Influence of the methodological aspects of the dichotomization of total metabolic tumor volume measured through baseline fluorine-18 fluorodeoxyglucose PET on survival prediction in lymphoma

OBJECTIVE

The total metabolic tumor volume (TMTV) measured from fluorine-18 fluorodeoxyglucose (18F-FDG) PET can be useful for determining the prognosis of patients with lymphoma. Stratifying patients into high- and low-TMTV risk groups requires a cutoff point, which is determined through the dichotomization method. This study investigated whether different TMTV dichotomization methods influenced survival prediction in patients with lymphoma.

METHODS

We retrospectively enrolled 129 patients with lymphoma who had undergone baseline 18F-FDG PET. TMTV was calculated using a fixed standardized uptake value threshold of 4.0. A total of six methods were employed to determine the optimal TMTV cutoff point using receiver-operating characteristic curve analyses, X-Tile bioinformatics software, and the Cutoff Finder web application. The prognostic performance of each method in survival prediction was examined.

RESULTS

The median (interquartile range) TMTV was 123 cm3 (21-335 cm3). The optimal TMTV cutoff values for predicting progression-free survival (PFS) and overall survival (OS) were in the range of 144-748 cm3. The cutoff points were used to dichotomize patients into two groups with distinct prognoses. All TMTV dichotomizations were significantly predictive of PFS and OS. The survival curves showed significant differences between the high- and low-TMTV groups. The C-indices of the survival models did not significantly differ in any of the dichotomizations.

CONCLUSION

The prognostic significance of TMTV was maintained regardless of the methodological aspects of dichotomization. However, the optimal TMTV cutoff point varied according to the chosen dichotomization method. Care should be taken when establishing an optimal TMTV cutoff point for clinical use.

Clinicopathological Characteristics and Prognosis of Diffuse Large B-Cell Lymphoma in Relation to CA-125 and CA 19-9 Expression

Background: Some epithelial tumors express the carbohydrate antigen 125 (Cancer antigen-125, CA-125) and CA 19-9, especially ovarian and pancreatic tumors. Patients with non-Hodgkin lymphoma (NHL) were reported to have a close association between serum CA-125 levels and adverse prognostic factors with worse survival. We aimed to investigate CA-125 and 19-9 expression in nodal diffuse large B-cell lymphoma, not otherwise specified (DLBCL NOS) tissues using immunohistochemistry (IHC) and their relations to clinicopathological manifestations and patients' survival. Methods: 65 cases of DLBCL NOS were examined. A modified mechanical pencil tip was used to construct Manual Tissue Micro-array (TMA) blocks. Immunohistochemical staining for CA-125 and CA 19-9 was performed and scored semi-quantitatively. All relations were analyzed using established statistical methodologies. Results: Aberrant expression of CA 19-9 was detected in 12% of cases without any expression of CA-125. Moreover, 75% of the CA 19-9 positive cases were statistically significantly associated with anemia and performance status 1. Also, 75% of the CA 19-9 positive cases were females. Conclusions: CA 19-9 was aberrantly expressed in 12% of nodal DLBCL NOS cases and significantly related to anaemia and performance status but not to survival. In cases of DLBCL NOS, CA 19-9 expression cannot be considered an independent prognostic factor. CA-125 was not expressed in nodal DLBCL NOS tissues, necessitating re-evaluation studies. Therefore, it is advised to conduct more research to clarify the potential correlation between serum and tissue CA 19-9 levels and other clinic-pathological characteristics of nodal and extranodal DLBCL NOS patients.

Expression and Clinical Significance of Spi-B in B-cell Acute Lymphoblastic Leukemia

Spi-B, a member of the E26 transformation-specific (ETS) family of transcription factors, plays an important role in B cell differentiation. Spi-B also functions in development of diffuse large B-cell lymphoma; thus, we hypothesized that it may participate in leukemogenesis of B-cell acute lymphoblastic leukemia (B-ALL). To test this hypothesis, we first generated an anti-Spi-B monoclonal antibody that recognized Spi-B on formalin-fixed, paraffin-embedded tissue sections. This antibody, designated S28-5, selectively stained B cell nuclei at the pre-plasma cell stage (including centrocytes and centroblasts in germinal centers) and nuclei of plasmacytoid dendritic cells, but not fully differentiated plasma cells, T cells, macrophages, or follicular dendritic cells. Employing S28-5, we then performed immunohistochemical staining of bone marrow aspiration biopsy specimens obtained from B-ALL patients (n=62). Cases that showed stronger nuclear S28-5 signals than T-cell ALL were scored positive. In 26 (42%) of 62 specimens, leukemic cells showed nuclear Spi-B expression, and positivity was associated with patient age at diagnosis, and serum uric acid and creatinine levels. Moreover, Spi-B-positive patients demonstrated significantly shorter overall survival than did Spi-B-negative patients. These results suggest that Spi-B expression may serve as a prognostic indicator of B-ALL.

