Despite distinct clinical presentation and outcome, systemic, primary cutaneous, and breast implant-associated anaplastic large cell lymphomas (S-, PC-, BI-ALCL) ALK-negative (ALK-) show similar histopathological features including the presence of the "hallmark" cells with horseshoe-shaped nuclei and CD30 protein expression. The purpose was to better characterize these three entities using immunohistochemistry and FISH (Fluorescent in situ hybridization) to identify biomarkers differently expressed and that might be involved in their pathogenesis. Twenty-two S-ALCL ALK-, 13 PC-ALCL, and 2 BI-ALCL were included. Cases were tested for P53, P63, MUM1, MYC, GATA3, p-STAT3, PD1, and PDL1 protein expression and DUP22, TP53, TP63, MYC, and PDL1 chromosomal aberrations. As expected, S-ALCL ALK- patients had adverse outcome compare to PC and BI-ALCL. No difference was observed between the three groups concerning protein expression except for MUM1 that was significantly more frequently expressed in S-ALCL ALK- compared to PC-ALCL. In particular, constitutive activation of the STAT3 pathway and PDL1/PD1 immune-checkpoint expression was present in the three entities. TP53 deletion and PDL1 gene amplification were the commonest cytogenetic alterations and were present in the three entities. None of the studied biological parameters was associated with prognosis. Despite distinct clinical behavior, S-ALCL ALK-, PC-ALCL, and BI-ALCL share similar biological features. Larger series should be investigated with the current approach to determine more precisely the activity and the prognostic value of these biomarkers and pathways in each group.

BACKGROUND: Programmed cell death receptor 1 ligand 1 (PD-L1) expression in various tumors, including hematologic malignancies, has recently become a research topic of great interest. We performed a meta-analysis to evaluate the prognostic and clinicopathological value of PD-L1 expressed in tumor cells of patients with diffuse large B-cell lymphoma (DLBCL).
METHODS: Relevant studies were identified from PubMed, EMBASE, Web of Science and the Cochrane Library. The hazard ratio (HR) and 95% confidence interval (95% CI) were used for analyzing survival outcomes, and the odds ratio (OR) was used for analyzing clinicopathological parameters.
RESULTS: Pooled results showed that tumor cell PD-L1 expression is associated with poor overall survival (OS) (HR = 2.128, 95% CI: 1.341-3.378, P = 0.001), the non-germinal center B-cell-like subtype (OR = 2.891, 95% CI: 2.087-4.003, P < 0.000), high international prognostic index score (3-5) (OR = 1.552, 95% CI: 1.111-2.169, P = 0.010), B symptoms (OR = 1.495, 95% Cl: 1.109-2.015, P = 0.008), positive MUM1 expression (OR = 3.365, 95% Cl: 1.578-7.175, P = 0.002) and negative BCL6 expression (OR = 0.414, 95% Cl: 0.217-0.792, P = 0.008). Sensitivity analysis showed that there was no publication bias among these studies.
CONCLUSIONS: Our meta-analysis supported the idea that tumor cell PD-L1 expression may represent a promising biomarker for predicting poor prognosis and is associated with adverse clinicopathologic features in DLBCL patients.

Diffuse large B-cell lymphoma is categorized by gene expression profiling into germinal center (GCB) and activated B-cell (ABC) subtype, also referred to as non-germinal center B-cell (non-GCB) by immunohistochemistry. ABC DLBCL is characterized by NF-κB pathway activation and high expression of IRF4/MUM1, a key transcription factor in B cell differentiation. Patients with ABC DLBCL have a significantly worse outcome when treated with standard chemotherapy (R-CHOP). Lenalidomide have shown activity in the ABC-DLBCL in combination with R-CHOP. But about 40% of patients remain resistant. We present the experience of treatment of a patient with generalized non-GCB-DLBCL using the intensive protocol R-mNHL-BFM-90 with lenalidomide.

