The role of CXCR4 in multiple myeloma: Cells' journey from bone marrow to beyond

Bioinformatics analysis of intrinsic drivers of immune dysregulation in multiple myeloma to elucidate immune phenotypes and discover prognostic gene signatures

Multiple myeloma (MM) progression is driven by immune dysregulation within the tumor microenvironment (TME). However, myeloma-intrinsic mechanisms underlying immune dysfunction remain poorly defined, and current immunotherapies show limited efficacy. Using RNA-seq data from 859 MM patients (MMRF-CoMMpass), we integrated xCELL, CIBERSORT, and ESTIMATE algorithms to deconvolute immune-stromal dynamics. Consensus clustering identified immune subtypes, followed by differential gene analysis and LASSO-Cox regression to construct a prognostic model validated in an independent cohort (GSE19784, N = 328). Immune Subtype Classification: Two subgroups emerged: Multiple myeloma-associated immune-related cluster 1 (N = 482): Immune-dysfunctional TME with Th2 cell enrichment, preadipocyte accumulation, and CXCL family suppression, linked to poor survival (P < 0.001). Multiple myeloma-associated immune-related cluster 2 (N = 377): Immune-active TME with cytotoxic CD8 + T/NK cell infiltration and favorable outcomes. Prognostic Gene Signature: Ten immune-related genes (UBE2T, E2F2, EXO1, SH2D2A, DRP2, WNT9A, SHROOM3, TMC8, CDCA7, and GPR132) predicted survival (The One-year AUC = 0.682 and The Over 5-years AUC = 0.714). We define a myeloma-intrinsic immune classification system and a 10-gene prognostic index, offering a framework for risk-stratified immunotherapy. Integration with flow cytometry could optimize precision treatment in MM.

Diagnostic Innovations: Advances in imaging techniques for diagnosis and follow-up of multiple myeloma

Introduction

The International Myeloma Working Group (IMWG) defines myeloma related bone disease (MBD) as a diagnostic criterion for symptomatic multiple myeloma (MM) as the presence of osteolytic lesions ≥ 5 mm or more than one focal lesion (FL) ≥ 5 mm by magnetic resonance imaging (MRI). Whole-body low-dose CT (WBLDCT) is recommended as the first-choice imaging technique for the diagnosis of MBD with 18F-fluorodeoxyglucose-positron emission tomography/CT (18F-FDG-PET/CT) being considered a possible alternative at staging, whereas use of MRI studies is recommended in cases without myeloma-defining events (MDEs) in order to exclude the presence of FLs. Furthermore, use of 18F-FDG-PET/CT is recommended in response assessment, to be integrated with hematologic response and bone marrow minimal residual disease (MRD).

Areas covered

In this paper, we review novel functional imaging techniques in MM, particularly focusing on their advantages, limits, applications and comparisons with 18F-FDG-PET/CT or other standardized imaging techniques.

Conclusions

Combining both morphological and functional imaging, 18F-FDG-PET/CT is currently considered a standard imaging technique in MM for staging (despite false positive or negative results) and response assessment. The introduction of novel functional imaging techniques, as whole-body diffusion-weighted magnetic resonance imaging (WB-DWI-MRI), or novel PET tracers might be useful in overcoming these limits. Future studies will give more information on the complementarity of these imaging techniques or whether one of them might become a new gold standard in MM.

Mesenchymal stromal cells in bone marrow niche of patients with multiple myeloma: a double-edged sword

Multiple myeloma (MM) is a hematological malignancy defined by the abnormal proliferation and accumulation of plasma cells (PC) within the bone marrow (BM). While multiple myeloma impacts the bone, it is not classified as a primary bone cancer. The bone marrow microenvironment significantly influences the progression of myeloma and its treatment response. Mesenchymal stromal cells (MSCs) in this environment engage with myeloma cells and other bone marrow components via direct contact and the secretion of soluble factors. This review examines the established roles of MSCs in multiple facets of MM pathology, encompassing their pro-inflammatory functions, contributions to tumor epigenetics, effects on immune checkpoint inhibitors (ICIs), influence on reprogramming, chemotherapy resistance, and senescence. This review investigates the role of MSCs in the development and progression of MM.

Nutrients Lowering Obesity-Linked Chemokines Blamable for Metastasis

Food intake is an essential contributor to both health and disease. Nutrients contribute to a beneficial metabolic equilibrium at the cellular level, preventing or delaying disease onset. Dietary intake contributes to obesity, and obesity supports further cancer and metastasis. Metastasis, a multifactorial and multistep process, is supported by the systemic inflammation of obesity. Spreading of the cancer cells requires the presence of a plethora of recruiter and regulator molecules. Molecules such as chemokines are provided at high levels by obesity-associated fat depots. Chemokine up-regulation in adipose tissue of obese individuals has been associated with different types of cancers such as breast, prostate, colon, liver, and stomach. Chemokines support all metastasis steps from invasion/migration to intravasation, circulation, extravasation, and ending with colonization. The obesity pool of chemokines supporting these processes includes CCL2, CCL3, CCL4, CCL5, CCL7, CCL8, CCL11, CCL18, CCL19, CCL20, CXCL1, CXCL5, CXCL 8, CXCL10, and CXCL12. Keeping obesity under control can be beneficial in reducing the levels of pro-inflammatory chemokines and the risk of poor cancer outcome. Nutrients can help, support, and boost cancer treatment effects or jeopardize the treatment. Constituents with anti-inflammatory and anti-obesity properties such as polyphenols, organosulfur components, fatty acids, curcumin, and vitamin E have a proven beneficial effect in lowering obesity and its contribution to metastasis.

Comprehensive analysis of mitochondrial-related gene signature for prognosis, tumor immune microenvironment evaluation, and candidate drug development in colon cancer

Colon adenocarcinoma (COAD), a common digestive system malignancy, involves crucial alterations in mitochondria-related genes influencing tumor growth, metastasis, and immune evasion. Despite limited studies on prognostic models for these genes in COAD, we established a mitochondrial-related risk prognostic model, including nine genes based on available TCGA and MitoCarta 3.0 databases, and validated its predictive power. We investigated the tumor microenvironment (TME), immune cell infiltration, complex cell communication, tumor mutation burden, and drug sensitivity of COAD patients using R language, CellChat, and additional bioinformatic tools from single-cell and bulk-tissue sequencing data. The risk model revealed significant differences in immune cell infiltration between high-risk and low-risk groups, with the strongest correlation found between tissue stem cells and macrophages in COAD. The risk score exhibited a robust correlation with TME signature genes and immune checkpoint molecules. Integrating the risk score with the immune score, microsatellite status, or TMB through TIDE analysis enhanced the accuracy of predicting immunotherapy benefits. Predicted drug efficacy offered options for both high- and low-risk group patients. Our study established a novel mitochondrial-related nine-gene prognostic signature, providing insights for prognostic assessment and clinical decision-making in COAD patients.

Single-cell landscape of dynamic changes in CD8+ T cells, CD4+ T cells and exhausted T cells in hepatocellular carcinoma

Hepatocellular carcinoma has a high incidence and poor prognosis. In this study, we investigated the value of T-cell-related genes in prognosis by single-cell sequencing data in hepatocellular carcinoma. Twelve cases of hepatocellular carcinoma single-cell sequencing were included in the study. The high dimensional weighted gene co-expression network analysis (hdWGCNA) was used to identify gene modules associated with CD4+ T cells, CD8+ T cells and exhausted T cells. Altered signaling pathway activity in exhausted T cells was uncovered by the AUCell algorithm. xCELL, TIMER, QUANTISEQ, CIBERSORT and CIBERSORT-abs were performed to explore immune cell infiltration. Immune checkpoint inhibitor genes and TIDE methods were used to predict immunotherapy response. Finally, immunohistochemistry and real-time PCR were used to verify gene expression. The hdWGCNA algorithm identified 40 genes strongly associated with CD4+ T cells, CD8+ T cells and exhausted T cells. Seven genes were finally selected for transcriptome data modeling. The results of the three independent datasets suggested that the model had strong prognostic value. Model genes were critical factors influencing CD4+ T cell and CD8+ T cell infiltration in patients. The efficacy of PD-1 immunotherapy was higher in patients belonging to the low-risk group. Alterations in signaling pathways' activity within exhausted T cells were crucial factors contributing to the decline in immune function. Differential expression of seven genes in CD8+ T cells, CD4+ T cells and exhausted T cells were key targets for improving immunotherapy response in HCC.

