From spear to trident: Upgrading arsenal of CAR-T cells in the treatment of multiple myeloma

Multiple myeloma (MM), marked by abnormal proliferation of plasma cells and production of monoclonal immunoglobulin heavy or light chains in the majority of patients, has traditionally been associated with poor survival, despite improvements achieved in median survival in all age groups since the introduction of novel agents. Survival has significantly improved with the development of new drugs and new treatment options, such as chimeric antigen receptor T-cell therapy (CAR-T), which have shown promise and given new hope in MM therapy. CARs are now classified as first-, second-, and third-generation CARs based on the number of monovalent to trivalent co-stimulatory molecules incorporated into their design. The scope of this review was relatively narrow because it was mainly about a comparison of the literature on the clinical application of CAR-T therapy in MM. Thus, our goal is to provide an overview of the new advances of CAR-T cells in the cure of MM, so in this review we looked at the progress of the clinical use of CAR-T cells in MM to try to provide a reference for their clinical use when managing MM.

Integrating p53-associated genes and infiltrating immune cell characterization as a prognostic biomarker in multiple myeloma

Background

Tumor genetic anomalies and immune dysregulation are pivotal in the progression of multiple myeloma (MM). Accurate patient stratification is essential for effective MM management, yet current models fail to comprehensively incorporate both molecular and immune profiles.

Methods

We examined 776 samples from the MMRF CoMMpass database, employing univariate regression with LASSO and CIBERSORT algorithms to identify 15 p53-related genes and six immune cells with prognostic significance in MM. A p53-TIC (tumor-infiltrating immune cells) classifier was constructed by calculating scores using the bootstrap-multicox method, which was further validated externally (GSE136337) and through ten-fold internal cross-validation for its predictive reliability and robustness.

Results

The p53-TIC classifier demonstrated excellent performance in predicting the prognosis in MM. Specifically, patients in the p53low/TIChigh subgroup had the most favorable prognosis and the lowest tumor mutational burden (TMB). Conversely, those in the p53high/TIClow subgroup, with the least favorable prognosis and the highest TMB, were predicted to have the best anti-PD1 and anti-CTLA4 response rate (40 %), which can be explained by their higher expression of PD1 and CTLA4. The three-year area under the curve (AUC) was 0.80 in the total sample.

Conclusions

Our study highlights the potential of an integrated analysis of p53-associated genes and TIC in predicting prognosis and aiding clinical decision-making in MM patients. This finding underscores the significance of comprehending the intricate interplay between genetic abnormalities and immune dysfunction in MM. Further research into this area may lead to the development of more effective treatment strategies.

Molecular Pathogenesis of Multiple Myeloma: Clinical Implications

Multiple myeloma is a malignancy of bone-marrow-localized, isotype-switched plasma cells that secrete a monoclonal immunoglobulin and cause hyperCalcemia, Anemia, Renal failure, and lytic Bone disease. It is preceded, often for decades, by a relatively stable monoclonal gammopathy lacking these clinical and malignant features. Both conditions are characterized by the presence of types of immunoglobulin heavy gene translocations that dysregulate a cyclin D family gene on 11q13 (CCND1), 6p21 (CCND3), or 12q11 (CCND2), a maf family gene on 16q23 (MAF), 20q11 (MAFB), or 8q24 (MAFA), or NSD2/FGFR3 on 4p16, or the presence of hyperdiploidy. Subsequent loss of function of tumor suppressor genes and mutations activating MYC, RAS, NFkB, and cell cycle pathways are associated with the progression to malignant disease.

The preclinical discovery and clinical development of ciltacabtagene autoleucel (Cilta-cel) for the treatment of multiple myeloma

INTRODUCTION

Despite remarkable therapeutic advances over the last two decades, which have resulted in dramatic improvements in patient survival, multiple myeloma (MM) is still considered an incurable disease. Therefore, there is a high need for new treatment strategies. Genetically engineered/redirected chimeric antigen receptor (CAR) T cells may represent the most compelling modality of immunotherapy for cancer treatment in general, and MM in particular. Indeed, unprecedented response rates have led to the recent approvals of the first two BCMA-targeted CAR T cell products idecabtagene-vicleucel ('Ide-cel') and ciltacabtagene-autoleucel ('Cilta-Cel') for the treatment of heavily pretreated MM patients. In addition, both are emerging as a new standard-of-care also in earlier lines of therapy.

AREAS COVERED

This article briefly reviews the history of the preclinical development of CAR T cells, with a particular focus on Cilta-cel. Moreover, it summarizes the newest clinical data on Cilta-cel and discusses strategies to further improve its activity and reduce its toxicity.

EXPERT OPINION

Modern next-generation immunotherapy is continuously transforming the MM treatment landscape. Despite several caveats of CAR T cell therapy, including its toxicity, costs, and limited access, prolonged disease-free survival and potential cure of MM are finally within reach.

Novel cuproptosis-related lncRNAs can predict the prognosis of patients with multiple myeloma

Background

Cuproptosis-related long-stranded non-coding RNAs (lncRNAs) have several implications for the prognosis of multiple myeloma (MM). This research aimed to construct a prognostic risk model for MM patients and explore the potential signaling pathways in the risk group.

Methods

Cuproptosis-related lncRNAs were obtained from the co-expression analysis of cuproptosis-related genes and lncRNAs. Subsequently, twelve cuproptosis-related lncRNAs were selected to construct a prognostic risk model of MM patients by the least absolute shrinkage and selection operator (LASSO) regression. Then, the clinical data of these patients were randomly divided into the training group and the testing group. Next, patients were divided into the low- and high-risk groups according to the median risk score. The Kaplan-Meier survival analysis was performed to clarify the prognostic differences between risk subtypes. Besides, the Cox analysis was conducted to identify whether the risk score can be used as an independent prognostic factor. In addition, the receiver operating characteristic (ROC) curve analysis and the concordance index (C-index) curve analysis were performed to elucidate the value of risk score as a prognostic indicator. Finally, the differential risk analysis and functional enrichment analysis were carried out to identify the potential signaling pathways in the low- and high-risk groups.

Results

The results demonstrated that the overall survival (OS) of patients in the high-risk group was shorter than that in the low-risk group. There were significant differences in the expression of genes in MM patients between the high- and low-risk groups. The Gene Ontology (GO) analysis results showed that the differentially expressed risk-related genes (DERGs) were mainly concentrated on the collagen-containing extracellular matrix. According to the Kyoto Encyclopedia of Genes and Genomes (KEGG) analysis results, the DERGs may be related to the neuroactive ligand-receptor interaction and mitogen-activated protein kinase (MAPK) signaling pathway, indicating that they may be involved in the progression of tumors.

Conclusions

The findings of this study suggest that cuproptosis-related lncRNAs may be effective biomarkers for predicting the prognosis of MM patients, which is anticipated to contribute to the improvement of clinical outcomes.

Progressive multifocal leukoencephalopathy in multiple myeloma: a case report of a patient with SARS-CoV-2 infection and an updated systematic literature review

BACKGROUND

Progressive multifocal leukoencephalopathy (PML) is a demyelinating disease of the central nervous system caused by a reactivation of the human polyomavirus 2 (HPyV-2, previously known as JCV) in immunosuppressed individuals. Few cases of PML have been described in multiple myeloma (MM) patients.

METHODS

We described a case of PML in a patient with MM with fatal worsening that occurred during SARS-CoV-2 infection. We also performed a literature review to update the 16 cases series of MM patients with PML already collected until April 2020.

RESULTS

A 79-year-old female patient with refractory IgA lambda MM in Pomalidomide- Cyclophosphamide-Dexamethasone regimen developed gradual lower limbs and left arm paresis along with a decreased consciousness 3.5 years after the MM diagnosis. Symptoms developed shortly after the recognition of hypogammaglobulinemia. After SARS-CoV-2 infection, her neurological status quickly worsened until she deceased. MRI features and JCV-positive PCR on CSF confirmed the PML diagnosis. Our literature review adds sixteen clinical cases of PML in MM published between May 2020 and March 2023 to the 16 cases already collected in the previously published review by Koutsavlis.

