Exosome-shuttled FTO from BM-MSCs contributes to cancer malignancy and chemoresistance in acute myeloid leukemia by inducing m6A-demethylation: A nano-based investigation.

Although bone marrow mesenchymal stem cells (BM-MSCs)-derived exosomes have been reported to be closely associated with acute myeloid leukemia (AML) progression and chemo-resistance, but its detailed functions and molecular mechanisms have not been fully delineated. Besides, serum RNA m6A demethylase fat mass and obesity-associated protein (FTO)-containing exosomes are deemed as important indicators for cancer progression, and this study aimed to investigate the role of BM-MSCs-derived FTO-exosomes in regulating the malignant phenotypes of AML cells. Here, we verified that BM-MSCs-derived exosomes delivered FTO to promote cancer aggressiveness, stem cell properties and Cytosine arabinoside (Ara-C)-chemoresistance in AML cells, and the underlying mechanisms were also uncovered. Our data suggested that BM-MSCs-derived FTO-exo demethylated m6A modifications in the m6A-modified LncRNA GLCC1 to facilitate its combination with the RNA-binding protein Hu antigen R (HuR), which further increased the stability and expression levels of LncRNA GLCC1. In addition, LncRNA GLCC1 was verified as an oncogene to facilitate cell proliferation and enhanced Ara-C-chemoresistance in AML cells. Further experiments confirmed that demethylated LncRNA GLCC1 served as scaffold to facilitate the formation of the IGF2 mRNA binding protein 1 (IGF2BP1)-c-Myc complex, which led to the activation of the downstream tumor-promoting c-Myc-associated signal pathways. Moreover, our rescuing experiments validated that the promoting effects of BM-MSCs-derived FTO-exo on cancer aggressiveness and drug resistance in AML cells were abrogated by silencing LncRNA GLCC1 and c-Myc. Thus, the present firstly investigated the functions and underlying mechanisms by which BM-MSCs-derived FTO-exo enhanced cancer aggressiveness and chemo-resistance in AML by modulating the LncRNA GLCC1-IGF2BP1-c-Myc signal pathway, and our work provided novel biomarkers for the diagnosis, treatment and therapy of AML in clinic.

Bone mesenchymal stem cell-derived exosomal microRNA-7-5p inhibits progression of acute myeloid leukemia by targeting OSBPL11.

BACKGROUND: Acute myeloid leukemia (AML) is a malignant clonal disease of hematopoietic stem- and progenitor-cell origin. AML features massive proliferation of abnormal blasts and leukemia cells in the bone marrow and the inhibition of normal hematopoiesis at onset. Exosomes containing proteins or nucleic acids are secreted by cells; they participate in intercellular communication and serve as key modulators of hematopoiesis. The purpose of this study was to investigate the effects of exosomes derived from bone marrow mesenchymal stem cells (BMSCs) on the regulation of AML and the underlying mechanisms mediated by microRNA (miRNA). METHODS: Dysregulated miR-7-5p in AML patients was identified using qRT-PCR and its clinical significance was explored. Bioinformatic analysis revealed the target gene OSBPL11 that could be regulated by miR-7-5p. The findings were validated using a dual-luciferase reporter assay and western blotting. The functional genes of the PI3K/AKT/mTOR signaling pathway were identified, and the functional significance of miR-7-5p in AML cells was determined using a functional recovery assay. AML cells were co-cultured with exosomes originating from BMSCs overexpressing miR-7-5p to determine cell-cell regulation by Exo-miR-7-5p, as well as in vitro and in vivo functional validation via gain- and loss-of-function methods. RESULTS: Expression of miR-7-5p was decreased in AML patients and cells. Overexpression of miR-7-5p curbed cellular proliferation and promoted apoptosis. Overexpression of OSBPL11 reversed the tumorigenic properties of miR-7-5p in AML cells in vitro. Exo-miR-7-5p derived from BMSCs induced formation of AML cells prone to apoptosis and a low survival rate, with OSBPL11 expression inhibited through the PI3K/AKT/mTOR signaling pathway. Exo-miR-7-5p derived from BMSCs exhibited tumor homing effects in vitro and in vivo, and inhibited AML development. CONCLUSIONS: Exo-miR-7-5p derived from BMSCs negatively regulates OSBPL11 by suppressing the phosphorylation of the PI3K/AKT/mTOR signaling pathway, thereby inhibiting AML proliferation and promoting apoptosis. The data will inform the development of AML therapies based on BMSC-derived exosomes.

