Mutational Spectrum, Copy Number Changes, and Outcome: Results of a Sequencing Study of Patients With Newly Diagnosed Myeloma

A Tangle of Genomic Aberrations Drives Multiple Myeloma and Correlates with Clinical Aggressiveness of the Disease: A Comprehensive Review from a Biological Perspective to Clinical Trial Results

Multiple myeloma (MM) is a genetically heterogeneous disease, in which the process of tumorigenesis begins and progresses through the appearance and accumulation of a tangle of genomic aberrations. Several are the mechanisms of DNA damage in MM, varying from single nucleotide substitutions to complex genomic events. The timing of appearance of aberrations is well studied due to the natural history of the disease, that usually progress from pre-malignant to malignant phase. Different kinds of aberrations carry different prognostic significance and have been associated with drug resistance in some studies. Certain genetic events are well known to be associated with prognosis and are incorporated in risk evaluation in MM at diagnosis in the revised International Scoring System (R-ISS). The significance of some other aberrations needs to be further explained. Since now, few phase 3 randomized trials included analysis on patient's outcomes according to genetic risk, and further studies are needed to obtain useful data to stratify the choice of initial and subsequent treatment in MM.

The prognostic value of additional copies of 1q21 in multiple myeloma depends on the primary genetic event

Hyperdiploidy (HRD) and specific immunoglobulin heavy locus (IGH) translocations are primary chromosomal abnormalities (CA) in multiple myeloma (MM). In this retrospective study of 794 MM patients we aimed to investigate clinical features and common CA including gain(1q) in separate subgroups defined by primary CA. In the entire group, we confirmed that gain(1q) was associated with short time to next treatment and adverse overall survival (OS). The impact was worse for four or more copies of 1q21 as compared to three copies. However, in a subgroup of patients with clonal gain(11q) and without known primary IGH translocations (CG11q), already three copies of 1q21 were associated with a poor outcome; in the absence of gain(1q), patients in this subgroup had a remarkably long median OS of more than nine years. These cases were associated with HRD, coexpression of CD56 and CD117, male gender, and IgG subtype. In non‐CG11q patients, four or more copies of 1q21 (but not three copies) had a significant adverse impact on outcome. Several associations with CA and clinical findings were observed for the defined subgroups. As an example, we found a predominance of early tetraploidy, plasma cell leukemia, and female gender in the t(14;16) subgroup. Our results underscore the importance of subgrouping in MM.

The clinical impact of hepatitis C virus infection in Egyptian multiple myeloma patients

BACKGROUND

Multiple myeloma (MM) is a human B cell neoplasia characterized by the clonal proliferation of malignant plasma cells in the bone marrow. Worldwide, hepatitis C virus (HCV) infection is a public health problem. For MM patients, the clinical impact of preexisting HCV infection is still unclear. We aim to assess the clinical characteristics and the prevalence of the HCV infection in Egyptian MM patients. This observational study included 81 MM patients. HCV antibody assay was performed, and positive cases were confirmed using a reverse transcription-quantitative PCR (RT-PCR) method.

RESULTS

Fifteen (18.5%) patients were anti-HCV antibody positive. Only 6/15 (7.4%) patients were HCV RNA positive by RT-PCR. Liver affection in the form of hyperbilirubinemia with grade 4 adverse events was significantly higher in the anti-HCV positive/HCV RNA positive group versus anti HCV negative group (16.7% vs. 1.5%, p value = 0.005). The median HCV-RNA before the initiation of chemotherapy was 2.5 log IU/ml with mean ± SD = 4.25 ± 1.6 with no HCV reactivation. In the univariate and multivariate analysis, HCV infection was not an independent factor related to DFS. Low hemoglobin level < 10 g/dL (HR 0.59, 95% CI, 0.36-0.97, p value = 0.037) and abnormal serum total bilirubin level (HR 1.9, 95% CI 1.03-3.5, p value = 0.039) influenced DFS in the univariate analysis. However, in the multivariate analysis, serum calcium level greater than 12 mg/dL (HR 7.04, 95% CI 1.12-44.45, p value = 0.038) and abnormal serum total bilirubin level (HR 10.9, 95% CI 2.92-41.02, p value = < 0.001) remained statistically significant worse prognostic factors.

CONCLUSION

In conclusion, our study revealed the prevalence of HCV infection in Egyptian MM patients. Serologic tests at diagnosis are necessary to identify these patients, and confirmation of positive cases by molecular techniques should be mandatory, with regular follow-up for liver dysfunction. Finally, further larger studies explaining the molecular mechanisms linking HCV and the MM pathogenesis are warranted.

Risk and Response-Adapted Treatment in Multiple Myeloma

Simple Summary

Therapeutic strategies in multiple myeloma have been adapted only to age and comorbidities for a long time. Given the currently available therapeutic and technologic arsenal, the time may have come to refine this adaptation. First, high-risk patients should benefit from the most intensive and efficient combinations from diagnosis. Here, we review these different strategies and how to define and identify high-risk myeloma patients in current clinical practice. In addition, the advent of technologies detecting minimal residual disease gives us this opportunity to define the quality of response to treatment with an unpreceded sensitivity and adapt treatment accordingly. Finally, even if molecular targeting is still nascent in myeloma, some molecular features are interesting to detect at relapse to determine optimal salvage treatments.

Abstract

Myeloma therapeutic strategies have been adapted to patients’ age and comorbidities for a long time. However, although cytogenetics and clinical presentations (plasmablastic cytology; extramedullary disease) are major prognostic factors, until recently, all patients received the same treatment whatever their initial risk. No strong evidence allows us to use a personalized treatment according to one cytogenetic abnormality in newly diagnosed myeloma. Retrospective studies showed a benefit of a double autologous transplant in high-risk cytogenetics according to the International Myeloma Working Group definition (t(4;14), t(14;16) or del(17p)). Moreover, this definition has to be updated since other independent abnormalities, namely gain 1q, del(1p32), and trisomies 5 or 21, as well as TP53 mutations, are also prognostic. Another very strong predictive tool is the response to treatment assessed by the evaluation of minimal residual disease (MRD). We are convinced that the time has come to use it to adapt the strategy to a dynamic risk. Many trials are ongoing to answer many questions: when and how should we adapt the therapy, its intensity and duration. Nevertheless, we also have to take into account the clinical outcome for one patient, especially adverse events affecting his or her quality of life and his or her preferences for continuous/fixed duration treatment.

Shaping the Treatment Paradigm Based on the Current Understanding of the Pathobiology of Multiple Myeloma: An Overview

Multiple myeloma is an incurable malignancy which despite progressive improvements in overall survival over the last decade remains characterised by recurrent relapse with progressively shorter duration of response and treatment-free intervals with each subsequent treatment. Efforts to unravel the complex and heterogeneous genomic alterations, the marked dysregulation of the immune system and the multifarious interplay between malignant plasma cells and those of the tumour microenvironment have not only led to improved understanding of myelomagenesis and disease progression but have facilitated the rapid development of novel therapeutics including immunotherapies and small molecules bringing us a step closer to therapies that no doubt will extend survival. Novel therapeutic combinations both in the upfront and relapsed setting as well as novel methods to assess response and guide management are rapidly transforming the management of myeloma.

