Transcriptome sequencing of archived lymphoma specimens is feasible and clinically relevant using exome capture technology.

Formalin-fixed, paraffin-embedded (FFPE) specimens are an underutilized resource in medical research, particularly in the setting of transcriptome sequencing, as RNA from these samples is often degraded. We took advantage of an exome capture-based RNA-sequencing protocol to explore global gene expression in paired fresh-frozen (FF) and FFPE samples from 16 diffuse large B-cell lymphoma (DLBCL) patients. While FFPE samples generated fewer mapped reads compared to their FF counterparts, these reads captured the same library complexity and had a similar number of genes expressed on average. Furthermore, gene expression demonstrated a high correlation when comparing housekeeping genes only or across the entire transcriptome (r = 0.99 for both comparisons). Differences in gene expression were primarily seen in lowly expressed genes and genes with small or large coding sequences. Using cell-of-origin classifiers and clinically relevant gene expression signatures for DLBCL, FF, and FFPE samples from the same biopsy paired nearly perfectly in clustering analysis. This was further confirmed in a validation cohort of 50 FFPE DLBCL samples. In summary, we found the biological differences between tumors to be far greater than artifacts created as a result of degraded RNA. We conclude that exome capture transcriptome sequencing data from archival samples can confidently be used for cell-of-origin classification of DLBCL samples.

PD-L1 and IDO1 are potential targets for treatment in patients with primary diffuse large B-cell lymphoma of the CNS.

BACKGROUND: Programmed cell death 1 (PD-1) and its ligands PD-L1 and PD-L2, as well as Indoleamine 2,3-deoxygenase (IDO1) can be expressed both by tumor and microenvironmental cells and are crucial for tumor immune escape. We aimed to evaluate the role of PD-1, its ligands and IDO1 in a cohort of patients with primary diffuse large B-cell lymphoma of the CNS (PCNSL). MATERIAL AND METHODS: Tissue microarrays (TMAs) were constructed in 45 PCNSL cases. RNA extraction from whole tissue sections and RNA sequencing were successfully performed in 33 cases. Immunohistochemical stainings for PD-1, PD-L1/paired box protein 5 (PAX-5), PD-L2/PAX-5 and IDO1, and Epstein-Barr virus encoding RNA (EBER) in situ hybridization were analyzed. RESULTS: High proportions of PD-L1 and PD-L2 positive tumor cells were observed in 11% and 9% of cases, respectively. High proportions of PD-L1 and PD-L2 positive leukocytes were observed in 55% and 51% of cases, respectively. RNA sequencing revealed that gene expression of IDO1 was high in patients with high proportion of PD-L1 positive leukocytes (p = .01). Protein expression of IDO1 in leukocytes was detected in 14/45 cases, in 79% of these cases a high proportion of PD-L1 positive leukocytes was observed. Gene expression of IDO1 was high in EBER-positive cases (p = .0009) and protein expression of IDO1 was detected in five of six EBER-positive cases. CONCLUSION: Our study shows a significant association between gene and protein expression of IDO1 and protein expression of PD-L1 in the tumor microenvironment of PCNSL, possibly of importance for prediction of response to immunotherapies.

Genetic basis of PD-L1 overexpression in diffuse large B-cell lymphomas.

Diffuse large B-cell lymphoma (DLBCL) is one of the most common and aggressive types of B-cell lymphoma. Deregulation of proto-oncogene expression after a translocation, most notably to the immunoglobulin heavy-chain locus (IGH), is one of the hallmarks of DLBCL. Using whole-genome sequencing analysis, we have identified the PD-L1/PD-L2 locus as a recurrent translocation partner for IGH in DLBCL. PIM1 and TP63 were also identified as novel translocation partners for PD-L1/PD-L2 Fluorescence in situ hybridization was furthermore used to rapidly screen an expanded DLBCL cohort. Collectively, a subset of samples was found to be affected by gains (12%), amplifications (3%), and translocations (4%) of the PD-L1/PD-L2 locus. RNA sequencing data coupled with immunohistochemistry revealed that these cytogenetic alterations correlated with increased expression of PD-L1 but not of PD-L2 Moreover, cytogenetic alterations affecting the PD-L1/PD-L2 locus were more frequently observed in the non-germinal center B cell-like (non-GCB) subtype of DLBCL. These findings demonstrate the genetic basis of PD-L1 overexpression in DLBCL and suggest that treatments targeting the PD-1-PD-L1/PD-L2 axis might benefit DLBCL patients, especially those belonging to the more aggressive non-GCB subtype.

