Clinical Significance of BCL2, C-MYC, and BCL6 Genetic Abnormalities, Epstein-Barr Virus Infection, CD5 Protein Expression, Germinal Center B Cell/Non-Germinal Center B-Cell Subtypes, Co-expression of MYC/BCL2 Proteins and Co-expression of MYC/BCL2/BCL6 Proteins in Diffuse Large B-Cell Lymphoma: A Clinical and Pathological Correlation Study of 120 Patients

Expression and Clinical Significance of Ki-67, CD10, BCL6, MUM1, c-MYC, and EBV in Diffuse Large B Cell Lymphoma Patients

INTRODUCTION

Diffuse large B cell lymphoma (DLBCL) is the most common type of non-Hodgkin lymphoma (NHL) in adults. Although studies regarding the association between the expression of Ki-67, CD10, BCL6, and MUM1 proteins, as well as c-MYC amplification and EBV status with clinicopathologic characteristics have rapidly progressed, their co-expression and prognostic role remain unsatisfactory. Therefore, this study aimed to investigate the association between the expression of all markers and clinicopathologic features and their prognostic value in DLBCL. Also, the co-expression of markers was investigated.

METHODS

The protein expression levels and prognostic significance of Ki-67, CD10, BCL6, and MUM1 were investigated with clinical follow-up in a total of 53 DLBCL specimens (including germinal center B [GCB] and activated B cell [ABC] subtypes) as well as adjacent normal samples using immunohistochemistry (IHC). Besides, the clinical significance and prognostic value of c-MYC and EBV status were also evaluated through chromogenic in situ hybridization (CISH), and their correlation with other markers was also assessed.

RESULTS

The results demonstrated a positive correlation between CD10 and BCL6 expression, with both markers being associated with the GCB subtype ( P< 0.001 and P =0.001, respectively). Besides, we observe a statistically significant association between MUM1 protein expression and clinicopathologic type ( P< 0.005) as well as a positive association between c-MYC and recurrence ( P =0.028). Our survival analysis showed that patients who had responded to R-CHOP treatment had better overall survival (OS) and progression-free survival (PFS) than those who did not.

CONCLUSION

Collectively, this study's results add these markers' value to the existing clinical understanding of DLBCL. However, further investigations are needed to explore markers' prognostic and biological roles in DLBCL patients.

Alternative genetic alterations of MYC, BCL2, and/or BCL6 in high-grade B-cell lymphoma (HGBL) and diffuse large B-cell lymphoma (DLBCL): Can we identify different prognostic subgroups?

High-grade B-cell lymphoma (HGBL)/diffuse large B-cell lymphoma (DLBCL) with rearrangements (R) in MYC and BCL2 and/or BCL6 are correlated with poor prognosis. Little is known about the impact of other genetic alterations (gain (G) or amplification (A)) of these genes. The aim of the study was to investigate whether we can identify new prognostic subgroups. Fluorescence in situ hybridization (FISH) results from 169 HGBL/DLBCL were retrospectively categorized into: (1) concurrent MYC-R and BCL2-R and/or BCL6-R-samples with MYC-R and BCL2-R (+/- BCL6-R); n = 21, and HGBL/DLBCL with MYC-R and BCL6-R; n = 11; (2) concurrent R and G/A in MYC and BCL2 and/or BCL6 called "alternative HGBL/DLBCL"-samples with (n = 16) or without (n = 6) BCL2 involvement; (3) BCL2 and/or BCL6 alterations without MYC involvement (n = 35); (4) concurrent G/A in MYC and BCL2 and/or BCL6 without R (n = 25); and (5) "No alterations" (n = 55). Patients with HGBL/DLBCL-MYC/BCL2 and "alternative" HGBL/DLBCL (with BCL2 involvement) had significantly worse survival rates compared to the "no alterations" group. G/A of these genes in the absence of rearrangements did not show any prognostic significance. HGBL/DLBCL with MYC-R and BCL6-R without BCL2 involvement showed a better survival rate compared to HGBL/DLBCL-MYC/BCL2. According to immunohistochemistry, "double/triple" expression (DEL/TEL) did not show a significantly worse outcome compared to absent DEL/TEL. This study highlights the continued value of FISH assessment of MYC, BCL2, and BCL6 in the initial evaluation of HGBL/DLBCL with different survival rates between several genetic subgroups.

