The genetic architecture of multiple myeloma

Chromosomal defects in multiple myeloma

Multiple myeloma is a plasma cell neoplasm driven by primary (e.g. hyperdiploidy; IGH translocations) and secondary (e.g. 1q21 gains/amplifications; del(17p); MYC translocations) chromosomal events. These are important to detect as they influence prognosis, therapeutic response and disease survival. Currently, cytogenetic testing is most commonly performed by interphase fluorescence in situ hybridisation (FISH) on aspirated bone marrow samples. A number of variations to FISH methodology are available, including prior plasma cell enrichment and incorporation of immunophenotypic plasma cell identification. Other molecular methods are increasingly being utilised to provide a genome-wide view at high resolution (e.g. single nucleotide polymorphism (SNP) microarray analysis) and these can detect abnormalities in most cases. Despite their wide application at diagnostic assessment, both FISH and SNP-array have relatively low sensitivity, limiting their use for identification of prognostically significant low-level sub-clones or for disease monitoring. Next-generation sequencing is increasingly being used to detect mutations and new FISH techniques such as by flow cytometry are in development and may address some of the current test limitations. Here we review the primary and secondary cytogenetic aberrations in myeloma and discuss the range of techniques available for their assessment.

Mechanical properties, and in vitro biocompatibility assessment of biomimetic dual layered keratin/ hydroxyapatite scaffolds

A novel biomimetic dual layered keratin/hydroxyapatite (keratin/HA) scaffold was designed using iterative freeze-drying technique. The prepared scaffolds were studied using several analytical techniques to better understand the biological, structural, and mechanical properties. The developed multilayered, interconnected, porous keratin scaffold with different hydroxyapatite (HA) content in the outer and inner layer, mimics the inherent gradient structure of alveolar bone. SEM studies showed an interconnected porous architecture of the prepared scaffolds with seamless integration between the upper and lower layers. The incorporation of HA improved the mechanical properties keratin/HA scaffolds. The keratin/HA scaffolds exhibited superior mechanical properties in terms of Young's modulus and compressive strength in comparison to pure keratin scaffolds. The biocompatibility studies suggested that both keratin and keratin/HA scaffolds were cyto-compatible, in terms of cell proliferation. Furthermore, it showed that both the tested materials can served as an ideal substrate for the differentiation of Saos-2 cells, leading to mineralization of the extracellular matrix. In summary, ionic liquid based green technique was employed for keratin extraction to fabricate keratin/HA scaffolds and our detailed in vitro investigations suggest the great potential for these composite scaffolds for bone tissue engineering in future.

Molecular genetic aberrations in the pathogenesis of multiple myeloma

Multiple myeloma (MM) is the second most common form of blood cancer characterized by clonal expansion of malignant plasma cells within the bone marrow. MM is a complex, progressive, and highly heterogeneous malignancy, which occurs via a multistep transformation process involving primary and secondary oncogenic events. Recent advances in molecular techniques have further expanded our understanding of the mutational landscape, clonal composition, and dynamic evolution patterns of MM. The first part of this review describes the key oncogenic events involved in the initiation and progression of MM, together with their prognostic impact. The latter part highlights the most prominent findings concerning genomic aberrations promoted by gene expression profiling (GEP) and next-generation sequencing (NGS) in MM. This review provides a concise understanding of the molecular pathogenesis of the MM genome and the importance of adopting emerging molecular technology in future clinical management of MM.

Proteomic Alteration in the Progression of Multiple Myeloma: A Comprehensive Review

Multiple myeloma (MM) is an incurable hematologic malignancy. Most MM patients are diagnosed at a late stage because the early symptoms of the disease can be uncertain and nonspecific, often resembling other, more common conditions. Additionally, MM patients are commonly associated with rapid relapse and an inevitable refractory phase. MM is characterized by the abnormal proliferation of monoclonal plasma cells in the bone marrow. During the progression of MM, massive genomic alterations occur that target multiple signaling pathways and are accompanied by a multistep process involving differentiation, proliferation, and invasion. Moreover, the transformation of healthy plasma cell biology into genetically heterogeneous MM clones is driven by a variety of post-translational protein modifications (PTMs), which has complicated the discovery of effective treatments. PTMs have been identified as the most promising candidates for biomarker detection, and further research has been recommended to develop promising surrogate markers. Proteomics research has begun in MM, and a comprehensive literature review is available. However, proteomics applications in MM have yet to make significant progress. Exploration of proteomic alterations in MM is worthwhile to improve understanding of the pathophysiology of MM and to search for new treatment targets. Proteomics studies using mass spectrometry (MS) in conjunction with robust bioinformatics tools are an excellent way to learn more about protein changes and modifications during disease progression MM. This article addresses in depth the proteomic changes associated with MM disease transformation.

FAM46C-mediated tumor heterogeneity predicts extramedullary metastasis and poorer survival in multiple myeloma

Cancers originate from a single cell according to Nowell's theory of clonal evolution. The enrichment of the most aggressive clones has been developed and the heterogeneity arises for genomic instability and environmental selection. Multiple myeloma (MM) is a multiple relapse plasma cell cancer generated from bone marrow. Although there were accumulating researches in multiple myeloma pathogenesis, the heterogeneity remains poorly understood. The participants enrolled in this study were 4 EMP+ (EMP, Extramedullary plasmacytoma) and 2 EMP- primarily untreated MM patients. Single cell RNA sequencing and analysis were conducted for the single cell suspension, which was sorted by flow cytometry from peripheral blood mononuclear cells or bone marrow cells. In our research, the results of single cell RNA sequencing show that FAM46C determines MM tumor heterogeneity predicting extramedullary metastasis by influencing RNA stability. Further, we integrated and analyzed 2280 multiple myeloma samples from 7 independent datasets, which uncover that FAM46C mediated tumor heterogeneity predicts poorer survival in multiple myeloma.

MST1 DOWNREGULATES TAZ TUMOUR SUPPRESSOR PROTEIN IN MULTIPLE MYELOMA AND IS A POTENTIAL THERAPEUTIC TARGET

We have previously reported that TAZ functions as a tumor suppressor in multiple myeloma. MST1 is a serine-threonine kinase upstream of the Hippo-signaling pathway that functions as a tumor suppressor in many non-haematological malignancies. However, its role in hematological malignancies, including MM is still poorly understood. In this paper, we provide evidence that MST1 expression is higher in MM, and negatively correlates with TAZ expression in both cell lines and patient samples. High MST1 expression was associated with poor clinical outcomes. Genetic or pharmacological inhibition of MST1 leads to increased TAZ expression and cell death. Importantly, MST1 inhibitors sensitizes myeloma cells to frontline antimyeloma agent-lenalidomide and dexamethasone. Taken together, our data reveals a key role for MST1 in MM pathogenesis and provide evidence to explore the therapeutic potential of using MST inhibitors to upregulate TAZ expression in MM to promote response to anticancer agents.

Survival analysis of transplant-eligible newly-diagnosed multiple myeloma patients harboring t(4;14), t(14;16), and/or del(17p) in the real-world setting

Cytogenetic abnormalities (CA) such as t(4;14), t(14;16), and del(17p), are associated with a poor prognosis in Multiple Myeloma (MM) patients. However, there is scarce information regarding the Latin-American population. This study aims to analyze the impact of t(4;14), t(14;16), and del(17p) on the progression-free survival (PFS) and overall survival (OS) of transplant-eligible newly-diagnosed MM (NDMM) patients in Latin America. Retrospective survival analysis based on the Grupo de Estudio Latinoamericano de MM (GELAMM) registry, including all adult patients with NDMM harboring CA t(4;14), t(14;16), and/or del(17p). Fifty-nine patients were included; the median age was 57 years, 55.9% males, 22% ISS-I, 25.4% ISS-II, and 47.5% ISS-III. The majority (89.8%) had one alteration, whereas 10.2% had del(17p) and t(4;14). The frequencies of CA were del(17p) in 61.0%, t(4;14) in 25.4%, and t(14;16) in 3,4%. Autologous stem cell transplantation was performed in 36 cases, 20 patients did not use this consolidative strategy, and this data was missed in three cases. Five-year OS for the entire cohort was 60.8% and 5-year PFS was 28.1%. Bortezomib-based induction regimen (BBR) (p=0.029), consolidation with ASCT (p<0.001), and maintenance therapy (p=0.004) were associated with an improved 5-year OS. In the multivariate analysis, ASCT was the only variable with a positive impact on OS (HR 0.11, 95% CI 0.033 to 0.34, p<0.001). The median PFS presented a non-statistically significant benefit in BBR, ASCT, and maintenance therapy groups. BBR induction, ASCT, and maintenance therapy were associated with improved OS in high-risk NDMM patients.

