Presence of a p53 Gene Deletion in Patients With Multiple Myeloma Predicts for Short Survival After Conventional-Dose Chemotherapy

Inhibition of Myeloma Cell Function by Cannabinoid-Enriched Product Associated With Regulation of Telomere and TP53

Multiple myeloma is a hematological cancer caused by the uncontrolled proliferation of abnormal plasma cells in the bone marrow, leading to excessive immunoglobulin production. Our study aimed to examine the anticancer properties of BRF1A, a cannabinoid (CBD)-enriched product, on 2 myeloma cell lines: U266 and ARH-7. We treated U266 and ARH-77 myeloma cells with varying doses of BRF1A and measured the production of IgE and IgG antibodies using ELISA. Cell viability was assessed using trypan blue and CCK-8 assays. We measured the expression of genes related to the production of IgE and IgG antibodies, IgEH, and IgGH. We determined its effect on the expression of telomerase and its phosphorylated form as an indicator of telomere stabilization. Furthermore, we determined its effect on other cancer-related targets such as NF-ĸB, c-Myc, and TP53 in U266 cells using reverse transcription polymerase chain reaction (RT-PCR) and western blotting. BRF1A reduced myeloma cell IgE and IgG production in a time and dose-dependent manner. It also suppressed the expression of p-IκBα, p-NFκB (p65), and total NFκB protein, as well as XBP1u and XBP1s. It increased the gene and protein expression of telomere and hTERT and significantly increased cancer suppressor TP53 gene and p53 protein expression. Additionally, BRF1A decreased the c-Myc gene and protein expression. Our study has shown that a CBD-enriched product can reduce the growth of myeloma cells by suppressing the critical functions of IgE- and IgG-producing cells. This study could help bridge the gap in understanding how cannabinoid-containing products affect cancer, aging, telomere, and cancer-suppressor gene activity.

Identifying novel mechanisms of biallelic TP53 loss refines poor outcome for patients with multiple myeloma

Biallelic TP53 inactivation is the most important high-risk factor associated with poor survival in multiple myeloma. Classical biallelic TP53 inactivation has been defined as simultaneous mutation and copy number loss in most studies; however, numerous studies have demonstrated that other factors could lead to the inactivation of TP53. Here, we hypothesized that novel biallelic TP53 inactivated samples existed in the multiple myeloma population. A random forest regression model that exploited an expression signature of 16 differentially expressed genes between classical biallelic TP53 and TP53 wild-type samples was subsequently established and used to identify novel biallelic TP53 samples from monoallelic TP53 groups. The model reflected high accuracy and robust performance in newly diagnosed relapsed and refractory populations. Patient survival of classical and novel biallelic TP53 samples was consistently much worse than those with mono-allelic or wild-type TP53 status. We also demonstrated that some predicted biallelic TP53 samples simultaneously had copy number loss and aberrant splicing, resulting in overexpression of high-risk transcript variants, leading to biallelic inactivation. We discovered that splice site mutation and overexpression of the splicing factor MED18 were reasons for aberrant splicing. Taken together, our study unveiled the complex transcriptome of TP53, some of which might benefit future studies targeting abnormal TP53.

An evolutionary machine learning for multiple myeloma using Runge Kutta Optimizer from multi characteristic indexes

Multiple myeloma (MM) is a malignant plasma cell disease that is the second most prevalent hematological malignancy in high-income nations and accounts for around 1.8% of all cancers and 18% of hematologic malignancies in the United States. In this research, we try to design a machine learning framework for MM diagnosis from multi characteristic indexes using slime mould Runge Kutta Optimizer (MSRUN) and kernel extreme learning machine, which is called as MSRUN-KELM. An efficient slime mould learning operator is introduced to the initial Runge Kutta Optimizer in MSRUN, ensuring that the trade-off between intensity and diversity is satisfied. The MSRUN was evaluated using IEEE CEC2014 benchmark functions, and the statistical results indicate a significant increase in the search performance of MSRUN. In MSRUN-KELM, kernel extreme machine learning is constructed on MM from multi-characteristic indexes with MSRUN, parameter optimization, and feature selection synchronized by MSRUN. The results of MSRUN-KELM on MM are accuracy of 93.88%, a Matthews correlation coefficient of 0.922677, and sensitivities of 93.41% and 93.19%. The suggested MSRUN-KELM may be utilized to analyze MM from multi-characteristic indexes well, and it can be treated as a potential tool for MM diagnosis.

Molecular Diagnostic Testing for Hematopoietic Neoplasms: Linking Pathogenic Drivers to Personalized Diagnosis

Molecular diagnostics inhabit an increasingly central role in characterizing hematopoietic malignancies. This brief review summarizes the genomic targets important for many major categories of hematopoietic neoplasia by focusing on disease pathogenesis. In myeloid disease, recurrent mutations in key functional classes drive clonal hematopoiesis, on which additional variants can specify clinical presentation and accelerate progression. Lymphoblastic leukemias are frequently initiated by oncogenic fusions that block lymphoid maturation while, in concert with additional mutations, driving proliferation. The links between genetic aberrations and lymphoma patient outcomes have been clarified substantially through the clustering of genomic profiles. Finally, the addition of next-generation sequencing strategies to cytogenetics is refining risk stratification for plasma cell myeloma. In all categories, molecular diagnostics shed light on the unique mechanistic underpinnings of each individual malignancy, thereby empowering more rational, personalized care for these patients.

Inhibition of the Protein Arginine Methyltransferase PRMT5 in High-Risk Multiple Myeloma as a Novel Treatment Approach

Multiple myeloma (MM) is an incurable clonal plasma cell malignancy. Subsets of patients have high-risk features linked with dismal outcome. Therefore, the need for effective therapeutic options remains high. Here, we used bio-informatic tools to identify novel targets involved in DNA repair and epigenetics and which are associated with high-risk myeloma. The prognostic significance of the target genes was analyzed using publicly available gene expression data of MM patients (TT2/3 and HM cohorts). Hence, protein arginine methyltransferase 5 (PRMT5) was identified as a promising target. Druggability was assessed in OPM2, JJN3, AMO1 and XG7 human myeloma cell lines using the PRMT5-inhibitor EPZ015938. EPZ015938 strongly reduced the total symmetric-dimethyl arginine levels in all cell lines and lead to decreased cellular growth, supported by cell line dependent changes in cell cycle distribution. At later time points, apoptosis occurred, as evidenced by increased AnnexinV-positivity and cleavage of PARP and caspases. Transcriptome analysis revealed a role for PRMT5 in regulating alternative splicing, nonsense-mediated decay, DNA repair and PI3K/mTOR-signaling, irrespective of the cell line type. PRMT5 inhibition reduced the expression of upstream DNA repair kinases ATM and ATR, which may in part explain our observation that EPZ015938 and the DNA-alkylating agent, melphalan, have combinatory effects. Of interest, using a low-dose of mTOR-inhibitor, we observed that cell viability was partially rescued from the effects of EPZ015938, indicating a role for mTOR-related pathways in the anti-myeloma activity of EPZ015938. Moreover, PRMT5 was shown to be involved in splicing regulation of MMSET and SLAMF7, known genes of importance in MM disease. As such, we broaden the understanding of the exact role of PRMT5 in MM disease and further underline its use as a possible therapeutic target.

