Tetrahydroisoquinoline reduces angiogenesis by interacting myeloma cells with HUVECs mediated by extracellular vesicles.

Multiple myeloma (MM) is a neoplastic condition resulting from the uncontrolled expansion of B-cell-derived plasma cells. The importance of angiogenesis in MM development has also been demonstrated. Extracellular vesicles (EVs) have vital functions in interactions between neighboring cells, such as angiogenesis. The objective of this in vitro study was to examine the transfection and angiogenesis effects of MM-EVs on endothelial cells (ECs) upon treatment with Tetrahydroisoquinoline (THIQ) as a bioactive organic compound derivative from isoquinoline. Following treatment of multiple myeloma cells (U266) with THIQ, MM-EVs were harvested and transmigrated to human umbilical vein endothelial cells (HUVEC) in a co-culture model. EVs transmigration was traced by flow cytometry. Correspondingly, the expression of angiogenic genes and/or proteins in U266 cells and HUVECs was measured by RT-PCR and ELISA methods. Likewise, the proliferation and migration of HUVECs treated with THIQ-treated MM-EVs were visualized and estimated by performing both tube formation and scratch wound healing methods. Surprisingly, the anti-angiogenic effect of THIQ-treated MM-EVs was evident by the decreased expression of CD34, VEGFR2, and IL-6 at the mRNA and/or protein levels after internalization of MM-EVs in HUVEC. Finally, tube formation and scratch wound healing experiments showed inhibition of HUVEC cell proliferation and migration by THIQ-treated MM-EVs compared to control MM-EVs. MM-EVs derived from THIQ-treated myeloma cells (U266) inhibited angiogenesis in HUVECs. This phenomenon is coordinated by the internalized THIQ-treated MM-EVs in HUVECs, and ultimately the reduction of angiogenic factors and inhibition of tube formation and scratch wound healing.

Dihydrolipoamide dehydrogenase (DLD) is a novel molecular target of bortezomib.

Proteasome inhibitors (PIs), such as bortezomib and calfizomib, were backbone agents in the treatment of multiple myeloma (MM). In this study, we investigated bortezomib interactors in MM cells and identified dihydrolipoamide dehydrogenase (DLD) as a molecular target of bortezomib. DLD catalyzes the oxidation of dihydrolipoamide to form lipoamide, a reaction that also generates NADH. Our data showed that bortezomib bound to DLD and inhibited DLD's enzymatic function in MM cells. DLD knocked down MM cells (DLD-KD) had decreased levels of NADH. Reduced NADH suppressed assembly of proteasome complex in cells. As a result, DLD-KD MM cells had decreased basal-level proteasome activity and were more sensitive to bortezomib. Since PIs were used in many anti-MM regimens in clinics, we found that high expression of DLD correlated with inferior prognosis of MM. Considering the regulatory role of DLD in proteasome assembly, we evaluated DLD targeting therapy in MM cells. DLD inhibitor CPI-613 showed a synergistic anti-MM effect with bortezomib in vitro and in vivo. Overall, our findings elucidated DLD as an alternative molecular target of bortezomib in MM. DLD-targeting might increase MM sensitivity to PIs.

Factors Associated With Survival Among Patients With Multiple Myeloma in Northeastern Tanzania.

PURPOSE: This study sought to delineate the clinical, laboratory, and imaging characteristics during multiple myeloma (MM) diagnosis, outline the treatment modalities administered, and ascertain the survival rates among patients with MM over a comprehensive 5-year span in Tanzania. METHODS: This retrospective cohort study investigated patients diagnosed with MM at the Cancer Care Clinic, Kilimanjaro Christian Medical Centre, between January 2017 and June 2022. Demographic data, clinical profiles, and survival outcomes were collected. The study employed the Kaplan-Meier method to determine overall survival (OS) and survival rates, supported by univariate analysis and a multivariate Cox regression model with significance of P < .05. RESULTS: In this study of 76 patients with MM, bone pain was the most common complaint (76.3%), and patients were age typically older than 50 years (82.5%). Laboratory tests showed frequent abnormalities, such as anemia (51.3%) and hypercalcemia (23.9%). Most patients were at stage III according to Durie Salmon Staging (82.7%), with imaging revealing various bone abnormalities. The median OS was 18.0 months, with 46.1% of patients passing away during the study period. Factors linked to shorter survival included anemia, renal failure, and bone involvement. Infection was the primary cause of death among these patients. The presenting complaint of bone pain significantly affected survival outcomes. CONCLUSION: This study provides a comprehensive understanding of MM within the Sub-Saharan African context, highlighting age-related disparities in diagnosis, predominant presenting symptoms like bone pain, factors contributing to delayed diagnoses, and the impact on survival rates. The findings underscore the critical need for early recognition, improved diagnostics, and tailored interventions to enhance outcomes for patients with MM in this region.

