Pathogenetic importance and therapeutic implications of NF-κB in lymphoid malignancies

Research progress on the mechanism of common inflammatory pathways in the pathogenesis and development of lymphoma

In recent years, the incidence and mortality rates of lymphoma have gradually increased worldwide. Tumorigenesis and drug resistance are closely related to intracellular inflammatory pathways in lymphoma. Therefore, understanding the biological role of inflammatory pathways and their abnormal activation in relation to the development of lymphoma and their selective modulation may open new avenues for targeted therapy of lymphoma. The biological functions of inflammatory pathways are extensive, and they are central hubs for regulating inflammatory responses, immune responses, and the tumour immune microenvironment. However, limited studies have investigated the role of inflammatory pathways in lymphoma development. This review summarizes the relationship between abnormal activation of common inflammatory pathways and lymphoma development to identify precise and efficient targeted therapeutic options for patients with advanced, drug-resistant lymphoma.

Positive selection CRISPR screens reveal a druggable pocket in an oligosaccharyltransferase required for inflammatory signaling to NF-κB

Nuclear factor κB (NF-κB) plays roles in various diseases. Many inflammatory signals, such as circulating lipopolysaccharides (LPSs), activate NF-κB via specific receptors. Using whole-genome CRISPR-Cas9 screens of LPS-treated cells that express an NF-κB-driven suicide gene, we discovered that the LPS receptor Toll-like receptor 4 (TLR4) is specifically dependent on the oligosaccharyltransferase complex OST-A for N-glycosylation and cell-surface localization. The tool compound NGI-1 inhibits OST complexes in vivo, but the underlying molecular mechanism remained unknown. We did a CRISPR base-editor screen for NGI-1-resistant variants of STT3A, the catalytic subunit of OST-A. These variants, in conjunction with cryoelectron microscopy studies, revealed that NGI-1 binds the catalytic site of STT3A, where it traps a molecule of the donor substrate dolichyl-PP-GlcNAc2-Man9-Glc3, suggesting an uncompetitive inhibition mechanism. Our results provide a rationale for and an initial step toward the development of STT3A-specific inhibitors and illustrate the power of contemporaneous base-editor and structural studies to define drug mechanism of action.

A phase 1-2 trial of DA-EPOCH-R plus ixazomib for MYC-aberrant lymphoid malignancies: the DACIPHOR regimen

ABSTRACT

MYC-aberrant non-Hodgkin lymphoma (NHL) is associated with poor outcomes with conventional chemotherapy. Ixazomib is an orally bioavailable proteasome inhibitor that targets drivers of MYC expression and has demonstrated preclinical activity in aggressive MYC-aberrant NHL. We conducted a phase 1/2 study evaluating the safety and efficacy of DA-EPOCH-R with adjunctive ixazomib in aggressive MYC-aberrant NHL. For induction, patients received 6 cycles of DA-EPOCH-R with ixazomib administered twice per 21-day cycle; responders continued weekly ixazomib maintenance for up to 1 year. Primary objectives were to determine the maximum tolerated dose in phase 1 and efficacy of DA-EPOCH-R with ixazomib as measured by 12-month progression-free survival (PFS) rate in phase 2. Thirty-six patients were evaluable for response. Median age was 63 years (range, 31-77) and 44% had double-hit lymphoma (DHL)/triple-hit lymphoma (THL). In phase 1, 3 mg of ixazomib was established as recommended phase 2 dose. Twenty-nine (76.3%) patients completed 6 cycles of DA-EPOCH-R and 25 (65.8%) underwent dose escalations. The ORR after induction was 97% (95% confidence interval, 81-100) with a CR rate of 69%. At median follow-up of 18.8 months, the 12-month PFS and overall survival (OS) rates were 78% and 86%, respectively. For DHL/THL vs dual expressor lymphomas (DEL), 12-month PFS rates were 53% vs 95% and 12-month OS rates were 65% vs 100%, respectively. Grade ≥3 toxicities were predominantly hematologic. Twenty-seven (75%) of patients experienced neuropathy, nearly all low-grade. DA-EPOCH-R induction with adjunctive ixazomib is feasible and appears effective in patients with DEL. This trial was registered at www.clinicaltrials.gov as #NCT02481310.

Siglec-15/sialic acid axis as a central glyco-immune checkpoint in breast cancer bone metastasis

Immunotherapy is a promising approach for treating metastatic breast cancer (MBC), offering new possibilities for therapy. While checkpoint inhibitors have shown great progress in the treatment of metastatic breast cancer, their effectiveness in patients with bone metastases has been disappointing. This lack of efficacy seems to be specific to the bone environment, which exhibits immunosuppressive features. In this study, we elucidate the multiple roles of the sialic acid-binding Ig-like lectin (Siglec)-15/sialic acid glyco-immune checkpoint axis in the bone metastatic niche and explore potential therapeutic strategies targeting this glyco-immune checkpoint. Our research reveals that elevated levels of Siglec-15 in the bone metastatic niche can promote tumor-induced osteoclastogenesis as well as suppress antigen-specific T cell responses. Next, we demonstrate that antibody blockade of the Siglec-15/sialic acid glyco-immune checkpoint axis can act as a potential treatment for breast cancer bone metastasis. By targeting this pathway, we not only aim to treat bone metastasis but also inhibit the spread of metastatic cancer cells from bone lesions to other organs.

Analysis of genomic alterations in primary central nervous system lymphoma

Primary central nervous system lymphoma (PCNSL) is a rare and special type of non-Hodgkin lymphoma with a significantly worse median overall prognosis than that of non-Hodgkin lymphoma outside the brain. Clarifying the genomic characteristics and alterations in PCNSL could provide clues regarding its distinctive pathophysiology and new treatment options. However, current knowledge about the genomics of PCNSL is limited. In this study, next-generation sequencing (NGS) was performed to investigate the genomic profile of PCNSL. Samples from 12 patients diagnosed with PCNSL at our institution were analyzed for gene mutations using NGS. This study showed that missense mutations were the most common mutation type. C > A/G > T accounted for most of the single-base mutations, which reflected the preference of the tumor sample mutation type and may serve as an important prognostic factor. The most significantly mutated gene was myeloid differentiation factor 88 (MYD88) (0.55), followed by CD79B, LRP1B, and PRDM1 (0.36). None of the cases showed a high tumor mutational burden. In addition to the traditional driver genes, we also identified some new possible ones such as MET, PIM1, and RSBN1L. Enrichment analysis revealed that genes mutated in PCNSL were involved in many pathways and functional protein activities, such as the extracellular matrix and adhesion molecules. The most common genetic alterations in PCNSL were identified using NGS. Mutations in multiple genes highlights the complex molecular heterogeneity of PCNSL. Enrichment analysis revealed possible pathogenesis. Further exploration of new driver genes could provide novel insights into diagnosis and precision medicine for PCNSL.

NF-κB subunits direct kinetically distinct transcriptional cascades in antigen receptor-activated B cells

The nuclear factor kappa B (NF-κB) family of transcription factors orchestrates signal-induced gene expression in diverse cell types. Cellular responses to NF-κB activation are regulated at the level of cell and signal specificity, as well as differential use of family members (subunit specificity). Here we used time-dependent multi-omics to investigate the selective functions of Rel and RelA, two closely related NF-κB proteins, in primary B lymphocytes activated via the B cell receptor. Despite large numbers of shared binding sites genome wide, Rel and RelA directed kinetically distinct cascades of gene expression in activated B cells. Single-cell RNA sequencing revealed marked heterogeneity of Rel- and RelA-specific responses, and sequential binding of these factors was not a major mechanism of protracted transcription. Moreover, nuclear co-expression of Rel and RelA led to functional antagonism between the factors. By rigorously identifying the target genes of each NF-κB subunit, these studies provide insights into exclusive functions of Rel and RelA in immunity and cancer.

NF-κB: a mediator that promotes or inhibits angiogenesis in human diseases?

