Upregulation of CD11b and CD86 through LSD1 inhibition promotes myeloid differentiation and suppresses cell proliferation in human monocytic leukemia cells

Abstract

LSD1 (Lysine Specific Demethylase1)/KDM1A (Lysine Demethylase 1A), a flavin adenine dinucleotide (FAD)-dependent histone H3K4/K9 demethylase, sustains oncogenic potential of leukemia stem cells in primary human leukemia cells. However, the pro-differentiation and anti-proliferation effects of LSD1 inhibition in acute myeloid leukemia (AML) are not yet fully understood. Here, we report that small hairpin RNA (shRNA) mediated LSD1 inhibition causes a remarkable transcriptional activation of myeloid lineage marker genes (CD11b/ITGAM and CD86), reduction of cell proliferation and decrease of clonogenic ability of human AML cells. Cell surface expression of CD11b and CD86 is significantly and dynamically increased in human AML cells upon sustained LSD1 inhibition. Chromatin immunoprecipitation and quantitative PCR (ChIP-qPCR) analyses of histone marks revealed that there is a specific increase of H3K4me2 modification and an accompanied increase of H3K4me3 modification at the respective CD11b and CD86 promoter region, whereas the global H3K4me2 level remains constant. Consistently, inhibition of LSD1 in vivo significantly blocks tumor growth and induces a prominent increase of CD11b and CD86. Taken together, our results demonstrate the anti-tumor properties of LSD1 inhibition on human AML cell line and mouse xenograft model. Our findings provide mechanistic insights into the LSD1 functions in controlling both differentiation and proliferation in AML.

Lysine-Specific Demethylase 1A as a Promising Target in Acute Myeloid Leukemia

“…Fang et al showed that shRNA-mediated inhibition of LSD1 in AML cells, contrary to what had been previously described in the normal hematopoietic system, causes a remarkable transcriptional activation of myeloid lineage genes (CD11b/ITGAM and CD86), along with a reduction of AML cell proliferation and clonogenic ability. Chromatin immunoprecipitation analyses revealed that LSD1 silencing is accompanied by a specific increase of H3K4me2 and H3K4me3 modifications specifically at the promoter regions of CD11b and CD86, whereas global H3K4me2 levels remain constant, as previously reported ( 61 ). Cusan et al performed a comparative assessment of chromatin dynamics during the treatment of MLL-AF9-driven murine leukemia and MLL-rearranged patient-derived xenografts with differentiation-inducing epigenetic therapies targeting LSD1 and DOT1L.…”

Tuning mTORC1 activity dictates the response of acute myeloid leukemia to LSD1 inhibition

“…Next, we investigated whether DDP38003 was efficiently inhibiting LSD1 in resistant AML. Indeed, genes reported to be directly repressed by LSD1 12 , 25 were upregulated post-DDP38003 treatment in both resistant THP-1 and sensitive KASUMI-1 cells confirming efficient LSD1 inhibition ( Online Supplementary Figure S1C ). We then inquired whether such differential responsiveness of AML cells correlates with the basal level of LSD1.…”

Diallyl disulfide down‐regulates calreticulin and promotes C/EBPα expression in differentiation of human leukaemia cells

“…We performed similar analyses for CD11b expression (Figure C). CD11b, also known as cluster of differentiation 11b molecule, is expressed on the surface of numerous leucocytes involved in the innate immune system, including monocytes, granulocytes, macrophages, and natural killer cells . We found that while control cells showed low CD11b expression (1.00%), CRT siRNA significantly increased CD11b expression (7.67%).…”