Background. AML (acute myeloid leukemia) is a common hematological malignancy in children with poor treatment effects and poor prognosis. Recent studies have shown that as a novel BRD4 (bromodomain containing 4) PROTACs (proteolysis targeting chimeras) degrader, GNE-987 can slow down the growth of various tumors and increase apoptosis, with promising clinical prospects. However, the function and molecular mechanism of GNE-987 in AML remain unclear. This study is aimed at investigating the therapeutic effect of GNE-987 on AML and its underlying mechanism. Methods. The association between BRD4 and AML was assessed by studying public databases. After GNE-987 was added to AML cells, cell proliferation slowed down, the cycle was disturbed, and apoptosis increased. Western blotting was used to detect BRD2 (bromodomain containing 2), BRD3 (bromodomain containing 3), BRD4, and PARP (poly ADP-ribose polymerase) proteins. The effect of GNE-987 on AML cells was analyzed in vivo. RNA-seq (RNA sequencing) and ChIP-seq (chromatin immunoprecipitation sequencing) validated the function and molecular pathways of GNE-987 in processing AML. Results. BRD4 expression was significantly elevated in pediatric AML samples compared with healthy donors. GNE-987 inhibited AML cell proliferation by inhibiting the cell cycle and inducing apoptosis. BRD2, BRD3, and BRD4 were consistent with decreased VHL (Von Hippel Lindau) expression in AML cells. In an AML xenograft model, GNE-987 significantly reduced the hepatosplenic infiltration of leukemia cells and increased the mouse survival time. Based on analysis of RNA-seq and ChIP-seq analyses, GNE-987 could target multiple SE- (super-enhancer-) related genes, including LYL1 (lymphoblastic leukemia 1), to inhibit AML. Conclusions. GNE-987 had strong antitumor activity in AML. GNE-987 could effectively inhibit the expression of SE-related oncogenes including LYL1 in AML. Our results suggested that GNE-987 had broad prospects in the treatment of AML.

Background: Haploidentical hematopoietic stem cell transplantation (haplo-HSCT) based on granulocyte colony-stimulating factor plus anti-thymocyte regimens (‘Beijing Protocol’) provides a salvage treatment for patients of acquired severe aplastic anemia (SAA) in China. However, graft- versus-host disease (GVHD) is a major impediment of haplo-HSCT due to human leukocyte antigen disparity. Recently, haplo-HSCT combined with umbilical cord blood (UCB) (haplo-cord HSCT) is performed in clinical trials to potentially reduce the risk of severe GVHD. Nevertheless, studies comparing GVHD in pediatric patients receiving haplo and haplo-cord HSCT for SAA are limited. Objective: The objective of this study was to investigate the impact of UCB co-infusion on GVHD in pediatric patients receiving haplo-HSCT for SAA. Design: We conducted a retrospective study of 91 consecutive SAA children undergoing haploidentical transplantation based on the ‘Beijing Protocol’ with or without co-infusion of UCB in our center. Methods: All patients received uniform non-myeloablative conditioning and GVHD prophylaxis. We compared baseline characteristics and transplant outcomes between the haplo ( n = 35) and haplo-cord ( n = 56) recipients. Results: All 91 patients achieved hematopoietic recovery from haploidentical donors, with a higher incidence of peri-engraftment syndrome observed with the haplo-cord group as compared with the haplo group (75.0% versus 48.6%, p = 0.029). Notably, the haplo-cord group showed a lower incidence of II–IV acute GVHD (aGVHD) than the haplo group (16.1% versus 42.9%, p = 0.002). Observed incidences of chronic GVHD (cGVHD) and moderate to severe cGVHD in the haplo-cord group were also lower than that in the haplo group (25.6% versus 51.3%, p = 0.019; 16.2% versus 41.3%, p = 0.016, respectively). Haplo-cord HSCT was identified as the only factor associated with a lower incidence of II–IV aGVHD and cGVHD in multivariate analysis. However, no differences were observed between the two groups for infections and survival outcomes. Conclusion: Our data indicated that co-infusion of UCB in ‘Beijing Protocol’-based haplo-HSCT may be effective for reducing the risk of severe GVHD in SAA children.

Background: Acute myeloid leukemia (AML) is a common hematological malignancy in children, with poor treatment effect and poor prognosis. Recent studies have shown that bromodomain and terminal protein inhibitors are promising antitumor drugs. As a new type of BRD4 PROTAC degradation agent, GNE-987 can slow down the growth rate of a variety of tumors and cause apoptosis, which has broad clinical prospects. However, the role of GNE-987 in AML is unclear. This study aims to explore the therapeutic effect of GNE-987 in AML and its underlying mechanism.Methods: By studying public databases, the prognostic significance of BRD4 and the correlation between AML were evaluated, and the relationship between BRD4 and the overall survival rate of AML patients was also analyzed. After adding GNE-987 to the AML cell line, cell proliferation slowed down, cycle disorder, and apoptosis increased. In the cells treated with GNE-987, western-blotting was used to detect BRD2, BRD3, BRD4 and PARP proteins. The effect of GNE-987 on AML cells was analyzed in vivo. RNA-seq and chromatin immunoprecipitation sequencing (ChIP-seq) confirmed the function and molecular pathway of GNE-987 in processing AML. Results: Compared with healthy donors, the expression of BRD4 in children's AML samples was higher than that of healthy donors. The high expression of BRD4 indicates a poor prognosis. GNE-987 inhibits AML cell proliferation by inhibiting the cell cycle and inducing apoptosis. BRD2, BRD3 and BRD4 are consistent with the decreased expression of VHL in AML cells. Compared with JQ1 and ARV-825, GNE-987 has a lower IC50 in AML cells. In the AML xenograft model, GNE-987 significantly reduced the liver and spleen infiltration of leukemia cells, increased the survival time of mice, and caused BRD4, Ki67 dysregulation and caspase3 activation. According to the analysis of RNA-seq and ChIP-seq, GNE-987 can inhibit AML by targeting numerous super-enhancers.Conclusions: GNE-987 has strong anti-tumor activity in AML cell lines and primary child AML samples. GNE-987 works by degrading the BET protein, thereby effectively inhibiting the expression of super enhancers and related oncogenes (such as LYL1). These results indicate that GNE-987 has very broad prospects for the treatment of AML.