耐STI571的K562细胞株的建立及抗STI571耐药的BCR-ABL选择性抑制剂的筛选
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摘要
慢性髓性白血病是一种起源于造血多功能细胞的恶性增生性疾病,约占成人白血病的15%可分为慢性期﹑加速期﹑急变期,一般病程持续4年左右,随着疾病进展面对治疗逐渐不敏感。
本文建立了针对STI571的人白血病耐药细胞株K562/R,耐STI57倍数约为235,该耐药细胞株对HHT﹑VCR﹑DNR具有不同程度的交叉耐药性。与亲代敏感株K562细胞相比,线粒体膜电位显著提高对抗凋亡能力明显增强、bcr-abl和mdr1基因的上调,bcr-abl蛋白及其激酶以及Pgp糖蛋白的过度表达。此外,发现bcr-abl激酶区的第231位氨基酸发生突变。应用MTT法筛选出1个能选择性抑制K562/R细胞生长﹑增殖的化合物。成功建立了一株针对STI571耐药的BCR-ABL+白血病细胞系,该细胞BCR-ABL激酶活性以及抗凋亡能力显著增强,并具有明确的抗多药耐药的特征。为体外筛选抗STI571耐药的选择性抑制剂提供了有效的实验平台。
Targeting the tyrosine kinase activity of Bcr-Abl with STI571 is anattractive therapeutic strategy in chronic myelogenous leukemia (CML). Afew CML cell lines and primary progenitors are, however, resistant to thiscompound.
The t(9;22)(q34;q11) reciprocal chromosomal translocation occurs innearly all patients with chronic myelogenous leukemia (CML) and inapproximately 25% of adults and 5% of children with acute lymphoblasticleukemia (ALL). This translocation gives origin to a 22q , or Philadelphia(Ph), chromosome that contains a BCR-ABL hybrid gene, the molecularhallmark of CML and of Ph-positive ALL.BCR-ABL encodes an oncogenicfusion protein of 190, 210, or 230 kd, depending on the breakpoint on theBCR gene .The unifying feature of all these Bcr-Abl fusion proteins is theirderegulated protein tyrosine kinase activity. The latter is responsible for thein vitro transformation effect and the in vivo leukemogenic property ofBcr-Abl.Targeting the tyrosine kinase activity of Bcr-Abl is, therefore, anattractive therapeutic strategy in CML or in BCR-ABL-positive ALL.Toward this aim, several inhibitors of tyrosine kinase were recentlydeveloped.Among these molecules, STI571, previously known asCGP57148B, a 2-phenylaminopyrimidine derivative, is among the mostpromising and selective inhibitors of Bcr-Abl tyrosine kinase activity. Itinhibits competitively the binding of adenosine triphosphate (ATP) to thekinase domain of Abl at micromolar concentrations. Most otherserine/threonine and tyrosine kinases are unaffected, but there is a
suppressive effect against the Kit and PDGF receptor kinase activities.Most study have reported that STI571 specifically abrogates CMLgranulocyte macrophage-colony-forming unit (GM-CFU) and erythroidburst-forming unit (BFU-e) colony formation over a 2-log dose range, witha maximum differential effect at 1 μmol/L. The inhibitor also suppressesproliferation of most Ph-positive cell lines.Nevertheless, a fewBCR-ABL-positive GM-CFU colonies from peripheral blood or bonemarrow survive in the presence of the compound, and 2 of 10 Ph-positivecell lines were found to be resistant to STI571.The reasons for this reducedsensitivity to STI571 in some cells is unknown, but it is an issue ofconsiderable relevance as this compound enters clinical trials.We investigated the mechanism of this resistance in two human celllines from which sensitive (s) and resistant (r) clones were generated byvarious methods. Although the resistant cells were able to survive in thepresence of STI571, its proliferation was almost close to that of theirsensitive counterparts in the absence of the compound. The concentrationof STI571 needed for a 50% reduction in viable cells after a 3-dayexposure was on average 235 times higher in the resistant (2.35 μmol/L)than in the sensitive (0.01 μmol/L) clones. The mechanism of resistance toSTI571 varied among the cell line. Thus, in K562/R, there wasup-regulation of the Bcr-Abl protein associated with amplification of theBCR-ABL gene. Sequencing of the Abl kinase domain revealed onemutation—K231N. The multidrug resistance P-glycoprotein (Pgp) wasalso overexpressed in K562/R, indicating that at least 2 mechanisms ofresistance operate in this cell line.