Extramedullary plasmacytoma with the uvula as first affected site: A case report

BACKGROUND

Extramedullary plasmacytoma (EMP) represents one of the rarer forms of plasma cell malignancies, capable of impacting a variety of tissues and organs throughout the body. The majority of EMP cases are predominantly found in the head and neck region, especially within the laryngopharynx, as well as in the gastrointestinal tract. While there have been documented instances of oropharyngeal involvement in EMP cases in the academic literature, it is important to note that EMP specifically affecting the uvula is exceedingly uncommon. Furthermore, it is noteworthy that over 60% of epithelial carcinomas in the upper respiratory tract and oropharynx tend to metastasize to the cervical lymph nodes, indicating a propensity for regional spread in these types of cancers. In this context, we present a rare case of extramedullary plasmacytoma where the uvula served as the initially affected site. This case emphasizes the need for heightened awareness among clinicians regarding such unusual comorbidities, as early recognition and diagnosis can significantly influence patient management and treatment outcomes. In addition, a review of the relevant literature is included to further educate and inform healthcare professionals about this rare presentation, ultimately aiming to enhance clinical understanding and improve patient care in similar situations.

CASE SUMMARY

A 51-year-old man was admitted to our hospital because of a slowly enlarging neck mass. A physical examination revealed a palpable left lymph node, and magnetic resonance imaging (MRI) of the oropharynx and the neck showed a soft tissue mass in the oropharynx and enlargement of multiple lymph nodes in the neck. The soft tissue mass was diagnosed as plasmacytoma by immunohistochemical analysis. Monoclonal immunoglobulins and bone marrow biopsy showed normal results. Therefore, we diagnosed that as EMP of the uvula. After four cycles of adjuvant chemotherapy dominated by bortezomib, MRI reexamination showed a significant reduction of the mass in the oropharynx and the cervical lymph nodes. Afterwards, the λ light chain returned to normal levels. There was no evidence of evolution to multiple myeloma.

CONCLUSION

We have reported a rare case of extramedullary plasmacytoma with the uvula as the first affected site and the relevant literature is reviewed to improve clinicians' awareness of such rare comorbidities.

CXCR4-Targeted PET Imaging in Hematologic Malignancies: A Systematic Review and Meta-analysis

PURPOSE

The aims of this study were to perform a comprehensive review and meta-analyses and to report pooled diagnostic results on CXCR4-targeted PET, particularly considering detection, visualization, and prognostication.

PATIENTS AND METHODS

This study followed PRISMA-DTA. A systematic search was conducted on major medical literature databases up to March 1, 2024. The search strategy was designed to include CXCR4 PET studies in hematologic malignancies. A random-effects model combined sensitivity values derived from 2-by-2 contingency tables. Pooled means for SUV max were computed. Analyses were performed by R software.

RESULTS

The initial search resulted in a total of 1428 studies. Ultimately, 18 were eligible for systematic review and meta-analytic calculations. Twelve studies (320 patients) included B-cell lymphoma. The pooled detection rate of CXCR4 PET was 99.4% (95% confidence interval [CI]: 88.3%-100%). Marginal zone lymphoma was investigated in 5 studies (209 patients), with a pooled sensitivity of 97.6% (95% CI: 79.7%-99.8%). In studies on central nervous system lymphoma, CXCR4 PET demonstrated 100% accuracy at both patient and lesion levels. Also, it demonstrated a significantly higher tumor-to-background ratio than 18 F-FDG PET. For multiple myeloma, 5 studies (116 patients) showed a patient-level pooled sensitivity of 77.8% (95% CI: 64.4%-87.2%), whereas 18 F-FDG PET had 65.0% (95% CI: 55.2%-73.7%). The pooled SUV max for CXCR4 PET was 13.6 (95% CI: 9.3-17.8) versus 9.0 (95% CI: 6.3-11.7) for 18 F-FDG PET. Additionally, CXCR4 PET-derived parameters were significant predictors of survival in multiple myeloma.

CONCLUSIONS

CXCR4 PET can be a helpful imaging tool for evaluating hematologic malignancies, particularly in B-cell lymphoma and multiple myeloma patients. In specific clinical scenarios, it appears to be superior compared with the current standard-of-care imaging.

A comprehensive review of oncogenic Notch signaling in multiple myeloma

Multiple myeloma remains an incurable plasma cell cancer with radical case-by-case heterogeneity. Because of this, personalized and disease-specific biology of multiple myeloma must be understood for the discovery of effective molecular targets. The highly evolutionarily conserved Notch signaling pathway has been extensively described as a multifaceted driver of the multiple myeloma disease process-contributing to both intrinsic effects of malignant cells and to widespread remodeling of the tumor microenvironment that further facilitates disease progression. Namely, Notch signaling amongst malignant cells promotes increased proliferation, tumor-initiating capacity, drug resistance, and invasiveness. Moreover, Notch signaling between malignant cells and cells of the tumor microenvironment leads to increased osteodegenerative disease and angiogenesis. This comprehensive review will discuss both the intrinsic implications of pathological Notch signaling in multiple myeloma and the extrinsic implications of Notch signaling in the multiple myeloma tumor microenvironment. Additionally, the genetic origins of Notch signaling dysregulation in multiple myeloma and current attempts at targeting Notch therapeutically will be reviewed. While the subject has been reviewed previously, recent developments in the intervening years demand a revised synthesis of the literature. The aim of this work is to introduce and thoroughly synthesize the current state of knowledge in this vein of research and to highlight future directions for both new and in-the-field scientists.

Investigating the effect of immunomagnetic separation on the immunophenotype and viability of plasma cells in plasma cell disorders

Plasma cell enrichment plays a pivotal role in the accurate prognosis and molecular characterization of multiple myeloma. The separation is commonly carried out by positive cell selection using CD138 monoclonal antibody conjugated to magnetic beads. Optimally, during the separation procedure, the cells should neither be damaged, nor should their phenotype be significantly altered, as these changes would falsify the results if the isolated cells were subsequently used. For this reason, we investigated the expression patterns of different surface markers by flow cytometry before and after magnetic isolation using bone marrow or peripheral blood samples from 12 patients with plasma cell disorders. The selected markers are not only used as backbone markers in routine diagnostics (CD19, CD38, CD45, CD117, and CD138), but they also play an important role in cell adhesion and connection with microenvironment (CD44, CD49d, CD56, and CD81) or possibly drug resistance (CD69, CD86, and CD184), making them promising targets for myeloma research. Moreover, we examined the effects of separation on cell viability in 8 cases. The intensities of 8 out of the 12 investigated markers were slightly influenced, while CD138, CD38, CD56, and CD184 were changed significantly, however the immunophenotype of the cells was not changed. Positive markers remained positive and negative ones remained negative after the separation procedure. In addition, the number of apoptotic plasma cells was significantly reduced during separation, facilitating further examination of the cells. Our results showed that magnetic isolation can be considered as a reliable option but the immunophenotype of plasma cells should be validated after the separation if the intensities of the markers are important for further experiments.

