Fms-like tyrosine kinase 3-internal tandem duplications epigenetically activates checkpoint kinase 1 in acute myeloid leukemia cells

Yudong Zhang,Lingli Yuan

doi:10.1038/s41598-021-92566-5

Abstract

It is not clear how Fms-like tyrosine kinase 3-internal tandem duplications (FLT3-ITD) regulates checkpoint kinase 1 (CHK1) in acute myeloid leukemia (AML). In this study, we investigated the regulatory effect of FLT3-ITD on CHK1. Our results showed that CHK1 was highly expressed in FLT3-ITD positive AML. The overall survival rate and disease-free survival rate of AML patients with high CHK1 level were lower than those of patients with low CHK1 level. Mechanistically, FLT3-ITD recruited p300 to the CHK1 promoter and subsequently acetylated H3K27, thereby enhancing the transcription of CHK1. Interfering with the expression of CHK1 significantly inhibited the cell proliferation and induced cell apoptosis in FLT3-ITD positive MV4-11 cells. In addition, CHK1 knockdown promoted the sensitivity of MV4-11 cells to the epigenetic inhibitors JQ1 and C646. This study discovers a new therapeutic target for FLT3-ITD + AML and provided evidence for the combination of epigenetic inhibitors for AML treatment.

Highlights

It is not clear how Fms-like tyrosine kinase 3-internal tandem duplications (FLT3-internal tandem replication (ITD)) regulates checkpoint kinase 1 (CHK1) in acute myeloid leukemia (AML)
By Pearson correlation analysis, we found that the expression of CHK1 in patients with AML was positively correlated with the level of FMS-like tyrosine kinase-3 gene (FLT3)-ITD (r = 0.512, p < 0.001, Fig. 2C)
In the AML cell line, we found that the expression of CHK1 in FLT3-ITD+ AML cells MV4-11 was significantly higher than other FLT3-ITD negative AML cells (Fig. 2D)

Summary

Materials and methods

56 patients with non-hematological tumor diseases who underwent bone marrow aspiration were included as a control group, including 30 males and 26 females (22–70 years, with an average of 52.6 ± 14.2 years). To determine the luciferase activity, 100 ng of blank pcDNA3 vector or pcDNA3 vector containing FLT3-ITD cDNA and 400 ng LUC reporter vector were co-transfected into HEK293T cells for 48 h in a 24-well plate. The cells transfected with pRL-TK Renilla luciferase reporter gene vector (Promega) were used as a control. Cell proliferation was evaluated using the CCK-8 kit (Beyotime Biotechnology, Shanghai, China) according to the manufacturer’s instructions. The cells were mixed gently with labeling solution (10 μl 10 × Binding Buffer, 5 μl annexin V-FITC, 85 μl distilled water), and incubated for 15 min Scientific Reports | (2021) 11:13236 |.

Result

Findings

Discussion