Multiple myeloma with high-risk cytogenetics and its treatment approach

Despite substantial advances in anti-myeloma treatments, early recurrence and death remain an issue in certain subpopulations. Cytogenetic abnormalities (CAs) are the most widely accepted predictors for poor prognosis in multiple myeloma (MM), such as t(4;14), t(14;16), t(14;20), gain/amp(1q21), del(1p), and del(17p). Co-existing high-risk CAs (HRCAs) tend to be associated with an even worse prognosis. Achievement of sustained minimal residual disease (MRD)-negativity has recently emerged as a surrogate for longer survival, regardless of cytogenetic risk. Information from newer clinical trials suggests that extended intensified treatment can help achieve MRD-negativity in patients with HRCAs, which may lead to improved outcomes. Therapy should be considered to include a 3- or 4-drug induction regimen (PI/IMiD/Dex or PI/IMiD/Dex/anti-CD38 antibody), auto-transplantation, and consolidation/maintenance with lenalidomide ± a PI. Results from ongoing clinical trials for enriched high-risk populations will reveal the precise efficacy of the investigated regimens. Genetic abnormalities of MM cells are intrinsic critical factors determining tumor characteristics, which reflect the natural course and drug sensitivity of the disease. This paper reviews the clinicopathological features of genomic abnormalities related to adverse prognosis, focusing on HRCAs that are the most relevant in clinical practice, and outline current optimal therapeutic approaches for newly diagnosed MM with HRCAs.

Treatment patterns and outcomes according to cytogenetic risk stratification in patients with multiple myeloma: a real-world analysis

A clearer understanding of the prognostic implications of t(11;14) in multiple myeloma (MM) is needed to inform current and future therapeutic options. We utilized real-world data from a US database to examine treatment patterns and outcomes in patients by t(11;14) status compared with high- and standard-risk subgroups across different lines of therapy (LoT). This retrospective, observational cohort study used de-identified patient-level information from adults with MM and first-line treatment initiation between January 2011 and January 2020, followed until February 2020. The high-risk cohort comprised patients with high-risk genetic abnormalities per mSMART criteria (including those with co-occurring t(11;14)). Among 6138 eligible patients, 6137, 3160, and 1654 received first-, second-, and third-line treatments, respectively. Of 645 patients who had t(11;14), 69.1% had t(11;14) alone, while 30.9% had co-occurring high-risk abnormalities. Altogether, 1624 and 2544 patients were classified as high- and standard-risk, respectively. In the absence of biomarker-driven therapy, treatment patterns remain similar across LoT in high-risk, t(11;14)+, and standard-risk subgroups. Across all LoT, patient outcomes in the high-risk subgroup were less favorable than those in the t(11;14)+ and standard-risk subgroups. Thus, there is an opportunity for novel therapeutics targeted to t(11;14) and other defined subgroups to personalize MM therapy and optimize patient outcomes.

Genetic Aberrations and Interaction of NEK2 and TP53 Accelerate Aggressiveness of Multiple Myeloma

It has been previously shown that (never in mitosis gene A)-related kinase 2 (NEK2) is upregulated in multiple myeloma (MM) and contributes to drug resistance. However, the mechanisms behind this upregulation remain poorly understood. In this study, it is found that amplification of NEK2 and hypermethylation of distal CpG islands in its promoter correlate strongly with increased NEK2 expression. Patients with NEK2 amplification have a poor rate of survival and often exhibit TP53 deletion, which is an independent prognostic factor in MM. This combination of TP53 knockout and NEK2 overexpression induces asymmetric mitosis, proliferation, drug resistance, and tumorigenic behaviors in MM in vitro and in vivo. In contrast, delivery of wild type p53 and suppression of NEK2 in TP53^-/- MM cell lines inhibit tumor formation and enhance the effect of Bortezomib against MM. It is also discovered that inactivating p53 elevates NEK2 expression genetically by inducing NEK2 amplification, transcriptionally by increased activity of cell cycle-related genes like E2F8 and epigenetically by upregulating DNA methyltransferases. Dual defects of TP53 and NEK2 may define patients with the poorest outcomes in MM with p53 inactivation, and NEK2 may serve as a novel therapeutic target in aggressive MM with p53 abnormalities.

How I Treat High-risk Multiple Myeloma

Survival of multiple myeloma (MM) has significantly improved over the last decade; however, a composed group of patients (15-20%), named high-risk (HR) MM, still experience reduced survival. Both tumor biology and suboptimal/absent responses to therapy may underlie HR definition and a clear uniform identification of risk factors is crucial for a proper management of these patients. In biologic-HRMM, MRD negativity attainment and sustain, inside and outside BM, should be the primary goal and therapy should be adapted in patients with frailty to reduce toxicity and improve quality of life. MM treatment has traditionally been tailored on age and more recently frailty or comorbidities, but very rarely on the biology of the disease, mainly because of the lack of a clear benefit derived from a specific drug/combination, inhomogeneity in HR definition and lack of data coming from prospective, properly designed clinical trials. Some attempts have been successfully made recently in this direction. In this review, we are discussing the current different definitions of HR and the need for a consensus, the results of available trials in HR patients and the way through risk-adapted treatment strategies. For this purpose, we are proposing several clinical cases of difficult-to-treat patients throughout different treatment phases.

Targeting the methyltransferase SETD8 impairs tumor cell survival and overcomes drug resistance independently of p53 status in multiple myeloma

Background

Multiple myeloma (MM) is a malignancy of plasma cells that largely remains incurable. The search for new therapeutic targets is therefore essential. In addition to a wide panel of genetic mutations, epigenetic alterations also appear as important players in the development of this cancer, thereby offering the possibility to reveal novel approaches and targets for effective therapeutic intervention.