In conclusion, our data show that resistance to STI571 inBCR-ABL-positive cells is a rare phenomenon and may develop throughmultiple mechanisms, such as Bcr-Abl overexpression, reduction in theuptake of the compound by Pgp overexpression, or possibly by excessivedegradation. We cannot exclude that the acquisition of compensatorymutations in genes other than BCR-ABL also plays a part. It is possible thatthe same or similar mechanisms operate in a few primary CMLprogenitors that escape the in vitro antiproliferative effect of thecompound. Overall, our data suggest that BCR-ABL-positive cells canevade the inhibitory effect of this tyrosine kinase inhibitor by variousmechanisms.
本文建立了针对STI571的人白血病耐药细胞株K562/R,耐STI57倍数约为235,该耐药细胞株对HHT﹑VCR﹑DNR具有不同程度的交叉耐药性。与亲代敏感株K562细胞相比,线粒体膜电位显著提高对抗凋亡能力明显增强、bcr-abl和mdr1基因的上调,bcr-abl蛋白及其激酶以及Pgp糖蛋白的过度表达。此外,发现bcr-abl激酶区的第231位氨基酸发生突变。应用MTT法筛选出1个能选择性抑制K562/R细胞生长﹑增殖的化合物。成功建立了一株针对STI571耐药的BCR-ABL+白血病细胞系,该细胞BCR-ABL激酶活性以及抗凋亡能力显著增强,并具有明确的抗多药耐药的特征。为体外筛选抗STI571耐药的选择性抑制剂提供了有效的实验平台。
Targeting the tyrosine kinase activity of Bcr-Abl with STI571 is anattractive therapeutic strategy in chronic myelogenous leukemia (CML). Afew CML cell lines and primary progenitors are, however, resistant to thiscompound.
The t(9;22)(q34;q11) reciprocal chromosomal translocation occurs innearly all patients with chronic myelogenous leukemia (CML) and inapproximately 25% of adults and 5% of children with acute lymphoblasticleukemia (ALL). This translocation gives origin to a 22q , or Philadelphia(Ph), chromosome that contains a BCR-ABL hybrid gene, the molecularhallmark of CML and of Ph-positive ALL.BCR-ABL encodes an oncogenicfusion protein of 190, 210, or 230 kd, depending on the breakpoint on theBCR gene .The unifying feature of all these Bcr-Abl fusion proteins is theirderegulated protein tyrosine kinase activity. The latter is responsible for thein vitro transformation effect and the in vivo leukemogenic property ofBcr-Abl.Targeting the tyrosine kinase activity of Bcr-Abl is, therefore, anattractive therapeutic strategy in CML or in BCR-ABL-positive ALL.Toward this aim, several inhibitors of tyrosine kinase were recentlydeveloped.Among these molecules, STI571, previously known asCGP57148B, a 2-phenylaminopyrimidine derivative, is among the mostpromising and selective inhibitors of Bcr-Abl tyrosine kinase activity. Itinhibits competitively the binding of adenosine triphosphate (ATP) to thekinase domain of Abl at micromolar concentrations. Most otherserine/threonine and tyrosine kinases are unaffected, but there is a
suppressive effect against the Kit and PDGF receptor kinase activities.Most study have reported that STI571 specifically abrogates CMLgranulocyte macrophage-colony-forming unit (GM-CFU) and erythroidburst-forming unit (BFU-e) colony formation over a 2-log dose range, witha maximum differential effect at 1 μmol/L. The inhibitor also suppressesproliferation of most Ph-positive cell lines.Nevertheless, a fewBCR-ABL-positive GM-CFU colonies from peripheral blood or bonemarrow survive in the presence of the compound, and 2 of 10 Ph-positivecell lines were found to be resistant to STI571.The reasons for this reducedsensitivity to STI571 in some cells is unknown, but it is an issue ofconsiderable relevance as this compound enters clinical trials.We investigated the mechanism of this resistance in two human celllines from which sensitive (s) and resistant (r) clones were generated byvarious methods. Although the resistant cells were able to survive in thepresence of STI571, its proliferation was almost close to that of theirsensitive counterparts in the absence of the compound. The concentrationof STI571 needed for a 50% reduction in viable cells after a 3-dayexposure was on average 235 times higher in the resistant (2.35 μmol/L)than in the sensitive (0.01 μmol/L) clones. The mechanism of resistance toSTI571 varied among the cell line. Thus, in K562/R, there wasup-regulation of the Bcr-Abl protein associated with amplification of theBCR-ABL gene. Sequencing of the Abl kinase domain revealed onemutation—K231N. The multidrug resistance P-glycoprotein (Pgp) wasalso overexpressed in K562/R, indicating that at least 2 mechanisms ofresistance operate in this cell line.