Emerging agents and regimens for multiple myeloma

The outcomes of multiple myeloma (MM) have been improved significantly with the therapies incorporating proteasome inhibitors (PI), immunomodulatory drugs, monoclonal antibodies (MoAb) and stem cell transplantation. However, relapsed and refractory MM (RRMM) remains a major challenge. Novel agents and regimens are under active clinical development. These include new PIs such as ixazomib, marizomib, and oprozomib; new MoAbs such as isatuximab and MOR202; novel epigenetic agent ricolinostat and novel cytokines such as siltuximab. Recently, the first XPO-1 inhibitor, selinexor, was approved for RRMM. BCMA-targeted BiTE, antibody-drug conjugates and CAR-T cells have the potential to revolutionize the therapy for RRMM. In this review, we summarized the latest clinical development of these novel agents and regimens.

Intermittent schedules of the oral RAF-MEK inhibitor CH5126766/VS-6766 in patients with RAS/RAF-mutant solid tumours and multiple myeloma: a single-centre, open-label, phase 1 dose-escalation and basket dose-expansion study

BACKGROUND

CH5126766 (also known as VS-6766, and previously named RO5126766), a novel MEK-pan-RAF inhibitor, has shown antitumour activity across various solid tumours; however, its initial development was limited by toxicity. We aimed to investigate the safety and toxicity profile of intermittent dosing schedules of CH5126766, and the antitumour activity of this drug in patients with solid tumours and multiple myeloma harbouring RAS-RAF-MEK pathway mutations.

METHODS

We did a single-centre, open-label, phase 1 dose-escalation and basket dose-expansion study at the Royal Marsden National Health Service Foundation Trust (London, UK). Patients were eligible for the study if they were aged 18 years or older, had cancers that were refractory to conventional treatment or for which no conventional therapy existed, and if they had a WHO performance status score of 0 or 1. For the dose-escalation phase, eligible patients had histologically or cytologically confirmed advanced or metastatic solid tumours. For the basket dose-expansion phase, eligible patients had advanced or metastatic solid tumours or multiple myeloma harbouring RAS-RAF-MEK pathway mutations. During the dose-escalation phase, we evaluated three intermittent oral schedules (28-day cycles) in patients with solid tumours: (1) 4·0 mg or 3·2 mg CH5126766 three times per week; (2) 4·0 mg CH5126766 twice per week; and (3) toxicity-guided dose interruption schedule, in which treatment at the recommended phase 2 dose (4·0 mg CH5126766 twice per week) was de-escalated to 3 weeks on followed by 1 week off if patients had prespecified toxic effects (grade 2 or worse diarrhoea, rash, or creatinine phosphokinase elevation). In the basket dose-expansion phase, we evaluated antitumour activity at the recommended phase 2 dose, determined from the dose-escalation phase, in biomarker-selected patients. The primary endpoints were the recommended phase 2 dose at which no more than one out of six patients had a treatment-related dose-limiting toxicity, and the safety and toxicity profile of each dosing schedule. The key secondary endpoint was investigator-assessed response rate in the dose-expansion phase. Patients who received at least one dose of the study drug were evaluable for safety and patients who received one cycle of the study drug and underwent baseline disease assessment were evaluable for response. This trial is registered with ClinicalTrials.gov, NCT02407509.

FINDINGS

Between June 5, 2013, and Jan 10, 2019, 58 eligible patients were enrolled to the study: 29 patients with solid tumours were included in the dose-escalation cohort and 29 patients with solid tumours or multiple myeloma were included in the basket dose-expansion cohort (12 non-small-cell lung cancer, five gynaecological malignancy, four colorectal cancer, one melanoma, and seven multiple myeloma). Median follow-up at the time of data cutoff was 2·3 months (IQR 1·6-3·5). Dose-limiting toxicities included grade 3 bilateral retinal pigment epithelial detachment in one patient who received 4·0 mg CH5126766 three times per week, and grade 3 rash (in two patients) and grade 3 creatinine phosphokinase elevation (in one patient) in those who received 3·2 mg CH5126766 three times per week. 4·0 mg CH5126766 twice per week (on Monday and Thursday or Tuesday and Friday) was established as the recommended phase 2 dose. The most common grade 3-4 treatment-related adverse events were rash (11 [19%] patients), creatinine phosphokinase elevation (six [11%]), hypoalbuminaemia (six [11%]), and fatigue (four [7%]). Five (9%) patients had serious treatment-related adverse events. There were no treatment-related deaths. Eight (14%) of 57 patients died during the trial due to disease progression. Seven (27% [95% CI 11·6-47·8]) of 26 response-evaluable patients in the basket expansion achieved objective responses.

INTERPRETATION

To our knowledge, this is the first study to show that highly intermittent schedules of a RAF-MEK inhibitor has antitumour activity across various cancers with RAF-RAS-MEK pathway mutations, and that this inhibitor is tolerable. CH5126766 used as a monotherapy and in combination regimens warrants further evaluation.

FUNDING

Chugai Pharmaceutical.

A Rare CD4-CD8+ Adult T-Cell Leukemia/Lymphoma with Unique Molecular Mutations: A Case Report with Literature Review

Adult T-cell leukemia/lymphoma (ATLL) is a mature T-cell neoplasm caused by infection of the human T-cell lymphotropic virus type 1 (HTLV-1). Most ATLL cases are CD4-positive and CD8-negative. Though rare, there are a few dual negative (CD4-CD8-), dual positive (CD4+CD8+), and CD4-CD8+ cases reported in literature. ATLL is associated with HTLV-1 infection, but HTLV-1 alone cannot cause the malignant transformation of infected T cells. Additional genetic and/or epigenetic events are required for the development of the disease. Here, we report an unusual CD4-CD8+ATLL in a 76-year-old male with a unique molecular genetic profile. Molecular studies revealed alterations in 10 genes. Three of them are predicted to be pathogenic by the computational models, including the frameshift change in ZFHX4 and missense mutations in RHOA and POT1. The specific mutations of POT1 (c.281A > G; p.Q94R), RHOA (c.47G > A; p.C16Y), and ZFHX4 (c.2871delC; p.F958Sfs ∗ 31) have never been previously reported in ATLL to the best of our knowledge. The clinical significance of other genetic alterations is unknown. Further research is warranted to correlate this patient's molecular findings with other ATLL cases. Correlation specifically with other cases of CD8+ ATLL could prove to be useful in understanding the pathogenesis of this rare variant of an already rare form of leukemia/lymphoma.

Targeting the Mutational Landscape of Bystander Cells: Drug-Promoted Blood Cancer From High-Prevalence Pre-neoplasias in Patients on BRAF Inhibitors

Drug-promoted cancers are increasingly recognized as a serious clinical problem in patients receiving BRAF inhibitory treatment. Here we report on a patient with BRAF mutant hairy cell leukemia and monoclonal B-cell lymphocytosis (MBL), who responded durably to BRAF/MEK inhibitors (BRAFi/MEKi) but experienced transformation of a RAS mutant MBL to chronic lymphocytic leukemia (CLL) with accelerated nodal progression. Hypothesizing that BRAFi triggered excessive MEK-ERK signaling in the MBL/CLL clone via the CRAF/RAS complex as previously described for BRAFi-induced cancers, BRAFi was discontinued inducing a rapid remission of the CLL on MEKi alone. Liquid biopsy monitoring showed a continuous increase of the MBL/CLL clone from the start of BRAFi/MEKi treatment followed by a rapid decline upon BRAFi withdrawal. Next-generation sequencing of a cohort of patients with MBL and monoclonal gammopathy of unclear significance (MGUS) revealed that almost one third of these cases harbored RAS mutations. In view of the population frequency of lymphatic pre-malignant conditions and the prevalence of RAS mutations in such cases, vigilant surveillance remains critical in patients treated with BRAF inhibitors.