DISCUSSION

PML has been increasingly described in MM patients. It remains questionable if the HPyV-2 reactivation is determined by the severity of MM itself, by the effect of drugs or by a combination of both. SARS-CoV-2 infection may have a role in worsening PML in affected patients.

Microangiopathy in multiple myeloma: a case of carfilzomib-induced secondary thrombotic microangiopathy successfully treated with plasma exchange and complement inhibition

BACKGROUND

Thrombotic microangiopathy (TMA) is a potentially organ and life-threatening condition affecting patients with multiple myeloma (MM). Cases of proteasome inhibitor-induced TMA and specifically carfilzomib-induced TMA have been rarely reported and standards for diagnostic workup and treatment are not available.

CASE PRESENTATION

We describe a case of a male MM patient under salvage therapy including proteasome inhibitor carfilzomib following chemotherapy and autologous stem cell transplantation. The patient then developed acute kidney injury with clinical and laboratory signs of TMA. Hemodialysis became necessary and treatment with plasma exchange was initiated followed by therapy with C5 complement inhibitor eculizumab which led to amelioration of kidney function and hemolysis parameters.

CONCLUSION

We report a patient with suspected proteasome inhibitor-induced secondary thrombotic microangiopathy that has been successfully treated with plasma exchange and eculizumab, a monoclonal antibody targeting complement factor C5.

Network pharmacology- and molecular docking-based investigation of the therapeutic potential and mechanism of daucosterol against multiple myeloma

Background

Some studies have shown that daucosterol has potential anti-tumor activity, but its therapeutic effect on multiple myeloma (MM) has not been reported. This study aimed to evaluate the therapeutic effect daucosterol against MM and explore its possible mechanism through network pharmacology.

Methods

We collected daucosterol and approved drugs for MM, and their potential target profiles were obtained. We used 2 major methods to collect the gene sets related to the physiological process of MM. Based on the protein-protein interaction (PPI) network in the STRING database, the correlation between the therapeutic targets of daucosterol and MM-related genes was calculated by using the random walk with restart (RWR) algorithm to systematically evaluate the therapeutic potential of daucosterol for MM. On this basis, through intersection analysis, the potential targets of daucosterol in treating MM were identified, and the signaling pathways were mined. Furthermore, the key targets were identified. Finally, the regulatory relationship between the predicted daucosterol and potential targets was verified by molecular docking method, and the interaction mode between daucosterol and key targets was analyzed.

Results

A total of 13 approved drugs reported to treat MM were retrieved from the DrugBank database. A total of 35 potential targets of daucosterol were obtained, including 8 known targets and 27 newly predicted targets. In the PPI network, the target of daucosterol was significantly correlated with MM-related genes, indicating that it has therapeutic potential for MM. A total of 18 therapeutic targets for MM were obtained, which were significantly enriched in the FoxO signaling pathway, prostate cancer, the PI3K-Akt signaling pathway, insulin resistance, the AMPK signaling pathway, and pathways related to the regulation of TP53. The core targets were HSP90AA1, MDM2, GSK3B, AKT3, PRKAA1, and PRKAB1. Molecular docking suggested that daucosterol had potential direct regulatory effects on 13 of the 18 predicted targets.

Conclusions

This study highlights the use of daucosterol as a promising therapeutic drug for MM treatment. These data provide new insights into the potential mechanism of daucosterol in the treatment of MM, which may provide references for subsequent research and even the clinical treatment.

A novel human multiple myeloma cell line with a 1q21 gain genetic abnormality and CKS1B overexpression

Background

Multiple myeloma (MM) is an incurable hematologic malignancy mainly due to its cytogenetic abnormalities. Therefore, it is important to establish permanent malignant MM cell lines as tools to develop more effective therapies.

Methods

Pleural effusion cells of a 70-year-old patient was collected to establish the CZ2 cell line. Characterization of CZ2 was determined with nephelometry, flow cytometry, fluorescence in situ hybridization (FISH), and chromosomal microarray analysis (CMA). Western blotting analysis was adopted to determine protein expression. Cell viability was measured by the 3-(4,5-dimethyl thiazol-2-yl)-2,5-diphenyl tetrazolium bromide (MTT) assay.

Results

We established and characterized a new MM cell line, CZ2. Using nephelometry and flow cytometry, cells with typical plasma cell morphology but not classical plasma cell phenotype were found to be non-immunoglobulin-secretary cells. FISH analysis of cells revealed a unique characteristic, namely, that there was only gain of the 1q21 region (1q21+). No other common cytogenetic abnormalities in MM, such as deletion of 17p (17p-), deletion of 13q (13q-), or translocation of immunoglobulin heavy chain (IgH), were observed. In addition, the original cell line maintains its single cytogenetic abnormality. Meanwhile, we observed through western blotting that CDC28 protein kinase regulatory subunit 1B (CKS1B), an adverse prognostic gene located in the 1q21 region, was highly expressed in CZ2. Knockdown of CKS1B reduced cell viability and also increased the levels of cleaved-poly(ADP-ribose) polymerase (cleaved-PARP) and cleaved-caspase3.

Conclusions

CZ2 provides a suitable material for cellular and molecular studies of MM with only a 1q21 abnormality. This cell line is characterized by a gain of 1q21, and the high expression of CKS1B is an important model for studies of myeloma cell growth and drug resistance during therapy.

Multidisciplinary tumor board analysis: validation study of a central tool in tumor centers

The established standard to ensure state-of-the-art cancer treatment is through multidisciplinary tumor boards (TBs), although resource- and time-intensive. In this validation study, the multiple myeloma (MM)-TB was reexamined, aiming to validate our previous (2012-2014) results, now using the TB data from March 2020 to February 2021. We assessed MM-TB protocols, physicians' documentation, patient, disease, remission status, progression-free survival (PFS), and overall survival (OS) as left-truncated survival times. Moreover, TB-adherence, level of evidence according to grade criteria, time requirements, study inclusion rates, and referral satisfaction were determined. Within a 1-year period, 312 discussed patients were documented in 439 TB protocols. Patient and disease characteristics were typical for comprehensive cancer centers. The percentages of patients discussed at initial diagnosis (ID), with disease recurrence or in need of interdisciplinary advice, were 39%, 28%, and 33%, respectively. Reasons for the MM-TB presentation were therapeutic challenges in 80% or staging/ID-defining questions in 20%. The numbers of presentations were mostly one in 73%, two in 20%, and three or more in 7%. The TB adherence rate was 93%. Reasons for non-adherence were related to patients' decisions or challenging inclusion criteria for clinical trials. Additionally, we demonstrate that with the initiation of TBs, that the number of interdisciplinarily discussed patients increased, that TB-questions involve advice on the best treatment, and that levels of compliance and evidence can be as high as ≥ 90%. Advantages of TBs are that they may also improve patients', referrers', and physicians' satisfaction, inclusion into clinical trials, and advance interdisciplinary projects, thereby encouraging cancer specialists to engage in them.

The potential of glutamine metabolism-related long non-coding RNAs (lncRNAs) as prognostic biomarkers in multiple myeloma patients

Background

Glutamine (Gln) metabolism has been confirmed as an important fuel in cancer metabolism. This study aimed to uncover potential links of Gln with long non-coding RNAs (lncRNAs) and the prognostic value of Gln-associated lncRNAs in multiple myeloma (MM) patients.

Methods

The RNA-seq expression profile and corresponding clinical data of gastric cancer obtained from Gene Expression Omnibus (GEO) database. Unsupervised consensus clustering was used to cluster MM samples based on Gln-associated lncRNAs. The overall survival (OS), biological pathways, and immune microenvironment were compared in different subtypes. Differential analysis was utilized to identify differentially expressed lncRNAs (DElncRNAs) in different subtypes. A risk model was constructed based on DElncRNAs by using Cox regression, least absolute shrinkage and selection operator (LASSO), and the stepAIC algorithm.

Results

We screened 50 Gln-associated lncRNAs and identified 3 molecular subtypes (clust1, clust2, and clust3) based on lncRNA expression profiles. Clust3 subtype showed the worst prognosis and highest enrichment of Gln metabolism pathway. Angiogenesis, epithelial-mesenchymal transition (EMT), and cell cycle-related pathways were relatively activated in clust3. Then, we identified 11 prognostic DElncRNAs for constructing the risk model. The MM samples were divided into high- and low-risk groups with distinct prognosis according to the risk score. The risk score was significantly associated with cell cycle and infiltration of many immune cells.