In conclusion, our data show that resistance to STI571 inBCR-ABL-positive cells is a rare phenomenon and may develop throughmultiple mechanisms, such as Bcr-Abl overexpression, reduction in theuptake of the compound by Pgp overexpression, or possibly by excessivedegradation. We cannot exclude that the acquisition of compensatorymutations in genes other than BCR-ABL also plays a part. It is possible thatthe same or similar mechanisms operate in a few primary CMLprogenitors that escape the in vitro antiproliferative effect of thecompound. Overall, our data suggest that BCR-ABL-positive cells canevade the inhibitory effect of this tyrosine kinase inhibitor by variousmechanisms.
引文
1 Deininger MW,Goldman Kottke TJ,Melo JV. The molecular biology of chronic myeloid leukemia.Blood,2000,96:3343~3356.
2 Sun X,Layton JE,Elefanty A,et al.Blood,2001,97:2008.
3 Levitzki A,Gazit A.Science,1995,267:1782
4 Schindler T.Brrnmann W,Pcllicena P,et al.Structural mechanism for STI571 inhibition of Abelon tyrosine kinase,[J]. Science,2000,289:1938.
5 Le Coutre P,Tassi E.Varella-Garcia M,et al,Blood,2000,95:1758.
6 Kurzrock R,Gutterman JU,Talpaz M.The molecular genetics of Philadelphia chromosome-positive leukemia.[J].N EngM,1998,391(15):990.
7 Mahon FX,Deininger MW,Schulthcis B,et al. Selection and characterization of BCR-ABL positive cell lines with differential sensitivity to the tyrosine kinase inhibitor STI571:diverse mechanisms of resistance.Blood,2000,96:1070~1079.
8 Van Etten RA.Curr Opin Hematol,2001,8:224.
9 Beham-Schmid C,Apfelbeck U,Sill H,et al.Blood,2002,99:381.
10 Mahon FX.Deininger MW,Schultheis B,et al.Selection and characterization of BCR-ABL positive cell line to acquire a drug-resistant phenotype.Leukemia,2001,15:1823~1833.
11 Weisberg E,Griffin JD.Mechanism of resistance to the ABL tyrosine kinase inhibitor STI571 in BCR/ABL-transformed hematopoietic cell lines.Blood,2000,95:3498~3505.
12 Le Coutre P,Tassi E,Varellar-Gareia M,et al.Induction of resistance to the Abelson inhibitor STI571 in human leukemia cells through gene amplification.Blood,2000,95:1758~1766.
13 Susan Branford,Zbigniew Rudzki,Sonya Walsh,et al.Detection of BCR-ABL mutations in patients with CML treated with imatinib is virtually always accompanied by clinical resistance ,and mutations in the ATP phosphate-bingding loop(P-loop) are associated with a poor prognosis.Blood,2003,102:276~283.
14 Alex J.Tipping,Francois X.Mahon,et al.Restoration of sensitivity to STI571 in STI571-resistant chronic myeloid leukemia cells .Blood,2001,98:3864~3867.
15 Mercedes E,Gorre,Mansoor Mohammed,et al.Clinical resistance to STI571 cancer therpy caused by BCR-ABL gene mutation or amplification.Science,2001,293:876~880.
16 Von Bubnoff N.Peschel C,Duyster J.Resistance of Philadephia chromosome positive leukemia towards the kinase inhibitor imatinib (STI571,Gleevec):at target oncoprote in strikes back.[J].Leukemia,2003,17(5):829~838.
17Amie S.Corbin,Paul La Rosee,Eric P,Stoffregen,et al.Several Bcr-Abl kinase domain mutants associated with imatinib mesylate resistance remain sensitive to inmatinib.Blood,2002,12:3659.
18 Tesyzo Tauchi,Kazuma Ohyashi Ki.Molecular mechanisms of resistance of leukemia to inmatinib mesylate.Leukemia Research,2004,28:39~45.