Prognostic value of the "dynamic" R2-ISS in patients with multiple myeloma undergoing anti-CD38 antibody-based triplet therapies.

To retrospectively analyze whether the second revision of the international staging system (R2-ISS) influenced prognosis at treatment initiation in patients with multiple myeloma (MM) receiving anti-CD38 antibody-based triplet treatments. High-risk chromosomal abnormalities were examined from diagnosis to treatment initiation and considered positive if detected once. R2-ISS was recalculated at the initiation of treatment and defined as "dynamic R2-ISS." Data from 150 patients who underwent the defined treatments were analyzed. The median progression-free survival (PFS) was 19.5 months, and the median overall survival (OS) was 36.5 months. Dynamic R2-ISS significantly stratified prognoses for both PFS and OS. The median PFS for patients with dynamic R2-ISS IV was 3.3 months, and the median OS was 11.7 months, indicating extremely poor outcomes. Although the Revised International Staging System (R-ISS) calculated at the initiation of treatment significantly stratified treatment outcomes, the patients classified as R-ISS could be further stratified by R2-ISS to provide better prognostic information. Dynamic R2-ISS showed potential as a prognostic tool in patients with MM who are treated with anti-CD38 antibody-based triplet therapies.

Super enhancer acquisition drives expression of oncogenic PPP1R15B that regulates protein homeostasis in multiple myeloma.

Multiple myeloma is a hematological malignancy arising from immunoglobulin-secreting plasma cells. It remains poorly understood how chromatin rewiring of regulatory elements contributes to tumorigenesis and therapy resistance in myeloma. Here we generate a high-resolution contact map of myeloma-associated super-enhancers by integrating H3K27ac ChIP-seq and HiChIP from myeloma cell lines, patient-derived myeloma cells and normal plasma cells. Our comprehensive transcriptomic and phenomic analyses prioritize candidate genes with biological and clinical implications in myeloma. We show that myeloma cells frequently acquire SE that transcriptionally activate an oncogene PPP1R15B, which encodes a regulatory subunit of the holophosphatase complex that dephosphorylates translation initiation factor eIF2α. Epigenetic silencing or knockdown of PPP1R15B activates pro-apoptotic eIF2α-ATF4-CHOP pathway, while inhibiting protein synthesis and immunoglobulin production. Pharmacological inhibition of PPP1R15B using Raphin1 potentiates the anti-myeloma effect of bortezomib. Our study reveals that myeloma cells are vulnerable to perturbation of PPP1R15B-dependent protein homeostasis, highlighting a promising therapeutic strategy.

Size-Exclusion Chromatography: A Path to Higher Yield and Reproducibility Compared to Sucrose Cushion Ultracentrifugation for Extracellular Vesicle Isolation in Multiple Myeloma.

Small extracellular vesicles (EVs) play a pivotal role in intercellular communication across various physiological and pathological contexts. Despite their growing significance as disease biomarkers and therapeutic targets in biomedical research, the lack of reliable isolation techniques remains challenging. This study characterizes vesicles that were isolated from conditioned culture media (CCM) sourced from three myeloma cell lines (MM.1S, ANBL-6, and ALMC-1), and from the plasma of healthy donors and multiple myeloma patients. We compared the efficacy, reproducibility, and specificity of isolating small EVs using sucrose cushion ultracentrifugation (sUC) vs. ultrafiltration combined with size-exclusion chromatography (UF-SEC). Our results demonstrate that UF-SEC emerges as a more practical, efficient, and consistent method for EV isolation, outperforming sUC in the yield of EV recovery and exhibiting lower variability. Additionally, the comparison of EV characteristics among the three myeloma cell lines revealed distinct biomarker profiles. Finally, our results suggest that HBS associated with Tween 20 improves EV recovery and preservation over PBS. Standardization of small EV isolation methods is imperative, and our comparative evaluation represents a significant step toward achieving this goal.

