A multiple myeloma-specific capture sequencing platform discovers novel translocations and frequent, risk-associated point mutations in IGLL5

IGLL5 controlled by super-enhancer affects cell survival and MYC expression in mature B-cell lymphoma

IGLL5 is shown to be located near super-enhancer (SE) in B-cell tumors, and this gene is frequently mutated and a target of translocation in B-cell tumors. These results suggest roles of the IGLL5 in tumorigenesis; however, its functional properties have been unclear. We found that two mature B-cell lymphoma cell lines expressed IGLL5 mRNA with Cλ1 segment. JQ1 treatment resulted in down-expression of IGLL5, indicating that IGLL5 is controlled by SE. IGLL5 knockdown induced cell death with down-expression of MYC. Our results suggested that IGLL5 might have a role in survival of mature B-cell tumors and involvement in MYC expression. (100 words).

Transcriptomic analysis of mRNAs in human whole blood identified age-specific changes in healthy individuals

Older age is one of the most important shared risk factors for multiple chronic diseases, increasing the medical burden to contemporary societies. Current research focuses on identifying aging biomarkers to predict aging trajectories and developing interventions aimed at preventing and delaying the progression of multimorbidity with aging. Here, a transcriptomic changes analysis of whole blood genes with age was conducted. The age-related whole blood gene-expression profiling datasets were downloaded from the Gene Expression Omnibus (GEO) database. We screened the differentially expressed genes (DEGs) between healthy young and old individuals and performed functional enrichment analysis. Cytoscape with Cytohubba and MCODE was used to perform an interaction network of DEGs and identify hub genes. In addition, ROC curves and correlation analysis were used to evaluate the accuracy of hub genes. In total, we identified 29 DEGs between young and old samples that were enriched mainly in immunoglobulin binding and complex, humoral immune response, and immune response-activating signaling pathways. In combination with the PPI network and topological analysis, 4 hub genes (IGLL5, Jchain, POU2AF1, and Bach2) were identified. Pearson analysis showed that the expression changes of these hub genes were highly correlated with age. Among them, 3 hub genes (IGLL5, POU2AF1, and Bach2) were identified with good accuracy (AUC score > 0.7), indicating that these genes were the best indicators of age. Together, our results provided potential biomarkers IGLL5, POU2AF1, and Bach2 to identify individuals at high early risk of age-related disease to be targeted for early interventions and contribute to understanding the molecular mechanisms in the progression of aging.

Multi-omics analysis of multiple myeloma patients with differential response to first-line treatment

The genome backgrounds of multiple myeloma (MM) would affect the efficacy of specific treatment. However, the mutational and transcriptional landscapes in MM patients with differential response to first-line treatment remains unclear. We collected paired whole-exome sequencing (WES) and transcriptomic data of over 200 MM cases from MMRF-COMPASS project. R package, maftools was applied to analyze the somatic mutations and mutational signatures across MM samples. Differential expressed genes (DEG) was calculated using R package, DESeq2. The feature selection of the predictive model was determined by LASSO regression. In silico analysis revealed newly discovered recurrent mutated genes such as TTN, MUC16. TP53 mutation was observed more frequent in nonCR (complete remission) group with poor prognosis. DNA repair-associated mutational signatures were enriched in CR patients. Transcriptomic profiling showed that the activity of NF-kappa B and TGF-β pathways was suppressed in CR patients. A transcriptome-based response predictive model was constructed and showed promising predictive accuracy in MM patients receiving first-line treatment. Our study delineated distinctive mutational and transcriptional landscapes in MM patients with differential response to first-line treatment. Furthermore, we constructed a 20-gene predictive model which showed promising accuracy in predicting treatment response in newly diagnosed MM patients.

BRAFΔβ3-αC in-frame deletion mutants differ in their dimerization propensity, HSP90 dependence, and druggability

In-frame BRAF exon 12 deletions are increasingly identified in various tumor types. The resultant BRAFΔβ3-αC oncoproteins usually lack five amino acids in the β3-αC helix linker and sometimes contain de novo insertions. The dimerization status of BRAFΔβ3-αC oncoproteins, their precise pathomechanism, and their direct druggability by RAF inhibitors (RAFi) has been under debate. Here, we functionally characterize BRAFΔLNVTAP>F and two novel mutants, BRAFdelinsFS and BRAFΔLNVT>F, and compare them with other BRAFΔβ3-αC oncoproteins. We show that BRAFΔβ3-αC oncoproteins not only form stable homodimers and large multiprotein complexes but also require dimerization. Nevertheless, details matter as aromatic amino acids at the deletion junction of some BRAFΔβ3-αC oncoproteins, e.g., BRAFΔLNVTAP>F, increase their stability and dimerization propensity while conferring resistance to monomer-favoring RAFi such as dabrafenib or HSP 90/CDC37 inhibition. In contrast, dimer-favoring inhibitors such as naporafenib inhibit all BRAFΔβ3-αC mutants in cell lines and patient-derived organoids, suggesting that tumors driven by such oncoproteins are vulnerable to these compounds.

