Recent prognostic factors in diffuse large B-cell lymphoma indicate NF-kappaB pathway as a target for new therapeutic strategies

Fc receptor-like 1 (FCRL1) is a novel biomarker for prognosis and a possible therapeutic target in diffuse large B-cell lymphoma

BACKGROUND

Diffuse large B-cell lymphoma (DLBCL) is the most common subtype of non-Hodgkin's lymphoma, which can involve various types of mature B-cells. Considering that the incidence of DLBCL has increased, additional research is required to identify novel and effective prognostic and therapeutic molecules. Fc receptor-like 1 (FCRL1) acts as an activation co-receptor of human B-cells. Aberrant expression of this molecule has been reported in a number of B-cell-related disorders. Moreover, the clinical significance and prognosis value of FCRL1 in DLBCL are not completely identified.

METHODS

In this study, the expression levels of FCRL1 were determined in thirty patients with DLBCL and 15 healthy controls (HCs). In addition, the correlation between FCRL1 expressions with clinicopathological variables of DLBCL patients were examined. Then, the potential roles of FCRL1 in proliferation, apoptosis, and cell cycle distribution of B-cells from DLBCL patients were determined using flow cytometry analysis, after knockdown of this marker using retroviral short hairpin RNA interference. Quantitative real time-PCR, western blotting, and enzyme-linked immunosorbent assay were also used to identify the possible effects of FCRL1 knockdown on the expression levels of BCL-2, BID, BAX, intracellular signaling pathway PI3K/p-Akt, and p65 nuclear factor-kappa B (NF-κB) in the B-cells of DLBCL.

RESULTS

Statistical analysis revealed higher levels of FCRL1 expression in the B-cells of DLBCL patients compared to HCs at both protein and mRNA levels. A positive correlation was observed between the FCRL1 expression and some clinicopathological parameters of DLBCL patients. In addition, FCRL1 knockdown significantly decreased cell proliferation and stimulated apoptosis as well as G1 cell cycle arrest in the B-cells of DLBCL patients. The levels of p65 NF-κB and PI3K/p-Akt expressions were markedly reduced after knockdown of FCRL1 expression.

CONCLUSIONS

These results suggested that FCRL1 could be a potential novel biomarker for prognosis and/or a possible effective therapeutic target for treatment of patients with DLBCL.

Scaffold-mediated switching of lymphoma metabolism in culture

Background

Diffuse large B cell lymphoma (DLBCL) is an aggressive subtype of non-Hodgkin lymphoma (NHL) and accounts for about a third of all NHL cases. A significant proportion (~40%) of treated DLBCL patients develop refractory or relapsed disease due to drug resistance which can be attributed to metabolomic and genetic variations amongst diverse DLBCL subtypes. An assay platform that reproduces metabolic patterns of DLBCL in vivo could serve as a useful model for DLBCL.

Methods

This report investigated metabolic functions in 2D and 3D cell cultures using parental and drug-resistant DLBCL cell lines as compared to patient biopsy tissue.

Results

A 3D culture model controlled the proliferation of parental and drug-resistant DLBCL cell lines, SUDHL-10, SUDHL-10 RR (rituximab resistant), and SUDHL-10 OR (obinutuzumab resistant), as well as retained differential sensitivity to CHOP. The results from metabolic profiling and isotope tracer studies with d-glucose-¹³C₆ indicated metabolic switching in 3D culture when compared with a 2D environment. Analysis of DLBCL patient tumor tissue revealed that the metabolic changes in 3D grown cells were shifted towards that of clinical specimens.

Conclusion

3D culture restrained DLBCL cell line growth and modulated metabolic pathways that trend towards the biological characteristics of patient tumors. Counter-intuitively, this research thereby contends that 3D matrices can be a tool to control tumor function towards a slower growing and metabolically dormant state that better reflects in vivo tumor physiology.

Supplementary Information

The online version contains supplementary material available at 10.1186/s40170-022-00291-y.

Transcriptomics-Based Investigation of Molecular Mechanisms Underlying Apoptosis Induced by ZnO Nanoparticles in Human Diffuse Large B-Cell Lymphoma

Introduction

Zinc oxide nanoparticles (ZnO NPs) show anti-cancer activity. Diffuse Large B-cell Lymphoma (DLBCL) is a type of B-cell malignancies with unsatisfying treatment outcomes. This study was set to assess the potential of ZnO NPs to selectively induce apoptosis in human DLBCL cells (OCI-LY3), and to describe possible molecular mechanisms of action.

