OBJECTIVES: Multiple myeloma (MM) is a highly heterogeneous hematologic malignancy, with disease progression driven by cytogenetic abnormalities and a complex bone marrow microenvironment. This study aims to construct a prognostic model for MM based on transcriptomic data and lipid metabolism related genes (LRGs), and to identify potential drug targets for high-risk patients to support clinical decision-making. METHODS: In this study, 2 transcriptomic datasets covering 985 newly diagnosed MM patients were retrieved from the Gene Expression Omnibus (GEO) database. Univariate Cox regression and 101 machine learning algorithms were used for gene selection. An LRG-based prognostic model was constructed using Stepwise Cox (both directions) and random survival forest (RSF) algorithms. The association between the prognostic score and clinical events was evaluated, and model performance was assessed using time-dependent receiver operating characteristic (ROC) curves and the C-index. The added predictive value of combining prognostic scores with clinical variables and staging systems was also analyzed. Differentially expressed genes between high- and low-risk groups were identified using limma and clusterProfiler and subjected to pathway enrichment analysis. Drug sensitivity analysis was conducted using the Genomics of Drug Sensitivity in Cancer (GDSC) database and oncoPredict to identify potential therapeutic targets for high-risk patients. The functional role of key LRGs in the model was validated via in vitro cell experiments. RESULTS: An LRG-based prognostic model (LRG17) was successfully developed using transcriptomic data and machine learning. The model demonstrated robust predictive performance, with area under the curve (AUC) values of 0.962, 0.912, and 0.842 for 3-, 5-, and 7-year survival, respectively. Patients were stratified into high- and low-risk groups, with high-risk patients showing significantly shorter overall survival (OS) and event-free survival (EFS) (both P<0.001) and worse clinical profiles (e.g., lower albumin, higher β2-microglobulin and lactate dehydrogenase levels). Enrichment analysis revealed that high-risk patients were significantly enriched for pathways related to chromosome segregation and mitosis, whereas low-risk patients were enriched for immune response and immune cell activation pathways. Drug screening suggested that AURKA inhibitor BMS-754807 and FGFR3 inhibitor I-BET-762 may be more effective in high-risk patients. Functional assays demonstrated that silencing of key LRG PLA2G4A significantly inhibited cell viability and induced apoptosis. CONCLUSIONS LRGs serve as promising biomarkers for prognosis prediction and risk stratification in MM. The overexpression of chromosomal instability-related and high-risk genetic event-associated genes in high-risk patients may explain their poorer outcomes. Given the observed resistance to bortezomib and lenalidomide in high-risk patients, combination therapies involving BMS-754807 or I-BET-762 may represent effective alternatives.
Humans ; Multiple Myeloma/mortality* ; Prognosis ; Lipid Metabolism/genetics* ; Transcriptome ; Machine Learning ; Male ; Female ; Gene Expression Profiling ; Algorithms

Multiple myeloma (MM) is a common hematologic malignancy that originates from precursor conditions such as monoclonal gammopathy of undetermined significance (MGUS) and smoldering multiple myeloma (SMM). Identifying its risk factors is crucial for early intervention. The etiology of MM is multifactorial, involving race, familial clustering, gender, age, obesity, cytogenetic abnormalities, and environmental exposures. Among these, cytogenetic abnormalities and modifiable factors play pivotal roles in MM pathogenesis and progression. 1) cytogenetic abnormalities. Primary abnormalities [e.g., hyperdiploidy, t(11;14), t(14;16)] emerge at the MGUS stage, while secondary abnormalities [e.g., 1q+, del(17p)] drive disease progression. The accumulation of 1q+ promotes clonal evolution, and del(17p) is associated with significantly reduced survival. 2) modifiable risk factors. Obesity promotes MM via the acetyl-CoA synthetase 2 (ACSS2)-interferon regulatory factor 4 (IRF4) pathway. Vitamin D deficiency weakens immune surveillance. Exposure to herbicides such as Agent Orange and glyphosate increases MGUS incidence. Insufficient UV exposure, by reducing vitamin D synthesis, elevates MM risk. Gut microbiota dysbiosis (enrichment of nitrogen-cycle bacteria and depletion of short-chain fatty acids producers) induces chromosomal instability through the ammonium ion-solute carrier family 12 member 22 (SLC12A2)-NEK2 axis. Therefore, risk-based screening among high-risk populations (e.g., those who are obese, elderly, or chemically exposed), along with early interventions targeting cytogenetic abnormalities [e.g., B cell lymphoma 2 (Bcl-2) inhibitors for t(11;14), ferroptosis inducers for t(4;14)] and modifiable factors (e.g., vitamin D supplementation, gut microbiota modulation), may effectively delay disease progression and improve prognosis.