Measurable residual disease (MRD) dynamics in multiple myeloma and the influence of clonal diversity analyzed by artificial intelligence.

Minimal residual disease (MRD) assessment is a known surrogate marker for survival in multiple myeloma (MM). Here, we present a single institution's experience assessing MRD by NGS of Ig genes and the long-term impact of depth of response as well as clonal diversity on the clinical outcome of a large population of MM patients; 482 MM patients at the University of California, San Francisco (UCSF) diagnosed from 2008 to 2020 were analyzed retrospectively. MRD assessment was performed by NGS. PFS curves were plotted by the Kaplan-Meier method. In the newly diagnosed group, 119 of 304, achieved MRD negativity at the level of 10-6 at least once. These patients had a prolonged PFS versus patients who were persistently MRD positive at different levels (p > 0.0001). In the relapsed disease group, 64 of 178 achieved MRD negativity at 10-6, and PFS was prolonged versus patients who remained MRD positive (p = 0.03). Three categories of MRD dynamics were defined by artificial intelligence: (A) patients with ≥3 consistently MRD negative samples, (B) patients with continuously declining but detectable clones, and (C) patients with either increasing or a stable number of clones. Groups A and B had a more prolonged PFS than group C (p < 10-7). Patients who were MRD positive and had not yet relapsed had a higher clonal diversity than those patients who were MRD positive and had relapsed. MRD dynamics can accurately predict disease evolution and drive clinical decision-making. Clonal Diversity could complement MRD assessment in the prediction of outcomes in MM.

Lys-63-specific deubiquitinase BRCC36 enhances the sensitivity of multiple myeloma cells to lenalidomide by inhibiting lysosomal degradation of cereblon.

Multiple myeloma (MM) is the second most common hematological tumor in adults. Immunomodulatory drugs (IMiDs), such as thalidomide and lenalidomide (Len), are effective drugs for the treatment of multiple myeloma. Len can recruit IKZF1 and IKZF3 to cereblon (CRBN), a substrate receptor of the cullin 4-RING E3 ligase (CRL4), promote their ubiquitination and degradation, and finally inhibit the proliferation of myeloma cells. However, MM patients develop resistance to IMiDs over time, leading to disease recurrence and deterioration. To explore the possible approaches that may enhance the sensitivity of IMiDs to MM, in this study, we used the proximity labeling technique TurboID and quantitative proteomics to identify Lys-63-specific deubiquitinase BRCC36 as a CRBN-interacting protein. Biochemical experiments demonstrated that BRCC36 in the BRISC complex protects CRBN from lysosomal degradation by specifically cleaving the K63-linked polyubiquitin chain on CRBN. Further studies found that a small-molecule compound SHIN1, which binds to BRISC complex subunit SHMT2, can upregulate CRBN by elevating BRCC36. The combination of SHIN1 and Len can further increase the sensitivity of MM cells to IMiDs. Therefore, this study provides the basis for the exploration of a possible strategy for the SHIN1 and Len combination treatment for MM.

[Correlation analysis of polyclonal plasma cell proportion in the bone marrow with clinical characteristics of patients with newly diagnosed multiple myeloma].

Objective: To explore the correlation of bone marrow polychonal plasma cell proportion (pPC% ) and clinical features in newly diagnosed multiple myeloma (NDMM) patients. Methods: A retrospective analysis of 317 patients with NDMM admitted to Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology from January 2018 to January 2023 was performed. The results of the pPC% in all patients were clear. The relationship between the pPC% and clinical characteristics was analyzed. Results: A total of 317 patients were included, comprising 180 males and 137 females. The median age at diagnosis was 61 (26-91) years, and 55.8% were 60 years or older. The pPC% in the bone marrow of patients with NDMM was different in the DS, International Staging System (ISS), and revised ISS (R-ISS) stages (P=0.002, 0.010, and 0.049, respectively), whereas no statistical difference in pPC% was observed among patients with different FISH risk stratigrams (P=0.971). The correlation coefficient between pPC% and hemoglobin (HGB) at the first diagnosis in patients was 0.211 (P<0.01). The correlation coefficients with serum calcium, serum creatinine, M protein level, and ß(2)-microglobulin were -0.141, -0.120, -0.181, and -0.207, respectively, and the results of the significance test were P=0.012, 0.033, 0.004, and 0.002, respectively, indicating a negative correlation. Compared with the patients with a pPC% of ≥2.5%, the group of patients with a pPC% of <2.5% had significantly higher levels of light chain, serum calcium, serum creatinine, M protein, and ß(2)-microglobulin at the initial diagnosis (P<0.05) ; lower HGB level (P<0.001) ; and a higher proportion of patients in ISS stage Ⅲ (P=0.034) . Conclusion: In this study, the pPC% in patients with NDMM was associated with clinical features of good prognosis, including higher HGB, lower serum calcium, serum creatinine, M protein quantity, ß(2)-microglobulin, light chain involvement, lower proportion of advanced disease (DS stage and ISS stage Ⅲ), and clinical features showing lower tumor burden.