The total number of acquired melanocytic nevi on the skin is strongly correlated with melanoma risk. Here we report a meta-analysis of 11 nevus GWAS from Australia, Netherlands, UK, and USA comprising 52,506 individuals. We confirm known loci including MTAP, PLA2G6, and IRF4, and detect novel SNPs in KITLG and a region of 9q32. In a bivariate analysis combining the nevus results with a recent melanoma GWAS meta-analysis (12,874 cases, 23,203 controls), SNPs near GPRC5A, CYP1B1, PPARGC1B, HDAC4, FAM208B, DOCK8, and SYNE2 reached global significance, and other loci, including MIR146A and OBFC1, reached a suggestive level. Overall, we conclude that most nevus genes affect melanoma risk (KITLG an exception), while many melanoma risk loci do not alter nevus count. For example, variants in TERC and OBFC1 affect both traits, but other telomere length maintenance genes seem to affect melanoma risk only. Our findings implicate multiple pathways in nevogenesis.

Mycosis fungoides (MF) is an indolent cutaneous T-cell lymphoma and may transform into large cell lymphoma in the disease course. The incidence of MF in Taiwan is lower as compared to that in the West. In this study we aimed to characterise the clinicopathological, immunohistochemical, and genetic features of transformed MF (t-MF) in Taiwan. We retrospectively collected MF cases from April 2004 to April 2015 from four medical centres in Taiwan, reviewed the clinical history and histopathology, and performed immunohistochemistry, in situ hybridisation for EBV (EBER), and fluorescence in situ hybridisation (FISH) for DUSP22/MUM1 gene translocation. Fifty-one specimens from 32 patients with MF were identified with a male to female ratio of 1.5:1 and a median age of 50.5 (range 16-82). Tumours from 11 patients (34%) underwent large cell transformation, with the median age at 61 (range 26-82). The tumour cells of t-MF expressed CD30 and MUM1 in 82% and 100% cases, respectively. CD56 was expressed in two (10%) of 21 MF cases and two (18%) of 11 t-MF cases, respectively; and all four CD56-positive cases were of a helper T-cell phenotype. All CD56 expressing MF and t-MF tumours tested for EBER were negative. FISH study showed rearranged DUSP22/IRF4 in one (9%) of 11 t-MF cases, but not in any of the 19 non-transformed MF specimens. Four patients with t-MF died of disease and six were alive with disease in a median follow-up time of 25 months (mean 44.7 months). Large cell transformation and aberrant CD56 expression were more frequent in patients with MF in Taiwan compared to those in the West. Larger case series and/or national studies are needed to clarify the significance and impact of large cell transformation on the prognosis of patients with MF.

Most expression quantitative trait locus (eQTL) studies to date have been performed in heterogeneous tissues as opposed to specific cell types. To better understand the cell-type-specific regulatory landscape of human melanocytes, which give rise to melanoma but account for <5% of typical human skin biopsies, we performed an eQTL analysis in primary melanocyte cultures from 106 newborn males. We identified 597,335

Waldenström macroglobulinemia (WM)/lymphoplasmacytic lymphoma (LPL) is a rare, chronic B-cell lymphoma with high heritability. We conduct a two-stage genome-wide association study of WM/LPL in 530 unrelated cases and 4362 controls of European ancestry and identify two high-risk loci associated with WM/LPL at 6p25.3 (rs116446171, near EXOC2 and IRF4; OR = 21.14, 95% CI: 14.40-31.03, P = 1.36 × 10

Recent studies have demonstrated that the immunomodulatory drugs (IMiDs) lead to the degradation of the transcription factors Ikaros and Aiolos. However, why their loss subsequently leads to multiple myeloma (MM) cell death remains unclear. Using CRISPR-Cas9 genome editing, we have deleted

Alterations of epigenetic proteins that modulate the gene repressive lysine 27 on histone H3 (H3K27me) are recurrent features in cancers, including multiple myeloma (MM). The histone demethylase UTX/KDM6A, mutated in up to 10% of cases of MM activates genes by removing the H3K27me3 repressive histone mark, counteracting EZH2. RNA-sequencing studies showed that UTX upregulated genes in association with loss of H3K27me. Treatment of MM cell lines with an EZH2 inhibitor preferentially slowed growth of

