Department of Bone Marrow Transplantation, West German Cancer Center, University Hospital of Duisburg-Essen, Hufelandstr. 55 45122 Essen, Germany.
Haematologica. 2010 Mar;95(3):388-97. doi: 10.3324/haematol.2009.016063.
Selective inhibition of the BCR-ABL tyrosine kinase by RNA interference has been demonstrated in leukemic cells. We, therefore, evaluated specific BCR-ABL small interfering RNA silencing in BCR-ABL-positive cell lines, including those resistant to imatinib and particularly those with the T315I mutation.
The factor-independent 32Dp210 BCR-ABL oligoclonal cell lines and human imatinib-resistant BCR-ABL-positive cells from patients with leukemic disorders were investigated. The effects of BCR-ABL small interfering RNA or the combination of BCR-ABL small interfering RNA with imatinib and nilotinib were compared with those of the ABL inhibitors imatinib and nilotinib.
Co-administration of BCR-ABL small interfering RNA with imatinib or nilotinib dramatically reduced BCR-ABL expression in wild-type and mutated BCR-ABL cells and increased the lethal capacity. BCR-ABL small interfering RNA significantly induced apoptosis and inhibited proliferation in wild-type (P<0.0001) and mutated cells (H396P, T315I, P<0.0001) versus controls. Co-treatment with BCR-ABL small interfering RNA and imatinib or nilotinib resulted in increased inhibition of proliferation and induction of apoptosis in T315I cells as compared to imatinib or nilotinib alone (P<0.0001). Furthermore, the combination of BCR-ABL small interfering RNA with imatinib or nilotinib significantly (P<0.01) reversed multidrug resistance-1 gene-dependent resistance of mutated cells. In T315I cells BCR-ABL small interfering RNA with nilotinib had powerful effects on cell cycle distribution.
Our data suggest that silencing by BCR-ABL small interfering RNA combined with imatinib or nilotinib may be associated with an additive antileukemic activity against tyrosine kinase inhibitor-sensitive and resistant BCR-ABL cells, and might be an alternative approach to overcome BCR-ABL mutations.
RNA 干扰对 BCR-ABL 酪氨酸激酶的选择性抑制已在白血病细胞中得到证实。因此，我们评估了 BCR-ABL 阳性细胞系中 BCR-ABL 特异性小干扰 RNA 沉默，包括对伊马替尼耐药的细胞系，特别是 T315I 突变的细胞系。
我们研究了无细胞因子依赖的 32Dp210 BCR-ABL 寡克隆细胞系和来自白血病患者的人伊马替尼耐药 BCR-ABL 阳性细胞系。比较了 BCR-ABL 小干扰 RNA 或 BCR-ABL 小干扰 RNA 联合伊马替尼和尼洛替尼与 ABL 抑制剂伊马替尼和尼洛替尼的作用。
BCR-ABL 小干扰 RNA 联合伊马替尼或尼洛替尼可显著降低野生型和突变型 BCR-ABL 细胞中的 BCR-ABL 表达，并增加致死能力。BCR-ABL 小干扰 RNA 显著诱导野生型（P<0.0001）和突变型细胞（H396P、T315I、P<0.0001）的细胞凋亡和抑制增殖，与对照组相比。与单独使用伊马替尼或尼洛替尼相比，BCR-ABL 小干扰 RNA 联合伊马替尼或尼洛替尼治疗可显著增加 T315I 细胞的增殖抑制和凋亡诱导（P<0.0001）。此外，BCR-ABL 小干扰 RNA 联合伊马替尼或尼洛替尼显著（P<0.01）逆转了突变细胞对多药耐药基因 1 依赖性耐药性。在 T315I 细胞中，尼洛替尼联合 BCR-ABL 小干扰 RNA 对细胞周期分布有强大的影响。
我们的数据表明，BCR-ABL 小干扰 RNA 沉默联合伊马替尼或尼洛替尼可能与针对酪氨酸激酶抑制剂敏感和耐药 BCR-ABL 细胞的附加抗白血病活性相关，可能是克服 BCR-ABL 突变的一种替代方法。