Results

Here, we show that a higher expression of the lysine methyltransferase SETD8, which is responsible for the mono-methylation of histone H4 at lysine 20, is an adverse prognosis factor associated with a poor outcome in two cohorts of newly diagnosed patients. Primary malignant plasma cells are particularly addicted to the activity of this epigenetic enzyme. Indeed, the inhibition of SETD8 by the chemical compound UNC-0379 and the subsequent decrease in histone H4 methylation at lysine 20 are highly toxic in MM cells compared to normal cells from the bone marrow microenvironment. At the molecular level, RNA sequencing and functional studies revealed that SETD8 inhibition induces a mature non-proliferating plasma cell signature and, as observed in other cancers, triggers an activation of the tumor suppressor p53, which together cause an impairment of myeloma cell proliferation and survival. However, a deadly level of replicative stress was also observed in p53-deficient myeloma cells treated with UNC-0379, indicating that the cytotoxicity associated with SETD8 inhibition is not necessarily dependent on p53 activation. Consistent with this, UNC-0379 triggers a p53-independent nucleolar stress characterized by nucleolin delocalization and reduction of nucleolar RNA synthesis. Finally, we showed that SETD8 inhibition is strongly synergistic with melphalan and may overcome resistance to this alkylating agent widely used in MM treatment.

Conclusions

Altogether, our data indicate that the up-regulation of the epigenetic enzyme SETD8 is associated with a poor outcome and the deregulation of major signaling pathways in MM. Moreover, we provide evidences that myeloma cells are dependent on SETD8 activity and its pharmacological inhibition synergizes with melphalan, which could be beneficial to improve MM treatment in high-risk patients whatever their status for p53.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13148-021-01160-z.

del(17p) without TP53 mutation confers a poor prognosis in intensively treated newly diagnosed patients with multiple myeloma

Despite tremendous improvements in the outcome of patients with multiple myeloma in the past decade, high-risk patients have not benefited from the approval of novel drugs. The most important prognostic factor is the loss of parts of the short arm of chromosome 17, known as deletion 17p (del(17p)). A recent publication (on a small number of patients) suggested that these patients are at very high-risk only if del(17p) is associated with TP53 mutations, the so-called "double-hit" population. To validate this finding, we designed a much larger study on 121 patients presenting del(17p) in > 55% of their plasma cells, and homogeneously treated by an intensive approach. For these 121 patients, we performed deep next generation sequencing targeted on TP53. The outcome was then compared with a large control population (2505 patients lacking del(17p)). Our results confirmed that the "double hit" situation is the worst (median survival = 36 months), but that del(17p) alone also confers a poor outcome compared with the control cohort (median survival = 52.8 months vs 152.2 months, respectively). In conclusion, our study clearly confirms the extremely poor outcome of patients displaying "double hit," but also that del(17p) alone is still a very high-risk feature, confirming its value as a prognostic indicator for poor outcome.

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.

Multiple Myeloma, Version 3.2021, NCCN Clinical Practice Guidelines in Oncology

Multiple myeloma is a malignant neoplasm of plasma cells that accumulate in bone marrow, leading to bone destruction and marrow failure. This manuscript discusses the management of patients with solitary plasmacytoma, smoldering multiple myeloma, and newly diagnosed multiple myeloma.

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.

Genetic Basis of Extramedullary Plasmablastic Transformation of Multiple Myeloma

In patients with multiple myeloma, plasmablastic transformation in the bone marrow is rare and associated with poor outcomes. The significance of discordant extramedullary plasmablastic transformation in patients with small, mature clonal plasma cells in the bone marrow has not been well studied. Here, we report the clinicopathologic, cytogenetic, and molecular features of 10 such patients (male/female: 6/4, median age: 65 y, range: 48 to 76 y) with an established diagnosis of multiple myeloma in the bone marrow composed of small, mature plasma cells in parallel with a concurrent or subsequent extramedullary plasmablastic transformation. Eight patients with available survival data showed an overall aggressive clinical course with a median survival of 4.5 months after the diagnosis of extramedullary plasmablastic transformation, despite aggressive treatment and even in patients with low-level bone marrow involvement. Pathologically, the extramedullary plasmablastic myeloma were clonally related to the corresponding bone marrow plasma cells, showed high levels of CMYC and/or P53 expression with a high Ki-67 proliferation index by immunohistochemistry and harbored more complex genomic aberrations including frequent mutations in the RAS pathway and MYC rearrangements compared with their bone marrow counterparts. In summary, although genetic and immunohistochemical studies were not uniformly performed on all cases due to the retrospective nature of this study, our data suggest that discordant extramedullary plasmablastic transformation of multiple myeloma has an aggressive clinical course and is characterized by frequent mutations in the RAS pathway and more complex genomic abnormalities.

Risk Stratification in Multiple Myeloma in Indian Settings

Multiple myeloma (MM) constitutes 10% of all hematological malignancies. The last one decade has seen a phenomenal progress in the therapeutic options available for the management. Although it still remains incurable, with the advent of newer therapies, the median survival in many risk groups is now around 10 years. Conventional karyotyping of bone marrow samples has a positivity rate of 20-30% at diagnosis in patients of Multiple Myeloma. However, array Comparative Genomic Hybridisation (aCGH) has revealed that almost all MM patients have cytogenetic abnormalities which may affect the pathophysiology, selection of therapy and outcomes of the disease. The progress in the field of exploring the genetic landscape of multiple myeloma with multiple tools like Fluorescent in-situ hybridization, aCGH, Next Generation Sequencing, Flow cytometry, etc., combined with the traditional risk stratification markers like albumin, β2 microglobulin and LDH, is gradually leading towards a risk-adapted therapy. The recent R-ISS risk stratification has combined these two group of information to validate a prognostic score which is an improvement over the past tools like DSS and ISS. In view of the plethora of information available on the multitude of cytogenetic markers there is a tendency to evaluate for all of them at diagnosis, especially in research centers. This leads to a significant increase in the cost of therapy of Multiple Myeloma in day-to-day clinical practice and an increased out-of-pocket spending to the patient, especially in resource-limited settings like India. Also, there is a variable approach to pre-therapy cytogenetic evaluation and risk stratification at different Hematology centres in the country, often dictated by financial constraints and availability of specialized tests. This review discusses the risk stratification markers and tools available in MM in 2019 and how it can be adapted in the resource constraint settings so as to derive the maximum prognostic information from a minimal prognostic panel, as well as lead to standardization of the prognostic protocols in resource limited settings across various Hematology centres in India.

Acute myeloid leukemia or myelodysplastic syndrome with chromosome 17 abnormalities and long-term outcomes with or without hematopoietic stem cell transplantation

INTRODUCTION

Chromosome 17 abnormalities, especially disorders of the 17p region and including TP53 gene mutations, result in very low rates of cure for patients with acute myeloid leukemia (AML) or myelodysplastic syndrome (MDS) treated with conventional chemotherapy or allogeneic hematopoietic cell transplant (allo-HCT). Our retrospective study analyzed outcomes in patients with chromosome 17 (ch17) abnormalities who received conventional chemotherapy followed by allo-HCT versus those who did not receive a transplant. We analyzed whether poor outcomes extend to patients with all types of ch17 abnormalities and the impact of concomitant TP53 gene mutations assessed by next-generation sequencing (NGS) on prognosis.