Analysis of the Correlation of Basic Fibroblast Growth Factor in Serum of Patients with Diffuse Large B-Cell Lymphoma with Clinicopathological Efficacy and International Prognostic Index

The correlation of basic fibroblast growth factor (bFGF) in serum of patients with diffuse large B-cell lymphoma (DLBCL) with clinicopathological efficacy and International Prognostic Index (IPI) is analyzed. 115 DLBCL patients admitted to our hospital for treatment from June 2020 to June 2021 are selected as the DLBCL patient group, 65 healthy subjects who received physical examination in our hospital during the same period are selected as the healthy control group, and the serum bFGF levels of DLBCL group and healthy control group are observed before treatment. The experimental results show that the serum bFGF expression of DLBCL patients is decreased significantly after chemotherapy, and the serum bFGF expression of DLBCL patients is closely related to the treatment effect, disease progression, tumor invasion, and prognosis, which has important clinical significance for judging the disease, treatment effect, and prognosis of patients.

Construction of tandem diabody (IL-6/CD20)-secreting human umbilical cord mesenchymal stem cells and its experimental treatment on diffuse large B cell lymphoma

BACKGROUND

More than 40% patients with diffuse large B cell lymphoma (DLBCL) experienced relapse or refractory (R/R) lymphoma after the standard first R-CHOP therapy. IL-6 was reportedly associated with chemotherapy resistance of rituximab. Further, mesenchymal stem cells (MSCs) are known as the potential cell vehicle for their tropism toward tumor. A MSCs-based tandem diabody for treating DLBCL is currently lacking.

METHODS

We constructed a tandem diabody (Tandab(IL-6/CD20)) with modified umbilical cord MSCs (UCMSCs) and designed a cell-based Tandab releasing system. Western blot, qPCR and immunofluorescence were used to confirm the construction and expression of lentivirus-infected UCMSCs. The vitality, apoptosis and homing abilities of UCMSCs were examined via CCK-8 assay, apoptosis, wound healing and migration analysis. Cell binding assay was used to demonstrate the targeting property of Tandab binding to CD20-positive DLBCL cells. Furthermore, we evaluated the viability of SU-DHL-2 and SU-DHL-4 by using CCK-8 and EDU assay after the treatment of UCMSCs-Tandab(IL-6/CD20).

RESULTS

Tandab protein peaked at 6273 ± 487 pg/ml in the medium on day 7 after cell culture. The proliferation and homing ability of UCMSCs did not attenuate after genetically modification. Immunofluorescence images indicated the Tandab protein bound to the lymphoma cells. UCMSCs-Tandab(IL-6/CD20) inhibited the growth of SU-DHL-2 or SU-DHL-4 cells in vitro.

CONCLUSIONS

UCMSCs-Tandab(IL-6/CD20), which bound with both tumor-associated surface antigens and pro-tumor cytokines in tumor microenvironment, might serve as a potential treatment for DLBCL, evidenced by inhibiting the growth of SU-DHL-2 or SU-DHL-4 cells.

BTK kinase activity is dispensable for the survival of diffuse large B-cell lymphoma

Inhibitors targeting Bruton's tyrosine kinase (BTK) have revolutionized the treatment for various B-cell malignancies but are limited by acquired resistance after prolonged treatment as a result of mutations in BTK. Here, by a combination of structural modeling, in vitro assays, and deep phospho-tyrosine proteomics, we demonstrated that four clinically observed BTK mutations—C481F, C481Y, C481R, and L528W—inactivated BTK kinase activity both in vitro and in diffused large B-cell lymphoma (DLBCL) cells. Paradoxically, we found that DLBCL cells harboring kinase-inactive BTK exhibited intact B cell receptor (BCR) signaling, unperturbed transcription, and optimal cellular growth. Moreover, we determined that DLBCL cells with kinase-inactive BTK remained addicted to BCR signaling and were thus sensitive to targeted BTK degradation by the proteolysis-targeting chimera. By performing parallel genome-wide CRISPR-Cas9 screening in DLBCL cells with WT or kinase-inactive BTK, we discovered that DLBCL cells with kinase-inactive BTK displayed increased dependence on Toll-like receptor 9 (TLR9) for their growth and/or survival. Our study demonstrates that the kinase activity of BTK is not essential for oncogenic BCR signaling and suggests that BTK’s noncatalytic function is sufficient to sustain the survival of DLBCL.

The Methylation of the p53 Targets the Genes MIR-203, MIR-129-2, MIR-34A and MIR-34B/C in the Tumor Tissue of Diffuse Large B-Cell Lymphoma