Pyruvate dehydrogenase kinase 4-mediated metabolic reprogramming is involved in rituximab resistance in diffuse large B-cell lymphoma by affecting the expression of MS4A1/CD20.

Diffuse large B cell lymphoma (DLBCL) heterogeneity promotes recurrence and anti-CD20-based therapeutic resistance. Previous studies have shown that downregulation of MS4A1/CD20 expression after chemoimmunotherapy with rituximab leads to rituximab resistance. However, the mechanisms of CD20 loss remain unknown. We identified that pyruvate dehydrogenase kinase 4 (PDK4) is markedly elevated in DLBCL cells derived from both patients and cell lines with R-CHOP (rituximab plus cyclophosphamide, doxorubicin, vincristine, and prednisone) resistance. We found that overexpression of PDK4 in DLBCL cells resulted in cell proliferation and resistance to rituximab in vitro and in vivo. Furthermore, loss of PDK4 expression or treatment with the PDK4 inhibitor dichloroacetate was able to significantly increase rituximab-induced cell apoptosis in DLBCL cells. Further studies suggested PDK4 mediates a metabolic shift, in that the main energy source was changed from oxidative phosphorylation to glycolysis, and the metabolic changes could play an important role in rituximab resistance. Importantly, by knocking down or overexpressing PDK4 in DLBCL cells, we showed that PDK4 has a negative regulation effect on MS4A1/CD20 expression. Collectively, this is the first study showing that targeting PDK4 has the potential to overcome rituximab resistance in DLBCL.

PRICKLE1, a Wnt/PCP signaling component, is overexpressed and associated with inferior prognosis in acute myeloid leukemia.

BACKGROUND: Prickle planar cell polarity protein 1 (PRICKLE1), a core component of the non-canonical Wnt/planar cell polarity (PCP) pathway, was recently reported to be upregulated and correlated with poor prognosis in solid cancers. However, the effect of PRICKLE1 on acute myeloid leukemia (AML) remains unknown. This study aims to characterize the prognostic significance of PRICKLE1 expression in patients with AML. METHODS: RNA-seq was performed to compare mRNA expression profiles of AML patients and healthy controls. qRT-PCR and western blotting were used to analyze the expression of PRICKLE1 in AML patients and cell lines, and two independent datasets (TCGA-LAML and TARGET-AML) online were used to validate the expression results. The correlations between the expression of PRICKLE1 and clinical features were further analyzed. RESULTS: Our data showed that PRICKLE1 expression levels were markedly high in AML patients at the time of diagnosis, decreased after complete remission and increased again at relapse. Of note, PRICKLE1 was highly expressed in drug resistant AML cells and monocytic-AML patients. High PRICKLE1 expression was found in FLT3/DNMT3A/IDH1/IDH2-mutant AML and associated with poor prognosis. Furthermore, high expression of PRICKLE1 may be correlated with migration and invasion components upregulation in AML patients. CONCLUSIONS: These results indicated that high PRICKLE1 expression may be a poor prognostic biomarker and therapeutic target of AML.

Biomimetic nanotherapy: core-shell structured nanocomplexes based on the neutrophil membrane for targeted therapy of lymphoma.

BACKGROUND: Non-Hodgkin's lymphoma (NHL) is a malignant disease of lymphoid tissue. At present, chemotherapy is still the main method for the treatment of NHL. R-CHOP can significantly improve the survival rate of patients. Unfortunately, DOX is the main cytotoxic drug in R-CHOP and it can lead to adverse reactions. Therefore, it is particularly important to uncover new treatment options for NHL. RESULTS: In this study, a novel anti-tumor nanoparticle complex Nm@MSNs-DOX/SM was designed and constructed in this study. Mesoporous silica nanoparticles (MSNs) loaded with Doxorubicin (DOX) and anti-inflammatory drugs Shanzhiside methylester (SM) were used as the core of nanoparticles. Neutrophil membrane (Nm) can be coated with multiple nanonuclei as a shell. DOX combined with SM can enhance the anti-tumor effect, and induce apoptosis of lymphoma cells and inhibit the expression of inflammatory factors related to tumorigenesis depending on the regulation of Bcl-2 family-mediated mitochondrial pathways, such as TNF-α and IL-1ß. Consequently, the tumor microenvironment (TME) was reshaped, and the anti-tumor effect of DOX was amplified. Besides, Nm has good biocompatibility and can enhance the EPR effect of Nm@MSNs-DOX/SM and increase the effect of active targeting tumors. CONCLUSIONS: This suggests that the Nm-modified drug delivery system Nm@MSNs-DOX/SM is a promising targeted chemotherapy and anti-inflammatory therapy nanocomplex, and may be employed as a specific and efficient anti-Lymphoma therapy.