METHODS

We retrospectively analyzed diagnostic and outcome data on 98 patients treated at our institution from 2012 to 2018 with AML or MDS who possessed ch17 abnormalities by cytogenetic analysis. The presence of TP53 mutations was analyzed by NGS. Primary endpoint of our study was overall survival (OS).

RESULTS

61 patients with AML and 37 with MDS were included. Complete remission (CR) with first line treatment was similar between induction chemotherapy or hypomethylating agents (HMA), 22.9 % versus 21.6 % (p = 0.33). Median OS for all patients (with or without transplant) was 10 months. Patients with abnormal ch17 in conjunction with any TP53 mutation(s) exhibited worse OS compared to patients without a TP53 mutation (10 versus 23 months, p = 0.02). 30 patients (19 AML, 11 MDS) underwent HCT, with a median OS of 11 months. For AML patients who underwent allo-HCT, 18 were in CR (13 with cytogenetic remission) and 1 had persistent disease at transplant. In the MDS cohort, 3 patients were in CR (2 with cytogenetic remission) and 8 had stable disease. Post allo-HCT survival of AML and MDS cohorts did not differ (p = 0.6), although cytogenetic CR at time of HCT trended towards improved OS (17 versus 8 months; p = 0.6).

CONCLUSIONS

AML/MDS patients with ch17 abnormalities have poor outcomes with or without HCT. Our results show that patients with ch17 abnormalities and TP53 mutations have a significantly poorer survival compared to patients who have ch17 abnormalities but no TP53 mutations. Drugs targeting abnormalities of the p53 pathway, improvement in depth of response prior to HCT, and novel maintenance strategies are needed for improved outcomes in these patients.

Promoter hypermethylation influences the suppressive role of long non-coding RNA MEG3 in the development of multiple myeloma

Methylation is a fundamental regulator of gene transcription. Long non-coding RNA maternally expressed 3 (MEG3) inhibits cell proliferation in various types of cancer. However, the molecular mechanisms of MEG3 methylation in the regulation of multiple myeloma (MM) are unknown. In the present study, MEG3 upregulation was negatively associated with the International Staging System (ISS) status of the bone marrow samples of 39 patients with MM. MEG3 overexpression in an MM cell line resulted in elevated p53 expression. Furthermore, the results of methylation-specific PCR revealed that the abnormal methylation status of the MEG3 promoter region was present in eight of the 39 bone marrow samples collected. Treatment of the MM cell line with the DNA methylation inhibitor 5-Aza-2'-deoxycytidine (5-Aza-CdR) resulted in tumor cell proliferation inhibition, apoptosis induction and G₀/G₁ cell cycle arrest. Furthermore, 5-Aza-CdR decreased aberrant hypermethylation of the MEG3 promoter and increased the expression of MEG3. However, 5-Aza-CdR exerted no effect on p53 expression. To the best of our knowledge, the present study is the first to report that the demethylation reagent 5-Aza-CdR may serve as a therapeutic agent in MM by upregulating MEG3 expression. However, the mechanism of action was independent of p53 expression.

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 deubiquitinase USP7 stabilizes Maf proteins to promote myeloma cell survival

The Maf proteins, including c-Maf, MafA, and MafB, are critical transcription factors in myelomagenesis. Previous studies demonstrated that Maf proteins are processed by the ubiquitin-proteasome pathway, but the mechanisms remain elusive. This study applied MS to identify MafB ubiquitination-associated proteins and found that the ubiquitin-specific protease USP7 was present in the MafB interactome. Moreover, USP7 also interacted with c-Maf and MafA and blocked their polyubiquitination and degradation. Consistently, knockdown of USP7 resulted in Maf protein degradation along with increased polyubiquitination levels. The action of USP7 thus promoted Maf transcriptional activity as evidenced by luciferase assays and by the up-regulation of the expression of Maf-modulated genes. Furthermore, USP7 was up-regulated in myeloma cells, and it was negatively associated with the survival of myeloma patients. USP7 promoted myeloma cell survival, and when it was inhibited by its specific inhibitor P5091, myeloma cell lines underwent apoptosis. These results therefore demonstrated that USP7 is a deubiquitinase of Maf proteins and promotes MM cell survival in association with Maf stability. Given the significance of USP7 and Maf proteins in myeloma genesis, targeting the USP7/Maf axle is a potential strategy to the precision therapy of MM.

1q21 Gain Combined with High-Risk Factors Is a Heterogeneous Prognostic Factor in Newly Diagnosed Multiple Myeloma: A Multicenter Study in China

The identification of prognostic factors for multiple myeloma is important. This article focuses on the prognostic value of 1q21 gain in a Chinese population according to different treatment regimens and accompanying high‐risk factors.

Background.

The prognostic value of 1q21 gain in newly diagnosed multiple myeloma (NDMM) remains controversial. Our aim was to investigate the prognostic value of 1q21 gain in a Chinese population.

Materials and Methods.

We retrospectively identified 565 patients with NDMM from multiple centers in China.

Results.

We detected 1q21 gain in 222 (39.3%) patients, among whom 144 had three copies of 1q21, 57 had four copies of 1q21, and 21 had at least five copies of 1q21. Copy number variation did not show any effect on the disease outcome. Multivariate analysis indicated that 1q21 gain was an independent factor for poor prognosis, but we found that 1q21 gain was strongly associated with other high‐risk factors, such as del(17p), t(4;14), t(14;16), lactate dehydrogenase (LDH) level >300 U/L and International Scoring System (ISS) stage II–III (p < .001). Further analysis revealed that in the absence of other high‐risk factors, isolated 1q21 gain resulted in similar progression‐free survival (PFS; 52.0 vs. 52.8 months, p = .810) and overall survival (OS; not reached vs. not reached, p = .833); additionally, when present with other high‐risk cytogenetic abnormalities or increased LDH levels, 1q21 gain lost its prognostic power. However, the presence of 1q21 gain increased the adverse impact of ISS stage. Furthermore, 1q21 gain predicted poor PFS and OS in patients who received bortezomib‐based regimens. Moreover, autologous stem cell transplantation reversed the poor prognosis in patients with 1q21 gain.

Conclusion.

Our results show that heterogeneity exists among patients with 1q21 gain and suggest that we should assess the impact of 1q21 gain on prognosis according to different treatment regimens and accompanying high‐risk factors.

Implications for Practice.

