Differentiation of Acute Leukemia Cells Including Cells with MLL-AF4 Rearrangements Induced by Jiyuan Oridonin A.

Background: Chromosomal rearrangements involving the Mixed lineage leukemia (MLL) gene are observed in acute leukemia (AL) patients, which have poor prognosis, especially in infants. Hence, there is still a challenge to develop other effective agents to treat AL with MLL rearrangements (MLLr). MLL has been shown to rearrange with partner genes, of which the most frequently observed are AF4 and AF9. Moreover, AL is characterized by a differentiation blockage resulting in the accumulation of immature cells. An ent-kaurene diterpenoid compound, Jiyuan Oridonin A (JOA), has been shown to reduce the viability of AML cells by differentiation.

Methods: We aimed to evaluate the effect of JOA on the growth and differentiation of AL cells (SEM, JURKAT and MV4-11) including cells with MLLr-AF4 by cell proliferation assay, colony formation assay, cell cycle analysis, cell apoptosis analysis, measurement of cell surface antigens, cell morphology, mRNA-sequencing analysis, quantitative Real-time PCR and Western blotting analysis.

Results: Our findings demonstrated that the proliferation of AL cells including cells with MLLr-AF4 was significantly suppressed by JOA, which induced cell differentiation followed by G0/G1 cell cycle withdrawal. Moreover, JOA-mediated cell differentiation was likely due to activation of G-CSFR in MV4-11 cells.

Conclusion: Our results suggest that JOA may be considered a promising anti-leukemia compound to develop to surmount the differentiation block in AL patients.