Conclusions

This study characterized the role of Gln-associated lncRNAs in Gln metabolism contributing for tumor-related pathways and immune microenvironment in MM patients. The 11 lncRNAs in the risk model may serve as potential targets for exploring the mechanism of Gln metabolism or serve as potential biomarkers for MM prognosis.

Is RDW a clinically relevant prognostic factor for newly diagnosed multiple myeloma? A systematic review and meta-analysis

Background

Multiple myeloma (MM) is an incurable plasma cell malignancy. Red cell distribution width (RDW) is a prognostic marker in various diseases, solid tumors, and hematologic neoplasms, but its prognostic significance in MM is controversial. In this study, we aimed to assess the relationship between RDW and the clinical prognosis of MM patients through a meta-analysis.

Methods

Relevant literature were retrieved from PubMed, Embase, and Web of Science databases according to PRISMA guideline. All relevant parameters were extracted and combined for statistical analysis. The effect size was presented as hazard ratio (HR)/odds ratio (OR) and 95% confidence interval (CI). HR/OR > 1 in MM patients with high RDW suggested a worse prognosis. Heterogeneity test evaluation was performed using Cochran's Q test and I2 statistics. A P_{heterogeneity} < 0.10 or I² > 50% suggested significant heterogeneity. P < 0.05 was considered statistically significant. Statistical analysis was performed using Stata 12.0 software.

Results

8 articles involving 9 studies with 1165 patients were included in our meta-analysis. Our results suggested that elevated RDW is significantly associated with poor prognosis in MM (OS: HR = 1.91, 95%CI: 1.48–2.46; PFS: HR = 2.87, 95% CI: 2.02–4.07). A significant correlation was not found between RDW and International Staging System (ISS) staging (ISS III VS ISS I-II: OR:1.53; 95%CI:0.97–2.42).

Conclusion

Our results suggested that RDW is a robust predictor of newly diagnosed MM outcomes.

Cellular membrane-based vesicles displaying a reconstructed B cell maturation antigen for multiple myeloma therapy by dual targeting APRIL and BAFF

Excessive secretion of cytokines (such as APRIL and BAFF) in the bone marrow microenvironment (BMM) plays an essential role in the formation of relapsed or refractory multiple myeloma (MM). Blocking the binding of excessive cytokines to their receptors is becoming a promising approach for MM therapy. Here, we proposed a strategy of engineering cell membrane-based nanovesicles (NVs) to reconstruct B cell maturation antigen (BCMA), a receptor of APRIL and BAFF, to capture excess APRIL/BAFF in BMM as a bait protein. Our results showed that reconstructed BCMA expressed on the membrane of NVs (Re-BCMA-NVs) retained the ability of binding to soluble and surface-bound APRIL/BAFF in BMM. Consequently, Re-BCMA-NVs blocked the activation of the NF-κB pathway, downregulating the expression of anti-apoptosis genes and cell cycle-related genes, and hence inhibiting MM cell survival. Importantly, Re-BCMA-NVs showed a synergistic anti-MM effect when administrated together with bortezomib (BTZ) in vitro and in vivo. Our NVs targeting multiple cytokines in cancer microenvironment provides a solution to enhance sensitivity of MM cells to BTZ-based therapy. STATEMENT OF SIGNIFICANCE: Excessive APRIL and BAFF is reported to promote the survival of MM cell and facilitate the formation of resistance to bortezomib therapy. In this study, we bioengineered cell membrane derived reconstructed BCMA nanovesicles (Re-BCMA-NVs) to capture both soluble and cell-surface APRIL and BAFF. These NVs inhibited the activation of NF-κB pathway and thus inhibit the survival of MM cells in 2D, 3D and subcutaneous mouse tumor models. Importantly, Re-BCMA-NVs showed a synergistic anti-MM effect when administrated together with bortezomib in vitro and in vivo. Taken together, our NVs targeting multiple cytokines in cancer microenvironment provides a solution to enhance sensitivity of MM cells to bortezomib-based therapy.

Knockdown of lncRNA AL928768.3 inhibits multiple myeloma cell proliferation by inducing cell cycle arrest in G0/G1 phase

Background

Multiple myeloma (MM) is a B-lymphocyte-derived malignancy. It ranks as the second most common hematological malignancy, with relatively high morbidity and mortality. However, the molecular mechanisms of MM occurrence and development remain elusive. This study found that long non-coding RNA AL928768.3 (lncRNA AL) was abnormally expressed in MM samples. However, the effect and molecular mechanism of lncRNA AL on the occurrence and development of MM remains unclear.

Methods

Bone marrow fluids of MM patients (n=54) and volunteers (n=13) were collected and CD138⁺ cells were isolated. The expression level of lncRNA AL in MM cells was detected by quantitative real-time polymerase chain reaction (qRT-PCR), and the correlation between the expression level of lncRNA AL and the clinicopathological features of patients was analyzed. Lentiviral vectors targeting lncRNA AL knockdown were constructed and transfected into cells. After transfection, the effects of lncRNA AL knockdown on MM cell proliferation and the cell cycle were detected by the CCK-8 assay, clone formation assay, and flow cytometry. The effect of lncRNA AL knockdown on MM cell cycle-related proteins was detected by Western blot. In addition, tumorigenicity experiments were performed in nude mice to detect the effect of lncRNA AL knockdown on MM cell proliferation in vivo.

Results

LncRNA AL was highly expressed in MM patient samples and cell lines, and was significantly correlated with the disease stage of patients. Knockdown of lncRNA AL significantly inhibited the proliferation and colony formation of MM cells and induced cell cycle arrest in G0/G1 phase. Western blot analysis showed that knockdown of lncRNA AL significantly inhibited the expression of CDK2 and cyclin D1 and promoted the expression of cyclin suppressor p21. Knockdown of lncRNA AL significantly inhibited the proliferation of MM cells in nude mice.

Conclusions

LncRNA AL was highly expressed in MM patients. Knockdown of this gene significantly inhibited the proliferative ability of MM cells and induced cell cycle arrest in G0/G1 phase. Therefore, lncRNA AL may be a novel biological target molecule for the early diagnosis, treatment, and prognostic evaluation of MM patients.

Clinical exercise therapy program with multiple myeloma patients: Impacts on feasibility, adherence and efficacy

PURPOSE

Multiple myeloma (MM) is a severe hemato-oncological disease with high mortality and increasing incidence rate. Since evidence on exercise therapy in MM patients remains limited, this study examines feasibility, adherence, and efficacy based on real-life data from an oncologic care structure.

METHODS

A data evaluation of MM patients who participated in the oncologic exercise and movement therapy (OTT) at the Cologne University Hospital between 2012 and 2019 was conducted. The patient flow was incrementally reduced to four cohorts, intention-to-treat cohort (ITTC), safety cohort (SC), adherence cohort (AC), and efficacy cohort (EC). Cohorts were evaluated descriptively and by means of correlation analysis as well as group and time comparisons.

RESULTS

Thirty patients registered at the OTT between 2012 and 2019 (ITTC). The SC (N = 26) attended exercise therapy on average about one session per week over a period of 8 months. One-third dropped out within 3 months. In the AC (N = 15), BMI at baseline exhibited a strong and very significant negative correlation with exercise adherence. In the EC (N = 8), a significant improvement in physical functioning and a tendency towards significance in fatigue reduction between two measurement points was observed. No adverse events were documented.

CONCLUSIONS

The present observatory study reveals safety and feasibility while indicating adherence and efficacy of exercising MM patients under real-life therapy circumstances. Found obstacles to exercising as well as improvements in questionnaire scale scores need to be further examined in confirmatory study designs.

Comparison between tumour metabolism derived from 18F-FDG PET/CT and accurate cytogenetic stratification in newly diagnosed multiple myeloma patients

Background

¹⁸F-fluorodeoxyglucose positron emission tomography integrated with computed tomography (¹⁸F-FDG PET/CT) is a useful tool for baseline staging in newly diagnosed multiple myeloma (MM) but also for prognostic stratification. This monocentric retrospective study aimed at examining the relation between baseline tumour metabolism assessed by ¹⁸F-FDG PET/CT and linear predictor (LP) score, a new cytogenetic stratification score.