KRAS, NRAS, and BRAF mutations in plasma cell myeloma at a single Korean institute

Background

Plasma cell myeloma (PCM) is a genetically heterogeneous disease. The genetic spectrum of PCM has been expanded to mutations such as KRAS, NRAS, and BRAF genes in the RAS-RAF-MAPK pathway. In this study, we have evaluated the frequency of these mutations and their significance, including baseline characteristics and clinical outcomes.

Methods

We explored 50 patients who were newly diagnosed with PCM between 2009 and 2012 at a single Korean institute. Clinical and laboratory parameters were gathered through careful review of medical records. Mutation analysis was carried out using DNA from the bone marrow at the time of diagnosis. Pyrosequencing was performed to detect KRAS G12V, KRAS G13D, and NRAS G61R. BRAF V600E was analyzed by allele-specific real-time PCR. Comparison of clinical and laboratory parameters was carried out according to those mutations.

Results

We identified 14 patients (28%) with activating mutations in the RAS-RAF-MAPK pathway (RAS/RAF mutations) KRAS (N=3), NRAS (N=4), BRAF (N=7), and both KRAS and BRAF (N=1). RAS/RAF mutations were more frequently observed in patients with complex karyotypes and showed poorer progression free survival (PFS). Specifically, the BRAF V600E mutation had a significantly negative impact on median PFS.

Conclusion

We first showed the frequency of RAS/RAF mutations in Korean patients with PCM. Screening of these mutations could be considered as a routine clinical test at the time of diagnosis and follow-up due to their influence on clinical outcome, as well as its potential as a therapeutic target.

The long non-coding RNA CRNDE regulates growth of multiple myeloma cells via an effect on IL6 signalling

Multiple myeloma (MM) is a currently incurable malignancy of antibody-secreting plasma cells. Long non-coding RNAs (lncRNAs) have been recognised as an important class of regulatory molecules which are increasingly implicated in tumorigenesis. While recent studies have demonstrated changes in expression of lncRNAs in MM, the functional significance and molecular pathways downstream of these changes remain poorly characterised. In this study, we have performed CRISPR-mediated deletion of the locus encoding the lncRNA Colorectal Neoplasia Differentially Expressed (CRNDE), a known oncogenic lncRNA that is overexpressed in plasma cells of MM patients and is a marker of poor prognosis. We found that CRISPR-mediated deletion of the CRNDE locus in MM cells decreases proliferation and adhesion properties, increases sensitivity to Dexamethasone and reduces tumour growth in an in vivo xenograft model. Transcriptomic profiling in CRNDE-deleted MM cells demonstrated that CRNDE activates expression of a number of genes previously implicated in the aetiology of MM, including IL6R. We further demonstrate that deletion of the CRNDE locus diminishes IL6 signalling and proliferative responses in MM cells. Altogether this study reveals the IL6 signalling pathway as a novel mechanism by which CRNDE impacts upon MM cell growth and disease progression.

Integrated phosphoproteomics and transcriptional classifiers reveal hidden RAS signaling dynamics in multiple myeloma

A major driver of multiple myeloma (MM) is thought to be aberrant signaling, yet no kinase inhibitors have proven successful in the clinic. Here, we employed an integrated, systems approach combining phosphoproteomic and transcriptome analysis to dissect cellular signaling in MM to inform precision medicine strategies. Unbiased phosphoproteomics initially revealed differential activation of kinases across MM cell lines and that sensitivity to mammalian target of rapamycin (mTOR) inhibition may be particularly dependent on mTOR kinase baseline activity. We further noted differential activity of immediate downstream effectors of Ras as a function of cell line genotype. We extended these observations to patient transcriptome data in the Multiple Myeloma Research Foundation CoMMpass study. A machine-learning-based classifier identified surprisingly divergent transcriptional outputs between NRAS- and KRAS-mutated tumors. Genetic dependency and gene expression analysis revealed mutated Ras as a selective vulnerability, but not other MAPK pathway genes. Transcriptional analysis further suggested that aberrant MAPK pathway activation is only present in a fraction of RAS-mutated vs wild-type RAS patients. These high-MAPK patients, enriched for NRAS Q61 mutations, have inferior outcomes, whereas RAS mutations overall carry no survival impact. We further developed an interactive software tool to relate pharmacologic and genetic kinase dependencies in myeloma. Collectively, these predictive models identify vulnerable signaling signatures and highlight surprising differences in functional signaling patterns between NRAS and KRAS mutants invisible to the genomic landscape. These results will lead to improved stratification of MM patients in precision medicine trials while also revealing unexplored modes of Ras biology in MM.

The clonal evolution during long-term clinical course of multiple myeloma

Somatic gene mutations related to acceleration disease and clonal evolution in multiple myeloma strongly influence severe clinical outcomes. In this study, we traced the transition of somatic mutations during the clinical course of myeloma patients over a long-term follow-up period (8.5 year average). Seven myeloma cases treated with immuno-chemotherapy at our institution were analyzed with clinical courses and the results of FISH and G-band analyses. Furthermore, the target sequences in regard to 121 genes, related to driver mutations or acceleration of disease in myeloma, were performed using bone marrow myeloma samples by next-generation sequencing, Ion Proton™ System. We detected a relationship between an increase in the dominant mutated gene (e.g., TP53, DIS3, FAM46C, KDM6B, and EGR1) and poor prognosis. In particular, clonal escalation of the TP53 mutation could not be overcome by any treatment. The selection of a combination treatment conducted in conjunction with the monitoring of gene mutations is appropriate for long-term survival. Our data demonstrate that long-term follow-up of somatic gene mutations during the clinical course of myeloma is helpful in the development of an effective treatment strategy.

Molecular characteristics and functional differences of anti-PM/Scl autoantibodies and two other distinct and unique supramolecular structures known as "EXOSOMES"

The term "exosome" has been applied to three distinct supramolecular entities, namely the PM/Scl autoantibodies or "RNA exosomes", transforming DNA fragments termed "DNA exosomes", and small size extracellular vesicles knows as "exosomes". Some of the molecular components of the "PM/Scl exosome complex" or "RNA exosome" are recognized by specific autoantibodies present in the serum from some Systemic Sclerosis (SSc), polymyositis (PM) and polymyositis SSc (PM/Scl) overlap syndrome patients. On the other hand, one of the most active focuses of laboratory investigation in the last decade has been the biogenesis and role of extracellular vesicles known as "exosomes". The remarkable ability of these "exosome" vesicles to alter the cellular phenotype following fusion with target cells and the release of their macromolecular cargo has revealed a possible role in the pathogenesis of numerous diseases, including malignant, inflammatory, and autoimmune disorders and may allow them to serve as theranostic agents for personalized and precision medicine. The indiscriminate use of the term "exosome" to refer to these three distinct molecular entities has engendered great confusion in the scientific literature. Here, we review the molecular characteristics and functional differences between the three molecular structures identified as "exosomes". Given the rapidly growing scientific interest in extravesicular exosomes, unless a solution is found the confusion in the literature resulting from the use of the term "exosomes" will markedly increase.

