Associate Professor, Dickinson College, PA
Acute myeloid leukemia cell lines have served as model systems for studying cell proliferation, differentiation, programmed cell death, and leukemogenesis. In culture, AML cells can be induced to reverse their leukemic phenotype through genetic reprogramming by the activation of signaling systems that mediate changes in gene expression. Our lab has utilized a collection of AML cell lines representing various molecular subtypes to explore gene expression changes in response to the phorbol ester PMA, a diacylglycerol mimic that induces cell cycle arrest, myeloid differentiation toward macrophage-like cells, and eventual apoptosis. Using DNA microarrays and qRT-PCR validation, we have identified approximately 1200 significantly changing genes. We hypothesize that a subset of these transcriptional changes are required for reversal of the leukemic phenotype, overriding the oncogenic mutations that established the transformed state. To determine the crucial genes mediating this genetic reprogramming, we are overexpressing specific candidate genes and knocking out their functions using the CRISPR-Cas9 system. RNA-seq experiments comparing transcriptomes of wild type AML cells with overexpressor and knockout lines are in progress. Among the genes of particular interest are those encoding transcription factors, since changes in their expression levels potentially modify the expression of multiple target genes. Ultimately, we hope to identify new targets for the treatment of AML. Toward this goal, we have identified 25 genes that are overexpressed in a subset of AML patient samples, but are significantly down-regulated in AML cells as they revert to a “normal” myeloid cell phenotype and eventually undergo apoptosis.
Materials are under development.
Materials are under development.
