Selective expression of the transcription elongation factor Eleven Nineteen Lysine-rich Leukemia 3 (ELL3) in actiavted B lymphocytes drives rapid B cell proliferation

To identify novel targets of the transcriptional repressor that functions to extinguish the B cell phenotype during terminal plasma cell differentiation, we assessed PRDM1 bound sequences through ChIP-Seq. We prepared PRDM1-enriched chromatin from two PRDM1 positive mutiple myeloma cell lines, U266 and NCI-H929. At least 5 PRDM1- or IgG enrichments were performed per cell line and pooled into the two respective conditions per cell line. The U226 and NCI-H929 revealed respectively, 574 and 2887 association peaks were indentified per cell line. Both cell lines displayed an intense peak at the ELL3 loci, suggesting PRDM1 association. This was validated by ChIP followed by qPCR, confirming PRDM1 association. Examination of PRDM1 binding sites in two Multiple Myeloma cell lines