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.

Real-world data on treatment concepts in classical Hodgkin lymphoma in Sweden 2000-2014, focusing on patients aged >60 years.

Treatment for patients > 60 years with classical Hodgkin lymphoma (cHL) is problematic; there is no gold standard, and outcome is poor. Using the Swedish Lymphoma Registry, we analysed all Swedish patients diagnosed with cHL between 2000 and 2014 (N = 2345; median age 42 years; 691 patients were >60 years). The median follow-up time was 6.7 years. Treatment for elderly patients consisted mainly of ABVD or CHOP, and the younger patients were treated with ABVD or BEACOPP (with no survival difference). In multivariable analysis of patients > 60 years, ABVD correlated with better survival than CHOP (p = 0.027), and ABVD became more common over time among patients aged 61-70 years (p = 0.0206). Coinciding with the implementation of FDG-PET/CT, the fraction of advanced-stage disease increased in later calendar periods, also in the older patient group. Survival has improved in cHL patients > 60 years (p = 0.027), for whom ABVD seems superior to CHOP.

No excess long-term mortality in stage I-IIA Hodgkin lymphoma patients treated with ABVD and limited field radiotherapy.

When treating limited stage classical Hodgkin lymphoma (cHL), balancing treatment efficacy and toxicity is important. Toxicities after extended-field radiotherapy are well documented. Investigators have aimed at reducing toxicity without compromising efficacy, mainly by using combined modality treatment (CMT), i.e. chemotherapy and limited-field radiotherapy. In some clinical trials, radiotherapy has been omitted. We evaluated 364 patients with stage I-IIA cHL treated between 1999 and 2005. Patients were treated with two or four cycles of doxorubicin, bleomycin, vinblastine and dacarbazine (ABVD) according to presence of risk factors, followed by 30 Gy limited-field (reduced compared to involved-field) radiotherapy. After a median follow-up of 16 years for survival, freedom from progression at five and ten years was 93% and overall survival at 5 and 10 years was 98% and 96%, respectively. Only two relapses, out of 27, occurred after more than 5 years. There was no excess mortality compared to the general population. Of the analysed subgroups, only patients with progression within five years showed significant excess mortality. The absence of excess mortality questions the concept of omitting radiotherapy after short-term chemotherapy, a strategy that has been associated with an elevated risk of relapse but not yet with a proven reduced long-term excess mortality.

Nodular lymphocyte predominant Hodgkin lymphoma in Sweden between 2000 and 2014: an analysis of the Swedish Lymphoma Registry.

Nodular lymphocyte predominant Hodgkin lymphoma (NLPHL) is an indolent CD20+ lymphoma. Its scarcity has made clinical trials difficult and there is no consensus on first-line treatment. We conducted a population-based study of all patients diagnosed with NLPHL in Sweden between 2000 and 2014 (N = 158; 41 women and 117 men), focusing on clinical features, therapy and overall survival. The median female and male age was 59 and 44 years, respectively (P = 0·002). In early-stage disease, there was little mortality and no survival differences between therapies. In patients with advanced-stage disease, mortality was relatively high in patients who did not receive first-line rituximab but absent in those who did (10-year survival, 55% vs. 100%; P = 0·033); there were no imbalances of prognostic factors between those two groups. In advanced stages, first-line rituximab use increased markedly between 2000-2004 and 2005-2014 (7% vs. 67%; P < 0·00005), as did 10-year survival, 53% vs. 72% (multivariate P = 0·027). Although all patients were diagnosed in the 2000s, this is the longest-followed (and largest) population-based cohort. We report a hitherto unreported 15-year median age difference between sexes, increasing rituximab use and improved survival.

Estrogen receptor ß1 in diffuse large B-cell lymphoma growth and as a prognostic biomarker.