EBV causes human B-cell lymphomas and transforms B cells in vitro. EBNA3C, an EBV protein expressed in latently-infected cells, is required for EBV transformation of B cells in vitro. While EBNA3C undoubtedly plays a key role in allowing EBV to successfully infect B cells, many EBV+ lymphomas do not express this protein, suggesting that cellular mutations and/or signaling pathways may obviate the need for EBNA3C in vivo under certain conditions. EBNA3C collaborates with EBNA3A to repress expression of the CDKN2A-encoded tumor suppressors, p16 and p14, and EBNA3C-deleted EBV transforms B cells containing a p16 germline mutation in vitro. Here we have examined the phenotype of an EBNAC-deleted virus (Δ3C EBV) in a cord blood-humanized mouse model (CBH). We found that the Δ3C virus induced fewer lymphomas (occurring with a delayed onset) in comparison to the wild-type (WT) control virus, although a subset (10/26) of Δ3C-infected CBH mice eventually developed invasive diffuse large B cell lymphomas with type III latency. Both WT and Δ3C viruses induced B-cell lymphomas with restricted B-cell populations and heterogeneous T-cell infiltration. In comparison to WT-infected tumors, Δ3C-infected tumors had greatly increased p16 levels, and RNA-seq analysis revealed a decrease in E2F target gene expression. However, we found that Δ3C-infected tumors expressed c-Myc and cyclin E at similar levels compared to WT-infected tumors, allowing cells to at least partially bypass p16-mediated cell cycle inhibition. The anti-apoptotic proteins, BCL2 and IRF4, were expressed in Δ3C-infected tumors, likely helping cells avoid c-Myc-induced apoptosis. Unexpectedly, Δ3C-infected tumors had increased T-cell infiltration, increased expression of T-cell chemokines (CCL5, CCL20 and CCL22) and enhanced type I interferon response in comparison to WT tumors. Together, these results reveal that EBNA3C contributes to, but is not essential for, EBV-induced lymphomagenesis in CBH mice, and suggest potentially important immunologic roles of EBNA3C in vivo.

Primary effusion lymphoma (PEL) is caused by Kaposi's sarcoma-associated herpesvirus. Our understanding of PEL is poor and therefore treatment strategies are lacking. To address this need, we conducted genome-wide CRISPR/Cas9 knockout screens in eight PEL cell lines. Integration with data from unrelated cancers identifies 210 genes as PEL-specific oncogenic dependencies. Genetic requirements of PEL cell lines are largely independent of Epstein-Barr virus co-infection. Genes of the NF-κB pathway are individually non-essential. Instead, we demonstrate requirements for IRF4 and MDM2. PEL cell lines depend on cellular cyclin D2 and c-FLIP despite expression of viral homologs. Moreover, PEL cell lines are addicted to high levels of MCL1 expression, which are also evident in PEL tumors. Strong dependencies on cyclin D2 and MCL1 render PEL cell lines highly sensitive to palbociclib and S63845. In summary, this work comprehensively identifies genetic dependencies in PEL cell lines and identifies novel strategies for therapeutic intervention.