Characterization of clonal immunoglobulin heavy V-D-J gene rearrangements in Chinese patients with chronic lymphocytic leukemia: Clinical features and molecular profiles

Introduction

Several prognostic factors of chronic lymphocytic leukemia (CLL) have been identified, such as cytogenetic aberrations and recurrent gene mutations. B-cell receptor (BCR) signaling plays an important role in the tumorigenesis of CLL, and its clinical significance in predicting prognosis is also under study.

Methods

Therefore, we assessed the already-known prognostic markers, immunoglobulin heavy chain (IGH) gene usage and the associations among these factors in 71 patients diagnosed with CLL in our center from October 2017 to March 2022. Sequencing of IGH gene rearrangements was performed using Sanger sequencing or IGH-based next-generation sequencing, and the results were further analyzed for distinct IGH/IGHD/IGHJ genes and the mutational status of the clonotypic IGHV (IGH variable) gene.

Results

In summary, by analyzing the distribution of potential prognostic factors in CLL patients, we displayed a landscape of molecular profiles, confirmed the predictive value of recurrent genetic mutations and chromosome aberrations, and found that IGHJ3 was associated with favorable markers (mutated IGHV, trisomy 12), while IGHJ6 tended to correlate with unfavorable factors (unmutated IGHV, del17p).

Discussion

These results provided an indication for IGH gene sequencing in predicting the prognosis of CLL.

Identification of key genes in late-onset major depressive disorder through a co-expression network module

Late-onset major depressive disorder (LOD) increases the risk of disability and suicide in elderly patients. However, the complex pathological mechanism of LOD still remains unclear. We selected 10 LOD patients and 12 healthy control samples from the GSE76826 dataset for statistical analysis. Under the screening criteria, 811 differentially expressed genes (DEGs) were screened. We obtained a total of two most clinically significant modules through the weighted gene co-expression network analysis (WGCNA). Functional analysis of the genes in the most clinically significant modules was performed to explore the potential mechanism of LOD, followed by protein-protein interaction (PPI) analysis and hub gene identification in the core area of the PPI network. Furthermore, we identified immune infiltrating cells using the cell-type identification by estimating relative subsets of RNA transcripts (CIBERSORT) algorithm between healthy subjects and LOD patients with the GSE98793 dataset. Next, six hub genes (CD27, IL7R, CXCL1, CCR7, IGLL5, and CD79A) were obtained by intersecting hub genes with DEGs, followed by verifying the diagnostic accuracy with the receiver operating characteristic curve (ROC). In addition, we constructed the least absolute shrinkage and selection operator (LASSO) regression model for hub gene cross-validation. Finally, we found that CD27 and IGLL5 were good diagnostic indicators of LOD, and CD27 may be the key gene of immune function change in LOD. In conclusion, our research shows that the changes in the immune function may be an important mechanism in the development of LOD, which can provide some guidance for the related research of LOD in the future.

The potential link between Covid-19 and multiple myeloma: A new saga

BACKGROUND

Covid-19 is considered a primary respiratory disease-causing viral pneumonia and, in severe cases, leads to acute lung injury and acute respiratory distress syndrome (ARDS). In addition, though, extra-pulmonary manifestations of Covid-19 have been shown. Furthermore, severe acute respiratory distress syndrome coronavirus type 2 (SARS-CoV-2) infection may coexist with several malignancies, including multiple myeloma (MM).

METHODS

This critical literature review aimed to find the potential association between SARS-CoV-2 infection and MM in Covid-19 patients with underlying MM. Narrative literature and databases search revealed that ARDS is developed in both MM and Covid-19 due to hypercalcemia and proteasome dysfunction.

RESULTS

Notably, the expression of angiogenic factors and glutamine deficiency could link Covid-19 severity and MM in the pathogenesis of cardiovascular complications. MM and Covid-19 share thrombosis as a typical complication; unlike thrombosis in Covid-19, which reflects disease severity, thrombosis does not reflect disease severity in MM. In both conditions, thromboprophylaxis is essential to prevent pulmonary thrombosis and other thromboembolic disorders. Moreover, Covid-19 may exacerbate the development of acute kidney injury and neurological complications in MM patients.

CONCLUSION

These findings highlighted that MM patients might be a risk group for Covid-19 severity due to underlying immunosuppression and most of those patients need specific management in the Covid-19 era.

Myeloma Genome Project Panel is a Comprehensive Targeted Genomics Panel for Molecular Profiling of Patients with Multiple Myeloma

PURPOSE

We designed a comprehensive multiple myeloma targeted sequencing panel to identify common genomic abnormalities in a single assay and validated it against known standards.