Diffuse large B-cell lymphoma (DLBCL) shows a higher incidence in males versus females. Epidemiological studies have shown that female gender is a favorable prognostic factor, which may be explained by estrogens. Here we show that when grafting human DLBCL cells to immunocompromised mice, tumor growth in males is faster. When treating mice grafted with either germinal center or activated B-cell like DLBCL cells with the selective estrogen receptor ß (ERß) agonist diarylpropionitrile, tumor growth was significantly inhibited. Furthermore, nuclear ERß1 expression analysis in primary DLBCL's by immunohistochemistry revealed expression in 89% of the cases. Nuclear ERß1 expression was in a univariate and multivariate analysis, an independent prognostic factor for adverse progression-free survival in Rituximab-chemotherapy treated DLBCL (p = 0.02 and p = 0.04, respectively). These results suggest that estrogen signaling through ERß1 is an interesting future therapeutic target for treatment of DLBCL, and that ERß1 expression can be used as a prognostic marker.

No survival benefit associated with routine surveillance imaging for Hodgkin lymphoma in first remission: a Danish-Swedish population-based observational study.

The use of routine imaging for patients with classical Hodgkin lymphoma (HL) in complete remission (CR) is controversial. In a population-based study, we examined the post-remission survival of Danish and Swedish HL patients for whom follow-up practices were different. Follow-up in Denmark included routine imaging, usually for a minimum of 2 years, whereas clinical follow-up without routine imaging was standard in Sweden. A total of 317 Danish and 454 Swedish comparable HL patients aged 18-65 years, diagnosed in the period 2007-2012 and having achieved CR following ABVD (doxorubicin, bleomycin, vinblastine, dacarbazine)/BEACOPP (bleomycin, etoposide, doxorubicin, cyclophosphamide, vincristine, procarbazine, prednisone) therapy, were included in the study. The cumulative progression rates in the first 2 years were 4% (95% confidence interval [CI] 1-7) for patients with stage I-II disease vs. 12% (95% CI 6-18) for patients with stage III-IV disease. An imaging-based follow-up practice was not associated with a better post-remission survival in general (P = 0·2) or in stage-specific subgroups (P = 0·5 for I-II and P = 0·4 for III-IV). Age ≥45 years was the only independent adverse prognostic factor for survival. In conclusion, relapse of HL patients with CR is infrequent and systematic use of routine imaging in these patients does not improve post-remission survival. The present study supports clinical follow-up without routine imaging, as encouraged by the recent Lugano classification.

Gene expression profiling indicates that immunohistochemical expression of CD40 is a marker of an inflammatory reaction in the tumor stroma of diffuse large B-cell lymphoma.

Immunohistochemical expression of CD40 is seen in 60-70% of diffuse large B-cell lymphoma (DLBCL) and is associated with a superior prognosis. By using gene expression profiling we aimed to further explore the underlying mechanisms for this effect. Ninety-eight immunohistochemically defined CD40 positive or negative DLBCL tumors, 63 and 35 respectively, were examined using spotted 55K oligonucleotide arrays. CD40 expressing tumors were characterized by up-regulated expression of genes encoding proteins involved in cell-matrix interactions: collagens, integrin αV, proteoglycans and proteolytic enzymes, and antigen presentation. Immunohistochemistry confirmed that CD40 positive tumors co-express the proinflammatory proteoglycan biglycan (p = 0.005), which in turn correlates with the amount of infiltrating macrophages and CD4 and CD8 positive T-cells. We postulate that immunohistochemical expression of CD40 mainly reflects the inflammatory status in tumors. A high intratumoral inflammatory reaction may correlate with an increased autologous tumor response, and thereby a better prognosis.

Inhibition of geranylgeranylation mediates sensitivity to CHOP-induced cell death of DLBCL cell lines.

Prenylation is a post-translational hydrophobic modification of proteins, important for their membrane localization and biological function. The use of inhibitors of prenylation has proven to be a useful tool in the activation of apoptotic pathways in tumor cell lines. Rab geranylgeranyl transferase (Rab GGT) is responsible for the prenylation of the Rab family. Overexpression of Rab GGTbeta has been identified in CHOP refractory diffuse large B cell lymphoma (DLBCL). Using a cell line-based model for CHOP resistant DLBCL, we show that treatment with simvastatin, which inhibits protein farnesylation and geranylgeranylation, sensitizes DLBCL cells to cytotoxic treatment. Treatment with the farnesyl transferase inhibitor FTI-277 or the geranylgeranyl transferase I inhibitor GGTI-298 indicates that the reduction in cell viability was restricted to inhibition of geranylgeranylation. In addition, treatment with BMS1, a combined inhibitor of farnesyl transferase and Rab GGT, resulted in a high cytostatic effect in WSU-NHL cells, demonstrated by reduced cell viability and decreased proliferation. Co-treatment of BMS1 or GGTI-298 with CHOP showed synergistic effects with regard to markers of apoptosis. We propose that inhibition of protein geranylgeranylation together with conventional cytostatic therapy is a potential novel strategy for treating patients with CHOP refractory DLBCL.

