OBJECTIVE: To study the expression of SPOP in patients with acute myeloid leukemia (AML) and its effect on proliferation, apoptosis and cycle of AML cells. METHODS: RT-qPCR was used to detect the expression of SPOP mRNA in bone marrow samples of patients with newly diagnosed AML and normal controls. The stable overexpression of SPOP in AML cell lines THP-1 and U937 were constructed by liposome transfection. The effect of SPOP on cell proliferation was detected by CCK-8, and the effect of SPOP on apoptosis and cell cycle was detected by flow cytometry. The expressions of anti-apoptotic protein Bcl-2 and apoptotic protein Bax, Caspase3 were detected by Western blot. RESULTS: The median expression level of SPOP mRNA in normal control group was 0.993 1(0.6303, 1.433), while that in AML group was 0.522 1(0.242 2, 0.723 7). The expression level of SPOP in AML group was significantly lower than that in normal control group ( P < 0.001). After the overexpression of SPOP, the proportion of apoptotic cells in the U937 overexpression group and THP-1 overexpression group was 10.9%±0.3% and 4.6%±015%, which were higher than 8.9%±0.3% and 3.0%±0.30% in the Empty Vector group, respectively (both P < 0.05). The expression of Caspase3 in U937 overexpression group and THP-1 overexpression group was 1.154±0.086 and 1.2±0.077, which were higher than 1 in Empty Vector group, respectively (both P < 0.05). The ratio of Bax/Bcl-2 in U937 overexpression group and THP-1 overexpression group was 1.328±0.057 and 1.669±0.15, which were higher than 1 in Empty Vector group, respectively (both P < 0.05). In the cell proliferation experiment, the number of cells in the U937 overexpression group and THP-1 overexpression group were both slightly lower than those in the Empty Vector group, but the differences were not statistically significant (P >0.05). In the cell cycle experiment, the proportion of G₁ cells in the U937 overexpression group and THP-1 overexpression group were both slightly higher than those in the Empty Vector group, but the differences were not statistically significant (P >0.05). CONCLUSION SPOP can promote the apoptosis of leukemic cells, and its mechanism may be related to down-regulation of Bcl-2 expression and up-regulation of Bax and Caspase3 expression.
Humans ; Leukemia, Myeloid, Acute/pathology* ; Apoptosis ; Repressor Proteins/genetics* ; Cell Proliferation ; Nuclear Proteins/genetics* ; Cell Cycle ; Proto-Oncogene Proteins c-bcl-2/metabolism* ; Caspase 3/metabolism* ; bcl-2-Associated X Protein/metabolism* ; U937 Cells ; Cell Line, Tumor ; RNA, Messenger/genetics*

OBJECTIVE: To study the effects and mechanisms of juglone on the proliferation and apoptosis of acute myeloid leukemia (AML) cells. METHODS: Juglone and AML targets were collected from public databases, and the intersecting target clusters were taken for functional enrichment analysis to explore the potential mechanism of juglone in the treatment of AML. Then wet experiments were performed to verify. AML cell lines including KG-1a, MV-411, THP-1 and MOLM-13 were treated with different concentrations of juglone for 24 h. MTT assay was used to detect cell viability and determine the IC₅₀, and the most sensitive cell line was screened for subsequent experiments. Flow cytometry was used to detect the apoptosis of cells treated with different concentrations of juglone. Western blot was performed to check the expression of relevant proteins. RESULTS: Eleven targets were obtained as potential targets for juglone in the treatment of AML, and the top ten significantly enriched pathways were intrinsic pathway of apoptosis, programmed cell death, cytochrome c-mediated apoptotic response, apoptosis, apoptotic factor-mediated response, regulated necrosis, cytokine signaling in immune system, signaling by interleukins, oncogene induced senescence, and signal transduction. The cell viability of KG-1a, MV-411, THP-1 and MOLM-13 was decreased with increasing juglone concentration after 24 h of juglone treatment (r =-0.992, -0.886, -0.956, -0.910). Among them, MOLM-13 was the most sensitive to juglone. The results of flow cytometry showed that the apoptosis rate of MOLM-13 tended to significantly increase with the increasing concentration of juglone (r =0.99). At the same time point, p-RIPK1/RIPK1, p-RIPK3/RIPK3, and p-MLKL/MLK were decreased in each juglone concentration group compared with control group. CONCLUSION Juglone inhibits the viability of KG-1a, MV-411, THP-1 and MOLM-13 cells, and induces apoptosis of MOLM-13 cells, the mechanism of which may be related to the inhibition of RIPK1/RIPK3/MLKL signaling pathway.
Humans ; Naphthoquinones/pharmacology* ; Apoptosis/drug effects* ; Cell Proliferation/drug effects* ; Leukemia, Myeloid, Acute/pathology* ; Cell Line, Tumor ; Receptor-Interacting Protein Serine-Threonine Kinases/metabolism* ; Protein Kinases/metabolism* ; Signal Transduction ; Cell Survival/drug effects*