[Multiple myeloma with t (8;14) and t (11;14) and extramedullary infiltration of multiple organs].

A 69-year-old man presented with lumbago and was diagnosed with multiple myeloma (IgD-λ type, R-ISS stage II) with bone-destructive lesions in the lumbar spine and sacrum. Chromosome analysis showed t (8;14)(q24;q32) and t (11;14)(q13;q32). Treatment with daratumumab, lenalidomide, and dexamethasone resulted in partial response, but the disease relapsed, with a copy number increase in t (11;14) and abnormal amplification of the 1q21 region. The patient was treated for CMV enteritis, and was admitted to the hospital due to sudden abdominal pain. Gastrointestinal perforation was diagnosed by CT scan showing free air and wall thickening in the small intestine. Emergency surgery was performed, and the tumors in the perforated area were positive for CCND1 but negative for MYC on immunostaining. The patient's general condition did not improve after the surgery and he died. Pathological autopsy revealed extramedullary infiltration of multiple organs in addition to the small intestine. Extramedullary infiltration is thought to be caused by clonal evolution, and further research is warranted to clarify its pathogenesis and establish effective therapeutic strategies in high-risk patients.

Monoclonal gammopathy of clinical signifi cance with osteosclerotic lesions - a case report and a literature review.

INTRODUCTION: Multiple myeloma is a common plasma cell neoplasia usually accompanied by the formation of osteolytic foci, whereas osteosclerotic myeloma is a very rare form of plasma cell dyscrasia. When osteosclerotic myeloma is detected, osteosclerotic foci are usually part of the POEMS syndrome. Osteosclerotic myeloma without other manifestations of the POEMS syndrome is an unusual finding. CASE DESCRIPTION: In a 46-year-old woman, osteosclerotic changes of the temporoparietal region caused soft tissue induration over this lesion, which initiated further investigation. Imaging studies subsequently showed multiple osteosclerotic foci in the skull. Examination of blood proteins revealed 8 g/L of IgG-lambda monoclonal immunoglobulin, subclass IgG1. In search of the cause of the osteosclerotic changes, FDG-PET/CT was performed, which revealed no FDG accumulation, i.e., no other tumor (breast or stomach cancer). Low-dose CT showed irregular bone structure, but not significant osteolytic or osteosclerotic foci. To map the extent of osteosclerotic changes, NaF-PET/CT imagination followed, which revealed multiple spots with high fluoride accumulation. A parietal bone biopsy showed osteosclerosis with minor clonal plasma cell infiltration. Trepanobioptic bone marrow sampling revealed an infiltration of bone marrow with atypical plasma cells in 8%. Flow-cytometric examination of bone marrow showed 0,37% of plasma cells, however predominantly (91%) clonal with lambda expression. MRI of the brain identified asymptomatic meningeal thickening. There was no evidence of POEMS syndrome in the patient; thus, we concluded the diagnosis as monoclonal gammopathy of clinical significance with osteosclerosis which was previously termed osteosclerotic multiple myeloma. CONCLUSION: Monoclonal gammopathy of clinical significance (MGCS) with osteosclerotic skeletal changes, documented on CT and multiple foci with intensive osteoneogenesis, documented on NaF-PET/CT without evidence of POEMS syndrome, is an extremely rare form of plasma cell dyscrasia. This publication documents the unique clinical manifestations of IgG-lambda type plasma cell proliferation without signs of POEMS syndrome and the role of NaF-PET/CT imaging. Classification of this disease as MGSC with osteosclerotic manifestations is more consistent with the indolent nature of the disease with a significantly better prognosis, compared with multiple myeloma.