The nuclear factor of κ-light chain of enhancer-activated B cells (NF-κB) signaling pathway, which is conserved in invertebrates, plays a significant role in human diseases such as inflammation-related diseases and carcinogenesis. Angiogenesis refers to the growth of new capillary vessels derived from already existing capillaries and postcapillary venules. Maintaining normal angiogenesis and effective vascular function is a prerequisite for the stability of organ tissue function, and abnormal angiogenesis often leads to a variety of diseases. It has been suggested that NK-κB signalling molecules under pathological conditions play an important role in vascular differentiation, proliferation, apoptosis and tumourigenesis by regulating the transcription of multiple target genes. Many NF-κB inhibitors are being tested in clinical trials for cancer treatment and their effect on angiogenesis is summarised. In this review, we will summarise the role of NF-κB signalling in various neovascular diseases, especially in tumours, and explore whether NF-κB can be used as an attack target or activation medium to inhibit tumour angiogenesis.

Frequent Gene Mutations and Their Possible Roles in the Pathogenesis, Treatment and Prognosis of Primary Central Nervous System Lymphoma

Primary central nervous system lymphoma (PCNSL) is a rare extranodal non-Hodgkin lymphoma with poor prognosis. In recent years, the emergence of genetic subtypes of systematic diffuse large B-cell lymphoma has highlighted the importance of molecular genetics, but large-scale research on the molecular genetics of PCNSL is lacking. Herein, we summarize the frequent gene mutations and discuss the possible pathogenesis of PCNSL. Myeloid differentiation primary response gene 88 (MYD88) and CD79B mutations, which cause abnormal activation of noncanonical nuclear factor-κB, are prominent genetic abnormalities in PCNSL. They are considered to play a major role in the pathogenesis of PCNSL. Other genes, such as caspase recruitment domain family member 11 (CARD11), tumor necrosis factor alpha induced protein 3 (TNFAIP3), transducin (β)-like 1 X-linked receptor 1, cyclin dependent kinase inhibitor 2A, PR domain zinc finger protein 1, and proviral insertion in murine malignancies 1, are also frequently mutated. Notably, the pathogenesis of immune insufficiency-associated PCNSL is related to Epstein-Barr virus infection, and its progression may be affected by different signaling pathways. The different mutational patterns in different studies highlight the heterogeneity of PCNSL. However, existing research on the molecular genetics of PCNSL is still limited, and further research into PCNSL is required to clarify the genetic characteristics of PCNSL.

Pevonedistat, a Nedd8-activating enzyme inhibitor, in combination with ibrutinib in patients with relapsed/refractory B-cell non-Hodgkin lymphoma

Pevonedistat (TAK924) is a Nedd8-activating enzyme inhibitor with preclinical activity in non-Hodgkin lymphoma (NHL). This open-label, Phase I, multicenter, investigator-sponsored study enrolled patients with relapsed/refractory (R/R) NHL and chronic lymphocytic leukemia (CLL). The primary objective was safety. Pevonedistat was given intravenously on days 1, 3, 5 of a 21-day cycle for 8 cycles at five dose levels (15 to 50 mg/m2); ibrutinib was administered at 420 or 560 mg orally daily continuously. Eighteen patients with NHL were enrolled, including 8 patients with mantle cell lymphoma (MCL) and 4 patients with CLL. One dose-limiting toxicity (mediastinal hemorrhage) occurred at 50 mg/m2 of pevonedistat which is the estimated maximum tolerated dose. Bruising and diarrhea were the most common adverse events (56% and 44%). Atrial fibrillation occurred in 3 patients (17%). Grade ≥3 toxicities included arthralgia, atrial fibrillation, bone pain, diarrhea, hypertension, and mediastinal hemorrhage (one patient each). The overall response rate (ORR) was 65% (100% ORR in MCL). Pevonedistat disposition was not modified by ibrutinib. scRNA-Seq analysis showed that pevonedistat downregulated NFκB signaling in malignant B-cells in vivo. Thus, pevonedistat combined with ibrutinib demonstrated safety and promising early efficacy in NHL and CLL. NAE inhibition downregulated NFκB signaling in vivo.

Genetic Profiling of Diffuse Large B-Cell Lymphoma: A Comparison Between Double-Expressor Lymphoma and Non-Double-Expressor Lymphoma

INTRODUCTION

Data are limited regarding the genetic profiling of diffuse large B-cell lymphoma (DLBCL) with double expression of MYC and BCL2 proteins without underlying rearrangements (double-expressor lymphoma [DEL]). This study aimed to describe the genetic profiling and determine the prognostic significance in patients with DEL and in those with non-DEL.

METHODS

Capture-based targeted sequencing was performed on 244 patients with de novo DLBCL, not otherwise specified. Immunohistochemistry staining was performed for evaluating the MYC and BCL2 expression.

RESULTS

Among 244 patients, 46 patients had DEL, and 198 had non-DEL. KMT2D, CD58, EP300, PRDM1, TNFAIP3 and BCL2 gain or amplification (BCL2^GA/AMP) were significantly more frequently altered in the DEL group. Alterations in the BCR/TLR (p = 0.021), B-cell development and differentiation (p = 0.004), and NF-κB (p = 0.034) pathways occurred more frequently in patients with DEL. Thirty-seven DEL patients and 132 non-DEL patients were included for survival analyses. DEL was not significantly associated with progression-free survival (PFS) (p = 0.60) and overall survival (OS) (p = 0.49). In DEL patients, after adjusting for the International Prognostic Index, BCL2 alteration (HR 2.516, 95% CI 1.027-6.161; p = 0.044) remained an independent predictor of inferior PFS. BCL2^GA/AMP also predicted poor PFS, but with marginal statistical significance (HR 2.489, 95% CI 0.995-6.224; p = 0.051).

CONCLUSION

There was difference in profiling of altered genes and signaling pathways between the DEL group and the non-DEL group. The presence of DEL alone should not be considered as an adverse prognostic indicator, and BCL2 alteration could define a subset of patients with poor prognosis within DEL.

Combining precision oncology and immunotherapy by targeting the MALT1 protease

An innovative strategy for cancer therapy is to combine the inhibition of cancer cell-intrinsic oncogenic signaling with cancer cell-extrinsic immunological activation of the tumor microenvironment (TME). In general, such approaches will focus on two or more distinct molecular targets in the malignant cells and in cells of the surrounding TME. In contrast, the protease Mucosa-associated lymphoid tissue protein 1 (MALT1) represents a candidate to enable such a dual approach by engaging only a single target. Originally identified and now in clinical trials as a lymphoma drug target based on its role in the survival and proliferation of malignant lymphomas addicted to chronic B cell receptor signaling, MALT1 proteolytic activity has recently gained additional attention through reports describing its tumor-promoting roles in several types of non-hematological solid cancer, such as breast cancer and glioblastoma. Besides cancer cells, regulatory T (Treg) cells in the TME are particularly dependent on MALT1 to sustain their immune-suppressive functions, and MALT1 inhibition can selectively reprogram tumor-infiltrating Treg cells into Foxp3-expressing proinflammatory antitumor effector cells. Thereby, MALT1 inhibition induces local inflammation in the TME and synergizes with anti-PD-1 checkpoint blockade to induce antitumor immunity and facilitate tumor control or rejection. This new concept of boosting tumor immunotherapy in solid cancer by MALT1 precision targeting in the TME has now entered clinical evaluation. The dual effects of MALT1 inhibitors on cancer cells and immune cells therefore offer a unique opportunity for combining precision oncology and immunotherapy to simultaneously impair cancer cell growth and neutralize immunosuppression in the TME. Further, MALT1 targeting may provide a proof of concept that modulation of Treg cell function in the TME represents a feasible strategy to augment the efficacy of cancer immunotherapy. Here, we review the role of MALT1 protease in physiological and oncogenic signaling, summarize the landscape of tumor indications for which MALT1 is emerging as a therapeutic target, and consider strategies to increase the chances for safe and successful use of MALT1 inhibitors in cancer therapy.

Helicobacter pylori cagA status and gastric mucosa-associated lymphoid tissue lymphoma: a systematic review and meta-analysis

Background

Recent studies have investigated the role of Helicobacter pylori infection in the development of gastric mucosa-associated lymphoid tissue (MALT) lymphoma. It is estimated that approximately 0.1% of people infected with H. pylori develop gastric MALT lymphoma. However, the role of the CagA antigen, the highest causative agent of H. pylori, in increasing the risk of gastric MALT lymphoma remains unclear and controversial. A systematic review and meta-analysis were conducted to evaluate the effect of cagA status on the development of gastric MALT lymphoma.

