Determining the efficacy of menin and CDK7 inhibitors on AML cell lines
Acute myeloid leukemia (AML) is the most common type of leukemia in adults, with a 5-year survival rate of 31.7%. Despite AML therapy improvements, 40%–60% of patients above 60 years-old, relapse. AML is characterized by an abnormal number of immature myoblasts that leads to a decrease in white blood cells and are characterized by genetic alterations which drive oncogenesis. For instance, translocations of the KMT2A gene result in an oncogenic fusion protein that activates genes to block differentiation and promote proliferation. The KMT2A gene can have many fusion partners, with more than 70 partners having been identified. This fusion protein recruits many proteins, such as Menin and CDK9, that are essential for leukogenic transcription. CDK7 is a key part of the CDK-activating complex that drives the cell cycle and regulates transcription. It phosphorylates CDK9 and the CTD domain of RNA polymerase II to promote transcription of genes that prevent apoptosis. A reversible CDK7 inhibitor, TGN-1062, has been developed by our laboratory, but has yet to be tested on AML cell lines. This study aims to test if Revumenib, a Menin inhibitor, can be used in combination with TGN-1062 to enhance the efficacy of AML treatment. To test the combination’s efficacy, AML cell lines (MOLM13, THP1, Kasumi-1) were treated with various concentrations of each agent or various combinations of the agents and cell viability assays, flow cytometry, and RT-PCR were performed. MOLM13 and THP1 cell lines have MLL-AF9 fusions and Kasumi-1 are a wildtype and used as a control. The RT-PCR results demonstrate that over a 4-day time course, single doses of TGN-1062 increase the expression of differentiation block genes and the combinations of the two agents are results are very comparable to the single dose of Revumenib. However, the flow cytometry results indicate over a 7-day experiment, TGN-1062 alone increases levels of differentiation, and the lower combination of TGN-1062 and Revumenib showed slightly higher levels of differentiation compared to the populations that received a single dose of Revumenib or TGN-1062. The synergy observed between the 2 agents is marginal and further experiments with different dosing times or repeat dosing and further evaluation of CDK9 expression and phosphorylation over an extended time course is needed to better understand the effects of the combination of TGN-1062 and Revumenib.
