RPS6KA1 is a histone acetylation-related oncoprotein in acute myeloid leukemia which is targeted by afzelin.

BACKGROUND: Histone acetylation plays a critical role in the progression of acute myeloid leukemia (AML). This study aimed to explore the prognostic significance and biological implications of histone acetylation-related genes in AML and to identify potential oncoproteins and therapeutic compounds. METHODS: Genes associated with AML and histone acetylation were identified using the TCGA-LAML and IMEx Interactome databases. A histone acetylation-related risk model was developed using the least absolute shrinkage and selection operator method. The prognostic value of the model was evaluated through Kaplan-Meier survival analysis, time-dependent receiver operating characteristic curve, univariate and multivariate Cox regression, and nomogram calibration. Key genes were identified using random forest, support vector machine, and multivariate Cox analysis. Molecular docking was employed to assess the binding affinity between ribosomal protein S6 kinase A1 (RPS6KA1) and potential compounds. Furthermore, the effects of RPS6KA1 and afzelin on the malignant behaviors and downstream pathways of AML cells were validated through in vitro experiments. RESULTS: A risk model composed of 6 genes, including HDAC6, CREB3, KLF13, GOLGA2, RPS6KA1 and ZMIZ2, was established, demonstrating strong prognostic predictive capability. Among these, RPS6KA1 emerged as a key risk factor linked to histone acetylation status in AML. Elevated RPS6KA1 expression was observed in AML samples and was associated with poor prognosis. RPS6KA1 knockdown suppressed AML cell proliferation, migration, and invasion, induced G0/G1 phase arrest, and promoted apoptosis. Additionally, RPS6KA1 was identified as a potential target for afzelin, which exhibited anti-AML activity by inactivating RPS6KA1. CONCLUSION: Histone acetylation status is closely associated with AML patient prognosis. RPS6KA1 acts as an oncoprotein in AML, facilitating disease progression. Afzelin may represent a novel therapeutic agent for AML by targeting RPS6KA1, which requires validation by clinical trials.

High-resolution mass spectrometry-based approach for the identification and profiling of the metabolites of taletrectinib formed in liver microsomes.

Taletrectinib is a potent, orally active, and selective ROS1/NTRK kinase inhibitor. The aim of this study was to study the metabolism of taletrectinib in rat, dog, and human liver microsomes. The biotransformation of taletrectinib was carried out using rat, dog, and human liver microsomes supplemented with nicotinamide adenine dinucleotide phosphate tetrasodium salt (NADPH) and uridine diphosphate glucuronic acid (UDPGA). The microsomal incubations were conducted at 37°C for 60 min. The formed metabolites were identified by ultrahigh performance liquid chromatography coupled to high-resolution tandem mass spectrometry (UHPLC-HRMS) using electrospray ionization in the positive ion mode. They were identified by accurate masses and MS/MS spectra and based on their fragmentation pathways. With UHPLC-HRMS, a total of 10 metabolites including one glucuronide conjugate (M7) were structurally identified. M9 and M10 were unambiguously identified as taletrectinib alcohol and taletrectinib ketone, respectively, using reference standards. The phase I metabolic pathways of taletrectinib involved N-dealkylation, O-dealkylation, oxidative deamination, and oxygenation; the phase II metabolic pathways referred to glucuronidation. The current study investigated the in vitro metabolic fate of taletrectinib in animals and human species, which would bring us considerable benefits for the subsequent studies focusing on the pharmacological effect and toxicity of this drug.

[Establishment of a Xenografted Acute Myeloid Leukemia Model by using Zebrafish].

Objectve: To investigate the feasibility of establishing xenografted leukemia model by zebrafish, so as to provide the more direct model in vitro and experimental evidence for study of acute myeloid leukemia and screening of the drugs for targeting therapy. METHODS: Acute myeloid leukemia cell line KG-1a was labeled with red fluorescent dye-MitoRed, then the labeled cells were injected into the yolk sac of zebrafish embryos. Morphological observation, cell count and histopathological detection were used to analyse the infiltration and metastasis of KG-1a cells in zebrafish. RESULTS: KG1a cells could proliferate and gradually spread to the entire abdominal cavity of the zebrafish after KG-1a cells were injected into the yolk sac during 1-7, the results of cell counting in vitro also proved a significant proliferation of KG-1a cells in zebrafish, suggesting that the implanted leukemia stem cells could survive, proliferate and spread in zebrafish. Further study showed that the implanted cells could be transfered to the liver of zebrafish, these cells displayed the signature of KG-1a cells by hematoxylin-eosin(HE) staining. CONCLUSIONS: Human acute myeloid leukemia cells KG1a can survive, proliferate and migrate in zebrafish, suggesting xenografted leukemia model of zebrafish has been successfully established. This model may be benefitcial for the study of acute myeloid leukemia and the screening of the drugs for targeting therapy of acute myeloid leukemia.