Methods

All articles evaluating the status of the cagA gene in the development of gastric MALT lymphoma were collected using systematic searches in online databases, including PubMed, Scopus, Embase, and Google Scholar, regardless of publication date. The association between cagA and gastric MALT lymphoma was assessed using the odds ratio (OR) summary. In addition, a random-effects model was used in cases with significant heterogeneity.

Results

A total of 10 studies met our inclusion criteria, among which 1860 patients participated. No association between cagA status and the development of MALT lymphoma (extranodal marginal zone B-cell lymphoma) was found in this study (OR 1.30; 0.906–1.866 with 95% CIs; I²: 45.83; Q-value: 12.92). Surprisingly, a meaningful association was observed between cagA status and diffuse large B-cell lymphoma (OR 6.43; 2.45–16.84 with 95% CIs). We also observed an inverse association between vacA and gastric MALT lymphoma risk (OR 0.92; 0.57–1.50 with 95% CIs).

Conclusions

It seems that the infection with cagA-positive H. pylori strains does not have a meaningful effect on the gastric MALT lymphoma formation, while translocated CagA antigen into the B cells plays a crucial role in the development of diffuse large B-cell lymphoma.

B Lineage Cells in ANCA-Associated Vasculitis

Anti-neutrophil cytoplasmic antibody (ANCA)-associated vasculitis (AAV) is a systemic autoimmune disease that affects small sized blood vessels and can lead to serious complications in the lungs and kidneys. The prominent presence of ANCA autoantibodies in this disease implicates B cells in its pathogenesis, as these are the precursors of the ANCA-producing plasma cells (PCs). Further evidence supporting the potential role of B lineage cells in vasculitis are the increased B cell cytokine levels and the dysregulated B cell populations in patients. Confirmation of the contribution of B cells to pathology arose from the beneficial effect of anti-CD20 therapy (i.e., rituximab) in AAV patients. These anti-CD20 antibodies deplete circulating B cells, which results in amelioration of disease. However, not all patients respond completely, and this treatment does not target PCs, which can maintain ANCA production. Hence, it is important to develop more specific therapies for AAV patients. Intracellular signalling pathways may be potential therapeutic targets as they can show (disease-specific) alterations in certain B lineage cells, including pathogenic B cells, and contribute to differentiation and survival of PCs. Preliminary data on the inhibition of certain signalling molecules downstream of receptors specific for B lineage cells show promising therapeutic effects. In this narrative review, B cell specific receptors and their downstream signalling molecules that may contribute to pathology in AAV are discussed, including the potential to therapeutically target these pathways.

NF-κB signaling in inflammation and cancer

Since nuclear factor of κ-light chain of enhancer-activated B cells (NF-κB) was discovered in 1986, extraordinary efforts have been made to understand the function and regulating mechanism of NF-κB for 35 years, which lead to significant progress. Meanwhile, the molecular mechanisms regulating NF-κB activation have also been illuminated, the cascades of signaling events leading to NF-κB activity and key components of the NF-κB pathway are also identified. It has been suggested NF-κB plays an important role in human diseases, especially inflammation-related diseases. These studies make the NF-κB an attractive target for disease treatment. This review aims to summarize the knowledge of the family members of NF-κB, as well as the basic mechanisms of NF-κB signaling pathway activation. We will also review the effects of dysregulated NF-κB on inflammation, tumorigenesis, and tumor microenvironment. The progression of the translational study and drug development targeting NF-κB for inflammatory diseases and cancer treatment and the potential obstacles will be discussed. Further investigations on the precise functions of NF-κB in the physiological and pathological settings and underlying mechanisms are in the urgent need to develop drugs targeting NF-κB for inflammatory diseases and cancer treatment, with minimal side effects.

NF-κB and Human Cancer: What Have We Learned over the Past 35 Years?

Transcription factor NF-κB has been extensively studied for its varied roles in cancer development since its initial characterization as a potent retroviral oncogene. It is now clear that NF-κB also plays a major role in a large variety of human cancers, including especially ones of immune cell origin. NF-κB is generally constitutively or aberrantly activated in human cancers where it is involved. These activations can occur due to mutations in the NF-κB transcription factors themselves, in upstream regulators of NF-κB, or in pathways that impact NF-κB. In addition, NF-κB can be activated by tumor-assisting processes such as inflammation, stromal effects, and genetic or epigenetic changes in chromatin. Aberrant NF-κB activity can affect many tumor-associated processes, including cell survival, cell cycle progression, inflammation, metastasis, angiogenesis, and regulatory T cell function. As such, inhibition of NF-κB has often been investigated as an anticancer strategy. Nevertheless, with a few exceptions, NF-κB inhibition has had limited success in human cancer treatment. This review covers general themes that have emerged regarding the biological roles and mechanisms by which NF-κB contributes to human cancers and new thoughts on how NF-κB may be targeted for cancer prognosis or therapy.

Amplification of DDR2 mediates sorafenib resistance through NF-κB/c-Rel signaling in hepatocellular carcinoma

Sorafenib was the first systemic therapy approved by the Food and Drug Administration to treat advanced hepatocellular carcinoma (HCC). However, sorafenib therapy is frequently accompanied by drug resistance. We aimed to explore the mechanisms of sorafenib resistance and provide feasible solutions to increase the response to sorafenib in patients with advanced HCC. The expression profile of discoidin domain receptor 2 (DDR2) in HCC tissues and cells was detected using quantitative real-time PCR (qPCR) and western blotting assays. The effects of DDR2 on sorafenib resistance were examined using 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide, colony formation, TdT-mediated dUTP nick end labeling, and flow cytometry assays. The effect of DDR2 on the nuclear factor kappa B (NF-κB) signaling pathway was evaluated by luciferase reporter, immunofluorescence, qPCR and flow cytometry assays. We demonstrated that DDR2 expression was dramatically upregulated in sorafenib-resistant HCC tissues relative to sensitive tissues. Downregulation of DDR2 sensitized HCC cell lines to sorafenib cytotoxicity. Further analysis showed that DDR2 could increase the nuclear location of REL proto-oncogene, a NF-κB subunit, to mediate NF-κB signaling. Blocking NF-κB signaling using the NF-κB signaling inhibitor, bardoxolone methyl, increased the response of HCC cells to sorafenib. Further analysis showed that DNA amplification of DDR2 is an important mechanism leading to DDR2 overexpression in HCC. Our results demonstrated that DDR2 is a potential therapeutic target in patients with HCC, and targeting DDR2 represents a promising approach to increase sorafenib sensitivity in patients with HCC.

The clinicopathological and molecular features of sinusoidal large B-cell lymphoma

We report 17 cases of sinusoidal large B-cell lymphoma (SLBCL). Clinical, morphologic, immunophenotypic, and molecular features were detected and analyzed. All cases showed an obvious sinusoidal growth pattern, usually associated with residual atrophic lymphoid tissue. All tumors contained large pleomorphic lymphoid cells and one or more prominent nucleoli, with abundant amphophilic cytoplasms; 15/17 cases showed anaplastic morphologic features. The patient age ranged from 43 to 80 years (median 57 years), and 7 males and 10 females were included. Eleven of 15 (73.3%) patients had Ann Arbor stage III or IV disease, and 10/15 (66.6%) patients had an International Prognostic Index (IPI) score ≥3. Immunophenotypically, 16/17 (94.1%) cases displayed a nongerminal center B-cell (non-GCB) immunophenotype. Furthermore, 16/17 (94.1%) cases were positive for CD30, and p53 was expressed in 10/16 (62.5%) cases. In total, 12/14 (85.7%) cases expressed BCL2 and MYC simultaneously (double expression), and 11/14 (78.6%) cases showed PD-L1 positivity (6/11 had a PD-L1 tumor proportion score ≥50%). Cytogenetically, concurrent MYC and BCL2 and/or BCL6 abnormalities (break-apart or extra copy) were detected in 10/15 cases, and 7/13 (53.8%) cases harbored a PD-L1/L2 amplification. TP53 mutation was found in 7/13 (53.8%) cases by Sanger sequencing. Whole-exome and large-panel sequencing results revealed high mutation frequencies of TP53 (4/7), MYD88 (3/7), KMT2D (3/7), CREBBP (3/7), and PIM1 (3/7). Among the 13 patients with SLBCL treated with aggressive chemotherapy regimens, the median overall survival (OS) was 18 months, and the 2-year OS rate was 34.6%. The OS of patients with SLBCL was markedly worse than that of 35 control group patients with common diffuse large B-cell lymphoma (DLBCL) without sinusoidal features (P < 0.001). SLBCL may represent a specific type of DLBCL that has characteristic pathologic features. The cancer is aggressive in most clinical cases, and outcomes are poor. SLBCL and anaplastic DLBCL (A-DLBCL) have many overlapping clinicopathological and molecular features.