Alterations of receptors and insulin-like growth factor binding proteins in senescent cells

The knowledge about cellular senescence expands dynamically, providing more and more conclusive evidence of its triggers, mechanisms, and consequences. Senescence-associated secretory phenotype (SASP), one of the most important functional traits of senescent cells, is responsible for a large extent of their context-dependent activity. Both SASP's components and signaling pathways are well-defined. A literature review shows, however, that a relatively underinvestigated aspect of senescent cell autocrine and paracrine activity is the change in the production of proteins responsible for the reception and transmission of SASP signals, i.e., receptors and binding proteins. For this reason, we present in this article the current state of knowledge regarding senescence-associated changes in cellular receptors and insulin-like growth factor binding proteins. We also discuss the role of these alterations in senescence induction and maintenance, pro-cancerogenic effects of senescent cells, and aging-related structural and functional malfunctions.

IgG-k/IgG-λ Para-Osseous Plasmacytoma Relapsed as Soft-Tissue Plasmacytoma with IgA-k Immunophenotype: A Case Report and Review of the Literature on Related Biochemical Aspects

Neoplastic plasma cells (PCs) proliferation at anatomic sites dislocated from the bone marrow (BM) or their contiguous growth from osseous lesions that disrupt the cortical bone is termed extramedullary multiple myeloma (EMD). EMD still remains challenging from a therapeutic and biological perspective. Pathogenesis has not been completely clarified, and it is generally associated with high-risk cytogenetics (HRCAs). In order to emphasize the clinical and biochemical complexity of this disease, we have decided to describe the case of a patient affected by relapsed-refractory (RR) EMD, which presented as para-osseous plasmacytoma with a bi-phenotypical immunoglobulin (Ig) component and lately relapsed as soft-tissue plasmacytoma with a total immunophenotype switch. We have also hypothesized a correlation between Ig patterns and prognosis and suggested the possible inclusion of these biochemical features in the general risk assessment.

A NOTCH3-CXCL12-driven myeloma-tumor niche signaling axis promotes chemoresistance in multiple myeloma

Multiple myeloma (MM) remains incurable due to disease relapse and drug resistance. Notch signals from the tumor microenvironment (TME) confer chemoresistance, but the cellular and molecular mechanisms are not entirely understood. Using clinical and transcriptomic datasets, we found that NOTCH3 is upregulated in CD138+ cells from newly diagnosed MM (NDMM) patients compared to healthy individuals and increased in progression/relapsed MM (PRMM) patients. Further, NDMM patients with high NOTCH3 expression exhibited worse responses to bortezomib (BOR)-based therapies. Cells of the TME, including osteocytes, upregulated NOTCH3 in MM cells and protected them from apoptosis induced by BOR. NOTCH3 activation (NOTCH3OE) in MM cells decreased BOR anti-MM efficacy and its ability to improve survival in in vivo myeloma models. Molecular analyses revealed that NDMM and PRMM patients with high NOTCH3 exhibit CXCL12 upregulation. TME cells upregulated CXCL12 and activated the CXCR4 pathway in MM cells in a NOTCH3-dependent manner. Moreover, genetic or pharmacologic inhibition of CXCL12 in NOTCH3OE MM cells restored sensitivity to BOR regimes in vitro and in human bones bearing NOTCH3OE MM tumors cultured ex vivo. Our clinical and preclinical data unravel a novel NOTCH3-CXCL12 pro-survival signaling axis in the TME and suggest that osteocytes transmit chemoresistance signals to MM cells.

Advancements in microenvironment-based therapies: transforming the landscape of multiple myeloma treatment

Multiple myeloma (MM) is the most prevalent malignant monoclonal disease of plasma cells. There is mounting evidence that interactions with the bone marrow (BM) niche are essential for the differentiation, proliferation, survival, migration, and treatment resistance of myeloma cells. For this reason, gaining a deeper comprehension of how BM microenvironment compartments interact with myeloma cells may inspire new therapeutic ideas that enhance patient outcomes. This review will concentrate on the most recent findings regarding the mechanisms of interaction between microenvironment and MM and highlight research on treatment targeting the BM niche.

Comprehensive analysis of serum cytokines in patients with multiple myeloma before and after lenalidomide and dexamethasone

Multiple myeloma (MM) is an incurable B-cell malignancy often accompanied by profound immunodeficiency. Lenalidomide (Len) is an immunomodulatory drug that exerts promising therapeutic effects on MM through the immune system. However, predictive markers related to the effects of Len treatment are not fully understood. This study aimed to identify candidate biomarkers for predicting the clinical efficacy of Len and dexamethasone (Ld) therapy through a comprehensive analysis of serum cytokines. The levels of 48 cytokines in the serum of patients with MM just before Ld therapy (n = 77), at the time of best response (n = 56), and at disease progression (n = 49) were measured and evaluated. Patients with high IL-18 and M-CSF levels showed significantly shorter progression-free survival and overall survival (OS). In contrast, patients with high PDGF-BB levels had longer survival. Moreover, low levels of G-CSF, IL-7, IL-8, and SDF-1α were associated with shorter OS after Ld therapy. During Ld therapy, pro-inflammatory cytokines such as IL-2Rα, IL-18, and TNF-α were decreased, while IFN-γ was increased. IL-4 and IL-6 levels increased during disease progression. In conclusion, this study provides a better understanding of the association between cytokines and the efficacy of Ld therapy as well as the unique changes in cytokines related to inflammatory and immune responses during Ld therapy.

Pathways to therapy resistance: The sheltering effect of the bone marrow microenvironment to multiple myeloma cells

Multiple Myeloma (MM) is a malignant expansion of plasma cells in the bone marrow (BM), resulting in a disease characterized by symptoms of end organ damage from light chain secretion, crowding of the BM, and bone lesions. Although the past two decades have been characterized by numerous novel therapies emerging, the disease remains incurable due to intrinsic or acquired drug resistance. A major player in MM's drug resistance arises from its intimate relationship with the BM microenvironment (BMME). Through stress-inducing conditions, soluble messengers, and physical adhesion to BM elements, the BMME activates numerous pathways in the myeloma cell. This not only propagates myeloma progression through survival and growth signals, but also specific mechanisms to circumvent therapeutic actions. In this review, we provide an overview of the BMME, the role of individual components in MM survival, and various therapy-specific resistance mechanisms reported in the literature.

Extracellular Vesicles in the Repair of Bone and Cartilage Injury: From Macro‐Delivery to Micro‐Modification

Extracellular vesicles (EVs) are intermediaries in intercellular signal transmission and material exchange and have attracted significant attention from researchers in bone and cartilage repair. These nanoscale vesicles hold immense potential in facilitating bone and cartilage repair and regeneration by regulating the microenvironment at an injury site. However, their in vivo utilization is limited by their self‐clearance and random distribution. Therefore, various delivery platforms have been developed to improve EV targeting and retention rates in target organs while achieving a controlled release of EVs. Additionally, engineering modification of EVs has been proposed to effectively enhance EVs' intrinsic targeting and drug‐loading abilities and further improve their therapeutic effects on bone and cartilage injuries. This review aims to introduce the biogenesis of EVs and their regulatory mechanisms in the microenvironment of bone and cartilage injuries and comprehensively discuss the application of EV‐delivery platforms of different materials and various EV engineering modification methods in treating bone and cartilage injuries. The review's findings can help advance EV research and develop new strategies for improving the therapy of bone and cartilage injuries.