1q21 gain is one of the most common chromosomal aberrations in multiple myeloma (MM); however, the prognostic value of 1q21 gain remains controversial. This study investigated the prognostic value of 1q21 gain in a Chinese population with newly diagnosed MM. The results showed that heterogeneity exists among patients with 1q21 gain and suggested that the impact of 1q21 gain on prognosis should be assessed according to different treatment regimens and accompanying high‐risk factors. These results could help stratify risk in patients with MM and guide treatment decisions.

Natural history of multiple myeloma with de novo del(17p)

We compared the outcomes of 310 patients with newly diagnosed multiple myeloma with del(17p) detected by FISH to patients with high-risk translocations (HRT) (n = 79) and standard-risk (SR) cytogenetics (n = 541). The median progression-free survival (PFS) following initial therapy for the three groups was 21.1, 22, and 30.1 months, respectively (P = 0.437- del(17p) vs. HRT); the median overall survival (OS) was 47.3, 79.1, and 109.8 months, respectively, (P = 0.007- del(17p) vs. HRT). PFS and OS for patients with relative loss of 17p (n = 21) were comparable to other patients with del(17p). The PFS was similar between the del(17p) and HRT groups when stratified for age, ISS stage or treatment. The OS of del(17p) and HRT groups were similar in presence of advanced age, ISS III stage or if patients did not receive a proteasome-inhibitor containing induction. ISS III stage, high LDH and HRT, but not the percentage of cells with del(17p) predicted shorter OS in patients with del(17p). The median OS for low (ISS I, normal LDH and no HRT), intermediate (neither low nor high-risk) and high-risk (ISS III and either elevated LDH or coexistent HRT) groups among del(17p) patients were 96.2, 45.4, and 22.8 months, respectively, allowing further risk stratification.

High-risk myeloma and minimal residual disease postautologous-HSCT predict worse outcomes

The aim of our study was to determine the impact of high-risk disease (HRD) and MRD on outcomes in myeloma patients receiving bortezomib-based induction followed by autologous hematopoietic stem cell transplant (auto-HSCT). HRD included t(4:14), t(14;16), del 17p, del 1p and/or amplification 1q by cytogenetics/FISH; all others were standard-risk disease (SRD). A subset of 165 newly diagnosed myeloma patients in a 2:1 ratio of HRD:SRD was generated using propensity score based nearest neighbor matching. Multiparametric flow cytometry (MFC) was used to detect MRD after auto-HSCT in select patients. MRD+ status at 3 months post auto-HSCT (hazard ratio (HR = 4.23, p = .028) and HRD (HR = 1.72, p = .026) were associated with a shorter PFS. Similarly, MRD+ 3 months post auto-HSCT (HR = 6.93, p = .08) and HRD (HR = 3.54, p < .001) and were associated with a shorter OS. Despite bortezomib-based induction, upfront auto-HSCT, and use of maintenance therapy, PFS and OS remained worse in MRD+ and HRD patients.

Deregulation and Targeting of TP53 Pathway in Multiple Myeloma

Multiple Myeloma (MM) is an incurable disease characterized by a clonal evolution across the course of the diseases and multiple lines of treatment. Among genomic drivers of the disease, alterations of the tumor suppressor TP53 are associated with poor outcomes. In physiological situation, once activated by oncogenic stress or DNA damage, p53 induces either cell-cycle arrest or apoptosis depending on the cellular context. Its inactivation participates to drug resistance in MM. The frequency of TP53 alterations increases along with the progression of the disease, from 5 at diagnosis to 75% at late relapses. Multiple mechanisms of regulation lead to decreased expression of p53, such as deletion 17p, TP53 mutations, specific microRNAs overexpression, TP53 promoter methylations, and MDM2 overexpression. Several therapeutic approaches aim to target the p53 pathway, either by blocking its interaction with MDM2 or by restoring the function of the altered protein. In this review, we describe the mechanism of deregulation of TP53 in MM, its role in MM progression, and the therapeutic options to interact with the TP53 pathway.

Risk Stratification and Targets in Multiple Myeloma: From Genomics to the Bedside

In the past 15 years, significant improvements in overall survival have been observed in multiple myeloma (MM), mainly due to the availability of novel drugs with variable mechanisms of action. However, these improvements do not benefit all patients, and some of them, defined as high risk, still display short survival. The most important risk factors are the genetic abnormalities present in the malignant plasma cells. The most important high-risk features are the del(17p), the del(1p32), the t(4;14), and 1q gains. Assessing these markers is mandatory at diagnosis and at least at first relapse, since it has been clearly shown that the lenalidomide-dexamethasone combination is not efficient in these high-risk patients. In contrast, a triplet combination adding a proteasome inhibitor or a monoclonal antibody to the lenalidomide-dexamethasone backbone clearly improves the survival. Another way to improve the outcome would be to specifically target genetic abnormalities with specific inhibitors. The sequencing of more than 1,000 MM exomes revealed again a huge heterogeneity. The most frequent mutations involve the KRAS and NRAS genes (20%-25% each). However, to date, no good RAS-inhibitors are clinically available, preventing targeted therapy. The only drugable target is the V600E BRAF mutation. Unfortunately, this specific mutation is present in only 3% of the patients. Finally, it has been recently reported a specific efficiency of the BCL2-inhibitor venetoclax in patients with the t(11;14) translocation, which is found in 20% of the patients.

MicroRNA-324-5p suppresses the migration and invasion of MM cells by inhibiting the SCFβ-TrCP E3 ligase

Multiple myeloma (MM) is a cytogenetically heterogeneous malignancy of plasma cells in bone marrow. Among the cytogenetic abnormalities of MM, del(17p) is a well-recognized high-risk genetic lesion associated with the late stage and progression of the disease. MicroRNA (miR)-324-5p, located at 17p13.1, was identified to be involved in the dysregulation of a number of types of malignant disease. However, whether miR-324-5p is associated with the development and progression of MM remains unknown. In the present study, the expression status of miR-324-5p in MM, and its effect on the migratory and invasive ability of MM cells were investigated. Using ubiquitination pathway polymerase chain reaction array, the inhibitory effect of miR-324-5p on the ubiquitinated proteins was investigated. It was identified that miR-324-5p levels were decreased in samples from patients with MM and MM cell lines. Increased expression of miR-324-5p by transfection of miR-324-5p mimic suppressed the proliferative, migratory and invasive abilities of MM.1R cells. Furthermore, increased expression of miR-324-5p in MM.1R cells inhibited the ubiquitination pathway and decreased the levels of ubiquitination-associated proteins, particularly the Skp1-Cullin1-F-box β-transducin repeat-containing protein (SCF^β-TrCP) E3 ligase. In addition, the results of the present study demonstrated that the SCF^β-TrCP E3 ligase may contribute to the suppression of MM cell motility by inhibiting the expression of metastasis-associated genes, including metastasis suppressor 1. In conclusion, the results of the present study suggested that miR-324-5p may act as a tumor suppressor by impairing the motility of MM cells by suppressing the ubiquitination pathway.