Mutational Profile and Clonal Evolution of Relapsed/Refractory Diffuse Large B-Cell Lymphoma

Primary refractory/relapsed diffuse large B-cell lymphoma (rrDLBCL) is an unresolved issue for DLBCL treatment and new treatments to overcome resistance is required. To explore the genetic mechanisms underlying treatment resistance in rrDLBCL and to identify candidate genes, we performed targeted deep sequencing of 430 lymphoma-related genes from 58 patients diagnosed with rrDLBCL. Genetic alterations found between the initial biopsy and biopsy at recurrence or refractory disease were investigated. The genes most frequently altered (> 20%) were (in decreasing order of frequency) CDKN2A, PIM1, CD79B, TP53, MYD88, MYC, BTG2, BTG1, CDKN2B, DTX1, CD58, ETV6, and IRF4. Genes mutation of which in pretreatment sample were associated with poor overall survival included NOTCH1, FGFR2, BCL7A, BCL10, SPEN and TP53 (P < 0.05). FGFR2, BCL2, BCL6, BCL10, and TP53 were associated with poor progression-free survival (P < 0.05). Most mutations were truncal and were maintained in both the initial biopsy and post-treatment biopsy with high dynamics of subclones. Immune-evasion genes showed increased overall mutation frequency (CD58, B2M) and variant allele fraction (CD58), and decreased copy number (B2M, CD70) at the post-treatment biopsy. Using the established mutational profiles and integrative analysis of mutational evolution, we identified information about candidate genes that may be useful for the development of future treatment strategies.

Significance of abnormal 53BP1 expression as a novel molecular pathologic parameter of follicular-shaped B-cell lymphoid lesions in human digestive tract

The digestive tract is a common site of extranodal malignant lymphomas (MLs) and benign lymphoid lesions (BLs). TP53-binding protein 1 (53BP1) expression has been widely investigated in class switch recombination but rarely in human lymphoid tissues with respect to tumorigenesis. We previously reported that immunofluorescence (IF) analysis of 53BP1 nuclear foci (NF), reflecting DNA double strand breaks, is useful for estimating genomic instability in different tumor types. In this study, we evaluated the potential of IF-based analysis of 53BP1 expression in differentiating MLs from BLs. We examined 231 biopsied tissue samples of primary MLs and BLs in the digestive tract. The 53BP1 immunoreactivity pattern was determined by multicolor IF. Compared to BLs, MLs showed a high frequency of abnormal 53BP1 expression (p < 0.0001). Statistically, abnormal 53BP1 expression is an effective test for distinguishing follicular lymphomas from BLs (specificity 98.6%, sensitivity 86.8%) and for distinguishing small B-cell lymphomas from BLs (specificity 98.3%, sensitivity 77.6%). Furthermore, a high frequency of abnormal 53BP1 expression was associated with “high-risk” MALT lymphomas, which exhibited t(11;18)(q21;21) (p = 0.0145). Collectively, these results suggest that IF-based analysis of 53BP1 expression in biopsy samples is a promising technique for diagnosing MLs in the digestive system.

MYD88 L265P mutation in primary central nervous system lymphoma is associated with better survival: A single-center experience

BACKGROUND

The myeloid differentiation primary response gene (MYD88) mutation in primary central nervous system lymphomas (PCNSL) may be associated with unfavorable prognosis; however, current evidence remains limited. We aimed to characterize PCNSLs by integration of clinicopathological, molecular, treatment, and survival data.

METHODS

We retrospectively identified and validated 57 consecutive patients with PCNSLs according to the 2017 WHO classification of lymphoid neoplasms over 13 years. Formalin-fixed paraffin-embedded tumor samples underwent polymerase chain reaction assay to detect MYD88 mutation. We used Cox regression for survival analysis, including age, treatment, and MYD88 as covariates. We searched the literature for studies reporting demographics, treatment, MYD88, and survival of PCNSL patients and incorporated individual patient data into our analyses.

RESULTS

The median age was 66 years and 56% were women. All 57 patients had PCNSL of non-germinal center cell subtype and the majority (81%) received either single or combined therapies. There were 46 deaths observed over the median follow-up of 10 months. MYD88 mutation status was available in 41 patients of which 36 (88%) were mutated. There was an association between MYD88 mutation and better survival in the multivariable model (hazard ratio [HR] 0.277; 95% confidence interval [CI]: 0.09-0.83; P = .023) but not in a univariable model. After incorporating additional 18 patients from the literature, this association was reproducible (HR 0.245; 95% CI: 0.09-0.64; P = .004).

CONCLUSIONS

Adjusting for confounders, MYD88-mutant PCNSL appears to show improved survival. While further validation is warranted, detection of MYD88 mutation will aid the identification of patients who may benefit from novel targeted therapies.

FYN-TRAF3IP2 induces NF-κB signaling-driven peripheral T cell lymphoma

Angioimmunoblastic T cell lymphoma (AITL) and peripheral T cell lymphoma not-otherwise-specified (PTCL, NOS) have poor prognosis and lack driver actionable targets for directed therapies in most cases. Here we identify FYN-TRAF3IP2 as a recurrent oncogenic gene fusion in AITL and PTCL, NOS tumors. Mechanistically, we show that FYN-TRAF3IP2 leads to aberrant NF-κB signaling downstream of T cell receptor activation. Consistent with a driver oncogenic role, FYN-TRAF3IP2 expression in hematopoietic progenitors induces NF-κB-driven T cell transformation in mice and cooperates with loss of the Tet2 tumor suppressor in PTCL development. Moreover, abrogation of NF-κB signaling in FYN-TRAF3IP2-induced tumors with IκB kinase inhibitors delivers strong anti-lymphoma effects in vitro and in vivo. These results demonstrate an oncogenic and pharmacologically targetable role for FYN-TRAF3IP2 in PTCLs and call for the clinical testing of anti-NF-κB targeted therapies in these diseases.

Targeting pathogenic mechanisms in marginal zone lymphoma: from concepts and beyond

Marginal zone lymphoma (MZL) represents a group of three distinct though overlapping lymphoid malignancies that includes extranodal, nodal and splenic marginal lymphoma. MZL patients usually present an indolent clinical course, although the disease remains largely incurable, save early stage disease that might be irradiated. Therapeutic advances have been limited due to the small patient population, and have largely been adapted from other indolent lymphomas. Here, we discuss the numerous targets and pathways which may offer the prospect of directly inhibiting the mechanisms identified promoting and sustaining marginal zone lymphomagenesis. In particular, we focus on the agents that may have at least a theoretical application in the disease. Various dysregulated pathways converge to produce an overarching stimulation of nuclear factor κB (NF-κB) and the MYD88-IRAK4 axis, which can be thus leveraged or targeting B-cell receptor signaling through BTK inhibitors (such as ibrutinib, zanubrutinib, acalabrutinib) and PI3K inhibitors (such as idelalisib, copanlisib, duvelisib umbralisib) or via more novel agents in development such as MALT1 inhibitors, SMAC mimetics, NIK inhibitors, IRAK4 or MYD88 inhibitors. NOTCH signaling is also crucial for marginal zone cells, but no clinical data are available with NOTCH inhibitors such as the γ-secretase inhibitor PF-03084014 or the NICD inhibitor CB-103. The hypermethylation phenotype, the overexpression of the PRC2-complex or the presence of TET2 mutations reported in MZL subsets make epigenetic agents (demethylating agents, EZH2 inhibitors, HDAC inhibitors) also potential therapeutic tools for MZL patients.