Methods

From March 2012 to March 2019, 57 patients with newly diagnosed MM addressed to our institution for baseline ¹⁸F-FDG PET/CT were included. LP score was determined on systematic iliac crest bone marrow samples. Obtained on CD138-sorted bone marrow plasma cells, this recent composite cytogenetic stratification is a 6-marker based weighted score using fluorescence in situ hybridization (FISH) ± single nucleotide polymorphism (SNP) arrays. We compared quantitative metabolic parameters and LP score using a Kruskal-Wallis test and visual suspicion of diffuse bone marrow involvement (DBI; based on hepatic background as threshold of positivity) and cytogenetic data using a Chi-squared test.

Results

The distribution of total metabolic tumour volume (TMTV) and total lesion glycolysis (TLG) values among the three LP score categories was almost stochastic, with no significant association (P=0.70). Additionally, no significant association between TMTV/TLG and any of the six cytogenetic abnormalities included in LP score calculation. A significant association was found between visual high suspicion of DBI and LP score (P=0.036), and between this visual parameter and the presence of 1q gain (P=0.049).

Conclusions

There is no significant association between quantitative metabolic parameters assessed with ¹⁸F-FDG PET/CT and LP score in patients with newly diagnosed MM, suggesting a potential complementarity of these biomarkers for prognostic stratification. A significant association was found between high visual suspicion of DBI and LP score.

In vivo quantitative assessment of therapeutic response to bortezomib therapy in disseminated animal models of multiple myeloma with [18F]FDG and [64Cu]Cu-LLP2A PET

Background

Multiple myeloma (MM) is a disease of cancerous plasma cells in the bone marrow. Imaging-based timely determination of therapeutic response is critical for improving outcomes in MM patients. Very late antigen-4 (VLA4, CD49d/CD29) is overexpressed in MM cells. Here, we evaluated [¹⁸F]FDG and VLA4 targeted [⁶⁴Cu]Cu-LLP2A for quantitative PET imaging in disseminated MM models of variable VLA4 expression, following bortezomib therapy.

Methods

In vitro and ex vivo VLA4 expression was evaluated by flow cytometry. Human MM cells, MM.1S-CG and U266-CG (C: luciferase and G: green fluorescent protein), were injected intravenously in NOD-SCID gamma mice. Tumor progression was monitored by bioluminescence imaging (BLI). Treatment group received bortezomib (1 mg/kg, twice/week) intraperitoneally. All cohorts (treated, untreated and no tumor) were longitudinally imaged with [¹⁸F]FDG (7.4–8.0 MBq) and [⁶⁴Cu]Cu-LLP2A (2–3 MBq; Molar Activity: 44.14 ± 1.40 MBq/nmol) PET, respectively.

Results

Flow cytometry confirmed high expression of CD49d in U266 cells (> 99%) and moderate expression in MM.1S cells (~ 52%). BLI showed decrease in total body flux in treated mice. In MM.1S-CG untreated versus treated mice, [⁶⁴Cu]Cu-LLP2A localized with a significantly higher SUV_mean in spine (0.58 versus 0.31, p < 0.01) and femur (0.72 versus 0.39, p < 0.05) at week 4 post-tumor inoculation. There was a four-fold higher uptake of [⁶⁴Cu]Cu-LLP2A (SUV_mean) in untreated U266-CG mice compared to treated mice at 3 weeks post-treatment. Compared to [⁶⁴Cu]Cu-LLP2A, [¹⁸F]FDG PET detected treatment-related changes at later time points.

Conclusion

[⁶⁴Cu]Cu-LLP2A is a promising tracer for timely in vivo assessment of therapeutic response in disseminated models of MM.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13550-021-00840-4.

Association of VLA4, 5, 6 and PSGL1 expression levels with engraftment in autologous HPSC transplantation in multiple myeloma patients

The most promising therapy for leukemia is hematopoietic stem cell transplantation. Engraftment of HPSCs mainly depends on some factors such as adhesion molecules, including VLAs. This study tried to delineate the relationship between HPSCs engraftment and expression level of PSGL1 and VLA4, 5, and 6 genes in candidate MM patients for autologous bone marrow transplantation. Firstly, the CD 34+ HPSCs were collected from multiple myeloma (MM) patients after five days of G-CSF therapy through apheresis processes. Then, the patients were categorized into two groups of good and bad prognosis depending on engraftment time (Less or more than 18 days). Followingly, the expression of PSGL1 and VLA4, VLA5, and VLA6 genes were assessed by the qRT-PCR technique in each patient. Finally, the correlation between the genes and engraftment time was investigated to determine the prognostic role of each gene on HPSCs transplantation. Our findings demonstrated that there is a significant correlation between VLA4 (P=< 0.0001) and 5 (P = 0.005) levels and HPSCs engraftment time. As the higher levels of VLA4 and 5, the shorter time HPSCs engraftment occurs. In contrast, there was no significant correlation between VLA6 (P = 0.2) and PSGL1 (P = 0.3) genes levels and engraftment time. So that, the patients with a good prognosis had a higher level of VLA4 and VLA5, but no relation was found between VLA6 and PSGL1. It is concluded that VLA4 and VLA5 expression could be considered a significant prognostic factor for HPSC transplantation.

Quantitative whole-body MR imaging for assessment of tumor burden in patients with multiple myeloma: correlation with prognostic biomarkers

Background

To assess the quantification of tumor burden in multiple myeloma (MM) patients using whole-body magnetic resonance imaging (MRI) and to identify the correlation between MRI parameters and prognostic biomarkers.

Methods

We retrospectively analyzed 95 newly diagnosed MM patients treated at our hospital from June 2018 to March 2020. All patients underwent whole-body MRI examination, including diffusion-weighted whole-body imaging with background body signal suppression (DWIBS), modified Dixon chemical-shift imaging (mDIXON), and short TI inversion recovery (STIR) sequences. The MRI presentation was used to determine MM infiltration patterns and calculate apparent diffusion coefficient (ADC) and a fat fraction (FF). The one-way ANOVA and Kruskal-Wallis test were used to compare the differences of these values between DS, ISS, and R-ISS stages in different MM infiltration patterns. Spearman correlation test was used for correlation analysis of ADC and FF against prognostic biomarkers, and two independent sample t-test was used to evaluate the differences of ADC and FF in different free light-chain ratio groups.

Results

The MRI presentation was classified into normal pattern (36 patients; 37.9%), diffuse (27 patients; 28.4%), and focal (32 patients; 33.7%) infiltration patterns. Statistically significant ADC and FF differences between different DS, ISS, and R-ISS stages were observed in normal/diffuse infiltration patterns but not in focal infiltration patterns. The ADC and FF of the normal/diffuse infiltration pattern showed correlations with hemoglobin, β2-microglobulin, bone marrow plasma cells, flow cytometry of bone marrow cells, and serum monoclonal protein. In contrast, ADC in focal infiltration patterns was negatively correlated with β2-microglobulin and C-reactive protein. The FF of patients with a normal/diffuse infiltration pattern was higher in the low free light-chain ratio group than that in the high free light-chain ratio group (P=0.023).

Conclusions

Our observations indicate that quantitative whole-body functional MRI examination may serve as an effective complement to imaging diagnosis based on morphology and provide further information on the tumor burden of patients with MM.

Discovery of 3,5-dimethylisoxazole derivatives as novel, potent inhibitors for bromodomain and extraterminal domain (BET) family

Bromodomain and extra-terminal (BET) is a promising therapeutic target for various hematologic cancers. We used the BRD4 inhibitor compound 13 as a lead compound to develop a variety of compounds, and we introduced diverse groups into the position of the compound 13 orienting toward the ZA channel. A series of compounds (14-23, 38-41, 43, 47-49) bearing triazolopyridazine motif exhibited remarkable BRD4 protein inhibitory activities. Among them, compound 39 inhibited BRD4(BD1) protein with an IC₅₀ of 0.003 μM was superior to lead compound 13. Meanwhile, compound 39 possess activity, IC₅₀ = 2.1 μM, in antiproliferation activity against U266 cancer cells. On the other hand, compound 39 could arrest tumor cells into the G0/G1 phase and induce apoptosis, which was consistent with its results in inhibiting cell proliferation. Biological and biochemical data suggest that BRD4 protein might be a therapeutic target and that compound 39 is an excellent lead compound for further development.

