RNAi-mediated silencing of MLL-AF9 reveals leukemia-associated downstream targets and processes

ABSTRACT: The translocation t(9;11)(p22;q23) leading to the leukemogenic fusion gene MLL-AF9 is a frequent translocation in infant acute myeloid leukemia (AML). This study aimed to identify genes and molecular processes downstream of MLL-AF9 (alias MLL-MLLT3) which could assist to develop new targeted therapies for such leukemia with unfavorable prognosis. In the AML cell line THP1 which harbors this t(9;11) translocation, endogenous MLL-AF9 was silenced via siRNA while ensuring specificity of the knockdown and its efficiency on functional protein level. The differential gene expression profile was validated for leukemia-association by gene set enrichment analysis of published gene sets from patient studies and MLL-AF9 overexpression studies and revealed 425 differentially expressed genes. Gene ontology analysis was consistent with a more differentiated state of MLL-AF9 depleted cells, with involvement of a wide range of downstream transcriptional regulators and with defined functional processes such as ribosomal biogenesis, chaperone binding, calcium homeostasis and estrogen response. Besides potential new therapeutic targets, the described transcription profile shaped by MLL-AF9 provides an information source into the molecular processes altered in MLL aberrant leukemia. 4 samples were analyzed, each corresponding to a pool of five independent replicate experiments. MLL-AF9 knockdown treatments are represented by 2 pooled samples employing two distinct siRNAs, each targeting MLL-AF9 breakpoint of THP1 cells. Control treatments are represented by 2 pooled samples employing two distinct non-targeting control siRNAs. siRNA-3 = siRNA-A in publication siRNA-4 = siRNA-B in publication

ORGANISM(S): Homo sapiens

SUBMITTER: Katrin Fleischmann 

PROVIDER: E-GEOD-36592 | biostudies-arrayexpress |

REPOSITORIES: biostudies-arrayexpress