Treatment Strategies for Multiple Myeloma Treatment and the Role of High-Throughput Screening for Precision Cancer Therapy

In the past few years, development of approved drug candidates has improved the disease management of multiple myeloma (MM). However, due to drug resistance, some of the patients do not respond positively, while some of the patients acquire drug resistance, thereby these patients eventually relapse. Hence, there are no other therapeutic options for multiple myeloma patients. Therefore, this necessitates a precision-based approach to multiple myeloma therapy. The use of patient's samples to test drug sensitivity to increase efficacy and reduce treatment-related toxicities is the goal of functional precision medicine. Platforms such as high-throughput-based drug repurposing technology can be used to select effective single drug and drug combinations based on the efficacy and toxicity studies within a time frame of couple of weeks. In this article, we describe the clinical and cytogenetic features of MM. We highlight the various treatment strategies and elaborate on the role of high-throughput screening platforms in a precision-based approach towards clinical treatment.

A Novel Integrated Approach for Cytogenomic Evaluation of Plasma Cell Neoplasms

Plasma cell neoplasm (PCN) is associated with characteristic chromosomal aberrations of diagnostic and prognostic significance. The presence of a small percentage of neoplastic cells is a drawback in the application of karyotyping and fluorescence in situ hybridization for the evaluation of bone marrow aspirate. The analysis of samples enriched for CD138⁺ cells has improved the detection rate. However, fluorescence in situ hybridization requires several probes and may not be completed due to a limited number of isolated cells. To address the issues experienced with the conventional approach, a novel integrated protocol that consists of whole-genome amplification of DNA isolated from CD138⁺ cells, followed by microarray as well as one fluorescence in situ hybridization assay for balanced IGH gene rearrangements, has been developed. In the present study in a cohort of 56 patients with clinical suspicion for PCN, compared to conventional cytogenetic analysis, this approach provided higher yield in the detection of PCN-related abnormalities, irrespective of the initial percentage of plasma cells. Whole-genome profiling uncovered recurrent chromosomal abnormalities of prognostic value, including unbalanced alterations within the MYC locus, 16q loss, and hypodiploidy, that were not otherwise detectable by conventional methods. The proposed approach is cost-efficient and provides a superior detection rate, required for proper risk stratification and differential diagnosis of PCN regardless of initial plasma cell percentage.

Calorie restriction has no effect on bone marrow tumour burden in a Vk*MYC transplant model of multiple myeloma

Multiple myeloma (MM) is an incurable haematological malignancy, caused by the uncontrolled proliferation of plasma cells within the bone marrow (BM). Obesity is a known risk factor for MM, however, few studies have investigated the potential of dietary intervention to prevent MM progression. Calorie restriction (CR) is associated with many health benefits including reduced cancer incidence and progression. To investigate if CR could reduce MM progression, dietary regimes [30% CR, normal chow diet (NCD), or high fat diet (HFD)] were initiated in C57BL/6J mice. Diet-induced changes were assessed, followed by inoculation of mice with Vk*MYC MM cells (Vk14451-GFP) at 16 weeks of age. Tumour progression was monitored by serum paraprotein, and at endpoint, BM and splenic tumour burden was analysed by flow cytometry. 30% CR promoted weight loss, improved glucose tolerance, increased BM adiposity and elevated serum adiponectin compared to NCD-fed mice. Despite these metabolic changes, CR had no significant effect on serum paraprotein levels. Furthermore, endpoint analysis found that dietary changes were insufficient to affect BM tumour burden, however, HFD resulted in an average two-fold increase in splenic tumour burden. Overall, these findings suggest diet-induced BM changes may not be key drivers of MM progression in the Vk14451-GFP transplant model of myeloma.

The Role of Long Non-coding RNA, Nuclear Enriched Abundant Transcript 1 (NEAT1) in Cancer and Other Pathologies

Nuclear enriched abundant transcript 1 (NEAT1), consisting of two kinds of lncRNAs of 3.7 kB NEAT1-1 and 23 kB NEAT1-2, can be highly expressed in organs and tissues such as the ovary, prostate, colon, and pancreas, and is involved in paraspeckle formation and mRNA editing and gene expression. Therefore, NEAT1 is a potential biomarker for the treatment of a variety of diseases, which may be caused by two factors (isoforms of NEAT1 and NEAT1 sponging miRNA as ceRNA). However, there is still much confusion about the mechanism and downstream effector between the abnormal expression of NEAT1 and various diseases. This review summarizes recent research progress on NEAT1 in cancer and other pathologies and provides a more reliable theoretical basis for the treatment of related diseases.

Landscape of functional interactions of human processive ribonucleases revealed by high-throughput siRNA screenings

Processive exoribonucleases are executors of RNA decay. In humans, their physical but not functional interactions were thoughtfully investigated. Here we have screened cells deficient in DIS3, XRN2, EXOSC10, DIS3L, and DIS3L2 with a custom siRNA library and determined their genetic interactions (GIs) with diverse pathways of RNA metabolism. We uncovered a complex network of positive interactions that buffer alterations in RNA degradation and reveal reciprocal cooperation with genes involved in transcription, RNA export, and splicing. Further, we evaluated the functional distinctness of nuclear DIS3 and cytoplasmic DIS3L using a library of all known genes associated with RNA metabolism. Our analysis revealed that DIS3 mutation suppresses RNA splicing deficiency, while DIS3L GIs disclose the interplay of cytoplasmic RNA degradation with nuclear RNA processing. Finally, genome-wide DIS3 GI map uncovered relations with genes not directly involved in RNA metabolism, like microtubule organization or regulation of telomerase activity.

DMG26: A Targeted Sequencing Panel for Mutation Profiling to Address Gaps in the Prognostication of Multiple Myeloma

Multiple myeloma presents with numerous primary genomic lesions that broadly dichotomize cases into hyperdiploidy or IgH translocated. Clinically, these large alterations are assessed by fluorescence in situ hybridization (FISH) for risk stratification at diagnosis. Secondary focal events, including indels and single-nucleotide variants, are also reported; however, their clinical correlates are poorly described, and FISH has insufficient resolution to assess many of them. In this study, we examined the exonic sequences of 26 genes reported to be mutated in >1% of patients with myeloma using a custom panel. We sequenced these exons to approximately 1000 times in a cohort of 76 patients from Atlantic Canada with detailed clinical correlates and in four multiple myeloma cell lines. Across the 76 patients, 255 mutations and 33 focal copy number variations were identified. High-severity mutations and mutations predicted by FATHMM-XF to be pathogenic identified patients with significantly reduced progression-free survival. These mutations were mutually exclusive from the Revised International Staging System high-risk FISH markers and were independent of all biochemical parameters of the Revised International Staging System. Applying our panel to patients classified by FISH to be standard risk successfully reclassified patients into high- and standard-risk groups. Furthermore, three patients in our cohort each had two high-risk markers; two of these patients developed plasma cell leukemia, a rare and severe clinical sequela of multiple myeloma.