The regulation of oncogenes by microRNA is a focus of medical research. hsa-miR-203, hsa-mir-129, hsa-miR-34a, hsa-miR-34b and hsa-miR-34c are oncosuppressive microRNAs that mediate the antitumor activity of p53. We seek to evaluate the frequencies, co-occurrence and clinical significance of the methylation of the MIR-203, MIR-129-2, MIR-34A and MIR-34B/C genes in the tumor tissue of diffuse large B-cell lymphoma (DLBCL). The methylation was assessed in 73 samples of DLBCL and in 11 samples of lymph nodes of reactive follicular hyperplasia by Methyl-Specific Polymerase Chain Reaction (MS-PCR) and Methylation-Sensitive High-Resolution-Melting (MS-HRM) methods. All four studied genes were not methylated in the tissue of reactive lymphatic nodes. The methylation frequencies of the MIR-129-2, MIR-203, MIR-34A and MIR-34B/C genes in lymphoma tissue were 67%, 66%, 27% and 62%, respectively. Co-occurrence of MIR-203, MIR-129-2 and MIR-34B/C genes methylation, as well as the methylation of MIR-34B/C and MIR-34A pair genes were detected. The MIR-34A gene methylation was associated with increased International Prognostic Index (IPI) (p = 0.002), whereas the MIR-34B/C (p = 0.026) and MIR-203 (p = 0.011) genes’ methylation was connected with Ki-67 expression level in tumor tissue at more than 45%. We found an increasing frequency of detection of MIR-34A gene methylation in the group of patients with the Germinal-Center B-cell like (GCB-like) subtype of DLBCL (p = 0.046). There was a trend towards a decrease in the remission frequency after the first line of therapy (p = 0.060) and deterioration in overall survival (OS) (p = 0.162) in patients with DLBCL with methylation of the MIR-34A promoter. The methylation of the MIR-34A, MIR-34B/C, MIR-129-2 and MIR-203 genes in DLBCL is tumor-specific and occurs in combination. The methylation of the studied genes may be a potential differential diagnostic biomarker to distinguish between lymphoma and reactive lymph nodes, while its independent predictive value has not been confirmed yet.

Super-enhancer hypermutation alters oncogene expression in B cell lymphoma

Diffuse large B cell lymphoma (DLBCL) is the most common B cell non-Hodgkin lymphoma and remains incurable in around 40% of patients. Efforts to sequence the coding genome identified several genes and pathways that are altered in this disease, including potential therapeutic targets1-5. However, the non-coding genome of DLBCL remains largely unexplored. Here we show that active super-enhancers are highly and specifically hypermutated in 92% of samples from individuals with DLBCL, display signatures of activation-induced cytidine deaminase activity, and are linked to genes that encode B cell developmental regulators and oncogenes. As evidence of oncogenic relevance, we show that the hypermutated super-enhancers linked to the BCL6, BCL2 and CXCR4 proto-oncogenes prevent the binding and transcriptional downregulation of the corresponding target gene by transcriptional repressors, including BLIMP1 (targeting BCL6) and the steroid receptor NR3C1 (targeting BCL2 and CXCR4). Genetic correction of selected mutations restored repressor DNA binding, downregulated target gene expression and led to the counter-selection of cells containing corrected alleles, indicating an oncogenic dependency on the super-enhancer mutations. This pervasive super-enhancer mutational mechanism reveals a major set of genetic lesions deregulating gene expression, which expands the involvement of known oncogenes in DLBCL pathogenesis and identifies new deregulated gene targets of therapeutic relevance.

Targeting a Novel G-Quadruplex in the CARD11 Oncogene Promoter with Naptho(2,1-b)furan-1-ethanol,2-nitro- Requires the Nitro Group

The aggressive nature of the activated B cell such as (ABC) subtype of diffuse large B cell (DLBCL) is frequently associated with altered B cell Receptor (BCR) signaling through the activation of key components including the scaffolding protein, CARD11. Most inhibitors, such as ibrutinib, target downstream BCR kinases with often modest and temporary responses for DLBCL patients. Here, we pursue an alternative strategy to target the BCR pathway by leveraging a novel DNA secondary structure to repress transcription. We discovered that a highly guanine (G)-rich element within the CARD11 promoter forms a stable G-quadruplex (G4) using circular dichroism and polymerase stop biophysical techniques. We then identified a small molecule, naptho(2,1-b)furan-1-ethanol,2-nitro- (NSC373981), from a fluorescence-resonance energy transfer-based screen that stabilized CARD11 G4 and inhibited CARD11 transcription in DLBCL cells. In generating and testing analogs of NSC373981, we determined that the nitro group is likely essential for the downregulation of CARD11 and interaction with CARD11 G4, and the removal of the ethanol side chain enhanced this activity. Of note, the expression of BCL2 and MYC, two other key oncogenes in DLBCL pathology with known promoter G4 structures, were often concurrently repressed with NSC373981 and the highly potent R158 analog. Our findings highlight a novel approach to treat aggressive DLBCL by silencing CARD11 gene expression that warrants further investigation.

