The Mechanism Of Small Molecule Drug Suppressing Acute Lymphoblastic Leukemia Cell Proliferation

Objective: T-cell acute lymphoblastic leukaemia(T-ALL) is a haematological malignancy with a poor overall prognosis with a relapse rate up to 25%, which lack non-cytotoxic targeted therapeutic drugs. GSK-J4, a novel small molecule drug, is reported in treatment of some solid tumors’ growth by targeting JMJD3 activity. However, little is known about this small molecule drug in T-ALL treatment. Here, we investigated the possible role and mechanism of GSK-J4 in T-ALL cells.Methods: Four kinds of small molecule drugs, including Scopoletin,Gambogic acid, Fisetin and GSK-J4, were used to treat T-ALL Jurkat cells and 293 T cells. The cell growth of these cells was identified by CCK-8 assay,and AnnexinV assay was used to test cell apoptosis. Real time RT-PCR and Western Blot were used to detect the gene and protein expression of H3K27Me3, Tal1 and GATA3 in Jurkat cells treated with GSK-J4. The stable Jurkat-siTal1 and Jurkat-T1 cells were established by transfecting T-ALL Jurkat cells with lentiviral vectors to knock-down or overexpress Tal1 gene expression. Jurkat cells transfected with negative control siRNAs for Tal1knock-down(Jurkat-mock1) and over-expression(Jurkat-mock2) were served as the control cells. The effect of Tal1 on the growth of the cells was assessed by using CCK-8 assays.Results: The results of CCK-8 assays demonstrated that 0-7000 nM concentration of Scopoletin promoted Jurkats cell growth. The IC50 of Gambogic acid to Jurkat and 293 T cells were 150 nM and 150 n M at 48 hour respectively. The IC50 of Fisetin to Jurkat and 293 T cells were 10 μM and 5μM at 48 hour respectively. And the best inhibition concentration of GSK-J4 for Jurkat cells was 7 μM at 24 hour,but without effect on 293 T cells. The results of flow cytometry demonstrated that the cell apoptosis of Jurkat cells was promoted with 1.5-10 μM GSK-J4 treated at 24 hour. The data of real-time RT-PCR, Western Blot and CCK-8 demonstrated the expression of H3K27me3 was promoted while that of Tal1 were inhibited in Jurkat cells with 1.5-10 μM GSK-J4 treated at 24 hour.Conclusion: GSK-J4, the small molecule drug, specifically suppresses T-ALL cell growth by modifying H3K27me3 and Tal1 expression.