Expression of possible targets for new proteasome inhibitors in diffuse large B-cell lymphoma.

OBJECTIVES: Investigating expression of possible targets for proteasome inhibitors in patients with diffuse large B-cell lymphoma (DLBCL) and correlating the findings to clinical parameters and outcome. METHODS: Tumour material from 92 patients with DLBCL treated with either R-CHOP like (n = 69) or CHOP like (n = 23) regimens were stained for possible targets of proteasome inhibitors. RESULTS: The primary target molecule of bortezomib, proteasome subunit beta, type 5 (PSMB5), was not detected in the tumour cells in any of the cases but showed an abundant expression in cells in the microenvironment. However, the deubiquitinases (DUBs) of the proteasome, the ubiquitin carboxyl-terminal hydrolase L5 (UCHL5) and the ubiquitin specific peptidase 14 (USP14), were detected in the cytoplasm of the tumour cells in 77% and 74% of the cases, respectively. The adhesion regulating molecule 1 (ADRM1) was detected in 98% of the cases. There was no correlation between the expression of any of the studied markers and clinical outcome or GC/non-GC phenotype. CONCLUSIONS: We suggest that UCHL5 and/or USP14 should be further evaluated as new targets for proteasome inhibitors in DLBCL. The lack of expression of PSMB5 on the tumour cells might provide an explanation of the relatively poor results of bortezomib in DLBCL.

Coding variants at hexa-allelic amino acid 13 of HLA-DRB1 explain independent SNP associations with follicular lymphoma risk.

Non-Hodgkin lymphoma represents a diverse group of blood malignancies, of which follicular lymphoma (FL) is a common subtype. Previous genome-wide association studies (GWASs) have identified in the human leukocyte antigen (HLA) class II region multiple independent SNPs that are significantly associated with FL risk. To dissect these signals and determine whether coding variants in HLA genes are responsible for the associations, we conducted imputation, HLA typing, and sequencing in three independent populations for a total of 689 cases and 2,446 controls. We identified a hexa-allelic amino acid polymorphism at position 13 of the HLA-DR beta chain that showed the strongest association with FL within the major histocompatibility complex (MHC) region (multiallelic p = 2.3 × 10⁻¹5). Out of six possible amino acids that occurred at that position within the population, we classified two as high risk (Tyr and Phe), two as low risk (Ser and Arg), and two as moderate risk (His and Gly). There was a 4.2-fold difference in risk (95% confidence interval = 2.9-6.1) between subjects carrying two alleles encoding high-risk amino acids and those carrying two alleles encoding low-risk amino acids (p = 1.01 × 10⁻¹4). This coding variant might explain the complex SNP associations identified by GWASs and suggests a common HLA-DR antigen-driven mechanism for the pathogenesis of FL and rheumatoid arthritis.

A population-based study of cellular markers in R-CHOP treated diffuse large B-cell lymphoma patients.