Methods

The impact of ZnO NPs on DLBCL cells and normal peripheral blood mononuclear cells (PBMCs) was studied using cytotoxicity assay and flow-cytometry. Transcriptomics analysis was conducted to identify ZnO NPs-dependent changes in the transcriptomic profiles of DLBCL cells.

Results

ZnO NPs selectively induced apoptosis in DLBCL cells, and caused changes in their transcriptomes. Deferential gene expression (DGE) with fold change (FC) ≥3 and p ≤ 0.008 with corrected p ≤ 0.05 was identified for 528 genes; 125 genes were over-expressed and 403 genes were under-expressed in ZnO NPs-treated DLBCL cells. The over-expressed genes involved in biological processes and pathways like stress response to metal ion, cellular response to zinc ion, metallothioneins bind metals, oxidative stress, and negative regulation of growth. In contrast, the under-expressed genes were implicated in DNA packaging complex, signaling by NOTCH, negative regulation of gene expression by epigenetic, signaling by WNT, M phase of cell cycle, and telomere maintenance. Setting the FC to ≥1.5 with p ≤ 0.05 and corrected p ≤ 0.1 showed ZnO NPs to induce over-expression of anti-oxidant genes and under-expression of oncogenes; target B-cell receptor (BCR) signaling pathway and NF-κB pathway; and promote apoptosis by intrinsic and extrinsic pathways.

Discussion

Overall, ZnO NPs selectively induced apoptosis in DLBCL cells, and possible molecular mechanisms of action were described.

Fc Receptor-Like 1 as a Promising Target for Immunotherapeutic Interventions of B-Cell-Related Disorders

BACKGROUND

Human B-cell responses are regulated through synergy between a collection of activation and inhibitory receptors. Fc receptor-like (FCRL) molecules have recently been identified as co-receptors that are preferentially expressed in human B-cells, which may also play an important role in the regulation of human B-cell responses. FCRL1 is a member of the FCRL family molecules with 2 immunoreceptor tyrosine-based activation motifs (ITAMs) in its cytoplasmic tail. This study aimed to investigate the regulatory roles of FCRL1 in human B-cell responses.

MATERIALS AND METHODS

The regulatory potential of FCRL1 in human B-cell through knockdown of FCRL1 expression in the Ramos and Daudi Burkitt lymphoma (BL) cell lines by using the retroviral-based short hairpin ribonucleic acid (shRNA) delivery method. The functional consequences of FCRL1 knockdown were assessed by measuring the proliferation, apoptosis, and the expression levels of Bcl-2, Bid, and Bax genes as well as phosphoinositide-3 kinase/-serine-threonine kinase AKT (PI3K/p-AKT) pathway in the BL cells, using the quantitative real-time polymerase chain reaction (PCR) and flow cytometry analysis. The NF-κB activity was also measured by the enzyme-linked immunosorbent assay (ELISA).

RESULTS

FCRL1 knockdown significantly decreased cell proliferation and increased apoptotic cell death in the BL cells. There was a significant reduction in the extent of the Bcl-2 gene expression in the treated BL cells compared with control cells. On the contrary, FCRL1 knockdown increased the expression levels of Bid and Bax genes in the treated BL cells when compared with control cells. In addition, the extent of the PI3K/p-AKT expression and phosphorylated-p65 NF-κB activity was significantly decreased in the treated BL cells compared with control cells.

CONCLUSIONS

These results suggest that FCRL1 can play a key role in the activation of human B-cell responses and has the potential to serve as a target for immunotherapy of FCRL1 positive B-cell-related disorders.

Prognostic value of expression of nuclear factor kappa-B/p65 in non-GCB DLBCL patients

Purpose

We estimated the expression of nuclear factor kappa B/p65 in non-germinal center B-cell-like subtype diffuse large B-cell lymphoma, to investigate its relationship to clinicopathological features, and to further evaluate its prognostic value and clarify its impact on survival.