EXPERIMENTAL DESIGN

The panel comprised 228 genes/exons for mutations, 6 regions for translocations, and 56 regions for copy number abnormalities (CNA). Toward panel validation, targeted sequencing was conducted on 233 patient samples and further validated using clinical FISH (translocations), multiplex ligation probe analysis (MLPA; CNAs), whole-genome sequencing (WGS; CNAs, mutations, translocations), or droplet digital PCR (ddPCR) of known standards (mutations).

RESULTS

Canonical immunoglobulin heavy chain translocations were detected in 43.2% of patients by sequencing, and aligned with FISH except for 1 patient. CNAs determined by sequencing and MLPA for 22 regions were comparable in 103 samples and concordance between platforms was R2 = 0.969. Variant allele frequency (VAF) for 74 mutations were compared between sequencing and ddPCR with concordance of R2 = 0.9849.

CONCLUSIONS

In summary, we have developed a targeted sequencing panel that is as robust or superior to FISH and WGS. This molecular panel is cost-effective, comprehensive, clinically actionable, and can be routinely deployed to assist risk stratification at diagnosis or posttreatment to guide sequencing of therapies.

Analysis of Genetic Alterations in Ocular Adnexal Mucosa-Associated Lymphoid Tissue Lymphoma With Whole-Exome Sequencing

Next-generation sequencing studies on ocular adnexal marginal zone lymphoma of mucosa-associated lymphoid tissue (OAML) have to date revealed several targets of genetic aberrations. However, most of our current understanding of the pathogenesis and prognosis of OAML is primarily based on studies conducted in populations from Europe and the US. Furthermore, the majority were based on formalin-fixed paraffin-embedded (FFPE) tissue, which generally has poor integrity and creates many sequencing artifacts. To better investigate the coding genome landscapes of OAML, especially in the Chinese population, we performed whole-exome sequencing of 21 OAML cases with fresh frozen tumor tissue and matched peripheral blood samples. IGLL5, as a novel recurrently mutated gene, was found in 24% (5/21) of patients, with a higher relapse rate (P=0.032). In addition, mutations of MSH6, DIS3, FAT1, and TMEM127 were found in 10% of cases. These novel somatic mutations indicate the existence of additional/alternative lymphomagenesis pathways in OAML. Moreover, the difference between our and previous studies suggests genetic heterogeneity of OAML between Asian and Western individuals.

The Dynamics of Nucleotide Variants in the Progression from Low-Intermediate Myeloma Precursor Conditions to Multiple Myeloma: Studying Serial Samples with a Targeted Sequencing Approach

Simple Summary

Multiple myeloma (MM), characterized by the expansion of plasma cells in the bone marrow, is the second most common hematological malignancy. This incurable cancer is consistently preceded by non-malignant asymptomatic precursor conditions known as monoclonal gammopathy of undetermined significance (MGUS) and/or smoldering multiple myeloma (SMM). These pre-stages are relatively frequent, but only a select percentage of them will progress to MM. However, it is still not possible to individually predict when and which patients will develop MM. Therefore, this study aimed to investigate the mutational profile in the progression in serial bone marrow samples with a custom targeted sequencing panel, designed to detect variants in myeloma-related genes. Remarkably, almost all variants identified in the MM samples were also already present in the pre-stages, sometimes even many years before the progression. These results provide new important insights into the molecular mechanisms of the precursor conditions and progression to MM.

Abstract

Multiple myeloma (MM), or Kahler’s disease, is an incurable plasma cell (PC) cancer in the bone marrow (BM). This malignancy is preceded by one or more asymptomatic precursor conditions, monoclonal gammopathy of undetermined significance (MGUS) and/or smoldering multiple myeloma (SMM). The molecular mechanisms and exact cause of this progression are still not completely understood. In this study, the mutational profile underlying the progression from low–intermediate risk myeloma precursor conditions to MM was studied in serial BM smears. A custom capture-based sequencing platform was developed, including 81 myeloma-related genes. The clonal evolution of single nucleotide variants and short insertions and deletions was studied in serial BM smears from 21 progressed precursor patients with a median time of progression of six years. From the 21 patients, four patients had no variation in one of the 81 studied genes. Interestingly, in 16 of the 17 other patients, at least one variant present in MM was also detected in its precursor BM, even years before progression. Here, the variants were present in the pre-stage at a median of 62 months before progression to MM. Studying these paired BM samples contributes to the knowledge of the evolutionary genetic landscape and provides additional insight into the mutational behavior of mutant clones over time throughout progression.