Two cases of carfilzomib-induced thrombotic microangiopathy successfully treated with Eculizumab in multiple myeloma

BACKGROUND

Treatment with proteasome inhibitors like carfilzomib in patients with multiple myeloma (MM) can induce thrombotic microangiopathy (TMA) characterized by neurological symptoms, acute kidney injury, hemolysis and thrombocytopenia. Successful treatment with the monoclonal antibody eculizumab was described for these patients, but reports of ideal management and definitive treatment protocols are lacking.

CASE PRESENTATION

The first case describes a 43-years-old IgG-kappa-MM patient that developed TMA during the first course of carfilzomib-lenalidomide-dexamethasone (KRd) consolidation after autologous stem cell transplantation (ASCT). In the second case, a 59-years-old IgG-kappa-MM patient showed late-onset TMA during the fourth and last cycle of elotuzumab-KRd consolidation within the DSMM XVII study of the German study group MM (DSMM; clinicalTrials.gov Identifier: NCT03948035). Concurrently, he suffered from influenza A/B infection. Both patients had a high TMA-index for a poor prognosis of TMA. Therapeutically, in both patients plasma exchange (TPE) was initiated as soon as TMA was diagnosed. In patient #1, dialysis became necessary. For both patients, only when the complement inhibitor eculizumab was administered, kidney function and blood values impressively improved.

CONCLUSION

In this small case series, two patients with MM developed TMA due to carfilzomib treatment (CFZ-TMA), the second patient as a late-onset form. Even though TMA could have been elicited by influenza in the second patient and occurred after ASCT in both patients, with cases of TMA post-transplantation in MM being described, a relation of TMA and carfilzomib treatment was most likely. In both patients, treatment with eculizumab over two months efficiently treated TMA without recurrence and with both patients remaining responsive months after TMA onset. Taken together, we describe two cases of TMA in MM patients on carfilzomib-combination treatment, showing similar courses of this severe adverse reaction, with good responses to two months of eculizumab treatment.

The Outcome of Six Patients with COVID-19 Infection and Multiple Myeloma

No abstract, as A letter to the Editor.

Preclinical Development of Near-Infrared-Labeled CD38-Targeted Daratumumab for Optical Imaging of CD38 in Multiple Myeloma

PURPOSE

Cluster of differentiation 38 (CD38) is a promising therapeutic target in multiple myeloma (MM) patients and has resulted in the development of several CD38 immunotherapies. Current methods to evaluate CD38 expression in the preclinical setting include ex vivo flow cytometry and immunohistochemistry, which can be cumbersome and do not give whole-body information. In vivo imaging technologies such as positron emission tomography rely on decay of radioisotopes, limiting the number of molecular interactions observed at any given time point. Here, we demonstrate the use of near-infrared (NIR) fluorescence imaging for spatiotemporal monitoring of CD38 expression in preclinical MM using the anti-CD38 daratumumab (DARA) conjugated to the NIR fluorophore IRDye800CW (DARA-IRDye800).

PROCEDURES

Stability studies with human serum and binding assays with human myeloma cells were performed with DARA-IRDye800. Immunocompromised mice with intra- and extramedullary tumors (n = 5/group) were administered with DARA-IRDye800 for in vivo imaging up to 7 days after injection. Ex vivo biodistribution and flow cytometry studies were performed to validate in vivo imaging results. A separate therapy study was performed in mice with intramedullary tumors that were treated and not treated with DARA at a therapeutic dose (n = 7/group). DARA-IRDye800 was administered for subsequent in vivo and ex vivo imaging in both cohorts of mice.

RESULTS

DARA-IRDye800 maintained stability and had high affinity for CD38 (K_D = 3.5 ± 0.05 nM). DARA-IRDye800 demonstrated a 5- and 18-fold increase in contrast in tumor-bearing regions of mice with extra- and intramedullary MM. Finally, mice treated with therapeutic doses of DARA and imaged with DARA-IRDye800 showed an 11-fold decrease in fluorescence intensities in vivo compared with untreated controls.

CONCLUSIONS

Our studies establish DARA-IRDye800 as a promising contrast agent for preclinical evaluation of CD38 expression and for further investigating myeloma engraftment and kinetics in relation to anti-CD38 therapies.

Design, synthesis and biological evaluation of novel (E)-N-phenyl-4-(pyridine-acylhydrazone) benzamide derivatives as potential antitumor agents for the treatment of multiple myeloma (MM)

A series of novel (E)-N-phenyl-4-(pyridine-acylhydrazone) benzamide derivatives were designed, synthesized, and evaluated for their anti-proliferative activity against two different human cancer cell lines and one human normal cell line. Compound 8b had the best anti-proliferative activity (IC₅₀ = 0.12 ± 0.09 μM, RPMI8226 cells) than the other compounds. And compound 8b had lower toxicity than imatinib. Flow cytometry analysis showed that compound 8b could arrest the cell cycle at the G0/G1 phase, and induce apoptosis of RPMI8226 cells by promoting mitochondrial ROS release, thereby effectively inhibiting cell proliferation. Our findings provided a promising lead compound 8b for further structural optimization and will be instructive for the discovery of more potent antitumor drugs with high selectivity and low toxicity.

B cell maturation antigen (BCMA)-based immunotherapy for multiple myeloma

Introduction: B cell maturation antigen (BCMA) contributes to MM pathophysiology and is a target antigen for novel MM immunotherapy. Complete responses have been observed in heavily pretreated MM patients after treatment with BCMA antibody-drug conjugates (ADC), chimeric antigen receptor T, and bi-specific T cell engagers (BiTE®). These and other innovative BCMA-targeted therapies transform the treatment landscape and patient outcome in MM. Areas covered: The immunobiological rationale for targeting BCMA in MM is followed by key preclinical studies and available clinical data on efficacy and safety of therapies targeting BCMA from recent phase I/II studies. Expert opinion: BCMA is the most selective MM target antigen, and BCMA-targeted approaches have achieved high responses even in relapse and refractory MM as a monotherapy. Long-term follow-up and correlative studies using immuno-phenotyping and -sequencing will delineate mechanisms of overcoming the immunosuppressive MM bone marrow microenvironment to mediate additive or synergistic anti-MM cytotoxicity. Moreover, they will delineate cellular and molecular events underlying the development of resistance underlying relapse of disease. Most importantly, targeted BCMA-based immunotherapies used earlier in the disease course and in combination (adoptive T cell therapy, mAbs/ADCs, checkpoint and cytokine blockade, and vaccines) have great promise to achieve long-term disease control and potential cure.

Plasmacytoma as a cause of small bowel obstruction in a virgin abdomen in a patient with multiple myeloma: a case report

Background

Multiple myeloma is a hematological malignancy that classically results in an abnormal clonal proliferation of plasma cells in the bone marrow. Extramedullary disease in the setting of multiple myeloma, referred to as secondary extramedullary plasmacytoma, is found in 7–17% of cases of multiple myeloma at the time of diagnosis and can involve any organ system. Small bowel obstruction is a rare but important gastrointestinal manifestation of multiple myeloma that should be considered in patients with multiple myeloma who present with concerning abdominal symptoms.

Case presentation

We present the case of a 52-year-old African-American man with a history of deep venous thrombosis (he is on anticoagulation) and pathologic fracture secondary to multiple myeloma diagnosed 4 months prior to our encounter. He presented with abdominal pain, constipation, nausea, and vomiting. An abdominal X-ray showed distended bowel loops concerning for bowel obstruction and a contrast-enhanced computed tomography scan of his abdomen and pelvis showed a 5.4 cm soft tissue mass involving a loop of distal ileum. He underwent laparoscopic exploration of his abdomen with small bowel resection and primary anastomosis for a small intussusception. He had an uneventful postoperative course and was discharged on postoperative day 6.