Systems Drug Discovery for Diffuse Large B Cell Lymphoma Based on Pathogenic Molecular Mechanism via Big Data Mining and Deep Learning Method

Diffuse large B cell lymphoma (DLBCL) is an aggressive heterogeneous disease. The most common subtypes of DLBCL include germinal center b-cell (GCB) type and activated b-cell (ABC) type. To learn more about the pathogenesis of two DLBCL subtypes (i.e., DLBCL ABC and DLBCL GCB), we firstly construct a candidate genome-wide genetic and epigenetic network (GWGEN) by big database mining. With the help of two DLBCL subtypes’ genome-wide microarray data, we identify their real GWGENs via system identification and model order selection approaches. Afterword, the core GWGENs of two DLBCL subtypes could be extracted from real GWGENs by principal network projection (PNP) method. By comparing core signaling pathways and investigating pathogenic mechanisms, we are able to identify pathogenic biomarkers as drug targets for DLBCL ABC and DLBCL GCD, respectively. Furthermore, we do drug discovery considering drug-target interaction ability, drug regulation ability, and drug toxicity. Among them, a deep neural network (DNN)-based drug-target interaction (DTI) model is trained in advance to predict potential drug candidates holding higher probability to interact with identified biomarkers. Consequently, two drug combinations are proposed to alleviate DLBCL ABC and DLBCL GCB, respectively.

PLAGL2 Promotes the Proliferation and Migration of Diffuse Large B-cell Lymphoma Cells via Wnt/β-catenin Pathway

OBJECTIVE

Pleomorphic adenoma gene like-2 (PLAGL2) belongs to PLAG protein family and functions as a zinc finger transcriptional factor to participate in the cellular processes, including cell transformation, migration, and apoptosis. Increasing evidence has shown the oncogenic role of PLAGL2 in various cancers, while the potential molecular mechanism and biology roles of PLAGL2 in diffuse large B-cell lymphoma (DLBCL) are still unclear.

METHODS

Expression of PLAGL2 was found to be elevated in DLBCL cells. Functional assays showed that silence of PLAGL2 suppressed cell proliferation and reduced the cell migration and invasion in DLBCL. The cell proliferation and metastasis in DLBCL were promoted by over-expression of PLAGL2. Moreover, the protein expression of E-cadherin was increased, while the protein expressions of N-cadherin and vimentin were decreased in DLBCL cells by knockdown of PLAGL2. However, over-expression of PLAGL2 promoted epithelial to mesenchymal transition (EMT) of DLBCL through down-regulation of E-cadherin, and up-regulations of N-cadherin and vimentin.

RESULTS

Over-expression of PLAGL2 up-regulated β-catenin and c-myc, while down-regulated axis inhibition protein 2 (AXIN2) and adenomatous polyposis coli (APC) in DLBCL. Knockdown of PLAGL2 suppressed the activation of Wnt/β-catenin pathway in DLBCL through downregulating β-catenin and c-myc but upregulating AXIN2 and APC. Xenograft model also demonstrated that interference of PLAGL2 repressed the in vivo tumor growth of DLBCL.

CONCLUSION

In conclusion, PLAGL2 promoted the malignancy of DLBCL through activation of Wnt/β-catenin pathway.

Acquired Resistance to EZH2 Inhibitor GSK343 Promotes the Differentiation of Human DLBCL Cell Lines toward an ABC-Like Phenotype

Diffuse large B-cell lymphoma (DLBCL) accounts for 40% of non-Hodgkin lymphoma, and 30% to 40% of patients will succumb to relapsed/refractory disease (rrDLBCL). Patients with rrDLBCL generally have low long-term survival rates due to a lack of efficient salvage therapies. Small-molecule inhibitors targeting the histone methyltransferase EZH2 represent an emerging group of novel therapeutics that show promising clinical efficacy in patients with rrDLBCL. The mechanisms that control acquired resistance to this class of targeted therapies, however, remain poorly understood. Here, we develop a model of resistance to the EZH2 inhibitor (EZH2i) GSK343 and use RNA-seq data and in vitro investigation to show that GCB (germinal center B-cell)-DLBCL cell lines with acquired drug resistance differentiate toward an ABC (activated B-cell)-DLBCL phenotype. We further observe that the development of resistance to GSK343 is sufficient to induce cross-resistance to other EZH2i. Notably, we identify the immune receptor SLAMF7 as upregulated in EZH2i-resistant cells, using chromatin immunoprecipitation profiling to uncover the changes in chromatin landscape remodeling that permit this altered gene expression. Collectively, our data reveal a previously unreported response to the development of EZH2i resistance in DLBCL, while providing strong rationale for pursuing investigation of dual-targeting of EZH2 and SLAMF7 in rrDLBCL.

Significance of Single-cell Level Dual Expression of BCL2 and MYC Determined With Multiplex Immunohistochemistry in Diffuse Large B-Cell Lymphoma

Diffuse large B-cell lymphoma (DLBCL) is a fatal heterogenous neoplasm. Recent clinical trials have failed partly due to nebulous criteria for defining high-risk patients. Patients with double-expresser lymphoma (DEL) have a poor prognosis and are resistant to conventional treatment. However, many diagnostic and clinical controversies still surround DEL partly due to the arbitrariness of criteria for the diagnosis of DEL. In this study, we suggest a refined method for diagnosing DEL by evaluating the concurrent expression of BCL2 and MYC at the single-cell level (dual-protein-expressing lymphoma [DUEL]). For the proof of concept, a multiplex immunofluorescence assay for CD20, BCL2, and MYC was performed and quantitatively analyzed using spectral image analysis in patients. The analysis results and clinical applicability were verified by using dual-color immunohistochemistry performed on 353 independent multicenter patients who had been uniformly treated with standard therapy. DUEL showed significantly worse overall survival (OS) and event-free survival (EFS) (P=0.00011 and 0.00035, respectively). DUEL status remained an independent adverse prognostic variable with respect to the International Prognostic Index risk and the cell of origin. Moreover, the advantage of determining DUEL status by dual-color immunohistochemistry was shown by more robust classification and more homogeneous high-risk subgroup patient identification in both training (n=271) (OS: P<0.0001; EFS: P<0.0001) and validation sets (n=82) (OS: P=0.0087; EFS: P<0.0001). This concept of DUEL is more consistent with carcinogenesis and has greater practical utility, hence it may provide a better basis for both basic and clinical research for the development of new therapeutics.