The RNA helicase DDX3 and its role in c-MYC driven germinal center-derived B-cell lymphoma

DDX3X is an RNA helicase with many functions in RNA metabolism such as mRNA translation, alternative pre-mRNA splicing and mRNA stability, but also plays a role as a regulator of transcription as well as in the Wnt/beta-catenin- and Nf-κB signaling pathways. The gene encoding DDX3X is located on the X-chromosome, but escapes X-inactivation. Hence females have two active copies and males only one. However, the Y chromosome contains the gene for the male DDX3 homologue, called DDX3Y, which has a very high sequence similarity and functional redundancy with DDX3X, but shows a more restricted protein expression pattern than DDX3X. High throughput sequencing of germinal center (GC)-derived B-cell malignancies such as Burkitt Lymphoma (BL) and Diffuse large B-cell lymphoma (DLBCL) samples showed a high frequency of loss-of-function (LOF) mutations in the DDX3X gene revealing several features that distinguish this gene from others. First, DDX3X mutations occur with high frequency particularly in those GC-derived B-cell lymphomas that also show translocations of the c-MYC proto-oncogene, which occurs in almost all BL and a subset of DLBCL. Second, DDX3X LOF mutations occur almost exclusively in males and is very rarely found in females. Third, mutations in the male homologue DDX3Y have never been found in any type of malignancy. Studies with human primary GC B cells from male donors showed that a loss of DDX3X function helps the initial process of B-cell lymphomagenesis by buffering the proteotoxic stress induced by c-MYC activation. However, full lymphomagenesis requires DDX3 activity since an upregulation of DDX3Y expression is invariably found in GC derived B-cell lymphoma with DDX3X LOF mutation. Other studies with male transgenic mice that lack Ddx3x, but constitutively express activated c-Myc transgenes in B cells and are therefore prone to develop B-cell malignancies, also showed upregulation of the DDX3Y protein expression during the process of lymphomagenesis. Since DDX3Y is not expressed in normal human cells, these data suggest that DDX3Y may represent a new cancer cell specific target to develop adjuvant therapies for male patients with BL and DLBCL and LOF mutations in the DDX3X gene.

[Clinical features and prognosis of 166 cases of MYC/BCL2 double-expression diffuse large B-cell lymphoma]

Objective: To investigate the clinical features and prognosis of MYC/BCL2 double-expression diffuse large B-cell lymphoma (DEL) . Methods: The clinical data, including clinical characteristics, survival, and prognostic factors, of 166 patients with DEL treated at Peking University Third Hospital from January 2016 to December 2020 were retrospectively analyzed. Results: A total of 410 patients with diffuse large B-cell lymphoma were collected, including 166 cases (40.5%) of DEL. There were 82 males and 84 females with a median age of 63.5 (21-95) years at diagnosis. A total of 110 patients (66.3%) were aged over 60 years at initial diagnosis, 106 patients (106/163, 65.0%) had elevated lactate dehydrogenase (LDH) at diagnosis, 74 patients (74/160, 46.2%) had β(2) microglobulin level over 3 mg/L at diagnosis, and 107 patients (107/163, 65.6%) had≥2 extranodal involvement. Sixty-five patients (65/166, 39.2%) had B symptoms, 131 patients (131/165, 79.4%) had stage Ⅲ and Ⅳ disease at initial diagnosis, 41 patients (41/161, 25.5%) had an International Prognostic Index (IPI) score of 0-2 at initial diagnosis, and 38 patients (38/161, 23.6%) had an IPI score of 3 at initial diagnosis. Eighty-two patients (82/161, 50.9%) had an IPI score of 4-5 at initial diagnosis. Nine (9/56, 16.1%) patients with DEL had MYD88 and CD79B mutations. Univariate analysis showed that age over 60 years (P=0.004) , increased β(2) microglobulin level (P=0.002) , and high IPI score (P=0.003) were associated with poor overall survival (OS) . Increased β(2) microglobulin level (P=0.031) , LDH level (P=0.017) , stage Ⅲ-Ⅳ (P=0.001) , high IPI score (P=0.013) , immunohistochemical p53 mutation (P=0.049) , and PIM1 mutation (P=0.039) were associated with poor progression-free survival (PFS) . Multivariate analysis showed that IPI score of 4-5 was an independent risk factor for the prognosis of DEL (HR=2.622, 95% CI 1.398-4.917, P=0.003) . Survival analysis showed that there was a significant difference in the PFS between patients with DEL and those without DEL (65.6% vs 75.1%, P=0.002) . However, there was no significant difference in the OS (81.8% vs 83.6%, P=0.226) . In patients with DEL, the overall response rate of R-EPOCH regimen was higher than that of RCHOP or RCHOP-like regimen (81.5% vs 63.4%, P=0.004) . Conclusion: DEL is a group of aggressive lymphomas with relatively poor PFS. The R-EPOCH regimen may improve the overall prognosis of patients.