Conclusions

Multiple myeloma has myriad presentations. Gastrointestinal involvement, although rare, can manifest as small bowel obstruction for which early recognition and appropriate surgical management are key to improving outcome. Intussusception is the most common mechanism of obstruction from extramedullary plasmacytoma causing small bowel obstruction and this has been seen in five of six case reports, including this case. It is important to recognize and consider the risks of immunosuppression, venous thromboembolism, and malnutrition in the surgical management of gastrointestinal complications of multiple myeloma.

Pulmonary function abnormalities are common in patients with multiple myeloma and are independently associated with worse outcome

Pre-existing pulmonary disease may affect treatment choices, toxicity, and survival of patients with multiple myeloma (MM). However, data on the prognostic value of pulmonary function tests (PFTs) in myeloma patients' outcome, at the time of initial assessment of newly diagnosed patients, are scarce. Here, we prospectively performed PFTs in 121 newly diagnosed MM patients, before initiation of treatment, and we evaluated possible associations of lung function with their outcomes. Fifty-four patients (44.63%) had either obstructive or restrictive pulmonary function defects, even among those not reporting a history of lung disease. The survival was significantly worse in those with obstructive pulmonary defect (median OS 32.8 months) vs. those with restrictive (median OS 52.5 months) or normal lung function (median not reached, 3-year survival 76%) (p = 0.013), independently of other myeloma-related factors. Forced vital capacity (FVC) (lt) (p = 0.012), forced expiratory volume in 1 s (FEV1) (lt) (p = 0.018), peak expiratory flow (PEF) (lt/min) (p = 0.008), carbon monoxide diffusion capacity (DLCO) (p = 0.012), and expiratory/inspiratory pressures (Pe) (kPa) (p = 0.032)/(Pi) (kPa) (p = 0.023) were significantly associated with OS. Myeloma-related factors associated with survival included ISS stage (p = 0.008), hypercalcemia (p = 0.064), and high-risk cytogenetics (p = 0.004). In the multivariate analysis, only the presence of high-risk cytogenetics and presence of either or both PEF and DLCO < 65% of predicted were independent prognostic factors. We conclude that PEF and DLCO could be useful in the initial assessment of newly diagnosed MM patients as significant predictors of survival. Further research is needed to evaluate if respiratory screening should be included in the routine initial evaluation of myeloma patients, despite the presence or absence of respiratory symptoms or abnormal clinical respiratory examination.

Chidamide, a novel histone deacetylase inhibitor, inhibits multiple myeloma cells proliferation through succinate dehydrogenase subunit A

Most patients with multiple myeloma (MM) would finally relapse despite the fact that initial MM may turn to remission by conventional chemotherapy. Current chemotherapy regimens have limited effect on relapse MM patients. As a new histone deacetylase inhibitor, chidamide has been used in malignancy treatment. However, it is still unknown if chidamide can be used in MM. Here, by RNA sequencing, succinate dehydrogenase subunit A (SDHA) was screened to be the key molecule modulated by chidamide. SDHA was downregulated in MM patients and the expression of SDHA had negative correlation with the severity of MM. In vitro, chidamide inhibited proliferation and invasion of MM cells, and this effect vanished after knocking down SDHA. Lenalidomide and low dose of bortezomib had synergistic effect with chidamide, and similarly this effect was attenuated by SDHA siRNA. Moreover, chidamide decreased the production of reaction oxygen species (ROS) via SDHA. In a word, by targeting the key molecule SDHA, chidamide may represent a promising strategy in MM treatment.

Extracellular vesicles of multiple myeloma cells utilize the proteasome inhibitor mechanism to moderate endothelial angiogenesis

Bone marrow microenvironment is known to support angiogenesis, thus contributing to progression of multiple myeloma (MM). Bortezomib, a proteasome inhibitor (PI) widely used in MM treatment, has anti-angiogenic activity. Extracellular vesicles (EVs), shedding from cell surface, serve as mediators in cell-to-cell communication. We have hypothesized that MM cells (MMCs) treated with bortezomib generate EVs that could diminish angiogenesis, thus limiting MM progression. In the present study, EVs were obtained from MMCs (RPMI-8226), untreated (naïve) or pre-treated with bortezomib. EVs were outlined using NanoSight, FACS, protein arrays and proteasome activity assays. The impact of MMC-EVs on endothelial cell (EC) functions was assessed, employing XTT assay, Boyden chamber and Western blot. A high apoptosis level (annexin V binding 70.25 ± 16.37%) was observed in MMCs following exposure to bortezomib. Compared to naïve EVs, a large proportion of bortezomib-induced EVs (Bi-EVs) were bigger in size (> 300 nm), with higher levels of annexin V binding (p = 0.0043).They also differed in content, presenting with increased levels of pro-inflammatory proteins, reduced levels of pro-angiogenic growth factors (VEGFA, PDGF-BB, angiogenin), and displayed lower proteasome activity. Naïve EVs were found to promote EC migration and proliferation via ERK1/2 and JNK1/2/3 phosphorylation, whereas Bi-EVs inhibited these functions. Moreover, Bi-EVs appeared to reduce EC proteasome activity. EVs released from apoptotic MMCs following treatment with bortezomib can promote angiogenesis suppression by decreasing proliferation and migration of EC. These activities are found to be mediated by specific signal transduction pathways.

Multiple myeloma presenting as cutaneous leukocytoclastic vasculitis and eosinophilia disclosing a T helper type 1/T helper type 2 imbalance: a case report

Background

Multiple myeloma is a very heterogeneous disease comprising a number of genetic entities that differ from each other in their evolution, mode of presentation, response to therapy, and prognosis. Due to its more chronic nature and cumulative toxicities that patients develop from multiple lines of treatments, a number of symptoms are associated with multiple myeloma. However, the mechanisms responsible for the relationship between these symptoms and multiple myeloma currently remain unclear.

Case presentation

An 85-year-old Japanese woman exhibited the rare presentation of multiple myeloma (immunoglobulin kappa chain type) with leukocytoclastic vasculitis and eosinophilia. The serum level of interferon-γ was decreased; however, serum levels of interleukin-4, interleukin-5, interleukin-6, interleukin-10, and tumor growth factor-β levels were elevated. She received a bortezomib, lenalidomide, and dexamethasone regimen. After one course of the treatment, the cutaneous manifestation rapidly improved and laboratory tests showed decrease of eosinophil cell count. Serum concentrations of immunoglobulin G decreased and plasma cells in bone marrow decreased. The serum level of interferon-γ was elevated and serum levels of interleukin-4, interleukin-5, interleukin-6, interleukin-10, and tumor growth factor-β decreased.

Conclusions

It is the first case of leukocytoclastic vasculitis and eosinophilia in multiple myeloma that was associated with a T helper type 1/T helper type 2 imbalance and T regulatory cells, and was successfully treated with bortezomib, lenalidomide, and dexamethasone. The present case reinforces the value of early evaluations for paraneoplastic symptoms in order to reach a diagnosis and allow for the prompt initiation of appropriate treatments and achieve successful therapeutic management.

Maintenance in myeloma patients achieving complete response after upfront therapy: a pooled analysis

PURPOSE

Maintenance demonstrated to improve survival in newly diagnosed multiple myeloma (NDMM) patients and the achievement of complete response (CR) is a strong predictor of survival. Nevertheless, the role of maintenance according to response after induction/consolidation has not been investigated so far. To evaluate the impact of maintenance according to response, we pooled together and retrospectively analyzed data from 955 NDMM patients enrolled in two trials (GIMEMA-MM-03-05 and RV-MM-PI-209).

METHODS

Primary endpoints were progression-free survival (PFS)1, PFS2 and overall survival (OS) of CR patients randomized to maintenance and no maintenance. Secondary endpoints were PFS1, PFS2 and OS in very good partial response/partial response (VGPR/PR) patients.

RESULTS

Overall, 213 patients obtained CR after induction/consolidation, 118 received maintenance and 95 no maintenance. In patients achieving CR, maintenance significantly improved PFS1 (HR 0.50, P < 0.001), PFS2 (HR 0.58, P 0.02) and OS (HR 0.51, P 0.02) compared with no maintenance; the advantage was maintained across all the analyzed subgroups according to age, International Staging System (ISS) stage, cytogenetic profile and treatment. Similar features were seen in VGPR/PR patients.