Results

Among the 49 patients enrolled in this study, 14 (28.6%) had positive p65 expression. The negative p65 group had significantly better survival compared to the positive p65 group in terms of both the 3-year estimated OS (91.2% vs. 39.3%, p = 0.003) and PFS (75.6% vs. 26.5%, p = 0.002). In patients with 4 or more risk factors, p65 was an independent prognostic factor of OS (HR 5.99, 95%CI=1.39-25.75, p=0.016) and PFS (HR 4.01, 95%CI=1.15-14.00, p=0.029).

Materials and Methods

The expression of the NF-κB/p65 protein was deteremined by immunohistochemistry in 49 non-GCB DLBCL. Survival was assessed by the Kaplan–Meier method and Cox multivariate analysis. The median patient follow-up period was 24 months.

Conclusions

The expression of NF-κB/p65 has prognostic value in high risk non-GCB DLBCL, and it is a suitable target for the development of new therapies.

WITHDRAWN: ALDH1A1 induces resistance to CHOP in diffuse large B-cell lymphoma through activation of the JAK2/STAT3 pathway

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ALDH1A1 induces resistance to CHOP in diffuse large B-cell lymphoma through activation of the JAK2/STAT3 pathway

Increasing evidence has shown that aldehyde dehydrogenase 1A1 (ALDH1A1), a detoxifying enzyme, is responsible for chemoresistance in a variety of tumors. Although the majority of patients with diffuse large B-cell lymphoma (DLBCL) can be cured with cyclophosphamide, doxorubicin, vincristine, and prednisone (CHOP), chemoresistance is a common cause of treatment failure. This study aims to investigate the significance of ALDH1A1 expression and the mechanism by which ALDH1A1 is involved in the chemoresistance of DLBCL cells. ALDH1A1 expression was assessed in 88 DLBCL tissues by immunohistochemistry. The association between ALDH1A1 expression and outcome was evaluated. We also investigated the effect of ALDH1A1 on CHOP resistance in DLBCL cells using functional analysis. ALDH1A1 expression levels were upregulated in patients with stable or progressive disease after CHOP and its expression positively correlated with expression of STAT3 and p-STAT3. In keeping with these observations, ALDH1A1 expression was significantly associated with short survival of DLBCL patients who received CHOP chemotherapy. In functional assays in Pfeiffer cells, overexpression of ALDH1A1 conferred resistance to CHOP, while silencing of ALDH1A1 using short hairpin RNA had the opposite effect. Furthermore, we also observed that ALDH1A1 could regulate the JAK2/STAT3 pathway, while inhibition of the JAK2/STAT3 pathway by WP1066 negated the effect of ALDH1A1 overexpression. These observations reveal that ALDH1A1 induces resistance to CHOP through activation of the JAK2/STAT3 pathway in DLBCL, and its targeting provides a potential strategic approach for reversing CHOP resistance.

Clinical significance of nuclear factor κB and chemokine receptor CXCR4 expression in patients with diffuse large B-cell lymphoma who received rituximab-based therapy

BACKGROUND/AIMS

This study investigated the expression of nuclear factor κB (NF-κB) and the chemokine receptor (CXCR4) in patients with diffuse large B-cell lymphoma (DLBCL) who received rituximab-based therapy.

METHODS

Seventy patients with DLBCL and treated with rituximab-CHOP (R-CHOP) were included, and immunohistochemistry was performed to determine the expression of NF-κB (IκB kinase α, p50, and p100/p52) and CXCR4. To classify DLBCL cases as germinal center B-cell-like (GCB) and non-GCB, additional immunohistochemical expression of CD10, bcl-6, or MUM1 was used in this study. The expression was divided into two groups according to the intensity score (negative, 0 or 1+; positive, 2+ or 3+).

RESULTS

The median age of the patients was 66 years (range, 17 to 87), and 58.6% were male. Twenty-seven patients (38.6%) had stage III or IV disease at diagnosis. Twenty-three patients (32.9%) were categorized as high or high-intermediate risk according to their International Prognostic Indexs (IPIs). The overall incidence of bone marrow involvement was 5.7%. Rates of positive NF-κB and CXCR4 expression were 84.2% and 88.6%, respectively. High NF-κB expression was associated with CXCR4 expression (p = 0.002), and 56 patients (80.0%) showed coexpression. However, the expression of NF-κB or CXCR4 was not associated with overall survival and EFS. On multivariate analysis that included age, gender, performance status, stage, and the IPI, no significant association between the grade of NF-κB or CXCR4 expression and survival was observed.