PURPOSE: Advanced pancreatic cancer is a highly refractory disease almost always associated with survival of little more than a year. New interventions based on novel targets are needed. We aim to identify new genetic determinants of overall survival (OS) in patients after treatment with gemcitabine using genome-wide screens of germline DNA. We aim also to support these findings with in vitro functional analysis.
PATIENTS AND METHODS: Genome-wide screens of germline DNA in two independent cohorts of pancreatic cancer patients (from the Cancer and Leukemia Group B (CALGB) 80303 and the Mayo Clinic) were used to select new genes associated with OS. The vitamin D receptor gene (VDR) was selected, and the interactions of genetic variation in VDR with circulating vitamin D levels and gemcitabine treatment were evaluated. Functional effects of common VDR variants were also evaluated in experimental assays in human cell lines.
RESULTS: The rs2853564 variant in VDR was associated with OS in patients from both the Mayo Clinic (HR 0.81, 95% CI 0.70-0.94, p = 0.0059) and CALGB 80303 (HR 0.74, 0.63-0.87, p = 0.0002). rs2853564 interacted with high pre-treatment levels of 25-hydroxyvitamin D (25(OH)D, a measure of endogenous vitamin D) (p = 0.0079 for interaction) and with gemcitabine treatment (p = 0.024 for interaction) to confer increased OS. rs2853564 increased transcriptional activity in luciferase assays and reduced the binding of the IRF4 transcription factor.
CONCLUSION: Our findings propose VDR as a novel determinant of survival in advanced pancreatic cancer patients. Common functional variation in this gene might interact with endogenous vitamin D and gemcitabine treatment to determine improved patient survival. These results support evidence for a modulatory role of the vitamin D pathway for the survival of advanced pancreatic cancer patients.

Multiple Myeloma (MM) is an incurable hematologic malignancy characterized by abnormal proliferation of plasma cells. Interferon Regulatory Factor 4 (IRF4), a member of the interferon regulatory family of transcription factors, is central to the genesis of MM. IRF4 is highly expressed in B cells and plasma cells where it plays essential roles in controlling B cell to plasma cell differentiation and immunoglobulin class switching. Overexpression of IRF4 is found in MM patients' derived cells, often as a result of activating mutations or translocations, where it is required for their survival. In this review, we first describe the roles of IRF4 in B cells and plasma cells and then analyse the subversion of the IRF4 transcriptional network in MM. Moreover, we discuss current therapies for MM as well as direct targeting of IRF4 as a potential new therapeutic strategy.

Adult T cell leukemia/lymphoma (ATLL) is a frequently incurable disease associated with the human lymphotropic virus type I (HTLV-I). RNAi screening of ATLL lines revealed that their proliferation depends on BATF3 and IRF4, which cooperatively drive ATLL-specific gene expression. HBZ, the only HTLV-I encoded transcription factor that is expressed in all ATLL cases, binds to an ATLL-specific BATF3 super-enhancer and thereby regulates the expression of BATF3 and its downstream targets, including MYC. Inhibitors of bromodomain-and-extra-terminal-domain (BET) chromatin proteins collapsed the transcriptional network directed by HBZ and BATF3, and were consequently toxic for ATLL cell lines, patient samples, and xenografts. Our study demonstrates that the HTLV-I oncogenic retrovirus exploits a regulatory module that can be attacked therapeutically with BET inhibitors.

The clonal architecture of tumors plays a vital role in their pathogenesis and invasiveness; however, it is not yet clear how this clonality contributes to different malignancies. In this study we sought to address mutational intratumor heterogeneity (ITH) in adult T-cell leukemia/lymphoma (ATL). ATL is a malignancy with an incompletely understood molecular pathogenesis caused by infection with human T-cell leukemia virus type-1 (HTLV-1). To determine the clonal structure through tumor genetic diversity profiles, we investigated 142 whole-exome sequencing data of tumor and matched normal samples from 71 ATL patients. Based on SciClone analysis, the ATL samples showed a wide spectrum of modes over clonal/subclonal frequencies ranging from one to nine clusters. The average number of clusters was six across samples, but the number of clusters differed among different samples. Of these ATL samples, 94% had more than two clusters. Aggressive ATL cases had slightly more clonal clusters than indolent types, indicating the presence of ITH during earlier stages of disease. The known significantly mutated genes in ATL were frequently clustered together and possibly coexisted in the same clone. IRF4, CCR4, TP53, and PLCG1 mutations were almost clustered in subclones with a moderate variant allele frequency (VAF), whereas HLA-B, CARD11, and NOTCH1 mutations were clustered in subclones with lower VAFs. Taken together, these results show that ATL displays a high degree of ITH and a complex subclonal structure. Our findings suggest that clonal/subclonal architecture might be a useful measure for prognostic purposes and personalized assessment of the therapeutic response.