CONCLUSION

Maintenance prolonged survival in CR and in VGPR/PR patients. The benefit in CR patients suggests the importance of continuing treatment in patients with chemo-sensitive disease.

TRIAL REGISTRATION

The two source studies are registered at ClinicalTrials.gov: identification numbers NCT01063179 and NCT00551928.

Bavachin induces the apoptosis of multiple myeloma cell lines by inhibiting the activation of nuclear factor kappa B and signal transducer and activator of transcription 3

Bavachin is a phytoestrogen purified from natural herbal plants such as Psoralea corylifolia. In this study, we examined the effect of bavachin in multiple myeloma (MM) cell lines. We found that bavachin decreased the viability of MM cell lines, but was not cytotoxic towards normal cells. It inhibited the activation of nuclear factor kappa B (NF-κB) and signal transducer and activator of transcription 3 (STAT3). Furthermore, bavachin increased the expression of p53 and NOXA, and decreased the expression of X-linked inhibitor of apoptosis protein (XIAP), survivin, B cell lymphoma-extra large (Bcl-xL), and Bcl-2. Additionally, bavachin induced apoptosis by the activation of caspase-3 and caspase-9, implicating the involvement of the mitochondrial pathway. Our results suggest that bavachin induces apoptosis through the inhibition of NF-κB and STAT3 activation in MM cell lines. Most importantly, few NF-κB and STAT3 inhibitors with high efficiency, specificity, and safety are currently available for clinical cancer therapy. Hence, bavachin, which targets NF-κB and STAT3, is a potential anticancer agent for the treatment of MM.

Droplet Digital PCR for Minimal Residual Disease Detection in Mature Lymphoproliferative Disorders

Minimal residual disease (MRD) detection has a powerful prognostic relevance for response evaluation and prediction of relapse in hematological malignancies. Real-time quantitative PCR (qPCR) has become the settled and standardized method for MRD assessment in lymphoid disorders. However, qPCR is a relative quantification approach, since it requires a reference standard curve. Droplet digital^TM PCR (ddPCR^TM) allows a reliable absolute tumor burden quantification withdrawing the need for preparing, for each experiment, a tumor-specific standard curve. We have recently shown that ddPCR has a good concordance with qPCR and could be a feasible and reliable tool for MRD monitoring in mature lymphoproliferative disorders. In this chapter we describe the experimental workflow, from the detection of the clonal molecular marker to the MRD monitoring by ddPCR, in patients affected by multiple myeloma, mantle cell lymphoma and follicular lymphoma. However, standardization programs among different laboratories are needed in order to ensure the reliability and reproducibility of ddPCR-based MRD results.

Adipose, Bone, and Myeloma: Contributions from the Microenvironment

Researchers globally are working towards finding a cure for multiple myeloma (MM), a destructive blood cancer diagnosed yearly in ~750,000 people worldwide (Podar et al. in Expert Opin Emerg Drugs 14:99-127, 2009). Although MM targets multiple organ systems, it is the devastating skeletal destruction experienced by over 90 % of patients that often most severely impacts patient morbidity, pain, and quality of life. Preventing bone disease is therefore a priority in MM treatment, and understanding how and why myeloma cells target the bone marrow (BM) is fundamental to this process. This review focuses on a key area of MM research: the contributions of the bone microenvironment to disease origins, progression, and drug resistance. We describe some of the key cell types in the BM niche: osteoclasts, osteoblasts, osteocytes, adipocytes, and mesenchymal stem cells. We then focus on how these key cellular players are, or could be, regulating a range of disease-related processes spanning MM growth, drug resistance, and bone disease (including osteolysis, fracture, and hypercalcemia). We summarize the literature regarding MM-bone cell and MM-adipocyte relationships and subsequent phenotypic changes or adaptations in MM cells, with the aim of providing a deeper understanding of how myeloma cells grow in the skeleton to cause bone destruction. We identify avenues and therapies that intervene in these networks to stop tumor growth and/or induce bone regeneration. Overall, we aim to illustrate how novel therapeutic target molecules, proteins, and cellular mediators may offer new avenues to attack this disease while reviewing currently utilized therapies.

The effect of S1P receptor signaling pathway on the survival and drug resistance in multiple myeloma cells

Multiple myeloma (MM) remains incurable by conventional chemotherapy. Sphingosine-1-phosphate (S1P) receptor-mediated signaling has been recently demonstrated to have critical roles in cell survival and drug resistance in a number of hematological malignancies. To dissect the roles of S1P receptor pathway in MM, we systematically examined cell viability and protein expression associated with cell survival and drug resistance in MM cell lines upon treatment with either pathway activator (S1P) or inhibitor (FTY720). Our results reveal that FTY720 inhibits cell proliferation by downregulating expression of target genes, while S1P has an opposite effect. Knocking down of S1P receptor S1P5R results in a reduction of cell survival-related gene expression; however, it does not have impacts on expression of drug resistance genes. These results suggest that S1P signaling plays a role in cell proliferation and drug resistance in MM, and targeting this pathway will provide a new therapeutic direction for MM management.

Solitary Extramedullary Plasmacytoma of the Maxillary Sinus, Progressing to Smoldering Multiple Myeloma with Multifocal Skeletal Involvement, which Resolved Completely Following Chemotherapy Alone

Plasmacytoma is an uncommon malignant tumor originating either from plasma cells located in the bone marrow also known as the solitary bone plasmacytoma, or from plasma cells located outside the bone, for e.g. in mucosal surfaces, referred to as the extramedullary plasmacytoma also called the solitary extramedullary plasmacytoma. Both, solitary as well as extramedullary bone plasmacytomas may, particularly in later stages, be accompanied by other osteolytic bone lesions (multifocal bone involvement) and features such as anemia, hypercalcemia, or renal impairment attributable to and indicative of progression to multiple myeloma. These three distinct disorders together comprise the plasma cell neoplasms and essentially represent a continuum of related disease processes. Extramedullary and solitary bone plasmacytomas of the head and neck region are extremely uncommon, and amongst them plasmacytoma of the maxilla is extremely rare. Such a case is being reported here for its rarity. Also, it was associated with multifocal skeletal involvement, making a correct categorization difficult as well as imperative in order to institute the correct treatment. Radiotherapy is considered to be the treatment of choice of plasmacytoma, with adjuvant chemotherapy for multi focal involvement. Surgery is usually limited to biopsy and excision of any residual disease following radiotherapy. The case presented responded extremely well to chemotherapy alone, with a complete resolution of the maxillary tumor, obviating the need for radiotherapy.

Expression of the cereblon binding protein argonaute 2 plays an important role for multiple myeloma cell growth and survival

BACKGROUND

Immunomodulatory drugs (IMiDs), such as lenalidomide, are therapeutically active compounds that bind and modulate the E3 ubiquitin ligase substrate recruiter cereblon, thereby affect steady-state levels of cereblon and cereblon binding partners, such as ikaros and aiolos, and induce many cellular responses, including cytotoxicity to multiple myeloma (MM) cells. Nevertheless, it takes many days for MM cells to die after IMiD induced depletion of ikaros and aiolos and thus we searched for other cereblon binding partners that participate in IMiD cytotoxicity.

METHODS

Cereblon binding partners were identified from a MM cell line expressing histidine-tagged cereblon by pulling down cereblon and its binding partners and verified by co-immunoprecipitation. IMiD effects were determined by western blot analysis, cell viability assay, microRNA array and apoptosis analysis.

RESULTS

We identified argonaute 2 (AGO2) as a cereblon binding partner and found that the steady-state levels of AGO2 were regulated by cereblon. Upon treatment of IMiD-sensitive MM cells with lenalidomide, the steady-state levels of cereblon were significantly increased, whereas levels of AGO2 were significantly decreased. It has been reported that AGO2 plays a pivotal role in microRNA maturation and function. Interestingly, upon treatment of MM cells with lenalidomide, the steady-state levels of microRNAs were significantly altered. In addition, silencing of AGO2 in MM cells, regardless of sensitivity to IMiDs, significantly decreased the levels of AGO2 and microRNAs and massively induced cell death.

CONCLUSION

These results support the notion that the cereblon binding partner AGO2 plays an important role in regulating MM cell growth and survival and AGO2 could be considered as a novel drug target for overcoming IMiD resistance in MM cells.