Activating KRAS, NRAS, and BRAF mutants enhance proteasome capacity and reduce endoplasmic reticulum stress in multiple myeloma

KRAS, NRAS, and BRAF mutations which activate p44/42 mitogen-activated protein kinase (MAPK) signaling are found in half of myeloma patients and contribute to proteasome inhibitor (PI) resistance, but the underlying mechanisms are not fully understood. We established myeloma cell lines expressing wild-type (WT), constitutively active (CA) (G12V/G13D/Q61H), or dominant-negative (DN) (S17N)-KRAS and -NRAS, or BRAF-V600E. Cells expressing CA mutants showed increased proteasome maturation protein (POMP) and nuclear factor (erythroid-derived 2)-like 2 (NRF2) expression. This correlated with an increase in catalytically active proteasome subunit β (PSMB)-8, PSMB9, and PSMB10, which occurred in an ETS transcription factor-dependent manner. Proteasome chymotrypsin-like, trypsin-like, and caspase-like activities were increased, and this enhanced capacity reduced PI sensitivity, while DN-KRAS and DN-NRAS did the opposite. Pharmacologic RAF or MAPK kinase (MEK) inhibitors decreased proteasome activity, and sensitized myeloma cells to PIs. CA-KRAS, CA-NRAS, and CA-BRAF down-regulated expression of endoplasmic reticulum (ER) stress proteins, and reduced unfolded protein response activation, while DN mutations increased both. Finally, a bortezomib (BTZ)/MEK inhibitor combination showed enhanced activity in vivo specifically in CA-NRAS models. Taken together, the data support the hypothesis that activating MAPK pathway mutations enhance PI resistance by increasing proteasome capacity, and provide a rationale for targeting such patients with PI/RAF or PI/MEK inhibitor combinations. Moreover, they argue these mutations promote myeloma survival by reducing cellular stress, thereby distancing plasma cells from the apoptotic threshold, potentially explaining their high frequency in myeloma.

Genome instability in multiple myeloma

Multiple myeloma (MM) is an incurable plasma cell malignancy characterized by clonal proliferation of plasma cells and a heterogenous genomic landscape. Copy number and structural changes due to chromosomal instability (CIN) are common features of MM. In this review, we describe how primary and secondary genetic events caused by CIN can contribute to increased instability across the genome of malignant plasma cells; with a focus on specific driver genomic events, and how they interfere with cell-cycle checkpoints, to prompt accelerated proliferation. We also provide insight into other forms of CIN, such as chromothripsis and chromoplexy. We evaluate how the tumor microenvironment can contribute to a further increase in chromosomal instability in myeloma cells. Lastly, we highlight the role of certain mutational signatures in leading to high mutation rate and genome instability in certain MM patients. We suggest that assessing CIN in MM and its precursors states may help improve predicting the risk of progression to symptomatic disease and relapse and identifying future therapeutic targets.

Serum-free light chains combined with the Revised International Staging System could further distinguish the superior and inferior clinical outcome of multiple myeloma patients

The Revised International Staging System (R-ISS) was introduced as a powerful prognostic system to stratify patients with newly diagnosed multiple myeloma (NDMM). The serum-free light chain (sFLC) has been developed as a valuable marker to monitor multiple myeloma (MM) progression and response. Therefore, it is imperative to combine R-ISS and sFLC prognostic factors as modified R-ISS (MR-ISS) to better stratify patients into homogeneous survival subgroups, especially to further distinguish the high-risk MM patients who are likely to experience rapid progression or relapse. A total of 595 patients with NDMM were studied retrospectively. We performed the K-adaptive partitioning in 595 NDMM patients to define the MR-ISS classification: stage I includes R-ISS stage I and sFLC ratio < 80 (n = 66); stage III includes R-ISS stage III with sFLC ratio ≥ 80 (n = 87); stage II includes all the remaining conditions (n = 442). The median OS was not reached for MR-ISS stage I, 48.67 months for stage II, and 21.13 months for stage III. A significant OS difference of MR-ISS stage I and III patients has a particularly superior and inferior outcome compared with R-ISS stage I and III, respectively, which showed the similar results in PFS analysis. Validation of results was performed in an independent cohort. Our data indicate that the MR-ISS provides an improved prognostic power compared with R-ISS.

Cell-free DNA for genomic profiling and minimal residual disease monitoring in Myeloma- are we there yet?

OBJECTIVE

Multiple myeloma (MM), a plasma cell neoplasm, afflicts elder individuals accounting for 10% of hematologic malignancies. The MM plasma cells largely reside within the bone marrow niche and are accessible through an invasive bone marrow biopsy, which is challenging during serial monitoring of patients. In this setting, cell free DNA (cfDNA) may have a role to ascertain the molecular aberrations at diagnosis and in assessment of residual disease during therapy. The aim of this review was to explore the utility and current status of cfDNA in MM.

METHOD

PubMed was searched with terms including cell-free DNA, circulating-tumor DNA, Multiple Myeloma, diagnosis, genomic profiling, Minimal Residual Disease individually or in combination to shortlist the relevant studies.

RESULT

cfDNA serves as a non-invasive source of tumor-specific molecular biomarker, ctDNA that has immense potential in facilitating management of cancer patients. The mutation detection platforms for ctDNA include hybrid capture and ultra-deep sequencing. Hybrid capture allows full length gene sequencing for mutation and CNV detection. The disease progression can be monitored by profiling prognostic somatic copy number alterations by ultra-low pass whole genome sequencing of ctDNA cost-effectively. Evolution of both the laboratory protocols and bioinformatics tools may further improve the sensitivity of ctDNA detection for better disease management. Only a limited number of studies were available in MM exploring the potential utility of cfDNA.

CONCLUSION

In this review, we discuss the nuances and challenges associated with molecular evaluation of cfDNA and its potential role in diagnosis and monitoring of treatment response in MM.

Clonal hematopoiesis is associated with adverse outcomes in multiple myeloma patients undergoing transplant

Multiple myeloma (MM) is a plasma-cell neoplasm that is treated with high-dose chemotherapy, autologous stem cell transplant (ASCT) and long-term immunomodulatory drug (IMiD) maintenance. The presence of somatic mutations in the peripheral blood is termed clonal hematopoiesis of indeterminate potential (CHIP) and is associated with adverse outcomes. Targeted sequencing of the stem cell product from 629 MM patients treated by ASCT at the Dana-Farber Cancer Institute (2003–2011) detects CHIP in 136/629 patients (21.6%). The most commonly mutated genes are DNMT3A, TET2, TP53, ASXL1 and PPM1D. Twenty-one from fifty-six patients (3.3%) receiving first-line IMiD maintenance develop a therapy-related myeloid neoplasm (TMN). However, regardless of CHIP status, the use of IMiD maintenance associates with improved PFS and OS. In those not receiving IMiD maintenance, CHIP is associated with decreased overall survival (OS) (HR:1.34, p = 0.02) and progression free survival (PFS) (HR:1.45, p < 0.001) due to an increase in MM progression.

Multiple myeloma (MM) is treated with induction chemotherapy, autologous stem cell transplant (ASCT) and long-term immunomodulatory drug (IMiD) maintenance. Here, the authors show that the presence of clonal haematopoiesis of indeterminate potential (CHIP) at time of ASCT is associated with adverse outcomes in MM patients.

Genomic Instability in Multiple Myeloma

Genomic instability (GIN), an increased tendency to acquire genomic alterations, is a cancer hallmark. However, its frequency, underlying causes, and disease relevance vary across different cancers. Multiple myeloma (MM), a plasma cell malignancy, evolves through premalignant phases characterized by genomic abnormalities. Next-generation sequencing (NGS) methods are deconstructing the genomic landscape of MM across the continuum of its development, inextricably linking malignant transformation and disease progression with increasing acquisition of genomic alterations, and illuminating the mechanisms that generate these alterations. Although GIN drives disease evolution, it also creates vulnerabilities such as dependencies on 'superfluous' repair mechanisms and the induction of tumor-specific antigens that can be targeted. We review the mechanisms of GIN in MM, the associated vulnerabilities, and therapeutic targeting strategies.