OBJECTIVE: To establish venetoclax-resistant acute myeloid leukemia (AML) cell lines, assess the sensitivity of venetoclax-resistant cell lines to the BCL-2 protein family, and investigate their resistance mechanisms. METHODS: CCK-8 method was used to screen AML cell lines (MV4-11, MOLM13, OCI-AML2) that were relatively sensitive to venetoclax. Low concentrations of venetoclax continuously induced drug-resistance development in the cell lines. Changes in cell viability and apoptosis rate before and after resistance development were measured using the CCK-8 method and flow cytometry. BH3 profiling assay was performed to anayze the transform of mitochondrion-dependent apoptosis pathway as well as the sensitivity of resistant cell lines to BCL-2 family proteins and small molecule inhibitors. Real-time fluorescence quantitative PCR (RT-qPCR) was utilized to examine changes in the expression levels of BCL-2 protein family members in both venetoclax-resistant cell lines and multidrug-resistant patients. RESULTS: Venetoclax-resistant cell lines of MV4-11, MOLM13, and OCI-AML2 were successfully established, with IC₅₀ values exceeding 10-fold. Under the same concentration of venetoclax, the apoptosis rate of resistant cells decreased significantly (P < 0.05). BH3 profiling assay revealed that the drug-resistant cell lines showed increased sensitivity to many pro-apoptotic proteins (such as BIM,BID and NOXA). RT-qPCR showed significantly upregulated MCL1 and downregulated NOXA1 were detected in drug-resistant cell lines. Expression changes in MCL1 and NOXA1 in venetoclax-resistant patients were consistent with our established drug-resistant cell line results. CONCLUSION The venetoclax-resistant AML cell lines were successfully established through continuous induction with low concentrations of venetoclax. The venetoclax resistance resulted in alterations in the mitochondrial apoptosis pathway of the cells and an increased sensitivity of cells to pro-apoptotic proteins BIM, BID, and NOXA, which may be associated with the upregulation of MCL1 expression and downregulation of NOXA1 expression in the drug-resistant cells.
Humans ; Sulfonamides/pharmacology* ; Drug Resistance, Neoplasm ; Bridged Bicyclo Compounds, Heterocyclic/pharmacology* ; Leukemia, Myeloid, Acute/pathology* ; Proto-Oncogene Proteins c-bcl-2/metabolism* ; Cell Line, Tumor ; Apoptosis ; Antineoplastic Agents/pharmacology*

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

Perineural invasion (PNI) by tumor cells is a key phenotype of highly-invasive oral squamous cell carcinoma (OSCC). Since Schwann cells (SCs) and fibroblasts maintain the physiological homeostasis of the peripheral nervous system, and we have focused on cancer-associated fibroblasts (CAFs) for decades, it's imperative to elucidate the impact of CAFs on SCs in PNI⁺ OSCCs. We describe a disease progression-driven shift of PNI^- towards PNI⁺ during the progression of early-stage OSCC (31%, n = 125) to late-stage OSCC (53%, n = 97), characterized by abundant CAFs and nerve demyelination. CAFs inhibited SC proliferation/migration and reduced neurotrophic factors and myelin in vitro, and this involved up-regulated ER stress and decreased MAPK signals. Moreover, CAFs also aggravated the paralysis of the hind limb and PNI in vivo. Unexpectedly, leukemia inhibitory factor (LIF) was exclusively expressed on CAFs and up-regulated in metastatic OSCC. The LIF inhibitor EC330 restored CAF-induced SC inactivation. Thus, OSCC-derived CAFs inactivate SCs to aggravate nerve injury and PNI development.
Schwann Cells/metabolism* ; Mouth Neoplasms/metabolism* ; Humans ; Cancer-Associated Fibroblasts/metabolism* ; Animals ; Carcinoma, Squamous Cell/metabolism* ; Neoplasm Invasiveness/pathology* ; Male ; Female ; Mice ; Cell Movement/physiology* ; Cell Proliferation/physiology* ; Cell Line, Tumor ; Leukemia Inhibitory Factor/metabolism* ; Middle Aged