Low-dose arsenic trioxide combined with aclacinomycin A synergistically enhances the cytotoxic effect on human acute myelogenous leukemia cell lines by induction of apoptosis.

Acute myeloid leukemia (AML) is a common disorder in the elderly. Although remarkable progress has been made over recent decades, the outcome remains poor. Thus, the development of a more effective method to overcome this problem is necessary. In this study, we aimed to investigate the synergistic cytotoxic effect of low-dose arsenic trioxide (As2O3) combined with aclacinomycin A (ACM) on the human AML cell lines KG-1a and HL-60, and to clarify the underlying mechanism. Results showed that As2O3 combined with ACM exerted a synergistic cytotoxic effect by activation of the apoptosis pathway. Additionally, we found that the combination treatment decreased Bcl-2, c-IAP and XIAP expression but increased SMAC and caspase-3 expression more significantly than the single drug treatments. Furthermore, combination index (CI) values were < 1 in all matched combination groups. Additional evaluation of As2O3 combined with ACM as a potential therapeutic benefit for AML seems warranted.

[Effect of glycolytic inhibitor 3-BrPA on the proliferation and apoptosis of mouse splenic lymphocytes in mixed lymphocytes culture].

OBJECTIVE: To study the effect of glycolytic inhibitor 3-Bromopyruvate (3-BrPA) on the proliferation and apoptosis of mouse spleen lymphocytes and explore its mechanism. METHODS: An one-way mixed lymphocyte culture (MLC) system was established, including BALB/c mouse spleen cells (H-2d) as stimulator and C57BL/6 mouse spleen cells (H-2b) as responder. With treatment of 3-BrPA at different concentrations (0-200 µmol/L), lymphocyte proliferation capacity was detected by the CCK-8 method, the expression of CD3, CD4, and CD8 by flow cytometry, and the concentrations of cytokine interleukin (IL)-4 and interferon (IFN)-γ in the supernatant by ELISA. RESULTS: At a middle or high dose (over 20 µmol/L), 3-BrPA displayed a dose-dependent inhibitory effect on lymphocyte proliferation in the MLC system. The 50% inhibitory concentration (IC50) were 48.6, 41.2, and 41.9 µmol/L after 24, 36, and 48 h culture, respectively. With treatment of 50 µmol/L 3-BrPA, the IFN-γ level [(164.25 ± 20.14) ng/L] was significantly lower, compared with control [(277.61 ± 18.46) ng/L]. The IL-4 level [(31.06 ± 6.06) ng/L] was significantly higher, compared with control [(28.64 ± 3.97) ng/L]. Consequently, the IFN-γ/IL-4 ratio decreased significantly. CONCLUSION: These results indicate that 3-BrPA had a significant inhibitory effect on the proliferation of mouse spleen lymphocytes cultured in MLC system, accompanied with the Th2-biased secretion of cytokines.

[Effects of recombinant human interleukin 11 on hematological malignancy after allogeneic hematopoietic cell transplantation].

OBJECTIVE: To investigate the effects of recombinant human interleukin 11 (rhIL-11) on hematological malignancy after allogeneic hematopoietic stem cell transplantation (allo-HSCT). METHODS: A total of 48 patients with hematological malignancy from January 2006 to June 2010 were alternately enrolled into a prospective randomized study. And they were assigned into the control and rhIL-11 injection groups. Later the investigators compared two groups with regards to hematopoietic reconstitution, graft versus host disease (GVHD) classification, clinical recurrence rate and disease-free survival. RESULTS: With the therapy of rhIL-11, the absolute neutrophil counts recovering to 0.5 × 10(9)/L and platelet recovering to 20 × 10(9)/L were (15.1 ± 1.6) and (18.2 ± 3.3) days respectively. And they were significantly lower than those in control group [(16.1 ± 1.6) vs (22.4 ± 5.5) days, P = 0.032, 0.003]. The incidence of acute GVHD was surprisingly low in the study group (26.1% vs 50.0%, P = 0.048). There was no significant difference in chronic GVHD (36.8% vs 38.9%, P = 0.899) or relapse rate (5.1% vs 7.7%, P = 0.662) between two groups during a median follow-up period of 11.7 months. A trend of improved 3-year-disease-free survival was observed in the study group (65.4% vs 50.9%, P = 0.637). CONCLUSION: The application of rhIL-11 after allo-HSCT may accelerate both neutrophil and platelet engraftment and lower the occurrence of acute GVHD.