Clotrimazole inhibits growth of multiple myeloma cells in vitro via G0/G1 arrest and mitochondrial apoptosis.

Patients with multiple myeloma (MM) experience relapse and drug resistance; therefore, novel treatments are essential. Clotrimazole (CTZ) is a wide-spectrum antifungal drug with antitumor activity. However, CTZ's effects on MM are unclear. We investigated CTZ's effect on MM cell proliferation and apoptosis induction mechanisms. CTZ's effects on MM.1S, NCI- H929, KMS-11, and U266 cell growth were investigated using Cell Counting Kit-8 (CCK-8) assay. The apoptotic cell percentage was quantified with annexin V-fluorescein isothiocyanate/7-amino actinomycin D staining. Mitochondrial membrane potential (MMP) and cell cycle progression were evaluated. Reactive oxygen species (ROS) levels were measured via fluorescence microscopy. Expression of apoptosis-related and nuclear factor (NF)-κB signaling proteins was analyzed using western blotting. The CCK-8 assay indicated that CTZ inhibited cell proliferation based on both dose and exposure time. Flow cytometry revealed that CTZ decreased apoptosis and MMP and induced G0/G1 arrest. Immunofluorescence demonstrated that CTZ dose-dependently elevated in both total and mitochondrial ROS production. Western blotting showed that CTZ enhanced Bax and cleaved poly ADP-ribose polymerase and caspase-3 while decreasing Bcl-2, p-p65, and p-IκBα. Therefore, CTZ inhibits MM cell proliferation by promoting ROS-mediated mitochondrial apoptosis, inducing G0/G1 arrest, inhibiting the NF-κB pathway, and has the potential for treating MM.

Skull base plasmacytoma in young patients aged below 40 years: Radiological perspectives and clinical outcomes.

BACKGROUND: Plasmacytoma of the skull base is a rare manifestation of plasma cell neoplasm with only a few cases documented in literature involving young adults. Plasmacytoma can be an isolated solitary lesion or a secondary manifestation of multiple myeloma (MM). In this study, we report the clinical and radiological characteristics, management, and outcomes of patients under the age of 40 who presented with skull base plasmacytoma and associated neurological manifestations. Additionally, we share our experience in treating a rare case of skull base plasmacytoma diagnosed during pregnancy, in which the patient exhibited a favorable response to myeloma treatment initiated after delivery. CASE SERIES: Four patients were identified, comprising one pregnant female and three male patients, with a median age of 36 years (range 33-37 years). The main presenting symptoms were headache, dizziness, and cranial nerve palsy. All patients received underwent systemic myeloma therapy and radiotherapy with three patients also underwent autologous stem cell transplantation (ASCT). Notably, all patients achieved complete remission. CONCLUSION: Skull base plasmacytoma represents a rare manifestation of plasma cell neoplasms, underscoring the importance of considering it in the differential diagnosis of skull base lesions to ensure early intervention and avoid potential serious complications. Throughout our series, the cornerstone of therapy involved radiotherapy, systemic myeloma therapy, and ASCT, all of which elicited a favorable response in every case.

Phase I study of TQB3602, an oral proteasome inhibitor, in relapsed and refractory multiple myeloma.