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

It is reported that iron metabolism and ferroptosis can influence the occurrence and development of myeloid tumors, which can serve as therapeutic targets. Dysregulation of iron metabolism is present in a variety of myeloid neoplasms. The prognosis of acute myeloid leukemia is related to differential expression of molecules related to iron metabolism. The prognosis of myelodysplastic syndrome patients with iron overload is poor. Myeloproliferative neoplasms are often characterized by the coexistence of iron deficiency and erythrocytosis, which can be treated by targeting hepcidin. Myeloid tumor cells are susceptible to oxidative damage caused by the accumulation of reactive oxygen species and are sensitive to ferroptosis. Ferroptosis has anti-tumor effect in acute myeloid leukemia and myelodysplastic syndrome. Targeting ferroptosis can reverse imatinib resistance in chronic myeloid leukemia. This article reviews the characteristics of iron metabolism in the development and progression of myeloid neoplasms, as well as the mechanism of ferroptosis, to provide a basis for the development of new therapeutic strategies.
Ferroptosis ; Humans ; Iron/metabolism* ; Myelodysplastic Syndromes/pathology* ; Reactive Oxygen Species/metabolism* ; Leukemia, Myeloid, Acute/pathology* ; Hepcidins/metabolism* ; Iron Overload/metabolism* ; Myeloproliferative Disorders/metabolism* ; Prognosis

BACKGROUND: Imatinib mesylate (IM) resistance is an emerging problem for chronic myeloid leukemia (CML). Previous studies found that connexin 43 (Cx43) deficiency in the hematopoietic microenvironment (HM) protects minimal residual disease (MRD), but the mechanism remains unknown. METHODS: Immunohistochemistry assays were employed to compare the expression of Cx43 and hypoxia-inducible factor 1α (HIF-1α) in bone marrow (BM) biopsies of CML patients and healthy donors. A coculture system of K562 cells and several Cx43-modified bone marrow stromal cells (BMSCs) was established under IM treatment. Proliferation, cell cycle, apoptosis, and other indicators of K562 cells in different groups were detected to investigate the function and possible mechanism of Cx43. We assessed the Ca 2+ -related pathway by Western blotting. Tumor-bearing models were also established to validate the causal role of Cx43 in reversing IM resistance. RESULTS: Low levels of Cx43 in BMs were observed in CML patients, and Cx43 expression was negatively correlated with HIF-1α. We also observed that K562 cells cocultured with BMSCs transfected with adenovirus-short hairpin RNA of Cx43 (BMSCs-shCx43) had a lower apoptosis rate and that their cell cycle was blocked in G0/G1 phase, while the result was the opposite in the Cx43-overexpression setting. Cx43 mediates gap junction intercellular communication (GJIC) through direct contact, and Ca 2+ is the key factor mediating the downstream apoptotic pathway. In animal experiments, mice bearing K562, and BMSCs-Cx43 had the smallest tumor volume and spleen, which was consistent with the in vitro experiments. CONCLUSIONS Cx43 deficiency exists in CML patients, promoting the generation of MRD and inducing drug resistance. Enhancing Cx43 expression and GJIC function in the HM may be a novel strategy to reverse drug resistance and promote IM efficacy.
Animals ; Humans ; Mice ; Apoptosis ; Bone Marrow Cells ; Cell Communication ; Connexin 43/genetics* ; Gap Junctions/metabolism* ; Imatinib Mesylate/therapeutic use* ; K562 Cells ; Leukemia, Myelogenous, Chronic, BCR-ABL Positive/pathology* ; Mesenchymal Stem Cells/metabolism* ; Tumor Microenvironment ; Calcium/metabolism*

