OBJECTIVE: To explore the significance of the plasma cell percentage and immature plasma cells in the prognosis of patients with multiple myeloma (MM). METHODS: The clinical data of 126 newly diagnosed MM patients in Gansu Provincial Hospital from June 2017 to November 2022 were retrospectively analyzed. The enrolled patients were divided into a higher plasma cell percentage group (group A) and a lower plasma cell percentage group (group B) according to the median plasma cell percentage (33.5%). The clinicopathological data of the two groups were compared, and the effect of plasma cell percentage on the prognosis of MM patients was analyzed using survival curves. On this basis, group A and group B were divided into subgroups with immature plasma cells (A1 group, B1 group) and subgroups without immature plasma cells (A2 group, B2 group), respectively, then the survival curves were used to analyze the effect of immature plasma cells on the prognosis of MM patients. RESULTS: Among the 126 patients with MM, the proportions of patients with ISS stage III, elevated β₂-microglobulin(β₂-MG) level, and immature plasma cells in Group A were significantly higher compared those in Group B ( P =0.015, P =0.028, P =0.010). The median overall survival(OS) and progression-free survival(PFS) of group A were 32 months and 10 months, respectively. The median OS of group B was not reached, and the median PFS was 32 months. The 3-year OS rates of patients in group A and group B were 46.7% and 62.2%, respectively ( P =0.021), and the 3-year PFS were 29.2% and 42.5%, respectively ( P =0.033). There were no significant differences in OS and PFS between group A1 and group A2, or between group B1 and group B2 ( P >0.05). Multivariate COX survival analysis showed that the plasma cell percentage ≥33.5%（HR=1.253, 95%CI : 0.580-2.889, P =0.018）, age ≥65 years (HR=2.206, 95%CI : 1.170-3.510, P =0.012), lactate dehydrogenase(LDH) ≥250 U/L (HR=1.180, 95%CI : 0.621-2.398, P =0.048) and β₂-MG ≥3.5 mg/L (HR=1.507, 95%CI : 0.823-3.657, P =0.036) were independent risk factors affecting OS in MM patients. CONCLUSION MM patients with a higher plasma cell percentage (≥33.5%) at the initial diagnosis have a later disease stage, poorer OS and PFS, compared to the patients with a lower percentage(<33.5%) of plasma cells. The presence or absence of immature plasma cells has no significant impact on the survival of MM patients.
Humans ; Multiple Myeloma/pathology* ; Prognosis ; Plasma Cells/cytology* ; Retrospective Studies ; Male ; Female ; Middle Aged ; Aged ; Bone Marrow

OBJECTIVE: Photodynamic therapy has become an important method in clinical tumor treatment. This study aimed to investigate the effects of hematoporphyrin on multiple myeloma (MM) and its potential applications. METHODS: The MM cell line RPMI 8226 was treated with hematoporphyrin derivative (HPD), and CCK-8 assay was used to determine cell viability, apoptosis was detected by flow cytometry, intracellular reactive oxygen species (ROS) levels were measured using a detection kit combined with flow cytometry, and Western blot assay was used to detect apoptosis-related proteins and key signaling pathway protein levels. RESULTS: The optimal incubation time for the maximum absorption of HPD in RPMI 8226 cells was 4 hours. HPD significantly inhibited the proliferation of RPMI 8226 cells in a dose- and illumination time-dependent manner ( r =0.981; r =0.961). Additionally, HPD induced apoptosis in RPMI 8226 cells, but had no significant inhibitory effect on peripheral blood mononuclear cells derived from healthy individuals. HPD combined with illumination treatment significantly increased the intracellular ROS level, upregulated the expression of apoptosis-related proteins such as cleaved PARP, cleaved caspase-3 and Bax, and down-regulated the expression of proteins that maintain cell survival, such as NF-κB and Akt. CONCLUSION The HPD can inhibit the proliferation and induce apoptosis of multiple myeloma cells.
Humans ; Multiple Myeloma/pathology* ; Hematoporphyrins/pharmacology* ; Apoptosis/drug effects* ; Cell Line, Tumor ; Reactive Oxygen Species/metabolism* ; Cell Proliferation/drug effects* ; Photochemotherapy ; Cell Survival/drug effects* ; Signal Transduction

Bone marrow microenvironment is a highly complex environment surrounding tumor, which plays an important role in the survival, proliferation, drug resistance and migration of multiple myeloma (MM) cells. As an important cellular component in tumor microenvironment, tumor-associated macrophages(TAM) has attracted attention due to its key role in tumor progression and drug resistance. Targeting TAM has shown potential therapeutic value in cancer treatment. In order to clarify the role of macrophages in MM progression, it is necessary to understand the differentiation of TAM and its characteristics of promoting MM. This paper reviews the research progress on how TAM is programmed in MM and the mechanism of TAM promoting tumor development and drug resistance.
Humans ; Multiple Myeloma/pathology* ; Tumor-Associated Macrophages ; Macrophages/pathology* ; Cell Differentiation ; Tumor Microenvironment