There is a significant difference in prognosis between the germinal center B-cell (GCB) and activated B-cell (ABC) subtypes of diffuse large B-cell lymphoma (DLBCL). However, the signaling pathways and driver genes involved in these disparate subtypes are ambiguous. This study integrated three cohort profile datasets, including 250 GCB samples and 250 ABC samples, to elucidate potential candidate hub genes and key pathways involved in these two subtypes. Differentially expressed genes (DEGs) were identified. After Gene Ontology functional enrichment analysis of the DEGs, protein-protein interaction (PPI) network and sub-PPI network analyses were conducted using the STRING database and Cytoscape software. Subsequently, the Oncomine database and the cBioportal online tool were employed to verify the alterations and differential expression of the 8 hub genes (MME, CD44, IRF4, STAT3, IL2RA, ETV6, CCND2, and CFLAR). Gene set enrichment analysis was also employed to identify the intersection of the key pathways (JAK-STAT, FOXO, and NF-

Primary effusion lymphoma (PEL) is an aggressive cancer with few treatment options. The immunomodulatory drugs (IMiDs) lenalidomide and pomalidomide have recently been shown to kill PEL cell lines, and lenalidomide is in clinical trials against PEL. IMiDs bind to the CRL4

Understanding the profile of oncogene and tumor suppressor gene mutations with their interactions and impact on the prognosis of multiple myeloma (MM) can improve the definition of disease subsets and identify pathways important in disease pathobiology. Using integrated genomics of 1273 newly diagnosed patients with MM, we identified 63 driver genes, some of which are novel, including

Rheumatoid arthritis patients often develop the diffuse large B-cell lymphoma subtype of methotrexate-associated lymphoproliferative disorder (DLBCL). We characterized the genomic profile and pathologic characteristics of 20 biopsies using an integrative approach. DLBCL was associated with extranodal involvement, a high/high-intermediate international prognostic index in 53% of cases, and responded to MTX withdrawal. The phenotype was nongerminal center B-cell in 85% of samples and Epstein-Barr encoding region positive (EBER) in 65%, with a high proliferation index and intermediate MYC expression levels. The immune microenvironment showed high numbers of CD8 cytotoxic T lymphocytes and CD163 M2 macrophages with an (CD163/CD68) M2 ratio of 3.6. Its genomic profile was characterized by 3p12.1-q25.31, 6p25.3, 8q23.1-q24.3, and 12p13.33-q24.33 gains, 6q22.31-q24.1 and 13q21.33-q34 losses, and 1p36.11-p35.3 copy neutral loss-of-heterozygosity. This profile was closer to nongerminal center B-cell DLBCL not-otherwise-specified, but with characteristic 3q, 12q, and 20p gains and lower 9p losses (P<0.05). We successfully verified array results using fluorescent DNA in situ hybridization on PLOD2, MYC, WNT1, and BCL2. Protein immunohistochemistry revealed that DLBCL expressed high IRF4 (6p25.3) and SELPLG (12q24.11) levels, intermediate TNFRSF14 (1p36.32; the exons 1 to 3 were unmutated), BTLA (3q13.2), PLOD2 (3q24), KLHL6 (3q27.1), and MYC (8q24.21) levels, and low AICDA (12p13.31) and EFNB2 (13q33.3) levels. The correlation between the DNA copy number and protein immunohistochemistry was confirmed for BTLA, PLOD2, and EFNB2. The characteristics of EBER versus EBER cases were similar, with the exception of specific changes: EBER cases had higher numbers of CD163 M2 macrophages and FOXP3 regulatory T lymphocytes, high programmed cell death 1 ligand 1 expression levels, slightly fewer genomic changes, and 3q and 4p focal gains. In conclusion, DLBCL has a characteristic genomic profile with 3q and 12 gains, 13q loss, different expression levels of relevant pathogenic biomarkers, and a microenvironment with high numbers of cytotoxic T lymphocytes and M2 macrophages.