AIM: To determine the prognostic significance of co-expression of MYC, BCL-2 and BCL-6 proteins in combination with other biomarkers and clinical characteristics within a population-based cohort of diffuse large B-cell lymphoma (DLBCL) patients uniformly treated with R-CHOP. PATIENTS AND METHODS: The immunohistochemical (IHC) expression of CD10, BCL-2, BCL-6, MUM1, MYC, CD5, CD30, Ki-67 and p53 was evaluated in a retrospective, population-based study comprising 188 DLBCL patients treated with R-CHOP and diagnosed in Sweden between 2002 and 2012. RESULTS: Patients had a median age at diagnosis of 64 years (26-85 years) with a male:female ratio of 1.4:1. Approximately half (52%) of the patients presented with an International Prognostic Index (IPI) age adjusted (IPIaa) ≥ 2. Median follow-up time was 51 months (range 0.4-158) and the five-year lymphoma-specific survival (LSS) was 76%, five-year overall survival (OS) was 65% and five-year progression-free survival (PFS) was 61%. A high Ki-67 value was found in 59% of patients, while p53 overexpression was detected in 12% of patients and MYC, BCL-2 and BCL-6 expression were detected in 42%, 55% and 74% of patients, respectively. IPIaa ≥2 (p = 0.002), Ki-67 ≥ 70% (p = 0.04) and p53 overexpression ≥50% (p = 0.02) were associated with inferior LSS and OS. Co-expression of both MYC (>40%) and BCL-2 (>70%) proteins was detected in 27% of patients and correlated with a significantly inferior LSS (p = 0.0002), OS (p = 0.009) and PFS (p = 0.03). In addition, triple expression of MYC, BCL-2 and BCL-6, also correlated with a significantly inferior LSS (p = 0.02). CONCLUSION: Concurrent expression of MYC and BCL-2 proteins, as detected by IHC, was strongly associated with an inferior survival in DLBCL patients treated with R-CHOP. Other markers affecting survival were triple expression of MYC, BCL-2 and BCL-6, IPIaa, high Ki-67 and p53 overexpression.

Male gender is an adverse risk factor only in young patients with diffuse large B-cell lymphoma - a Swedish population-based study.

BACKGROUND: Diffuse large B-cell lymphoma (DLBCL) is a heterogeneous group of B-cell lymphomas. Five clinical adverse risk factors are merged into the International Prognostic Index (IPI), which is the major tool for prognostication. In contrast to Hodgkin's lymphoma, gender is not considered as an adverse risk factor for DLBCL patients. As we clinically had observed a very good survival rate in young female patients we hypothesised that there was a gender difference in survival due to the hormonal status of the patient. MATERIAL AND METHODS: We conducted a registry-based retrospective cohort study of all Swedish DLBCL patients diagnosed between 2000 and 2013, to evaluate the impact of gender for survival from DLBCL. RESULTS: In total, 7166 patients were included for further analysis. No survival difference was found between the genders when the entire population was analysed. However, analysis of 880 young patients of pre-menopausal age (i.e. 52 years) revealed that women had a longer survival compared to men of the same age group (p=0.007). This was not found for patients older than menopausal age. In a relative survival multifactorial model adjusted for stage, ECOG performance status, serum lactate dehydrogenase and two or more extranodal sites, male gender was found to be an adverse risk factor for patients younger than 52 years (RR 1.51, 95% CI 1.14-1.88), but not for older patients (RR 0.99, 95% CI 0.89-1.10). CONCLUSION: This is one of the largest population-based studies of DLBCL presented to date. Most interestingly, we found male gender to be a significant adverse risk factor compared to fertile women whereas we found no survival differences between genders in the older sub-population.

Amplification of 2p as a genomic marker for transformation in lymphoma.