Objective: To investigate the expression of glycoprotein non metastatic melanoma protein B (GPNMB) in renal eosinophilic tumors and to compare the value of GPNMB with CK20, CK7 and CD117 in the differential diagnosis of renal eosinophilic tumors. Methods: Traditional renal tumor eosinophil subtypes, including 22 cases of renal clear cell carcinoma eosinophil subtype (e-ccRCC), 19 cases of renal papillary cell carcinoma eosinophil subtype (e-papRCC), 17 cases of renal chromophobe cell carcinoma eosinophil subtype (e-chRCC), 12 cases of renal oncocytoma (RO) and emerging renal tumor types with eosinophil characteristics [3 cases of eosinophilic solid cystic renal cell carcinoma (ESC RCC), 3 cases of renal low-grade eosinophil tumor (LOT), 4 cases of fumarate hydratase-deficient renal cell carcinoma (FH-dRCC) and 5 cases of renal epithelioid angiomyolipoma (E-AML)], were collected at the Affiliated Drum Tower Hospital of Nanjing University Medical School from January 2017 to March 2022. The expression of GPNMB, CK20, CK7 and CD117 was detected by immunohistochemistry and statistically analyzed. Results: GPNMB was expressed in all emerging renal tumor types with eosinophil characteristics (ESC RCC, LOT, FH-dRCC) and E-AML, while the expression rates in traditional renal eosinophil subtypes e-papRCC, e-chRCC, e-ccRCC and RO were very low or zero (1/19, 1/17, 0/22 and 0/12, respectively); the expression rate of CK7 in LOT (3/3), e-chRCC (15/17), e-ccRCC (4/22), e-papRCC (2/19), ESC RCC (0/3), RO (4/12), E-AML(1/5), and FH-dRCC (2/4) variedly; the expression of CK20 was different in ESC RCC (3/3), LOT(3/3), e-chRCC(1/17), RO(9/12), e-papRCC(4/19), FH-dRCC(1/4), e-ccRCC(0/22) and E-AML(0/5), and so did that of CD117 in e-ccRCC(2/22), e-papRCC(1/19), e-chRCC(16/17), RO(10/12), ESC RCC(0/3), LOT(1/3), E-AML(2/5) and FH-dRCC(1/4). GPNMB had 100% sensitivity and 97.1% specificity in distinguishing E-AML and emerging renal tumor types (such as ESC RCC, LOT, FH-dRCC) from traditional renal tumor types (such as e-ccRCC, e-papRCC, e-chRCC, RO),respectively. Compared with CK7, CK20 and CD117 antibodies, GPNMB was more effective in the differential diagnosis (P<0.05). Conclusion: As a new renal tumor marker, GPNMB can effectively distinguish E-AML and emerging renal tumor types with eosinophil characteristics such as ESC RCC, LOT, FH-dRCC from traditional renal tumor eosinophil subtypes such as e-ccRCC, e-papRCC, e-chRCC and RO, which is helpful for the differential diagnosis of renal eosinophilic tumors.
Humans ; Kidney Neoplasms/pathology* ; Carcinoma, Renal Cell/pathology* ; Diagnosis, Differential ; Angiomyolipoma/diagnosis* ; Biomarkers, Tumor/metabolism* ; Leukemia, Myeloid, Acute/diagnosis* ; Membrane Glycoproteins

Objective To investigate the effects of miR-181b-5p on cells proliferation and apoptosis in acute myeloid leukemia (AML) by targeting paired box 9 (PAX9). Methods The relationship between expression level of PAX9 and prognosis in AML patients was analyzed by gene expression profiling interactive analysis (GEPIA) database and The Cancer Genome Atlas (TCGA) database. Kasumi-1 and AML5 cells were transfected with empty vector (Vector group) or PAX9 (PAX9 group). The proliferation activity was detected by CCK-8 assay, and cells cycle and apoptosis were detected by flow cytometry. Expressions of cyclin-dependent kinase 2 (CDK2), cyclin B1 (CCNB1), B-cell lymphoma 2 (Bcl2) and Bcl2-associated X protein (BAX) were detected by Western blot analysis. The targeted microRNA (miRNA) by PAX9 was predicted by bioinformatics analysis, and the targeted effect was verified by luciferase reporter assay. The level of PAX9 mRNA was detected by real-time quantitative PCR, and expression of PAX9 protein was detected by Western blot analysis. Kasumi-1 and AML5 cells were transfected with miR-NC (miR-NC group) or miR-181b-5p (miR-181b-5p group). The cells were further transfected with PAX9 (miR-181b-5p combined with PAX9 group) in miR-181b-5p group. The proliferation, cycle and apoptosis of cells were detected by the above methods.Results GEPIA and TCGA databases showed that the expression of PAX9 was down-regulated in AML patients, which was correlated with poor prognosis. In Kasumi-1 and AML5 cells, compared with Vector group, proliferation activity of cells, percentage of cells in S phase, and expressions of CDK2, CCNB1 and Bcl2 proteins were decreased, while percentage of cells in G0/G1 phase, apoptosis rate and the expression of BAX protein were increased in PAX9 group. It was confirmed by double luciferase reporter assay that PAX9 was the target gene of miR-181b-5p. Compared with miR-NC group, proliferation activity of cells, percentage of cells in S phase, and expressions of CDK2, CCNB1 and Bcl2 proteins were increased, while percentage of cells in G0/G1 phase, apoptosis rate and the expression of BAX protein were decreased in miR-181b-5p group. Compared with miR-181b-5p group, proliferation activity of cells, percentage of cells in S phase, and expressions of CDK2, CCNB1 and Bcl2 proteins were decreased, while percentage of cells in G0/G1 phase, apoptosis rate and the expression of BAX protein were increased in miR-181b-5p combined with PAX9 group. Conclusion The miR-181b-5p can promote the proliferation of AML cells and delay apoptosis by inhibiting PAX9.
Humans ; Apoptosis/genetics* ; bcl-2-Associated X Protein ; Cell Line, Tumor ; Cell Proliferation/genetics* ; Leukemia, Myeloid, Acute/pathology* ; Luciferases ; MicroRNAs/metabolism* ; PAX9 Transcription Factor/genetics*