Frequent upregulation of G9a promotes RelB-dependent proliferation and survival in multiple myeloma

Background

Multiple myeloma is an incurable hematological malignancy characterized by a heterogeneous genetic and epigenetic landscape. Although a number of genetic aberrations associated with myeloma pathogenesis, progression and prognosis have been well characterized, the role of many epigenetic aberrations in multiple myeloma remain elusive. G9a, a histone methyltransferase, has been found to promote disease progression, proliferation and metastasis via diverse mechanisms in several cancers. A role for G9a in multiple myeloma, however, has not been previously explored.

Methods

Expression levels of G9a/EHMT2 of multiple myeloma cell lines and control cells Peripheral Blood Mononuclear Cells (PBMCs) were analyzed. Correlation of G9a expression and overall survival of multiple myeloma patients were analyzed using patient sample database. To further study the function of G9a in multiple myeloma, G9a depleted multiple myeloma cells were built by lentiviral transduction, of which proliferation, colony formation assays as well as tumorigenesis were measured. RNA-seq of G9a depleted multiple myeloma with controls were performed to explore the downstream mechanism of G9a regulation in multiple myeloma.

Results

G9a is upregulated in a range of multiple myeloma cell lines. G9a expression portends poorer survival outcomes in a cohort of multiple myeloma patients. Depletion of G9a inhibited proliferation and tumorigenesis in multiple myeloma. RelB was significantly downregulated by G9a depletion or small molecule inhibition of G9a/GLP inhibitor UNC0642, inducing transcription of proapoptotic genes Bim and BMF. Rescuing RelB eliminated the inhibition in proliferation and tumorigenesis by G9a depletion.

Conclusions

In this study, we demonstrated that G9a is upregulated in most multiple myeloma cell lines. Furthermore, G9a loss-of-function analysis provided evidence that G9a contributes to multiple myeloma cell survival and proliferation. This study found that G9a interacts with NF-κB pathway as a key regulator of RelB in multiple myeloma and regulates RelB-dependent multiple myeloma survival. G9a therefore is a promising therapeutic target for multiple myeloma.

Structural and Functional Analyses of the FAM46C/Plk4 Complex

FAM46C, a non-canonical poly(A) polymerase, is frequently mutated in multiple myeloma. Loss of function of FAM46C promotes cell survival of multiple myeloma, suggesting a tumor-suppressive role. FAM46C is also essential for fastening sperm head and flagellum, indispensable for male fertility. The molecular mechanisms of these functions of FAM46C remain elusive. We report the crystal structure of FAM46C to provide the basis for its poly(A) polymerase activity and rationalize mutations associated with multiple myeloma. In addition, we found that FAM46C interacts directly with the serine/threonine kinase Plk4, the master regulator of centrosome duplication. We present the structure of FAM46C in complex with the Cryptic Polo-Box 1-2 domains of Plk4. Our structure-based mutational analyses show that the interaction with Plk4 recruits FAM46C to centrosomes. Our data suggest that Plk4-mediated localization of FAM46C enables its regulation of centrosome structure and functions, which may underlie the roles for FAM46C in cell proliferation and sperm development.

"Direct to Drug" screening as a precision medicine tool in multiple myeloma

Seventy-six FDA-approved oncology drugs and emerging therapeutics were evaluated in 25 multiple myeloma (MM) and 15 non-Hodgkin’s lymphoma cell lines and in 113 primary MM samples. Ex vivo drug sensitivities were mined for associations with clinical phenotype, cytogenetic, genetic mutation, and transcriptional profiles. In primary MM samples, proteasome inhibitors, dinaciclib, selinexor, venetoclax, auranofin, and histone deacetylating agents had the broadest cytotoxicity. Of interest, newly diagnosed patient samples were globally less sensitive especially to bromodomain inhibitors, inhibitors of receptor tyrosine kinases or non-receptor kinases, and DNA synthesis inhibitors. Clustering demonstrated six broad groupings of drug sensitivity linked with genomic biomarkers and clinical outcomes. For example, our findings mimic clinical observations of increased venetoclax responsiveness in t(11;14) patients but also identify an increased sensitivity profile in untreated patients, standard genetic risk, low plasma cell S-Phase, and in the absence of Gain(1q) and t(4;14). In contrast, increased ex vivo responsiveness to selinexor was associated with biomarkers of poor prognosis and later relapse patients. This “direct to drug” screening resource, paired with functional genomics, has the potential to successfully direct appropriate individualized therapeutic approaches in MM and to enrich clinical trials for likely responders.

Genomic analysis of multiple myeloma using targeted capture sequencing in the Japanese cohort

Previous genomic studies have revealed the genomic landscape of myeloma cells. Although some of the genomic abnormalities shown are believed to be correlated to the molecular pathogenesis of multiple myeloma and/or clinical outcome, these correlations are not fully understood. The aim of this study is to elucidate the correlation between genomic abnormalities and clinical characteristics by targeted capture sequencing in the Japanese multiple myeloma cohort. We analysed 154 patients with newly diagnosed multiple myeloma. The analysis revealed that the study cohort consisted of a less frequent hyperdiploid subtype (37·0%) with relatively high frequencies of KRAS mutation (36·4%) and IGH-CCND1 translocation (26·6%) compared with previous reports. Moreover, our targeted capture sequencing strategy was able to detect rare IGH-associated chromosomal translocations, such as IGH-CCND2 and IGH-MAFA. Interestingly, all 10 patients harboured MAX mutations accompanied by 14q23 deletion. The patients with del(17p) exhibited an unfavourable clinical outcome, and the presence of KRAS mutation was associated with shorter survival in patients with multiple myeloma, harbouring IGH-CCND1. Thus, our study provides a detailed landscape of genomic abnormalities, which may have potential clinical application for patients with multiple myeloma.

Bispecific, T-Cell-Recruiting Antibodies in B-Cell Malignancies

Bispecific antibodies (BsAbs) are designed to recognize and bind to two different antigens or epitopes. In the last few decades, BsAbs have been developed within the context of cancer therapies and in particular for the treatment of hematologic B-cell malignancies. To date, more than one hundred different BsAb formats exist, including bispecific T-cell engagers (BiTEs), and new constructs are constantly emerging. Advances in protein engineering have enabled the creation of BsAbs with specific mechanisms of action and clinical applications. Moreover, a better understanding of resistance and evasion mechanisms, as well as advances in the protein engineering and in immunology, will help generating a greater variety of BsAbs to treat various cancer types. This review focuses on T-cell-engaging BsAbs and more precisely on the various BsAb formats currently being studied in the context of B-cell malignancies, on ongoing clinical trials and on the clinical concerns to be taken into account in the development of new BsAbs.

MicroRNA-146b overexpression associates with deteriorated clinical characteristics, increased International Staging System stage, cacoethic chromosome abnormality, and unfavorable prognosis in multiple myeloma patients

BACKGROUND

MicroRNA-146b (miR-146b) is a critical regulator and prognosis biomarker in several hematological malignancies, whereas its role in multiple myeloma (MM) was unclear. Therefore, this study aimed to investigate the significance of miR-146b in MM patients.