19 Michael W.N.Deininger,Brian J.Druker.Specific targeted therapy of chronic myelogenous leukemia with imatinib.Pharmacol Rev,2003,55:401~423.
20 Michael E O'Dwyer,Brian J Druker.STI571: an inhibitor of the BCR-ABL tyrosine kinase for the treatment of chronic myelogenous leukemia .Lancet Oncol,2000,1:207~211.
21Amie S.Corbin,Elisabeth Buchdunger,et al.Analysis of the structural basis of specificity of inhibition of the Abl kinase by STI571.The Journal of Biological Chemistry,2002,277(35):32214~32219.
22 Carlo B Gambacorti-Passerini,Rosalind H Gunby,et al.Molecular mechanism of resistance to imatinib in Philadelphia-chromosome-positive.leukemias.Lancet Oncol,2003,4:75~85.
23 Michael Deininger,Elisabeth Buchdunger,Brian J.Druker.The development of imatinib as a therapeutic agent for chronic myeloid leukemia.Blood,2005,100:2640~2653.
24 Shah NP,Nicol JM,Nagar B,et al.Multiple BCR-ABL kinase domain mutations confer polyclonal resistance to the tyrosine kinase inhibitor imatinib(STI571) in chronic phase and blast crisis chironic myeloid leukemia .Cancer Cell,2002,2:117~125.
25 Von Bubnoff N,Schneller F,Peschel C,Duyster J.BCR-ABL gene mutations in relation to clinical resistance of Philadelphia-chromosome-positive leukemia to STI571:a prospective study.Lancet,2002,359:487~491.
26 Jurgensen HG.Elliott MA,Allan EK,et al.Aopha1-acid glycorprotein expressed in the plasma of chronic myeloid leukemia patients does not mediate significant in vitro resistance to STI571.Blood,2002,99(2):713~715.
27 La Rosee P,Corbin AS,Stoffregen EP,et al.Activity of Bcr-Abl kinase inhibitor PD180970 against clinically relevant Bcr-Abl isoforms that cause resistance to imatinib mesylate (Gleevec,STI571).Cancer Res,2002,62(24):7149~7153.
28 Clarkson B.Strife A.Wismeuski D,et al.Chronic myelogenous leukemia as a paradigm of early cancer and possible curative strategies.[J].Leukemia,2003,17(7):1211~1262.
29Cortes J,Kantarjian H.Advanced-phase chronic myeloid leukemia [J].Semin Hematol,2003.40(1):74~86.
30 Mahon F X.Bellose F,Lagarade V.et al.MDR-1 gene over expression confers resistance to imatinib mesylate in leukemia cell line models.[J].Blood,2003,101(6):2368~2373.
31 Widmer N,Colonbo S,Buclin J,et al.Functional consequence of MDR-1 expression on imatinib intracellular concentration .[J].Blood,2003.102(3):1142.
32 Ren R.Mechanisms of BCR-ABL in the pathogenesis of chronic myelogenous leukemia .Nat Rev Cancer,2005,5(3):172~183.
33 Scherr M,Battmer K,et al.Stable RNA interference (RNAi) as an option for anti-bcr-abl therapy.Gene.Ther,2005,12(1):12~21.
34 Cormick FM.New-age drug meets resistance.[J].Nature,2001,412(19):281.
35 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.Nature Med,1996.2:561~566.
36 Rowfey JD.Nature,1973. 243: 290.
37 Ravani F,Cortes J,Albitar M,et al.Br J Haematol,1999.107:581.
38 Le Coutre P,Mologni L,Cleris L.et al.In vivo eradication of human BCR-ABL-positive leukemia cells with an ABL kinase inhibitor.J Natl Cancer Inst,1999.91:163~168.
39 Gambacorti-Passcrini C,Barni R,Le Coutre P,et al.JNarl Cancer Inst ,2000.92:1641.
40 Shoichet BK,Bodian DL,Kuntz ID.Molecular docking using shape descriptors.J Comp Chem,1992.13(3):380~397.
41 彭晖,齐静,黄牛等BCR-ABL酪氨酸激酶抑制剂的分子设计及其生物活性。中国医学科学院学报。2004,26(2):145~149。
42 Druker BJ.Imatinib alone and in combination for chronic myeloid leukaemia ,[J].SeminHematol,2003.40(1):50~58.
43 Wei-Hua Liu,G.Mike Makrigiorgos,et al.Sensitive and quantitative detection of mutationsassociated with clinical resistance to STI571.Leukemia Research,2003.27:979~982.