Overexpression of microRNA-130a predicts adverse prognosis of primary gastrointestinal diffuse large B-cell lymphoma

Primary gastrointestinal diffuse large B-cell lymphoma (PGI-DLBCL) is a highly heterogeneous type of non-Hodgkin lymphoma. A number of studies have demonstrated that microRNA-130a (miR-130a) serves a role in the tumorigenesis and prognosis of numerous human tumors. However, to the best of our knowledge, the prognostic significance of miR-130a in PGI-DLBCL remains unknown. The present study explored the association between miR-130a and the clinical outcomes of PGI-DLBCL. Relative miR-130a expression was assessed by reverse transcription-quantitative PCR. Immunohistochemistry was used to detect expression levels of BCL-2, c-MYC, neprilysin, B-cell lymphoma 6 protein, PWWP domain-containing DNA repair factor 3A and proliferation marker protein Ki-67. A receiver operating characteristic curve was constructed to analyze the specificity and sensitivity of microRNA levels in the diagnosis of PGI-DLBCL. Survival curves were constructed using the Kaplan-Meier method. In the present study, miR-130a expression was notably higher in patients with PGI-DLBCL compared with in the controls (P<0.0001). miR-130a overexpression was closely associated with a high International Prognostic Index score (3–5) and drug resistance (P=0.017 and P=0.044, respectively). No significant difference in other clinical features was observed. Patients with increased expression levels of miR-130a had lower overall survival [hazard ratio (HR), 2.998; 95% CI, 1.347-6.673; P=0.007] and progression-free survival (HR, 3.325; 95% CI, 1.488-7.429; P=0.003) compared with patients who had lower expression levels of miR-130a. Furthermore, multivariate Cox regression analysis suggested that miR-130a was a negative prognostic parameter in PGI-DLBCL. Therefore, upregulation of miR-130a could become a potential prognostic marker for PGI-DLBCL. Additionally, further study of these results may have important guiding significance for the prognosis of patients with PGI-DLBCL in the clinical setting.

PD-L1 (SP142) expression in neoplastic cells predicts a poor prognosis for patients with intravascular large B-cell lymphoma treated with rituximab-based multi-agent chemotherapy

Background

Intravascular large B‐cell lymphoma (IVLBCL) is a rare form of diffuse large B‐cell lymphoma (DLBCL) arising in extranodal sites. PD‐L1 expression of tumor cells has been reported in IVLBCL cells, but its clinicopathological relevance remains to be elucidated.

Aims

This study was aimed to reveal the characteristics of PD‐L1⁺ IVLBCL.

Methods and results

Neoplastic PD‐L1 expression was examined in 34 cases of IVLBCL and clinicopathological characteristics between patients with PD‐L1⁺ and PD‐L1⁻ IVLBCL were compared. We assessed PD‐L1 expression with SP142 antibody. Twelve (35%) of 34 cases showed positivity for PD‐L1. The PD‐L1⁺ group had significantly lower survival rates compared to the PD‐L1⁻ group. The PD‐L1⁺ IVLBCL group also had a significantly lower age distribution and a lower frequency of patients older than 60 years compared to the PD‐L1⁻ group. Very recently, we speculate that there is possible link between PD‐L1⁺ IVLBCL and PD‐L1⁺ extranodal DLBCL‐NOS (eDLBCL) because features of the two groups showed overlapping. Therefore, we compared the clinicopathological characteristics of the PD‐L1⁺ IVLBCL and PD‐L1⁺ eDLBCL. There were no significant differences in clinicopathological parameters and prognosis.

Conclusion

The worse prognosis of the PD‐L1⁺ group might be caused by immune evasion mechanisms, which are linked to PD‐L1 expression. Therefore, PD‐L1⁺ IVLBCL cases might be regarded as good candidates for targeted immunotherapy. We also highlighted the overlapping features of PD‐L1⁺ IVLBCL and PD‐L1⁺ eDLBCL. This result suggests that they should be regarded as one entity, immune evasion‐related extranodal large B‐cell lymphoma.

New biomarkers in non-Hodgkin lymphoma and acute leukemias

Biomarkers play a critical role in the medical care of patients with cancer, including in early detection of the disease, diagnostic accuracy, risk stratification, treatment, and follow-up. Biomarkers in hematological malignancies can support the redefinition of the diagnosis and adjustments in the treatment plan. Biomarkers can be classified into 4 categories: (1) protein antigens, (2) cytogenetic abnormalities, (3) genetic polymorphisms, and (4) gene expression. Efforts in genomics, proteomics, and metabolomics to observe new biomarkers that contribute to the development of clinical medicine with greater precision in the strategies that improve prevention, diagnosis, and treatment of patients with malignant hematological disease. New biomarkers should accomplish several issues such as the biological plausibility, methodology used, analytical validation, intellectual property registry, and legal framework of application. This knowledge should be transferred to health professionals who can carry out the process of its implementation in clinical practice.

Synergistic Effect of 1,3,6-Trihydroxy-4,5,7-Trichloroxanthone in Combination with Doxorubicin on B-Cell Lymphoma Cells and Its Mechanism of Action Through Molecular Docking

Background

The increasing rate of cancer chemoresistance and adverse side effects of therapy have led to the wide use of various chemotherapeutic combinations in cancer management, including lymphoid malignancy.

Objective

We investigated the effects of a combination of 1,3,6-trihydroxy-4,5,7-trichloroxanthone (TTX) and doxorubicin on the Raji lymphoma cell line.

Methods

Raji cells were treated with different concentrations of TTX, doxorubicin, or combinations thereof. Cancer cell growth inhibition was evaluated using 3-(4,5-dimethyltiazol-2-yl)-2,5- diphenyltetrazolium bromide/MTT assay to determine the half-maximal inhibitory concentration. Combination index values were calculated using CompuSyn (ComboSyn, Inc, Paramus, NJ). Molecular docking was conducted using a Protein-Ligand ANT System.

Results

The mean (SD) half-maximal inhibitory concentration values of TTX and doxorubicin were 15.948 (3.101) µM and 25.432 (1.417) µM, respectively. The combination index values of the different combinations ranged from 0.057 to 0.285, indicating strong to very strong synergistic effects. The docking study results reveal that TTX docks at the active site of Raf-1 and c-Jun N-kinase receptors with predicted free energies of binding of -79.37 and -75.42 kcal/mol, respectively.

Conclusions

The xanthone-doxorubicin combination showed promising in vitro activity against lymphoma cells. The results also indicate that the TTX and doxorubicin combination's effect was due to the interaction between TTX with Raf-1 and c-Jun N-kinase receptors, 2 determinants of doxorubicin resistance progression.

Prevalence And Clinical Significance Of Oncogenic CD79B And MYD88 Mutations In Primary Testicular Diffuse Large B-Cell Lymphoma: A Retrospective Study In China

Purpose

In this study, we investigated the prevalence of CD79B and MYD88 mutations and their relation to clinical characteristics in a cohort of Chinese patients with primary testicular diffuse large B cell lymphoma (PT-DLBCL).

Patients and methods

We examined the mutational status of CD79B and MYD88 by Sanger sequencing, and the gene amplification and protein expression of MYD88 in tissue samples from 30 cases of PT-DLBCL by quantitative polymerase chain reaction and immunohistochemistry, respectively. Western blotting was used to analyze phosphorylated STAT3 (p-STAT3) and phosphorylated p65 (p-p65) protein expression in cell lines harboring retroviral constructs for WT MYD88 or MYD88 mutant.

Results

Immunophenotypically, MYD88 protein staining was positive in 26/30 (86.67%) cases, and 23/30 (76.7%) cases tested positive for p65 in the nucleus. Genetically, CD79B mutation was found in 13/30 (43.3%) cases, whereas the MYD88^L265P mutation was found in 18/30 (60.0%) cases. Interestingly, CD79B and MYD88 mutations were more prevalent in the non-germinal center B cell (GCB) subtype (83.3% and 76.9%, respectively) and were relatively rare in the GCB subtype (16.7% and 23.1%, respectively). Furthermore, although MYD88 was significantly amplified in PT-DLBCL, the amplification status showed no correlation with its mutational status and protein expression. Clinicopathological comparison between the mutant and wild-type group showed that both CD79B mutation and MYD88^L265P were not significantly correlated with age, anatomical site, Ann Arbor stage, non-GCB/GCB subtype, p65 protein expression, BCL-2 protein expression, or BCL-2/c-MYC double expression (P>0.05). Survival analyses showed that high IPI and advanced stage (stage III–IV) associated with worse outcome (P<0.05). The expression of p-STAT3 and p-p65 protein was upregulated in the mutant group, indicating that MYD88 mutant activated NF-κB and JAK–STAT3 signaling.