Destabilizing NEK2 overcomes resistance to proteasome inhibition in multiple myeloma

Drug resistance remains the key problem in cancer treatment. It is now accepted that each myeloma patient harbors multiple subclones and subclone dominance may change over time. The coexistence of multiple subclones with high or low chromosomal instability (CIN) signature causes heterogeneity and drug resistance with consequent disease relapse. In this study, using a tandem affinity purification-mass spectrometry (TAP-MS) technique, we found that NEK2, a CIN gene, was bound to the deubiquitinase USP7. Binding to USP7 prevented NEK2 ubiquitination resulting in NEK2 stabilization. Increased NEK2 kinase levels activated the canonical NF-κB signaling pathway through the PP1α/AKT axis. Newly diagnosed myeloma patients with activated NF-κB signaling through increased NEK2 activity had poorer event-free and overall survivals based on multiple independent clinical cohorts. We also found that NEK2 activated heparanase, a secreted enzyme, responsible for bone destruction in an NF-κB-dependent manner. Intriguingly, both NEK2 and USP7 inhibitors showed great efficacy in inhibiting myeloma cell growth and overcoming NEK2-induced and -acquired drug resistance in xenograft myeloma mouse models.

PRIMA-1 targets the vulnerability of multiple myeloma of deregulated protein homeostasis through the perturbation of ER stress via p73 demethylation

Despite therapeutic advancement, multiple myeloma (MM) remains incurable with drug resistance being one of the main challenges in the clinic. Myeloma cells possess high protein secretory load, leading to increased intracellular endoplasmic reticulum (ER) stress. Hence, they are vulnerable to further perturbation to its protein homeostasis. In studying the therapeutic mechanism of PRIMA-1 (mutant-p53-reactivating-agent), we uncovered its novel p53-independent-mechanism that can be exploited for myeloma. Despite its inability in restoring the wild type-p53 protein conformation and transcriptional function in the mutant-p53-human-myeloma-cells, PRIMA-1 was efficacious against myeloma cells with differential p53 genotypes. Strikingly, cells without p53 expression demonstrated highest drug sensitivity. Genome-wide gene-expression analysis revealed the involvement of ER stress/UPR-pathway in inducing PRIMA-1-toxicity. UPR markers, HSP70, CHOP and GADD34, were significantly up-regulated, concomitantly with the induction of apoptosis. Furthermore, there was a global attenuation of protein synthesis, correlated with phospho-eIF2a up-regulation. Mechanistically, we identified that PRIMA-1 could cause the demethylation of TP73, through DNMT1 depletion, to subsequently enhance UPR. Of clinical significance, we observed that PRIMA-1 had additive therapeutic effects with another UPR-inducing-agent, bortezomib. Importantly, it can partially re-sensitize bortezomib-resistant cells to bortezomib. Given that MM is already stressed at the baseline in the ER, our results implicated that PRIMA-1 is a potential therapeutic option in MM by targeting its Achilles heel.

Successful Autologous Hematopoietic Stem Cell Transplantation Followed by Bortezomib Maintenance in a Patient with Relapsed CD138-low Multiple Solitary Plasmacytomas Harboring a 17p Deletion

Solitary bone plasmacytoma (SBP) tends to progress to multiple myeloma (MM); however, progression to multiple solitary plasmacytomas (MSP) is rare. We report a case of CD138-low MSP with 17p deletion in a patient with relapsed SBP. 17p deletion is associated with a poor outcome in patients with MM, and the low expression of CD138 in myeloma cells is associated with drug resistance and a poor prognosis. The patient was successfully treated with bortezomib plus dexamethasone induction therapy and autologous hematopoietic stem cell transplantation followed by bortezomib maintenance therapy. Consequently, bortezomib treatment was stopped and a stringent complete response has been maintained.

Clinical implications of cytogenetic heterogeneity in multiple myeloma patients with TP53 deletion

TP53 deletion (ΔTP53) in myeloma is known to be a high-risk finding associated with poorer prognosis. The prognostic impact of underlying cytogenetic heterogeneity in patients with myeloma associated with ΔTP53 is unknown. We studied 90 patients with myeloma associated with ΔTP53 identified by interphase fluorescence in situ hybridization and assessed the impact of karyotype and coexisting alterations of IGH, RB1, and CKS1B. There were 54 men and 36 women with a median age of 59 years (range 38-84); 14 patients had a normal karyotype (NK/ΔTP53), 73 had a complex karyotype (CK/ΔTP53), and 3 had a non-complex abnormal karyotype. Patients with CK/ΔTP53 showed a significantly poorer overall survival compared with patients with NK/ΔTP53 (P=0.0243). Furthermore, in the CK/ΔTP53 group, patients with IGH rearrangement other than t(11;14)(q13;q32)/CCND1-IGH, designated as adverse-IGH, had an even worse outcome (P=0.0045). In contrast, RB1 deletion, CKS1B gain, ploidy, additional chromosome 17 abnormalities, or ΔTP53 clone size did not impact prognosis. Stem cell transplant did not improve overall survival in either the NK/ΔTP53 or CK/ΔTP53 (P=0.8810 and P=0.1006) groups, but tandem stem cell transplant did improve the overall survival of patients with CK/ΔTP53 (P=0.0067). Multivariate analysis confirmed in this cohort that complex karyotype (hazard ratio 1.976, 95% CI 1.022-3.821, P=0.043), adverse-IGH (hazard ratio 3.126, 95% CI 1.192-8.196, P=0.020), and tandem stem cell transplant independently correlate with overall survival (hazard ratio 0.281, 95% CI 0.091-0.866, P=0.027). We conclude that comprehensive genetic assessment adds to TP53 status in the risk stratification of myeloma patients.

Small molecule CP-31398 induces reactive oxygen species-dependent apoptosis in human multiple myeloma

Reactive oxygen species (ROS) are normal byproducts of a wide variety of cellular processes. ROS have dual functional roles in cancer cell pathophysiology. At low to moderate levels, ROS act as signaling transducers to activate cell proliferation, migration, invasion, and angiogenesis. In contrast, high levels of ROS induce cell death. In multiple myeloma (MM), ROS overproduction is the trigger for apoptosis induced by several anticancer compounds, including proteasome inhibitors. However, no drugs for which oxidative stress is the main mechanism of action are currently used for treatment of MM in clinical situations. In this study, we demonstrate that the p53-activating small molecule CP-31398 (CP) effectively inhibits the growth of MM cell lines and primary MM isolates from patients. CP also suppresses the growth of MM xenografts in mice. Mechanistically, CP was found to induce intrinsic apoptosis in MM cells via increasing ROS production. Interestingly, CP-induced apoptosis occurs regardless of the p53 status, suggesting that CP has additional mechanisms of action. Our findings thus indicate that CP could be an attractive candidate for treatment of MM patients harboring p53 abnormalities; this satisfies an unmet clinical need, as such individuals currently have a poor prognosis.