Humans ; Multiple Myeloma/epidemiology* ; Risk Factors ; Obesity/complications* ; Chromosome Aberrations ; Monoclonal Gammopathy of Undetermined Significance/etiology* ; Gastrointestinal Microbiome ; Vitamin D Deficiency/complications* ; Precancerous Conditions/genetics*

Humans ; Multiple Myeloma/genetics* ; Karyotyping ; Translocation, Genetic/genetics*

Objective This study aims to construct and identify the chimeric antigen receptor NK92 (CAR-NK92) cells targeting NKG2D ligand (NKG2DL) (secreting IL-15Ra-IL-15) and verify the killing activity of NKG2D CAR-NK92 cells against multiple myeloma cells. Methods The extracellular segment of NKG2D was employed to connect 4-1BB and CD3Z, as well as IL-15Ra-IL-15 sequence to obtain a CAR expression framework. The lentivirus was packaged and transduced into NK92 cells to obtain NKG2D CAR-NK92 cells. The proliferation of NKG2D CAR-NK92 cells was detected by CCK-8 assay, IL-15Ra secretion was detected by ELISA and killing efficiency was detected by lactate dehydrogenase (LDH) assay. The molecular markers of NKp30, NKp44, NKp46, the ratio of apoptotic cell population, CD107a, and the secretion level of granzyme B and perforin were detected using flow cytometry. In addition, the cytotoxic mechanism of NKG2D CAR-NK92 cells on the tumor was verified by measuring the degranulation ability. Moreover, after NKG2D antibody inhibited effector cells and histamine inhibited tumor cells, LDH assay was utilized to detect the effect on cell-killing efficiency. Finally, the multiple myeloma tumor xenograft model was constructed to verify its anti-tumor activity in vivo. Results Lentiviral transduction significantly increased NKG2D expression in NK92 cells. Compared with NK92 cells, the proliferation ability of NKG2D CAR-NK92 cells was weaker. The early apoptotic cell population of NKG2D CAR-NK92 cells was less, and NKG2D CAR-NK92 cells had stronger cytotoxicity to multiple myeloma cells. Additionally, IL-15Ra secretion could be detected in its culture supernatant. NKp44 protein expression in NKG2D CAR-NK92 cells was clearly increased, demonstrating an enhanced activation level. Inhibition test revealed that the cytotoxicity of CAR-NK92 cells to MHC-I chain-related protein A (MICA) and MICB-positive tumor cells was more dependent on the interaction between NKG2D CAR and NKG2DL. After stimulating NKG2D CAR-NK92 cells with tumor cells, granzyme B and perforin expression increased, and NK cells obviously upregulated CD107α. Furthermore, multiple myeloma tumor xenograft model revealed that the tumors of mice treated with NKG2D CAR-NK92 cells were significantly reduced, and the cell therapy did not sensibly affect the weight of the mice. Conclusion A type of CAR-NK92 cell targeting NKG2DL (secreting IL-15Ra-IL-15) is successfully constructed, indicating the effective killing of multiple myeloid cells.