Clinical study on ixazomib in the treatment of multiple myeloma. / ä¼Šæ²™ä½ç±³æ²»ç–—å¤šå‘æ€§éª¨é«“ç˜¤çš„ä¸´åºŠç ”ç©¶.

OBJECTIVES: To evaluate the efficacy and safety of ixazomib in the treatment of multiple myeloma. METHODS: A total of 43 patients with multiple myeloma were given ixazomib-based chemotherapy, including 16 patients with relapsed/refractory multiple myeloma (RRMM group), 27 patients newly diagnosed multiple myeloma with serious adverse events initially treated with bortezomib (conversion treatment group). Single ixazomib or ixazomib-based 2- or 3-medicine regimens combined with dexamethasone and lenalidomide or thalidomide or cyclophosphamide were performed, and then the response and safety were assessed. RESULTS: The overall response rate (ORR) was 56.25%, and the rate of very good partial response (VGPR) was 18.75% in the RRMM group. Most effective patients were those with long-term recurrence. The ORR was 88.89% in the conversion treatment group, which was further improved compared with the ORR of 81.48% before the conversion, among which 59.26% had a further remission. The main adverse events included thrombocytopenia, leucopenia, diarrhea, asthenia, rash, joint pain, etc. CONCLUSIONS: Lxazomib is effective in treating the patients with later recurrence and the patients with serious adverse events initially treated with bortezomib. Lxazomib may not be effective in patients with recent relapse after bortezomib treatment. The adverse events are controllable.

[Effect of all-trans retinoid acid and G-CSF on growth, differentiation and RARα2 expression of myeloma cells].

OBJECTIVE: To investigate the effect of all-trans retinoid acid (ATRA) and granulocyte colony-stimulating factor (G-CSF) on the growth, apoptosis, differentiation and expression of RARα2 of myeloma cells. METHODS: Myeloma cell lines OPM2 (RARα2 positive) and U266 (RARα2 negative) were treated with ATRA in the presence or absence of G-CSF. The cells were divided into 6 groups: control groups, G-CSF groups (treated with 1000 U/ml and 2000 U/ml), ATRA groups (treated with 1.0 µmol/L ATRA) and combined groups (treated with 1000 U/mL or 2000 U/mL G-CSF plus 1.0 µmol/L ATRA). The cell viability, growth and apoptosis were examined by MTT method, inverted microscopy and Annexin-V/PI staining, respectively; RARα2 expression was detected by reverse transcription PCR; morphology change was evaluated by Wright-Giemsa staining; CD49e expression were analyzed by flow cytometry. RESULTS: The proliferation of OPM2 cells was inhibited by ATRA treatment (P<0.05) . The growth inhibition rates in combined groups were higher than corresponding single ATRA groups (P<0.05). However, the above effects in U266 cells were not significant (P >0.05). The OPM2 cell stained by Wright-Giemsa in ATRA groups showed that the cell nucleus became smaller, chromatin condensed, number of nucleolus reduced, the volume of cytoplasm increased and the cytoplasm became dark blue. Expression rates of CD49e were low in both U266 and OPM2 cells. Expression of RARα2 in OPM2 cells of combination groups were higher than those of control group and corresponding single groups (P<0.05); and there was no significant difference between control group and G-CSF groups (P>0.05). Expression of RARα2 in U266 cells of control group and G-CSF groups was not detected; and ATRA groups and combination groups had weak expression. CONCLUSION: ATRA can induce proliferation inhibition in RARα2-expressing myeloma cells, and it may also play a certain role in promoting differentiation of RARα2 positive myeloma cells.

Predictive factors for peripheral blood stem cell mobilization in multiple myeloma in the era of novel therapies: A single-center experience.