Network-Based Systems Analysis Explains Sequence-Dependent Synergism of Bortezomib and Vorinostat in Multiple Myeloma

Bortezomib and vorinostat exhibit synergistic effects in multiple myeloma (MM) cells when given in sequence, and the purpose of this study was to evaluate the molecular determinants of the interaction using a systems pharmacology approach. A Boolean network model consisting of 79 proteins and 225 connections was developed using literature information characterizing mechanisms of drug action and intracellular signal transduction. Network visualization and structural analysis were conducted, and model simulations were compared with experimental data. Critical biomarkers, such as pNFκB, p53, cellular stress, and p21, were identified using measures of network centrality and model reduction. U266 cells were then exposed to bortezomib (3 nM) and vorinostat (2 μM) as single agents or in simultaneous and sequential (bortezomib for first 24 h, followed by addition of vorinostat for another 24 h) combinations. Temporal changes for nine of the critical proteins in the reduced Boolean model were measured over 48 h, and cellular proliferation was measured over 96 h. A mechanism-based systems model was developed that captured the biological basis of a bortezomib and vorinostat sequence-dependent pharmacodynamic interaction. The model was further extended in vivo by linking in vitro parameter values and dynamics of p21, caspase-3, and pAKT biomarkers to tumor growth in xenograft mice reported in the literature. Network-based methodologies and pharmacodynamic principles were integrated successfully to evaluate bortezomib and vorinostat interactions in a mechanistic and quantitative manner. The model can be potentially applied to evaluate their combination regimens and explore in vivo dosing regimens.

A Comprehensive Review of the Genomics of Multiple Myeloma: Evolutionary Trajectories, Gene Expression Profiling, and Emerging Therapeutics

Multiple myeloma (MM) is a blood cancer characterized by the accumulation of malignant monoclonal plasma cells in the bone marrow. It develops through a series of premalignant plasma cell dyscrasia stages, most notable of which is the Monoclonal Gammopathy of Undetermined Significance (MGUS). Significant advances have been achieved in uncovering the genomic aberrancies underlying the pathogenesis of MGUS-MM. In this review, we discuss in-depth the genomic evolution of MM and focus on the prognostic implications of the accompanied molecular and cytogenetic aberrations. We also dive into the latest investigatory techniques used for the diagnoses and risk stratification of MM patients.

Hyperdiploid Multiple Myeloma with Novel Complex Structural Chromosome Abnormalities Associated with Poor Prognosis : A Rare Case Report

Hyperdiploid multiple myeloma (MM) is associated with better prognosis and non-hyperdiploid subtype is associated with variable to adverse prognosis based on the nature of karyotype abnormality.  Rarely exceptions to this hyperdiploid and non-hyperdiploid divisions do exist in a minority. We report an adult male MM patient who showed hyperdiploid karyotype with few novel complex abnormalities and who showed poor clinical outcome. Conventional cytogenetic analysis carried out in 22 GTG banded metaphases showed 53,Y,der(X)t(X;22)(q27;q11.2),+3,+5,+6,+9,+11,+15,der(17)ins(17;1;3)(q11.2;?;?),der(17)ins(17;1;3)(q11.2;?;?),+19,-22,+mar karyotype pattern in 15 metaphases whereas 7 metaphases showed 46,XY karyotype  pattern.  Interphase FISH revealed biallelic del(13q14) and del(17p13) but no translocations involving the 14q32 region. Through Spectral karyotyping FISH, the origin of complex abnormalities involving der(17) chromosome,  translocation t(X;22), and marker chromosome could be clearly delineated. Although the present case showed hyperdiploid karyotype, he showed an adverse prognosis probably due to the co-existence of high risk and complex abnormalities and expired 5 months after initial diagnosis despite standard treatment given.

The Immunity-malignancy equilibrium in multiple myeloma: lessons from oncogenic events in plasma cells

Multiple myeloma (MM) is a malignancy of plasma cells (PC) that grow within the bone marrow and maintain massive immunoglobulin (Ig) production. Disease evolution is driven by genetic lesions, whose effects on cell biology and fitness underlie addictions and vulnerabilities of myeloma cells. Several genes mutated in myeloma are strictly involved in dictating PC identity and antibody factory function. Here, we evaluate the impact of mutations in IRF4, PRDM1, and XBP1, essential transcription factors driving the B to PC differentiation, on MM cell biology and homeostasis. These factors are highly specialized, with limited overlap in their downstream transcriptional programs. Indeed, IRF4 sustains metabolism, survival, and proliferation, while PRDM1 and XBP1 are mainly responsible for endoplasmic reticulum expansion and sustained Ig secretion. Interestingly, IRF4 undergoes activating mutations and translocations, while PRDM1 and XBP1 are hit by loss-of-function events, raising the hypothesis that containment of the secretory program, but not its complete extinction, may be beneficial to malignant PCs. Finally, recent studies unveiled that also the PRDM1 target, FAM46C/TENT5C, an onco-suppressor uniquely and frequently mutated or deleted in myeloma, is directly and potently involved in orchestrating ER homeostasis and secretory activity. Inactivating mutations found in this gene and its interactors strengthen the notion that reduced secretory capacity confers advantage to myeloma cells. We believe that dissection of the evolutionary pressure on genes driving PC-specific functions in myeloma will disclose the cellular strategies by which myeloma cells maintain an equilibrium between antibody production and survival, thus unveiling novel therapeutic targets.

Co-evolution of tumor and immune cells during progression of multiple myeloma

Multiple myeloma (MM) is characterized by the uncontrolled proliferation of plasma cells. Despite recent treatment advances, it is still incurable as disease progression is not fully understood. To investigate MM and its immune environment, we apply single cell RNA and linked-read whole genome sequencing to profile 29 longitudinal samples at different disease stages from 14 patients. Here, we collect 17,267 plasma cells and 57,719 immune cells, discovering patient-specific plasma cell profiles and immune cell expression changes. Patients with the same genetic alterations tend to have both plasma cells and immune cells clustered together. By integrating bulk genomics and single cell mapping, we track plasma cell subpopulations across disease stages and find three patterns: stability (from precancer to diagnosis), and gain or loss (from diagnosis to relapse). In multiple patients, we detect “B cell-featured” plasma cell subpopulations that cluster closely with B cells, implicating their cell of origin. We validate AP-1 complex differential expression (JUN and FOS) in plasma cell subpopulations using CyTOF-based protein assays, and integrated analysis of single-cell RNA and CyTOF data reveals AP-1 downstream targets (IL6 and IL1B) potentially leading to inflammation regulation. Our work represents a longitudinal investigation for tumor and microenvironment during MM progression and paves the way for expanding treatment options.

Clonal evolution in multiple myeloma (MM) needs to be understood in both the tumor and its microenvironment. Here the authors perform single-cell multi-omics profiling of samples from MM patients at different stages, finding transitions in the immune cell composition throughout progression.

Genetic Predictors of Mortality in Patients with Multiple Myeloma

Multiple myeloma (MM) is a heterogeneous disease featured by clonal plasma cell proliferation and genomic instability. The advent of next-generation sequencing allowed unraveling the complex genomic landscape of the disease. Several recurrent genomic aberrations including immunoglobulin genes translocations, copy number abnormalities, complex chromosomal events, transcriptomic and epigenomic deregulation, and mutations define various molecular subgroups with distinct outcomes. In this review, we describe the recurrent genomic events identified in MM impacting patients’ outcome and survival. These genomic aberrations constitute new markers that could be incorporated into a prognostication model to eventually guide therapy at every stage of the disease.

The Role of lncRNAs in the Pathobiology and Clinical Behavior of Multiple Myeloma

Simple Summary

Multiple myeloma (MM), the second most common hematological neoplasm, is still considered an incurable disease. Long non-coding RNAs (lncRNAs), genes that do not encode proteins, participate in numerous biological processes, but their deregulation, like that of coding genes, can contribute to carcinogenesis. Increasing evidence points to the relevant role of lncRNAs in the development of human tumors, such that they emerge as attractive biomarkers and therapeutic targets for cancer treatment, including MM. Here we review the oncogenic or tumor-suppressor functions of lncRNAs in MM and provide an overview of novel therapeutic approaches based on lncRNAs that will help to improve the management of these patients.

Abstract

MM is a hematological neoplasm that is still considered an incurable disease. Besides established genetic alterations, recent studies have shown that MM pathogenesis is also characterized by epigenetic aberrations, such as the gain of de novo active chromatin marks in promoter and enhancer regions and extensive DNA hypomethylation of intergenic regions, highlighting the relevance of these non-coding genomic regions. A recent study described how long non-coding RNAs (lncRNAs) correspond to 82% of the MM transcriptome and an increasing number of studies have demonstrated the importance of deregulation of lncRNAs in MM. In this review we focus on the deregulated lncRNAs in MM, including their biological or functional mechanisms, their role as biomarkers to improve the prognosis and monitoring of MM patients, and their participation in drug resistance. Furthermore, we also discuss the evidence supporting the role of lncRNAs as therapeutic targets through different novel RNA-based strategies.