Integrative Analysis of Immune-Related Genes in the Tumor Microenvironment of Renal Clear Cell Carcinoma and Renal Papillary Cell Carcinoma

Kidney cancer encompasses a range of primary cancers, such as clear cell renal cell carcinoma (ccRCC) and papillary renal cell carcinoma (pRCC). Our knowledge about the tumor microenvironment (TME) of kidney cancer is still limited. Therefore, we comprehensively assessed the TME of kidney cancers (including ccRCC and pRCC) using the ESTIAMTE, and CIBERSORT algorithms, and conducted distinct functional and correlation analyses with data from The Cancer Genome Atlas (TCGA), International Cancer Genome Consortium (ICGC), Gene Expression Omnibus (GEO), Connectivity map and CellMiner database. Next, we identified two immune-related hub genes, IGLL5 and IL2RA, which play essential roles in the TME as well as on survival in ccRCC and pRCC. Furthermore, ccRCC and pRCC samples from our medical center were collected to verify the clinical application value of these two immune-related genes. A specific enrichment analysis of immune cells related to IGLL5 and IL2RA was also conducted in two types of renal cell cancer. Based on selected genes, we predicted the drug response and uncovered novel drug candidate for RCC treatment. Considering the unfavorable outcomes of kidney cancer and emerging interest in TME-targeted treatments, our results may offer insights into immune-related molecular mechanisms and possible targets to control the kidney cancer.

Genome Instability in Multiple Myeloma: Facts and Factors

Multiple myeloma (MM) is a malignant neoplasm of terminally differentiated immunoglobulin-producing B lymphocytes called plasma cells. MM is the second most common hematologic malignancy, and it poses a heavy economic and social burden because it remains incurable and confers a profound disability to patients. Despite current progress in MM treatment, the disease invariably recurs, even after the transplantation of autologous hematopoietic stem cells (ASCT). Biological processes leading to a pathological myeloma clone and the mechanisms of further evolution of the disease are far from complete understanding. Genetically, MM is a complex disease that demonstrates a high level of heterogeneity. Myeloma genomes carry numerous genetic changes, including structural genome variations and chromosomal gains and losses, and these changes occur in combinations with point mutations affecting various cellular pathways, including genome maintenance. MM genome instability in its extreme is manifested in mutation kataegis and complex genomic rearrangements: chromothripsis, templated insertions, and chromoplexy. Chemotherapeutic agents used to treat MM add another level of complexity because many of them exacerbate genome instability. Genome abnormalities are driver events and deciphering their mechanisms will help understand the causes of MM and play a pivotal role in developing new therapies.

Ultra-deep sequencing mutation analysis of the BCR/ABL1 kinase domain in newly diagnosed chronic myeloid leukemia patients

Ultra-deep sequencing detects low-frequency genetic mutations with high sensitivity. We used this approach to prospectively examine mutations in the BCR/ABL1 tyrosine kinase from patients with newly diagnosed, chronic-phase chronic myeloid leukemia (CML) treated with the tyrosine kinase inhibitor nilotinib. Between May 2013 and November 2014, 50 patients from 18 institutions were enrolled in the study. We screened 103 somatic mutations and found that mutations in the P-loop domain were the most frequent (173/454 mutations in the P-loop) and noted the presence of the V299 L mutation (dasatinib-resistant/nilotinib-sensitive) in 98 % of patients (49/50). No patients had Y253H, E255 V, or F359 V/C/I mutations, which would recommend dasatinib rather than nilotinib treatment. The S417Y mutation was associated with lower achievement of a major molecular response (MMR) at 6 months, and the V371A mutation was associated with reduced MMR and MR^4.5 durations (MMR for 2 years: 100 % for no mutation vs. 75 % for mutation, P=0.039; MR^4.5 for 15 months: 94.1 % vs. 25 %, P=0.002). Patients with known nilotinib-resistant mutations had lower rates of MR^4.5 achievement. In conclusion, ultra-deep sequencing is a sensitive method for genetic-based treatment decisions. Based on the results of these mutational analyses, nilotinib treatment is a promising option for Korean patients with CML.

Investigating single amino acid substitutions in PIM1 kinase: A structural genomics approach

PIM1, is a serine/threonine proto-oncogene kinase, involved in many biological functions, including cell survival, proliferation, and differentiation, thus play a key role in oncogenesis. It plays a crucial role in the onset and progression of various hematopoietic and non-hematopoietic malignancies, including acute myeloid leukemia and prostate cancer. Mutations in PIM1, especially in its kinase domain, can induce abnormal structural changes and thus alter functionalities that can lead to disease progression and other complexities. Herein, we have performed an extensive analysis of the PIM1 mutations at sequence and structure level while utilizing state-of-the-art computational approaches. Based on the impact on PIM1, numerous pathogenic and destabilizing mutations were identified and subsequently analyzed in detail. Finally, two amino acid substitutions (W109C and F147C) in the kinase domain of PIM1 were selected to explore their impact on the PIM1 structure in a time evolution manner using all-atom molecular dynamics (MD) simulations for 200 ns. MD results indicate significant conformational altercations in the structure of PIM1, especially upon F147C mutation. This study provides a significant insight into the PIM1 dysfunction upon single amino acid substitutions, which can be utilized to get insights into the molecular basis of PIM1-associated disease progression.