To outline further genetic mechanisms of transformation from follicular lymphoma (FL) to diffuse large B-cell lymphoma (DLBCL), we have performed whole genome array-CGH in 81 tumors from 60 patients [29 de novo DLBCL (dnDLBCL), 31 transformed DLBCL (tDLBCL), and 21 antecedent FL]. In 15 patients, paired tumor samples (primary FL and a subsequent tDLBCL) were available, among which three possessed more than two subsequent tumors, allowing us to follow specific genetic alterations acquired before, during, and after the transformation. Gain of 2p15-16.1 encompassing, among others, the REL, BCL11A, USP34, COMMD1, and OTX1 genes was found to be more common in the tDLBCL compared with dnDLBCL (P < 0.001). Furthermore, a high-level amplification of 2p15-16.1 was also detected in the FL stage prior to transformation, indicating its importance during the transformation event. Quantitative real-time PCR showed a higher level of amplification of REL, USP34, and COMMD1 (all involved in the NFκΒ-pathway) compared with BCL11A, which indicates that the altered genes disrupting the NFκΒ pathway may be the driver genes of transformation rather than the previously suggested BCL11A. Moreover, a 17q21.33 amplification was exclusively found in tDLBCL, never in FL (P < 0.04) or dnDLBCL, indicating an upregulation of genes of importance during the later phase of transformation. Taken together, our study demonstrates potential genomic markers for disease progression to clinically more aggressive forms. We also confirm the importance of the TP53-, CDKN2A-, and NFκΒ-pathways for the transformation from FL to DLBCL.

The MDM2 polymorphism SNP309 is associated with clinical characteristics and outcome in diffuse large B-cell lymphoma.

INTRODUCTION: The murine double minute 2 (MDM2) gene encodes a regulatory protein of the p53 pathway. A single nucleotide polymorphism (T to G change) at position 309 (SNP309) in the promotor region of MDM2 affects the transcription activity of MDM2 and has been found to be a negative prognostic marker in several cancers. PATIENTS AND METHODS: In this study, the MDM2 SNP309 polymorphism was analysed in 201 patients with diffuse large B-cell lymphoma and analysed in relation to clinical characteristics and prognosis. RESULTS: Patients homozygous for SNP309T had a significantly longer overall survival, lymphoma-specific survival and disease-free survival (P = 0.002; 0.004 and 0.006 respectively) compared to patients carrying a G allele. The longer overall survival was seen in the subgroup of patients not treated with Rituximab, however, not for Rituximab-treated patients (P = 0.01 and 0.2 respectively). The group homozygous for the T allele also had lower age at diagnosis, a tendency towards lower aaIPI and a significantly lower proportion of patients with p53 aberrations compared to the group including at least one G allele. However, the survival differences persisted even after removal of cases with known p53 aberrations from the analysis. CONCLUSION: Polymorphism in MDM2 SNP309 could be correlated to some clinical characteristics and for patients not treated with immunotherapy, a G allele was correlated to poor survival, whereas no survival differences were found for patients treated with Rituximab. Herewith, we provide additional information about Diffuse large B-cell Lymphoma (DLBCL) biology and highlight the importance of evaluation of molecular markers in relation to treatment.

Genetic and transcriptomic analyses of diffuse large B-cell lymphoma patients with poor outcomes within two years of diagnosis.

Despite the improvements in clinical outcomes for DLBCL, a significant proportion of patients still face challenges with refractory/relapsed (R/R) disease after receiving first-line R-CHOP treatment. To further elucidate the underlying mechanism of R/R disease and to develop methods for identifying patients at risk of early disease progression, we integrated clinical, genetic and transcriptomic data derived from 2805 R-CHOP-treated patients from seven independent cohorts. Among these, 887 patients exhibited R/R disease within two years (poor outcome), and 1918 patients remained in remission at two years (good outcome). Our analysis identified four preferentially mutated genes (TP53, MYD88, SPEN, MYC) in the untreated (diagnostic) tumor samples from patients with poor outcomes. Furthermore, transcriptomic analysis revealed a distinct gene expression pattern linked to poor outcomes, affecting pathways involved in cell adhesion/migration, T-cell activation/regulation, PI3K, and NF-κB signaling. Moreover, we developed and validated a 24-gene expression score as an independent prognostic predictor for treatment outcomes. This score also demonstrated efficacy in further stratifying high-risk patients when integrated with existing genetic or cell-of-origin subtypes, including the unclassified cases in these models. Finally, based on these findings, we developed an online analysis tool ( https://lymphprog.serve.scilifelab.se/app/lymphprog ) that can be used for prognostic prediction for DLBCL patients.