Humans ; Mice ; Animals ; Receptors, Chimeric Antigen/genetics* ; Interleukin-15 ; NK Cell Lectin-Like Receptor Subfamily K/metabolism* ; Granzymes ; Cell Line, Tumor ; Multiple Myeloma/therapy* ; Perforin

OBJECTIVE: To investigate the association between the expression level of platelet-activating factor acetylhydrolase 1B3 (PAFAH1B3 ) gene in bone marrow CD138⁺ cells of patients with multiple myeloma (MM) treated with autologous hematopoietic stem cell transplantation (AHSCT) and the prognosis within 2 years. METHODS: 147 MM patients treated with AHSCT in The First and The Second Affiliated Hospital of Nantong University from May 2014 to May 2019 were included in the study. Expression level of PAFAH1B3 mRNA in bone marrow CD138⁺ cells of the patients was detected. Patients with disease progression or death during 2 years of follow-up were included in progression group, and the rest were included in good prognosis group. After comparing the clinical data and PAFAH1B3 mRNA expression levels of the two groups, the patients were divided into high PAFAH1B3 expression group and low PAFAH1B3 expression group based on the median PAFAH1B3 mRNA expression level of the enrolled patients. Progression-free survival rate (PFSR) between the two groups was compared by the Kaplan-Meier method. The related factors of prognosis within 2 years were analyzed by univariate analysis and multivariate COX regression analysis. RESULTS: At the end of follow-up, there were 13 patients lost to follow-up. Finally, 44 patients were included in the progression group and 90 patients were included in the good prognosis group. Age in the progression group was higher than that in the good prognosis group, the proportion of patients with CR+VGPR after transplantation in the progression group was lower than that in the good prognosis group, and there was a statistical difference between two groups in the cases distribution of ISS stage (all P<0.05). PAFAH1B3 mRNA expression level and the proportion of patients with LDH>250U/L in the progression group were higher than those in the good prognosis group, and platelet count in the progression group was lower than that in the good prognosis group (all P<0.05). Compared with the low PAFAH1B3 expression group, the 2-year PFSR of the high PAFAH1B3 expression group was significantly lower (log-rank χ²=8.167, P=0.004). LDH>250U/L (HR=3.389, P=0.010), PAFAH1B3 mRNA expression (HR=50.561, P=0.001) and ISS stage Ⅲ(HR=1.000, P=0.003) were independent risk factors for prognosis in MM patients, and ISS stage Ⅰ (HR=0.133, P=0.001) was independent protective factor. CONCLUSION The expression level of PAFAH1B3 mRNA in bone marrow CD138⁺ cells is related to the prognosis of MM patients treated with AHSCT, and detecting PAFAH1B3 mRNA expression can bring some information for predicting PFSR and prognostic stratification of patients.
Humans ; Disease Progression ; Hematopoietic Stem Cell Transplantation ; Multiple Myeloma/drug therapy* ; Prognosis ; Retrospective Studies ; Transplantation, Autologous ; 1-Alkyl-2-acetylglycerophosphocholine Esterase/genetics*

Extramedullary plasma cell tumor (EMP) is a kind of plasma cell tumor, and its pathogenesis is not completely clear. According to whether it is independent of myeloma disease, it can be divided into primary and secondary EMP, which have different biological and clinical characteristics. Primary EMP has low invasion, fewer cytogenetic and molecular genetic abnormalities and good prognosis, and surgery and / or radiotherapy are the mainly treatments. Secondary EMP, as the extramedullary invasive progression of multiple myeloma (MM), is often accompanied by high-risk cellular and molecular genetic abnormalities and poor prognosis, chemotherapy, immunotherapy and hematopoietic stem cell transplantation are the mainly treatment. This paper reviews the latest research progress of EMP in the pathogenesis, cytogenetics molecular genetics and treatment, so as to provide reference for clinical work.