METHODS

The plasma cells were separated from bone marrow samples of 180 symptomatic MM patients (before treatment) and 50 healthy controls (HCs), and subsequently detected by reverse transcription-quantitative polymerase chain reaction for miR-146b expression.

RESULTS

MiR-146b was increased in MM patients compared with HCs (P < .001), and it predicted increased MM risk (area under curve (AUC): 0.879, 95% confidence interval (CI): 0.822-0.936). For clinical parameters, miR-146b was positively correlated with serum creatinine (P = .047), beta-2-microglobulin (P < .001), lactate dehydrogenase (P < .001), bone lesion (P = .027), International Staging System (ISS) stage (P < .001), and t (4; 14; P = .006), while negatively correlated with albumin (P = .004) in MM patients. For prognosis, miR-146b was decreased in complete response (CR) patients compared with non-CR patients (P = .025), as well as in overall response rate (ORR) patients compared with non-ORR patients (P = .036), and it discriminated CR patients from non-CR patients (AUC: 0.610, 95% CI: 0.523-0.698) and distinguished ORR patients from non-ORR patients (AUC: 0.602, 95% CI: 0.501-0.703) in MM patients. Moreover, miR-146b was correlated with worse progression-free survival (P = .007) and overall survival (P = .014) in MM patients.

CONCLUSION

MiR-146b was overexpressed in MM patients and predicted increased MM risk; meanwhile, it correlated with deteriorated clinical properties, increased ISS stage, cacoethic chromosome abnormality, and worse prognosis in MM patients.

Biallelic loss of FAM46C triggers tumor growth with concomitant activation of Akt signaling in multiple myeloma cells

Loss of heterozygosity or mutation of the family with sequence similarity 46, member C (FAM46C) gene on chromosome band 1p12 is associated with shorter overall survival of patients with multiple myeloma (MM). In this study, using human MM cell lines (KMS‐11, OCI‐My5, and ANBL‐6), we generated FAM46C^−/− cell clones and examined the effect of disruption of FAM46C on cell survival and cellular signaling. Cell proliferation assays showed increased clonogenicity of FAM46C^−/− KMS‐11 cells compared to WT cells. Xenograft experiments showed significantly shorter overall survival of mice harboring the FAM46C^−/− cell‐derived tumors than mice with the FAM46C^WT cell‐derived tumors. Notably, levels of phosphorylated Akt and its substrates increased both in vitro and in vivo in the FAM46C^−/− cells compared to WT cells. In addition, caspase activities decreased in the FAM46C^−/− cells. Results of gene set enrichment analysis showed that loss of FAM46C significantly activated serum‐responsive genes while inactivating phosphatase and tensin homolog (PTEN)‐related genes. Mechanistically, loss of FAM46C decreased the PTEN activity, number of apoptotic cells, and caspase activities. PF‐04691502, a selective PI3K inhibitor, suppressed the augmented phosphorylation of Akt and its substrate FoxO3a. Treatment with afuresertib (a specific Akt inhibitor) in combination with bortezomib additively decreased FAM46C^−/− MM cell survival. Collectively, this study is the first to report that loss of FAM46C triggers the concomitant activation of the PI3K‐Akt signaling pathway, which might be a therapeutic target for MM with abnormalities in the FAM46C gene.

Liquid biopsies for multiple myeloma in a time of precision medicine

Multiple myeloma (MM) is a challenging, progressive, and highly heterogeneous hematological malignancy. MM is characterized by multifocal proliferation of neoplastic plasma cells in the bone marrow (BM) and sometimes in extramedullary organs. Despite the availability of novel drugs and the longer median overall survival, some patients survive more than 10 years while others die rapidly. This heterogeneity is mainly driven by biological characteristics of MM cells, including genetic abnormalities. Disease progressions are mainly due to the inability of drugs to overcome refractory disease and inevitable drug-resistant relapse. In clinical practice, a bone marrow biopsy, mostly performed in one site, is still used to access the genetics of MM. However, BM biopsy use is limited by its invasive nature and by often not accurately reflecting the mutational profile of MM. Recent insights into the genetic landscape of MM provide a valuable opportunity to implement precision medicine approaches aiming to enable better patient profiling and selection of targeted therapies. In this review, we explore the use of the emerging field of liquid biopsies in myeloma patients considering current unmet medical needs, such as assessing the dynamic mutational landscape of myeloma, early predictors of treatment response, and a less invasive response monitoring.

hsa_circRNA_101237: A Novel Diagnostic and Prognostic Biomarker and Potential Therapeutic Target for Multiple Myeloma

Background

It has been demonstrated that circular RNA (circRNA) plays a crucial role in the occurrence and development of tumors, but the diagnostic and predictive value of most circRNAs in tumor patients remains unclear, especially for multiple myeloma (MM).

Methods

High-throughput circRNA microarray-based sequencing was used to identify the differentially expressed circRNAs in MM. qRT-PCR was then employed to detect hsa_circRNA_101237 expression levels in the bone marrow tissues from 143 MM patients (65 first-episode treatment-naive patients and 78 patients with recurrent/refractory disease), MM cells and bortezomib-resistant MM cell lines. Whether hsa_circRNA_101237 can be used as a potential biomarker and therapeutic target for MM was investigated.

Results

The average expressions of hsa_circRNA_101237 in the bone marrow tissues from MM patients (especially those with recurrent/refractory disease), MM cells and bortezomib-resistant MM cell lines were increased significantly (P<0.01). hsa_circRNA_101237 was overexpressed in patients positive for 13q14 deletion, 1q21 amplification, P53 deletion, and t(4,14) and t(14,16). hsa_circRNA_101237 was closely related to prognosis of the patients, and its high expression was associated with shorter OS and PFS. In addition, those overexpressing hsa_circRNA_101237 were less responsive to bortezomib treatment. Bioinformatic analysis indicated that hsa_circRNA_101237 interacted with 11 miRNAs and 10 candidate mRNAs. This finding may shed new light on the subsequent studies on the working mechanism and functions.

Conclusion

It was first reported that hsa_circRNA_101237 was significantly upregulated in MM. It was indicated that hsa_circRNA_101237 may be a novel biomarker for MM, and it plays a significant role in the occurrence and development of MM.

RAS/RAF mutations in tumor samples and cell-free DNA from plasma and bone marrow aspirates in multiple myeloma patients

Purpose: To evaluate the detection of gene mutations in bone marrow biopsy and circulating free DNA (cfDNA) from plasma in multiple myeloma (MM). Experimental design: We used cell-free DNA from plasma and bone marrow to test BRAF V600, KRAS G12/G13, NRAS G12/G13 and NRAS Q61 mutations using multiplex assays for droplet digital PCR (ddPCR), and evaluated results with clinical outcomes. Results: We found of 83 patients, the detectable mutation frequencies for the above four genes were 4 (5%), 13 (16%), 3 (4%) and 14 (17%) in bone marrow, respectively. The median variant allelic frequency (VAF) in most mutations were 1.595%. In 17 paired cfDNA samples, the detectable mutation frequencies for the above four genes were 5 (30%), 1 (6%), 0 (0%) and 3 (18%) respectively, and the median VAF rate was 2.9%. Agreement between bone marrow DNA and plasma cfDNA were 76%, 100%, 100% and 100% compared to the tissue detections, respectively. In 17 patients with paired bone marrow and plasma samples, the above four mutations were 3 (18%), 1 (6%), 0 (0%) and 2 (12%) respectively, with the agreement rates of 88%, 88%, 100% and 100% compared to tissue detections. Of 57 patients with available outcome data, high mutation VAF had a shorter median survival than patients with low mutation VAF (P=0.0322). Conclusions: Oncogenic mutations in BRAF, KRAS and NRAS genes can be detected in the bone marrow and plasma cfDNA with ddPCR in patients with MM patients and high VAF is associated with short survival.