44 Roche-Lestienne C,Soenen-Corna V,Grardel-Duflos N,et al.Several types of mutations ofthe Abl gene can be found in chronic myeloid leukaemia patients resistance to STI571andthey can pre-exist to the onset of treatment.Blood,2002.100:1014~1018.
46 刑文。STI571在白血病治疗中耐药机制的研究。国外医学输血及血液学分册,2004.27(1):41~44。
47 俞文娟。STI571的耐药机制及其克服对策。国外医学输血及血液学分册,2003,26(3):1~5。
2 Sun X,Layton JE,Elefanty A,et al.Blood,2001,97:2008.
3 Levitzki A,Gazit A.Science,1995,267:1782
4 Schindler T.Brrnmann W,Pcllicena P,et al.Structural mechanism for STI571 inhibition of Abelon tyrosine kinase,[J]. Science,2000,289:1938.
5 Le Coutre P,Tassi E.Varella-Garcia M,et al,Blood,2000,95:1758.
6 Kurzrock R,Gutterman JU,Talpaz M.The molecular genetics of Philadelphia chromosome-positive leukemia.[J].N EngM,1998,391(15):990.
7 Mahon FX,Deininger MW,Schulthcis B,et al. Selection and characterization of BCR-ABL positive cell lines with differential sensitivity to the tyrosine kinase inhibitor STI571:diverse mechanisms of resistance.Blood,2000,96:1070~1079.
8 Van Etten RA.Curr Opin Hematol,2001,8:224.
9 Beham-Schmid C,Apfelbeck U,Sill H,et al.Blood,2002,99:381.
10 Mahon FX.Deininger MW,Schultheis B,et al.Selection and characterization of BCR-ABL positive cell line to acquire a drug-resistant phenotype.Leukemia,2001,15:1823~1833.
11 Weisberg E,Griffin JD.Mechanism of resistance to the ABL tyrosine kinase inhibitor STI571 in BCR/ABL-transformed hematopoietic cell lines.Blood,2000,95:3498~3505.
12 Le Coutre P,Tassi E,Varellar-Gareia M,et al.Induction of resistance to the Abelson inhibitor STI571 in human leukemia cells through gene amplification.Blood,2000,95:1758~1766.
13 Susan Branford,Zbigniew Rudzki,Sonya Walsh,et al.Detection of BCR-ABL mutations in patients with CML treated with imatinib is virtually always accompanied by clinical resistance ,and mutations in the ATP phosphate-bingding loop(P-loop) are associated with a poor prognosis.Blood,2003,102:276~283.
14 Alex J.Tipping,Francois X.Mahon,et al.Restoration of sensitivity to STI571 in STI571-resistant chronic myeloid leukemia cells .Blood,2001,98:3864~3867.
15 Mercedes E,Gorre,Mansoor Mohammed,et al.Clinical resistance to STI571 cancer therpy caused by BCR-ABL gene mutation or amplification.Science,2001,293:876~880.
16 Von Bubnoff N.Peschel C,Duyster J.Resistance of Philadephia chromosome positive leukemia towards the kinase inhibitor imatinib (STI571,Gleevec):at target oncoprote in strikes back.[J].Leukemia,2003,17(5):829~838.
17Amie S.Corbin,Paul La Rosee,Eric P,Stoffregen,et al.Several Bcr-Abl kinase domain mutants associated with imatinib mesylate resistance remain sensitive to inmatinib.Blood,2002,12:3659.
18 Tesyzo Tauchi,Kazuma Ohyashi Ki.Molecular mechanisms of resistance of leukemia to inmatinib mesylate.Leukemia Research,2004,28:39~45.
19 Michael W.N.Deininger,Brian J.Druker.Specific targeted therapy of chronic myelogenous leukemia with imatinib.Pharmacol Rev,2003,55:401~423.
20 Michael E O'Dwyer,Brian J Druker.STI571: an inhibitor of the BCR-ABL tyrosine kinase for the treatment of chronic myelogenous leukemia .Lancet Oncol,2000,1:207~211.
21Amie S.Corbin,Elisabeth Buchdunger,et al.Analysis of the structural basis of specificity of inhibition of the Abl kinase by STI571.The Journal of Biological Chemistry,2002,277(35):32214~32219.
