Enhancing SHP-1 expression with 5-azacytidine may inhibit STAT3 activation and confer sensitivity in lestaurtinib (CEP-701)-resistant FLT3-ITD positive acute myeloid leukemia. Issue 1 (December 2015)

• Record Type: Journal Article
• Authors: Al-Jamal, Hamid; Mat Jusoh, Siti; Hassan, Rosline; Johan, Muhammad
• Is Part Of: BMC cancer. Volume 15:Issue 1(2015)
• Page Start: 1
• Page End: 11
• Publication Date: 2015-12
• Subjects: AML -- SHP-1 -- CEP-701 -- Resistance -- 5-Azacytidine -- STAT3; Cancer -- Periodicals; 616.994005
• DOI: 10.1186/s12885-015-1695-x
• Languages: English
• ISSNs: 1471-2407

Abstract

Abstract Background Tumor-suppressor genes are inactivated by methylation in several cancers including acute myeloid leukemia (AML). Src homology-2 (SH2)-containing protein-tyrosine phosphatase 1(SHP-1) is a negative regulator of the JAK/STAT pathway. Transcriptional silencing ofSHP-1 plays a critical role in the development and progression of cancers through STAT3 activation. 5-Azacytidine (5-Aza) is a DNA methyltransferase inhibitor that causes DNA demethylation resulting in re-expression of silencedSHP-1 . Lestaurtinib (CEP-701) is a multi-targeted tyrosine kinase inhibitor that potently inhibitsFLT3 tyrosine kinase and induces hematological remission in AML patients harboring the internal tandem duplication of theFLT3 gene (FLT3 -ITD). However, the majority of patients in clinical trials developed resistance to CEP-701. Therefore, the aim of this study, was to assess the effect of re-expression ofSHP-1 on sensitivity to CEP-701 in resistant AML cells. Methods Resistant cells harboring theFLT3 -ITD were developed by overexposure of MV4-11 to CEP-701, and the effects of 5-Aza treatment were investigated. Apoptosis and cytotoxicity of CEP-701 were determined using Annexin V and MTS assays, respectively. Gene expression was performed by quantitative real-time PCR. STATs activity was examined by western blotting and the methylation profile ofSHP-1 was studied using MS-PCR and pyrosequencing analysis. Repeated-measures ANOVA and Kruskal–Wallis tests were used for statistical analysis. Results The cytotoxic dose of CEP-701 on resistant cells was significantly higher in comparison with parental and MV4-11R-cep + 5-Aza cells (p = 0.004). The resistant cells showed a significant higher viability and lower apoptosis compared with other cells (p < 0.001). Expression ofSHP-1 was 7-fold higher in MV4-11R-cep + 5-Aza cells compared to parental and resistant cells (p = 0.011). STAT3 was activated in resistant cells. Methylation ofSHP-1 was significantly decreased in MV4-11R-cep + 5-Aza cells (p = 0.002). Conclusions The restoration ofSHP-1 expression induces sensitivity towards CEP-701 and could serve as a target in the treatment of AML. Our findings support the hypothesis that, the tumor-suppressor effect ofSHP-1 is lost due to epigenetic silencing and its re-expression might play an important role in re-inducing sensitivity to TKIs. Thus, SHP-1 is a plausible candidate for a role in the development of CEP-701 resistance inFLT3-ITD+ AML patients.