BACKGROUND: T-cell lymphoblastic lymphoma/acute lymphoblastic leukemia (T-LBL/ALL) is an aggressive form of hematological malignancy associated with poor prognosis in adult patients. Histone deacetylases (HDACs) are aberrantly expressed in T-LBL/ALL and are considered potential therapeutic targets. Here, we investigated the antitumor effect of a novel HDAC inhibitor, chidamide, on T-LBL/ALL. METHODS: HDAC1, HDAC2 and HDAC3 levels in T-LBL/ALL cell lines and patient samples were compared with those in normal controls. Flow cytometry, transmission electron microscopy, and lactate dehydrogenase release assays were conducted in Jurkat and MOLT-4 cells to assess apoptosis and pyroptosis. A specific forkhead box O1 (FOXO1) inhibitor was used to rescue pyroptosis and upregulated gasdermin E (GSDME) expression caused by chidamide treatment. The role of the FOXO1 transcription factor was evaluated by dual-luciferase reporter and chromatin immunoprecipitation assays. The efficacy of chidamide in vivo was evaluated in a xenograft mouse. RESULTS: The expression of HDAC1, HDAC2 and HDAC3 was significantly upregulated in T-LBL/ALL. Cell viability was obviously inhibited after chidamide treatment. Pyroptosis, characterized by cell swelling, pore formation on the plasma membrane and lactate dehydrogenase leakage, was identified as a new mechanism of chidamide treatment. Chidamide triggered pyroptosis through caspase 3 activation and GSDME transcriptional upregulation. Chromatin immunoprecipitation assays confirmed that chidamide led to the increased transcription of GSDME through a more relaxed chromatin structure at the promoter and the upregulation of FOXO1 expression. Moreover, we identified the therapeutic effect of chidamide in vivo . CONCLUSIONS This study suggested that chidamide exerts an antitumor effect on T-LBL/ALL and promotes a more inflammatory form of cell death via the FOXO1/GSDME axis, which provides a novel choice of targeted therapy for patients with T-LBL/ALL.
Humans ; Pyroptosis/drug effects* ; Forkhead Box Protein O1/genetics* ; Aminopyridines/pharmacology* ; Animals ; Mice ; Benzamides/pharmacology* ; Cell Line, Tumor ; Precursor T-Cell Lymphoblastic Leukemia-Lymphoma/drug therapy* ; Phosphate-Binding Proteins/metabolism* ; Histone Deacetylase Inhibitors/pharmacology* ; Jurkat Cells ; Histone Deacetylases/metabolism* ; Apoptosis/drug effects* ; Gasdermins

BACKGROUND: Several studies have demonstrated the occurrence of secondary tumors as a rare but significant complication of chimeric antigen receptor T (CAR-T) cell therapy, underscoring the need for a detailed investigation. Given the limited variety of secondary tumor types reported to date, a comprehensive characterization of the various secondary tumors arising after CAR-T therapy is essential to understand the associated risks and to define the role of the immune microenvironment in malignant transformation. This study aims to characterize the immune microenvironment of a newly identified secondary tumor post-CAR-T therapy, to clarify its pathogenesis and potential therapeutic targets. METHODS: In this study, the bone marrow (BM) samples were collected by aspiration from the primary and secondary tumors before and after CD19 CAR-T treatment. The CD45 + BM cells were enriched with human CD45 microbeads. The CD45 + cells were then sent for 10× genomics single-cell RNA sequencing (scRNA-seq) to identify cell populations. The Cell Ranger pipeline and CellChat were used for detailed analysis. RESULTS: In this study, a rare type of secondary chronic myelomonocytic leukemia (CMML) were reported in a patient with diffuse large B-cell lymphoma (DLBCL) who had previously received CD19 CAR-T therapy. The scRNA-seq analysis revealed increased inflammatory cytokines, chemokines, and an immunosuppressive state of monocytes/macrophages, which may impair cytotoxic activity in both T and natural killer (NK) cells in secondary CMML before treatment. In contrast, their cytotoxicity was restored in secondary CMML after treatment. CONCLUSIONS This finding delineates a previously unrecognized type of secondary tumor, CMML, after CAR-T therapy and provide a framework for defining the immune microenvironment of secondary tumor occurrence after CAR-T therapy. In addition, the results provide a rationale for targeting macrophages to improve treatment strategies for CMML treatment.
Humans ; Lymphoma, Large B-Cell, Diffuse/therapy* ; Tumor Microenvironment/genetics* ; Antigens, CD19/metabolism* ; Leukemia, Myelomonocytic, Chronic/genetics* ; Immunotherapy, Adoptive/adverse effects* ; Male ; Single-Cell Analysis/methods* ; Female ; Sequence Analysis, RNA/methods* ; Receptors, Chimeric Antigen ; Middle Aged