In vitro effects and mathematical modelling of CTCE-9908 (a chemokine receptor 4 antagonist) on melanoma cell survival

CTCE-9908, a CXC chemokine receptor 4 (CXCR4) antagonist, prevents CXCR4 phosphorylation and inhibits the interaction with chemokine ligand 12 (CXCL12) and downstream signalling pathways associated with metastasis. This study evaluated the in vitro effects of CTCE-9908 on B16 F10 melanoma cells with the use of mathematical modelling. Crystal violet staining was used to construct a mathematical model of CTCE-9908 B16 F10 (melanoma) and RAW 264.7 (non-cancerous macrophage) cell lines on cell viability to predict the half-maximal inhibitory concentration (IC50). Morphological changes were assessed using transmission electron microscopy. Flow cytometry was used to assess changes in cell cycle distribution, apoptosis via caspase-3, cell survival via extracellular signal-regulated kinase1/2 activation, CXCR4 activation and CXCL12 expression. Mathematical modelling predicted IC50 values from 0 to 100 h. At IC50, similar cytotoxicity between the two cell lines and ultrastructural morphological changes indicative of cell death were observed. At a concentration 10 times lower than IC50, CTCE-9908 induced inhibition of cell survival (p = 0.0133) in B16 F10 cells but did not affect caspase-3 or cell cycle distribution in either cell line. This study predicts CTCE-9908 IC50 values at various time points using mathematical modelling, revealing cytotoxicity in melanoma and non-cancerous cells. CTCE-9908 significantly inhibited melanoma cell survival at a concentration 10 times lower than the IC50 in B16 F10 cells but not RAW 264.7 cells. However, CTCE-9908 did not affect CXCR4 phosphorylation, apoptosis,\ or cell cycle distribution in either cell line.

Liquid Overlay and Collagen-Based Three-Dimensional Models for In Vitro Investigation of Multiple Myeloma

Multiple myeloma (MM) clones reside in the bone marrow (BM), which plays a role in its survival and development. The interactions between MM and their neighboring mesenchymal stromal cells (MSCs) have been shown to promote MM growth and drug resistance. However, those interactions are often missing or misrepresented in traditional two-dimensional (2D) culture models. Application of novel three-dimensional (3D) models might recapitulate the BM niche more precisely, which will offer new insights into MM progression and survival. Here, we aimed to establish two 3D models, based on MSC spheroids and collagen droplets incorporating both MM cells and MSCs with the goal of replicating the native myeloma context of the BM niche. This approach revealed that although MSCs can spontaneously assemble spheroids with altered metabolic traits, MSC spheroid culture does not support the integration of MM cells. On the contrary, collagen-droplet culture supported the growth of both cell types. In collagen, MSC proliferation was reduced, with the correlating decrease in ATP production and Ki-67 expression, which might resemble in vivo conditions, rather than 2D abundance of nutrients and space. MSCs and MMs were distributed homogenously throughout the collagen droplet, with an apparent CXCL12 expression in MSCs. In addition, the response of MM cells to bortezomib was substantially reduced in collagen, indicating the importance of 3D culture in the investigation of myeloma cell behavior, as drug resistance is one of the most pertinent issues in cancer therapy.

Targeted therapy for multiple myeloma: an overview on CD138-based strategies

Multiple myeloma (MM) is an incurable hematological disease characterized by the uncontrolled growth of plasma cells primarily in the bone marrow. Although its treatment consists of the administration of combined therapy regimens mainly based on immunomodulators and proteosome inhibitors, MM remains incurable, and most patients suffer from relapsed/refractory disease with poor prognosis and survival. The robust results achieved by immunotherapy targeting MM-associated antigens CD38 and CD319 (also known as SLAMF7) have drawn attention to the development of new immune-based strategies and different innovative compounds in the treatment of MM, including new monoclonal antibodies, antibody-drug conjugates, recombinant proteins, synthetic peptides, and adaptive cellular therapies. In this context, Syndecan1 (CD138 or SDC1), a transmembrane heparan sulfate proteoglycan that is upregulated in malignant plasma cells, has gained increasing attention in the panorama of MM target antigens, since its key role in MM tumorigenesis, progression and aggressiveness has been largely reported. Here, our aim is to provide an overview of the most important aspects of MM disease and to investigate the molecular functions of CD138 in physiologic and malignant cell states. In addition, we will shed light on the CD138-based therapeutic approaches currently being tested in preclinical and/or clinical phases in MM and discuss their properties, mechanisms of action and clinical applications.

Development of a cell adhesion-based prognostic model for multiple myeloma: Insights into chemotherapy response and potential reversal of adhesion effects

Multiple myeloma (MM) is a hematologic malignancy notorious for its high relapse rate and development of drug resistance, in which cell adhesion-mediated drug resistance plays a critical role. This study integrated four RNA sequencing datasets (CoMMpass, GSE136337, GSE9782, and GSE2658) and focused on analyzing 1706 adhesion-related genes. Rigorous univariate Cox regression analysis identified 18 key prognosis-related genes, including KIF14, TROAP, FLNA, MSN, LGALS1, PECAM1, and ALCAM, which demonstrated the strongest associations with poor overall survival (OS) in MM patients. To comprehensively evaluate the impact of cell adhesion on MM prognosis, an adhesion-related risk score (ARRS) model was constructed using Lasso Cox regression analysis. The ARRS model emerged as an independent prognostic factor for predicting OS. Furthermore, our findings revealed that a heightened cell adhesion effect correlated with tumor resistance to DNA-damaging drugs, protein kinase inhibitors, and drugs targeting the PI3K/Akt/mTOR signaling pathway. Nevertheless, we identified promising drug candidates, such as tirofiban, pirenzepine, erlotinib, and bosutinib, which exhibit potential in reversing this resistance. In vitro, experiments employing NCIH929, RPMI8226, and AMO1 cell lines confirmed that MM cell lines with high ARRS exhibited poor sensitivity to the aforementioned candidate drugs. By employing siRNA-mediated knockdown of the key ARRS model gene KIF14, we observed suppressed proliferation of NCIH929 cells, along with decreased adhesion to BMSCs and fibronectin. This study presents compelling evidence establishing cell adhesion as a significant prognostic factor in MM. Additionally, potential molecular mechanisms underlying adhesion-related resistance are proposed, along with viable strategies to overcome such resistance. These findings provide a solid scientific foundation for facilitating clinically stratified treatment of MM.

Preclinical and clinical evaluation of the Janus Kinase inhibitor ruxolitinib in multiple myeloma

Multiple myeloma (MM) is the most common primary malignancy of the bone marrow. No established curative treatment is currently available for patients diagnosed with MM. In recent years, new and more effective drugs have become available for the treatment of this B-cell malignancy. These new drugs have often been evaluated together and in combination with older agents. However, even these novel combinations eventually become ineffective; and, thus, novel therapeutic approaches are necessary to help overcome resistance to these treatments. Recently, the Janus Kinase (JAK) family of tyrosine kinases, specifically JAK1 and JAK2, has been shown to have a role in the pathogenesis of MM. Preclinical studies have demonstrated a role for JAK signaling in direct and indirect growth of MM and downregulation of anti-tumor immune responses in these patients. Also, inhibition of JAK proteins enhances the anti-MM effects of other drugs used to treat MM. These findings have been confirmed in clinical studies which have further demonstrated the safety and efficacy of JAK inhibition as a means to overcome resistance to currently available anti-MM therapies. Additional studies will provide further support for this promising new therapeutic approach for treating patients with MM.

In-situ wound healing by SDF-1-mimic peptide-loaded click crosslinked hyaluronic acid scaffold

Endogenous stem cell-based in-situ tissue regeneration has recently gained considerable attention. In this study, we investigated the potential of a chemokine, SDF-1-mimic peptide (SMP), to promote endogenous stem cell-based in-situ wound healing. Our approach involved the development of a click crosslinked hyaluronic acid scaffold loaded with SMP (Cx-HA + SMP) to release SMP in a wound site. The Cx-HA scaffold maintained its structural integrity throughout the wound healing process and also captured endogenous stem cells. Gradual SMP release from the Cx-HA + SMP scaffold established a concentration gradient at the wound site. In animal wound experiments, Cx-HA + SMP exhibited faster wound contraction compared to Cx-HA + SDF-1. Additionally, Cx-HA + SMP resulted in approximately 1.2-1.6 times higher collagen formation compared to Cx-HA + SDF-1. SMP released from the Cx-HA + SMP scaffold promoted endogenous stem cell migration to the wound site 1.5 times more effectively than Cx-HA + SDF-1. Moreover, compared to Cx-HA + SDF-1, Cx-HA + SMP exhibited higher expression of CXCR4 and CD31, as well as the positive markers CD29 and CD44 for endogenous stem cells. The endogenous stem cells that migrated through Cx-HA + SMP regenerated into wound skin with minimal scar granule formation, similar to the normal tissue. In conclusion, SMP peptide offers greater convenience, while efficiently attracting migrating endogenous stem cells compared to the SDF protein. Our findings suggest that Cx-HA + SMP scaffolds hold promise as a strategy to enhance endogenous stem cell-based in-situ wound healing.

