OBJECTIVE: To explore the construction method of a resistant multiple myeloma (MM) patient-derived xenotransplantation (PDX) model. METHODS: 1.0×10⁷ MM patient-derived mononuclear cells (MNCs), 2.0×10⁶ MM.1S cells and 2.0×10⁶ NCI-H929 cells were respectively subcutaneously inoculated into NOD.CB17-Prkdc^scid Il2rg^tm1/Bcgen (B-NDG) mice with a volume of 100 μl per mouse to establish mouse model. The morphologic, phenotypic, proliferative and genetic characteristics of PDX tumor were studied by hematoxylin-eosin staining, immunohistochemical staining (IHC), cell cycle analysis, flow cytometry and fluorescence in situ hybridization (FISH). The sensitivity of PDX tumor to bortezomib and anlotinib monotherapy or in combination was investigated through cell proliferation, apoptosis and in vitro and in vivo experiments. The effects of anlotinib therapy on tumor blood vessel and cell apoptosis were analyzed by IHC, TUNEL staining and confocal fluorescence microscope. RESULTS: MM PDX model was successfully established by subcutaneously inoculating primary MNCs. The morphologic features of tumor cells from MM PDX model were similar to those of mature plasma cells. MM PDX tumor cells positively expressed CD138 and CD38, which presented 1q21 amplification, deletion of Rb1 and IgH rearrangement, and had a lower proliferative activity than MM cell lines. in vitro, PDX, MM.1S and NCI-H929 cells were treated by bortezomib and anlotinib for 24 hours, respectively. Cell viability assay showed that the IC₅₀ value of bortezomib were 5 716.486, 1.025 and 2.775 nmol/L, and IC₅₀ value of anlotinib were 5 5107.337, 0.706 and 5.13 μmol/L, respectively. Anlotinib treatment increased the apoptosis of MM.1S cells (P < 0.01), but did not affect PDX tumor cells (P >0.05). in vivo, there was no significant difference in PDX tumor growth between bortezomib monotherapy group and control group (P >0.05), while both anlotinib monotherapy and anlotinib combined with bortezomib effectively inhibited PDX tumor growth (both P < 0.05). The vascular perfusion and vascular density of PDX tumor were decreased in anlotinib treatment group (both P < 0.01). The apoptotic cells in anlotinib treatment group were increased compared with those in control group (P < 0.05). CONCLUSION Bortezomib-resistant MM PDX model can be successfully established by subcutaneous inoculation of MNCs from MM patients in B-NDG mice. This PDX model, which retains the basic biological characteristics of MM cells, can be used to study the novel therapies.
Animals ; Bortezomib ; Humans ; Multiple Myeloma/pathology* ; Mice ; Apoptosis ; Drug Resistance, Neoplasm ; Cell Line, Tumor ; Xenograft Model Antitumor Assays ; Mice, Inbred NOD ; Disease Models, Animal ; Cell Proliferation ; Transplantation, Heterologous