Humans ; Plasmacytoma/surgery* ; Prognosis ; Multiple Myeloma/genetics* ; Hematopoietic Stem Cell Transplantation

OBJECTIVE: To analyze the expression level of nicotinamide phosphoribosyltransferase (NAMPT ) in bone marrow of multiple myeloma (MM) patients and its correlation with clinicopathological features, clinical efficacy and prognosis. METHODS: RT-qPCR and Western blot were used to detect the expression of NAMPT mRNA and protein in bone marrow mononuclear cells from 85 newly diagnosed MM patients (including 17 relapsed MM patients) and 15 healthy donors, and explore the correlation of the expression of NAMPT gene with clinicopathological features and efficacy. Kaplan-Meier method was used to analyze the effects of NAMPT on progression-free survival (PFS) and overall survival (OS), and univariate and multivariate survival analysis were performed. RESULTS: The median expression level of NAMPT mRNA in bone marrow of newly diagnosed and relapsed MM patients was significantly higher than that of healthy donors (P <0.001). The expression of NAMPT mRNA in relapsed MM patients was significantly higher than that in newly diagnosed MM patients (P <0.001), which was consistent with the expression of NAMPT protein. ISS staging, lactate dehydrogenase and C-reactive protein levels, p53 deletion and the proportion of myeloma cells were increased in high NAMPT expression group compared with low NAMPT expression group (P <0.001). Compared with complete remission group, NAMPT mRNA expression was significantly up-regulated in partial remission group, progression group and relapsed group (P <0.001). The median OS and PFS of patients in high NAMPT expression group was 27.3 and 14.9 months, respectively, which was significantly shorter than 39.1 and 27 months in low NAMPT expression group (P =0.048, P <0.001). Both univariate and multivariate analysis showed that NAMPT expression was correlated with PFS and OS. CONCLUSION The expression level of NAMPT in newly diagnosed and relapsed MM patients is significantly higher than that in normal controls, and its up-regulation is related to the adverse clinical characteristics, efficacy and prognosis of MM patients. NAMPT is an independent prognostic risk factor of MM.
Humans ; Multiple Myeloma/genetics* ; Nicotinamide Phosphoribosyltransferase ; Prognosis ; RNA, Messenger/genetics* ; Treatment Outcome

OBJECTIVE: To investigate the biological function of miR-203a-5p and the underlying mechanism in multiple myeloma (MM). METHODS: Three miRNA expression profiles (GSE16558, GSE24371 and GSE17498) were downloaded from the GEO database. The three miRNA expression profiles contained 131 MM samples and 17 normal plasmacyte samples. The robust rank aggregation (RRA) method was used to identify the differentially expressed miRNAs between MM and normal plasmacytes. In order to carry out cytological experiments, MM cell line with stable over-expression of miR-203a-5p was constructed with lentivirus. Expression levels of miR-203a-5p in MM cells were quantified by qRT-PCR. The effects of miR-203a-5p on MM cells were investigated using assays of cell viability and cell cycle. Cell proliferation was measured using the Cell Counting kit (CCK)8 assay. The percentage of cells in each cell cycle was measured with a FACSCalibur system. Xenograft tumor models were established to evaluate the role of miR-203a-5p in tumorigenesis in vivo . To elucidate the underlying molecular mechanisms of miR-203a-5p in mediating cell proliferation inhibition and cell cycle arrest in MM, we used TargetScan and miRanda to predict the candidate targets of miR-203a-5p. The potential target of miR-203a-5p in MM cells was explored using the luciferase reporter assay, qRT-PCR, and Western blot. RESULTS: An integrated analysis of three MM miRNA expression datasets showed that the levels of miR-203a-5p in MM were notably downregulated compared with those in normal plasmacytes. Accordingly, the relative expression levels of miR-203a-5p were decreased in MM cell lines. In addition, overexpression of miR-203a-5p inhibited the proliferation and cell cycle progression of RPMI8226 and U266 cells. In vivo experiments demonstrated that upregulation of miR-203a-5p expression could significantly inhibit the tumorigenesis of subcutaneous myeloma xenografts in nude mice. Mechanistic investigation led to the identification of Jagged 1 (JAG1) as a novel and direct downstream target of miR-203a-5p. Interestingly, the reintroduction of JAG1 abrogated miR-203a-5p-induced MM cell growth inhibition and cell cycle arrest. CONCLUSION Our data demonstrate that miR-203a-5p inhibits cell proliferation and cell cycle progression in MM cells by targeting JAG1, supporting the utility of miR-203a-5p as a novel and potential therapeutic agent for miRNA-based MM therapy.