OBJECTIVE: TQB3602 is a novel orally bioavailable proteasome inhibitor. This study is the first-in-human phase I clinical trial to evaluate the safety, tolerability, pharmacokinetics, and preliminary efficacy of TQB3602 in relapsed/refractory multiple myeloma (RRMM). METHODS: This is a multicenter phase I clinical trial consisting of the 3+3 dose-escalation phase and dose expansion phase. Patients with MM who have received ≥2 prior antimyeloma therapies were enrolled. TQB3602 is administered at a dose of 0.5~7mg on days 1, 8, 15 in 28-day cycle. RESULTS: Twenty-five RRMM patients who relapsed or failed ≥2 lines of therapies were enrolled in the dose escalation phase. Two patients in the 7.0 mg dose group developed dose-limiting toxicity events (one with grade 2 peripheral neuropathy [PN] complicated by pain and one with diarrhea and abdominal pain), leading to a maximum tolerated dose of 6.0 mg. Any-grade adverse events (AEs) occurred in 24 (96.0%) patients, while grade ≥3 AEs occurred in 13 (52.0%). The most common grade ≥3 AEs was anemia (6, 24.0%). The incidence rate of PN was 16% with no grade ≥3 PN occurred. TQB3602 was rapidly absorbed, resulting in a time-to-plasma peak concentration of 0.8-1.5 h. The mean half-life was approximately 82 h. The AUClast and Cmax were approximately 1.9 times higher on day 15 than on day 1. Among 22 response-evaluable patients, 63.7% achieved stable disease or better. CONCLUSIONS: TQB3602 is well tolerated, with a favorable neurotoxicity profile, and has shown preliminary efficacy in patients with RRMM. The anticipated therapeutic dose was 6 mg and was adopted for an ongoing dose-expansion phase.

LILRB4 regulates multiple myeloma development through STAT3-PFKFB1 pathway.

Although multiple myeloma (MM) responds well to immunotherapeutic treatment, certain portions of MM are still unresponsive or relapse after immunotherapy. Other immune molecules are needed for the immunotherapy of MM. Here, we revealed that leukocyte immunoglobulin-like receptor B4 (LILRB4) was highly expressed in multiple myeloma cell lines and patient samples and that the expression of LILRB4 was adversely correlated with the overall survival of MM patients. Knockdown of LILRB4 efficiently delayed the growth of MM cells both in vitro and in vivo. Mechanistically, IKZF1 transactivated LILRB4 expression to trigger the downstream of STAT3-PFKFB1 pathways to support MM cell proliferation. Blockade of LILRB4 signaling by blocking antibodies can effectively inhibit MM progression. Our data show that targeting LILRB4 is potentially an additional therapeutic strategy for the immunotherapeutic treatment of MM.

Bone marrow fibrosis in newly diagnosed multiple myeloma and its correlation with clinicopathological factors.

BACKGROUND: Bone marrow fibrosis (BMF) severely impacts both the quality of life and the efficacy of diagnostic procedures. However, the correlation between BMF and clinicopathological features, cytogenetic changes, and prognosis of newly diagnosed multiple myeloma (NDMM) remains unclear. This study determined the incidence, patient characteristics, and clinical outcomes of patients with NDMM with BMF. METHODS: The clinical data, histological features, and clinical outcomes of patients with NDMM were collected. Reticular fiber staining was performed on the enrolled cases, and the degree of reticular fiber overgrowth was graded. Patients with MF-2 and MF-3 were classified as the BMF+ group, and those with MF-0 and MF-1 were classified as the BMF- group, and BMF incidence was calculated. The differences in clinical data, histological features, and clinical outcomes between the BMF+ group and the BMF- group were compared. RESULTS: A consecutive series of 146 patients with NDMM were included. The incidence of MF-0, MF-1, MF-2, and MF-3 was 7.53% (11/146), 34.93% (51/146), 51.37% (75/146), and 6.16% (9/146), respectively. The incidence of BMF-MF-2 and MF-3-was 57.53% (84/146). A significant correlation was identified between the pattern of infiltration and BMF (P < 0.001). In the BMF- group, the distribution of cases with interstitial, nodular, and diffuse infiltration of plasma cells was 16 (25.8%), 21 (33.9%), and 25 (40.3%), respectively. Conversely, in the BMF+ group, these values for interstitial, nodular, and diffuse tumor cells were 9 (10.7%), 15 (17.9%), and 60 (71.4%). Furthermore, BMF was associated with a diffuse infiltration pattern. The overall survival (OS) of the BMF+ group (39.1 months; 95% confidence interval [CI]: 34.0-44.3) was lower than that of the BMF- group (45.4 months; 95% CI: 39.5-51.3), but there was no significant difference between the two groups (P = 0.221). Univariate and multivariate analyses showed that the BMF+ status was not associated with OS in patients with NDMM (P = 0.381 and P = 0.748, respectively). CONCLUSIONS: Our findings suggest that BMF is linked to a diffuse infiltration pattern, and its occurrence is not related to the prognosis of patients with NDMM, providing a basis for further exploring the BMF value in NDMM diagnosis and treatment.