22 Carlo B Gambacorti-Passerini,Rosalind H Gunby,et al.Molecular mechanism of resistance to imatinib in Philadelphia-chromosome-positive.leukemias.Lancet Oncol,2003,4:75~85.
23 Michael Deininger,Elisabeth Buchdunger,Brian J.Druker.The development of imatinib as a therapeutic agent for chronic myeloid leukemia.Blood,2005,100:2640~2653.
24 Shah NP,Nicol JM,Nagar B,et al.Multiple BCR-ABL kinase domain mutations confer polyclonal resistance to the tyrosine kinase inhibitor imatinib(STI571) in chronic phase and blast crisis chironic myeloid leukemia .Cancer Cell,2002,2:117~125.
25 Von Bubnoff N,Schneller F,Peschel C,Duyster J.BCR-ABL gene mutations in relation to clinical resistance of Philadelphia-chromosome-positive leukemia to STI571:a prospective study.Lancet,2002,359:487~491.
26 Jurgensen HG.Elliott MA,Allan EK,et al.Aopha1-acid glycorprotein expressed in the plasma of chronic myeloid leukemia patients does not mediate significant in vitro resistance to STI571.Blood,2002,99(2):713~715.
27 La Rosee P,Corbin AS,Stoffregen EP,et al.Activity of Bcr-Abl kinase inhibitor PD180970 against clinically relevant Bcr-Abl isoforms that cause resistance to imatinib mesylate (Gleevec,STI571).Cancer Res,2002,62(24):7149~7153.
28 Clarkson B.Strife A.Wismeuski D,et al.Chronic myelogenous leukemia as a paradigm of early cancer and possible curative strategies.[J].Leukemia,2003,17(7):1211~1262.
29Cortes J,Kantarjian H.Advanced-phase chronic myeloid leukemia [J].Semin Hematol,2003.40(1):74~86.
30 Mahon F X.Bellose F,Lagarade V.et al.MDR-1 gene over expression confers resistance to imatinib mesylate in leukemia cell line models.[J].Blood,2003,101(6):2368~2373.
31 Widmer N,Colonbo S,Buclin J,et al.Functional consequence of MDR-1 expression on imatinib intracellular concentration .[J].Blood,2003.102(3):1142.
32 Ren R.Mechanisms of BCR-ABL in the pathogenesis of chronic myelogenous leukemia .Nat Rev Cancer,2005,5(3):172~183.
33 Scherr M,Battmer K,et al.Stable RNA interference (RNAi) as an option for anti-bcr-abl therapy.Gene.Ther,2005,12(1):12~21.
34 Cormick FM.New-age drug meets resistance.[J].Nature,2001,412(19):281.
35 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.Nature Med,1996.2:561~566.
36 Rowfey JD.Nature,1973. 243: 290.
37 Ravani F,Cortes J,Albitar M,et al.Br J Haematol,1999.107:581.
38 Le Coutre P,Mologni L,Cleris L.et al.In vivo eradication of human BCR-ABL-positive leukemia cells with an ABL kinase inhibitor.J Natl Cancer Inst,1999.91:163~168.
39 Gambacorti-Passcrini C,Barni R,Le Coutre P,et al.JNarl Cancer Inst ,2000.92:1641.
40 Shoichet BK,Bodian DL,Kuntz ID.Molecular docking using shape descriptors.J Comp Chem,1992.13(3):380~397.
41 彭晖,齐静,黄牛等BCR-ABL酪氨酸激酶抑制剂的分子设计及其生物活性。中国医学科学院学报。2004,26(2):145~149。
42 Druker BJ.Imatinib alone and in combination for chronic myeloid leukaemia ,[J].SeminHematol,2003.40(1):50~58.
43 Wei-Hua Liu,G.Mike Makrigiorgos,et al.Sensitive and quantitative detection of mutationsassociated with clinical resistance to STI571.Leukemia Research,2003.27:979~982.
44 Roche-Lestienne C,Soenen-Corna V,Grardel-Duflos N,et al.Several types of mutations ofthe Abl gene can be found in chronic myeloid leukaemia patients resistance to STI571andthey can pre-exist to the onset of treatment.Blood,2002.100:1014~1018.
46 刑文。STI571在白血病治疗中耐药机制的研究。国外医学输血及血液学分册,2004.27(1):41~44。
47 俞文娟。STI571的耐药机制及其克服对策。国外医学输血及血液学分册,2003,26(3):1~5。