The novel autophagy inhibitor elaiophylin exerts antitumor activity against multiple myeloma with mutant TP53 in part through endoplasmic reticulum stress-induced apoptosis

Elaiophylin is a natural compound and a novel and potent inhibitor of late stage autophagy with outstanding antitumor activity in human ovarian cancer cells. However, the possible biologic effects and functional linkage between elaiophylin and multiple myeloma (MM) have not been explored. This study aimed to assess the effect of elaiophylin on MM cells with mutant TP53 and the possible molecular mechanism. The results suggested that elaiophylin exerted anti-myeloma activity by inducing apoptosis and proliferation arrest. As expected, elaiophylin blocked autophagy flux in MM cells. Subsequently, persistent activation of endoplasmic reticulum (ER) stress was induced. Moreover, the apoptotic effect was to some extent attenuated by the ER stress inhibitor tauroursodeoxycholic acid (TUDCA). Further studies indicated that elaiophylin effectively suppressed MM cell growth without obvious side effects in zebrafish embryo and mouse xenograft models. Taken together, our data are the first to demonstrate that exposure of human MM cells with mutant TP53 to elaiophylin blocked autophagy flux and thus induced cell death, which partially involved ER stress-associated apoptosis. Targeted disruption of the cellular protein handling system by elaiophylin is therefore a promising therapeutic strategy for overcoming incurable MM, even when TP53 mutations are present.

Identification and expression of MMSA-8, and its clinical significance in multiple myeloma

In our previous studies, we identified 12 multiple myeloma (MM)-associated antigens by serological analysis of tumor-associated antigens with a recombinant cDNA expression library (SEREX) on MM. MM-associated antigen-8 (MMSA-8) was one of the new antigens identified. We determined the 3′- and 5′-ends of MMSA-8 using SMART-rapid amplification of cDNA ends (RACE) and then cloned its full-length cDNA in the U266 cell line. The full cDNA sequence revealed that MMSA-8 is RPS27A-related transcript variant 1 that is specifically associated with MM. We examined its prognostic significance for the first time, by investigating the correlations between MMSA-8 expression and definite clinicopathological features. We quantitatively assessed MMSA-8 expression using qRT-PCR and western blot analysis in healthy donors and MM patients. The expression levels of MMSA-8 were upregulated with statistical significance in MM patients in contrast to those in healthy donors. The expression of MMSA-8 was also upregulated in relapsed patients compared with that in the complete remission (CR) group. Contrasting MMSA-8 expression levels in different patients with definite clinicopathological features suggested an association between MMSA-8 with unfavorable clinicopathological characteristics, such as international staging system (ISS) stage III, higher lactate dehydrogenase (LDH) levels and higher C-reactive protein (CRP) levels. The expression of MMSA-8 was also increased in patients with unfavorable cytogenetic and genetic abnormalities, including the presence of t(11;14), t(4;14), t(14;16), del(17p), del(13q) and p53 deletion, which was statistically significant. The expression of MMSA-8 exhibited significant variance in the treatment responses of the CR, PR, progression and relapse groups. Univariate and multivariate analyses revealed that high MMSA-8 values were associated with poorer progression-free survival (PFS) and overall survival (OS) in MM patients independently. In conclusion, our data indicated that MMSA-8 is an independent and unfavorable prognostic risk factor in MM; MMSA-8 is also a promising diagnostic and therapeutic target in MM patients, but further validation is needed.

Genomics of Multiple Myeloma

Multiple myeloma (MM) is characterized by wide variability in the chromosomal/genetic changes present in tumor plasma cells. Genetically, MM can be divided into two groups according to ploidy and hyperdiploidy versus nonhyperdiploidy. Several studies in gene expression profiling attempted to identify subentities in MM without convincing results. These studies mostly confirmed the cytogenetic data and subclassified patients according to 14q32 translocations and ploidy. More-recent data that are based on whole-exome sequencing have confirmed this heterogeneity and show many gene mutations but without a unifying mutation. These newer studies have shown the frequent alteration of the mitogen-activated protein kinase pathway. The most interesting data have demonstrated subclonality in all patients with MM, including subclonal mutations of supposed driver genes KRAS, NRAS, and BRAF.

The Evolution of Prognostic Factors in Multiple Myeloma

Multiple myeloma (MM) is a heterogeneous hematologic malignancy involving the proliferation of plasma cells derived by different genetic events contributing to the development, progression, and prognosis of this disease. Despite improvement in treatment strategies of MM over the last decade, the disease remains incurable. All efforts are currently focused on understanding the prognostic markers of the disease hoping to incorporate the new therapeutic modalities to convert the disease into curable one. We present this comprehensive review to summarize the current standard prognostic markers used in MM along with novel techniques that are still in development and highlight their implications in current clinical practice.

MicroRNA expression patterns and target prediction in multiple myeloma development and malignancy

Epigenetic changes have emerged as key causes in the development and progression of multiple myeloma (MM). In this study, global microRNA (miRNA) expression profiling were performed for 27 MM (19 specimens and 8 cell lines) and 3 normal controls by microarray. miRNA-targets were identified by integrating the miRNA expression profiles with mRNA expression profiles of the matched samples (unpublished data). Two miRNAs were selected for verification by RT-qPCR (miR-150-5p and miR-4430). A total of 1791 and 8 miRNAs were over-expressed and under-expressed, respectively in MM compared to the controls (fold change ≥2.0; p < 0.05). The miRNA-mRNA integrative analysis revealed inverse correlation between 5 putative target genes (RAD54L, CCNA2, CYSLTR2, RASGRF2 and HKDC1) and 15 miRNAs (p < 0.05). Most of the differentially expressed miRNAs are involved in survival, proliferation, migration, invasion and drug resistance in MM. Some have never been described in association with MM (miR-33a, miR-9 and miR-211). Interestingly, our results revealed 2 miRNAs, which are closely related to B cell differentiation (miR-150 and miR-125b). For the first time, we suggest that miR-150 might be potential negative regulator for two critical cell cycle control genes, RAD54L and CCNA2, whereas miR-125b potentially target RAS and CysLT signaling proteins, namely RASGRF2 and CYSLTR2, respectively. This study has enhanced our understanding on the pathobiology of MM and opens up new avenues for future research in myelomagenesis.