The Role of the MYC/miR-150/MYB/ZDHHC11 Network in Hodgkin Lymphoma and Diffuse Large B-Cell Lymphoma

We previously described involvement of the MYC/miR-150/MYB/ZDHHC11 network in the growth of Burkitt lymphoma (BL) cells. Here we studied the relevance of this network in the two other B-cell lymphomas: Hodgkin lymphoma (HL) and diffuse large B-cell lymphoma (DLBCL). Expression levels of the network components were assessed at the RNA and protein level. The effect of modulating levels of the network components on cell growth was determined through GFP competition assay. AGO2-RNA immunoprecipitation was performed to validate targeting by miR-150. Expression levels of MYC, MYB and ZDHHC11 were increased, while miR-150 levels were decreased similar to the pattern observed in BL. The knockdown of MYC, MYB and ZDHHC11 decreased the growth of HL and DLBCL cells. In contrast, overexpression of miR-150 did not induce clear phenotypes in HL, and limited the effects in DLBCL. This could not be explained by the differences in overexpression levels. Furthermore, we showed that in HL, ZDHHC11 and MYB are efficiently targeted by miR-150. To conclude, MYC, MYB and ZDHHC11 are critical for the growth of HL and DLBCL cells consistent with the role observed in BL cells, while low endogenous miR-150 levels appeared to be less critical for the growth of HL and DLBCL cells despite the effective targeting of ZDHHC11 and MYB.

MiR-665 suppresses the progression of diffuse large B cell lymphoma (DLBCL) through targeting LIM and SH3 protein 1 (LASP1)

Diffuse large B cell lymphoma (DLBCL), the most common type of non-Hodgkin lymphoma worldwide, is aggressive and highly heterogeneous. MiR-665 was found to be lowly expressed in serum exosomes of DLBCL patients and in DLBCL cell lines, but its function in DLBCL progression remains unclear. In this study, miR-665 was overexpressed in SU-DHL-4 cells via miR-665 mimics and knocked down in FARAGE cells via miR-665 inhibitor. Knockdown of miR-665 promoted DLBCL cell proliferation and invasion and decreased cell apoptosis, whereas miR-665 overexpression showed opposite effects on DLBCL cell malignant behaviors. Luciferase reporter assay confirmed LIM and SH3 protein 1 (LASP1) and MYC as target genes of miR-665. Moreover, the expression of LASP1 was negatively correlated with that of miR-665 in LDLBCL cells. LASP1 has tumor-promoting property and its inhibition abolished the effect of miR-665 knockdown on DLBCL cell proliferation, invasion, and apoptosis. SU-DHL-4 cells were inoculated into the flank of nude mice, followed by orthotopic injection with miR-665 agomir. MiR-665 overexpression restricted tumor growth in vivo. Thus, we demonstrates that miR-665 suppresses DLBCL cell malignant behaviors by inhibiting cell proliferation and invasion and inducing apoptosis via targeting LASP1 and MYC, suggesting the importance of miR-665 in DLBCL progression.

Knockdown of zinc finger protein 267 suppresses diffuse large B-cell lymphoma progression, metastasis, and cancer stem cell properties

Zinc finger protein 267 (ZNF267) is a member of the Kruppel-like transcription factor family, which regulates various biological processes such as cell proliferation and differentiation. However, the biological significance of ZNF267 and its potential role in diffuse large B-cell lymphoma (DLBCL) remain to be documented. Experiments were herein conducted to study the role of ZNF267 in DLBCL. real-time quantitative reverse transcription PCR and Western blotting assays were conducted to detect the expression of ZNF267 in tissues and cells. Tissue microarray and bioinformatics analyses of public data were also done to detect the expression status and clinical significance of ZNF267. Functional cell experiments including CCK8 assay, colony formation assay, 5-ethynyl-2'-deoxyuridine (EDU) assay, terminal deoxynucleotidyl transferase biotin-dUTP nick end labeling (TUNEL) assay, transwell assay, and wound healing assay were conducted to study the effects of ZNF267 knockdown and overexpression on cell proliferation and mobility. Xenograft assay was also conducted to confirm the effects of ZNF267 knockdown in vivo. In the present study, we found ZNF267 was significantly upregulated in DLBCL and predicted a poor survival outcome based on the bioinformatics analysis. Functionally, the knockdown of ZNF267 resulted in less cell proliferation and mobility, whereas the overexpression led to enhanced cell proliferation and mobility. Animal experiments also confirmed that ZNF267 silence contributed to less tumor growth and less lung metastasis. Further analysis showed that ZFN267 knockdown resulted in decreased epithelial-mesenchymal transition (EMT) and cancer stem cell (CSC) properties. Our results suggest that ZNF267 is an oncogene in DLBCL and its silence could compromise the aggression of DLBCL, which makes ZNF267 a promising therapeutic target.

