Search

PTEN loss has been associated with poorer prognosis in many solid tumors. However, such investigation in lymphomas is limited. In this study, PTEN cytoplasmic and nuclear expression, PTEN gene deletion, and PTEN mutations were evaluated in two independent cohorts of diffuse large B-cell lymphoma (DLBCL). Cytoplasmic PTEN expression was found in approximately 67% of total 747 DLBCL cases, more frequently in the activated B-cell-like subtype. Nuclear PTEN expression was less frequent and at lower levels, which significantly correlated with higher PTEN mRNA expression. Remarkably, loss of PTEN protein expression was associated with poorer survival only in DLBCL with AKT hyperactivation. In contrast, high PTEN expression was associated with Myc expression and poorer survival in cases without abnormal AKT activation. Genetic and epigenetic mechanisms for loss of PTEN expression were investigated. PTEN deletions (mostly heterozygous) were detected in 11.3% of DLBCL, and showed opposite prognostic effects in patients with AKT hyperactivation and in MYC rearranged DLBCL patients. PTEN mutations, detected in 10.6% of patients, were associated with upregulation of genes involved in central nervous system function, metabolism, and AKT/mTOR signaling regulation. Loss of PTEN cytoplasmic expression was also associated with TP53 mutations, higher PTEN-targeting microRNA expression, and lower PD-L1 expression. Remarkably, low PTEN mRNA expression was associated with down-regulation of a group of genes involved in immune responses and B-cell development/differentiation, and poorer survival in DLBCL independent of AKT activation. Collectively, multi-levels of PTEN abnormalities and dysregulation may play important roles in PTEN expression and loss, and that loss of PTEN tumor-suppressor function contributes to the poor survival of DLBCL patients with AKT hyperactivation., (Copyright © 2017 The Authors. Published by Elsevier Inc. All rights reserved.)

Objective: Cancer therapy-induced inflammation of oral and gastrointestinal mucosae affects patients nonuniformly. Preventive strategies are limited; no biomarker exists for pretreatment identification of patients likely to be severely affected. Animal models are preferred for studying molecular responses in mucosae during chemotherapy, but translation into clinical practice is difficult. We performed a systematic review to retrieve articles that described molecular changes in human mucosae during cancer therapy., Study Design: We searched MEDLINE and Ovid Embase searches for studies reported in the English language literature from January 1990 to November 2016 and studies referenced in selected articles, which analyzed mucosae from patients at risk of developing mucositis during cancer therapy. Two authors extracted data according to predefined data fields, including study quality indicators., Results: We identified 17 human studies on chemotherapy (n = 9) and radiotherapy (n = 8), but no studies on targeted therapy. Studies were heterogeneous with regard to patient cohorts, analysis methods, cancer treatments, biopsy timings, and correlations to clinical mucositis. Consequently, a meta-analysis was not feasible., Conclusions: Few human studies described the molecular responses of the normal mucosa to cancer therapy. Studies were heterogeneous and had sparse correlations to clinical mucositis. We proposed a model for acquiring data on treatment- and disease-specific phenotypes and transcriptomes for predictive or preventive initiatives., (Copyright © 2017 Elsevier Inc. All rights reserved.)

AKT signaling is important for proliferation and survival of tumor cells. The clinical significance of AKT activation in diffuse large B-cell lymphoma (DLBCL) is not well analyzed. Here, we assessed expression of phosphorylated AKT (p-AKT) in 522 DLBCL patients. We found that high levels of p-AKT nuclear expression, observed in 24.3% of the study cohort, were associated with significantly worse progression-free survival and Myc and Bcl-2 overexpression. However, multivariate analysis indicated that AKT hyperactivation was not an independent factor. miRNA profiling analysis demonstrated that 63 miRNAs directly or indirectly related to the phosphatidylinositol 3-kinase/AKT/mechanistic target of rapamycin pathway were differentially expressed between DLBCLs with high and low p-AKT nuclear expression. We further targeted AKT signaling using a highly selective AKT inhibitor MK-2206 in 26 representative DLBCL cell lines and delineated signaling alterations using a reverse-phase protein array. MK-2206 treatment inhibited lymphoma cell viability, and MK-2206 sensitivity correlated with AKT activation status in DLBCL cells. On MK-2206 treatment, p-AKT levels and downstream targets of AKT signaling were significantly decreased, likely because of the decreased feedback repression; Rictor and phosphatidylinositol 3-kinase expression and other compensatory pathways were also induced. This study demonstrates the clinical and therapeutic implications of AKT hyperactivation in DLBCL and suggests that AKT inhibitors need to be combined with other targeted agents for DLBCL to achieve optimal clinical efficacy., (Copyright © 2017 American Society for Investigative Pathology. Published by Elsevier Inc. All rights reserved.)