Durvalumab Combined with Immunomodulatory Drugs (IMiD) Overcomes Suppression of Antitumor Responses due to IMiD-induced PD-L1 Upregulation on Myeloma Cells

We previously showed that the interaction of programmed death-ligand 1 (PD-L1) on multiple myeloma (MM) cells with PD-1 not only inhibits tumor-specific cytotoxic T-lymphocyte activity via the PD-1 signaling pathway but also induces drug resistance via PD-L1-mediated reverse signals. We here examined the regulation of PD-L1 expression by immunomodulatory drugs (IMiDs) and antimyeloma effects of the anti-PD-L1 antibody durvalumab in combination with IMiDs. IMiDs induced PD-L1 expression on IMiD-insensitive MM cells and plasma cells from patients newly diagnosed with MM. Gene-expression profiling analysis demonstrated that not only PD-L1, but also a proliferation-inducing ligand (APRIL), was enhanced by IMiDs. PD-L1 induction by IMiDs was suppressed by using the APRIL inhibitor recombinant B-cell maturation antigen (BCMA)-Ig, the antibody against BCMA, or an MEK/ERK inhibitor in in vitro and in vivo assays. In addition, its induction was abrogated in cereblon (CRBN)-knockdown MM cells, whereas PD-L1 expression was increased and strongly induced by IMiDs in Ikaros-knockdown cells. These results demonstrated that PD-L1 upregulation by IMiDs on IMiD-insensitive MM cells was induced by (i) the BCMA-APRIL pathway via IMiD-mediated induction of APRIL and (ii) Ikaros degradation mediated by CRBN, which plays a role in inhibiting PD-L1 expression. Furthermore, T-cell inhibition induced by PD-L1-upregulated cells was effectively recovered after combination treatment with durvalumab and IMiDs. PD-L1 upregulation by IMiDs on MM cells might promote aggressive myeloma behaviors and immune escape in the bone marrow microenvironment.

Identification and Validation of a Potential Prognostic 7-lncRNA Signature for Predicting Survival in Patients with Multiple Myeloma

BACKGROUND

An increasing number of studies have indicated that the abnormal expression of certain long noncoding RNAs (lncRNAs) is linked to the overall survival (OS) of patients with myeloma.

METHODS

Gene expression data of myeloma patients were downloaded from the Gene Expression Omnibus (GEO) database (GSE4581 and GSE57317). Cox regression analysis, Kaplan-Meier, and receiver operating characteristic (ROC) analysis were performed to construct and validate the prediction model. Single sample gene set enrichment (ssGSEA) and Kyoto Encyclopedia of Genes and Genomes (KEGG) analysis were used to predict the function of a specified lncRNA.

RESULTS

In this study, a seven-lncRNA signature was identified and used to construct a risk score system for myeloma prognosis. This system was used to stratify patients with different survival rates in the training set into high-risk and low-risk groups. Test set, the entire test set, the external validation set, and the myeloma subtype achieved the authentication of the results. In addition, functional enrichment analysis indicated that 7 prognostic lncRNAs may be involved in the tumorigenesis of myeloma through cancer-related pathways and biological processes. The results of the immune score showed that IF_I was negatively correlated with the risk score. Compared with the published gene signature, the 7-lncRNA model has a higher C-index (above 0.8).

CONCLUSION

In summary, our data provide evidence that seven lncRNAs could be used as independent biomarkers to predict the prognosis of myeloma, which also indicated that these 7 lncRNAs may be involved in the progression of myeloma.

Differential RNA splicing as a potentially important driver mechanism in multiple myeloma

Disruption of the normal splicing patterns of RNA is a major factor in the pathogenesis of a number of diseases. Increasingly research has shown the strong influence that splicing patterns can have on cancer progression. Multiple Myeloma is a molecularly heterogeneous disease classified by the presence of key translocations, gene expression profiles and mutations but the splicing patterns in MM remains largely unexplored. We take a multifaceted approach to define the extent and impact of alternative splicing in MM. We look at the spliceosome component, SF3B1, with hotspot mutations (K700E and K666T/Q) shown to result in an increase in alternative splicing in other cancers. We discovered a number of differentially spliced genes in comparison of the SF3B1 mutant and wild type samples that included, MZB1, DYNLL1, TMEM14C and splicing related genes DHX9, CLASRP, and SNRPE. We identified a broader role for abnormal splicing showing clear differences in the extent of novel splice variants in the different translocation groups. We show that a high number of novel splice loci is associated with adverse survival and an ultra-high risk group. The enumeration of patterns of alternative splicing has the potential to refine MM classification and to aid in the risk stratification of patients.

Morphogens and growth factor signalling in the myeloma bone-lining niche

Multiple myeloma is a malignancy caused by the clonal expansion of abnormal plasma cells. Myeloma cells have proven to be incredibly successful at manipulating their microenvironment to promote growth and to evade modern therapies. They have evolved to utilise the integral signalling pathways of the bone and bone marrow to drive disease progression. The bone marrow is often described in the context of a single structure that fills the bone cavity and supports normal haematopoiesis. However, within that structure exists two anatomically different niches, the perivascular niche and the endosteal niche. These contain different cell types functioning to support normal immune and blood cell production as well as healthy bone. These cells secrete numerous signalling molecules that can influence myeloma cell biology and behaviour. The endosteal niche is home to specific bone cell lineages and plays a pivotal role in myeloma cell establishment and survival. This review will concentrate on some of the signalling pathways that are hijacked by myeloma cells to shape a favourable environment, and the different influences myeloma cells are exposed to depending on their spatial location within the bone marrow.

Prognostic value of integrated cytogenetic, somatic variation, and copy number variation analyses in Korean patients with newly diagnosed multiple myeloma

BACKGROUND

To investigate the prognostic value of gene variants and copy number variations (CNVs) in patients with newly diagnosed multiple myeloma (NDMM), an integrative genomic analysis was performed.

METHODS

Sixty-seven patients with NDMM exhibiting more than 60% plasma cells in the bone marrow aspirate were enrolled in the study. Whole-exome sequencing was conducted on bone marrow nucleated cells. Mutation and CNV analyses were performed using the CNVkit and Nexus Copy Number software. In addition, karyotype and fluorescent in situ hybridization were utilized for the integrated analysis.

RESULTS

Eighty-three driver gene mutations were detected in 63 patients with NDMM. The median number of mutations per patient was 2.0 (95% confidence interval [CI] = 2.0-3.0, range = 0-8). MAML2 and BHLHE41 mutations were associated with decreased survival. CNVs were detected in 56 patients (72.7%; 56/67). The median number of CNVs per patient was 6.0 (95% CI = 5.7-7.0; range = 0-16). Among the CNVs, 1q gain, 6p gain, 6q loss, 8p loss, and 13q loss were associated with decreased survival. Additionally, 1q gain and 6p gain were independent adverse prognostic factors. Increased numbers of CNVs and driver gene mutations were associated with poor clinical outcomes. Cluster analysis revealed that patients with the highest number of driver mutations along with 1q gain, 6p gain, and 13q loss exhibited the poorest prognosis.

CONCLUSIONS

In addition to the known prognostic factors, the integrated analysis of genetic variations and CNVs could contribute to prognostic stratification of patients with NDMM.

Immune Functions of Signaling Lymphocytic Activation Molecule Family Molecules in Multiple Myeloma

Simple Summary

Multiple myeloma (MM) is an incurable hematological malignancy characterized by an increase in abnormal plasma cells. Disease progression, drug resistance, and immunosuppression in MM are associated with immune-related molecules, such as immune checkpoint and co-stimulatory molecules, present in the tumor microenvironment. Novel agents targeting these cell-surface molecules are currently under development, including monoclonal antibodies, bispecific monoclonal antibodies, and chimera antigen receptor T-cell therapies. In this review, we focus on the signaling lymphocytic activation molecule family receptors and provide an overview of their biological functions and novel therapies in MM.