OBJECTIVE: To analyze the significance of total vitamin D (tVD), total procollagen type I amino-terminal propeptide (tPINP) and β-CrossLaps (β-CTx) in the staging and prognosis of patients with multiple myeloma (MM). METHODS: A total of 54 patients with newly diagnosed MM admitted to the Second Affiliated Hospital of Fujian Medical University from 2020 to 2022 were selected as the observation group (MM group), and 50 healthy persons who underwent physical examinations in our hospital were selected as the control group. The expression levels of tVD, tPINP and β-CTx in the two groups were detected by chemiluminescence method. The differences in the expression levels of tVD, tPINP and β-CTx among MM patients at different ISS stages were analyzed. The expression levels of tVD, tPINP and β-CTx in MM patients with different levels of hemoglobin (Hb), serum calcium (Ca), creatinine (Crea), albumin (ALB), β₂-microglobulin (β₂-MG) and lactate dehydrogenase (LDH) were compared. The correlations between the expression levels of tVD, tPINP, β-CTx and the aforementioned clinical parameters were analyzed, respectively. The relationship between the expression levels of tVD, tPINP, β-CTx and the progression-free survival (PFS) of MM patients was analyzed. RESULTS: The expression level of tVD in the MM group was significantly lower than that in the control group (21.73±14.45 ng/ml vs 30.78±9.94 ng/ml, P =0.022). The expression level of β-CTx in the MM group was significantly higher than that in the control group (1.43±0.99 ng/ml vs 0.53±0.29 ng/ml, P =0.013). The tVD level in MM patients with ISS stage I-II was significantly higher than that of MM patients with ISS stage III (29.50±14.59 ng/ml vs 12.62±7.73 ng/ml, P =0.028), indicating that the higher the ISS stage, the lower the tVD level. The tPINP and β-CTx levels in MM patients with high Ca levels (>2.65 mmol/L) were significantly higher than those in patients with low Ca levels (≤2.65 mmol/L) (P =0.016, P =0.021). The tVD level of MM patients was positively correlated with the ALB level (r =0.570), tPINP was positively correlated with Ca and β₂-MG levels (r =0.791,r =0.673), and β-CTx was positively correlated with tPINP level (r =0.616). The PFS of the low tVD expression group was significantly lower than that of the high tVD expression group (P =0.041). CONCLUSION The expression level of tVD is decreased in MM patients, which can be used as an indicator to evaluate the disease stage and prognosis of the patients. The β-CTx expression level is increased in MM patients. tPINP and β-CTx may be correlated with clinical symptoms such as osteolytic lesions and renal function changes in MM patients.
Humans ; Multiple Myeloma/pathology* ; Procollagen/blood* ; Vitamin D/blood* ; Prognosis ; Peptide Fragments/blood* ; Collagen Type I/blood* ; Female ; Male ; Middle Aged ; Aged ; Neoplasm Staging

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: To investigate the effect of signals mediated by activated CD28 in promoting survival of multiple myeloma (MM) cells and metabolic fitness and its possible mechanism. METHODS: The expression of CD28 on 4 MM cell lines (XG2, XG1, RPMI 8226 and U266) was determined by flow cytometry. Two cell lines with the highest or lowest CD28 expression were selected. The proliferation, cell cycle, migration and apoptosis of MM cells in vitro were determined in medium containing high glucose concentration or CD28 agonist monoclonal antibody with different bioassays. shRNA interference assay was used to knock down the expression of CD28 on U266 cells. Then, the effect of activated CD28 on glucose uptake rate and drug resistance in MM cells were analyzed using fluorescent glucose analogues (2-NBDG). The expression of Glut1/4, HkII and Fasn was determined with real time quantitative PCR. RESULTS: Flow cytometry analysis showed that all the four tested MM cell lines expressed CD28 and U266 cells had the highest positive rate. The results of in vitro experiment showed that CD28 activation could significantly up-regulate the expression of Glut4 and HkII, promote MM cell metabolic remodeling, enhance 2-NBDG/glucose uptake, increase energy metabolism, thereby elevating cell proliferation and migration abilities, leading to an increase in the number of cells in S- and G₂-phases. Meanwhile, activated CD28 subsequently up-regulated resistance of MM cells to bortezomib or dexamethasone. CONCLUSION MM cells express high levels of CD28 abnormally, and activation of CD28 can promote up-regulation of glucose uptake in MM cells, thereby promoting cell proliferation and enhancing drug resistance.
Humans ; Multiple Myeloma/pathology* ; CD28 Antigens/metabolism* ; Cell Proliferation ; Cell Line, Tumor ; Apoptosis ; Glucose/metabolism* ; Glucose Transporter Type 4/metabolism* ; Glucose Transporter Type 1

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

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

Humans ; Herpesvirus 4, Human ; Epstein-Barr Virus Infections/complications* ; Multiple Myeloma/complications* ; Lymphoma, Large B-Cell, Diffuse/pathology*

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*