Validation of the EuroClonality-NGS DNA capture panel as an integrated genomic tool for lymphoproliferative disorders

Current diagnostic standards for lymphoproliferative disorders include multiple tests for detection of clonal immunoglobulin (IG) and/or T-cell receptor (TCR) rearrangements, translocations, copy-number alterations (CNAs), and somatic mutations. The EuroClonality-NGS DNA Capture (EuroClonality-NDC) assay was designed as an integrated tool to characterize these alterations by capturing IGH switch regions along with variable, diversity, and joining genes of all IG and TCR loci in addition to clinically relevant genes for CNA and mutation analysis. Diagnostic performance against standard-of-care clinical testing was assessed in a cohort of 280 B- and T-cell malignancies from 10 European laboratories, including 88 formalin-fixed paraffin-embedded samples and 21 reactive lesions. DNA samples were subjected to the EuroClonality-NDC protocol in 7 EuroClonality-NGS laboratories and analyzed using a bespoke bioinformatic pipeline. The EuroClonality-NDC assay detected B-cell clonality in 191 (97%) of 197 B-cell malignancies and T-cell clonality in 71 (97%) of 73 T-cell malignancies. Limit of detection (LOD) for IG/TCR rearrangements was established at 5% using cell line blends. Chromosomal translocations were detected in 145 (95%) of 152 cases known to be positive. CNAs were validated for immunogenetic and oncogenetic regions, highlighting their novel role in confirming clonality in somatically hypermutated cases. Single-nucleotide variant LOD was determined as 4% allele frequency, and an orthogonal validation using 32 samples resulted in 98% concordance. The EuroClonality-NDC assay is a robust tool providing a single end-to-end workflow for simultaneous detection of B- and T-cell clonality, translocations, CNAs, and sequence variants.

Structural and functional characterization of multiple myeloma associated cytoplasmic poly(A) polymerase FAM46C

Background

Multiple myeloma (MM) is a hematologic malignancy characterized by the accumulation of aberrant plasma cells within the bone marrow. The high frequent mutation of family with sequence similarity 46, member C (FAM46C) is closely related with the occurrence and progression of MM. Recently, FAM46C has been identified as a non‐canonical poly(A) polymerase (PAP) that functions as a tumor suppressor in MM. This study aimed to elucidate the structural features of this novel non‐canonical PAP and how MM‐related mutations affect the structural and biochemical properties of FAM46C, eventually advancing our understandings towards FAM46C mutation‐related MM occurrence.

Methods

We purified and crystallized a mammalian FAM46C construct, and solved its structure. Next, we characterized the property of FAM46C as a PAP through a combination of structural analysis, site‐directed mutagenesis and biochemical assays, and by comparison with its homolog FAM46B. Finally, we structurally analyzed MM‐related FAM46C mutations and tested the enzymatic activity of corresponding mutants.

Results

We determined the crystal structure of a mammalian FAM46C protein at 2.35 Å, and confirmed that FAM46C preferentially consumed adenosine triphosphate (ATP) and extended A‐rich RNA substrates. FAM46C showed a weaker PAP activity than its homolog FAM46B, and this difference was largely dependent on the residue variance at particular sites. Of them, residues at positions 77, 290, and 298 of mouse FAM46C were most important for the divergence in enzymatic activity. Among the MM‐associated FAM46C mutants, those residing at the catalytic site (D90G and D90H) or putative RNA‐binding site (I155L, S156F, D182Y, F184L, Y247V, and M270V) showed abolished or compromised PAP activity of FAM46C, while N72A and S248A did not severely affect the PAP activity. FAM46C mutants D90G, D90H, I155L, S156F, F184L, Y247V, and M270V had significantly lower inhibitory effect on apoptosis of RPMI‐8226 cells as compared to wild‐type FAM46C.

Conclusions

FAM46C is a prokaryotic‐like PAP with preference for A‐rich RNA substrates, and showed distinct enzymatic efficiency with its homolog FAM46B. The MM‐related missense mutations of FAM46C lead to various structural and biochemical outcomes to the protein.

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

IGLL5 is correlated with tumor-infiltrating immune cells in clear cell renal cell carcinoma

Renal cell carcinomas (RCCs) account for about 90% of renal tumors, and their major histological subtype is ccRCC (clear cell RCC). Increasing evidence has indicated that the tumor microenvironment plays a significant role in the occurrence and development of ccRCC. In this study, we used ESTIMATE and CIBERSORT computational methods to calculate the proportion of immune and stromal components and the rate of TICs (tumor‐infiltrating immune cells) in 539 ccRCC samples from The Cancer Genome Atlas database. By examining the intersection of the differentially expressed genes obtained by the protein–protein interaction network and Cox regression analysis, we identified only one overlapping gene: IGLL5 (immunoglobulin lambda‐like polypeptide 5). We report that IGLL5 expression is correlated with TICs. Furthermore, our immunoinfiltration analyses revealed that three types of TIC are positively correlated with IGLL5 expression. IGLL5 may have potential as a prognostic biomarker of ccRCC.