Multiple Myeloma in 2023 Ways: From Trials to Real Life

Multiple myeloma is a chronic hematologic malignancy that obstinately tends to relapse. Basic research has made giant strides in better characterizing the molecular mechanisms of the disease. The results have led to the manufacturing of new, revolutionary drugs which have been widely tested in clinical trials. These drugs have been approved and are now part of the therapeutic armamentarium. As a consequence, it is essential to combine what we know from clinical trials with real-world data in order to improve therapeutic strategies. Starting with this premise, our review aims to describe the currently employed regimens in multiple myeloma and compare clinical trials with real-life experiences. We also intend to put a spotlight on promising therapies such as T-cell engagers and chimeric antigen receptor T-cells (CAR-T) which are proving to be effective in changing the course of advanced-stage disease.

Potential role of human umbilical cord stem cells-derived exosomes as novel molecular inhibitors of hepatocellular carcinoma growth

Hepatocellular carcinoma (HCC) is one of the most critical cancers; thus, novel therapeutical regimens are of great need. In this study, we investigated the effects of umbilical cord mesenchymal stem cells (UC-MSCs) derived exosomes on HepG2 cell line, and the underlying mechanism to control HCC proliferation, to identify the potential clinical role of exosomes as a novel molecular therapeutic target. Proliferation, apoptosis, and angiogenesis effects were assessed together with the cell viability evaluation by MTT assay in HepG2 cells at 24/48 h. with or without UC-MSCs-derived exosomes. Gene expressions of TNF-α, caspase-3, VEGF, stromal cell-derived factor-1 (SDF-1), and CX chemokine receptor-4 (CXCR-4) were measured by quantitative real-time PCR technique. Expression of sirtuin-1 (SIRT-1) protein was detected by western blot. Treatment of HepG2 cells with UC-MSCs-derived exosomes for 24 and 48 h. demonstrated a significant reduction of cells survival compared to the control group (p < 0.05). The SIRT-1 protein, and VEGF, SDF-1, CXCR-4 expression levels were significantly lower, TNF-α and caspase-3 expression levels were significantly higher in exosomal-treated HepG2 cells for 24 and 48 h. than those in the control group. Moreover, our findings documented that the anti-proliferative, apoptotic, and anti-angiogenic effects were achieved in a time-dependent manner in which more effects were determined after 48 h supplementation compared to 24 h (p < 0.05). UC-MSCs-derived exosomes exert anticarcinogenic molecular effects on HepG2 cells through the involvement of SIRT-1, SDF-1, and CXCR-4. Hence, exosomes would be a potential novel therapy regimen against HCC. Large-scale studies are recommended to verify this conclusion.

Identification of evolutionary mechanisms of myelomatous effusion by single-cell RNA sequencing

Myelomatous effusion (ME) is a rare manifestation of extramedullary multiple myeloma (MM) with limited therapeutic options and poor outcomes. The molecular mechanisms underlying ME are incompletely understood. We profiled transcriptomes of bone marrow, peripheral blood (PB), and pleural effusion/ascites from 3 patients with ME using single-cell RNA sequencing analysis. We found that ME contained a higher percentage of cytotoxic T cells, whereas PB contained a higher proportion of naive T cells. Malignant cells varied within and between sites and patients in their expression of signatures. We identified a gene module highly expressed in intramedullary and extramedullary plasma cell clusters and defined cell clusters expressing this gene set as extramedullary-initiating cells (EMICs). This gene set was associated with increased cellular proliferation, involved in p53 signaling, and related to poor prognosis in MM. The transcriptional regulators E2F1, YY1, and SMAD1 were activated in EMICs. Leukocyte immunoglobulin-like receptor subfamily B4 (LILRB4) was upregulated in extramedullary EMICs. We confirmed that LILRB4 promoted MM cell migration in vitro. This study provided insight into the evolutionary mechanisms of ME and defined EMICs and LILRB4 associated with extramedullary development.

Current and Future PET Imaging for Multiple Myeloma

Positron emission tomography (PET) is an imaging modality used for the noninvasive assessment of tumor staging and response to therapy. PET with 18F labeled fluorodeoxyglucose (18F-FDG PET) is widely used to assess the active and inactive lesions in patients with multiple myeloma (MM). Despite the availability of 18F-FDG PET for the management of MM, PET imaging is less sensitive than next-generation flow cytometry and sequencing. Therefore, the novel PET radiotracers 64Cu-LLP2A, 68Ga-pentixafor, and 89Zr-daratumumab have been developed to target the cell surface antigens of MM cells. Furthermore, recent studies attempted to visualize the tumor-infiltrating lymphocytes using PET imaging in patients with cancer to investigate their prognostic effect; however, these studies have not yet been performed in MM patients. This review summarizes the recent studies on PET with 18F-FDG and novel radiotracers for the detection of MM and the resulting preclinical research using MM mouse models and clinical studies. Novel PET technologies may be useful for developing therapeutic strategies for MM in the future.

CXC chemokine receptor 4 (CXCR4) blockade in cancer treatment

CXC chemokine receptor type 4 (CXCR4) is a member of the G protein-coupled receptors (GPCRs) superfamily and is specific for CXC chemokine ligand 12 (CXCL12, also known as SDF-1), which makes CXCL12/CXCR4 axis. CXCR4 interacts with its ligand, triggering downstream signaling pathways that influence cell proliferation chemotaxis, migration, and gene expression. The interaction also regulates physiological processes, including hematopoiesis, organogenesis, and tissue repair. Multiple evidence revealed that CXCL12/CXCR4 axis is implicated in several pathways involved in carcinogenesis and plays a key role in tumor growth, survival, angiogenesis, metastasis, and therapeutic resistance. Several CXCR4-targeting compounds have been discovered and used for preclinical and clinical cancer therapy, most of which have shown promising anti-tumor activity. In this review, we summarized the physiological signaling of the CXCL12/CXCR4 axis and described the role of this axis in tumor progression, and focused on the potential therapeutic options and strategies to block CXCR4.

Oncogenic Proteomics Approaches for Translational Research and HIV-Associated Malignancy Mechanisms

Recent advances in the field of proteomics have allowed extensive insights into the molecular regulations of the cell proteome. Specifically, this allows researchers to dissect a multitude of signaling arrays while targeting for the discovery of novel protein signatures. These approaches based on data mining are becoming increasingly powerful for identifying both potential disease mechanisms as well as indicators for disease progression and overall survival predictive and prognostic molecular markers for cancer. Furthermore, mass spectrometry (MS) integrations satisfy the ongoing demand for in-depth biomarker validation. For the purpose of this review, we will highlight the current developments based on MS sensitivity, to place quantitative proteomics into clinical settings and provide a perspective to integrate proteomics data for future applications in cancer precision medicine. We will also discuss malignancies associated with oncogenic viruses such as Acquire Immunodeficiency Syndrome (AIDS) and suggest novel mechanisms behind this phenomenon. Human Immunodeficiency Virus type-1 (HIV-1) proteins are known to be oncogenic per se, to induce oxidative and endoplasmic reticulum stresses, and to be released from the infected or expressing cells. HIV-1 proteins can act alone or in collaboration with other known oncoproteins, which cause the bulk of malignancies in people living with HIV-1 on ART.