CONCLUSIONS

The current study suggests that the tissue expression of NF-κB and CXCR4 may not be an independent prognostic marker in DLBCL patients treated with R-CHOP.

Influence of NK cell count on the survival of patients with diffuse large B-cell lymphoma treated with R-CHOP

Background

Although adding rituximab to the chemotherapy regimen of cyclophosphamide, vincristine, doxorubicin, and prednisone (R-CHOP) has improved clinical outcomes of patients with diffuse large B-cell lymphoma (DLBCL), several recent studies have shown that the effect of rituximab is dominantly in the non-germinal center (non-GC) subtype compared to the germinal center (GC) subtype. Natural killer (NK) cell count, a surrogate marker of immune status, is associated with clinical outcomes in DLBCL patients in the rituximab era. We investigated whether the impact of NK cells on clinical outcomes differed according to the immunophenotype of DLBCL.

Methods

This study analyzed 72 DLBCL patients treated with R-CHOP between January 2010 and January 2014.

Results

Low NK cell counts (<100/µL) were associated with poor progression-free survival (PFS) and overall survival (OS) compared to high NK cell counts. In multivariate analysis, low NK cell count was an independent prognostic factor for PFS and OS. However, survival did not significantly differ between the GC and non-GC subtypes. We examined the clinical influence of NK cells according to the immunophenotype and found that low NK cell counts were significantly associated with poor PFS and OS in non-GC cases, but not in GC cases.

Conclusion

Low NK cell counts at diagnosis are associated with poor clinical outcomes in DLBCL patients treated with R-CHOP therapy. However, the impact is significant only in non-GC subtype DLBCL, not in the GC subtype.

Both FOXP1 and p65 expression are adverse risk factors in diffuse large B-cell lymphoma: a retrospective study in China

The purpose of this study was to investigate the clinical significance of FOXP1 and p65 expression in diffuse large B-cell lymphoma (DLBCL). Immunohistochemistry was performed to determine the expression of FOXP1 and p65 protein in 92 DLBCL tissues and analyze their correlations with clinicopathological features or prognosis of patients. The survival was assessed by the Kaplan-Meier method and proportional hazards model. Results showed that positive FOXP1 expression was detected in 68 (73.9%) cases and positive p65 expression was detected in 56 (60.9%) cases. There were 46 (50.0%) co-expression of FOXP1 and p65 protein in all cases, a positive correlation between the expression of FOXP1 and p65 was noted (r=0.234, p=0.025). The status of FOXP1 was correlated with patient's age, worse performance status score, higher lactate dehydrogenase levels and International Prognostic Index (IPI) factor score. The status of p65 was correlated with patient's age, B symptom and higher IPI factor scores. Both FOXP1 and p65 protein expression were associated with the non-GCB phenotype (p=0.001 or 0.000). The Kaplan-Meier curves showed that both FOXP1 and p65 expression were associated with poor survival of patients. Meanwhile, FOXP1+/p65+ subgroup had the worst PFS (p=0.012) and OS (p=0.030), whereas the FOXP1-/p65- subgroup had the best prognosis. Thus, immunohistochemical assessment of both FOXP1 and p65 status in DLBCL tissues may be a valuable approach for predicting the survival of DLBCL patients.

MicroRNA-21 regulates the sensitivity of diffuse large B-cell lymphoma cells to the CHOP chemotherapy regimen

Numerous studies have demonstrated that microRNA-21 (miR-21), as an oncogene, is involved in the occurrence of many types of tumor and the sensitivity of tumor cells to chemotherapeutic drugs. In the present study, we investigated whether miR-21 is involved in regulating the sensitivity of the diffuse large B-cell lymphoma (DLBCL) cell line CRL2631 to the cyclophosphamide, vincristine, Adriamycin, and prednisone (CHOP) chemotherapeutic regimen. Knockdown of miR-21 with antisense oligonucleotides significantly increased the cytotoxic effects of the CHOP regimen in CRL2631 cells. A luciferase reporter assay showed that PTEN is a target gene of miR-21 in CRL2631 cells, and subsequent experiments demonstrated that miR-21 impacts the PI3K/AKT signaling pathway through the regulation of PTEN, thereby affecting cellular sensitivity to the CHOP chemotherapeutic regimen. Furthermore, knockdown of NF-κB decreased miR-21 expression and sensitized CRL2631 cells to CHOP treatment. These results provide evidence that it may be possible to overcome microRNA-based DLBCL drug resistance.