Maintenance versus Induction Therapy Choice on Outcomes after Autologous Transplantation for Multiple Myeloma

Bortezomib (V), lenalidomide (R), cyclophosphamide (C), and dexamethasone (D) are components of the most commonly used modern doublet (RD, VD) or triplet (VRD, CVD) initial induction regimens before autologous hematopoietic cell transplantation (AHCT) for multiple myeloma (MM) in the United States. In this study we evaluated 693 patients receiving "upfront" AHCT after initial induction therapy with modern doublet or triplet regimens using data reported to the Center for International Blood and Marrow Transplant Research from 2008 to 2013. Analysis was limited to those receiving a single AHCT after 1 line of induction therapy within 12 months from treatment initiation for MM. In multivariate analysis, progression-free survival (PFS) and overall survival were similar irrespective of induction regimen. However, high-risk cytogenetics and nonreceipt of post-transplant maintenance/consolidation therapy were associated with higher risk of relapse. Patients receiving post-transplant therapy had significantly improved 3-year PFS versus no post-transplant therapy (55% versus 39%, P = .0001). This benefit was most evident in patients not achieving at least a complete response post-AHCT (P = .005). In patients receiving upfront AHCT, the choice of induction regimen (doublet or triplet therapies) appears to be of lower impact than use of post-transplant therapy.

Molecular Mechanisms of p53 Deregulation in Cancer: An Overview in Multiple Myeloma

The p53 pathway is inactivated in the majority of human cancers. Although this perturbation frequently occurs through the mutation or deletion of p53 itself, there are other mechanisms that can attenuate the pathway and contribute to tumorigenesis. For example, overexpression of important p53 negative regulators, such as murine double minute 2 (MDM2) or murine double minute 4 (MDM4), epigenetic deregulation, or even alterations in TP53 mRNA splicing. In this work, we will review the different mechanisms of p53 pathway inhibition in cancer with special focus on multiple myeloma (MM), the second most common hematological malignancy, with low incidence of p53 mutations/deletions but growing evidence of indirect p53 pathway deregulation. Translational implications for MM and cancer prognosis and treatment are also reviewed.

Concomitant MDS with isolated 5q deletion and MGUS: case report and review of molecular aspects

Patients with monoclonal gammopathy of undetermined significance (MGUS) have a higher risk for the development of concomitant primary cancers such as multiple myeloma (MM) and myelodysplastic syndrome (MDS). We report the case of patient initially suffering from MGUS of the IgG lambda subtype for more than 10 yr, which evolved to MM and MDS with deletion (5q) with severe pancytopenia. Due to pancytopenia, he received dose-reduced treatment with lenalidomide and dexamethasone. He achieved an ongoing transfusion independency after about 1 month of treatment. Bone marrow taken 14 months after start of treatment showed a complete cytogenetic response of the del(5q) clone and a plasma cell infiltration below 5%. In contrast to the development of MM in MGUS patients, the subsequent occurrence of MDS after diagnosis of MGUS is infrequent. Moreover, the biological association of MDS with MGUS is not sufficiently understood, but the non-treatment-related occurrence supports the pathogenetic role of pre-existing alterations of stem cells. Here, we summarize data on concomitant MDS and MGUS/MM with particular emphasis on molecular aspects.

Baseline characteristics, chromosomal alterations, and treatment affecting prognosis of deletion 17p in newly diagnosed myeloma

Deletion 17p13, del(17p), is associated with poor outcome in myeloma but some patients show long-term survival. With the current study we intended to identify factors impacting outcome of such high risk patients. We analyzed 110 newly diagnosed, symptomatic patients with del(17p) detected by fluorescence in situ hybridization (FISH) in CD138-purified myeloma cells to identify prognostic factors for survival. Age >65 years, ISS III, and elevated LDH negatively impacted survival. Patients with subclonal (10-60% of plasma cells) del(17p) had longer progression-free survival (PFS) than patients with del(17p) in >60% of plasma cells (26 vs. 19 months, P = 0.03). Additional gain of 1q21 was associated with shorter PFS (17 vs. 25 months, P = 0.01). Hyperdiploidy did not ameliorate impact of del(17p), but gain 19q13 predicted longer PFS (30 vs. 18 months, P = 0.01) and overall survival (50 vs. 29 months, P = 0.01). Multivariate analysis in transplant eligible patients (≤65 years) revealed better survival for patients treated with upfront autologous transplantation (hazard ratio, [95% confidence interval]: 0.15 [0.04, 0.58], P = 0.006). Application of maintenance therapy was associated with better survival in transplant-eligible patients (0.30 [0.09, 0.99], P = 0.05). We demonstrate heterogeneous outcome of patients with del(17p) according to baseline characteristics and treatment. 19q13 should be included in routine FISH panel, since gains were associated with better survival. Am. J. Hematol. 91:E473-E477, 2016. © 2016 Wiley Periodicals, Inc.

Outcomes in patients with multiple myeloma with TP53 deletion after autologous hematopoietic stem cell transplant

TP53 gene deletion is associated with poor outcomes in multiple myeloma (MM). We report the outcomes of patients with MM with and without TP53 deletion who underwent immunomodulatory drug (IMiD) and/or proteasome inhibitor (PI) induction followed by autologous hematopoietic stem cell transplant (auto-HCT). We identified 34 patients with MM and TP53 deletion who underwent IMiD and/or PI induction followed by auto-HCT at our institution during 2008-2014. We compared their outcomes with those of control patients (n = 111) with MM without TP53 deletion. Median age at auto-HCT was 59 years in the TP53-deletion group and 58 years in the control group (P = 0.4). Twenty-one patients (62%) with TP53 deletion and 69 controls (62%) achieved at least partial remission before auto-HCT (P = 0.97). Twenty-three patients (68%) with TP53 deletion and 47 controls (42%) had relapsed disease at auto-HCT (P = 0.01). Median progression-free survival was 8 months for patients with TP53 deletion and 28 months for controls (P < 0.001). Median overall survival was 21 months for patients with TP53 deletion and 56 months for controls (P < 0.001). On multivariate analysis of both groups, TP53 deletion (hazard ratio 3.4, 95% confidence interval 1.9-5.8, P < 0.001) and relapsed disease at auto-HCT (hazard ratio 2.0, 95% confidence interval 1.2-3.4, P = 0.008) were associated with a higher risk of earlier progression. In MM patients treated with PI and/or IMiD drugs, and auto-HCT, TP53 deletion and relapsed disease at the time of auto-HCT are independent predictors of progression. Novel approaches should be evaluated in this high-risk population. Am. J. Hematol. 91:E442-E447, 2016. © 2016 Wiley Periodicals, Inc.