CXCL12-CXCR4/CXCR7 Axis in Cancer: from Mechanisms to Clinical Applications

Cancer is a multi-step disease caused by the accumulation of genetic mutations and/or epigenetic changes, and is the biggest challenge around the world. Cytokines, including chemokines, exhibit expression changes and disorders in all human cancers. These cytokine abnormalities can disrupt homeostasis and immune function, and make outstanding contributions to various stages of cancer development such as invasion, metastasis, and angiogenesis. Chemokines are a superfamily of small molecule chemoattractive cytokines that mediate a variety of cellular functions. Importantly, the interactions of chemokine members CXCL12 and its receptors CXCR4 and CXCR7 have a broad impact on tumor cell proliferation, survival, angiogenesis, metastasis, and tumor microenvironment, and thus participate in the onset and development of many cancers including leukemia, breast cancer, lung cancer, prostate cancer and multiple myeloma. Therefore, this review aims to summarize the latest research progress and future challenges regarding the role of CXCL12-CXCR4/CXCR7 signaling axis in cancer, and highlights the potential of CXCL12-CXCR4/CXCR7 as a biomarker or therapeutic target for cancer, providing essential strategies for the development of novel targeted cancer therapies.

Theranostics in Hematooncology

In the early 2000s, major clinical trials provided evidence of a favorable outcome from antibody-mediated radioimmunotherapy for hematologic neoplasms, which then led to Food and Drug Administration approval. For instance, the theranostic armamentarium for the referring hematooncologist now includes ⁹⁰Y-ibritumomab tiuxetan for refractory low-grade follicular lymphoma or transformed B-cell non-Hodgkin lymphoma, as well as ¹³¹I-tositumomab for rituximab-refractory follicular lymphoma. Moreover, the first interim results of the SIERRA phase III trial reported beneficial effects from the use of ¹³¹I-anti-CD45 antibodies (Iomab-B) in refractory or relapsed acute myeloid leukemia. During the last decade, the concept of theranostics in hematooncology has been further expanded by C-X-C motif chemokine receptor 4-directed molecular imaging. Beyond improved detection rates of putative sites of disease, C-X-C motif chemokine receptor 4-directed PET/CT also selects candidates for radioligand therapy using β-emitting radioisotopes targeting the identical chemokine receptor on the lymphoma cell surface. Such image-piloted therapeutic strategies provided robust antilymphoma efficacy, along with desired eradication of the bone marrow niche, such as in patients with T- or B-cell lymphoma. As an integral part of the treatment plan, such radioligand therapy-mediated myeloablation also allows one to line up patients for stem cell transplantation, which leads to successful engraftment during the further treatment course. In this continuing education article, we provide an overview of the current advent of theranostics in hematooncology and highlight emerging clinical applications.

Polymorphisms within Autophagy-Related Genes as Susceptibility Biomarkers for Multiple Myeloma: A Meta-Analysis of Three Large Cohorts and Functional Characterization

Multiple myeloma (MM) arises following malignant proliferation of plasma cells in the bone marrow, that secrete high amounts of specific monoclonal immunoglobulins or light chains, resulting in the massive production of unfolded or misfolded proteins. Autophagy can have a dual role in tumorigenesis, by eliminating these abnormal proteins to avoid cancer development, but also ensuring MM cell survival and promoting resistance to treatments. To date no studies have determined the impact of genetic variation in autophagy-related genes on MM risk. We performed meta-analysis of germline genetic data on 234 autophagy-related genes from three independent study populations including 13,387 subjects of European ancestry (6863 MM patients and 6524 controls) and examined correlations of statistically significant single nucleotide polymorphisms (SNPs; p < 1 × 10-9) with immune responses in whole blood, peripheral blood mononuclear cells (PBMCs), and monocyte-derived macrophages (MDM) from a large population of healthy donors from the Human Functional Genomic Project (HFGP). We identified SNPs in six loci, CD46, IKBKE, PARK2, ULK4, ATG5, and CDKN2A associated with MM risk (p = 4.47 × 10-4-5.79 × 10-14). Mechanistically, we found that the ULK4rs6599175 SNP correlated with circulating concentrations of vitamin D3 (p = 4.0 × 10-4), whereas the IKBKErs17433804 SNP correlated with the number of transitional CD24+CD38+ B cells (p = 4.8 × 10-4) and circulating serum concentrations of Monocyte Chemoattractant Protein (MCP)-2 (p = 3.6 × 10-4). We also found that the CD46rs1142469 SNP correlated with numbers of CD19+ B cells, CD19+CD3- B cells, CD5+IgD- cells, IgM- cells, IgD-IgM- cells, and CD4-CD8- PBMCs (p = 4.9 × 10-4-8.6 × 10-4) and circulating concentrations of interleukin (IL)-20 (p = 0.00082). Finally, we observed that the CDKN2Ars2811710 SNP correlated with levels of CD4+EMCD45RO+CD27- cells (p = 9.3 × 10-4). These results suggest that genetic variants within these six loci influence MM risk through the modulation of specific subsets of immune cells, as well as vitamin D3-, MCP-2-, and IL20-dependent pathways.

Immune dysregulation in multiple myeloma: the current and future role of cell-based immunotherapy

Immune dysregulation is a hallmark of clinically active multiple myeloma (MM). Interactions between malignant clonal cells and immune cells within the bone marrow microenvironment are associated with the formation of a milieu favorable to tumor progression. IL-10, TGF-β and other immunoregulatory pathways are upregulated, promoting angiogenesis, tumor cell survival and inhibition of the native immune response. Transcriptomic evaluation of the bone marrow microenvironment reveals polarization of the T cell repertoire towards exhaustion and predominance of accessory cells with immunosuppressive qualities. These changes facilitate the immune escape of tumor cells and functional deficiencies that manifest as an increased risk of infection and a reduction in response to vaccinations. Immunotherapy with Chimeric Antigen Receptor (CAR) T cells and other cellular-based approaches have transformed outcomes for patients with advanced MM. Characterization of the immune milieu and identification of biomarkers predictive of treatment response are essential to increasing durability and allowing for the incorporation of novel strategies such as cancer vaccines. This paper will review the current use of cancer vaccines and CAR T cell therapy in MM as well as potential opportunities to expand and improve the application of these platforms.

Autophagy: A Potential Therapeutic Target to Tackle Drug Resistance in Multiple Myeloma

Multiple myeloma (MM) is the second most prevalent hematologic malignancy. In the past few years, the survival of MM patients has increased due to the emergence of novel drugs and combination therapies. Nevertheless, one of the significant obstacles in treating most MM patients is drug resistance, especially for individuals who have experienced relapses or developed resistance to such cutting-edge treatments. One of the critical processes in developing drug resistance in MM is autophagic activity, an intracellular self-digestive process. Several possible strategies of autophagy involvement in the induction of MM-drug resistance have been demonstrated thus far. In multiple myeloma, it has been shown that High mobility group box protein 1 (HMGB1)-dependent autophagy can contribute to drug resistance. Moreover, activation of autophagy via proteasome suppression induces drug resistance. Additionally, the effectiveness of clarithromycin as a supplemental drug in treating MM has been reported recently, in which autophagy blockage is proposed as one of the potential action mechanisms of CAM. Thus, a promising therapeutic approach that targets autophagy to trigger the death of MM cells and improve drug susceptibility could be considered. In this review, autophagy has been addressed as a survival strategy crucial for drug resistance in MM.