The multiple myeloma (MM), the second most common hematologic malignancy, is malignant proliferative disease of plasma cells. Although the application of many targeted drugs has significantly prolonged the survival time of MM patients, it is still an incurable disease. In recent years, the immunosuppression caused by interaction between tumor microenvironment(TME) and tumor cells has attracted people's attention gradually. As a kind of immunosuppressive cells in TME, regulatory T cells (Treg) play an important role in the progress of MM. Treg is related to the proliferation and metastasis of tumors, and can lead to the progress of MM by promoting the angiogenesis and generating immunosuppressive TME. In this review, we briefly summarized the latest research progress on the impact of Treg on the pathogenesis of MM.
Humans ; Multiple Myeloma/pathology* ; T-Lymphocytes, Regulatory/pathology* ; Immune Tolerance ; Plasma Cells/pathology* ; Immunosuppression Therapy ; Tumor Microenvironment

OBJECTIVE: To explore the biological function of LINC00174 in multiple myeloma (MM). METHODS: Real-time quantitative polymerase chain reaction (RT-qPCR) was used to detect the expressions of LINC00174 and miR-150 in peripheral blood of MM patients and MM cell lines. EdU staining and flow cytometry were used to detect the effects of LINC00174 and miR-150 on the proliferation and apoptosis of MM cells. Western blot was used to detect the expressions of proliferation marker nuclear-related antigen Ki67, apoptosis-related protein cleaved caspase-3 and transcription factor forkhead box protein P1 (FOXP1). Bioinformatics and dual-luciferase reporter assay were used to verify the targeting relationship between LINC00174 and miR-150 and the targeting relationship between miR-150 and FOXP1. RESULTS: The level of LINC00174 was significantly increased in peripheral blood of MM patients and MM cell lines (P <0.05). Compared with NC-siRNA group, the expression of LINC00174 was significantly reduced in LINC00174-siRNA group, the proliferation of U266 cells was reduced, the apoptosis rate was significantly increased, the level of Ki67 protein was reduced, and the level of cleaved caspase-3 protein was increased (all P <0.05). LINC00174 targeted regulation of the expression of miR-150. Compared with LINC00174-siRNA+NC inhibitor group, the expression of miR-150 in U266 cells in LINC00174-siRNA+miR-150 inhibitor group was significantly reduced, the cell proliferation was enhanced, the apoptosis rate was reduced, the level of Ki67 protein was increased, and the level of cleaved caspase-3 was decreased (all P <0.05). FOXP1 is the target gene of miR-150. Compared with NC mimic group, the expression of FOXP1 protein in miR-150 mimic group was significantly reduced, the cell proliferation was reduced, the apoptosis rate was significantly increased, Ki67 protein level was decreased, and the level of cleaved caspase-3 was increased. Compared with miR-150 mimic + vector group, the expression of FOXP1 protein in miR-150 mimic + pcDNA-FOXP1 group was significantly increased, the cell proliferation was enhanced, the apoptosis rate was reduced, the level of Ki67 protein was increased, and the level of cleaved caspase-3 was decreased (all P <0.05). CONCLUSION LINC00174 promotes the proliferation of MM cells and inhibits cell apoptosis by regulating the miR-150/ FOXP1 axis.
Humans ; Apoptosis ; Caspase 3 ; Cell Line, Tumor ; Cell Proliferation ; Forkhead Transcription Factors ; Ki-67 Antigen ; MicroRNAs/genetics* ; Multiple Myeloma/pathology* ; Repressor Proteins ; RNA, Small Interfering ; RNA, Long Noncoding/genetics*

Multiple myeloma (MM) is a malignant proliferative disease of plasma cells. Bone marrow mesenchymal stem cells (MSC) play an important role in the progression of MM. Compared with normal donor derived MSC (ND-MSC), MM patients derived MSC (MM-MSC) exhibit abnormalities in genes, signaling pathways, protein expression levels and cytokines secreted by themselves. Moreover, the exosomes of MM-MSC can interact with the bone marrow microenvironment. The above reasons can lead to MM cell proliferation, chemoresistance, impaired osteogenic differentiation of MM-MSC, and affect the immunomodulatory capacity of MM patients. In order to further understand the pathogenesis and related influencing factors of MM, this paper reviews the latest research progress of MM-MSC.
Humans ; Multiple Myeloma/pathology* ; Osteogenesis ; Mesenchymal Stem Cells ; Cell Differentiation ; Bone Marrow/metabolism* ; Bone Marrow Cells/metabolism* ; Tumor Microenvironment

Daratumumab is the first CD38 monoclonal antibody drug approved for the treatment of patients with multiple myeloma. It can bind to CD38 expressed by tumor cells, inhibit tumor cell growth and induce myeloma cell apoptosis through a variety of immune-related mechanisms. Meanwhile, CD38 is also expressed in other cells, including regulatory T cells, regulatory B cells and myeloid-derived suppressor cells, which provides a theoretical basis for the treatment of hematological tumor diseases other than non-multiple myeloma diseases. This article reviews the research progress and application of this part.
Humans ; Multiple Myeloma/pathology* ; ADP-ribosyl Cyclase 1 ; Antibodies, Monoclonal/pharmacology* ; Hematologic Neoplasms/drug therapy*

