliferation. As expected for mammalian cells,2,3,23 we found no evidence for transitive RNAi involving RdRP because anti-bcr-abl siRNAs did not affect c-bcr and c-abl mRNA levels. The markedly different effects of anti-bcr-abl siRNA and STI571 on CML cells in our study may be explained by the transient and nonheritable nature of RNAi in mammalian cells and the protein half-life of BCR-ABL. Alternatively, the inhibition of bcr-abl expression by siRNA or antisense sequences24 compared with blocking BCR-ABL kinase activity by STI571 may induce different phenotypes in cytokine-supplemented cultures of bcr-abl-positive cells.22,24 The molecular basis for these differences, and the kinetics of RNAi triggered by exogenous or endogenous expression of siRNAs,10,25 should be analyzed to better define the role of RNAi as scientific tools or potential therapeutics in human hematopoietic cells.
We thank George Daley (Massachusetts Institute of Technology, Cambridge, MA) for providing us with the TonB cell line used in this study. We thank Michael Morgan for critical reading of the manuscript and J. Deinhardt for help with the densitometric analysis.
Submitted June 11, 2002; accepted September 14, 2002.
Prepublished online as Blood First Edition Paper, September 26, 2002; DOI 10.1182/blood-2002-06-1685.
The publication costs of this article were defrayed in part by page charge payment. Therefore, and solely to indicate this fact, this article is hereby marked "advertisement" in accordance with 18 U.S.C. section 1734.
Reprints: Michaela Scherr or Matthias Eder, Medizinische Hochschule Hannover, Zentrum Innere Medizin, Abteilung Hämatologie und Onkologie, Carl-Neuberg Strasse 1, D-30625 Hannover, Germany; e-mail: m.scherr{at}t-online.de or eder.matthias{at}mh-hannover.de.
1. Fire A. RNA-triggered gene silencing. Trends Genet. 1999;15:358-363[CrossRef][Medline] [Order article via Infotrieve]. 2. Hannon GJ. RNA interference. Nature. 2002;418:244-251[CrossRef][Medline] [Order article via Infotrieve].
3.
Zamore PD.
Ancient pathways programmed by small RNAs.
Science.
2002;296:1265-1269 4. Bernstein E, Caudy AA, Hammond SM, Hannon GJ. Role for a bidentate ribonuclease in the initiation step of RNA interference. Nature. 2001;409:363-366[CrossRef][Medline] [Order article via Infotrieve]. 5. Hammond SM, Bernstein E, Beach D, Hannon GJ. An RNA-directed nuclease mediates post-transcriptional gene silencing in Drosophila cells. Nature. 2000;404:293-296[CrossRef][Medline] [Order article via Infotrieve]. 6. Sijen T, Fleenor J, Simmer F, et al. On the role of RNA amplification in dsRNA-triggered gene silencing. Cell. 2001;107:465-476[Medline] [Order article via Infotrieve]. 7. Elbashir SM, Harborth J, Lendeckel W, Yalcin A, Weber K, Tuschl T. Duplexes of 21-nucleotide RNAs mediate RNA interference in cultured mammalian cells. Nature. 2001;411:494-498[CrossRef][Medline] [Order article via Infotrieve].
8.
Caplen NJ, Parrish S, Imani F, Fire A, Morgan RA.
Specific inhibition of gene expression by small double-stranded RNAs in invertebrate and vertebrate systems.
Proc Natl Acad Sci U S A.
2001;98:9742-9747 9. Novina CD, Murray MF, Dykxhoorn DM, et al. siRNA-directed inhibition of HIV-1 infection. Nat Med. 2002;8:681-686[Medline] [Order article via Infotrieve]. 10. Lee NS, Dohjima T, Bauer G, et al. Expression of small interfering RNAs targeted against HIV-1 rev transcripts in human cells. Nat Biotechnol. 2002;20:500-505[Medline] [Order article via Infotrieve].
11.
Yang D, Buchholz F, Huang Z, et al.
Short RNA duplexes produced by hydrolysis with Escherichia coli RNase III mediate effective RNA interference in mammalian cells.
Proc Natl Acad Sci U S A.
2002;99:9942-9947 12. McCaffrey AP, Meuse L, Pham TT, Conklin DS, Hannon GJ, Kay MA. RNA interference in adult mice. Nature. 2002;418:38-39[CrossRef][Medline] [Order article via Infotrieve].
13.
Deininger MWN, Goldman JM, Melo JV.
The molecular biology of chronic myeloid leukemia.
Blood.