Sex- and Female Age-Dependent Differences in Gene Expression in Diffuse Large B-Cell Lymphoma-Possible Estrogen Effects.

For most lymphomas, including diffuse large B-cell lymphoma (DLBCL), the male incidence is higher, and the prognosis is worse compared to females. The reasons are unclear; however, epidemiological and experimental data suggest that estrogens are involved. With this in mind, we analyzed gene expression data from a publicly available cohort (EGAD00001003600) of 746 DLBCL samples based on RNA sequencing. We found 1293 genes to be differentially expressed between males and females (adj. p-value < 0.05). Few autosomal genes and pathways showed common sex-regulated expression between germinal center B-cell (GCB) and activated B-cell lymphoma (ABC) DLBCL. Analysis of differentially expressed genes between pre- vs. postmenopausal females identified 208 GCB and 345 ABC genes, with only 5 being shared. When combining the differentially expressed genes between females vs. males and pre- vs. postmenopausal females, nine putative estrogen-regulated genes were identified in ABC DLBCL. Two of them, NR4A2 and MUC5B, showed induced and repressed expression, respectively. Interestingly, NR4A2 has been reported as a tumor suppressor in lymphoma. We show that ABC DLBCL females with a high NR4A2 expression showed better survival. Inversely, MUC5B expression causes a more malignant phenotype in several cancers. NR4A2 and MUC5B were confirmed to be estrogen-regulated when the ABC cell line U2932 was grafted to mice. The results demonstrate sex- and female reproductive age-dependent differences in gene expression between DLBCL subtypes, likely due to estrogens. This may contribute to the sex differences in incidence and prognosis.

ADAR1-mediated RNA editing promotes B cell lymphomagenesis.

Diffuse large B cell lymphoma (DLBCL) is one of the most common types of aggressive lymphoid malignancies. Here, we explore the contribution of RNA editing to DLBCL pathogenesis. We observed that DNA mutations and RNA editing events are often mutually exclusive, suggesting that tumors can modulate pathway outcomes by altering sequences at either the genomic or the transcriptomic level. RNA editing targets transcripts within known disease-driving pathways such as apoptosis, p53 and NF-κB signaling, as well as the RIG-I-like pathway. In this context, we show that ADAR1-mediated editing within MAVS transcript positively correlates with MAVS protein expression levels, associating with increased interferon/NF-κB signaling and T cell exhaustion. Finally, using targeted RNA base editing tools to restore editing within MAVS 3'UTR in ADAR1-deficient cells, we demonstrate that editing is likely to be causal to an increase in downstream signaling in the absence of activation by canonical nucleic acid receptor sensing.

Estrogen Receptor ß (ESR2) Transcriptome and Chromatin Binding in a Mantle Cell Lymphoma Tumor Model Reveal the Tumor-Suppressing Mechanisms of Estrogens.

Mantle cell lymphoma (MCL) is a non-Hodgkin lymphoma with one of the highest male-to-female incidence ratios. The reason for this is not clear, but epidemiological as well as experimental data have suggested a role for estrogens, particularly acting through estrogen receptor ß (ESR2). To study the ESR2 effects on MCL progression, MCL cells sensitive and resistant to the Bruton tyrosine kinase inhibitor ibrutinib were grafted to mice and treated with the ESR2-selective agonist diarylpropionitrile (DPN). The results showed that the DPN treatment of mice grafted with both ibrutinib-sensitive and -resistant MCL tumors resulted in impaired tumor progression. To identify the signaling pathways involved in the impaired tumor progression following ESR2 agonist treatment, the transcriptome and ESR2 binding to target genes were investigated by genome-wide chromatin immunoprecipitation in Granta-519 MCL tumors. DPN-regulated genes were enriched in several biological processes that included cell-cell adhesion, endothelial-mesenchymal transition, nuclear factor-kappaB signaling, vasculogenesis, lymphocyte proliferation, and apoptosis. In addition, downregulation of individual genes, such as SOX11 and MALAT1, that play a role in MCL progression was also observed. Furthermore, the data suggested an interplay between the lymphoma cells and the tumor microenvironment in response to the ESR2 agonist. In conclusion, the results clarify the mechanisms by which estrogens, via ESR2, impair MCL tumor progression and provide a possible explanation for the sex-dependent difference in incidence. Furthermore, targeting ESR2 with a selective agonist may be an additional option when considering the treatment of both ibrutinib-sensitive and -resistant MCL tumors.