Targeting Oncogene Promoters and Ribosomal RNA Biogenesis by G-Quadruplex Binding Ligands Translate to Anticancer Activity

G-Quadruplex (GQ) nucleic acids are promising therapeutic targets in anticancer research due to their structural robustness, polymorphism, and gene-regulatory functions. Here, we presented the structure-activity relationship of carbazole-based monocyanine ligands using region-specific functionalization with benzothiazole (TCA and TCZ), lepidine (LCA and LCZ), and quinaldine (QCA and QCZ) acceptor moieties and evaluated their binding profiles with different oncogenic GQs. Their differential turn-on fluorescence emission upon GQ binding confirmed the GQ-to-duplex selectivity of all carbazole ligands, while the isothermal titration calorimetry results showed selective interactions of TCZ and TCA to c-MYC and BCL-2 GQs, respectively. The aldehyde group in TCA favors stacking interactions with the tetrad of BCL-2 GQ, whereas TCZ provides selective groove interactions with c-MYC GQ. Dual-luciferase assay and chromatin immunoprecipitation (ChIP) showed that these molecules interfere with the recruitment of specific transcription factors at c-MYC and BCL-2 promoters and stabilize the promoter GQ structures to inhibit their constitutive transcription in cancer cells. Their intrinsic turn-on fluorescence response with longer lifetimes upon GQ binding allowed real-time visualization of GQ structures at subcellular compartments. Confocal microscopy revealed the uptake of these ligands in the nucleoli, resulting in nucleolar stress. ChIP studies further confirmed the inhibition of Nucleolin occupancy at multiple GQ-enriched regions of ribosomal DNA (rDNA) promoters, which arrested rRNA biogenesis. Therefore, carbazole ligands act as the "double-edged swords" to arrest c-MYC and BCL-2 overexpression as well as rRNA biogenesis, triggering synergistic inhibition of multiple oncogenic pathways and apoptosis in cancer cells.

Analysis of the Clinicopathologic Characteristics and Prognosis of Head and Neck Lymphoma

Statistical reports on non-Hodgkin's lymphoma (NHL) of the head and neck combining clinical medicine with pathology are rare. To provide a basis for prognosis prediction and individualized treatment, we will investigate the clinicopathologic characteristics and prognosis of lymphoma in the head and neck region. Four hundred sixty-one patients with NHL in the head and neck region diagnosed through histological biopsy were retrospectively analyzed. Fluorescence in situ hybridization (FISH) and immunohistochemistry (IHC) were performed in all cases to evaluate the genetic status and protein expression levels. Patients were followed up by telephone. The prevalence rate of primary extranodal NHL (PENHL) in the head and neck region was 44.62% (166/372). The incidence of extranodal lymphoma accounted for 36.66% (169/461) of all head and neck lymphomas. Among the cases of PENHL of the head and neck, diffuse large B-cell lymphoma (DLBCL) (60/76, 78.95%) and extranodal NK/T-cell lymphoma, nasal type (ENKTCL) (21/24, 87.5%) were the most common subtypes originating from B-cell lymphoma (BCL) and T-cell lymphoma (TCL), respectively. The most common sites of nodal and extranodal onset were neck lymph nodes and the gastrointestinal tract, respectively. The most common and primary locations of BCL and TCL were the tonsils and nasal cavity, respectively. The 3-year survival rates of PENHL, ENKTCL, and DLBCL of the head and neck were 42%, 28.57%, and 41.67%, respectively, and the 5-year survival rates were 24%, 19.05%, and 20%, respectively. Survival analysis showed that male sex was a risk factor (HR = 5.421; 95% CI, 1.164-25.267; p < 0.05) and that comprehensive treatment was a protective factor (HR = 0.117; 95% CI, 0.025-0.545; p < 0.05) against extranodal DLBCL in the head and neck region. Bone marrow involvement was a risk factor for PENHL of the head and neck (HR = 5.072; 95% CI, 1.17-21.991; p < 0.05). The purpose of this review is to show that PENHL of the head and neck with high incidence deserves more attention, and a model of multidisciplinary diagnosis and treatment should be adopted.

The Incidence and Treatment Response of Double Expression of MYC and BCL2 in Patients with Diffuse Large B-Cell Lymphoma: A Systematic Review and Meta-Analysis

MYC/BCL2 protein co-expression (i.e., double expressor) has been shown to be a negative predictor of outcome in diffuse large B-cell lymphoma (DLBCL). We aimed to establish the incidence of double expressor status in patients with de novo DLBCL and identify the predictive value of this biomarker on treatment response through systematic review and meta-analysis. PubMed and Embase were searched for studies published through December 2019 that reported proportions of double expressor DLBCL. The pooled proportions of MYC and BCL2 expression, both alone and in combination, were computed using the inverse variance method for calculating weights and by the DerSimonian-Laird method. The pooled odds ratios (ORs) of complete remission (CR) rate were calculated, and meta-regression analysis was conducted to explore heterogeneity. Forty-one studies (7054 patients) were included. The pooled incidence of double expressor status in DLBCL was 23% (95% confidence interval [CI], 20-26%), with an adjusted estimate of 31% (95% CI, 27-36%). Neither MYC/BCL2 protein cutoff values, race, mean, or median age of included patients, or overall study quality was a significant factor of heterogeneity (p ≥ 0.20). Cases without double expressor status demonstrated a higher probability of CR to rituximab, cyclophosphamide, doxorubicin, vincristine, and prednisone treatment (OR, 2.69; 95% CI, 1.55-4.67). Our results reaffirm the predictive power of this important biomarker.