Hypoxia inducible factor-1 alpha and multiple myeloma

Rapid tumor growth creates a state of hypoxia in the tumor microenvironment and results in release of hypoxia inducible factor-1 alpha (HiF-1α) in the local milieu. Hypoxia inducible factor activity is deregulated in many human cancers, especially those that are highly hypoxic. In multiple myeloma (MM) in initial stages of disease establishment, the hypoxic bone marrow microenvironment supports the initial survival and growth of the myeloma cells. Hypoxic tumour cells are usually resistant to radiotherapy and most conventional chemotherapeutic agents, rendering them highly aggressive and metastatic. Therefore, HIF is an attractive, although challenging, therapeutic target in MM directly or indirectly in recent years.

Immunomodulatory effect of DC/CIK combined with chemotherapy in multiple myeloma and the clinical efficacy

To investigate the clinical efficacy of adoptive immunotherapy using dendritic cells (DC) and cytokine-induced killer (CIK) cells combined with chemotherapy in multiple myeloma. The immunomodulatory effect of the therapy was discussed by detecting the levels of peripheral blood T cell subsets and CD4(+)CD25(+) regulatory cells (Treg). Fifty MM patients were randomly divided into two groups: 24 cases in the simple chemotherapy group and 26 cases in the combined therapy group (chemotherapy plus DC/CIK immunotherapy). The therapeutic efficacy and the proportions of peripheral blood T cell subsets and Treg cells were compared between the two groups. The cellular immunity indicators were also compared, including IL-2, IFN-γ, IL-4, IL-10, AgNORs ratio and TGF-β. After 3 weeks of treatment, the life quality and clinical efficacy of the combined therapy group were superior to those of the simple chemotherapy group (P<0.05). CD3(+)CD8(+) ratio, CD4(+)CD25(+) ratio, CD4(+)CD25(+)/CD4(+) ratio, CD4(+)CD25(+)FoxP3(+)/CD4(+)CD25(+) ratio, IL-4, IL-10 and TGF-β levels of the combined therapy group were obviously lower than those of the simple chemotherapy group (P<0.05). The CD3(+)CD4(+)/CD3(+)CD8(+) ratio, AgNOR ratio, IL-2 and IFN-γ level and positive rate of NKG2D in the combined therapy group were significantly higher than those of the simple chemotherapy group (P<0.05). These results indicated better immunomodulatory effect of the combined therapy. DC/CIK immunotherapy combined with chemotherapy has a good clinical efficacy and prospect for MM, reversing the Th1 to Th2 shift and increasing the anti-tumor capacity of the immune system.

miRNA-202 in bone marrow stromal cells affects the growth and adhesion of multiple myeloma cells by regulating B cell-activating factor

Bone marrow stromal cells (BMSCs) up-regulate B cell-activating factor (BAFF) in multiple myeloma. Increasing experimental evidence has shown that microRNAs play a causal role in hematology tumorigenesis. In this study, we characterized the role of miR-202 in regulating the expression of BAFF in BMSCs. It was found that expressions of BAFF mRNA and protein were increased in BMSCs treated with miR-202 inhibitor. The growth rate of miR-202 mimics transfection cells was significantly lower than that of non-transfected cells. The expression of Bcl-2 protein was down-regulated, and Bax protein was up-regulated after miR-202 mimics transfection. Over-expression of miR-202 in BMSCs rendered MM cells more sensitive to bortezomib. More significantly, the regulatory effect of miR-202 could inhibit the activation of NF-κB pathway in BMSCs. These results suggest that miR-202 functions as a modulator that can negatively regulate BAFF by inhibiting MM cell survival, growth, and adhesion in the bone marrow microenvironment.

Absolute lymphocyte count as predictor of overall survival for patients with multiple myeloma treated with single autologous stem cell transplant

Post-autologous stem cell transplant (ASCT) studies have demonstrated that absolute lymphocyte count (ALC) recovery is associated with prolonged survival in some hematological malignancies. To assess whether ALC recovery has prognostic significance in patients with multiple myeloma (MM) undergoing single ASCT, we conducted a retrospective analysis of ALC at different time-points in patients with MM. In total 769 consecutive patients who underwent single ASCT from January 2000 to December 2007 were evaluated. An ALC of ≥ 1400 cells/μL at day 0, day 15 and day 90 significantly correlated with a better overall survival (OS) (median OS of 111, 90.7 and 84 months vs. 74, 70.5 and 65 months, respectively, p < 0.001 for all time-points). Multivariate analysis showed that ALC is an independent prognostic factor for OS after ASCT. In conclusion, ALC is a surrogate marker of the host immune system that correlates with better survival in patients with MM undergoing single ASCT. Immunomodulatory drugs, vaccination strategies and cellular therapies in MM should be investigated.

Myelomatous pleural effusion as an initial sign of multiple myeloma-a case report and review of literature

OBJECTIVE

Discuss and improve the understanding of the clinical characters and diagnostic methods of myelomatous pleurisy, particularly of the patients with pleural effusion as an initial manifestation.

BACKGROUND

A 53-year-old male, who had been misdiagnosed as tuberculous pleurisy in a local hospital, was diagnosed as multiple myeloma (MM) with pleural infiltration. We reviewed the literature on clinical manifestations, serum and pleural effusion characters, treatment and diagnostic options of this exceptionally rare presentation of MM.

METHODS

We conducted a search of the published medical literature since 2000 in MEDLINE and PubMed using search criteria [("pleural effusion" and "MM") or "myelomatous pleural effusions"]. The search led to 64 case reports, and 16 cases with pleural effusion as an initial manifestation were included in this review. We have also searched for recent advances in diagnosis.

RESULTS AND CONCLUSIONS

Myelomatous pleurisy is a rare complication of MM. Its clinical and laboratory findings are non-specific. Definitive diagnosis relies on the histopathology of pleural biopsy or pleural effusion. Thoracoscopic pleural biopsy is reliable, safe and effective. Chemotherapy is the mainstay of treatment for myelomatous pleural effusion. However, the response rate is low with an overall median survival time of 4 months.

Oligoclonal and monoclonal bands after single autologous stem cell transplant in patients with multiple myeloma: impact on overall survival and progression-free survival

Abstract Recently, the occurrence of oligoclonal and monoclonal bands (OB/MB) unrelated to the original clone has been reported in patients with multiple myeloma who undergo autologous stem cell transplant (ASCT) and/or receive treatment with novel agents. The aim of our study was to assess the impact of OB/MB occurrence on overall (OS) and progression-free survival (PFS) for patients with MM undergoing single ASCT at our institution. All consecutive patients with documented MM undergoing single ASCT from January 2000 to December 2012 were evaluated. Ninety-nine patients (11.8%) developed OB/MB at day 100 post-ASCT (32.3%, OB and 67.7%, MB). Multivariate analysis identified the development of OBs/MBs as an independent favorable prognostic factor for OS and PFS (p = 0.008 and 0.012, respectively). In conclusion, the occurrence of OB/MB is an important prognostic factor in patients with MM who undergo ASCT. Its impact on clinical outcomes should be prospectively validated and its biological significance further elucidated.

Characterization of multiple myeloma clonal cell expansion and stromal Wnt/β-catenin signaling in hyaluronic acid-based 3D hydrogel

BACKGROUND

Emerging interest on three-dimensional (3D) cell culture models to replace two-dimensional cultures of cancer cells and their xenografts in immunocompromised animal hosts prompted us to investigate the use of new biodegradable gels to recapitulate the physiological conditions of the microenvironment of multiple myeloma (MM) cells.

MATERIALS AND METHODS

In the present study, for the first time, we used a new 3D model of hyaluronic acid (HA)-based hydrogels with difference in their matrix composition and stiffness.

RESULTS

We demonstrated that hyaluronic acid (HA)-based hydrogels perfectly accommodate MM cells; confirmed by cell survival, migration, colony forming units and expression of cell adhesion proteins of the Wnt signaling pathways over a period of time.

CONCLUSION

This study provides the first 3D microenvironment data that HA-based hydrogels could provide with a suitable 3D substratum for MM cells to comprehensively analyze phenotypic changes and the influence of bone marrow stromal stem cells on Wnt/β catenin signaling in response to targeted drug treatments.