Conclusion

Our results suggest that MYD88 and CD79B mutations are important drivers of immune-privileged site-associated DLBCL and highlight potential therapeutic targets for personalized treatment.

Activation of the NF-κB Pathway and Heterozygous Deletion of TNFAIP3 (A20) Confer Superior Survival in Extranodal Natural Killer/T-Cell Lymphoma, Nasal Type

OBJECTIVES

To investigate the role of TNFAIP3 deletions and NF-κB activation in extranodal natural killer/T-cell lymphoma (ENKTCL), nasal type.

METHODS

In total, 138 patients with ENKTCL were included. Activation of NF-κB pathway and expression of TNFAIP3 (A20) were examined by immunohistochemistry. TNFAIP3 was analyzed for deletions using FICTION (fluorescence immunophenotyping and interphase cytogenetics as a tool for investigating neoplasms), for mutations using Sanger sequencing, and for promoter methylation using methylation-specific sequencing.

RESULTS

NF-κB pathway activation was observed in 31.2% of cases (43/138), TNFAIP3 expression was negative in 15.2% of cases (21/138), and heterozygous TNFAIP3 deletion was observed in 35% of cases (35/100). TNFAIP3 exons 2 to 9 mutations and promoter methylation were not observed. Kaplan-Meier analysis showed patients with NF-κB pathway activation or TNFAIP3 heterozygous deletion to have a longer overall survival.

CONCLUSIONS

Our study demonstrated that NF-κB activation and TNFAIP3 heterozygous deletion confer superior survival in patients with ENKTCL.

The Unsolved Puzzle of c-Rel in B Cell Lymphoma

Aberrant constitutive activation of Rel/NF-κB transcription factors is a hallmark of numerous cancers. Of the five Rel family members, c-Rel has the strongest direct links to tumorigenesis. c-Rel is the only member that can malignantly transform lymphoid cells in vitro. Furthermore, c-Rel is implicated in human B cell lymphoma through the frequent occurrence of REL gene locus gains and amplifications. In normal physiology, high c-Rel expression predominates in the hematopoietic lineage and a diverse range of stimuli can trigger enhanced expression and activation of c-Rel. Both expression and activation of c-Rel are tightly regulated on multiple levels, indicating the necessity to keep its functions under control. In this review we meta-analyze and integrate studies reporting gene locus aberrations to provide an overview on the frequency of REL gains in human B cell lymphoma subtypes, namely follicular lymphoma, diffuse large B cell lymphoma, primary mediastinal B cell lymphoma, and classical Hodgkin lymphoma. We also summarize current knowledge on c-Rel expression and protein localization in these human B cell lymphomas and discuss the co-amplification of BCL11A with REL. In addition, we highlight and illustrate key pathways of c-Rel activation and regulation with a specific focus on B cell biology.

Rare cases of primary central nervous system anaplastic variant of diffuse large B-cell lymphoma

BACKGROUND

Primary central nervous system (CNS) diffuse large B-cell lymphoma (DLBCL) is a rare intracranial tumor, defined as DLBCL arising from the brain, spinal cord, leptomeninges and eye, with an overall annual incidence of 5 cases per million. The primary CNS anaplastic variant of DLBCL (A-DLBCL) is even less common; to our knowledge, there are only two other case reports in the literature. The aim of this report is to present rare cases of primary CNS A-DLBCL and study their clinicopathologic and genetic features.

CASE PRESENTATION

We report 3 patients, two men and one woman, aged 54, 55 and 67 years old, with primary CNS A-DLBCL. All 3 patients had a high International Extranodal Lymphoma Study Group (IELSG) score; although the patients were treated with methotrexate-based regimens and/or with radiation therapy, the overall survival was only 2, 5, and 8 months. All 3 patients presented with characteristic features of perivascular space infiltration with bizarre-shaped tumor cells, leading to the diagnosis of primary CNS A-DLBCL. Concurrent of MYC and BCL2 and/or BCL6 abnormalities and MYC/BCL2 double-expressor DLBCL occurred in all 3 patients; two patients had MYC/BCL2/BCL6 triple extra copies, and one patient had MYC extra copy and BCL6 translocation. All 3 patients displayed mutations in MYD88 L265P and nuclear positivity for RELA, RELB and/or c-Rel, indicating constitutive activation of the NF-κB pathway.

CONCLUSIONS

These cases shed light on the unique genetic alterations and biological features of primary CNS A-DLBCL. Patients with primary CNS A-DLBCL may often have a MYC/BCL2 double-expressor and concurrent MYC and BCL2 and/or BCL6 genetic abnormalities, as well as constitutive activation of the NF-κB pathway. Primary CNS A-DLBCL follows a very aggressive disease course and poor prognosis. In the future, a large number of cases should be analyzed, and the evaluation of molecular genetic characteristics could help with practical and therapeutic implications for primary CNS A-DLBCL.

IL1R8 Deficiency Drives Autoimmunity-Associated Lymphoma Development

Chronic inflammation, including that driven by autoimmunity, is associated with the development of B-cell lymphomas. IL1R8 is a regulatory receptor belonging to the IL1R family, which negatively regulates NF-κB activation following stimulation of IL1R or Toll-like receptor family members. IL1R8 deficiency is associated with the development of severe autoimmune lupus-like disease in lpr mice. We herein investigated whether concomitant exacerbated inflammation and autoimmunity caused by the deficiency of IL1R8 could recapitulate autoimmunity-associated lymphomagenesis. We thus monitored B-cell lymphoma development during the aging of IL1R8-deficient lpr mice, observing an increased lymphoid cell expansion that evolved to diffuse large B-cell lymphoma (DLBCL). Molecular and gene-expression analyses showed that the NF-κB pathway was constitutively activated in Il1r8 ^-/-/lpr B splenocytes. In human DLBCL, IL1R8 had reduced expression compared with normal B cells, and higher IL1R8 expression was associated with a better outcome. Thus, IL1R8 silencing is associated with increased lymphoproliferation and transformation in the pathogenesis of B-cell lymphomas associated with autoimmunity.

Aberrant Activation of NF-κB Signalling in Aggressive Lymphoid Malignancies

Lymphoid malignancies frequently harbor genetic mutations leading to aberrant activation of nuclear factor-κB (NF-κB) signaling; in normal cells, this pathway has important roles in the control of cell growth, survival, stress responses, and inflammation. Malignancies with mutations in NF-κB pathway components can derive from all cell stages of mature B-cell development; however, aberrant NF-κB activity is particularly prevalent in aggressive subtypes of non-Hodgkin lymphoma and myeloma. NF-κB activation is mediated by two separate pathways, the canonical and alternative pathway, and five downstream transcription factor subunits. Recent findings implicate a predominant role for distinct NF-κB pathways and subunits in certain lymphoma subtypes and myeloma; findings which are complemented by the realization that individual NF-κB subunits can have unique, non-redundant biological roles in the putative tumor precursor cells, including activated B cells, germinal center B cells and plasma cells. The knowledge gained from these studies may be exploited for the development of therapeutic strategies to inhibit aberrant NF-κB activity at the level of the transcription-factor subunits and their target genes, as global inhibition of the pathway is toxic. Here, we provide an overview on the role of aberrant NF-κB activation in aggressive lymphoid malignancies and discuss the potential importance of individual NF-κB subunits in the pathogenesis of tumor subtypes.

Prognostic impact of MYD88 mutation, proliferative index and cell origin in diffuse large B cell lymphoma

Background

Diffuse large B-cell lymphoma, among non-Hodgkin lymphomas, is one of the most frequent subtypes. Clinical laboratory data and post-treatment outcomes are scarce in the Brazilian population.