Expression and Prognostic Value of PIK3CA, VEGF, IL-8, IL-10, and RIP2 in Diffuse Large B-Cell Lymphoma

BACKGROUND

To explore clinical features and prognostic value of vascular endothelial growth factor (VEGF), interleukin (IL) 8, IL-10, phosphatidylinositol-4,5-bisphosphate 3-kinase catalytic subunit alpha (PIK3CA), and receptor-interacting protein-2 (RIP2) in diffuse large B-cell lymphoma (DLBCL).

METHODS

A total of 68 DLBCL patients admitted to the Affiliated Hospital of Hebei Engineering University from January 2017 to June 2021 were included in this retrospective analysis. Serum VEGF was detected by enzyme-linked immunosorbent assay, serum IL-8 and IL-10 were detected by chemiluminescent enzyme immunoassay, and expression of PIK3CA and RIP2 in tumors was detected by immunohistochemistry. The correlation between clinical features of DLBCL and tumor-related index were analyzed. Cox regression was conducted to explore risk factors and hazard ratio.

RESULTS

The serum level or expressions of VEGF, IL-8, IL-10, and RIP2 were significantly elevated with the increase of Ann Arbor Stage, International Prognostic Index (IPI) scores, Eastern Cooperative Oncology Group (ECOG) scores, serum lactate dehydrogenase (LDH) level, and the number of extranodal sites (all P < 0.05). Beside, these serum indexes were significantly higher in patients with the presence of extranodal involvement and germinal center B-cell (GCB), but significantly lower in patients with the presence of bone marrow involvement (all P < 0.05). Cox regression analysis for overall survival revealed that high expression of VEGF, high level of serum IL-8, serum IL-10, and RIP2, Ann Arbor Stage (III-IV), number of extranodal sites (>1), serum LDH level (≥245 U/L), IPI scores (3-5), ECOG scores (≥2), and bone marrow involvement were independent risk factors for the prognosis of DLBCL patients (all P < 0.05).

CONCLUSION

The serum levels of VEGF, IL-8, and IL-10, as well as the expression of RIP2 and PIK3CA in tumor tissues, were highly correlated to clinical features of DLBCL, and high expression level of these indexes may have adverse effects for the prognosis of DLBCL patients.

Chromosome Region Maintenance 1 (XPO1/CRM1) as an Anticancer Target and Discovery of Its Inhibitor

Chromosome region maintenance 1 (CRM1) is a major nuclear export receptor protein and contributes to cell homeostasis by mediating the transport of cargo from the nucleus to the cytoplasm. CRM1 is a therapeutic target comprised of several tumor types, including osteosarcoma, multiple myeloma, gliomas, and pancreatic cancer. In the past decade, dozens of CRM1 inhibitors have been discovered and developed, including KPT-330, which received FDA approval for multiple myeloma (MM) and diffuse large B-cell lymphoma (DLBCL) in 2019 and 2020, respectively. This review summarizes the biological functions of CRM1, the current understanding of the role CRM1 plays in cancer, the discovery of CRM1 small-molecule inhibitors, preclinical and clinical studies on KPT-330, and other recently developed inhibitors. A new CRM1 inhibition mechanism and structural dynamics are discussed. Through this review, we hope to guide the future design and optimization of CRM1 inhibitors.

Cohesin Core Complex Gene Dosage Contributes to Germinal Center Derived Lymphoma Phenotypes and Outcomes

The cohesin complex plays critical roles in genomic stability and gene expression through effects on 3D architecture. Cohesin core subunit genes are mutated across a wide cross-section of cancers, but not in germinal center (GC) derived lymphomas. In spite of this, haploinsufficiency of cohesin ATPase subunit Smc3 was shown to contribute to malignant transformation of GC B-cells in mice. Herein we explored potential mechanisms and clinical relevance of Smc3 deficiency in GC lymphomagenesis. Transcriptional profiling of Smc3 haploinsufficient murine lymphomas revealed downregulation of genes repressed by loss of epigenetic tumor suppressors Tet2 and Kmt2d. Profiling 3D chromosomal interactions in lymphomas revealed impaired enhancer-promoter interactions affecting genes like Tet2, which was aberrantly downregulated in Smc3 deficient lymphomas. Tet2 plays important roles in B-cell exit from the GC reaction, and single cell RNA-seq profiles and phenotypic trajectory analysis in Smc3 mutant mice revealed a specific defect in commitment to the final steps of plasma cell differentiation. Although Smc3 deficiency resulted in structural abnormalities in GC B-cells, there was no increase of somatic mutations or structural variants in Smc3 haploinsufficient lymphomas, suggesting that cohesin deficiency largely induces lymphomas through disruption of enhancer-promoter interactions of terminal differentiation and tumor suppressor genes. Strikingly, the presence of the Smc3 haploinsufficient GC B-cell transcriptional signature in human patients with GC-derived diffuse large B-cell lymphoma (DLBCL) was linked to inferior clinical outcome and low expression of cohesin core subunits. Reciprocally, reduced expression of cohesin subunits was an independent risk factor for worse survival int DLBCL patient cohorts. Collectively, the data suggest that Smc3 functions as a bona fide tumor suppressor for lymphomas through non-genetic mechanisms, and drives disease by disrupting the commitment of GC B-cells to the plasma cell fate.