2000;96:3343-3356 14. Daley GQ, Van Etten RA, Baltimore D. Induction of chronic myelogenous leukemia in mice by the P210 bcr/abl gene of the Philadelphia chromosome. Science. 1990;247:824-830[Medline] [Order article via Infotrieve]. 15. Lugo T, Pendergast AM, Muller AJ, Witte ON. Tyrosine kinase activity and transformation potency of bcr-abl oncogene products. Science. 1990;247:1079-1082[Medline] [Order article via Infotrieve]. 16. Huettner CS, Zhang P, Van Etten RA, Tenen DG. Reversibility of acute B-cell leukaemia induced by BCR-ABL1. Nat Genet. 2000;24:57-60[CrossRef][Medline] [Order article via Infotrieve].
17.
Klucher KM, Lopez DV, Daley GQ.
Secondary mutation maintains the transformed state in BaF3 cells with inducible BCR/ABL expression.
Blood.
1998;91:3927-3934
18.
Kafert S, Luther S, Boll I, Wagner K, Ganser A, Eder M.
Functional analysis of a single chain chimeric
19.
Scherr M, Battmer K, Blomer U, et al.
Lentiviral gene transfer into peripheral blood-derived CD34+ NOD/SCID-repopulating cells.
Blood.
2002;99:709-712 20. Eder M, Battmer K, Kafert S, Stucki A, Ganser A, Hertenstein B. Monitoring of BCR-ABL expression using real-time RT-PCR in CML after bone marrow or peripheral blood stem cell transplantation. Leukemia. 1999;13:1383-1389[CrossRef][Medline] [Order article via Infotrieve]. 21. Scherr M, Battmer K, Bloemer U, Ganser A, Grez M. Determination of lentiviral vector particles using quantitative real-time PCR. Biotechniques. 2001;31:520-526[Medline] [Order article via Infotrieve]. 22. Druker BJ, Tamura S, Buchdunger E, et al. Effects of a selective inhibitor of the Abl tyrosine kinase on the growth of Bcr-abl-positive cells. Nat Med. 1996;2:561-566[Medline] [Order article via Infotrieve].
23.
Holen T, Amarzguioui M, Wiiger MT, Babaie E, Prydz H.
Positional effects of short interfering RNAs targeting the human coagulation trigger tissue factor.
Nucleic Acids Res.
2002;30:1757-1766 24. Martiat P, Lewalle P, Taj AS, et al. Retrovirally transduced antisense sequences stably suppress P210BCR-ABL expression and inhibit the proliferation of BCR/ABL-containing cell lines. Blood. 1993;81:502-509[Abstract].
25.
Brummelkamp TR, Bernards R, Agami R.
A system for stable expression of short interfering RNAs in mammalian cells.
Science.
2002;296:550-553
© 2003 by The American Society of Hematology.
| |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
![]() |
A. Puissant, S. Grosso, A. Jacquel, N. Belhacene, P. Colosetti, J.-P. Cassuto, and P. Auberger Imatinib mesylate-resistant human chronic myelogenous leukemia cell lines exhibit high sensitivity to the phytoalexin resveratrol FASEB J, June 1, 2008; 22(6): 1894 - 1904. [Abstract] [Full Text] [PDF] |
||||
![]() |
J. McLaughlin, D. Cheng, O. Singer, R. U. Lukacs, C. G. Radu, I. M. Verma, and O. N. Witte Sustained suppression of Bcr-Abl-driven lymphoid leukemia by microRNA mimics PNAS, December 18, 2007; 104(51): 20501 - 20506. [Abstract] [Full Text] [PDF] |
||||
![]() |
C. Diakos, G. Krapf, C. Gerner, A. Inthal, C. Lemberger, J. Ban, A. M. Dohnal, and E. R. Panzer-Gruemayer RNAi-mediated silencing of TEL/AML1 reveals a heat-shock protein- and survivin-dependent mechanism for survival Blood, March 15, 2007; 109(6): 2607 - 2610. [Abstract] [Full Text] [PDF] |
||||
![]() |
A BROZIK, N.P CASEY, C. HEGEDUS, A BORS, A KOZMA, H ANDRIKOVICS, M GEISZT, K NEMET, and M MAGOCSI Reduction of Bcr-Abl Function Leads to Erythroid Differentiation of K562 Cells via Downregulation of ERK Ann. N.Y. Acad. Sci., December 1, 2006; 1090(1): 344 - 354. [Abstract] [Full Text] [PDF] |
||||
![]() |