OBJECTIVE: Multiple myeloma (MM) is the leading indication of autologous hematopoietic stem cell transplantation. The aim of this study was to determine the incidence of mobilization failure and characterize the risk factors associated with poor mobilization (PM) of MM patients in novel therapies era. METHODS: We conducted a retrospective study of 211 MM patients who received their first peripheral blood stem cells (PBSC) mobilization at our single center. The following data were collected: age, gender, clinical stage, disease status, complete blood cell count, induction regimen, CD34+ cell count in peripheral blood (PB), and PBSC collections. RESULTS: In addition to conventional drugs, 22 (10.4%) patients received daratumumab containing induction, and 33 (15.6%) patients used plerixafor for poor mobilization (pre-apheresis PB CD34+ cells <20/µL). Failure of collection occurred in 24 (11.4%) patients and was correlated with low white blood cell (WBC), ≥3 cycles of lenalidomide treatment before mobilization, steady-state mobilization and nouse of plerixafor are associated with mobilization failure. Daratumumab-based induction treatment ≥2 courses, albumin >41 g/L before mobilization, and steady-state mobilization were risk factors for PM in subgroups of patients treated with lenalidomide for <3 courses. In addition, Hepatitis B virus infection at baseline, thalassemia and measurable residual disease positivity were recognized as predictive factors for PM in subset of chemo-mobilization patients. CONCLUSION: In addition to some well-recognized risk factors, baseline WBC count and daratumumab exposure ≥2 courses before mobilization were revealed as the predictive factors of mobilization failure, providing consultation for preemptive use of plerixafor.

The clinical significance of TAT, PIC, TM, and t-PAIC in vascular events of BCR/ABL-negative myeloproliferative neoplasms.

Predicting the likelihood vascular events in patients with BCR/ABL1-negative myeloproliferative neoplasms (MPN) is essential for the treatment of the disease. However, effective assessment methods are lacking. Thrombin-antithrombin complex (TAT), plasmin-α2- plasmininhibitor complex (PIC), thrombomodulin (TM), and tissue plasminogen activator-inhibitor complex (t-PAIC) are the new direct indicators for coagulation and fibrinolysis. The aim of this study was to investigate the changes of these four new indicators in thrombotic and hemorrhagic events in BCR/ABL1-negative MPN. The study cohort of 74 patients with BCR/ABL negative myeloproliferative disorders included essential thrombocythemia, polycythemia vera, and primary myelofibrosis (PMF). A panel of 4 biomarkers, including TAT, PIC, TM, and t-PAIC were determined using Sysmex HISCL5000 automated analyzers, whereas fibrin/fibrinogen degradation products (FDP), D-dimer and Antithrombin III (ATIII) were analyzed using Sysmex CS5100 coagulation analyzer. A total of 24 (32.4%) patients experienced thrombotic events and hemorrhagic events occurred in 8 patients (10.8%). Compared to patients without hemorrhagic-thrombotic events, patients with thrombotic events had higher fibrinogen (FIB) level, FDP level and lower ATIII activity, while patients with hemorrhagic events had lower white blood cell count and hemoglobin level, higher FDP level (P < 0.05). Patients with a JAK2V617F mutation were more likely to experience thrombotic events (P < 0.05). In addtion, patients with thrombotic events had higher TAT, PIC, TM, and t-PAIC levels than patients without hemorrhagic-thrombotic events (P < 0.05), whereas patients with hemorrhagic events had a lower median value in TAT and TM (no statistical difference, P > 0.05). Patients with higher TAT, TM and t-PAIC were more likely to experience thrombotic events (P < 0.05), and only TAT was positively correlated with thrombotic events (Spearman r =0.287, P = 0.019). TAT, PIC, TM, and t-PAIC combined with ATIII and FDP have a certain value for predicting thrombosis in patients with BCR/ABL1-negative MPN. These 6 parameters are worth further exploration as predictive factors and prognostic markers for early thrombotic events.

Targeting gut microbial nitrogen recycling and cellular uptake of ammonium to improve bortezomib resistance in multiple myeloma.