OBJECTIVE: To investigate the role of nucleolin (NCL) in acute myeloid leukemia (AML) Kasumi-1 cells and its underlying mechanism. METHODS: The Kasumi-1 cells were infected with lentivirus carrying shRNA to downregulate NCL expression. Cell proliferation was detected by CCK-8 assay, and cell apoptosis and cell cycle were determined by flow cytometry. Transcriptome next-generation sequencing (NGS) was performed to predict associated signaling pathways, the expression levels of related genes were measured by RT-PCR. RESULTS: Down-regulation of NCL expression significantly inhibited the proliferation of Kasumi-1 cells (P <0.01) and markedly increased the apoptosis rate (P <0.001). Cell cycle analysis showed significant changes in the distribution of cells in the G₁ and S phases after NCL knockdown (P <0.05), while no significant difference was observed in the G₂ phase (P >0.05). Transcriptome sequencing analysis demonstrated that differentially expressed genes in Kasumi-1 cells with low expression of NCL were primarily enriched in key signaling pathways, including ribosome, spliceosome, RNA transport, cell cycle, and amino acid biosynthesis. qPCR validation showed that the expression of BAX, CASP3, CYCS, PMAIP1, TP53 , and CDKN1A was significantly upregulated after NCL downregulation (P <0.05), with CDKN1A exhibiting the most pronounced difference. CONCLUSION NCL plays a critical role in regulating the proliferation, apoptosis, and cell cycle progression of Kasumi-1 cells. The mechanism likely involves suppressing cell cycle progression through activation of the TP53-CDKN1A pathway and promoting apoptosis by upregulating apoptosis-related genes.
Humans ; Leukemia, Myeloid, Acute/pathology* ; Down-Regulation ; Cell Proliferation ; Apoptosis ; RNA-Binding Proteins/genetics* ; Nucleolin ; Cell Line, Tumor ; Phosphoproteins/metabolism* ; Cell Cycle ; Signal Transduction ; RNA, Small Interfering

Glutamine provides carbon and nitrogen to support the proliferation of cancer cells. However, the precise reason why cancer cells are particularly dependent on glutamine remains unclear. In this study, we report that glutamine modulates the tumor suppressor F-box and WD repeat domain-containing 7 (FBW7) to promote cancer cell proliferation and survival. Specifically, lysine 604 (K604) in the sixth of the 7 substrate-recruiting WD repeats of FBW7 undergoes glutaminylation (Gln-K604) by glutaminyl tRNA synthetase. Gln-K604 inhibits SCFFBW7-mediated degradation of c-Myc and Mcl-1, enhances glutamine utilization, and stimulates nucleotide and DNA biosynthesis through the activation of c-Myc. Additionally, Gln-K604 promotes resistance to apoptosis by activating Mcl-1. In contrast, SIRT1 deglutaminylates Gln-K604, thereby reversing its effects. Cancer cells lacking Gln-K604 exhibit overexpression of c-Myc and Mcl-1 and display resistance to chemotherapy-induced apoptosis. Silencing both c-MYC and MCL-1 in these cells sensitizes them to chemotherapy. These findings indicate that the glutamine-mediated signal via Gln-K604 is a key driver of cancer progression and suggest potential strategies for targeted cancer therapies based on varying Gln-K604 status.
Glutamine/metabolism* ; Myeloid Cell Leukemia Sequence 1 Protein/genetics* ; Humans ; Proto-Oncogene Proteins c-myc/genetics* ; Cell Proliferation ; Signal Transduction ; Neoplasms/pathology* ; F-Box-WD Repeat-Containing Protein 7/genetics* ; Cell Survival ; Cell Line, Tumor ; Apoptosis