CD37 (tetraspanin TSPAN26) is a B-cell surface antigen widely expressed on mature B cells. CD37 is involved in immune regulation and tumor suppression but its function has not been fully elucidated. We assessed CD37 expression in de novo diffuse large B-cell lymphoma (DLBCL), and investigated its clinical and biologic significance in 773 patients treated with rituximab plus cyclophosphamide, doxorubicin, vincristine, and prednisone (R-CHOP) and 231 patients treated with CHOP. We found that CD37 loss (CD37 - ) in ∼60% of DLBCL patients showed significantly decreased survival after R-CHOP treatment, independent of the International Prognostic Index (IPI), germinal center B-cell-like (GCB)/activated B-cell-like (ABC) cell of origin, nodal/extranodal primary origin, and the prognostic factors associated with CD37 - , including TP53 mutation, NF-κB high , Myc high , phosphorylated STAT3 high , survivin high , p63 - , and BCL6 translocation. CD37 positivity predicted superior survival, abolishing the prognostic impact of high IPI and above biomarkers in GCB-DLBCL but not in ABC-DLBCL. Combining risk scores for CD37 - status and ABC cell of origin with the IPI, defined as molecularly adjusted IPI for R-CHOP (M-IPI-R), or IPI plus immunohistochemistry (IHC; IPI+IHC) for CD37, Myc, and Bcl-2, significantly improved risk prediction over IPI alone. Gene expression profiling suggested that decreased CD20 and increased PD-1 levels in CD37 - DLBCL, ICOSLG upregulation in CD37 + GCB-DLBCL, and CD37 functions during R-CHOP treatment underlie the pivotal role of CD37 status in clinical outcomes. In conclusion, CD37 is a critical determinant of R-CHOP outcome in DLBCL especially in GCB-DLBCL, representing its importance for optimal rituximab action and sustained immune responses. The combined molecular and clinical prognostic indices, M-IPI-R and IPI+IHC, have remarkable predictive values in R-CHOP-treated DLBCL., (© 2016 by The American Society of Hematology.)

We studied the global microRNA (miRNA) expression in diffuse large B-cell lymphoma (DLBCL; n = 79), Burkitt lymphoma (BL; n = 36), primary mediastinal B-cell lymphoma (PMBL; n = 12), B-cell lines (n = 11), and normal subsets of naïve B cells, centroblasts (CBs), and peripheral blood B cells along with their corresponding gene expression profiles (GEPs). The normal B-cell subsets have well-defined miRNA signatures. The CB miRNA signature was significantly associated with germinal center B-cell (GCB)-DLBCL compared with activated B-cell (ABC)-DLBCL (P = .002). We identified a 27-miRNA signature that included v-myc avian myelomatosis viral oncogene homolog (MYC) targets and enabled the differentiation of BL from DLBCL, a distinction comparable with the "gold standard" GEP-defined diagnosis. Distinct miRNA signatures were identified for DLBCL subgroups, including GCB-DLBCL, activated B-cell (ABC)-DLBCL, and PMBL. Interestingly, most of the unclassifiable-DLBCL by GEP showed a strong similarity to the ABC-DLBCL by miRNA expression profiling. Consistent results for BL and DLBCL subgroup classification were observed in formalin-fixed, paraffin-embedded tissue, making such tests practical for clinical use. We also identified predictive miRNA biomarker signatures in DLBCL, including high expression of miR-155, which is significantly associated with rituximab plus cyclophosphamide, doxorubicin, vincristine, and prednisone (R-CHOP) treatment failure. This finding was further supported by the observation that high expression of miR-155 sensitizes cells to v-akt murine thymoma viral oncogene homolog-1 inhibitors in vitro, suggesting a novel treatment option for resistant DLBCL.