Clinical and Molecular Properties of Human Immunodeficiency Virus-Related Diffuse Large B-Cell Lymphoma

Non-Hodgkin lymphoma is the most common malignancy affecting people living with HIV (PLWH). Among its several subtypes, diffuse large B-cell lymphoma (DLBCL) is an important manifestation within the HIV-infected compartment of the population. Since HIV is able to modulate B cells and promote lymphomagenesis through direct and indirect mechanisms, HIV-related DLBCL has specific characteristics. In this review, we address the clinical and molecular properties of DLBCL disease in the context of HIV infection, as well as the mechanisms by which HIV is able to modulate B lymphocytes and induce their transformation into lymphoma.

Clinicopathological and genetic characteristics of diffuse large B-cell lymphoma of the oropharyngeal and maxillofacial region

OBJECTIVES

The study was aimed to analyze the clinicopathological and molecular pathological features of diffuse large B-cell lymphoma (DLBCL) in the oropharyngeal and maxillofacial region.

SUBJECTS AND METHODS

A retrospective review was performed with 36 patients who were diagnosed with primary DLBCL of the oropharyngeal and maxillofacial region from 2009 to 2017 in the Department of Pathology at the Hospital of Stomatology, Wuhan University. Immunohistochemistry and fluorescence in situ hybridization were performed.

RESULTS

Gene rearrangements of BCL2, BCL6, and MYC were observed in 5.6%, 33.3%, and 22.2%, respectively, including two double-hit and one triple-hit DLBCL (8.3%). There was a significant correlation between MYC protein expression and gene translocation (rs = 0.679, p < .001). However, 25% of cases with MYC rearrangement showed low MYC protein expression. In univariate analysis, MYC protein expression, BCL2 rearrangement, MYC rearrangement, and double/triple-hit DLBCL were associated with shorter overall survival, whereas only MYC protein expression was an independent prognostic value in multivariate model.

CONCLUSIONS

MYC protein expression was an essential prognostic marker of DLBCL in the oropharyngeal and maxillofacial region. Notably, immunohistochemical staining of MYC, BCL2, and BCL6 could not predict their gene rearrangements, although MYC protein expression was correlated with gene translocation.

The Spectrum of MYC Alterations in Diffuse Large B-Cell Lymphoma

MYC, as a powerful transcription factor, plays a vital role in various cancers. The clinical significance of MYC alterations in diffuse large B-cell lymphoma (DLBCL) has been investigated for a long time. In this study, we comprehensively summarize the different alterations of MYC in DLBCL, including MYC overexpression, MYC translocations, MYC mutations, and increased gene copy number of MYC. Noteworthy, lone MYC overexpression or MYC translocation is not significantly associated with poor clinical outcomes, and their detrimental effects depend on the genetic alterations of BCL2 or BCL6. Both double-expressor DLBCL (DE-DLBCL), defined as overexpression of MYC and BCL2 proteins, and double-hit lymphoma (DHL), defined as a dual translocation of MYC together with BCL2 or BCL6, represent the distinct subgroups of DLBCL with inferior clinical outcomes. The mechanism may be that MYC activation induces cell proliferation, without the threat of the apoptotic brake in the presence of BCL2 overexpression. In addition, most of MYC mutations are present with favorable prognosis, and the nonsignificant effect of MYC copy number amplification has been observed. It has been proved that cyclophosphamide, doxorubicin, vincristine, and prednisone plus rituximab show limited effects for DHL or DE-DLBCL, and the rituximab plus dose-adjusted etoposide, prednisone, vincristine, cyclophosphamide, and doxorubicin seem to be efficacious for DHL. The novel therapy is urgently needed for clinical improvement in DHL and DE-DLBCL.

B Cell Lymphoma

B cell development and activation are accompanied by dynamic genetic alterations including V(D)J rearrangements and immunoglobulin-gene somatic hypermutation and class-switch recombination. Abnormalities in these genetic events can cause chromosomal translocations and genomic mutations, leading to altered expression and function of genes involved in B cell survival or proliferation and consequently B lymphomagenesis. In fact, B cell lymphoma accounts for 95% of the lymphomas. In this chapter, we summarize the morphology, immunophenotypes, clinical features, genetic defects that cause the malignancies, treatments, and prognosis of the most prevalent types of B cell lymphomas, including typical precursor B cell malignance (B-ALL/LBL) and mature B cell lymphoma (Hodgkin lymphoma and B cell non-Hodgkin lymphoma).