Abstract

The signaling lymphocytic activation molecule (SLAM) family receptors are expressed on various immune cells and malignant plasma cells in multiple myeloma (MM) patients. In immune cells, most SLAM family molecules bind to themselves to transmit co-stimulatory signals through the recruiting adaptor proteins SLAM-associated protein (SAP) or Ewing’s sarcoma-associated transcript 2 (EAT-2), which target immunoreceptor tyrosine-based switch motifs in the cytoplasmic regions of the receptors. Notably, SLAMF2, SLAMF3, SLAMF6, and SLAMF7 are strongly and constitutively expressed on MM cells that do not express the adaptor proteins SAP and EAT-2. This review summarizes recent studies on the expression and biological functions of SLAM family receptors during the malignant progression of MM and the resulting preclinical and clinical research involving four SLAM family receptors. A better understanding of the relationship between SLAM family receptors and MM disease progression may lead to the development of novel immunotherapies for relapse prevention.

Application of Single-Cell Sequencing to Immunotherapy

Cancer is a highly complex and heterogeneous disease and immunotherapy has shown promise as a therapeutic approach. The increased resolution afforded by single-cell analysis offers the hope of finding and characterizing previously underappreciated populations of cells that could prove useful in understanding cancer progression and treatment. Urologic and prostate cancers are inherently heterogeneous diseases, and the potential for single-cell analysis to help understand and develop immunotherapeutic approaches to treat these diseases is very exciting. In this review, we view cancer immunotherapy through a single-cell lens and discuss the state-of-the-art technologies that enable advances in this field.

Integrated Analysis of a Risk Score System Predicting Prognosis and a ceRNA Network for Differentially Expressed lncRNAs in Multiple Myeloma

Long non-coding RNAs (lncRNAs) are non-protein-coding RNAs longer than 200 nucleotides. Accumulating evidence demonstrates that lncRNA is a potential biomarker for cancer diagnosis and prognosis. However, there are no prognostic biomarkers and lncRNA models for multiple myeloma (MM). Hence, it is necessary to screen novel lncRNA that can potentially participate in the initiation and progression of MM and consequently construct a risk score system for the disease. Raw microarray datasets were obtained from the Gene Expression Omnibus website. Weighted gene co-expression network analysis and principal component analysis identified 12 lncRNAs of interest. Then, univariate, least absolute shrinkage and selection operator Cox regression and multivariate Cox hazard regression analysis identified two lncRNAs (LINC00996 and LINC00525) that were formulated to construct a risk score system to predict survival. Receiver operating characteristic analysis certificated the superior performance in predicting 3-year overall survival (area under the curve = 0.829). The similar prognostic values of the two-lncRNA signature were also observed in the tested The Cancer Genome Atlas dataset. Furthermore, two other lncRNAs (LINC00324 and LINC01128) were differentially expressed between CD138+ plasma cells from normal donors and MM patients and were verified to be associated with cancer stage in the Gene Expression Omnibus dataset. A lncRNA-mediated competing endogenous RNA network, including 2 lncRNAs, 12 mitochondrial RNAs, and 103 target messenger RNAs, was constructed. In conclusion, we developed a two-lncRNA expression signature to predict the prognosis of MM and constructed a key lncRNA-based competing endogenous RNA network in MM. These lncRNAs were associated with survival and are probably involved in the occurrence and progression of MM.

NCTD elicits proapoptotic and antiglycolytic effects on colorectal cancer cells via modulation of Fam46c expression and inhibition of ERK1/2 signaling

Colorectal cancer is a digestive tract malignancy and the third leading cause of cancer‑related mortality worldwide. Norcantharidin (NCTD), the demethylated form of cantharidin, has been reported to possess anticancer properties. Family‑with‑sequence‑similarity‑46c (Fam46c), a non‑canonical poly(A) polymerase, has been reported to be critical in NCTD‑mediated effects in numerous types of cancer, including hepatoma. In the current study, it was found that Fam46c expression was reduced in colorectal cancer tissues and cells. Treatment with NCTD was observed to significantly enhance apoptosis and inhibit glycolysis in colorectal cancer cells. In addition, Fam46c and cleaved caspase 3 expression levels were found to be increased in response to NCTD treatment, in contrast to tumor‑specific pyruvate kinase M2 and phosphorylated ERK expression, which was reduced. Importantly, overexpression of Fam46c exerted similar effects as NCTD treatment on the apoptosis and glycolysis of colorectal cancer cells, whereas Fam46c knockdown strongly attenuated the effect of NCTD. Moreover, epidermal growth factor, which acts as an agonist of ERK1/2 signaling, weakened the effects of NCTD on colorectal cancer cells. Taken together, the results indicated that NCTD promotes apoptosis and suppresses glycolysis in colorectal cancer cells by possibly targeting Fam46c and inhibiting ERK1/2 signaling, hence suggesting that Fam46c may act as a tumor suppressor in colorectal cancer. Thus, the present study identified a novel therapeutic target of NCTD in the clinical treatment of colorectal cancer.

PARP Inhibition Synergizes with Melphalan but Does not Reverse Resistance Completely

High-dose melphalan (MEL) and autologous stem cell transplantation (ASCT) is the standard of care in the treatment of multiple myeloma (MM). Resistance to MEL has been linked to increased DNA repair. Here we sought to identify whether inhibition of poly(ADP-ribose) polymerase (PARP) synergizes with MEL and can overcome resistance. We tested the synergistic cytotoxicity of 3 inhibitors of PARP (PARPi)-veliparib (VEL), olaparib (OLA), and niraparib (NIRA)-combined with MEL in RPMI8226 and U266 MM cell lines, as well as in their MEL resistance counterparts, RPMI8226-LR5 (LR5) and U266-LR6 (LR6). The addition of VEL, OLA, and NIRA to MEL reduced the half maximal inhibitory concentration (IC₅₀) in RPMI8226 cells from 27.8 µM to 23.1 µM, 22.5 µM, and 18.0 µM, respectively. Similarly, the IC₅₀ of MEL in U266 cells was decreased from 6.2 µM to 3.2 µM, 3.3 µM, and 3.0 µM, respectively. In LR5 and LR6 cells, PARPi did not reverse MEL resistance. We confirmed this in a NOD/SCID/gamma null xenograft mouse model with either MEL-sensitive (RPMI8226) or MEL-resistant (LR5) MM. Treatment with a MEL-VEL combination prolonged survival compared with MEL alone in RPMI8226 mice (107 days versus 67.5 days; P = .0009), but not in LR5 mice (41 versus 39 days; P = .09). We next tested whether 2 double-stranded DNA repair mechanisms, homologous recombination (HR) and nonhomologous end-joining (NHEJ), cause MEL resistance in LR5 and LR6 cells. In an HR assay, LR6 cells had a 4.5-fold greater HR capability than parent U226 cells (P = .05); however, LR5 cells had an equivalent HR ability as parent RPMI8226 cells. We hypothesized that NHEJ may be a mediator of MEL resistance in LR5 cells. Given that DNA-PK is integral to NHEJ and may be a therapeutic target, we treated LR5 cells with the DNA-PK inhibitor NU7026 in combination with MEL. Although NU7026 alone at 2.5 µM had no cytotoxicity, in combination it completely reversed resistance to MEL (MEL IC₅₀, 46.4 µM versus 14.4 µM). We examined the clinical implications of our findings in a dataset of 414 patients treated with tandem ASCT. High PARP1 expressers had lower survival compared with patients with low expression (median 42.7 months versus median not reached; P = .003). We hypothesized that combined expression of the HR gene BRCA1, the NHEJ gene PRKDC (DNA-PK), and PARP1 may predict survival and found that overexpression of 0 (n = 101), 1 or 2 (n = 287), or all 3 (n = 26) genes had a negative impact on median survival (undefined versus 57.8 months versus 14.8 months; P < .0001). Here we demonstrate that PARPi synergized with MEL, but that resistance (which may be due to HR and NHEJ pathways) is not completely reversed by PARPi. In addition, we observed that a 3-gene analysis may be tested to identify patients resistant or sensitive to high-dose MEL.

Synergistic Apoptotic Effects of Bortezomib and Methylstat on Multiple Myeloma Cells

BACKGROUND

In this study, we aimed to determine synergistic apoptotic and cytotoxic effects of methylstat and bortezomib on U266 and ARH77 multiple myeloma (MM) cells.