The dual role of CD70 in B-cell lymphomagenesis.

BACKGROUND: CD70 is a costimulatory molecule that is transiently expressed on a small set of activated lymphocytes and is involved in T-cell-mediated immunity. However, the role of CD70 in B-cell malignancies remains controversial. METHODS: We investigated the clinical relevance of CD70 genetic alterations and its protein expression in two diffuse large B-cell lymphoma (DLBCL) cohorts with different ethnic backgrounds. We also performed transcriptomic analysis to explore the role of CD70 alterations in tumour microenvironment. We further tested the blockade of CD70 in combination with PD-L1 inhibitor in a murine lymphoma model. RESULTS: We showed that CD70 genetic aberrations occurred more frequently in the Chinese DLBCL cohort (56/233, 24.0%) than in the Swedish cohort (9/84, 10.8%), especially in those with concomitant hepatitis B virus (HBV) infection. The CD70 genetic changes in DLBCL resulted in a reduction/loss of protein expression and/or CD27 binding, which might impair T cell priming and were independently associated with poor overall survival. Paradoxically, we observed that over-expression of CD70 protein was also associated with a poor treatment response, as well as an advanced disease stage and EBV infection. More exhausted CD8+ T cells were furthermore identified in CD70 high-expression DLBCLs. Finally, in a murine lymphoma model, we demonstrated that blocking the CD70/CD27 and/or PD1/PD-L1 interactions could reduce CD70+ lymphoma growth in vivo, by directly impairing the tumour cell proliferation and rescuing the exhausted T cells. CONCLUSIONS: Our findings suggest that CD70 can play a role in either tumour suppression or oncogenesis in DLBCL, likely via distinct immune evasion mechanisms, that is, impairing T cell priming or inducing T cell exhaustion. Characterisation of specific dysfunction of CD70 in DLBCL may thus provide opportunities for the development of novel targeted immuno-therapeutic strategies.

Does temperature regime govern the establishment of Heterobasidion annosum in Scandinavia?

We explored the reasons underlying the biogeographic distribution patterns of the economically important, wood-rotting basidiomycete Heterobasidion annosum in Sweden. Despite the commonness of suitable host trees, Heterobasidion annosum has not been recorded in the north of Sweden, whereas its relative, H. parviporum, is present throughout the country. To test the hypothesis that H. annosum has not spread to the north because of the effect of climate, mainly differences in the general temperature regime, we inoculated Norway spruce stumps and standing trees with H. annosum and H. parviporum at six field sites, three in the south and three in the north of Sweden. Three strains of both species were used in random combinations, so that each selected stump and tree was inoculated with both species at the same time. At 2 and 10 months after the inoculations, we compared the frequencies of detection of H. annosum and H. parviporum colonies at different distances from inoculation points in the stumps and in trees. The H. annosum colonies were detected only infrequently on disks cut from the inoculated stumps (0-4% of re-isolations) in both areas, whereas H. parviporum was detected much more frequently (26-47% of re-isolations). In standing trees, colonies belonging to H. annosum could be detected up to 210 cm (south) and 80 cm (north) and those belonging to H. parviporum up to 210 cm (south) and 140 cm (north) above the inoculation points. Our results suggest that difference in temperature regime does not provide an explanation for the distribution limit of H. annosum.