CD40 is a potential marker of favorable prognosis in patients with diffuse large B-cell lymphoma treated with immunochemotherapy.

We have previously shown that expression of CD40 has a favorable prognostic impact in diffuse large B-cell lymphoma (DLBCL) after anthracycline-based chemotherapy. Here we examined the prognostic value of immunohistochemically defined CD40 expression in 95 patients with DLBCL treated with both anthracycline-based chemotherapy and rituximab. Using a 10% cut-off level, 77% of the patients had CD40-positive tumors and showed a superior overall survival (p = 0.02 log-rank, hazard ratio 0.35, 95% CI 0.14-0.88, p = 0.03 Cox regression). When adjusted for International Prognostic Index in multivariate analysis, CD40 was not an independent prognostic factor (hazard ratio 0.39, 95% CI 0.15-1.04, p = 0.06 Cox regression). However, even after the introduction of immunochemotherapy, CD40 has a potential prognostic impact in DLBCL. Additional and larger studies are necessary, regarding the immunohistochemical robustness of CD40 and the biological mechanisms that contribute to the superior prognosis in CD40-expressing DLBCL.

Identification of molecular targets associated with transformed diffuse large B cell lymphoma using highly purified tumor cells.

Follicular lymphoma (FL) frequently transforms into the more aggressive diffuse large B cell lymphoma (DLBCL-tr), but no protein biomarkers have been identified for predictive or early diagnosis. Gene expression analyses have identified genes changing on transformation but have failed to be reproducible in different studies, reflecting the heterogeneity within the tumor tissue and between tumor samples. Gene expression analyses on Affymetrix Human Genome U133 Plus 2.0 arrays were performed, using flow cytometry sorted tumor cells derived from FL and transformed DLBCL. To identify molecular targets associated with the transformation, subsequent immunohistochemistry (IHC) analyses of the corresponding proteins were performed. Using highly purified cells, this study identified 163 genes, which were significantly deregulated during the transformation in a majority of cases. Among the upregulated transcripts, 13 genes were selected for validation using IHC, based on the availability of commercial antibodies, and galectin-3 and NEK2 proteins specifically identify DLBCL-tr, when compared with FL. We demonstrate that by purifying tumor cells through cell sorting, thereby reducing the heterogeneity due to infiltrating cells, it was possible to identify distinct differences between tumor entities rather than variations due to cellular composition. Galectin-3 and NEK2 both identified a subgroup of DLBCL-tr, and the function of these protein markers also suggests a biological role in the transformation process.

Genes associated with the tumour microenvironment are differentially expressed in cured versus primary chemotherapy-refractory diffuse large B-cell lymphoma.

In order to identify genes associated with primary chemotherapy-resistance, gene expression profiles (GEP) in tumour tissue from 37 patients with de novo diffuse large B-cell lymphoma (DLBCL), stage II-IV, either in continuous complete remission (n = 24) or with progressive disease during primary treatment (n = 13), were examined using spotted 55K oligonucleotide arrays. Immunohistochemistry was used for confirmation at the protein level. The top 86 genes that best discriminated between the two cohorts were chosen for further analysis. Only seven of 86 genes were overexpressed in the refractory cohort, e.g. RABGGTB and POLE, both potential targets for drug intervention. Seventy-nine of 86 genes were overexpressed in the cured cohort and mainly coded for proteins expressed in the tumour microenvironment, many of them involved in proteolytic activity and remodelling of extra cellular matrix. Furthermore, major histocompatibility complex class I molecules, CD3D and ICAM1 were overexpressed, indicating an enhanced immunological reaction. Immunohistochemistry confirmed the GEP results. The frequency of tumour infiltrating lymphocytes, macrophages, and reactive cells expressing ICAM-1, lysozyme, cathepsin D, urokinase plasminogen activator receptor, signal transducer and activator of transcription 1, and galectin-3 was higher in the cured cohort. These findings indicate that a reactive microenvironment has an impact on the outcome of chemotherapy in DLBCL.