Effect of HPSE and HPSE2 SNPs on the Risk of Developing Primary Paraskeletal Multiple Myeloma

Multiple myeloma (MM) is a plasma cell malignancy that is accompanied by hypercalcemia, renal failure, anemia, and lytic bone lesions. Heparanase (HPSE) plays an important role in supporting and promoting myeloma progression, maintenance of plasma cell stemness, and resistance to therapy. Previous studies identified functional single nucleotide polymorphisms (SNPs) located in the HPSE gene. In the present study, 5 functional HPSE SNPs and 11 novel HPSE2 SNPs were examined. A very significant association between two enhancer (rs4693608 and rs4693084), and two insulator (rs4364254 and rs4426765) HPSE SNPs and primary paraskeletal disease (PS) was observed. SNP rs657442, located in intron 9 of the HPSE2 gene, revealed a significant protective association with primary paraskeletal disease and lytic bone lesions. The present study demonstrates a promoting (HPSE gene) and protective (HPSE2 gene) role of gene regulatory elements in the development of paraskeletal disease and bone morbidity. The effect of signal discrepancy between myeloma cells and normal cells of the tumor microenvironment is proposed as a mechanism for the involvement of heparanase in primary PS. We suggest that an increase in heparanase-2 expression can lead to effective suppression of heparanase activity in multiple myeloma accompanied by extramedullary and osteolytic bone disease.

A rare case report of waldenström macroglobulinemia converted to serum low IgM

Waldenström Macroglobulinemia (WM) is a rare chronic lymphoproliferative disease, accounting for less than 2% of hematological malignancies. It is characterized by plasma cytoid lymphocyte infiltration in bone marrow and abnormal increase of monoclonal IgM in peripheral blood. Only 5%-10% of cases of WM secrete monoclonal IgG and IgA components or do not secrete monoclonal long immunoglobulin. This case is the first to report of serum protein recombination from lgM and Igkappa band mutation to abnormal lgG and Igkappa band after 6 years of treatment in a male patient with WM.

Bone Marrow Mesenchymal Stem Cells (BMSC) Homing with Chemotaxis Transplantation of Stromal Cell-Derived Factor 1a Promotes the Corneal Damage Repair

This study analyzed the effect of bone marrow mesenchymal stem cells (BMSC) homing with chemotaxis transplantation of SDF-1a on the repair of corneal damage. The SDF-1a with varied concentration was added. They were divided into A group, B group, C group, D group and control group followed by analysis of corneal cell survival by MTT, apoptosis by flow cytometry, and Trkb level by immunohistochemical staining. There was an increasing tendency on the quantity of chemotactic cells (P <0.05) with a highest quantity in C group. The recruitment of BMSC could be prompted by SDF-1a and the chemotactic effect was the best when SDF-1a concentration was 100 ng/ml. The survival rate and Trkb protein level in experimental groups was higher than that in control group with highest survival rate and Trkb level in C group. In conclusion, corneal injury repair is prompted by BMSC homing with chemotaxis transplantation of SDF-1a, indicating that it might be used as a novel approach to promote corneal injury repair.

Molecular Crosstalk between Chromatin Remodeling and Tumor Microenvironment in Multiple Myeloma

Multiple myeloma (MM) is a complex disease driven by numerous genetic and epigenetic alterations that are acquired over time. Despite recent progress in the understanding of MM pathobiology and the availability of innovative drugs, which have pronounced clinical outcome, this malignancy eventually progresses to a drug-resistant lethal stage and, thus, novel therapeutic drugs/models always play an important role in effective management of MM. Modulation of tumor microenvironment is one of the hallmarks of cancer biology, including MM, which affects the myeloma genomic architecture and disease progression subtly through chromatin modifications. The bone marrow niche has a prime role in progression, survival, and drug resistance of multiple myeloma cells. Therefore, it is important to develop means for targeting the ecosystem between multiple myeloma bone marrow microenvironment and chromatin remodeling. Extensive gene expression profile analysis has indeed provided the framework for new risk stratification of MM patients and identifying novel molecular targets and therapeutics. However, key tumor microenvironment factors/immune cells and their interactions with chromatin remodeling complex proteins that drive MM cell growth and progression remain grossly undefined.

Machine intelligence-driven framework for optimized hit selection in virtual screening

Virtual screening (VS) aids in prioritizing unknown bio-interactions between compounds and protein targets for empirical drug discovery. In standard VS exercise, roughly 10% of top-ranked molecules exhibit activity when examined in biochemical assays, which accounts for many false positive hits, making it an arduous task. Attempts for conquering false-hit rates were developed through either ligand-based or structure-based VS separately; however, nonetheless performed remarkably well. Here, we present an advanced VS framework—automated hit identification and optimization tool (A-HIOT)—comprises chemical space-driven stacked ensemble for identification and protein space-driven deep learning architectures for optimization of an array of specific hits for fixed protein receptors. A-HIOT implements numerous open-source algorithms intending to integrate chemical and protein space leading to a high-quality prediction. The optimized hits are the selective molecules which we retrieve after extreme refinement implying chemical space and protein space modules of A-HIOT. Using CXC chemokine receptor 4, we demonstrated the superior performance of A-HIOT for hit molecule identification and optimization with tenfold cross-validation accuracies of 94.8% and 81.9%, respectively. In comparison with other machine learning algorithms, A-HIOT achieved higher accuracies of 96.2% for hit identification and 89.9% for hit optimization on independent benchmark datasets for CXCR4 and 86.8% for hit identification and 90.2% for hit optimization on independent test dataset for androgen receptor (AR), thus, shows its generalizability and robustness. In conclusion, advantageous features impeded in A-HIOT is making a reliable approach for bridging the long-standing gap between ligand-based and structure-based VS in finding the optimized hits for the desired receptor. The complete resource (framework) code is available at https://gitlab.com/neeraj-24/A-HIOT.

Graphical Abstract

Single cell characterization of myeloma and its precursor conditions reveals transcriptional signatures of early tumorigenesis

Multiple myeloma is a plasma cell malignancy almost always preceded by precursor conditions, but low tumor burden of these early stages has hindered the study of their molecular programs through bulk sequencing technologies. Here, we generate and analyze single cell RNA-sequencing of plasma cells from 26 patients at varying disease stages and 9 healthy donors. In silico dissection and comparison of normal and transformed plasma cells from the same bone marrow biopsy enables discovery of patient-specific transcriptional changes. Using Non-Negative Matrix Factorization, we discover 15 gene expression signatures which represent transcriptional modules relevant to myeloma biology, and identify a signature that is uniformly lost in abnormal cells across disease stages. Finally, we demonstrate that tumors contain heterogeneous subpopulations expressing distinct transcriptional patterns. Our findings characterize transcriptomic alterations present at the earliest stages of myeloma, providing insight into the molecular underpinnings of disease initiation.

Targeting CAM-DR and Mitochondrial Transfer for the Treatment of Multiple Myeloma

The prognosis of patients with multiple myeloma (MM) has improved dramatically with the introduction of new therapeutic drugs, but the disease eventually becomes drug-resistant, following an intractable and incurable course. A myeloma niche (MM niche) develops in the bone marrow microenvironment and plays an important role in the drug resistance mechanism of MM. In particular, adhesion between MM cells and bone marrow stromal cells mediated by adhesion molecules induces cell adhesion-mediated drug resistance (CAM-DR). Analyses of the role of mitochondria in cancer cells, including MM cells, has revealed that the mechanism leading to drug resistance involves exchange of mitochondria between cells (mitochondrial transfer) via tunneling nanotubes (TNTs) within the MM niche. Here, we describe the discovery of these drug resistance mechanisms and the identification of promising therapeutic agents primarily targeting CAM-DR, mitochondrial transfer, and TNTs.

Reduced CXCR4 expression in associated with extramedullary and predicts poor survival in newly diagnosed multiple myeloma

BACKGROUND

Multiple myeloma (MM), a bone marrow-resident hematological malignancy of plasma cells, has remained largely incurable despite the recent advancement in novel therapies. The heterogeneity of myeloma cells makes risk stratification of MM important for therapeutic regimen planning.

RESEARCH DESIGN AND METHODS

No immunohistochemical (IHC) predictive and prognostic marker of MM has been constructed yet. Herein, the prognostic value of chemokine (C-X-C motif) receptor 4 (CXCR4) expression in 48 newly diagnosed MM patients was explored using IHC. Correlations between CXCR4 expression and clinical features of MM were analyzed.