Diffuse large B-cell lymphoma (DLBCL) is subdivided by gene expression analysis (GEP) into two molecular subtypes named germinal center B-cell-like (GCB) and activated B-cell-like (ABC) after their putative cell-of-origin (COO). Determination of the COO is considered mandatory in any new-diagnosed DLBCL, not otherwise specified according to the updated WHO classification. Despite the fact that pathologists are free to choose the method for COO classification, immunohistochemical (IHC) assays are most widely used. However, to the best of our knowledge, no round-robin test to evaluate the interlaboratory variability has been published so far. Eight hematopathology laboratories participated in an interlaboratory test for COO classification of 10 DLBCL tumors using the IHC classifier comprising the expression of CD10, BCL6, and MUM1 (so-called Hans classifier). The results were compared with GEP for COO signature and, in a subset, with results obtained by image analysis. In 7/10 cases (70%), at least seven laboratories assigned a given case to the same COO subtype (one center assessed one sample as not analyzable), which was in agreement with the COO subtype determined by GEP. The results in 3/10 cases (30%) revealed discrepancies between centers and/or between IHC and GEP subtype. Whereas the CD10 staining results were highly reproducible, staining for MUM1 was inconsistent in 50% and for BCL6 in 40% of cases. Image analysis of 16 slides stained for BCL6 (N = 8) and MUM1 (N = 8) of the two cases with the highest disagreement in COO classification were in line with the score of the pathologists in 14/16 stainings analyzed (87.5%). This study describes the first round-robin test for COO subtyping in DLBCL using IHC and demonstrates that COO classification using the Hans classifier yields consistent results among experienced hematopathologists, even when variable staining protocols are used. Data from this small feasibility study need to be validated in larger cohorts.

Interferon regulatory factor (IRF) 4 and the proto-oncogene c-Rel cooperate in growth and antiviral drug resistance of adult T-cell leukemia/lymphoma (ATLL). To elucidate the target of IRF4 and c-Rel in ATLL, we determined the simultaneous binding sites of IRF4 and c-Rel using ChIP-seq technology. Nine genes were identified within 2 kb of binding sites, including MIR3662. Expression of miR-3662 was regulated by IRF4, and to a lesser extent by c-Rel. Cell proliferation was inhibited by knockdown of miR-3662 and expression of miR-3662 was correlated with antiviral drug resistance in ATLL cell lines. Thus, miR-3662 represents a target for therapies against ATLL.

Rearrangements involving interferon regulatory factor 4 (IRF4) gene has been recently described in a subtype of diffuse large B-cell lymphoma (DLBCL). They occur in a typical clinical setting of a pediatric age group, predominantly with tonsillar mass, usually as a low-stage disease and with good response to chemotherapy. Histomorphologically, they show nodular/follicular architecture with diffuse strong immunopositivity for multiple myeloma oncogene 1. Here, the authors describe one such unusual case of large B-cell lymphoma with IRF4 gene rearrangement in a young child with the unusual location of inguinal region and detailed pathological (histological, immunohistochemical, and molecular) findings.

AIM: CD30+ diffuse large B-cell lymphoma (DLBCL) has emerged as a new immunophenotypic variant of
METHODS: A total of 241 patients with
RESULTS: Using a >0% threshold, CD30 expression was detected in approximately 10% patient with
CONCLUSION: CD30+ DLBCL may be a subset of

Multiple myeloma (MM) is a biologically heterogeneous malignancy, however, the mechanisms underlying this complexity are incompletely understood. We report an analysis of the whole-genome sequencing of 765 MM patients from CoMMpass. By employing promoter capture Hi-C in naïve B-cells, we identify cis-regulatory elements (CREs) that represent a highly enriched subset of the non-coding genome in which to search for driver mutations. We identify regulatory regions whose mutation significantly alters the expression of genes as candidate non-coding drivers, including copy number variation (CNV) at CREs of MYC and single-nucleotide variants (SNVs) in a PAX5 enhancer. To better inform the interplay between non-coding driver mutations with other driver mechanisms, and their respective roles in oncogenic pathways, we extended our analysis identifying coding drivers in 40 genes, including 11 novel candidates. We demonstrate the same pathways can be targeted by coding and non-coding mutations; exemplified by IRF4 and PRDM1, along with BCL6 and PAX5, genes that are central to plasma cell differentiation. This study reveals new insights into the complex genetic alterations driving MM development and an enhanced understanding of oncogenic pathways.