Animals ; Mice ; Humans ; Multiple Myeloma/pathology* ; Cell Line, Tumor ; Mice, Nude ; MicroRNAs/metabolism* ; Cell Division ; Cell Proliferation ; Disease Models, Animal ; Carcinogenesis/genetics* ; Gene Expression Regulation, Neoplastic ; Jagged-1 Protein/metabolism*

OBJECTIVES: Multiple myeloma (MM) is a plasma cell malignancy occurring in middle and old age. MM is still an incurable disease due to its frequent recurrence and drug resistance. However, its pathogenesis is still unclear. Abnormal amino acid metabolism is one of the important characteristics of MM, and the important metabolic pathway of amino acids participates in protein synthesis as basic raw materials. Aminoacyl transfer ribonucleic acid synthetase (ARS) gene is a key regulatory gene in protein synthesis. This study aims to explore the molecular mechanism for ARS, a key factor of amino acid metabolism, in regulating amino acid metabolism in MM and affecting MM growth. METHODS: The corresponding gene number was combined with the gene expression profile GSE5900 dataset and GSE2658 dataset in Gene Expression Omnibus (GEO) database to standardize the gene expression data of ARS. GSEA_4.2.0 software was used to analyze the difference of gene enrichment between healthy donors (HD) and MM patients in GEO database. GraphPad Prism 7 was used to draw heat maps and perform data analysis. Kaplan-Meier and Cox regression model were used to analyze the expression of ARS gene and the prognosis of MM patients, respectively. Bone marrow samples from 7 newly diagnosed MM patients were collected, CD138⁺ and CD138^- cells were obtained by using CD138 antibody magnetic beads, and the expression of ARS in MM clinical samples was analyzed by real-time RT-PCR. Human B lymphocyte GM12878 cells and human MM cell lines ARP1, NCI-H929, OCI-MY5, U266, RPMI 8266, OPM-2, JJN-3, KMS11, MM1.s cells were selected as the study objects. The expression of ARS in MM cell lines was analyzed by real-time RT-PCR and Western blotting. Short hairpin RNA (shRNA) lentiviruses were used to construct gene knock-out plasmids (VARS-sh group). No-load plasmids (scramble group) and gene knock-out plasmids (VARS-sh group) were transfected into HEK 293T cells with for virus packaging, respectively. Stable expression cell lines were established by infecting ARP1 and OCI-MY5 cells, and the effects of knockout valyl-tRNA synthetase (VARS) gene on proliferation and apoptosis of MM cells were detected by cell counting and flow cytometry, respectively. GEO data were divided into a high expression group and a low expression group according to the expression of VARS. Bioinformatics analysis was performed to explore the downstream pathways affected by VARS. Gas chromatography time-of-flight mass spectrometry (GC-TOF/MS) and high performance liquid chromatography (HPLC) were used to detect the valine content in CD138⁺ cells and ARP1, OCI-MY5 cells and supernatant of knockdown VARS gene in bone marrow samples from patients, respectively. RESULTS: Gene enrichment analysis showed that tRNA processing related genes were significantly enriched in MM compared with HD (P<0.0001). Further screening of tRNA processing-pathway related subsets revealed that cytoplasmic aminoacyl tRNA synthetase family genes were significantly enriched in MM (P<0.0001). The results of gene expression heat map showed that the ARS family genes except alanyl-tRNA synthetase (AARS), arginyl-tRNA synthetase (RARS), seryl-tRNA synthetase (SARS) in GEO data were highly expressed in MM (all P<0.01). With the development of monoclonal gammopathy of undetermined significance (MGUS) to MM, the gene expression level was increased gradually. Kaplan-Meier univariate analysis of survival results showed that there were significant differences in the prognosis of MM patients in methionyl-tRNA synthetase (MARS), asparaginyl-tRNA synthetase (NARS) and VARS between the high expression group and the low expression group (all P<0.05). Cox regression model multivariate analysis showed that the high expression of VARS was associated with abnormal overall survival time of MM (HR=1.83, 95% CI 1.10 to 3.06, P=0.021). The high expression of NARS (HR=0.90, 95% CI 0.34 to 2.38) and MARS (HR=1.59, 95% CI 0.73 to 3.50) had no effect on the overall survival time of MM patients (both P>0.05). Real-time RT-PCR and Western blotting showed that VARS, MARS and NARS were highly expressed in CD138⁺ MM cells and MM cell lines of clinical patients (all P<0.05). Cell counting and flow cytometry results showed that the proliferation of MM cells by knockout VARS was significantly inhibited (P<0.01), the proportion of apoptosis was significantly increased (P<0.05). Bioinformatics analysis showed that in addition to several pathways including the cell cycle regulated by VARS, the valine, leucine and isoleucine catabolic pathways were upregulated. Non-targeted metabolomics data showed reduced valine content in CD138⁺ tumor cells in MM patients compared to HD (P<0.05). HPLC results showed that compared with the scramble group, the intracellular and medium supernatant content of ARP1 cells and the medium supernatant of OCI-MY5 in the VARS-shRNA group was increased (all P<0.05). CONCLUSIONS MM patients with abnormal high expression of VARS have a poor prognosis. VARS promotes the malignant growth of MM cells by affecting the regulation of valine metabolism.