Multiple myeloma (MM) is a common plasma cell malignancy, accounting for the second largest hematological malignancy. Proteasome inhibitors represented by bortezomib (BTZ) have been the main treatment for patients with newly diagnosed and relapsed or refractory myeloma in nearly two decades. Although BTZ has improved the prognosis of MM patients, MM remains incurable in most patients, mainly because MM cells become resistant to BTZ. This review is to better understand the mechanism of MM resistance to BTZ and explore possible new therapeutic strategies.
Humans ; Bortezomib/therapeutic use* ; Multiple Myeloma/pathology* ; Proteasome Inhibitors/pharmacology* ; Prognosis ; Plasma Cells/pathology* ; Drug Resistance, Neoplasm ; Antineoplastic Agents/pharmacology* ; Cell Line, Tumor

OBJECTIVE: To study the expression level of nicotinamide phosphoribosyltransferase (NAMPT) in multiple myeloma (MM), its relationship with clinical indicators, prognosis and potential role. METHODS: Immunohistochemical staining was used to detect the expression of NAMPT in bone marrow biopsies of patients with newly diagnosed multiple myeloma (NDMM) and patients with iron deficiency anemia (IDA) hospitalized during the same period. According to the median expression level of NAMPT, NDMM patients were divided into high expression group and low expression group. The correlation between NAMPT expression level and clinical baseline data was analyzed, and survival analysis was performed to evaluate the relationship between NAMPT expression level and prognosis. The GSE24080 and GSE19784 datasets were used to analyze the effect of NAMPT on the prognosis. Gene set enrichment analysis (GSEA) explored the possible mechanism of NAMPT involved in MM cell function. RESULTS: The mean staining intensity of NAMPT in bone marrow tissue of 31 NDMM patients was 0.007±0.002, and that of 10 IDA patients was 0.002±0.002 (P < 0.05). The median expression level of NAMPT was 0.0041 in NDMM patients, and the mean staining intensity of high expression group and low expression group was 0.007±0.005 and 0.002±0.001, respectively (P < 0.001). There were certain differences in lactate dehydrogenase (LDH), C-reactive protein (CRP) and ISS staging between high expression group and low expression group (P < 0.001), while no significant differences in other indicators. The overall response rate (ORR) of high expression group was significantly lower than that of low expression group (P < 0.001). The median survival time of patients in high expression group was significantly shorter than that in low expression group (P =0.024). The results of bioinformatics analysis showed that the event-free survival (EFS) rate and overall survival (OS) rate of low NAMPT group were both higher than high NAMPT group (P =0.037, P =0.009), and NAMPT was an independent prognostic factor for EFS and OS (P =0.006, P =0.020). GSEA suggested that NAMPT might affect MM cell function through mTORC1 signaling pathway. CONCLUSIONS The expression level of NAMPT in bone marrow of NDMM patients is significantly higher than that of IDA patients, and the high expression of NAMPT may be correlated with late ISS stage, and high level of LDH and CRP. Patients with high expression of NAMPT have worse response to bortezomib and survival time may be shorter. NAMPT may be involved in the occurrence and development of MM through mTORC1 signaling pathway.
Humans ; Multiple Myeloma/genetics* ; Bone Marrow/pathology* ; Nicotinamide Phosphoribosyltransferase ; Clinical Relevance ; Prognosis ; Mechanistic Target of Rapamycin Complex 1

OBJECTIVE: To establish a MM patient-derived tumor xenograft model (MM-PDX) in zebrafish, and to evaluate the anti-myeloma activity of indirubin-3'-monoxime(I3MO) using this model. METHODS: Zebrafish embryos 2 days after fertilization were transplanted with fluorescence labeled myeloma primary tumor cells, the survival of primary tumor cells in zebrafish was observed at 0,16 and 24 hours after cell injection. The zebrafish embryos after tumor cell transplantation were randomly divided into control group, BTZ treatment and I3MO treatment group. Before and 24 hours after treatment with BTZ and I3MO, the positive area with calcein or Dil in zebrafish were observed under fluorescence microscope to reflect the survival of tumor cells, and it was verified. RESULTS: MM patient derived tumor cells survived in zebrafish. The construction of MM-PDX was successful. Compared with control group, the fluo- rescence area of the BTZ and I3MO treatment groups in zebrafish were significantly decreased(P<0.05), and BTZ and I3MO significantly inhibited the survival of MM cells in zebrafish. CONCLUSION MM-PDX model was successfully established. Zebrafish model derived from tumor cells of MM patients can be used as a tool for drug screening of MM.
Animals ; Humans ; Bortezomib/therapeutic use* ; Cell Line, Tumor ; Disease Models, Animal ; Drug Evaluation, Preclinical ; Heterografts ; Multiple Myeloma/pathology* ; Xenograft Model Antitumor Assays ; Zebrafish