Transcription factor AP-1 is constitutively activated and IRF4 drives growth and survival in ALK

A linear progression model of follicular lymphomas (FL) FL1, FL2 and FL3A has been favored, since FL3A often co-exist with an FL1/2 component. FL3B, in contrast, is thought to be more closely related to diffuse large B-cell lymphoma (DLBCL), and both are often simultaneously present in one tumor (DLBCL/FL3B). To obtain more detailed insights into follicular lymphoma progression, a comprehensive analysis of a well-defined set of FL1/2 (n=22), FL3A (n=16), FL3B (n=6), DLBCL/FL3B (n=9), and germinal center B-cell-type diffuse large B-cell lymphoma (n=45) was undertaken using gene expression profiling, immunohistochemical stainings and genetic analyses by fluorescence

Deregulation of several microRNAs (miRs) can influence critical developmental checkpoints during hematopoiesis as well as cell functions, eventually leading to the development of autoimmune disease or cancer. We found that miR-125b is expressed in bone marrow multipotent progenitors and myeloid cells but shut down in the B-cell lineage, and the gene encoding miR-125b lacked transcriptional activation markers in B cells. To understand the biological importance of the physiological silencing of miR-125b expression in B cells, we drove its expression in the B-cell lineage and found that dysregulated miR-125b expression impaired egress of immature B cells from the bone marrow to peripheral blood. Such impairment appeared to be mediated primarily by inhibited expression of the sphingosine-1-phosphate receptor 1 (S1PR1). Enforced expression of S1PR1 or clustered regularly interspaced short palindromic repeats/Cas9-mediated genome editing of the miR-125b targeting site in the S1PR1 3' untranslated region rescued the miR-125b-mediated defect in B-cell egress. In addition to impaired B-cell egress, miR-125b dysregulation initially reduced pre-B-cell output but later induced pre-B-cell lymphoma/leukemia in mice. Genetic deletion of IRF4 was found in miR-125b-induced B-cell cancer, but its role in oncogenic miR-125b-induced B-cell transformation is still unknown. Here, we further demonstrated an interaction of the effects of miR-125b and IRF4 in cancer induction by showing that miR125b-induced B-cell leukemia was greatly accelerated in IRF4 homozygous mutant mice. Thus, we conclude that physiological silencing of miR-125b is required for normal B-cell development and also acts as a mechanism of cancer suppression.

The human T-cell leukemia virus-1 (HTLV-1) oncoprotein Tax drives cell proliferation and resistance to apoptosis early in the pathogenesis of adult T-cell leukemia (ATL). Subsequently, probably as a result of specific immunoediting, Tax expression is down-regulated and functionally replaced by somatic driver mutations of the host genome. Both amplification and point mutations of interferon regulatory factor 4 (IRF4) have been previously detected in ATL., K59R is the most common single-nucleotide variation of IRF4 and is found exclusively in ATL. High-throughput whole-exome sequencing revealed recurrent activating genetic alterations in the T-cell receptor, CD28, and NF-κB pathways. We found that IRF4, which is transcriptionally activated downstream of these pathways, is frequently mutated in ATL. IRF4 RNA, protein, and IRF4 transcriptional targets are uniformly elevated in HTLV-1-transformed cells and ATL cell lines, and IRF4 was bound to genomic regulatory DNA of many of these transcriptional targets in HTLV-1-transformed cell lines. We further noted that the K59R IRF4 mutant is expressed at higher levels in the nucleus than WT IRF4 and is transcriptionally more active. Expression of both WT and the K59R mutant of IRF4 from a constitutive promoter in retrovirally transduced murine bone marrow cells increased the abundance of T lymphocytes but not myeloid cells or B lymphocytes in mice. IRF4 may represent a therapeutic target in ATL because ATL cells select for a mutant of IRF4 with higher nuclear expression and transcriptional activity, and overexpression of IRF4 induces the expansion of T lymphocytes