The gut microbiome has been found to play a crucial role in the treatment of multiple myeloma (MM), which is still considered incurable due to drug resistance. In previous studies, we demonstrated that intestinal nitrogen-recycling bacteria are enriched in patients with MM. However, their role in MM relapse remains unclear. This study highlights the specific enrichment of Citrobacter freundii (C. freundii) in patients with relapsed MM. Through fecal microbial transplantation experiments, we demonstrate that C. freundii plays a critical role in inducing drug resistance in MM by increasing levels of circulating ammonium. The ammonium enters MM cells through the transmembrane channel protein SLC12A2, promoting chromosomal instability and drug resistance by stabilizing the NEK2 protein. We show that furosemide sodium, a loop diuretic, downregulates SLC12A2, thereby inhibiting ammonium uptake by MM cells and improving progression-free survival and curative effect scores. These findings provide new therapeutic targets and strategies for the intervention of MM progression and drug resistance.

m6A genotypes and prognostic signature for assessing the prognosis of patients with acute myeloid leukemia.

BACKGROUND: N6-methyladenosine (m6A) has been confirmed to function critically in acute myeloid leukemia (AML) progression. Hitherto, the subtyping and prognostic predictive significance of m6A-correlated genes in AML is unclear. METHOD: From The Cancer Genome Atlas (TCGA-LAML), Therapeutically Applicable Research to Generate Effective Treatments (TARGET-AML) and Gene Expression Omnibus (GEO, GSE71014) databases, we collected the sequencing data of AML patients. The batch effect was removed via limma package for TCGA-LAML and TARGET-AML, and the aggregated samples were AML cohorts. Samples in the AML cohort identified m6A models in AML by consensus clustering based on 23-m6A-related modulators. M6A-related differentially expressed genes (m6ARDEGs) influencing the overall survival (OS) of AML were determined by performing differential expression analysis and univariate COX analysis, and consensus-based clustering was utilized to access AML molecular subtypes. LASSO and multivariate COX analyses were performed to obtain the optimized m6ARDEGs to construct the m6A Prognostic Risk Score (m6APR_Score). Whether the model was robust was evaluated according to Kaplan-Meier (K-M) and receiver operator characteristic (ROC) curves. Further, the abundance of immune cell infiltration was explored in different m6A modification patterns and molecular subtypes and m6APR_Score groupings. Finally, nomogram was constructed to predict OS in AML. Quantitative real-time polymerase chain reaction (RT-qPCR) and cell counting kit-8 (CCK-8) assay were used to validate the genes in m6APR_Score in AML cells. RESULTS: The m6A models (m6AM1, m6AM2, m6AM3) and molecular subtypes (C1, C2, C3) were identified in the AML cohort, exhibiting different prognosis and immunoreactivity. We recognized novel prognostic biomarkers of AML such as CD83, NRIP1, ACSL1, METTL7B, OGT, and C4orf48. AML patients were grouped into high-m6APR_Score and low-m6APR_Score groups, with the later group showing a better prognosis than former one. Both the AML cohort and the validation cohort GSE71014 demonstrated excellent prediction. Finally, the nomogram accurately predicted the survival of patients suffering from AML. Further, the decision curves showed that both nomogram and m6APR_Score showed excellent prediction. It was confirmed in vitro experiments that mRNA expressions of NRIP1, ACSL1, METTL7B and OGT were elevated, while CD83 and C4orf48 mRNA expressions downregulated in AML cells. A significant increase in the viability of U937 and THP-1 cell lines after inhibition of CD83, while siMETTL7B had contrast results. CONCLUSION: Our study demonstrated that m6APR_Score and CD83, NRIP1, ACSL1, METTL7B, OGT, and C4orf48 potentially provided novel and promising prognostic support for AML patients.

Clinical implications and genetical insights of SOX6 expression in acute myeloid leukemia.

BACKGROUND: Transcription factor SOX6 belongs to Sry-related high-mobility-group box (SOX) family, has been reported to be downregulated and acts as a tumor-suppressor gene in various solid tumors, but in acute myeloid leukemia (AML) is incompletely understood. METHODS: The SOX6 expression was analyzed between AML patients and normal controls from public data and our research cohort. Correlations between SOX6 expression and clinical, genetic features together with survival were further analyzed. RESULTS: In both public and our present datasets, we demonstrated that SOX6 expression is notably downregulated in AML patients compared with normal controls. Moreover, the expression level of SOX6 was dynamic, along with the disease status. SOX6 was significantly decreased in relapsed/refractory AML compared with complete remission AML. Clinically, SOX6 underexpression was significantly correlated with bone marrow blasts, and WBC counts. Furthermore, decreased expression of SOX6 was more common in core binding factor AML (CBF-AML), rarely found in complex karyotype AML (CK-AML), and correlated with FLT3 mutations. By survival analyses, low-expression of SOX6 was associated with shorter overall survival (OS) and event-free survival (EFS) among cytogenetic normal AML (CN-AML) patients. Moreover, both univariate and multivariate analyses showed that low SOX6 expression was an independent unfavorable prognostic biomarker for CN-AML. CONCLUSIONS: Our findings indicated that SOX6 underexpression, as a frequent event in AML, was associated with genetic abnormalities and prognosis in AML. SOX6 might be a valuable biomarker for risk stratification, predicting prognosis and relapse of AML.

