Azacytidine Enhances Sensitivity Response to Imatinib in BCR/ABL positive CML Cell Line
Abstract
Azacytidine (5-Aza) is a chemotherapeutic drug that has been known to restore the expression of Tumour suppressor genes by de-methylation and shown clinical efficacy in Myelodysplastic syndrome (MDS) [1-3]. Currently, 5-Aza is being used in UK for the treatment of some adults with MDS, chronic myelocytic leukemia (CML) and acute myelocytic leukemia (AML) [4]. Majority of CML patients treated with imatinib, a BCR/ABL inhibitor would develop resistance under prolonged therapy. Signal transducer and activator of transcription 3 (STAT3) is an oncogenic transcription factor that is constitutively activated in various human cancers including hematological malignancies. Activation of STAT3 represents an important mechanism of imatinib resistant [5]. Methylation of SHP-1 is involved in the constitutive activation of STAT3 [6], and a low level of SHP-1 is not sufficient to inhibit activated STAT3 [7]. Epigenetic silencing of SHP-1 also plays a role in the development of resistance to imatinib in BCR/ABL positive CML cells [8].
Here we evaluated the expression of SHP-1 gene and its methylation status with sensitivity response of resistant CML cell lines to imatinib before and after treatment with 5-Aza. For this purpose, BCR/ABL positive CML cell lines, K562 and K562-R, an imatinib resistant cell lines were treated with 5-Aza. Cytotoxicity of imatinib and apoptosis were determined by MTS and Annexin-V, respectively. Gene expression analysis was detected by real time-PCR, STATs activity using Western blot and methylation status of SHP-1 gene by pyrosequencing analysis. There was a significant hypomethylation of SHP-1 gene in K562-R+5-Aza cells compared to other cells (p=0.003), Table 1.
Gene expression analysis indicates a significant re-expression of SHP-1 gene (p=0.001) after treatment of K562-R cells with 5-Aza (K562-R+5-Aza cells), Fig 1. Interestingly, the re-expression of SHP-1 in K562-R+5-Aza cell lines, was associated with STAT3 inactivation and higher sensitivity to imatinib. In conclusion, 5-Aza could enhance efficacy of imatinib on BCR/ABL CML cells through re-expression of SHP-1 gene and inhibition of STAT3 signaling that could be a new target in cancers treatment.
References
Kiziltepe, T., et al., 5-Azacytidine, a DNA methyltransferase inhibitor, induces ATR-mediated DNA double-strand break responses, apoptosis, and synergistic cytotoxicity with doxorubicin and bortezomib against multiple myeloma cells. Mol Cancer Ther, 2007. 6: p. 1718-1727.
Stresemann, C., et al., Modes of action of the DNA methyltransferase inhibitors azacytidine and decitabine. International journal of cancer Journal international du cancer, 2008. 123: p. 8-13.
Khan, H., et al., Role of DNA methylation in the pathogenesis and treatment of myelodysplastic syndromes. Seminars in hematology, 2013. 50: p. 16-37.
Lund, K., et al., DNMT inhibitors reverse a specific signature of aberrant promoter DNA methylation and associated gene silencing in AML. Genome biology, 2014. 15: p. 406.
Bewry, N.N., et al., Stat3 contributes to resistance toward BCR-ABL inhibitors in a bone marrow microenvironment model of drug resistance. Mol Cancer Ther, 2008. 7: p. 3169-3175.
Chim, C. S., et al., SOCS1 and SHP1 hypermethylation in multiple myeloma: implications for epigenetic activation of the Jak/STAT pathway. Blood, 2004. 103: p. 4630-4635.
Han, Y., et al., Restoration of shp1 expression by 5-AZA-2'-deoxycytidine is associated with downregulation of JAK3/STAT3 signaling in ALK-positive anaplastic large cell lymphoma. Leukemia, 2006. 20: p. 1602-1609.
Esposito, N., et al., SHP-1 expression accounts for resistance to imatinib treatment in Philadelphia chromosome-positive cells derived from patients with chronic myeloid leukemia. Blood, 2011. 118: p. 3634-3644.
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