Monocyte-macrophage differentiation of acute myeloid leukemia cell lines by small molecules identified through interrogation of the Connectivity Map database

Abstract

The transcription factor C/EBPa is required for granulocytic differentiation of normal myeloid progenitors and is frequently inactivated in acute myeloid leukemia (AML) cells. Ectopic expression of C/EBPa in AML cells suppresses proliferation and induces differentiation suggesting that restoring C/EBPa expression/activity in AML cells could be therapeutically useful. Unfortunately, current approaches of gene or protein delivery in leukemic cells are unsatisfactory. However, "drug repurposing" is becoming a very attractive strategy to identify potential new uses for existing drugs. In this study, we assessed the biological effects of candidate C/EBPa-mimetics identified by interrogation of the Connectivity Map database. We found that amantadine, an antiviral and anti-Parkinson agent, induced a monocyte-macrophage-like differentiation of HL60, U937, Kasumi-1 myeloid leukemia cell lines, as indicated by morphology and differentiation antigen expression, when used in combination with suboptimal concentration of all trans retinoic acid (ATRA) or Vit D3. The effect of amantadine depends, in part, on increased activity of the vitamin D receptor (VDR), since it induced VDR expression and amantadine-dependent monocyte-macrophage differentiation of HL60 cells was blocked by expression of dominant-negative VDR. These results reveal a new function for amantadine and support the concept that screening of the Connectivity Map database can identify small molecules that mimic the effect of transcription factors required for myelo-monocytic differentiation.

Identification of drugs for leukaemia differentiation therapy by network pharmacology

“…and HL60 cell lines together with the fact that our framework is built on a leukaemia cell line, we decided to implement ssCMAP for cell-line specific results (see Materials and Methods). This is also supported by previous studies on AML using CMAP, which query CMAP at the HL60 cell line level 27,35 . The input to ssCMAP was each TF-driven network or the combined networks of best combinations (see Table 2).…”

“…A few other studies investigating drugs that induce leukaemia differentiation are based on a priori knowledge, focusing particularly on the CEBPα transcription factor which directs granulocytic differentiation 67 . In these cases, a CEBPα-induced gene expression signature from the chronic myeloid leukaemia (CML) cell line K562 was used to query CMAP and predict drugs that mimic this gene expression signature 26,27 . These approaches recovered different drugs from the ones we identified, possibly due to (1) the use of microarray data generated in a different cell line for signature derivation, (2) the use of the network of only one TF (CEBPα) and (3) the use of the original GSEA-like method to query CMAP 20 .…”

“…CMAP has previously been used for drug repurposing 21,22,23 . By using input signatures specific to leukaemia cells or TFs as the input to CMAP, other studies have identified drugs which eliminate leukaemia cells, induce their differentiation or the loss of self-renewal 24,25,26,27 . Here we extend this approach at the network level, using Mogrify-identified TFs and their networks as the input signature for CMAP, to identify differentiation-inducing drugs.…”

The MEK5/ERK5 signalling pathway in cancer: a promising novel therapeutic target

“…These progenitor cells fail to differentiate into mature cells, including granulocytes or macrophages, and, as a result, accumulate inside bone marrow [64]. For the current treatment of leukaemia, particularly for acute myeloid leukaemia (AML) and acute lymphocytic leukaemia (ALL), two main strategies have been the focus of current research.…”

“…For the current treatment of leukaemia, particularly for acute myeloid leukaemia (AML) and acute lymphocytic leukaemia (ALL), two main strategies have been the focus of current research. These strategies aim to limit cell proliferation and promote either cell differentiation (differentiation therapies) or apoptosis of the transformed progenitor cells (proapoptotic therapies) [64]. The importance of understanding the signalling circuitry in leukaemia arises from the inefficiency of treatment options in current treatment regimens that rarely lead to patient survival.…”