MDM2 is a key negative regulator of the tumor suppressor p53, however, the prognostic significance of MDM2 overexpression in diffuse large B-cell lymphoma (DLBCL) has not been defined convincingly. In a p53 genetically-defined large cohort of de novo DLBCL patients treated with rituximab, cyclophosphamide, hydroxydaunorubicin, vincristine, and prednisone (R-CHOP) chemotherapy, we assessed MDM2 and p53 expression by immunohistochemistry (n = 478), MDM2 gene amplification by fluorescence in situ hybridization (n = 364), and a single nucleotide polymorphism in the MDM2 promoter, SNP309, by SNP genotyping assay (n = 108). Our results show that MDM2 overexpression, unlike p53 overexpression, is not a significant prognostic factor in overall DLBCL. Both MDM2 and p53 overexpression do not predict for an adverse clinical outcome in patients with wild-type p53 but predicts for significantly poorer survival in patients with mutated p53. Variable p53 activities may ultimately determine the survival differences, as suggested by the gene expression profiling analysis. MDM2 amplification was observed in 3 of 364 (0.8%) patients with high MDM2 expression. The presence of SNP309 did not correlate with MDM2 expression and survival. This study indicates that evaluation of MDM2 and p53 expression correlating with TP53 genetic status is essential to assess their prognostic significance and is important for designing therapeutic strategies that target the MDM2-p53 interaction.

Anaplastic large-cell lymphomas (ALCLs) encompass at least 2 systemic diseases distinguished by the presence or absence of anaplastic lymphoma kinase (ALK) expression. We performed genome-wide microRNA (miRNA) profiling on 33 ALK-positive (ALK[+]) ALCLs, 25 ALK-negative (ALK[-]) ALCLs, 9 angioimmunoblastic T-cell lymphomas, 11 peripheral T-cell lymphomas not otherwise specified (PTCLNOS), and normal T cells, and demonstrated that ALCLs express many of the miRNAs that are highly expressed in normal T cells with the prominent exception of miR-146a. Unsupervised hierarchical clustering demonstrated distinct clustering of ALCL, PTCL-NOS, and the AITL subtype of PTCL. Cases of ALK(+) ALCL and ALK(-) ALCL were interspersed in unsupervised analysis, suggesting a close relationship at the molecular level. We identified an miRNA signature of 7 miRNAs (5 upregulated: miR-512-3p, miR-886-5p, miR-886-3p, miR-708, miR-135b; 2 downregulated: miR-146a, miR-155) significantly associated with ALK(+) ALCL cases. In addition, we derived an 11-miRNA signature (4 upregulated: miR-210, miR-197, miR-191, miR-512-3p; 7 downregulated: miR-451, miR-146a, miR-22, miR-455-3p, miR-455-5p, miR-143, miR-494) that differentiates ALK(-) ALCL from other PTCLs. Our in vitro studies identified a set of 32 miRNAs associated with ALK expression. Of these, the miR-17∼92 cluster and its paralogues were also highly expressed in ALK(+) ALCL and may represent important downstream effectors of the ALK oncogenic pathway.

We identified multiple single nucleotide variants (SNVs) in the TP53 3' untranslated region (3'UTR) in tumor specimens from 244 patients with diffuse large B-cell lymphoma (DLBCL). Patients carrying a wild-type TP53 coding sequence (CDS) and 1 or more 3'UTR SNVs had a better 5-year survival rate than patients carrying a wild-type CDS and the reference 3'UTR, yet there is no statistically significance difference in overall survival (OS). In contrast, 3'UTR variation predicted poorer OS for patients with a mutant TP53 CDS. We then sequenced TP53 3'UTR in 247 additional DLBCL patients as a validation set. Altogether, we identified 187 novel SNVs; 36 occurred at least twice. Most of the newly identified 3'UTR SNVs were located at sites that are complementary to seed sequences of microRNAs (miRNAs) that are predicted or experimentally known to target TP53. Three SNVs disrupt the seed match between miR-125b and the TP53 3'UTR, thereby impeding suppression of p53 by this miRNA. In addition, a germline SNV (rs78378222) located in the TP53 polyadenylation signal resulted in downregulation of both p53 messenger RNA and protein levels and reduction of cellular apoptosis. This study is the first to demonstrate the prognostic value of the TP53 3'UTR in cancer.

Diffuse large B-cell lymphoma (DLBCL) is stratified into prognostically favorable germinal center B-cell (GCB)-like and unfavorable activated B-cell (ABC)-like subtypes based on gene expression signatures. In this study, we analyzed 893 de novo DLBCL patients treated with R-CHOP (rituximab, cyclophosphamide, doxorubicin, vincristine, and prednisone). We show that MYC/BCL2 protein coexpression occurred significantly more commonly in the ABC subtype. Patients with the ABC or GCB subtype of DLBCL had similar prognoses with MYC/BCL2 coexpression and without MYC/BCL2 coexpression. Consistent with the notion that the prognostic difference between the 2 subtypes is attributable to MYC/BCL2 coexpression, there is no difference in gene expression signatures between the 2 subtypes in the absence of MYC/BCL2 coexpression. DLBCL with MYC/BCL2 coexpression demonstrated a signature of marked downregulation of genes encoding extracellular matrix proteins, those involving matrix deposition/remodeling and cell adhesion, and upregulation of proliferation-associated genes. We conclude that MYC/BCL2 coexpression in DLBCL is associated with an aggressive clinical course, is more common in the ABC subtype, and contributes to the overall inferior prognosis of patients with ABC-DLBCL. In conclusion, the data suggest that MYC/BCL2 coexpression, rather than cell-of-origin classification, is a better predictor of prognosis in patients with DLBCL treated with R-CHOP.