METHODS

Cytotoxic effects of the drugs were demonstrated by MTT cell proliferation assay while apoptotic effects were examined by loss of mitochondrial membrane potential (MMP) by JC-1 MMP detection kit, changes in caspase-3 enzyme activity and Annexin-V apoptosis assay by flow cytometry. Expression levels of apoptotic and antiapoptotic genes were examined by qRT-PCR.

RESULTS

Our results showed that combination of methylstat and bortezomib have synergistic antiproliferative effect on MM cells as compared to either agent alone. These results were also confirmed by showing synergistic apoptotic effects determined by increased loss of mitochondrial membrane potential and increased caspase-3 enzyme activity and relocation of phosphotidyleserine on the cell membrane by Annexin-V/PI double staining. Combination of bortezomib with methylstat arrested cells at the S phase of the cell cycle. Methylstat treatment caused upregulation of FASLG, NGFR, TNF, TNFRS10B and TNFRS1B apoptotic genes and downregulation of AKT1, AVEN, BAG1 BCL2L2 and RELA antiapoptotic genes in a dose and time dependent manner.

CONCLUSION

In conclusion, our data suggested that bortezomib in combination with methylstat decreased cell proliferation and induced apoptosis significantly in U266 and ARH77 cells. When supported with in vivo analyses, methylstat might be considered as a potential new agent for the treatment of MM.

Multiple Myeloma: Available Therapies and Causes of Drug Resistance

Multiple myeloma (MM) is the second most common blood cancer. Treatments for MM include corticosteroids, alkylating agents, anthracyclines, proteasome inhibitors, immunomodulatory drugs, histone deacetylase inhibitors and monoclonal antibodies. Survival outcomes have improved substantially due to the introduction of many of these drugs allied with their rational use. Nonetheless, MM patients successively relapse after one or more treatment regimens or become refractory, mostly due to drug resistance. This review focuses on the main drugs used in MM treatment and on causes of drug resistance, including cytogenetic, genetic and epigenetic alterations, abnormal drug transport and metabolism, dysregulation of apoptosis, autophagy activation and other intracellular signaling pathways, the presence of cancer stem cells, and the tumor microenvironment. Furthermore, we highlight the areas that need to be further clarified in an attempt to identify novel therapeutic targets to counteract drug resistance in MM patients.

TAZ functions as a tumor suppressor in multiple myeloma by downregulating MYC

Multiple myeloma (MM) is an incurable blood cancer that is often characterized by amplification and overexpression of the MYC oncogene. Despite efforts, direct targeting of MYC is not yet possible; therefore, alternative strategies to inhibit MYC activity are necessary. TAZ is a transcriptional coactivator downstream of the Hippo-signaling pathway that functions as an oncogene in many solid tumors. However, its role in hematological malignancies is largely unexplored. Here, we show that, in contrast to solid tumors, expression of TAZ is lower in hematological malignancies, and that high expression of TAZ correlates with better patient outcomes. We further show that TAZ is hypermethylated in MM patient samples and in a panel of MM cell lines. Genetic overexpression of TAZ or pharmacological upregulation of TAZ by treatment with the demethylating agent decitabine induces apoptosis. Importantly, TAZ-induced apoptosis is independent of canonical Hippo components LATS1 or the TEA-domain family of transcription factors. Instead, RNA-sequencing analysis revealed that overexpression of TAZ represses a MYC transcriptional program and we show that increased TAZ expression correlates with decreased MYC expression in both cell-line models and patient samples. Furthermore, promoter derepression of TAZ expression sensitizes MM cell lines through a reciprocal reduction in MYC expression using additional therapeutics such as bortezomib, trichostatin A, and panobinostat. Our findings uncover an unexpected role for TAZ in MM tumorigenesis and provide a compelling rationale for exploring the therapeutic potential of upregulating TAZ expression to restore sensitivity to specific therapeutics in MM.

Eruptive ulcerative follicular spicules heralding progression of smoldering multiple myeloma

Herein, we describe a patient with immunoglobulin G (IgG)-lambda smoldering multiple myeloma with translocation t(4:14) who developed widespread ulcerative horny-like spicules, heralding rapid progression to overt myeloma requiring aggressive chemotherapy and autologous stem cell transplantation. The serum abnormal immunoglobulin in the blood was cryoglobulin, which typically precipitates in the tissues at low temperatures causing inflammation and tissue damage. Histopathological changes, observed in lesions at different evolutionary stages, evidenced columns of horny-like eosinophilic homogeneous material, immunoreactive for IgG lambda, protruding from the dilated and/or distorted follicular openings or acrosyringia and small vessel thrombotic vasculopathy and vasculitis in concert with an inflammatory neutrophilic and lymphocytic reaction. Biochemical investigations on material from a spicule and ulcero-necrotic lesion revealed cryoprecipitates containing IgG-lambda with electrophoretic characteristics identical to those of the serum dysprotein. Our findings suggest that the formation of spicules and development of ulcerative lesions are a part of the same clinical spectrum where the cold-dependent precipitation of the immunogenic dysprotein, both in the skin vessels and hair follicle infundibula, play a major pathogenetic role. Whether this highly characteristic paraneoplastic dermatosis can identify patients with high-risk cytogenetic abnormalities and be incorporated into prognostic models, applicable early on in the course of myeloma, warrants further investigation.

Identification of the xenograft and its ascendant sphere-forming cell line as belonging to EBV-induced lymphoma, and characterization of the status of sphere-forming cells

BACKGROUND

We have characterized the human cell line arised from the Epstein-Barr virus (EBV) positive multiple myeloma aspirate subjected to the long-term cultivation. This cell line has acquired the ability to form free-floating spheres and to produce a xenograft upon transplantation into NOD/SCID mice.

METHODS

Cells from both in vitro culture and developed xenografts were investigated with a number of analytical approaches, including pathomorphological analysis, FISH analysis, and analysis of the surface antigens and of the VDJ locus rearrangement.

RESULTS

The obtained results, as well as the confirmed presence of EBV, testify that both biological systems are derived from B-cells, which, in turn, is a progeny of the EBV-transformed B-cellular clone that supplanted the primordial multiple myeloma cells. Next we assessed whether cells that (i) were constantly present in vitro in the investigated cell line, (ii) were among the sphere-forming cells, and (iii) were capable of internalizing a fluorescent TAMRA-labeled DNA probe (TAMRA+ cells) belonged to one of the three types of undifferentiated bone marrow cells of a multiple myeloma patient: CD34+ hematopoietic stem cells, CD90+ mesenchymal stem cells, and clonotypic multiple myeloma cell.

CONCLUSION

TAMRA+ cells were shown to constitute the fourth independent subpopulation of undifferentiated bone marrow cells of the multiple myeloma patient. We have demonstrated the formation of ectopic contacts between TAMRA+ cells and cells of other types in culture, in particular with CD90+ mesenchymal stem cells, followed by the transfer of some TAMRA+ cell material into the contacted cell.

Deciphering the chronology of copy number alterations in Multiple Myeloma

Multiple myeloma (MM) and its precursor condition MGUS are characterized by chromosomal aberrations. Here, we comprehensively characterize the order of occurrence of these complex genomic events underlying MM development using 500 MGUS, and MM samples. We identify hyperdiploid MM (HMM) and non-HMM as genomically distinct entities with different evolution of the copy number alterations. In HMM, gains of 9,15 or 19 are the first and clonal events observed as clonal even at MGUS stage. These events are thus early and may underlie initial transformation of normal plasma cells to MGUS cells. However, CNAs may not be adequate for progression to MM except in 15% of the patients in whom the complex subclonal deletion events are observed in MM but not MGUS. In NHMM, besides the driver translocations, clonal deletion of 13 and 1q gain are early events also observed in MGUS. We combined this information to propose a timeline for copy number alteration.

Cytogenetic Abnormalities in Multiple Myeloma Patients at a Tertiary Healthcare Center in India

Objective:

Multiple myeloma (MM) is a clinically and genetically heterogeneous plasma cell neoplasm. The prognosis of MM patients is dependent on several factors including the patient’s age, the stage of disease and genetic alterations. This study aimed to determine the frequency of common chromosomal abnormalities and their significance in MM patients referred to a tertiary healthcare center in India.