MMP9-Associated Tumor Stem Cells, CCL1-Silenced Dendritic Cells, and Cytokine-Induced Killer Cells Have a Remarkable Therapeutic Efficacy for Acute Myeloid Leukemia by Activating T Cells.

Purpose: Dendritic cells (DC) are specialized antigen-presenting cells, and cytokine-induced killer (CIK) cells have a specific killing activity to a variety of tumors. However, the underlining mechanism and function of DC-CIK cells in acute myeloid leukemia (AML) remain largely elusive. Methods: Gene expression profiles of leukemia patients were obtained from TCGA, DC cell components were evaluated using the quanTIseq method, and cancer stem cell scores were estimated using machine learning methods. The transcriptomes were obtained in DC-CIK cells from normal and AML patients by high-throughput sequencing. Large differentially expressed mRNAs were verified by RT-qPCR assay, and MMP9 and CCL1 were selected for subsequent studies in vivo and in vitro experiments. Results: Significant positive correlations were found with DC versus cancer stem cells (p = 0.008) and the expression of MMP9 versus cancer stem cells (p = 0.018). MMP9 and CCL1 were found to be highly expressed in DC-CIK cells from AML patients. DC-CIK cells with MMP9 and CCL1 knockout alone had little effect on leukemia cells, while knockdown of MMP9 and CCL1 in DC-CIK cells increased cytotoxicity, suppressed proliferation, and induced apoptosis of leukemia cells. In addition, we proved that MMP9- and CCL1-silenced DC-CIK cells significantly elevated the CD3+CD4+ and CD3+CD8+ cells and lowered the CD4+PD-1+ and CD8+PD-1+ T cells. Meanwhile, blockage of MMP9 and CCL1 in DC-CIK cells dramatically increased IL-2 and IFN-γ, increased CD107aþ (LAMP-1) and granzyme B (GZMB), and downregulated PD-1, CTLA4, TIM3, and LAG3 T cells from AML patients and AML model mice. Furthermore, activated T cells in DC-CIK cells knocking down MMP9 and CCL1 also prevented proliferation and accelerated apoptosis of AML cells. Conclusion: Our findings demonstrated that blockage of MMP9 and CCL1 in DC-CIK cells could markedly enhance the therapeutic efficiency in AML via activating T cells.

Flow Cytometric Analysis of Bone Marrow Particle Cells for Measuring Minimal Residual Disease in Multiple Myeloma.

Minimal residual disease (MRD) is one of the most relevant prognostic factors in patients with multiple myeloma (MM). However, the hemodilution of bone marrow (BM) aspirates, the most common preanalytical problem, is known to affect MRD detection. In the present study, we analyzed a preanalytical method for routine BM aspirates and a bone marrow particle cell (BMPL) enrichment assay and validated it as a reliable preanalytical method for flow cytometric MRD determination. A total of 120 BM samples were taken from 103 MM patients consecutively recruited; 77 BM samples had BMPL enrichment analysis and 99 BM samples were routinely analyzed. Then, the two different samples from patients with MM were sent for MRD detection using an eight-color flow cytometry. Our data showed that assessment of the BMPL enrichment samples attenuated the overestimation of MRD-negative assessed in the routine BM samples, which was mainly caused by hemodilution. In conclusion, the BMPL enrichment assay is a functional and practical preanalytical method for flow cytometric MRD analysis.

Efficacy Evaluation of Inflammatory Mediators in the Treatment of Multiple Myeloma with Daratumumab.