L. McCallum, S. Price, N. Planque, B. Perbal, A. Pierce, A. D. Whetton, and A. E. Irvine A novel mechanism for BCR-ABL action: stimulated secretion of CCN3 is involved in growth and differentiation regulation Blood, September 1, 2006; 108(5): 1716 - 1723. [Abstract] [Full Text] [PDF] |
||||
![]() |
V. Rapozzi, S. Cogoi, and L. E. Xodo Antisense locked nucleic acids efficiently suppress BCR/ABL and induce cell growth decline and apoptosis in leukemic cells. Mol. Cancer Ther., July 1, 2006; 5(7): 1683 - 1692. [Abstract] [Full Text] [PDF] |
||||
![]() |
N. Boissel, D. Rea, V. Tieng, N. Dulphy, M. Brun, J.-M. Cayuela, P. Rousselot, R. Tamouza, P. Le Bouteiller, F.-X. Mahon, et al. BCR/ABL oncogene directly controls MHC class I chain-related molecule A expression in chronic myelogenous leukemia. J. Immunol., April 15, 2006; 176(8): 5108 - 5116. [Abstract] [Full Text] [PDF] |
||||
![]() |
M. Scherr, A. Chaturvedi, K. Battmer, I. Dallmann, B. Schultheis, A. Ganser, and M. Eder Enhanced sensitivity to inhibition of SHP2, STAT5, and Gab2 expression in chronic myeloid leukemia (CML) Blood, April 15, 2006; 107(8): 3279 - 3287. [Abstract] [Full Text] [PDF] |
||||
![]() |
M. Thomas, A. Gessner, H.-P. Vornlocher, P. Hadwiger, J. Greil, and O. Heidenreich Targeting MLL-AF4 with short interfering RNAs inhibits clonogenicity and engraftment of t(4;11)-positive human leukemic cells Blood, November 15, 2005; 106(10): 3559 - 3566. [Abstract] [Full Text] [PDF] |
||||
![]() |
Z. Wang, J. Sampath, S. Fukuda, and L. M. Pelus Disruption of the Inhibitor of Apoptosis Protein Survivin Sensitizes Bcr-abl-Positive Cells to STI571-Induced Apoptosis Cancer Res., September 15, 2005; 65(18): 8224 - 8232. [Abstract] [Full Text] [PDF] |
||||
![]() |
J. Cortes and H. Kantarjian New Targeted Approaches in Chronic Myeloid Leukemia J. Clin. Oncol., September 10, 2005; 23(26): 6316 - 6324. [Abstract] [Full Text] [PDF] |
||||
![]() |
M. G. Andersson, P. C. J. Haasnoot, N. Xu, S. Berenjian, B. Berkhout, and G. Akusjarvi Suppression of RNA Interference by Adenovirus Virus-Associated RNA J. Virol., August 1, 2005; 79(15): 9556 - 9565. [Abstract] [Full Text] [PDF] |
||||
![]() |
C. A. Sledz and B. R. G. Williams RNA interference in biology and disease Blood, August 1, 2005; 106(3): 787 - 794. [Abstract] [Full Text] [PDF] |
||||
![]() |
M. Stevenson Therapeutic Potential of RNA Interference N. Engl. J. Med., October 21, 2004; 351(17): 1772 - 1777. [Full Text] [PDF] |
||||
![]() |
M. Shiota, M. Sano, M. Miyagishi, and K. Taira Ribozymes: Applications to Functional Analysis and Gene Discovery J. Biochem., August 1, 2004; 136(2): 133 - 147. [Abstract] [Full Text] [PDF] |
||||
![]() |
N. J. CAPLEN and S. MOUSSES Short Interfering RNA (siRNA)--Mediated RNA Interference (RNAi) in Human Cells Ann. N.Y. Acad. Sci., December 1, 2003; 1002(1): 56 - 62. [Abstract] [Full Text] [PDF] |
||||
![]() |
L. Wohlbold, H. van der Kuip, C. Miething, H.-P. Vornlocher, C. Knabbe, J. Duyster, and W. E. Aulitzky Inhibition of bcr-abl gene expression by small interfering RNA sensitizes for imatinib mesylate (STI571) Blood, September 15, 2003; 102(6): 2236 - 2239. [Abstract] [Full Text] [PDF] |
||||
![]() |
O. Heidenreich, J. Krauter, H. Riehle, P. Hadwiger, M. John, G. Heil, H.-P. Vornlocher, and A. Nordheim AML1/MTG8 oncogene suppression by small interfering RNAs supports myeloid differentiation of t(8;21)-positive leukemic cells Blood, April 15, 2003; 101(8): 3157 - 3163. [Abstract] [Full Text] [PDF] |
||||
![]() |
J. V. Melo, T. P. Hughes, and J. F. Apperley Chronic Myeloid Leukemia Hematology, January 1, 2003; 2003(1): 132 - 152. [Abstract] [Full Text] [PDF] |
||||
| ||||||||||||||