Methods:

Fluorescence in situ hybridization on interphase nuclei from bone marrow cells using seven MM-specific probes for recurrent aberrations was performed in a total of 215 newly diagnosed patients.

Results:

Chromosomal abnormalities were detected in 161 (74.9%) MM patients in this study. The most frequent aberration was trisomy(ies) involving only gain of chromosomes in 48 (22.3%) cases. A translocation involving the IGH gene alone or accompanied by trisomy(ies) or by monosomy 13/13q deletion or by both was registered in 80 (37.2%) patients. Atypical patterns such as a deletion of the IGH variable segment (IGHv) on the derivative chromosome 14 or on the native (normal) chromosome 14, biallelic deletion of IGHv, deletion of the IGH constant segment on the rearranged chromosome14 and extra fusions were noticed in 21 (9.8%) patients with an IGH rearrangement. Monosomy 13/deletion 13q was identified singly or as part of a complex karyotype in 74 patients (34.4%). Clonal heterogeneity and additional abnormalities including TP53 deletion and monosomies of chromosomes 4, 9, 14 and 16 were recorded in 18.6% and 16.3% of patients respectively. Patients with abnormalities exhibited plasmacytosis, reduced hemoglobin value and high level of ß2-microglobulin.

Conclusions:

A lower median age and a low frequency of IGH translocations particularly t(11;14) and chromosome 13 abnormalities suggest ethnic diversity. Further investigations on genetic alterations including IGH deletions will contribute to improved insights into the biology of myeloma disease, risk stratification and patient management.

An unusual presentation of multiple myeloma

The authors report a case of a 58-year-old woman, ex-smoker, who was referred to the respiratory clinic with a presumed unresolving airspace shadowing in the right lung. Further evaluation of the shadowing with a CT thorax revealed rib lesions, a pancreatic lesion and multiple liver lesions, making the diagnosis of metastatic pancreatic carcinoma most likely. However, further blood investigations and imaging eventually revealed the cause for the shadowing to be multiple myeloma, since the unresolving shadowing was actually a rib lesion.

Pharmacological Properties, Molecular Mechanisms, and Pharmaceutical Development of Asiatic Acid: A Pentacyclic Triterpenoid of Therapeutic Promise

Asiatic acid (AA) is a naturally occurring aglycone of ursane type pentacyclic triterpenoids. It is abundantly present in many edible and medicinal plants including Centella asiatica that is a reputed herb in many traditional medicine formulations for wound healing and neuropsychiatric diseases. AA possesses numerous pharmacological activities such as antioxidant and anti-inflammatory and regulates apoptosis that attributes its therapeutic effects in numerous diseases. AA showed potent antihypertensive, nootropic, neuroprotective, cardioprotective, antimicrobial, and antitumor activities in preclinical studies. In various in vitro and in vivo studies, AA found to affect many enzymes, receptors, growth factors, transcription factors, apoptotic proteins, and cell signaling cascades. This review aims to represent the available reports on therapeutic potential and the underlying pharmacological and molecular mechanisms of AA. The review also also discusses the challenges and prospects on the pharmaceutical development of AA such as pharmacokinetics, physicochemical properties, analysis and structural modifications, and drug delivery. AA showed favorable pharmacokinetics and found bioavailable following oral or interaperitoneal administration. The studies demonstrate the polypharmacological properties, therapeutic potential and molecular mechanisms of AA in numerous diseases. Taken together the evidences from available studies, AA appears one of the important multitargeted polypharmacological agents of natural origin for further pharmaceutical development and clinical application. Provided the favorable pharmacokinetics, safety, and efficacy, AA can be a promising agent or adjuvant along with currently used modern medicines with a pharmacological basis of its use in therapeutics.

Prognostic impact of hyperdiploidy in multiple myeloma patients with high-risk cytogenetics: a pilot study in China

PURPOSE

Multiple myeloma is genetically heterogeneous with varied clinical outcomes, primarily due to the coexistence of diverse numerical and structural cytogenetic abnormalities. The prognostic impact of hyperdiploidy in myeloma patients with high-risk cytogenetics remains controversial in Western studies and is unknown in China.

METHODS

We examined the cytogenetic features of hyperdiploidy in 201 Chinese patients with newly diagnosed myeloma using magnetic-activated cell sorting and interphase fluorescence in situ hybridization and analyzed the effect of hyperdiploidy on the prognosis of patients with high-risk cytogenetics.

RESULTS

Hyperdiploidy was detected in 50.7% (102/201) of the examined patients, and the incidence of hyperdiploidy coexisting with high-risk cytogenetics [del(17p13), +1q21 and adverse t(14q32)] was 33.8% (68/201). Survival analysis showed that the median progression-free survival (PFS) and 2-year overall survival (OS) of patients were better for hyperdiploidy than those for non-hyperdiploidy (43 vs. 20 months, P = 0.01; 86.8% vs. 70.5%, P = 0.04) and for standard-risk cytogenetics than those for high-risk cytogenetics (not reached vs. 23 months, P = 0.0001; 87.6% vs. 74.4%, P = 0.01). Strikingly, the high-risk cytogenetics patients with hyperdiploidy showed a better median PFS than those without hyperdiploidy (34 vs. 15 months, P = 0.01); however, compared to standard-risk cytogenetics patients, the median PFS and 2-year OS were poorer (34 months vs. not reached, P = 0.02; 78.8% vs. 87.6%, P = 0.05). The independent predictors of PFS were non-hyperdiploidy, high-risk cytogenetics, and bone marrow plasma cells ≥ 30%, with hazard ratios of 2.01 (95% CI 1.25-3.25), 2.56 (95% CI 1.38-4.74), and 1.81 (95% CI 1.08-3.05), respectively, and those for OS were non-hyperdiploidy and serum lactate dehydrogenase ≥ 250 U/L, with hazard ratios of 2.53 (95% CI 1.24-5.46) and 3.53 (95% CI 1.50-6.96), respectively.

CONCLUSIONS

These results suggest that the coexistence of hyperdiploidy may ameliorate the adverse prognosis of multiple myeloma patients with high-risk cytogenetics. High-risk cytogenetics patients without hyperdiploidy showed the worst prognosis.

The insulin-like growth factor system in multiple myeloma: diagnostic and therapeutic potential

Multiple myeloma (MM) is a highly heterogeneous plasma cell malignancy. The MM cells reside in the bone marrow (BM), where reciprocal interactions with the BM niche foster MM cell survival, proliferation, and drug resistance. As in most cancers, the insulin-like growth factor (IGF) system has been demonstrated to play a key role in the pathogenesis of MM. The IGF system consists of IGF ligands, IGF receptors, IGF binding proteins (IGFBPs), and IGFBP proteases and contributes not only to the survival, proliferation, and homing of MM cells, but also MM-associated angiogenesis and osteolysis. Furthermore, increased IGF-I receptor (IGF-IR) expression on MM cells correlates with a poor prognosis in MM patients. Despite the prominent role of the IGF system in MM, strategies targeting the IGF-IR using blocking antibodies or small molecule inhibitors have failed to translate into the clinic. However, increasing preclinical evidence indicates that IGF-I is also involved in the development of drug resistance against current standard-of-care agents against MM, including proteasome inhibitors, immunomodulatory agents, and corticoids. IGF-IR targeting has been able to overcome or revert this drug resistance in animal models, enhancing the efficacy of standard-of-care agents. This finding has generated renewed interest in the therapeutic potential of IGF-I targeting in MM. The present review provides an update of the impact of the different IGF system components in MM and discusses the diagnostic and therapeutic potentials.