Objective

The main objective of this retrospective study was to assess the impact of tumor markers, including the Myeloid differentiation primary response 88 (MYD88) mutation.

Method

Eighty-three patients were included and treated with R-CHOP or R-CHOP-like regimens.

Results

Median age was 64-years old and 58% were female patients. The median follow-up was 42 months. The progression free survival (PFS) at this time was 63% and overall survival (OS), 66%. In the patients with tumors expressing Myc proto-oncogene protein (MYC) and B-cell lymphoma 2 (BCL2), assessed by immunohistochemistry (IHC), known as dual protein expressers, median post-progression survival was 31 (15–45) months. An increased proliferative index were associated with a high rate of progression (hazard ratio 2.31 [95% confidence interval [1.05–5.12]; p = 0.04). The cell of origin (COO), identified by IHC, was not able to predict PFS (p = 0.76). The MYD88 L265P mutation was present in 10.8% (9/83) of patients and did not show a prognostic correlation.

Conclusion

In conclusion, the MYD88 mutation, although an important tool for diagnosis and a possible target drug, presented at a low frequency and was not a prognostic marker in this population.

Characterization of genomic alterations in primary central nervous system lymphomas

PURPOSE

Primary central nervous system lymphoma (PCNSL) is a non-Hodgkin lymphoma that affects the central nervous system (CNS). Although previous studies have reported the most common mutated genes in PCNSL, including MYD88 and CD79b, our understanding of genetic characterizations in primary CNS lymphomas is limited. The aim of this study was to perform a retrospective analysis investigating the most frequent mutation types, and their frequency, in PCNSL.

METHODS

Fifteen patients with a diagnosis of PCNSL from our institution were analyzed for mutations in 406 genes and rearrangements in 31 genes by next generation sequencing (NGS).

RESULTS

Missense mutations were identified as the most common mutation type (32%) followed by frame shift mutations (23%). The highest mutation rate was reported in the MYD88 (33.3%), CDKN2A/B (33.3%), and TP53 (26.7%) genes. Intermediate tumor mutation burden (TMB) and high TMB was detected in 13.3% and 26.7% of PCNSL, respectively. The most frequent gene rearrangement involved the IGH-BCL6 genes (20%).

CONCLUSIONS

This study shows the most common genetic alterations in PCNSL as determined by a commercial next generation sequencing assay. MYD88 and CD79b are frequently mutated in PCNSL, IGH-BCL6 is the most frequent gene rearrangement and approximately 1/4 of cases show a high TMB. Mutations in multiple genes, in addition to high TMB and gene rearrangements, highlights the complex molecular heterogeneity of PCNSL. Knowledge about genetic alterations in PCNSL can inform the development of novel targets for diagnosis and treatment.

Molecular analysis in liquid biopsies for diagnostics of primary central nervous system lymphoma: Review of literature and future opportunities

Primary central nervous system lymphoma (PCNSL) is an aggressive lymphoma with a poor prognosis, for which accurate and timely diagnosis is of utmost importance. Unfortunately, diagnosis of PCNSL can be challenging and a brain biopsy (gold standard for diagnosis) is an invasive procedure with the risk of major complications. Thus, there is an urgent need for an alternative strategy to diagnose and monitor these lymphomas. Currently, liquid biopsies from cerebrospinal fluid (CSF) are used for cytomorphologic and flow cytometric analysis. Recently, new biomarkers such as genetic mutations and interleukins have been identified in these liquid biopsies, further expanding the diagnostic armamentarium. In this review we present an overview of genetic aberrations (>70) reported in this unique lymphoma. Of these genes, we have selected those that are reported in ≥3 studies. Half of the selected genes are implicated in the NFκB pathway (CARD11, CD79B, MYD88, TBL1XR1 and TNFAIP3), while the other half are not related to this pathway (CDKN2A, ETV6, PIM1, PRDM1 and TOX). Although this underlines the crucial role of the NFκB pathway in PCNSL, CD79B and MYD88 are at present the only genes mentioned in liquid biopsy analysis. Finally, a stepwise approach is proposed for minimally invasive liquid biopsy analysis and work-up of PCNSL, incorporating molecular analysis. Prioritization and refinements of this approach can be constructed based upon multidisciplinary collaboration as well as novel scientific insights.

Analysis of NFKB2‑mediated regulation of mechanisms underlying the development of Hodgkin's lymphoma

Nuclear factor-κB (NF-κB) is widely involved in various lymphoid malignancies. However, its exact functional role and potential regulatory mechanisms in Hodgkin's lymphoma (HL) remains unclear. The present study aimed to investigate the regulatory mechanism of NF-κB in HL by analysis of a gene expression profile that was obtained from HL cells with or without NF-κB subunit 2 (NFKB2) knockdown. The GSE64234 dataset containing 6 HL cell line specimens transfected with small interfering (si)RNA against NFKB2 and 6 control specimens transfected with non-targeting siRNA sequences was downloaded from the Gene Expression Omnibus database. Based on these data, differentially expressed genes (DEGs) were screened for following data preprocessing. Functional enrichment analysis was subsequently conducted among the identified upregulated and downregulated DEGs. Additionally, a protein-protein interaction (PPI) network was constructed and module analyses were performed. Finally, microRNAs (miRNAs/miRs) targeting the identified DEGs were predicted for the construction of a miRNA-target regulatory network. A total of 253 DEGs were identified, consisting of 109 upregulated and 144 downregulated DEGs. Pathway enrichment analysis revealed that B-cell lymphoma 2-like 1 (BCL2L1) was significantly enriched in the NF-κB signaling pathway, and colony-stimulating factor 2 (CSF2) and BCL2L1 were enriched in the Jak-signal transducer and activator of transcription (STAT) signaling pathway. BCL2L1 and CSF2 were determined to be hub genes in the PPI network. A total of 6 miRNAs, including let-7a-5p, miR-9-5p, miR-155-5p, miR-135a-5p, miR-17-5p and miR-375, were identified in the miRNA-target regulatory network. The results of the present study indicated that NFKB2 may be involved in HL development through regulation of BCL2L1, CSF2, miR-135a-5p, miR-155-5p and miR-9-5p expression, as well as the modulation of Jak-STAT and NF-κB signaling pathways.

NF-κB Activation in Lymphoid Malignancies: Genetics, Signaling, and Targeted Therapy

The NF-κB transcription factor family plays a crucial role in lymphocyte proliferation and survival. Consequently, aberrant NF-κB activation has been described in a variety of lymphoid malignancies, including diffuse large B-cell lymphoma, Hodgkin lymphoma, and adult T-cell leukemia. Several factors, such as persistent infections (e.g., with Helicobacter pylori), the pro-inflammatory microenvironment of the cancer, self-reactive immune receptors as well as genetic lesions altering the function of key signaling effectors, contribute to constitutive NF-κB activity in these malignancies. In this review, we will discuss the molecular consequences of recurrent genetic lesions affecting key regulators of NF-κB signaling. We will particularly focus on the oncogenic mechanisms by which these alterations drive deregulated NF-κB activity and thus promote the growth and survival of the malignant cells. As the concept of a targeted therapy based on the mutational status of the malignancy has been supported by several recent preclinical and clinical studies, further insight in the function of NF-κB modulators and in the molecular mechanisms governing aberrant NF-κB activation observed in lymphoid malignancies might lead to the development of additional treatment strategies and thus improve lymphoma therapy.

IKK/NF-κB signaling contributes to glioblastoma stem cell maintenance

Glioblastoma multiforme (GBM) carries a poor prognosis and continues to lack effective treatments. Glioblastoma stem cells (GSCs) drive tumor formation, invasion, and drug resistance and, as such, are the focus of studies to identify new therapies for disease control. Here, we identify the involvement of IKK and NF-κB signaling in the maintenance of GSCs. Inhibition of this pathway impairs self-renewal as analyzed in tumorsphere formation and GBM expansion as analyzed in brain slice culture. Interestingly, both the canonical and non-canonical branches of the NF-κB pathway are shown to contribute to this phenotype. One source of NF-κB activation in GBM involves the TGF-β/TAK1 signaling axis. Together, our results demonstrate a role for the NF-κB pathway in GSCs and provide a mechanistic basis for its potential as a therapeutic target in glioblastoma.