Identification of uniquely expressed transcription factors in highly purified B-cell lymphoma samples.

Transcription factors (TFs) are critical for B-cell differentiation, affecting gene expression both by repression and transcriptional activation. Still, this information is not used for classification of B-cell lymphomas (BCLs). Traditionally, BCLs are diagnosed based on a phenotypic resemblance to normal B-cells; assessed by immunohistochemistry or flow cytometry, by using a handful of phenotypic markers. In the last decade, diagnostic and prognostic evaluation has been facilitated by global gene expression profiling (GEP), providing a new powerful means for the classification, prediction of survival, and response to treatment of lymphomas. However, most GEP studies have typically been performed on whole tissue samples, containing varying degrees of tumor cell content, which results in uncertainties in data analysis. In this study, global GEP analyses were performed on highly purified, flow-cytometry sorted tumor-cells from eight subgroups of BCLs. This enabled identification of TFs that can be uniquely associated to the tumor cells of chronic lymphocytic leukemia (CLL), diffuse large B-cell lymphoma (DLBCL), follicular lymphoma (FL), hairy cell leukemia (HCL), and mantle cell lymphoma (MCL). The identified transcription factors influence both the global and specific gene expression of the BCLs and have possible implications for diagnosis and treatment.

Marginal zone lymphoma expression of histidine-rich glycoprotein correlates with improved survival.

Purpose: The abundant hepatocyte-expressed plasma protein histidine-rich glycoprotein (HRG) enhances antitumor immunity by polarizing inflammatory and immune cells in several mouse models, however, the clinical relevance of HRG in human cancer is poorly explored. The expression and role of HRG in human B-cell lymphomas was investigated in order to find new tools for prognosis and treatment. Findings: Immunohistochemical (IHC) analysis and RNA hybridization of tissue microarrays showed that (i) HRG was expressed by tumor cells in marginal zone lymphoma (MZL), in 36% of 59 cases. Expression was also detected in follicular lymphoma (22%), mantle cell lymphoma (19%), and indiffuse large B-cell lymphoma (DLBCL;5%) while primary CNS lymphoma (PCNSL) lacked expression of HRG. (ii) MZL patients positive for HRG showed a superior overall survival outcome (HR = 0.086, 95% CI = 0.014-0.518, P-value = .007), indicating a protective role for HRG independent of stage, age and sex. (iii) HRG-expressing MZL displayed significantly increased transcript and protein levels of the host defense peptide alpha defensin 1. In addition, global transcript analyses showed significant changes in gene ontology terms relating to immunity and inflammation, however, infiltration of immune and inflammatory cells detected by IHC was unaffected by HRG expression. Conclusion: HRG expression by MZL tumor cells correlates with an altered transcription profile and improved overall survival.

TP53 mutations predict for poor survival in de novo diffuse large B-cell lymphoma of germinal center subtype.

Presence of TP53 mutations has been associated with poor prognosis in diffuse large B-cell lymphoma (DLBCL), although this has remained controversial. The TP53 codon 72 polymorphism has shown negative impact on cancer survival, but this has not been analyzed in DLBCL. Furthermore, the MDM2 SNP309 has been associated with earlier age of onset in DLBCL. Here, we investigated the clinical impact of TP53 mutations, MDM2 SNP309 and TP53 codon 72 polymorphisms on survival in DLBCL of germinal center (GC) and non-GC subtypes. Thirteen of the 102 (12.7%) patients displayed TP53 mutations. Overall, TP53 mutations had a significant effect on lymphoma-specific survival (LSS, P=0.009) and progression-free survival (PFS, P=0.028). In particular, inferior survival was observed in TP53-mutated DLBCLs of GC subtype (LSS, P=0.002 and PFS, P=0.006). Neither MDM2 SNP309 nor the TP53 codon 72 polymorphism had an impact on age of onset or survival. Altogether, our data suggests that TP53 mutations are associated with poor outcome in GC-DLBCL patients.