Objective: This study aimed to investigate the regulatory ability and clinical therapeutic effect of daratumumab on inflammatory mediators in patients with multiple myeloma. Method: The Multiple Myeloma Public Genetic Data Array download GSE125361 dataset was collected. The GO analysis and KEGG analysis were performed on the differential genes to elucidate the multiple myeloma cytokine-related gene pathways. Daratumumab is a CD38 monoclonal antibody used to treat multiple myeloma. Patients with newly diagnosed multiple myeloma were treated with monoclonal antibodies containing CD38, and the control group was treated with a regimen without daratumumab. The serum levels of IL-2, IL-4, IL-6, IL-10, TNF-α, and IFN-γ were measured in the two groups before and after treatment and the therapeutic effects of the two groups were compared. Result: The KEGG analysis showed that the Th17 cell differentiation, apoptosis, and cytokine-cytokine receptor interaction pathways were differentially expressed in multiple myeloma. The expression levels of serum IL-2, IL-6, IL-10, and TNF-α in patients in the daratumumab group were lower than those in the control group after chemotherapy. The overall effective rate of patients treated with daratumumab after chemotherapy was higher than that of the control group. Conclusion: Daratumumab can effectively improve the levels of IL-2, IL-6, IL-10, and TNF-α in patients with multiple myeloma and improve the therapeutic effect.

Hypoxia-Immune-Related Gene SLC19A1 Serves as a Potential Biomarker for Prognosis in Multiple Myeloma.

Background: Multiple myeloma (MM) remains an incurable malignant tumor of plasma cells. Increasing evidence has reported that hypoxia and immune status contribute to the progression of MM. In this research, the prognostic value of the hypoxia-immune-related gene SLC19A1 in MM was evaluated by bioinformatics analysis. Method: RNA-sequencing (RNA-seq) data along with clinical information on MM were downloaded from the Gene Expression Omnibus (GEO) database. Consistent clustering analysis and ESTIMATE algorithms were performed to establish the MM sample subgroups related to hypoxia and immune status, respectively, based on the GSE24080 dataset. The differentially expressed analysis was performed to identify the hypoxia-immune-related genes. Subsequently, a hypoxia-immune-gene risk signature for MM patients was constructed by univariate and multivariate Cox regression analyses, which was also verified in the GSE4581 dataset. Furthermore, the mRNA expression of SLC19A1 was determined using qRT-PCR in 19 MM patients, and the correlations between the genetic expression of SLC19A1 and clinical features were further analyzed. Result: A total of 47 genes were identified as hypoxia-immune-related genes for MM. Among these genes, SLC19A1 was screened to construct a risk score model that had better predictive power for MM. The constructed prognostic signature based on SLC19A1 was verified in the GSE4581 dataset. All independent prognostic factors (age, ß2-microglobulin, LDH, albumin, MRI, and gene risk score) were used to develop a nomogram that showed a better performance for predicting the survival probability of MM patients for 1-5 years. Furthermore, SLC19A1 was highly expressed in newly diagnosed and relapsed MM patients, and high expression of SLC19A1 is correlated with higher bone marrow aspiration plasma cells and ß2-microglobulin levels in MM patients. Conclusion: In conclusion, our results suggest that SLC19A1 is aberrantly expressed in MM and highly expressed SLC19A1 might be a biomarker correlated with inferior prognosis. More importantly, we identified SLC19A1 as a hypoxia-immune-related gene in MM. Future functional and mechanistic studies will further clarify the roles of SLC19A1 in MM.

Chidamide-Induced Accumulation of Reactive Oxygen Species Increases Lenalidomide Sensitivity Against Multiple Myeloma Cells.