Risk-Based Therapeutic Strategies

Although therapeutic strategies have been adapted to age and comorbidities of myeloma patients for a long time, all patients currently experiment the same treatment whatever their genomic risk. However, high-risk patients should benefit right now from the most efficient drugs combinations. Herein, we review and discuss how to optimally define risk to adapt treatment and why a modern multiparametric definition of genomic risk is urgently needed. Minimal residual disease status will probably also take a growing place in patient's management, including in treatment adaptation. We also discuss how next-generation sequencing will definitively represent an essential tool to manage risk-based therapeutic strategies. Finally, despite an explosive knowledge of myeloma molecular landscape, targeted therapy perspectives remain poor, with only few exceptions.

Targeted Management Strategies in Multiple Myeloma

There has been a paradigm shift in the treatment of myeloma triggered by intense exploration of the disease biology to understand the basis of disease development and progression and the evolution of newly diagnosed myeloma to a multidrug refractory state that is associated with poor survival. These studies have in turn informed us of potential therapeutic strategies in our ongoing effort to cure this disease, or at a minimum convert it into a chronic disease. Given the clonal evolution that leads to development of drug resistance and treatment failure, identification of specific genetic abnormalities and approaches to target these abnormalities have been on the top of the list for some time. The more recent studies examining the genome of the myeloma cell have led to development of umbrella trials that assigns patients to specific targeted agents based on the genomic abnormality. In addition, other approaches to targeting myeloma such as monoclonal antibodies are already in the clinic and are being used in all stages of disease, typically in combination with other therapies. As the therapeutic strategy evolves and we have a larger arsenal of targeted agents, we will be able to use judicious combination of drugs based on specific tumor characteristics assessed through genomic interrogation or other biologic targets. Such targeted approaches are likely to evolve to become the mainstay of myeloma therapies in the future.

The Role of Polycomb Repressive Complex in Malignant Peripheral Nerve Sheath Tumor

Malignant peripheral nerve sheath tumors (MPNSTs) are aggressive soft tissue sarcomas that can arise most frequently in patients with neurofibromatosis type 1 (NF1). Despite an increasing understanding of the molecular mechanisms that underlie these tumors, there remains limited therapeutic options for this aggressive disease. One potentially critical finding is that a significant proportion of MPNSTs exhibit recurrent mutations in the genes EED or SUZ12, which are key components of the polycomb repressive complex 2 (PRC2). Tumors harboring these genetic lesions lose the marker of transcriptional repression, trimethylation of lysine residue 27 on histone H3 (H3K27me3) and have dysregulated oncogenic signaling. Given the recurrence of PRC2 alterations, intensive research efforts are now underway with a focus on detailing the epigenetic and transcriptomic consequences of PRC2 loss as well as development of novel therapeutic strategies for targeting these lesions. In this review article, we will summarize the recent findings of PRC2 in MPNST tumorigenesis, including highlighting the functions of PRC2 in normal Schwann cell development and nerve injury repair, as well as provide commentary on the potential therapeutic vulnerabilities of a PRC2 deficient tumor cell.

DCEP and bendamustine/prednisone as salvage therapy for quad- and penta-refractory multiple myeloma

Multiple myeloma (MM) almost invariably progresses through novel therapies. Patients with quad-refractory MM (refractory to bortezomib, carfilzomib, lenalidomide, and pomalidomide) and penta-refractory MM (additional refractoriness to daratumumab) have few treatment options. Two chemotherapy regimens, bendamustine/prednisone (BP) and dexamethasone, cyclophosphamide, etoposide, and cisplatin (DCEP), are often used in quad- and penta-refractory MM, but there are limited data on outcomes in this heavily pre-treated population. We conducted a single-center retrospective study to identify all patients who received DCEP and/or BP for quad- or penta-refractory MM. Disease response and refractoriness were defined by International Myeloma Working Group criteria. The primary endpoint was overall response rate (ORR). Secondary endpoints included overall survival (OS), progression-free survival (PFS), and duration of response (DOR). We identified 27 patients who received BP for quad- or penta-refractory MM. The median number of prior lines of therapy was 6. The ORR for BP was 26%. The median PFS for BP was 1.4 months (95% CI 1.1-1.6) and median OS was 8.7 months (95% CI 2.3-15.0). Patients treated with cyclophosphamide had less response to BP. Thirty-one patients received DCEP for quad-refractory or penta-refractory MM. The median number of prior treatment regimens was 8. The ORR to DCEP was 35%. The median PFS was 2.7 months (95% CI 1.5-3.8) and median OS was 6.2 months (95% CI 4.4-7.8). DCEP and BP retain efficacy in quad- and penta-refractory MM. Our analysis supports prospective study of these regimens, possibly in combination or in comparison with other agents in this area of unmet need.

Genomic profiling in amyloid light-chain amyloidosis reveals mutation profiles associated with overall survival

Background: Amyloid light chain (AL) amyloidosis is characterized by tissue deposition of amyloid fibres derived from immunoglobulin that can lead to irreversible organ damage. Information about genomic profiles of AL amyloidosis is lacking.Methods: In this study, we adopted a two-step strategy to investigate the mutational profile of AL amyloidosis bone marrow plasma cells (PCs) and their clinical implications. In step one, whole-exome sequencing was performed in bone marrow PCs and paired with normal tissue from 10 AL amyloidosis patients, by which we identified 10 significantly mutated genes (SMGs). In step two, we constituted a targeted gene sequencing (TGS) panel covering the frequently mutated genes identified in step one, genes reported in prior AL amyloidosis studies, and known cancer driver mutations. Then, we analysed an expanded cohort of AL amyloidosis patients (N = 48) with this panel comprising 98 genes.Results: Four recurrent mutations were identified by TGS and verified by Sanger sequencing: ASB15 (c. 844 C > T), ASCC3 (c. 1595 A > G), HIST1H1E (c. 311 C > T) and KRAS (c. 35 G > A), among which the first three mutations were associated with inferior overall survival (OS). Additionally, we found that the number of mutations identified by the TGS panel of 98 genes could be a prognostic predictor for OS.Conclusions: In summary, we revealed genomic profiling in AL amyloidosis and found mutation profiles associated with OS.

Reconstructing the evolutionary history of multiple myeloma

Multiple myeloma is the second most common lymphoproliferative disorder, characterized by aberrant expansion of monoclonal plasma cells. In the last years, thanks to novel next generation sequencing technologies, multiple myeloma has emerged as one of the most complex hematological cancers, shaped over time by the activity of multiple mutational processes and by the acquisition of key driver events. In this review, we describe how whole genome sequencing is emerging as a key technology to decipher this complexity at every stage of myeloma development: precursors, diagnosis and relapsed/refractory. Defining the time windows when driver events are acquired improves our understanding of cancer etiology and paves the way for early diagnosis and ultimately prevention.