Humans ; Valine-tRNA Ligase ; Multiple Myeloma/genetics* ; Metabolomics ; Amino Acids ; RNA, Transfer

OBJECTIVE: To investigate the effect of adipocytes in the bone marrow microenvironment of patients with multiple myeloma (MM) on the pathogenesis of MM. METHODS: Bone marrow adipocytes (BMA) in bone marrow smears of health donors (HD) and newly diagnosed MM (ND-MM) patients were evaluated with oil red O staining. The mesenchymal stem cells (MSC) from HD and ND-MM patients were isolated, and in vitro co-culture assay was used to explore the effects of MM cells on the adipogenic differentiation of MSC and the role of BMA in the survival and drug resistance of MM cells. The expression of adipogenic/osteogenic differentiation-related genes PPAR-γ, DLK1, DGAT1, FABP4, FASN and ALP both in MSC and MSC-derived adipocytes was determined with real-time quantitative PCR. The Western blot was employed to detect the expression levels of IL-6, IL-10, SDF-1α, TNF-α and IGF-1 in the supernatant with or without PPAR-γ inhibitor. RESULTS: The results of oil red O staining of bone marrow smears showed that BMA increased significantly in patients of ND-MM compared with the normal control group, and the BMA content was related to the disease status. The content of BMA decreased in the patients with effective chemotherapy. MM cells up-regulated the expression of MSC adipogenic differentiation-related genes PPAR-γ, DLK1, DGAT1, FABP4 and FASN, but the expression of osteogenic differentiation-related gene ALP was significantly down-regulated. This means that the direct consequence of the interaction between MM cells and MSC in the bone marrow microenvironment is to promote the differentiation of MSC into adipocytes at the expense of osteoblasts, and the cytokines detected in supernatant changed. PPAR-γ inhibitor G3335 could partially reverse the release of cytokines by BMA. Those results confirmed that BMA regulated the release of cytokines via PPAR-γ signal, and PPAR-γ inhibitor G3335 could distort PPAR-γ mediated BMA maturation and cytokines release. The increased BMA and related cytokines effectively promoted the proliferation, migration and drug resistance of MM cells. CONCLUSION The BMA and its associated cytokines are the promoting factors in the survival, proliferation and migration of MM cells. BMA can protect MM cells from drug-induced apoptosis and plays an important role in MM treatment failure and disease progression.
Humans ; Osteogenesis/genetics* ; Bone Marrow/metabolism* ; Multiple Myeloma/metabolism* ; Drug Resistance, Neoplasm ; Peroxisome Proliferator-Activated Receptors/pharmacology* ; Cell Differentiation ; Adipogenesis ; Cytokines/metabolism* ; Adipocytes/metabolism* ; Bone Marrow Cells/metabolism* ; Cells, Cultured ; PPAR gamma/pharmacology* ; Tumor Microenvironment