BACKGROUND: Melanoma and prostate cancer may share risk factors. This study examined the association between serum PSA levels, which is a risk factor for prostate cancer, and variants in some melanoma-associated pigmentary genes.
METHODS: We studied participants, all aged 70+ years, in the Concord Health and Ageing in Men Project who had no history of prostatitis or received treatment for prostate disease (n = 1033). We genotyped variants in MC1R (rs1805007, rs1805008), ASIP (rs4911414, rs1015362), SLC45A2 (rs28777, rs16891982), IRF4 (rs12203592), TYRP1 (rs1408799), TYR (rs1126809, rs1042602), SLC24A2 (rs12896399), and OCA2 (rs7495174). Generalised linear dominant models with Poisson distribution, log link functions and robust variance estimators estimated adjusted percentage differences (%PSA) in mean serum PSA levels (ng/mL) between variant and wildtype (0%PSA = reference) genotypes, adjusting for age, body mass index, serum 25OHD levels and birth regions (Australia or New Zealand (ANZ), Europe or elsewhere).
RESULTS: Serum PSA levels were strongly associated with advancing age and birth regions: mean PSA levels were lower in Europe-born (-29.7%) and elsewhere-born (-11.7%) men than ANZ-born men (reference). Lower %PSA was observed in men with variants in SLC45A2: rs28777 (-19.6;95%CI: -33.5, -2.7), rs16891982 (-17.3;95%CI:-30.4,-1.7) than in wildtype men (reference). There were significant interactions between birth regions and PSA levels in men with variants in MC1R (rs1805007; p-interaction = 0.0001) and ASIP (rs4911414; p-interaction = 0.007). For these genes %PSA was greater in ANZ-born men and lower in Europe- and elsewhere-born men with the variant than it was in wildtype men. In a post hoc analysis, serum testosterone levels were increased in men with MC1R rs1805007 and serum dihydrotestosterone in men with ASIP rs1015362.
CONCLUSION: Men with SNPs in SLC45A2, who have less sun sensitive skin, have lower PSA levels. Men with SNPs in MC1R and ASIP, who have more sun sensitive skin, and were born in ANZ, have higher PSA levels. Androgens may modify these apparent associations of pigmentary genes and sun exposure with PSA levels.
IMPACT: PSA levels and possibly prostate cancer risk may vary with sun sensitivity and sun exposure, the effects of which might be modified by androgen levels.

BACKGROUND: Multiple myeloma (MM) is the second most common hematologic malignancy. Aberrant epigenetic modifications have been reported in MM and could be promising therapeutic targets. As response rates are overall limited but deep responses occur, it is important to identify those patients who could indeed benefit from epigenetic-targeted therapy.
METHODS: Since HDACi and DNMTi combination have potential therapeutic value in MM, we aimed to build a GEP-based score that could be useful to design future epigenetic-targeted combination trials. In addition, we investigated the changes in GEP upon HDACi/DNMTi treatment.
RESULTS: We report a new gene expression-based score to predict MM cell sensitivity to the combination of DNMTi/HDACi. A high Combo score in MM patients identified a group with a worse overall survival but a higher sensitivity of their MM cells to DNMTi/HDACi therapy compared to a low Combo score. In addition, treatment with DNMTi/HDACi downregulated IRF4 and MYC expression and appeared to induce a mature BMPC plasma cell gene expression profile in myeloma cell lines.
CONCLUSION: In conclusion, we developed a score for the prediction of primary MM cell sensitivity to DNMTi/HDACi and found that this combination could be beneficial in high-risk patients by targeting proliferation and inducing maturation.