The objective of the present study was to investigate the role and mechanism of bone marrow microenvironmental cells in regulating the mitochondrial mass of leukemia cells, and to uncover the mechanism of leukemia progression at the metabolic level. A mouse model of acute myeloid leukemia (AML) induced by the overexpression of the MLL-AF9 (MA9) fusion protein was established, and the bone marrow cells of AML mice were transplanted into mitochondrial fluorescence reporter mice expressing the Dendra2 protein (mito-Dendra2 mice). The proportion of Dendra2⁺ cells in bone marrow leukemia cells at different stages of AML was quantified by flow cytometry. The effects of transferred mitochondria on leukemia cells were studied by fluorescence-activated cell sorting (FACS), followed by functional experiments and bulk RNA sequencing. Finally, components within the bone marrow niche, such as mesenchymal stromal cells (MSCs) and endothelial cells (ECs), were co-cultured with leukemia cells in vitro. The proportion of leukemia cells that underwent mitochondrial transfer and the apoptosis level of leukemia cells were then detected by flow cytometry. The results showed that mitochondria from bone marrow cells were transferred to leukemia cells in the AML mouse model, and the proportion of mitochondrial transfer decreased with AML progression. The proportion of mitochondria transferred to leukemia stem cells (LSCs) was lower than that of mature AML cells. In AML cells receiving Dendra2⁺ mitochondria, there was a significant increase in the levels of intracellular reactive oxygen species (ROS) and apoptosis, while the levels of protein translation and their colony-forming capacities were decreased. The transplantation of Dendra2⁺ AML cells resulted in an extension of the survival of mice. RNA sequencing analysis demonstrated a significant downregulation of pathways related to translation, aerobic respiration and mitochondrial organization in AML cells that had received mitochondria. In vitro co-culture experiments indicated that MSCs within the bone marrow niche tended to transfer their mitochondria to leukemia cells and promoted the apoptosis of leukemia cells. These results indicate that in the MA9-induced AML mouse model, bone marrow niche cells can transfer mitochondria to leukemia cells, resulting in a reduction in the overall survival and function of the leukemia cells. Mitochondrial transfer in the bone marrow microenvironment may serve as a self-defensive mechanism of the host bone marrow niche cells, inhibiting the progression of AML.
Animals ; Mice ; Mitochondria/metabolism* ; Disease Progression ; Leukemia, Myeloid, Acute/genetics* ; Apoptosis ; Mesenchymal Stem Cells/metabolism* ; Bone Marrow Cells/metabolism* ; Humans ; Tumor Microenvironment ; Mice, Inbred C57BL

