Transcriptional dysregulation of the deleted in colorectal carcinoma gene in multiple myeloma and monoclonal gammopathy of undetermined significance

Establishment and Characteristics of a Novel Mantle Cell Lymphoma-derived Cell Line and a Bendamustine-resistant Subline

BACKGROUND/AIM

Bendamustine hydrochloride (BH) is a key therapeutic agent for mantle cell lymphoma (MCL), while the mechanism underlying BH-resistance has not been verified.

MATERIALS AND METHODS

We compared molecular/biological characteristics of a newly-generated MCL-derived cell line KPUM-YY1 and its BH-resistant subline KPUM-YY1R.

RESULTS

The growth-inhibitory IC₅₀ for BH was 20 μM in KPUM-YY1 cells, while cell proliferation was not inhibited by up to 60 μM BH in KPUM-YY1R cells. Compared to KPUM-YY1 cells, gene expression profiling in KPUM-YY1R cells revealed up-regulation of 312 genes, including ABCB1 encoding P-glycoprotein (P-gp), and microsomal glutathione S-transferase 1 (MGST1). Addition of either a P-gp inhibitor or a GST inhibitor, at least partly, restored sensitivity to BH in KPUM-YY1R cells. In addition, KPUM-YY1R cells showed cross-resistance against various anti-MCL chemotherapeutics.

CONCLUSION

BH resistance is mediated by overlapping mechanisms with overexpression of ABCB1 and MGST1, and is potentially accompanied by multidrug resistance in MCL.

Prognostic Biomarkers in the Progression From MGUS to Multiple Myeloma: A Systematic Review

Multiple myeloma (MM), characterized by malignant plasma cells in the bone marrow, is consistently preceded by asymptomatic premalignant stage monoclonal gammopathy of undetermined significance (MGUS). These MGUS patients have an annual risk of 1% to progress to MM. Clinical, imaging, and genomic (genetic and epigenetic) factors were identified, whose presence increased the risk of progression from MGUS to MM. In this systematic review we summarize the currently identified clinical, imaging, and genomic biomarkers suggested to increase the progression risk or shown to be differentially expressed/present between both cohorts of patients. Despite the wide range of proposed markers, there are still no reliable biomarkers to individually predict which MGUS patient will progress to MM and which will not. Research on biomarkers in the progression from MGUS to MM will give more insight in the unknown pathogenesis of this hematological malignancy. This would improve research by elucidating new pathways and potential therapeutic targets as well as clinical management by closer follow-up and earlier treatment of high-risk MGUS patients.

STAT3-induced long noncoding RNAs in multiple myeloma cells display different properties in cancer

Interleukin-6 (IL-6)-activated Signal Transducer and Activator of Transcription 3 (STAT3) facilitates survival in the multiple myeloma cell line INA-6 and therefore represents an oncogenic key player. However, the biological mechanisms are still not fully understood. In previous studies we identified microRNA-21 as a STAT3 target gene with strong anti-apoptotic potential, suggesting that noncoding RNAs have an impact on the pathogenesis of human multiple myeloma. Here, we describe five long noncoding RNAs (lncRNAs) induced by IL-6-activated STAT3, which we named STAiRs. While STAiRs 1, 2 and 6 remain unprocessed in the nucleus and show myeloma-specific expression, STAiRs 15 and 18 are spliced and broadly expressed. Especially STAiR2 and STAiR18 are promising candidates. STAiR2 originates from the first intron of a tumor suppressor gene. Our data support a mutually exclusive expression of either STAiR2 or the functional tumor suppressor in INA-6 cells and thus a contribution of STAiR2 to tumorigenesis. Furthermore, STAiR18 was shown to be overexpressed in every tested tumor entity, indicating its global role in tumor pathogenesis. Taken together, our study reveals a number of STAT3-induced lncRNAs suggesting that the interplay between the coding and noncoding worlds represents a fundamental principle of STAT3-driven cancer development in multiple myeloma and beyond.

Utilizing next-generation sequencing in the management of multiple myeloma

INTRODUCTION

Multiple myeloma (MM) is a bone marrow plasma cell malignancy characterized by wide clinical presentation and heterogeneous genetic background. Despite the recent advances in patient outcome, new markers are needed for improving risk prediction and choice of a more appropriate therapy. In this perspective, the genetic makeup of MM cells is being better characterized by means of next-generation sequencing (NGS) technologies. Areas covered: The authors discuss how the application of NGS has improved our knowledge of MM biology by discovering its mutational landscape, identifying the operating mutational processes, and revealing the clonal composition of tumors and the dynamics of its evolution; and how this can have important clinical implications in terms of prognostication, therapeutic choices, and response assessment. Finally, the authors provide a quick outlook of future applications of these technologies that could help in the management of the disease in the next years. Expert commentary: The clinical exploitation of NGS-based characterization of MM patients has as its ultimate goal the precision medicine. Considerable obstacles to its implementation in myeloma management exist; therefore, the concerted effort of all involved stakeholders is mandatory to ensure that it will become a reality in routine clinical practice in the next future.

Gene Expression Profiles in Myeloma: Ready for the Real World?

Multiple myeloma is a plasma cell malignancy characterized by molecular and clinical heterogeneity. The outcome of the disease has been dramatically improved with the advent of new drugs in the past few years. However, even in this context of increasing therapeutic options, important challenges remain, such as accurately evaluating patients' prognosis and predicting sensitivity to specific treatments and drug combinations. Transcriptomic studies have largely contributed to help decipher multiple myeloma complexity, characterizing multiple myeloma subgroups distinguished by different outcomes. Microarrays and, more recently, RNA sequencing allow evaluation of expression of coding and noncoding genes, alternate splicing events, mutations, and novel transcriptome modifiers, providing new information regarding myeloma biology, prognostication, and therapy. In this review, we discuss the role and impact of gene expression profiling studies in myeloma. Clin Cancer Res; 22(22); 5434-42. ©2016 AACR SEE ALL ARTICLES IN THIS CCR FOCUS SECTION, "MULTIPLE MYELOMA MULTIPLYING THERAPIES".