BACKGROUND: Lenalidomide, an immunomodulatory drug (IMiD), is an effective therapy for the treatment of multiple myeloma (MM). However, prolonged treatment may be accompanied by toxicity, second primary malignancies, and drug resistance. There is an inherent vulnerability in MM cells that high rates of immunoglobulin synthesis resulting in the high level of reactive oxygen species (ROS). This provides a therapeutic potential for MM. MATERIALS AND METHODS: The intracellular ROS levels, H2O2 production and glutathione (GSH) levels were measured using detection kit. Cell viability was evaluated using cell-counting kit-8 (CCK-8) and soft agar colony formation assay. Apoptosis was determined in whole living cells using flow cytometry. Chidamide and its anti-myeloma efficacy in combination with lenalidomide were characterized in MM cell lines in vitro and in a mouse xenograft model. Moreover, Western blotting, immunofluorescence and immunohistochemical studies were performed. RESULTS: ROS levels increased in a time- and dose-dependent manner with chidamide treatment. Moreover, the GSH levels were decreased and the mRNA level of SLC7A11 downregulated after chidamide treatment. The co-treatment with chidamide and lenalidomide increased apoptosis and proliferation inhibition, with combination index (CI) in the synergistic range (0.2-0.5) using the Chou-Talalay method. The cooperative anti-myeloma efficacy was confirmed in the murine model, and immunohistochemical studies also supported this potentiation. Chidamide enhanced the effect of lenalidomide-induced degradation of IKZF1 and IKZF3 by elevating H2O2. In addition, co-treatment with chidamide and lenalidomide increased biomarkers of caspase and DNA damage. CONCLUSION: Elevated ROS production may constitute a potential biochemical basis for anti-myeloma effects of chidamide plus lenalidomide. The results of this study confirm the synergistic effect of chidamide and lenalidomide against MM and provide a promising therapeutic strategy for MM.

Chidamide, a subtype-selective histone deacetylase inhibitor, enhances Bortezomib effects in multiple myeloma therapy.

Drug resistance is the major cause for disease relapse and patient death in multiple myeloma (MM). It is an urgent need to develop new therapies to overcome drug resistance in MM. Chidamide (CHI), a novel oral HDAC inhibitor targeting HDAC1, 2, 3 and 10, has shown potential therapeutic effect in MM. In this study, we determined that CHI exhibited significant anti-tumor effect on MM cells both in vitro and in vivo, which was positively correlated with the expression of HDAC1. Meanwhile, CHI enhanced Bortezomib (BTZ) effects synergistically in MM cells and a combination of CHI with BTZ induced myeloma cell apoptosis and G0/G1 arrest in vitro and in vivo. Mechanistically, the synergistic anti-tumor effect of CHI and BTZ was related with the increased production of reactive oxygen species (ROS) dependent DNA damage and the changes of cell apoptosis and cycle pathways. Our data indicate that CHI may be a suitable drug to sensitize BTZ in MM cells, which provides novel insight into the therapy for MM patients.

LncRNA NEAT1 sponges miR-214 to regulate M2 macrophage polarization by regulation of B7-H3 in multiple myeloma.

BACKGROUND: LncRNA NEAT1 was associated with the tumorigenesis of multiple myeloma (MM). However, the mechanisms of M2 macrophage polarization involved with NEAT1 in MM are still unknown. METHODS: Bone marrow samples, multiple myeloma cells RPMI 8226 and monocyte cell line THP-1 were used in this study. The expression of NEAT1 and miR-214 was modified by transfection with the shNEAT1 or miR-214 inhibitor. The expression of NEAT1, miR-214 and B7-H3 in MM patient tissues and cells was analyzed by RT-qPCR. ELISA assay was used to determine the release of B7-H3 in the supernatant of cell culture. The patient survival curve was analyzed using Kaplan-Meier method. The macrophage polarization markers were examined by RT-qPCR and western blotting. The interaction between NEAT1, miR-214 and B7-H3 was analyzed by Dual-Luciferase reporter and RIP assays. AG490 was used to block the JAK2/STAT3 signaling. Co-culture of THP-1 and RPMI 8226 cells was used for macrophage polarization. RESULTS: NEAT1 and B7-H3 were up-regulated, but miR-214 was obviously down-regulated in MM patients. B7-H3, NEAT1 and miR-214 were associated with overall survival time of MM patients. NEAT1 silencing induced miR-214 and inhibited the expression and release of B7-H3 and then suppressed M2 macrophage polarization via inhibiting the JAK2/STAT3 signaling. NEAT1 directly targeted miR-214, and miR-214 directly bound to B7-H3. MiR-214 inhibitor reversed the down-regulation and release of B7-H3 and M2 macrophage polarization caused by shNEAT1. The specific JAK2/STAT3 signaling inhibitor AG490 abrogated M2 macrophage polarization. CONCLUSION: NEAT1 promoted M2 macrophage polarization by sponging miR-214 and then regulating B7-H3, thus accelerating MM progression via the JAK2/STAT3 signaling pathway. Our study revealed novel mechanisms of M2 macrophage polarization and provided new potential clinical therapeutic targets for MM.