Curcumin improves the antitumor effect of X-ray irradiation by blocking the NF-κB pathway: an in-vitro study of lymphoma

Curcumin, a phenolic compound from the rhizomes of Curcuma longa, inhibits the growth of a variety of malignant cell types including lymphoma cells. We investigated the role of curcumin in modulating the response of Burkitt's lymphoma cells to ionizing radiation (IR) in vitro and explored the mechanisms that mediated this effect. We treated three Burkitt's lymphoma cell lines with vehicle, curcumin, IR, and curcumin in combination with IR. Cell viability, apoptosis, and cell cycle distribution were determined to ascertain the radiosensitization effect of curcumin. Nuclear factor-kappa B (NF-κB) activation was assessed by nuclear translocation of p65. Apoptosis-related proteins were monitored by western blot assay and real-time RT-PCR. Pretreatment of curcumin sensitized lymphoma cells to IR-induced apoptosis and increased G2/M phase arrest in the cell cycle distribution. Accordingly, the antiapoptotic Bcl-xL protein, cell cycle modulating protein CDC2, and cyclin B1 were downregulated by the curcumin treatment. IR activated NF-κB as evidenced by an increased nuclear p65 translocation and cytoplasmic IκBα expression. However, pretreatment with curcumin significantly decreased the nuclear translocation of p65 and cytoplasmic IκBα degradation. Survivin and hexokinase II, downstream effectors of NF-κB that mediate the antiapoptotic effect of NF-κB, were suppressed by the pretreatment of curcumin. These observations suggest that the activated NF-κB pathway plays a prosurvival role in Burkitt's lymphoma in response to IR. Curcumin blocks this pathway and has therapeutic potential for improving the antitumor effects of radiotherapy.

Activation of mammalian target of rapamycin in diffuse large B-cell lymphoma: a clinicopathological study

Cell signaling by a highly conserved serine/threonine kinase mammalian target of rapamycin (mTOR) has been shown to play a critical role in cell proliferation. We analyzed the immunohistochemical expression of mTOR, pmTOR and bcl-2 in 55 patients with diffuse large B-cell lymphoma and correlated it with clinical parameters and clinical outcomes. On univariate analysis, higher expression of mTOR was associated with male gender, older age, and higher IPI score. Patients with a high total mTOR score showed a trend toward shorter survival. Based on our results we propose that use of targeted therapy with mTOR inhibitors, in a subset of diffuse large B-cell lymphoma patients may help improve patient survival.

Oxidative stress and redox state-regulating enzymes have prognostic relevance in diffuse large B-cell lymphoma

Background

Oxidative stress and redox-regulating enzymes may have roles both in lymphomagenesis and resistance to lymphoma therapy. Previous studies from the pre-rituximab era suggest that antioxidant enzyme expression is related to prognosis in diffuse large B-cell lymphoma (DLBCL), although these results cannot be extrapolated to patient populations undergoing modern treatment modalities. In this study we assessed expression of the oxidative stress markers 8-hydroxydeoxyguanosine (8-OHdG) and nitrotyrosine and the antioxidant enzymes thioredoxin (Trx), manganese superoxide dismutase (MnSOD) and glutamate-cysteine ligase (GCL) via immunohistochemistry in 106 patients with DLBCL. All patients were treated with CHOP-like therapy combined with rituximab. Immunostaining results were correlated with progression-free survival, disease-specific survival and traditional prognostic factors of DLBCL.

Results

Strong 8-OHdG immunostaining intensity was associated with extranodal involvement (p = 0.00002), a high International Prognostic Index (p = 0.002) and strong Trx (p = 0.011) and GCL (p = 0.0003) expression. Strong Trx staining intensity was associated with poor progression-free survival (p = 0.046) and poor disease-specific survival (p = 0.015). Strong GCL immunostaining intensity predicted poor progression-free survival (p = 0.049). Patients with either strong Trx or strong nitrotyrosine expression showed significantly poorer progression-free survival (p = 0.003) and disease-specific survival (p = 0.031) compared with the other patients.