CD27 antigen negative expression indicates poor prognosis in newly diagnosed multiple myeloma

To investigate the role of CD27 in multiple myeloma(MM), bone marrow samples from 165 newly diagnosed MM were analysed by flow cytometry. CD27- group (n = 93) had higher level of plasma cell proportion (37.00% vs 22.50%, p < .05), β2-MG (5.42 vs 3.20 mg/L, p < .05), calcium (2.45 vs 2.28 mmol/L, p < .05),higher percentage of ISS stage III (49.46% vs 22.22%, p < .05) and patients with ≥2 high-risk cytogenetics (24.73% vs 15.28%, p < .05) than CD27+ group (n = 72). After 4 cycles of chemotherapy, the overall response rate in CD27- group were lower than CD27+ group (56.67% vs 73.02%,p < .05). After a median follow-up of 18 months, progression-free survival was significantly shorter in CD27- group than in CD27+ group (22 vs 40 months, p < .05), so was overall survival (median OS not reached, p < .05). Gene sequencing showed more adverse mutations in CD27- group than CD27+ group.

Next-Generation Sequencing for Clinical Management of Multiple Myeloma: Ready for Prime Time?

Personalized treatment is an attractive strategy that promises increased efficacy with reduced side effects in cancer. The feasibility of such an approach has been greatly boosted by next-generation sequencing (NGS) techniques, which can return detailed information on the genome and on the transcriptome of each patient's tumor, thus highlighting biomarkers of response or druggable targets that may differ from case to case. However, while the number of cancers sequenced is growing exponentially, much fewer cases are amenable to a molecularly-guided treatment outside of clinical trials to date. In multiple myeloma, genomic analysis shows a variety of gene mutations, aneuploidies, segmental copy-number changes, translocations that are extremely heterogeneous, and more numerous than other hematological malignancies. Currently, in routine clinical practice we employ reduced FISH panels that only capture three high-risk features as part of the R-ISS. On the contrary, recent advances have suggested that extending genomic analysis to the full spectrum of recurrent mutations and structural abnormalities in multiple myeloma may have biological and clinical implications. Furthermore, increased efficacy of novel treatments can now produce deeper responses, and standard methods do not have enough sensitivity to stratify patients in complete biochemical remission. Consequently, NGS techniques have been developed to monitor the size of the clone to a sensitivity of up to a cell in a million after treatment. However, even these techniques are not within reach of standard laboratories. In this review we will recapitulate recent advances in multiple myeloma genomics, with special focus on the ones that may have immediate translational impact. We will analyze the benefits and pitfalls of NGS-based diagnostics, highlighting crucial aspects that will need to be taken into account before this can be implemented in most laboratories. We will make the point that a new era in myeloma diagnostics and minimal residual disease monitoring is close and conventional genetic testing will not be able to return the required information. This will mandate that even in routine practice NGS should soon be adopted owing to a higher informative potential with increasing clinical benefits.

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.

GLIPR1 expression is reduced in multiple myeloma but is not a tumour suppressor in mice

Multiple myeloma, a plasma cell malignancy, is a genetically heterogeneous disease and the genetic factors that contribute to its development and progression remain to be fully elucidated. The tumour suppressor gene GLIPR1 has previously been shown to be deleted in approximately 10% of myeloma patients, to inhibit the development of plasma cell tumours in ageing mice and to have reduced expression levels in the plasma cells of patients with light-chain amyloidosis, a myeloma-related malignancy. Therefore, we hypothesised that GLIPR1 may have tumour suppressor activity in multiple myeloma. In this study, we demonstrate that plasma cell expression of GLIPR1 is reduced in the majority of myeloma patients and Glipr1 expression is lost in the 5TGM1 murine myeloma cell line. However, overexpression of GLIPR1 in a human myeloma cell line did not affect cell proliferation in vitro. Similarly, re-expression of Glipr1 in 5TGM1 cells did not significantly reduce their in vitro proliferation or in vivo growth in C57BL/KaLwRij mice. In addition, using CRISPR-Cas9 genome editing, we generated C57BL/Glipr1-/- mice and showed that loss of Glipr1 in vivo did not affect normal haematopoiesis or the development of monoclonal plasma cell expansions in these mice up to one year of age. Taken together, our results suggest that GLIPR1 is unlikely to be a potent tumour suppressor in multiple myeloma. However, it remains possible that the down-regulation of GLIPR1 may cooperate with other genetic lesions to promote the development of myeloma.

Genomic profiling of multiple myeloma: New insights and modern technologies

Advances in technologies for genomic profiling, primarily with next generation sequencing, have lead to a better understanding of the complex genomic landscape in multiple myeloma. Integrated analysis of whole genome, exome and transcriptome sequencing has lead to new insights on disease drivers including translocations, copy number alterations, somatic mutations, and altered gene expression. Disease progression in multiple myeloma is largely driven by structural variations including the traditional immunoglobulin heavy chain (IGH) translocations and hyperdiploidy which are early events in myelomagenesis as well as more complex events spanning over multiple chromosomes and involving amplifications and deletions. In this review, we will discuss recent insights on the genomic landscape of multiple myeloma and their implications for disease progression and personalized treatment. We will review how sequencing assays compare to current clinical methods and give an overview of modern technologies for interrogating genomic aberrations.

The RNA Exosome and Human Disease

The evolutionarily conserved RNA exosome is a multisubunit ribonuclease complex that processes and/or degrades numerous RNAs. Recently, mutations in genes encoding both structural and catalytic subunits of the RNA exosome have been linked to human disease. Mutations in the structural exosome gene EXOSC2 cause a distinct syndrome that includes retinitis pigmentosa, hearing loss, and mild intellectual disability. In contrast, mutations in the structural exosome genes EXOSC3 and EXOSC8 cause pontocerebellar hypoplasia type 1b (PCH1b) and type 1c (PCH1c), respectively, which are related autosomal recessive, neurodegenerative diseases. In addition, mutations in the structural exosome gene EXOSC9 cause a PCH-like disease with cerebellar atrophy and spinal motor neuronopathy. Finally, mutations in the catalytic exosome gene DIS3 have been linked to multiple myeloma, a neoplasm of plasma B cells. How mutations in these RNA exosome genes lead to distinct, tissue-specific diseases is not currently well understood. In this chapter, we examine the role of the RNA exosome complex in human disease and discuss the mechanisms by which mutations in different exosome subunit genes could impair RNA exosome function and give rise to diverse diseases.

Mate pair sequencing outperforms fluorescence in situ hybridization in the genomic characterization of multiple myeloma

Fluorescence in situ hybridization (FISH) is currently the gold-standard assay to detect recurrent genomic abnormalities of prognostic significance in multiple myeloma (MM). Since most translocations in MM involve a position effect with heterogeneous breakpoints, we hypothesize that FISH has the potential to miss translocations involving these regions. We evaluated 70 bone marrow samples from patients with plasma cell dyscrasia by FISH and whole-genome mate-pair sequencing (MPseq). Thirty cases (42.9%) displayed at least one instance of discordance between FISH and MPseq for each primary and secondary abnormality evaluated. Nine cases had abnormalities detected by FISH that went undetected by MPseq including 6 tetraploid clones and three cases with missed copy number abnormalities. In contrast, 19 cases had abnormalities detected by MPseq that went undetected by FISH. Seventeen were MYC rearrangements and two were 17p deletions. MPseq identified 36 MYC abnormalities and 17 (50.0% of MYC abnormal group with FISH results) displayed a false negative FISH result. MPseq identified 10 cases (14.3%) with IgL rearrangements, a recent marker of poor outcome, and 10% with abnormalities in genes associated with lenalidomide response or resistance. In summary, MPseq was superior in the characterization of rearrangement complexity and identification of secondary abnormalities demonstrating increased clinical value compared to FISH.