A subset of CD5- diffuse large B-cell lymphomas expresses nuclear cyclin D1 with aberrations at the CCND1 locus.

In 231 diffuse large B-cell lymphomas, the expression of cyclin D1 and CD5 was evaluated. All cases were CD5-. Ten (4.3%) were positive for cyclin D1 and were subjected to fluorescence in situ hybridization at the CCND1 locus. One case showed the t(11;14). In another case, the telomeric probe signal for cyclin D1 was lost in most tumor cells, and in a small proportion of the cells, there were fluorescence signals indicative of the t(11;14). Two other cases displayed additional cyclin D1 signals in the absence of the t(11;14). All cases but 1 were positive for bcl-6 or MUM1, disfavoring the possibility of misdiagnosed blastoid variants of CD5- mantle cell lymphomas. Thus, contrary to the current view, there seems to exist a certain number of cyclin D1+ and CD5- diffuse large B-cell lymphomas, some of which have structural aberrations at the CCND1 locus, including the t(11;14).

Protein expression and cellular localization in two prognostic subgroups of diffuse large B-cell lymphoma: higher expression of ZAP70 and PKC-beta II in the non-germinal center group and poor survival in patients deficient in nuclear PTEN.

Patients diagnosed with diffuse large B-cell lymphoma (DLBCL) show varying responses to conventional therapy, and this might be contributed to the differentiation stage of the tumor B-cells. The aim of the current study was to evaluate a panel of kinases (ZAP70, PKC-beta I and II and phosphorylated PKB/Akt) and phosphatases (PTEN, SHP1 and SHP2) known to be frequently deregulated in lymphoid malignancies. De novo DLBCL cases were divided into two subgroups, the germinal center (GC) group (14/28) and the non-germinal center (non-GC) or activated B-cell (ABC) group (14/28). ZAP70 and PKC-beta II were expressed in a significantly higher percentage of tumor cells in the clinically more aggressive non-GC group compared with the prognostically favourable GC group. Also, the subcellular localization of PKC-beta I and II differed in DLBCL cells, with the PKC-beta I isoform being expressed in both the cytoplasm and nucleus, while PKC-beta II was found exclusively in the cytoplasm. Loss of nuclear PTEN correlated with poor survival in cases from both subgroups. In addition, five cell lines of DLBCL origin were analyzed for protein expression and for mRNA levels of PTEN and SHP1. For the first time, we show that ZAP70 is expressed in a higher percentage of tumor cells in the aggressive non-GC subgroup of DLBCL and that PKC-beta I and II are differently distributed in the two prognostic subgroups of de novo DLBCL.

CD40 expression identifies a prognostically favourable subgroup of diffuse large B-cell lymphoma.

In order to confirm our earlier findings of the prognostic effects of CD23 and CD40 expression in diffuse large B-cell lymphoma (DLBCL), possibly due to association with the germinal center (GC) phenotype and/or an increased autologous tumour response, tumour specimens from 125 patients with de novo DLBCL were investigated for immunohistochemical expression of CD23, CD40, BCL6, CD10, MUM1, CD4 and CD8. CD40 was positive in 64% and was associated with improved overall survival (p = 0.03). A GC phenotype was present in 47%, and was also associated with a better overall survival (p = 0.006) but did not correlate with CD40-expression. There was no correlation between amount of tumour infiltrating T-cells and CD40-positivity. CD23 was positive in 10% and expression did not correlate with prognosis. In conclusion, the prognostic effect of CD40 expression was confirmed, but did not correlate with GC-phenotype or T-cell infiltration.

Tissue microarray is inappropriate for analysis of BCL6 expression in diffuse large B-cell lymphoma.