Clinical utility of target capture-based panel sequencing in hematological malignancies: A multicenter feasibility study

Although next‐generation sequencing‐based panel testing is well practiced in the field of cancer medicine for the identification of target molecules in solid tumors, the clinical utility and clinical issues surrounding panel testing in hematological malignancies have yet to be fully evaluated. We conducted a multicenter prospective clinical sequencing study to verify the feasibility of a panel test for hematological tumors, including acute myeloid leukemia, acute lymphoblastic leukemia, multiple myeloma, and diffuse large B‐cell lymphoma. Out of 96 eligible patients, 79 patients (82%) showed potentially actionable findings, based on the clinical sequencing assays. We identified that genetic alterations with a strong clinical significance were found at a higher frequency in terms of diagnosis (n = 60; 63%) and prognosis (n = 61; 64%) than in terms of therapy (n = 8; 8%). Three patients who harbored a germline mutation in either DDX41 (n = 2) or BRCA2 (n = 1) were provided with genetic counseling. At 6 mo after sequencing, clinical actions based on the diagnostic (n = 5) or prognostic (n = 3) findings were reported, but no patients were enrolled in a clinical trial or received targeted therapies based on the sequencing results. These results suggest that panel testing for hematological malignancies would be feasible given the availability of useful diagnostic and prognostic information. This study is registered with the UMIN Clinical Trial Registry (UMIN000029879, multiple myeloma; UMIN000031343, adult acute myeloid leukemia; UMIN000033144, diffuse large B‐cell lymphoma; and UMIN000034243, childhood leukemia).

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.

Application of Next-Generation Sequencing for the Genomic Characterization of Patients with Smoldering Myeloma

Genomic analysis could contribute to a better understanding of the biological determinants of the evolution of multiple myeloma (MM) precursor disease and an improved definition of high-risk patients. To assess the feasibility and value of next-generation sequencing approaches in an asymptomatic setting, we performed a targeted gene mutation analysis and a genome-wide assessment of copy number alterations (CNAs) by ultra-low-pass whole genome sequencing (ULP-WGS) in six patients with monoclonal gammopathy of undetermined significance and 25 patients with smoldering MM (SMM). Our comprehensive genomic characterization highlighted heterogeneous but substantial values of the tumor fraction, especially in SMM; a rather high degree of genomic complexity, in terms of both mutations and CNAs, and inter-patient variability; a higher incidence of gene mutations and CNAs in SMM, confirming ongoing evolution; intraclonal heterogeneity; and instances of convergent evolution. ULP-WGS of these patients proved effective in revealing the marked genome-wide level of their CNAs, most of which are not routinely investigated. Finally, the analysis of our small SMM cohort suggested that chr(8p) deletions, the DNA tumor fraction, and the number of alterations may have clinical relevance in the progression to overt MM. Although validation in larger series is mandatory, these findings highlight the promising impact of genomic approaches in the clinical management of SMM.

Plasma proteomic profiles differ between European and North American myotid bats colonized by Pseudogymnoascus destructans

Emerging fungal diseases have become challenges for wildlife health and conservation. North American hibernating bat species are threatened by the psychrophilic fungus Pseudogymnoascus destructans (Pd) causing the disease called white-nose syndrome (WNS) with unprecedented mortality rates. The fungus is widespread in North America and Europe, however, disease is not manifested in European bats. Differences in epidemiology and pathology indicate an evolution of resistance or tolerance mechanisms towards Pd in European bats. We compared the proteomic profile of blood plasma in healthy and Pd-colonized European Myotis myotis and North American Myotis lucifugus in order to identify pathophysiological changes associated with Pd colonization, which might also explain the differences in bat survival. Expression analyses of plasma proteins revealed differences in healthy and Pd-colonized M. lucifugus, but not in M. myotis. We identified differentially expressed proteins for acute phase response, constitutive and adaptive immunity, oxidative stress defence, metabolism and structural proteins of exosomes and desmosomes, suggesting a systemic response against Pd in North American M. lucifugus but not European M. myotis. The differences in plasma proteomic profiles between European and North American bat species colonized by Pd suggest European bats have evolved tolerance mechanisms towards Pd infection.

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.