OBJECTIVE: To explore the effect of abnormal miRNA expression on the proliferation of pediatric acute lymphoblastic leukemia (ALL) cells and its related mechanism. METHODS: 15 children with ALL and 15 healthy subjects were collected from the Second Affiliated Hospital of Hainan Medical University from July 2018 to March 2021. MiRNA sequencing was performed on their bone marrow cells, and validated using qRT-PCR. MiR-1294 and miR-1294-inhibitory molecule (miR-1294-inhibitor) were transfected into Nalm-6 cells, and the proliferation of Nalm-6 cells was detected by CCK-8 and colony formation assays. Western blot and ELISA were used to detect apoptosis of Nalm-6 cells. Biological prediction of miR-1294 was performed to find the target gene, which was verified by luciferase reporter assay. Si-SOX15 was transfected into Nalm-6 cells, Western blot was used to detect the expression of Wnt signaling pathway-related proteins and to verify the effect of si-SOX15 on the proliferation and apoptosis of Nalm-6 cells. RESULTS: Compared with healthy subjects, 22 miRNAs were significantly upregulated in bone marrow cells of ALL patients, of which miR-1294 was the most significantly upregulated. In addition, the expression level of SOX15 gene was significantly reduced in bone marrow cells of ALL patients. Compared with the NC group, the miR-1294 group showed increased protein expression levels of Wnt3a and β-catenin, faster cell proliferation, and more colony-forming units, while caspase-3 protein expression level and cell apoptosis were reduced. Compared with the NC group, the miR-1294-inhibitor group showed reduced protein expression levels of Wnt3a and β-catenin, slower cell proliferation, and fewer colony-forming units, while caspase-3 protein expression level was increased and apoptosis rate was elevated. miR-1294 had a complementary base-pair with the 3'UTR region of SOX15 , and miR-1294 directly targeted SOX15 . The expression of miR-1294 was negatively correlated with SOX15 in ALL cells. Compared with the si-NC group, the si-SOX15 group showed increased protein expression levels of Wnt3a and β-catenin, accelerated cell proliferation, and decreased caspase-3 protein expression level and cell apoptosis rate. CONCLUSION MiR-1294 can target and inhibit SOX15 expression, thus activating the Wnt/β-Catenin signaling pathway to promote the proliferation of ALL cells, inhibit cell apoptosis, and ultimately affect the disease progression.
Humans ; Child ; beta Catenin/genetics* ; Wnt Signaling Pathway ; Caspase 3/metabolism* ; Cell Line, Tumor ; MicroRNAs/genetics* ; Cell Proliferation ; Precursor Cell Lymphoblastic Leukemia-Lymphoma ; Apoptosis ; SOX Transcription Factors/metabolism*

OBJECTIVE: To investigate the clinical significance of SFRP1 gene and its methylation in childhood acute lymphoblastic leukemia (ALL) . METHODS: Methylation-specific PCR (MSP) was used to detect the methylation status of SFRP1 gene in bone marrow mononuclear cells of 43 children with newly diagnosed ALL before chemotherapy (primary group) and when the bone marrow reached complete remission d 46 after induction of remission chemotherapy (remission group), the expression of SFRP1 mRNA was detected by quantitative real-time polymerase chain reaction (qRT-PCR), the expression of SFRP1 protein was detected by Western blot, and clinical data of children were collected, the clinical significance of SFRP1 gene methylation in children with ALL was analyze. RESULTS: The positive rate of SFRP1 gene promoter methylation in the primary group (44.19%) was significantly higher than that in the remission group (11.63%) (χ2=11.328, P<0.05). The relative expression levels of SFRP1 mRNA and protein in bone marrow mononuclear cells of children in the primary group were significantly lower than those in the remission group (P<0.05). Promoter methylation of SFRP1 gene was associated with risk level (χ2=15.613, P=0.000) and survival of children (χ2=6.561, P=0.010) in the primary group, children with SFRP1 hypermethylation had significantly increased risk and shortened event-free survival time, but no significant difference in other clinical data. CONCLUSION Hypermethylation of SFRP1 gene promoter may be involved in the development of childhood ALL, and its hypermethylation may be associated with poor prognosis.
Child ; Humans ; Clinical Relevance ; DNA Methylation ; Precursor Cell Lymphoblastic Leukemia-Lymphoma/genetics* ; Bone Marrow/metabolism* ; RNA, Messenger/metabolism* ; Membrane Proteins/genetics* ; Intercellular Signaling Peptides and Proteins/metabolism*