Proteomic-Based Analysis of Hypoxia- and Physioxia-Responsive Proteins and Pathways in Diffuse Large B-Cell Lymphoma

Hypoxia is a common feature in most tumors, including hematological malignancies. There is a lack of studies on hypoxia- and physioxia-induced global proteome changes in lymphoma. Here, we sought to explore how the proteome of diffuse large B-cell lymphoma (DLBCL) changes when cells are exposed to acute hypoxic stress (1% of O₂) and physioxia (5% of O₂) for a long-time. A total of 8239 proteins were identified by LC–MS/MS, of which 718, 513, and 486 had significant changes, in abundance, in the Ri-1, U2904, and U2932 cell lines, respectively. We observed that changes in B-NHL proteome profiles induced by hypoxia and physioxia were quantitatively similar in each cell line; however, differentially abundant proteins (DAPs) were specific to a certain cell line. A significant downregulation of several ribosome proteins indicated a translational inhibition of new ribosome protein synthesis in hypoxia, what was confirmed in a pathway enrichment analysis. In addition, downregulated proteins highlighted the altered cell cycle, metabolism, and interferon signaling. As expected, the enrichment of upregulated proteins revealed terms related to metabolism, HIF1 signaling, and response to oxidative stress. In accordance to our results, physioxia induced weaker changes in the protein abundance when compared to those induced by hypoxia. Our data provide new evidence for understanding mechanisms by which DLBCL cells respond to a variable oxygen level. Furthermore, this study reveals multiple hypoxia-responsive proteins showing an altered abundance in hypoxic and physioxic DLBCL. It remains to be investigated whether changes in the proteomes of DLBCL under normoxia and physioxia have functional consequences on lymphoma development and progression.

PD-1 and LAG-3 Checkpoint Blockade: Potential Avenues for Therapy in B-Cell Lymphoma

The dependence of cancer on an immunotolerant tumor microenvironment (TME) is well established. Immunotherapies that overcome tumor-induced immune suppression have been central to recent advancements in oncology. This is highlighted by the success of agents that interrupt PD-1 mediated immune suppression in a range of cancers. However, while PD-1 blockade has been paradigm-shifting in many malignancies, the majority of cancers show high rates of primary resistance to this approach. This has led to a rapid expansion in therapeutic targeting of other immune checkpoint molecules to provide combination immune checkpoint blockade (ICB), with one such promising approach is blockade of Lymphocyte Activation Gene 3 (LAG-3). Clinically, lymphoproliferative disorders show a wide spectrum of responses to ICB. Specific subtypes including classical Hodgkin lymphoma have demonstrated striking efficacy with anti-PD-1 therapy. Conversely, early trials of ICB have been relatively disappointing in common subtypes of Non-Hodgkin lymphoma. In this review, we describe the TME of common lymphoma subtypes with an emphasis on the role of prominent immune checkpoint molecules PD-1 and LAG3. We will also discuss current clinical evidence for ICB in lymphoma and highlight key areas for further investigation where synergistic dual checkpoint blockade of LAG-3 and PD-1 could be used to overcome ICB resistance.

Risk stratification model based on VEGF and International Prognostic Index accurately identifies low-risk diffuse large B-cell lymphoma patients in the rituximab era

Vascular endothelial growth factor affects the invasiveness of solid tumors by regulating angiogenesis. However, it is not clear whether VEGF could be used to predict the prognosis of DLBCL in the era of rituximab-based immunotherapy. We conducted a retrospective study to explore response to therapy and the prognostic value of VEGF on DLBCL in the rituximab era. The subjects were 65 patients with a histological diagnosis of DLBCL from the Affiliated Hospital of Xuzhou Medical University. Kaplan-Meier analysis was performed to estimate the cumulative survival rate of patients with different VEGF and IPI levels, and comparisons between groups were made using the log-rank test. DLBCL patients with elevated VEGF were more likely to have extranodal involvement, advanced stage, Myc/Bcl-2 double expression, and a higher Ki-67 score. Elevated VEGF was associated with poor therapeutic response and survival. When patients were divided into low, low-intermediate, high-intermediate and high-risk groups using the V-IPI model based on VEGF and IPI, PFS rates were 94.4, 74.1, 40.6 and 14.8%, respectively. This model better identified low-risk patients than IPI (85.9, 88.9, 37 and 7.8%). Our results demonstrate that VEGF predicts therapeutic response in DLBCL and the V-IPI model accurately predicts PFS of low-risk DLBCL in the rituximab era.