Conclusions

The redox state-regulating enzymes GCL and Trx are promising markers in the evaluation of DLBCL prognosis in the era of modern immunochemotherapy.

Microarray gene expression analysis of fixed archival tissue permits molecular classification and identification of potential therapeutic targets in diffuse large B-cell lymphoma

Refractory/relapsed diffuse large B-cell lymphoma (DLBCL) has a poor prognosis. Novel drugs targeting the constitutively activated NF-κB pathway characteristic of ABC-DLBCL are promising, but evaluation depends on accurate activated B cell-like (ABC)/germinal center B cell-like (GCB) molecular classification. This is traditionally performed on gene microarray expression profiles of fresh biopsies, which are not routinely collected, or by immunohistochemistry on formalin-fixed, paraffin-embedded (FFPE) tissue, which lacks reproducibility and classification accuracy. We explored the possibility of using routine archival FFPE tissue for gene microarray applications. We examined Affymetrix HG U133 Plus 2.0 gene expression profiles from paired archival FFPE and fresh-frozen tissues of 40 ABC/GCB-classified DLBCL cases to compare classification accuracy and test the potential for this approach to aid the discovery of therapeutic targets and disease classifiers in DLBCL. Unsupervised hierarchical clustering of unselected present probe sets distinguished ABC/GCB in FFPE with remarkable accuracy, and a Bayesian classifier correctly assigned 32 of 36 cases with >90% probability. Enrichment for NF-κB genes was appropriately seen in ABC-DLBCL FFPE tissues. The top discriminatory genes expressed in FFPE separated cases with high statistical significance and contained novel biology with potential therapeutic insights, warranting further investigation. These results support a growing understanding that archival FFPE tissues can be used in microarray experiments aimed at molecular classification, prognostic biomarker discovery, and molecular exploration of rare diseases.

Epstein-Barr virus latent membrane protein-1 protects B-cell lymphoma from rituximab-induced apoptosis through miR-155-mediated Akt activation and up-regulation of Mcl-1

Rituximab is a CD20-targeted monoclonal antibody widely used in the treatment of B-cell lymphoma. Previously, we have shown that Epstein-Barr virus (EBV) latent membrane protein-1 (LMP1) increases chemoresistance in malignant cancer cells. In this study we examined the effects of LMP1 on the response of B-cell lymphoma cell lines to rituximab. Here we show for the first time that LMP1 activates the Akt pathway and up-regulates Mcl-1 through miR-155 expression, which contributes to the survival of rituximab-treated B-cell lymphoma cells. Furthermore, Akt inhibition or knockdown of Mcl-1 and miR-155 was found to be an efficient strategy to overcome rituximab resistance caused by LMP1 expression. Thus, we propose Akt and Mcl-1 and miR-155 as molecular targets for therapeutic intervention in the treatment of EBV-associated B-cell lymphoma with rituximab.

HDAC inhibitors and decitabine are highly synergistic and associated with unique gene-expression and epigenetic profiles in models of DLBCL

Interactions between histone deacetylase inhibitors (HDACIs) and decitabine were investigated in models of diffuse large B-cell lymphoma (DLBCL). A number of cell lines representing both germinal center B-like and activated B-cell like DLBCL, patient-derived tumor cells and a murine xenograft model were used to study the effects of HDACIs and decitabine in this system. All explored HDACIs in combination with decitabine produced a synergistic effect in growth inhibition and induction of apoptosis in DLBCL cells. This effect was time dependent, mediated via caspase-3 activation, and resulted in increased levels of acetylated histones. Synergy in inducing apoptosis was confirmed in patient-derived primary tumor cells treated with panobinostat and decitabine. Xenografting experiments confirmed the in vitro activity and tolerability of the combination. We analyzed the molecular basis for this synergistic effect by evaluating gene-expression and methylation patterns using microarrays, with validation by bisulfite sequencing. These analyses revealed differentially expressed genes and networks identified by each of the single treatment conditions and by the combination therapy to be unique with few overlapping genes. Among the genes uniquely altered by the combination of panobinostat and decitabine were VHL, TCEB1, WT1, and DIRAS3.

Clinical significance of nuclear factor κB expression in primary gastrointestinal diffuse large B-cell lymphoma

AIM: To investigate the clinical significance of nuclear factor κB (NF-κB) expression in primary gastrointestinal diffuse large B-cell lymphoma (PGI-DLBCL).