The Utilization of Karyotyping, iFISH, and MLPA for the Detection of Recurrence Genetic Aberrations in Multiple Myeloma

Multiple myeloma (MM) is a hematological malignancy characterized by abnormal accumulation of clonal plasma cells in the bone marrow. Recently, multiplex ligation-dependent probe amplification (MLPA) has emerged as an effective and robust method for detection of common genetic alterations in MM patients. Here, we aimed to confirm MLPA utility for this purpose and furthermore to test the feasibility of a combination of karyotyping, interphase fluorescence in situ hybridization (iFISH) and MLPA methods for diagnosis, prognostic assessment and risk stratification of MM. Thirty-five genomic DNA samples isolated from CD138-enriched plasma cells from bone marrow of MM patients were analyzed using the MLPA method. We found that amp (1q) was the most frequent genetic alteration (48.6%) in the tested samples, followed by del (1p) and del (13q) (34.3%). Moreover, concordant results between sensitivity and specificity of iFISH and MLPA for the detection of del (13q) (p-value >0.05) and del (17p) (p-value >0.05) were obtained. In summary, we could provide evidence of MLPA assay utility for the detection of common genetic alterations in MM. The combination of karyotyping, iFISH, and MLPA proved very helpful for clinical risk stratification.

The non-canonical poly(A) polymerase FAM46C acts as an onco-suppressor in multiple myeloma

FAM46C is one of the most frequently mutated genes in multiple myeloma. Here, using a combination of in vitro and in vivo approaches, we demonstrate that FAM46C encodes an active non-canonical poly(A) polymerase which enhances mRNA stability and gene expression. Reintroduction of active FAM46C into multiple myeloma cell lines, but not its catalytically-inactive mutant, leads to broad polyadenylation and stabilization of mRNAs strongly enriched with those encoding endoplasmic reticulum-targeted proteins and induces cell death. Moreover, silencing of FAM46C in multiple myeloma cells expressing WT protein enhance cell proliferation. Finally, using a FAM46C-FLAG knock-in mouse strain, we show that the FAM46C protein is strongly induced during activation of primary splenocytes and that B lymphocytes isolated from newly generated FAM46C KO mice proliferate faster than those isolated from their WT littermates. Concluding, our data clearly indicate that FAM46C works as an onco-suppressor, with the specificity for B-lymphocyte lineage from which multiple myeloma originates.

FAM46C is one of the most frequently mutated genes in multiple myeloma (MM), but its molecular function remains unknown. Here the authors show that FAM46C is a poly(A) polymerase and that loss of function of FAM46C drives multiple myeloma through the destabilisation of ER response transcripts.

Epigenetic modifications in multiple myeloma: recent advances on the role of DNA and histone methylation

INTRODUCTION

Multiple Myeloma (MM) is a clonal late B-cell disorder accounting for about 13% of hematological cancers and 1% of all neoplastic diseases. Recent studies on the molecular pathogenesis and biology of MM have highlighted a complex epigenomic landscape contributing to MM onset, prognosis and high individual variability. Areas covered: We describe here the current knowledge on epigenetic events characterizing MM initiation and progression, focusing on the role of DNA and histone methylation and on the most promising epi-therapeutic approaches targeting the methylation pathway. Expert opinion: Data published so far indicate that alterations of the epigenetic framework, which include aberrant global or gene/non-coding RNA specific methylation profiles, feature prominently in the pathobiology of MM. Indeed, the aberrant expression of components of the epigenetic machinery as well as the reversibility of the epigenetic marks make this pathway druggable, providing the basis for the design of epigenetic therapies against this still fatal malignancy.

Additional-structural-chromosomal aberrations are associated with inferior clinical outcome in patients with hyperdiploid multiple myeloma: a single-institution experience

Multiple myeloma is cytogenetically heterogeneous and a hyperdiploid karyotype is considered currently to have standard risk. In this study, we investigated the clinical impact of additional-structural-chromosomal aberrations assessed by chromosome analysis in 284 patients with a hyperdiploid karyotype that were subdivided into four groups based on the complexity of additional-structural-chromosomal aberrations: group 1, no additional-structural-chromosomal aberrations (n=35); group 2, one additional-structural-chromosomal aberration (n=46); group 3, two additional-structural-chromosomal aberrations (n=39); group 4, ≥three additional-structural-chromosomal aberrations (n=164). Clinicopathological data among these groups showed no differences, except patients in group 1 had higher hemoglobin (P=0.031) and albumin (P=0.045) levels. The median follow-up was 55 months (range, 3-221). The median overall survival of patients in groups 1-4 was negatively correlated with the number of the additional-structural-chromosomal aberrations: 98, 76, 61, and 48 months, respectively (P<0.0001). In group 4, CKS1B gain, RB1, or TP53 deletions had no additional impact on overall survival; however, trisomy 3 or 15 conferred a much better overall survival, and monosomy 13 and 14 predicted a worse outcome. In addition, the overall survival of patients in groups 3 and 4 was similar to a subset of high-risk multiple myeloma cases (n=21) (P=0.387). About 192 (67.6%) patients who received stem cell transplantation did not show improved overall survival compared with non-stem cell transplantation patients (n=92; P=0.142) overall; however, they did show significantly improved overall survival in patients with refractory disease in group 4 (P=0.0084). Multivariate analysis showed that two or more additional-structural-chromosomal aberrations (P<0.0001), stages (P=0.02 and P=0.002) and relapsed disease (P=0.009) negatively impacted the overall survival. We conclude that hyperdiploid karyotypes in multiple myeloma are associated with additional-structural-chromosomal aberrations and a greater number of additional-structural-chromosomal aberrations predicts poorer clinical outcome. A hyperdiploid karyotype with ≥2 additional-structural-chromosomal aberrations at chromosomal level should be considered an independent high-risk factor.

Proteome alterations associated with transformation of multiple myeloma to secondary plasma cell leukemia

Plasma cell leukemia is a rare and aggressive plasma cell neoplasm that may either originate de novo (primary PCL) or by leukemic transformation of multiple myeloma (MM) to secondary PCL (sPCL). The prognosis of sPCL is very poor, and currently no standard treatment is available due to lack of prospective clinical studies. In an attempt to elucidate factors contributing to transformation, we have performed super-SILAC quantitative proteome profiling of malignant plasma cells collected from the same patient at both the MM and sPCL stages of the disease. 795 proteins were found to be differentially expressed in the MM and sPCL samples. Gene ontology analysis indicated a metabolic shift towards aerobic glycolysis in sPCL as well as marked down-regulation of enzymes involved in glycan synthesis, potentially mediating altered glycosylation of surface receptors. There was no significant change in overall genomic 5-methylcytosine or 5-hydroxymethylcytosine at the two stages, indicating that epigenetic dysregulation was not a major driver of transformation to sPCL. The present study constitutes the first attempt to provide a comprehensive map of the altered protein expression profile accompanying transformation of MM to sPCL in a single patient, identifying several candidate proteins that can be targeted by currently available small molecule drugs. Our dataset furthermore constitutes a reference dataset for further proteomic analysis of sPCL transformation.

Cytogenetic Study and Analysis of Protein Expression in Plasma Cell Myeloma with t(11;14)(q13;q32): Absence of BCL6 and SOX11, and Infrequent Expression of CD20 and PAX5

The t(11;14)(q13;q32) translocation is the most common chromosomal translocation in plasma cell myeloma (PCM), but the cytogenetic and immunophenotypic features of PCM with t(11;14)(q13;q32) remain to be fully elucidated. To address the issue, we retrospectively analyzed 21 newly diagnosed PCM patients with the t(11;14)(q13;q32) translocation in our institute. CD20 is a B-cell-specific transmembrane protein that is the topic of much focus as a potential target in immunotherapy. We observed a low incidence of CD20 expression (2 of 21 patients, 11%), although the expression of CD20 was previously reported to be associated with t(11;14)(q13;q32). PAX5 is an essential transcriptional factor involved in B-cell development and commitment, and is down-regulated upon plasma cell differentiation. We observed one patient (6%) with expression of PAX5. The expression of CD19, CD56, and CD138 was detected in one (0.7%), nine (60%), and 13 patients (87%), respectively. Cyclin D1, CD38, and BCL2 were detected in all patients; on the other hand, neither BCL6 nor SOX11 was detected in any of the evaluated patients. Abnormalities of chromosome 13 were detected in six patients (38%), but deletion of TP53 was not observed in any of the evaluated patients. Our results suggest the absence of BCL6 and SOX11 expression, and infrequent expression of CD20, PAX5, and CD56 in PCM with t(11;14)(q13;q32), in contrast to the findings of earlier reports.