CD30, originally identified as a cell-surface marker of Reed-Sternberg and Hodgkin cells of classical Hodgkin lymphoma, is also expressed by several types of non-Hodgkin lymphoma, including a subset of diffuse large B-cell lymphoma (DLBCL). However, the prognostic and biological importance of CD30 expression in DLBCL is unknown. Here we report that CD30 expression is a favorable prognostic factor in a cohort of 903 de novo DLBCL patients. CD30 was expressed in ∼14% of DLBCL patients. Patients with CD30(+) DLBCL had superior 5-year overall survival (CD30(+), 79% vs CD30(-), 59%; P = .001) and progression-free survival (P = .003). The favorable outcome of CD30 expression was maintained in both the germinal center B-cell and activated B-cell subtypes. Gene expression profiling revealed the upregulation of genes encoding negative regulators of nuclear factor κB activation and lymphocyte survival, and downregulation of genes encoding B-cell receptor signaling and proliferation, as well as prominent cytokine and stromal signatures in CD30(+) DLBCL patients, suggesting a distinct molecular basis for its favorable outcome. Given the superior prognostic value, unique gene expression signature, and significant value of CD30 as a therapeutic target for brentuximab vedotin in ongoing successful clinical trials, it seems appropriate to consider CD30(+) DLBCL as a distinct subgroup of DLBCL.

TP53 mutation is an independent marker of poor prognosis in patients with diffuse large B-cell lymphoma (DLBCL) treated with cyclophosphamide, hydroxydaunorubicin, vincristine, and prednisone (CHOP) therapy. However, its prognostic value in the rituximab immunochemotherapy era remains undefined. In the present study of a large cohort of DLBCL patients treated with rituximab plus CHOP (R-CHOP), we show that those with TP53 mutations had worse overall and progression-free survival compared with those without. Unlike earlier studies of patients treated with CHOP, TP53 mutation has predictive value for R-CHOP-treated patients with either the germinal center B-cell or activated B-cell DLBCL subtypes. Furthermore, we identified the loop-sheet-helix and L3 motifs in the DNA-binding domain to be the most critical structures for maintaining p53 function. In contrast, TP53 deletion and loss of heterozygosity did not confer worse survival. If gene mutation data are not available, immunohistochemical analysis showing > 50% cells expressing p53 protein is a useful surrogate and was able to stratify patients with significantly different prognoses. We conclude that assessment of TP53 mutation status is important for stratifying R-CHOP-treated patients into distinct prognostic subsets and has significant value in the design of future therapeutic strategies.

Peripheral T-cell lymphoma (PTCL) is often challenging to diagnose and classify. Gene expression profiling was performed on 144 cases of PTCL and natural killer cell lymphoma and robust molecular classifiers were constructed for angioimmunoblastic T-cell lymphoma (AITL), anaplastic lymphoma kinase-positive (ALK(+)) anaplastic large-cell lymphoma (ALCL), and adult T-cell leukemia/lymphoma. PTCL-unclassifiable was molecularly heterogeneous, but we were able to identify a molecular subgroup with features of cytotoxic T lymphocytes and a poor survival compared with the remaining PTCL-not otherwise specified cases. Many of the pathologic features and substantial components of the molecular signature of AITL are contributed by the follicular dendritic cells, B-cell, and other stromal components. The expression of Th17-associated molecules in ALK(+) ALCL was noted and may represent aberrant activation of Th17-cell differentiation by abnormal cytokine secretion. Adult T-cell leukemia/lymphoma has a homogeneous molecular signature demonstrating high expression of human T-lymphotropic virus type 1-induced genes. These classifiers reflect the biology of the tumor cells as well as their microenvironment. We also constructed a molecular prognosticator for AITL that appears to be largely related to the microenvironmental signature, and the high expression of 2 immunosuppressive signatures are associated with poor outcome. Oncogenic pathways and tumor-host interactions also were identified, and these findings may lead to better therapies and outcome in the future.