Identification and functional signature of genes regulated by structurally different ABL kinase inhibitors

Abstract

Dasatinib is an ATP-competitive, multi-targeted SRC and ABL kinase inhibitor that can bind BCR-ABL in both the active and inactive conformations. From a clinical standpoint, dasatinib is particularly attractive because it has been shown to induce hematologic and cytogenetic responses in imatinib-resistant chronic myeloid leukemia patients. The fact because the combination of imatinib and dasatinib shows the additive/synergistic growth inhibition on wild-type p210 BCR-ABL-expressing cells, we reasoned that these ABL kinase inhibitors might induce the different molecular pathways. To address this question, we used DNA microarrays to identify genes whose transcription was altered by imatinib and dasatinib. K562 cells were cultured with imatinib or dasatinib for 16 h, and gene expression data were obtained from three independent microarray hybridizations. Almost all of the imatinib-and dasatinib-responsive genes appeared to be similarly increased or decreased in K562 cells; however, small subsets of genes were identified as selectively altered expression by either imatinib or dasatinib. The distinct genes that are selectively modulated by dasatinib are cyclin-dependent kinase 2 (CDK2) and CDK8, which had a maximal reduction of o5-fold in microarray screen. To assess the functional importance of dasatinib regulated genes, we used RNA interference to determine whether reduction of CDK2 and CDK8 affected the growth inhibition. K562 and TF-1BCR-ABL cells, pretreated with CDK2 or CDK8 small interfering RNA, showed additive growth inhibition with imatinib, but not with dasatinib. These findings demonstrate that the additive/ synergistic growth inhibition by imatinib and dasatinib may be mediated in part by CDK2 and CDK8.

Tyrosine kinase inhibition in diffuse large B-cell lymphoma: molecular basis for antitumor activity and drug resistance of dasatinib

“…K562 was used as a positive control as a number of cell cycle proteins were downregulated by dasatinib in this BCR-ABL-containing cell line. 22 Downregulation of c-Myc, cyclin-dependent kinase 2 (CDK2), CDK4, CDK6, cyclin D2, cyclin D3, CDK3 and CDK8 was detected in LY10 cells after 72 h of dasatinib treatment (Figure 4, LY10). However, this downregulation was not detected in LY7, LY18 and LY3 cells (Figure 4 and see discussion).…”

Chromosomal instability determines taxane response

“…Microarray profiling of drug-induced gene expression changes has identified shared intracellular pathways through which disparate small molecules exert their cytotoxic activity (11)(12)(13). MTS drugs such as taxanes and epothilones, which compete for a similar microtubule-interacting region, initiate similar gene expression changes, suggesting that disruption of the microtubule network induces a characteristic gene expression response (14).…”

BCR‐ABL1 tyrosine kinase sustained MECOM expression in chronic myeloid leukaemia

“…Regulation of mRNA expression is rapid, suggesting it is a direct response to inhibition of tyrosine kinase-mediated signalling from the BCR-ABL1 protein. Several studies have previously identified many potential BCR-ABL1 target genes but MECOM was not described (Håkansson et al, 2008;Nunoda et al, 2007;Bianchini et al, 2007). This study represents the first report of a signal transduction pathway that regulates MECOM gene expression.…”