Ultra-low depth sequencing of plasma cell DNA for the detection of copy number aberrations in multiple myeloma

Cytogenetic abnormalities are powerful prognostic factors in multiple myeloma (MM) and are routinely analyzed by FISH on bone marrow (BM) plasma cells (PC). Although considered the gold standard, FISH experiments can be laborious and expensive. Therefore, array-CGH (aCGH) has been introduced as an alternative approach for detecting copy number aberrations (CNA), reducing the number of FISH experiments per case and yielding genome-wide information. Currently, next generation sequencing (NGS) technologies offer new perspectives for the diagnostic workup of malignant disorders. In this study, we examined ultra-low depth whole genome sequencing (LDS) as a valid alternative for aCGH for the detection of CNA in BM PC in MM. To this end, BM aspirates obtained in a diagnostic setting from 20 MM cases were analyzed. CD138+ cell-sorted samples were subjected to FISH analysis. DNA was extracted for subsequent aCGH and LDS analysis. CNA were detected by aCGH and LDS in all but one case. Importantly, all CNA identified by parallel first generation aCGH analysis were also detected by LDS, along with six additional CNA in five cases. One of these additional aberrations was in a region of prognostic importance in MM and was confirmed using FISH. However, risk stratification in these particular cases was unaffected. Thus, a perfectly concordant prognostication between array-CGH and LDS was observed. This validates LDS as a novel and cost-efficient tool for the detection of CNA in MM.

Identification of genes of prognostic value in the ccRCC microenvironment from TCGA database

Background

Clear cell renal cell carcinoma (ccRCC) is the most common pathological subtype of renal cell carcinoma. Bioinformatics analyses were used to screen candidate genes associated with the prognosis and microenvironment of ccRCC and elucidate the underlying molecular mechanisms of action.

Methods

The gene expression profiles and clinical data of ccRCC patients were downloaded from The Cancer Genome Atlas database. The ESTIMATE algorithm was used to compute the immune and stromal scores of patients. Based on the median immune/stromal scores, all patients were sorted into low‐ and high‐immune/stromal score groups. Differentially expressed genes (DEGs) were extracted from high‐ versus low‐immune/stromal score groups and were described using functional annotations and protein‒protein interaction (PPI) network.

Results

Patients in the high‐immune/stromal score group had poorer survival outcome. In total, 95 DEGs (48 upregulated and 47 downregulated genes) were screened from the gene expression profiles of patients with high immune and stromal scores. The genes were primarily involved in six signaling pathways. Among the 95 DEGs, 43 were markedly related to overall survival of patients. The PPI network identified the top 10 hub genes—CD19, CD79A, IL10, IGLL5, POU2AF1, CCL19, AMBP, CCL18, CCL21, and IGJ—and four modules. Enrichment analyses revealed that the genes in the most important module were involved in the B‐cell receptor signaling pathway.

Conclusion

This study mainly revealed the relationship between the ccRCC microenvironment and prognosis of patients. These results also increase the understanding of how gene expression patterns can impact the prognosis and development of ccRCC by modulating the tumor microenvironment. The results could contribute to the search for ccRCC biomarkers and therapeutic targets.

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.

Applications and analysis of targeted genomic sequencing in cancer studies

Next Generation Sequencing (NGS) has dramatically improved the flexibility and outcomes of cancer research and clinical trials, providing highly sensitive and accurate high-throughput platforms for large-scale genomic testing. In contrast to whole-genome (WGS) or whole-exome sequencing (WES), targeted genomic sequencing (TS) focuses on a panel of genes or targets known to have strong associations with pathogenesis of disease and/or clinical relevance, offering greater sequencing depth with reduced costs and data burden. This allows targeted sequencing to identify low frequency variants in targeted regions with high confidence, thus suitable for profiling low-quality and fragmented clinical DNA samples. As a result, TS has been widely used in clinical research and trials for patient stratification and the development of targeted therapeutics. However, its transition to routine clinical use has been slow. Many technical and analytical obstacles still remain and need to be discussed and addressed before large-scale and cross-centre implementation. Gold-standard and state-of-the-art procedures and pipelines are urgently needed to accelerate this transition. In this review we first present how TS is conducted in cancer research, including various target enrichment platforms, the construction of target panels, and selected research and clinical studies utilising TS to profile clinical samples. We then present a generalised analytical workflow for TS data discussing important parameters and filters in detail, aiming to provide the best practices of TS usage and analyses.