Maculopathy Associated With Osmotic Blood- Brain Barrier Disruption and Chemotherapy in Patients With Primary CNS Lymphoma

BACKGROUND AND OBJECTIVE

To describe the incidence, characteristics, and risk factors of a pigmentary maculopathy in patients with primary central nervous system (CNS) lymphoma treated with blood-brain barrier disruption (BBBD) therapy.

PATIENTS AND METHODS

This retrospective chart review included patients with biopsy-proven primary CNS lymphoma treated with or without BBBD therapy who underwent an ophthalmic examination after starting systemic treatment. Clinical data and all available retinal imaging were analyzed.

RESULTS

Fifty-eight patients met inclusion criteria. Twenty-one of 36 patients treated with BBBD therapy had a bilateral pigmentary maculopathy. None of the 22 patients treated with conventional chemotherapy had similar changes. Additional findings in patients treated with BBBD included geographic retinal pigment epithelium atrophy, subretinal fluid, and in one case, choroidal neovascularization. Some cases of maculopathy resulted in reduced visual acuity. The presence of a pigmentary maculopathy was associated with a higher number of BBBD treatment sessions (20.1 vs 13.3, P = .016), but not vitreoretinal lymphoma involvement or intravitreal methotrexate injections.

CONCLUSION

In this cohort, 58.3% of patients with primary CNS lymphoma treated with BBBD and chemotherapy were found to have a bilateral pigmentary maculopathy. This maculopathy can result in reduced visual acuity and is associated with the number of BBBD treatment sessions. [Ophthalmic Surg Lasers Imaging Retina. 2020;51:S5-S12.].

Mitochondria and nucleus cross-talk: Signaling in metabolism, apoptosis, and differentiation, and function in cancer

The cross-talk between the mitochondrion and the nucleus regulates cellular functions, including differentiation and adaptation to stress. Mitochondria supply metabolites for epigenetic modifications and other nuclear-associated activities and certain mitochondrial proteins were found in the nucleus. The voltage-dependent anion channel 1 (VDAC1), localized at the outer mitochondrial membrane (OMM) is a central protein in controlling energy production, cell growth, Ca2+ homeostasis, and apoptosis. To alter the cross-talk between the mitochondria and the nucleus, we used specific siRNA to silence the expression of VDAC1 in glioblastoma (GBM) U87-MG and U118-MG cell-derived tumors, and then monitored the nuclear localization of mitochondrial proteins and the methylation and acetylation of histones. Depletion of VDAC1 from tumor cells reduced metabolism, leading to inhibition of tumor growth, and several tumor-associated processes and signaling pathways linked to cancer development. In addition, we demonstrate that certain mitochondrial pro-apoptotic proteins such as caspases 3, 8, and 9, and p53 were unexpectedly overexpressed in tumors, suggesting that they possess additional non-apoptotic functions. VDAC1 depletion and metabolic reprograming altered their expression levels and subcellular localization, specifically their translocation to the nucleus. In addition, VDAC1 depletion also leads to epigenetic modifications of histone acetylation and methylation, suggesting that the interchange between metabolism and cancer signaling pathways involves mitochondria-nucleus cross-talk. The mechanisms regulating mitochondrial protein trafficking into and out of the nucleus and the role these proteins play in the nucleus remain to be elucidated.

PD1/PD-L1 Expressions in Plasmablastic Lymphoma with Clinicopathological Correlation

The activation of the programmed cell death one (PD1)/PD1 ligand (PD-L1) immune checkpoint pathway is a mechanism of immune evasion characterized by the upregulation of PD-L1 expression by tumor cells and by the tumor microenvironment. This activation leads to the inhibition of PD1-positive T cells and to a decrease in the anti-tumor immune response. Plasmablastic lymphoma (PBL) is an aggressive type of large B-cell lymphoma with limited studies on the frequency of PD1 and PD-L1 expressions and their clinical impact. As PBL is associated with immune suppression in immunocompromised individuals, we hypothesize that the PD1/PD-L1 axis may be relevant in this type of lymphoma. Our study demonstrates a subset of PBL cases with a higher PD-L1 expression by tumor cells [nPD-L1^high, in 4 of 21 (19%) cases] and by tumor microenvironment [macrophages/stromal cells, sPD-L1^high, in 9 of 21 (43%) cases]. While nPD-L1 expression showed no significant correlation with PD1 expression on tumor-infiltrating lymphocytes, or other clinicopathological parameters, it positively correlated with sPD-L1 expression. Moreover, patients with nPD-L1^high had a tendency towards a shorter overall survival (median 9.3 vs. 25.5 months in nPD-L1^low patients). In conclusion, our study provides a rationale to identify, by immunohistochemistry, a subset of nPD-L1^high patients who may benefit from clinical trials of PD1/PD-L1 checkpoint blockade. Further studies on large cohorts are needed to investigate prognostic and predictive biomarkers for the PD1/PD-L1 pathway in PBL patients.