Impaired Control of Epstein-Barr Virus Infection in B-Cell Expansion with NF-κB and T-Cell Anergy Disease

B-cell expansion with NF-κB and T-cell anergy (BENTA) disease is a B-cell-specific lymphoproliferative disorder caused by germline gain-of-function mutations in CARD11. These mutations force the CARD11 scaffold into an open conformation capable of stimulating constitutive NF-κB activation in lymphocytes, without requiring antigen receptor engagement. Many BENTA patients also suffer from recurrent infections, with 7 out of 16 patients exhibiting chronic, low-grade Epstein–Barr virus (EBV) viremia. In this mini-review, we discuss EBV infection in the pathogenesis and clinical management of BENTA disease, and speculate on mechanisms that could explain inadequate control of viral infection in BENTA patients.

The Role of the Transcription Factor Nuclear Factor-kappa B in Thyroid Autoimmunity and Cancer

Nuclear factor-kappa B (NF-κB) is a ubiquitous transcription factor that is involved in inflammatory and immune responses, as well as in regulation of expression of many other genes related to cell survival, proliferation, and differentiation. In mammals, NF-κB comprises five subunits that can bind to promoter regions of target genes as homodimers or heterodimers. The most common dimer is the p50/p65 heterodimer. The several combinations of dimers that can be formed contribute to the heterogeneous regulation of NF-κB target genes, and this heterogeneity is further increased by interactions of the NF-κB dimers with other transcription factors, such as steroid hormone receptors, activator protein-1 (AP-1), and cAMP response element binding protein (CREB). In the thyroid, several studies have demonstrated the involvement of NF-κB in thyroid autoimmunity, thyroid cancer, and thyroid-specific gene regulation. The role of NF-κB in thyroid autoimmunity was hypothesized more than 20 years ago, after the finding that the binding of distinct NF-κB heterodimers to the major histocompatibility complex class I gene is hormonally regulated. Further studies have shown increased activity of NF-κB in thyroid autoimmune diseases and in thyroid orbitopathy. Increased activity of NF-κB has also been observed in thyroid cancer, where it correlates with a more aggressive pattern. Of particular interest, mutation of some oncogenes or tumor suppressor genes involved in thyroid carcinogenesis results in constitutive activation of the NF-κB pathway. More recently, it has been shown that NF-κB also has a role in thyroid physiology, as it is fundamental for the expression of the main thyroid-specific genes, such as sodium iodide symporter, thyroid peroxidase, thyroglobulin, Pax8, and TTF-1 (NKX2-1).

High frequency and prognostic value of MYD88 L265P mutation in diffuse large B-cell lymphoma with R-CHOP treatment

The aim of this study was to analyze the prevalence and prognostic value of myeloid differentiation factor 88 (MYD88) L265P in diffuse large B-cell lymphoma (DLBCL) patients treated with rituximab plus cyclophosphamide, doxorubicin, vincristine, and prednisone (R-CHOP). We assessed the MYD88 L265P mutation using an allele-specific semi-nested polymerase chain reaction method in 53 DLBCL patients treated with R-CHOP. The MYD88 L265P mutation was detected in 16 of 53 DLBCL (30.19%) samples from patients treated with R-CHOP. Age and location were statistically significantly associated with MYD88 L265P (P=0.025, 0.033, respectively), while treatment response and tumor recurrence were not. Univariate analysis showed that B symptoms (P=0.004) and Ki-67 (P=0.03) were significantly associated with progression-free survival (PFS), while MYD88 L265P showed no significant association with overall survival and PFS. Multivariate analysis showed that B symptoms were significantly associated with PFS. Our study suggests that the prognostic value of MYD88 L265P in DLBCL patients with R-CHOP requires further research.

Clinical utility of recently identified diagnostic, prognostic, and predictive molecular biomarkers in mature B-cell neoplasms

Genomic profiling studies have provided new insights into the pathogenesis of mature B-cell neoplasms and have identified markers with prognostic impact. Recurrent mutations in tumor-suppressor genes (TP53, BIRC3, ATM), and common signaling pathways, such as the B-cell receptor (CD79A, CD79B, CARD11, TCF3, ID3), Toll-like receptor (MYD88), NOTCH (NOTCH1/2), nuclear factor-κB, and mitogen activated kinase signaling, have been identified in B-cell neoplasms. Chronic lymphocytic leukemia/small lymphocytic lymphoma, diffuse large B-cell lymphoma, follicular lymphoma, mantle cell lymphoma, Burkitt lymphoma, Waldenström macroglobulinemia, hairy cell leukemia, and marginal zone lymphomas of splenic, nodal, and extranodal types represent examples of B-cell neoplasms in which novel molecular biomarkers have been discovered in recent years. In addition, ongoing retrospective correlative and prospective outcome studies have resulted in an enhanced understanding of the clinical utility of novel biomarkers. This progress is reflected in the 2016 update of the World Health Organization classification of lymphoid neoplasms, which lists as many as 41 mature B-cell neoplasms (including provisional categories). Consequently, molecular genetic studies are increasingly being applied for the clinical workup of many of these neoplasms. In this review, we focus on the diagnostic, prognostic, and/or therapeutic utility of molecular biomarkers in mature B-cell neoplasms.

MicroRNA-27a restrains the immune response to mycobacterium tuberculosis infection by targeting IRAK4, a promoter of the NF-κB pathway

This study aimed to explore the influence of microRNA-27a on immune response to mycobacterium tuberculosis (Mtb) and the molecular mechanism. MiRNA-27a was screened one of the downregulated miRNAs in Mtb infected macrophages. The concentrations of IFN-γ, IL-β, IL-6, and TNF-α in THP-1 macrophages after infection with Mtb and simultaneous transfection with miR-27a mimics or inhibitor were determined by ELISA. Colony-forming unit (CFU) assay was used to determine the survival situation of THP-1 infected with Mtb after transfection with miR-27a mimics or inhibitor. We used luciferase reporter assay and western blotting to study the relationship between miR-27a and IRAK4. MiR-27a was found differential expressed in Mtb infected macrophages, and the expressions of miR-27a in Mtb-infected THP-1 were remarkably downregulated with the increase of time and dose. Compared with the control, the levels of IFN-γ, IL-β, IL-6, and TNF-α were enhanced after macrophages infected with Mtb, while further transfection of miR-27a mimics abolished the increase. IRAK4 was found the target gene of miR-27a and transfection of miR-27a mimics decreased the relative level of IRAK4. The concentration of IFN-γ, IL-β, IL-6, and TNF-α in Mtb infected macrophages were reduced significantly after transfection of miR-27a mimics, while simultaneous transfection of pcDNA-IRAK4 abolished the decrease, which is the upstream molecular of NF-κB. In conclusion, miR-27a plays a key role in immune response to Mtb infection and intervening on miR-27a may be an effective way to treat TB.

Inhibition of c-REL using siRNA increased apoptosis and decreased proliferation in pre-B ALL blasts: Therapeutic implications

The c-Rel transcription factor is a unique member of the NF-kB family that has a role in apoptosis, proliferation and cell survival. Overexpression of c-Rel is detected in many human B cell tumors, including B-cell leukemia and several cancers. The study aimed to investigate the effects of c-Rel siRNA on the proliferation and apoptosis of relapsed pre-B acute leukemia cells. The c-Rel siRNA was transfected into Leukemia cells using an Amaxa cell line Nucleofector kit L (Lonza). Quantitative real-time RT-PCR (qRT-PCR) and western blot were done to measure the expression levels of mRNA and protein, respectively. The flow cytometry was used to analyze the effect of c-Rel siRNA on the apoptosis and proliferation of Leukemia cells. Observed c-Rel expression in the 5 pre-B Acute lymphoblastic leukemia (ALL) patients were higher than the normal cells. The c-Rel siRNA transfection significantly blocked the expression of c-Rel mRNA in a time-dependent manner, leading to a strong growth inhibition and enhanced apoptosis (P<0.05). Our results demonstrated that c-Rel plays a fundamental role in the survival. Therefore, c-Rel can be considered as an attractive target for gene therapy in ALL patients. Also siRNA-mediated silencing of this gene may be a novel strategy in ALL treatment.