OBJECTIVE: In this study, our aim was to investigate how different immunohistochemical techniques may influence the result of BCL6 positivity and categorization in germinal center (GC) and non-GC derived diffuse large B-cell lymphoma (DLBCL), as it has been proposed that classification of DLBCL according to cell-of-origin by immunohistochemistry may be performed as a routine procedure in the diagnostic work-up. However, a number of technical issues need to be solved before introducing this as a standard technique. METHODS: Tumor specimens from 122 patients with de novo stage II-IV disease, adequately treated with anthracycline-containing chemotherapy regimens were collected. Immunohistochemical expression of BCL6, CD10, and MUM-1/IRF4 was examined using a tissue microarray (TMA) technique. BCL6 and CD10 were also evaluated on whole tissue sections. RESULTS: Due to profound tissue heterogeneity, BCL6 showed a wide range of positivity, with a high number of false negative results by TMA (25% positive), compared to 53% on whole tissue sections (WTS). CD10 was more homogeneously expressed, and TMA results corresponded better to WTS. Consequently, the results from categorization into GC and non-GC DLBCL differed considerably by use of the two methods, and resulted in very different outcome in terms of overall survival. CONCLUSION: Immunohistochemical GC-status determined on TMA is not reliable enough to be used for individual treatment decisions in DLBCL, mostly due to difficulties in interpreting BCL6 status.

Evaluation of immunophenotype in diffuse large B-cell lymphoma and its impact on prognosis.

Diffuse large B-cell lymphoma (DLBCL) has been shown to be comprised of at least two prognostic entities, depending on its resemblance to normal germinal center or activated B cells, using global gene expression profiling. Also, the expression patterns of bcl-6, CD10 and IRF-4 (also known as MUM1) have been suggested as alternative means of identifying the germinal- and nongerminal center (activated B-cell like) groups. In the present study, we evaluated by immunohistochemistry the expression patterns of CD10, bcl-6, IRF-4 and bcl-2 in a large material of 161 DLBCL patients. Using two different approaches, patients with germinal center phenotype displayed a significantly better survival than the nongerminal center group. Positive staining for bcl-6 or CD10 predicted for superior survival, while expression of IRF-4 alone showed no association with prognosis. Furthermore, expression of bcl-2 was associated with worse event-free survival and overall survival. In a multivariate analysis, a high international prognostic index score (3-5), non-GC phenotype and bcl-2 were independent adverse prognostic factors. Here we confirm the prognostic importance of determining the germinal- or nongerminal center phenotype in patients with DLBCL.

Immunohistochemical expression of CD23 and CD40 may identify prognostically favorable subgroups of diffuse large B-cell lymphoma: a Nordic Lymphoma Group Study.

PURPOSE: In search for subgroups of diffuse large B-cell lymphoma (DLBCL) with different histogenetic origin and prognosis, as has been described by gene expression profiling, we examined tumor specimens from 125 patients with DLBCL, uniformly treated by either cyclophosphamideAdriamycin-vincristine-prednisone or methotrexate, doxorubicin, cyclophosphamide, vincristine, prednisone, and bleomycin in a multicenter trial set by the Nordic Lymphoma Group 1989-1994. EXPERIMENTAL DESIGN: Bcl-6, CD10, and CD40 were chosen as markers for a germinal center phenotype, CD23 as a marker of pre/early germinal center origin, and CD138 as a marker for postgerminal center origin. In addition, expression of the apoptotic regulators bcl-2 and bax was analyzed. Immunohistochemical analysis was performed using the EnVision method. RESULTS: CD10 was positive in 51%, bcl-6 in 97%, and CD138 only in 2% of the cases. No prognostic conclusions could be drawn from analysis of these factors. CD40 was positive in 76% of the cases. This group was associated with superior time to treatment failure (P = 0.027) and overall survival (OS; P = 0.0068). By Cox regression analysis, positivity for CD40 was shown to be a prognostic factor for OS, independent of International Prognostic Index. CD23 was positive in 16% of the cases (all CD5 negative and all CD40 positive). This group showed a strong tendency for better OS (P = 0.033). CD40 expression correlated with bax but not with bcl-2 expression. CONCLUSIONS: CD23 and CD40 expression seems to be prognostically favorable in DLBCL. This may be secondary to a germinal center origin or attributable to increased apoptosis via induction of bax and/or enhanced T-cell interaction, resulting in improved autologous tumor response. Confirmatory studies are necessary.