Decitabine and guadecitabine are hypomethylating agents (HMAs) that exert inhibitory effects against cancer cells. This includes stimulation of anti-tumor immunity in acute myeloid leukemia (AML) and myelodysplastic syndromes (MDS) patients. Treatment of AML and MDS patients with the HMAs confers upregulation of cancer/testis antigens (CTAs) expression including the highly immunogenic CTA NY-ESO-1. This leads to activation of CD4+ and CD8+ T cells for elimination of cancer cells, and it establishes the feasibility to combine cancer vaccine with HMAs to enhance vaccine immunogenicity. Moreover, decitabine and guadecitabine induce the expression of immune checkpoint molecules in AML cells. In this review, the accumulating knowledge on the immunopotentiating properties of decitabine and guadecitabine in AML and MDS patients are presented and discussed. In summary, combination of decitabine or guadecitabine with NY-ESO-1 vaccine enhances vaccine immunogenicity in AML patients. T cells from AML patients stimulated with dendritic cell (DC)/AML fusion vaccine and guadecitabine display increased capacity to lyse AML cells. Moreover, decitabine enhances NK cell-mediated cytotoxicity or CD123-specific chimeric antigen receptor-engineered T cells antileukemic activities against AML. Furthermore, combination of either HMAs with immune checkpoint blockade (ICB) therapy may circumvent their resistance. Finally, clinical trials of either HMAs combined with cancer vaccines, NK cell infusion or ICB therapy in relapsed/refractory AML and high-risk MDS patients are currently underway, highlighting the promising efficacy of HMAs and immunotherapy synergy against these malignancies.
Introduction: Current prognostic markers have improved survival prediction, however, it has not
advanced treatment strategies. Gene expression profiling may identify biological markers suitable as
therapeutic targets. Leukaemia stem cell is associated with adverse outcome, however, its biological
characteristics are still being investigated. We observed higher in vitro cell viability in acute myeloid
leukaemia (AML) samples with poor prognosis, which may be stem cell related. Objective: The
objective of this study was to profile highly expressed genes in an AML sample of poor prognosis/high
viability and compare with a sample of good prognosis/low viability. Method: Subtractive hybridization
was performed on two AML samples with high blast counts (>80%), a poor prognosis, PP (disease free
survival, DFS12 months) sample. The PP sample had
higher CD34+ counts (73% vs 46%) and higher cell viability than the GP sample. cDNA libraries were
subsequently cloned and sequenced. Results: cDNA subtracted from the PP samples was identified
as genes active during fetal/embryonic development (LCOR, CNOT1, ORMDL1), HOX- related genes
(HOXA3, PBX3, SF3B1), hematopoiesis (SELL, IL-3RA) and aerobic glycolysis/hypoxia (PGK1,
HIGD1A) -associated genes. Majority of GP clones isolated contained genes involved in oxidative
phosphorylation, OXPHOS (COXs, ATPs, MTND4 and MTRNR2), protein synthesis (including
ribosomal proteins, initiating and elongation factors), chromatin remodeling (H2AFZ, PTMA), cell
motility (MALAT1, CALM2, TMSB4X), and mitochondria (HSPA9, MPO) genes. Conclusion: Thus,
the PP sample exhibited stem cell-like features while the GP sample showed cells at a high level of cell
activity. These genes are potential prognostic markers and targets for therapy.