METHODS: Immunohistochemical staining was used to detect the expression of CD10, Bcl-6, Mum-1 and NF-κB p65 in PGI-DLBCL. The relationship of NF-κB p65 expression with tumor subtype, biological behavior and prognosis was analyzed.

RESULTS: Of 54 cases of PGI-DLBCL detected, 28% were positive for CD10, 69% positive for Bcl-6, and 81% positive for Mum-1; 19 were classified as germinal center B-cell-like (GCB) subtype, and 35 as activated B-cell like (ABC) subtype. The positive rate of NF-κB p65 expression in PGI-DLBCL was 72% (39/54). The positive rate of NF-κB p65 expression was significantly higher in ABC-DLBCL than in GCB-DLBCL (74.4% vs 25.6%, P < 0.05). NF-κB p65 expression was correlated with extranodal invasion site in PGI-DLBCL (P < 0.05). The overall survival time of NF-κB p65-negative PGI-DLBCL patients was longer than that of NF-κB p65-positive ones (45.8 mo ± 35.9 mo vs 20.3 mo ± 29.3 mo, P < 0.05).

CONCLUSION: NF-κB p65 expression was positively correlated with the subtype, development, and invasion of PGI-DLBCL. NF-κB p65 can be used as a prognostic factor for PGI-DLBCL and may represent a new molecular target for the therapy of GI-DLBCL.

Clear cell variant of diffuse large B-cell lymphoma: a case report

Introduction

Diffuse large B-cell lymphoma is a diffuse proliferation of large neoplastic B lymphoid cells with a nuclear size equal to or exceeding the normal macrophage nuclei. We report a case of a clear cell variant of diffuse large B-cell lymphoma involving a lymph node in the neck, which was clinically suspected of being metastatic carcinoma.

Case presentation

A 39-year-old Caucasian ethnic Albanian man from Kosovo presented with a rapidly enlarging lymph node in his neck, but he also disclosed B symptoms and fatigue. A cytological aspirate of the lymph node revealed pleomorphic features. Our patient underwent a cervical lymph node biopsy (large excision). The mass was homogeneously fish-flesh, pale white tissue replacing almost the whole structure of the lymph node. The lymph node biopsy showed a partial alveolar growth pattern, which raised clinical suspicion that it was an epithelial neoplasm. With regard to morphological and phenotypic features, we discovered large nodules in diffuse areas, comprising large cells with slightly irregular nuclei and clear cytoplasm admixed with a few mononuclear cells. In these areas, there was high mitotic activity, and in some areas there were macrophages with tangible bodies. Staining for cytokeratins was negative. These areas had the following phenotypes: cluster designation marker 20 (CD20) positive, B-cell lymphoma (Bcl)-2-positive, Bcl-6^-, CD5^-, CD3^-, CD21⁺ (in alveolar patterns), prostate-specific antigen-negative, human melanoma black marker 45-negative, melanoma marker-negative, cytokeratin-7-negative and multiple myeloma marker 1-positive in about 30% of cells, and exhibited a high proliferation index marker (Ki-67, 80%).

Conclusion

According to the immunohistochemical findings, we concluded that this patient has a clear cell variant of diffuse large B-cell lymphoma of activated cell type, post-germinal center cell origin. Our patient is undergoing R-CHOP chemotherapy treatment.

NF-kappaB as a prognostic marker and therapeutic target in chronic lymphocytic leukemia

Chronic lymphocytic leukemia is the most common adult leukemia and is currently incurable with conventional chemotherapeutic agents. Over the last few years, significant discoveries have been made regarding the biology that underpins this disease. These new insights have allowed us to develop more rational prognostic tools and identify promising novel therapeutic targets. In this review, we highlight the importance of both constitutive and inducible DNA binding of the transcription factor NF-kappaB in chronic lymphocytic leukemia. We describe the current knowledge regarding the activity and function of specific NF-kappaB subunits in this disease, and discuss the complex mechanisms that regulate NF-kappaB activation in vivo. In addition, we provide compelling evidence for the utility of the NF-kappaB subunit, Rel A, as a prognostic marker and as a therapeutic target in this disease, and we also describe how this protein may contribute to the drug resistance commonly encountered with this condition.