OBJECTIVE: To explore the expression level of exosome derived miR-181b-5p in different disease stages of children with acute lymphoblastic leukemia and its relationship with clinical characteristics. METHODS: Bone marrow plasma samples of 86 children with ALL were collected. Exosomes were extracted by exosome extraction kit, and RNA in exosomes was extracted by TRIzol method. The levels of miR-181b-5p in the blood plasma exosomes of the patients in the newly diagnosed group, relapse group, remission group and control group were detected by qRT- PCR. The difference of miR-181b-5p expression level in each group was compared and analyzed, and the relationship between miR-181b-5p expression level and clinical characteristics was analyzed. RESULTS: The expression level of exosomal miR-181b-5p in the newly diagnosed group and the relapsed group was significantly lower than that in the remission group and the control group (P< 0.05). The expression level of exosomal miR-181b-5p in T-ALL children was higher than that in B-ALL children (P<0.05). The expression level of plasma exosomal miR-181b-5p in male children was higher than that in female children (P<0.01). CONCLUSION Exosome derived miR-181b-5p changes dynamically in the course of ALL children, and can be used as a marker miRNA to monitor disease status. Exosomes can transmit information in the tumor microenvironment and serve as a potential carrier for biomolecular targeted therapy.
Humans ; Male ; Female ; Child ; Exosomes/metabolism* ; Clinical Relevance ; MicroRNAs/genetics* ; Precursor Cell Lymphoblastic Leukemia-Lymphoma/metabolism* ; Tumor Microenvironment

OBJECTIVE: To investigate the expression and significance of regulatory T cells (Tregs), FoxP3 and transforming growth factor-β (TGF-β) in different phase of chronic myeloid leukemia (CML). METHODS: Peripheral blood of 73 CML patients in Department of Hematology, Heze Municipal Hospital from March 2018 to March 2021 were collected. According to patient's period in CML, they were divided into ND CML group (newly diagnosed), CP CML group (chronic period), and BP CML group (blast phase). The percentage of Tregs, expression level of FoxP3 mRNA and TGF-β were detected by flow cytometry, RT-qPCR, and ELISA, respecitively. The roles of above indices in clinical pathogenesis of patients with CML were analyzed. RESULTS: The proportion of Treg in the ND CML group was slightly higher than the CP CML group, but the difference was not statistically significant (P =0.695), while the BP CML group was significantly higher than the other two groups (P =0.008, P <0.001). The expression levels of FoxP3 mRNA in ND CML group, CP CML group and BP CML group were 11.61±2.21, 6.46±1.35 and 8.54±2.13, respectively. Significant difference in FoxP3 mRNA levels was observed among patients in different phases of CML (F =55.199, P <0.001). The expression levels of FoxP3 mRNA both in ND CML group and BP CML group were significantly higher than that in CP CML group (P <0.001), and the ND CML group was the highest (P <0.001). However, the expression levels of TGF-β in different phases of CML showed no statistical differences (H =0.634, P =0.728). CONCLUSION The abnormal distribution of Treg subset in different phases of CML and the significant increase of the expression level of FoxP3 mRNA in the new onset and blast phase of CML suggest that Tregs may promote the occurrence and progression of CML through immune regulation.
Humans ; Blast Crisis/metabolism* ; Forkhead Transcription Factors/metabolism* ; Leukemia, Myelogenous, Chronic, BCR-ABL Positive/genetics* ; RNA, Messenger/metabolism* ; T-Lymphocytes, Regulatory/metabolism* ; Transforming Growth Factor beta/metabolism*

Obesity-associated protein (FTO) is an important m6A demethylase that regulates RNA methylation modification and can promote the proliferation of acute myeloid leukemia(AML) cells. FTO regulates the methylation level of AML through multiple cellular signaling pathways such as FTO/RARA/ASB2, FTO/m6A/CEBPA, and PDGFRB/ERK, and participates in the occurrence, development, treatment and prognosis of AML. At present, studies have found that a variety of inhibitors targeting FTO have shown good anti-leukemia effects, and the study of FTO will provide new ideas for the treatment of AML. This review focus on the mechanism of action of FTO in AML and the research progress of FTO inhibitors in AML.
Humans ; Methylation ; Leukemia, Myeloid, Acute/genetics* ; Prognosis ; Alpha-Ketoglutarate-Dependent Dioxygenase FTO/metabolism*