Lineage-negative lymphoma with a helper innate lymphoid cell phenotype

Helper innate lymphoid cells (ILCs) were recently recognized as lineage-negative lymphoid cells that do not express rearranged receptors and have important effector and regulatory functions in innate immunity. However, to our knowledge, no cases of hematological malignancies arising from helper ILCs have ever been reported in the literature. Here, we report a case of a 17-year-old man with multiple lymphadenopathy who was diagnosed with lineage-negative lymphoma that displayed a helper ILC phenotype. Histological examination showed large monomorphic atypical lymphoid cells with prominent nucleoli and abundant eosinophilic cytoplasms with scattered and patchy distributions. Large amounts of histiocytes and infiltrating lymphocytes were observed in the background. Immunostaining revealed positive LCA and CD79a expression but negative expression of all lineage markers. IG and TCR rearrangement analysis showed no clonal rearrangements. Tumor cells strongly expressed helper ILC phenotypic markers, such as CD127, IL-1R, GATA3, ST2, IL-17Rβ, and RANKL, and helper ILC-produced cytokines, such as IL-4 and GM-CSF. PD-L1/PD-L2-positive histiocytes and FOXP3-positive Tregs were observed in the tumor microenvironment. Flow cytometry of bone marrow at recurrence was positive for IL-1R and negative for T, B, NK, and myelogenous lineage markers. TP53 sequencing showed that exon 5 was replaced with an intergenic sequence of chromosome 21. Next-generation sequencing demonstrated a novel IGLV2-14/IGLL5 fusion and mutations or deletions of tumor suppressor genes, such as PTPRB, PPP2CB, and UPK1A. This tumor was very aggressive, resistant to chemotherapy, recurred with bone marrow involvement, and caused the death of the patient within 6 months. To our knowledge, this is the first report of a hematological malignancy potentially arising from helper ILCs. We propose negativity for lineage markers and positivity for CD127/IL-1R in combination with specific transcription factor expression as markers of this tumor. This finding represents a novel addition to the growing spectrum of hematological malignancies.

Minimal Residual Disease Assessment Within the Bone Marrow of Multiple Myeloma: A Review of Caveats, Clinical Significance and Future Perspectives

There is an increasing clinical interest in the measure and achievement of minimal residual disease (MRD) negativity in the bone marrow of Multiple Myeloma (MM) patients, as defined equally either by Multicolor Flow Cytometry (MFC) or by Next Generation Sequencing (NGS) technologies. At present, modern technologies allow to detect up to one on 104 or on 105 or even on 106 cells, depending on their throughput. MFC approaches, which have been progressively improved up to the so-called Next Generation Flow (NGF), and NGS, which proved clear advantages over ASO-PCR, can detect very low levels of residual disease in the BM. These methods are actually almost superimposable, in terms of MRD detection power, supporting the lack of unanimous preference for either technique on basis of local availability. However, some technical issues are still open: the optimal assay to use to detect either phenotype (e.g., next generation multidimensional flow cytometry, imaging) or genotype aberrations (e.g., ASO-RQ PCR, digital droplet PCR, NGS) and their standardization, the sample source (BM or peripheral blood, PB) and its pre-processing (red-cell lysis vs. Ficoll, fresh vs. frozen samples, requirement of CD138+ cells enrichment). Overall, MRD negativity is considered as the most powerful predictor of favorable long-term outcomes in MM and is likely to represent the major driver of treatment strategies in the near future. In this manuscript, we reviewed the main pitfalls and caveats of MRD detection within bone marrow in MM patients after front-line therapy, highlighting the improving of the currently employed technology and describing alternative methods for MRD testing in MM, such as liquid biopsy.

Next Generation Sequencing-based Validation of the Revised International Staging System for Multiple Myeloma: An Analysis of the MMRF CoMMpass Study

INTRODUCTION

The clinical application of the Revised International Staging System (R-ISS) for multiple myeloma may be limited by heterogeneity in clinical interphase fluorescent in situ hybridization (FISH) practices for detecting chromosomal abnormalities (CAs). Next generation sequencing (NGS)-based FISH (Seq-FISH) has demonstrated improved sensitivity and similar specificity relative to clinical FISH, and provides a standardized, single-pass method for identifying high-risk CAs. To date, calculating R-ISS stage using Seq-FISH (R-ISS-NGS) has not been validated.

PATIENTS AND METHODS

We identified 672 patients with sufficient data to calculate R-ISS-NGS from the Multiple Myeloma Research Foundation (MMRF) CoMMpass Study. R-ISS-NGS was calculated from original ISS stage, lactate dehydrogenase, and CAs detected by Seq-FISH. Endpoints included overall survival and progression-free survival. We conducted multivariate analyses controlling for age and gender in order to compare outcomes across stages I to III of both the original ISS and R-ISS-NGS.

RESULTS

The median follow-up was 24 months. The R-ISS-NGS resulted in significant redistribution of patients into stage II, relative to the original ISS. With respect to stage I, R-ISS-NGS stages II and III of were associated with worse progression-free survival or overall survival, more so than the staging schema of the ISS, thus validating the use of Seq-FISH in staging.

CONCLUSION

Using CAs detected by Seq-FISH and data from the CoMMpass study, we validated the R-ISS with a large, generalizable cohort. This study validates the substitution of Seq-FISH for clinical FISH, especially in large registry studies. Additionally, use of the validated R-ISS-NGS will strengthen outcomes research generated from the CoMMpass study.