RESULTS

CXCR4-positive patients significantly outperformed CXCR4-negative patients in both 3-year estimated overall survival (93.8% vs 45.8%, P = 0.0392) and progression-free survival (57.1% vs 40.9%, P = 0.0436).

CONCLUSIONS

The incidence of extramedullary lesions in CXCR4-negative patients increased significantly compared with CXCR4-positive patients. Plasma cells that reduce CXCR4 expression have poor prognosis and increase the incidence of extramedullary lesions.

Patient-Derived Multiple Myeloma 3D Models for Personalized Medicine-Are We There Yet?

Despite the wide variety of existing therapies, multiple myeloma (MM) remains a disease with dismal prognosis. Choosing the right treatment for each patient remains one of the major challenges. A new approach being explored is the use of ex vivo models for personalized medicine. Two-dimensional culture or animal models often fail to predict clinical outcomes. Three-dimensional ex vivo models using patients' bone marrow (BM) cells may better reproduce the complexity and heterogeneity of the BM microenvironment. Here, we review the strengths and limitations of currently existing patient-derived ex vivo three-dimensional MM models. We analyze their biochemical and biophysical properties, molecular and cellular characteristics, as well as their potential for drug testing and identification of disease biomarkers. Furthermore, we discuss the remaining challenges and give some insight on how to achieve a more biomimetic and accurate MM BM model. Overall, there is still a need for standardized culture methods and refined readout techniques. Including both myeloma and other cells of the BM microenvironment in a simple and reproducible three-dimensional scaffold is the key to faithfully mapping and examining the relationship between these players in MM. This will allow a patient-personalized profile, providing a powerful tool for clinical and research applications.

Extramedullary Multiple Myeloma: A Patient-Focused Review of the Pathogenesis of Bone Marrow Escape

Multiple myeloma (MM) is a neoplastic clonal proliferation of plasma cells, predominantly in the bone marrow. The presentation of MM in extramedullary tissue, particularly the liver, is uncommon with only a few reported cases in literature. We report a rare and unusual presentation of kappa light chain restricted MM with progression of disease to involve the liver. MM was initially diagnosed on bone marrow biopsy, initially treated with carfilzomib, lenalidomide and dexamethasone, later changed to bortezomib, daratumumab and dexamethasone. There was subsequent progression with a new biopsy-proven myelomatous liver lesion. The patient could not receive high-dose chemotherapy due to multiple co-morbidities and extent of disease and eventually succumbed to her disease rapidly. This article emphasizes the poor prognosis of extramedullary involvement in MM and the pathogenic mechanisms by which it develops. Based on a review of the literature of other cases and case series of solitary or diffuse myeloma involvement in the liver, high-dose chemotherapy in combination with proteasome inhibitors and immunomodulators has the best success rate with less relapse and progressive disease in extramedullary myeloma. Our analysis concluded that the gain of CD44, loss of CD56, loss of very late antigen-4 (VLA-4), imbalance of the chemokine receptor-4-chemokine ligand-12 (CXCR4-CXCL12) axis, metastasis-associated lung adenocarcinoma 1 (MALAT1) upregulation, RAS pathway activation as well as 13q and 17p deletions show an increased propensity of malignant plasma cells to leave the bone marrow and hone in extramedullary sites giving rise to more aggressive extramedullary diseases. Targeted therapeutics such as CD44v-directed therapy and reactivation of p53 to wild-type conformation could potentially be evaluated as treatment options in the future to improve outcomes in this aggressive form of MM, especially in patients with advanced disease and limited treatment options.

Combination of chemically modified SDF-1α mRNA and small skin improves wound healing in diabetic rats with full-thickness skin defects

OBJECTIVES

Diabetes mellitus is associated with refractory wound healing, yet current therapies are insufficient to accelerate the process of healing. Recent studies have indicated chemically modified mRNA (modRNA) as a promising therapeutic intervention. The present study aimed to explore the efficacy of small skin engineered to express modified mRNAs encoding the stromal cell-derived factor-1α (SDF-1α) facilitating wound healing in a full-thickness skin defect rat model. This study, devised therapeutic strategies for diabetic wounds by pre-treating small skin with SDF-1α modRNA.

MATERIALS AND METHODS

The in vitro transfection efficiency was evaluated using fluorescence microscopy and the content of SDF-1α in the medium was determined using ELISA after the transfection of SDF-1α into the small skin. To evaluate the effect of SDF-1α modRNA and transplantation of the small skin cells on wound healing, an in vivo full-thickness skin defect rat model was assessed.

RESULTS

The results revealed that a modRNA carrying SDF-1α provided potent wound healing in the small skin lesions reducing reduced scar thickness and greater angiogenesis (CD31) in the subcutaneous layer. The SDF-1α cytokines were significantly secreted by the small skin after transfection in vitro.

CONCLUSIONS

This study demonstrated the benefits of employing small skin combined with SDF-1α modRNA in enhancing wound healing in diabetic rats having full-thickness skin defects.

Enhanced migration and immunoregulatory capacity of BMSCs mediated by overexpression of CXCR4 and IL-35

Bone marrow-derived mesenchymal stem cells (BMSCs) have been widely studied for their applications in immunoregulation and tissue repair. However, the therapeutic effects of BMSCs in the body are limited, partly due to the low homing efficiency of BMSCs to affected parts. The stromal cell-derived factor 1 (SDF-1)/C-X-C chemokine receptor type 4 (CXCR4) axis is well known to play an essential role in the homing of BMSCs. Interleukin 35 (IL-35) is a newly discovered cytokine confirmed to inhibit overactivated immune function and have a good therapeutic effect on autoimmune diseases. In this study, we innovatively developed dual gene modification of BMSCs by transducing CXCR4 and IL-35 and found that the migration and immunomodulatory activity of genetically engineered BMSCs were significantly enhanced compared to their natural counterparts. These results suggest that BMSCs modified by dual overexpression of CXCR4 and IL-35 may provide a potential treatment strategy for autoimmune diseases.

Molecular Impact of the Tumor Microenvironment on Multiple Myeloma Dissemination and Extramedullary Disease

Multiple myeloma (MM) is the most common malignant monoclonal disease of plasma cells. Aside from classical chemotherapy and glucocorticoids, proteasome inhibitors, immunomodulatory agents and monoclonal antibodies are used in the current treatment scheme of MM. The tumor microenvironment (TME) plays a fundamental role in the development and progression of numerous solid and non-solid cancer entities. In MM, the survival and expansion of malignant plasma cell clones heavily depends on various direct and indirect signaling pathways provided by the surrounding bone marrow (BM) niche. In a number of MM patients, single plasma cell clones lose their BM dependency and are capable to engraft at distant body sites or organs. The resulting condition is defined as an extramedullary myeloma (EMM). EMMs are highly aggressive disease stages linked to a dismal prognosis. Emerging literature demonstrates that the dynamic interactions between the TME and malignant plasma cells affect myeloma dissemination. In this review, we aim to summarize how the cellular and non-cellular BM compartments can promote plasma cells to exit their BM niche and metastasize to distant intra-or extramedullary locations. In addition, we list selected therapy concepts that directly target the TME with the potential to prevent myeloma spread.

Nanobodies in the limelight: Multifunctional tools in the fight against viruses

Antibodies are natural antivirals generated by the vertebrate immune system in response to viral infection or vaccination. Unsurprisingly, they are also key molecules in the virologist's molecular toolbox. With new developments in methods for protein engineering, protein functionalization and application, smaller antibody-derived fragments are moving in focus. Among these, camelid-derived nanobodies play a prominent role. Nanobodies can replace full-sized antibodies in most applications and enable new possible applications for which conventional antibodies are challenging to use. Here we review the versatile nature of nanobodies, discuss their promise as antiviral therapeutics, for diagnostics, and their suitability as research tools to uncover novel aspects of viral infection and disease.