GLUT1 expression patterns in different Hodgkin lymphoma subtypes and progressively transformed germinal centers

Identification and Interpretation of eQTL and eGenes for Hodgkin Lymphoma Susceptibility

Genome-wide association studies (GWAS) have revealed approximately 100 genomic signals associated with Hodgkin lymphoma (HL); however, their target genes and underlying mechanisms causing HL susceptibility remain unclear. In this study, transcriptome-wide analysis of expression quantitative trait loci (eQTL) was conducted to identify target genes associated with HL GWAS signals. A mixed model, which explains polygenic regulatory effects by the genomic covariance among individuals, was implemented to discover expression genes (eGenes) using genotype data from 462 European/African individuals. Overall, 80 eGenes were identified to be associated with 20 HL GWAS signals. Enrichment analysis identified apoptosis, immune responses, and cytoskeletal processes as functions of these eGenes. The eGene of rs27524 encodes ERAP1 that can cleave peptides attached to human leukocyte antigen in immune responses; its minor allele may help Reed-Sternberg cells to escape the immune response. The eGene of rs7745098 encodes ALDH8A1 that can oxidize the precursor of acetyl-CoA for the production of ATP; its minor allele may increase oxidization activity to evade apoptosis of pre-apoptotic germinal center B cells. Thus, these minor alleles may be genetic risk factors for HL susceptibility. Experimental studies on genetic risk factors are needed to elucidate the underlying mechanisms of HL susceptibility and improve the accuracy of precision oncology.

Current Status of Novel Agents for the Treatment of B Cell Malignancies: What's Coming Next?

Resistance to death is one of the hallmarks of human B cell malignancies and often contributes to the lack of a lasting response to today's commonly used treatments. Drug discovery approaches designed to activate the death machinery have generated a large number of inhibitors of anti-apoptotic proteins from the B-cell lymphoma/leukemia 2 family and the B-cell receptor (BCR) signaling pathway. Orally administered small-molecule inhibitors of Bcl-2 protein and BCR partners (e.g., Bruton's tyrosine kinase and phosphatidylinositol-3 kinase) have already been included (as monotherapies or combination therapies) in the standard of care for selected B cell malignancies. Agonistic monoclonal antibodies and their derivatives (antibody-drug conjugates, antibody-radioisotope conjugates, bispecific T cell engagers, and chimeric antigen receptor-modified T cells) targeting tumor-associated antigens (TAAs, such as CD19, CD20, CD22, and CD38) are indicated for treatment (as monotherapies or combination therapies) of patients with B cell tumors. However, given that some patients are either refractory to current therapies or relapse after treatment, novel therapeutic strategies are needed. Here, we review current strategies for managing B cell malignancies, with a focus on the ongoing clinical development of more effective, selective drugs targeting these molecules, as well as other TAAs and signaling proteins. The observed impact of metabolic reprogramming on B cell pathophysiology highlights the promise of targeting metabolic checkpoints in the treatment of these disorders.

Coexpression of MCT1 and MCT4 in ALK-positive Anaplastic Large Cell Lymphoma: Diagnostic and Therapeutic Implications

In solid tumors, glycolytic cancer or stromal cells export lactates through monocarboxylate transporter (MCT) 4, while oxidative cancer or stromal cells take up lactates as metabolic fuels or signaling molecules through MCT1. CD147 acts as a chaperone of MCT1 or MCT4. Unlike solid tumors, malignant lymphomas have a peculiar tumor microenvironment. To investigate the metabolic phenotype of malignant lymphoma associated with lactate transport, we analyzed immunohistochemical expressions of MCT1, MCT4, and CD147 in 247 cases of various malignant lymphomas. Surprisingly, both MCT1 and MCT4 were diffusely expressed on tumor cell membranes in all cases (11/11, 100%) of anaplastic lymphoma kinase (ALK) (+) anaplastic large cell lymphoma (ALCL). In contrast, only MCT1 was diffusely expressed in tumor cells of ALK(-) ALCL, as well as in B-cell, natural killer/T-cell, T-cell, and classic Hodgkin lymphomas. In these lymphomas, MCT4 expression was mostly localized to adjacent stromal cells. The pattern of diffuse membranous MCT1 and partial MCT4 expressions in tumor cells was observed in 1 case each of peripheral T-cell lymphoma (1/15, 6.7%) and multiple myeloma (1/34, 2.9%). CD147 was diffusely expressed in all types of lymphoma tumor and/or stromal cells. In conclusion, ALK(+) ALCL has a unique metabolism showing high coexpression of MCT1 and MCT4 in tumor cells. Because only ALK(+) ALCL overexpresses MCT4, immunostaining for MCT4 together with ALK is very useful for differential diagnosis from ALK(-) ALCL or peripheral T-cell lymphoma. Moreover, dual targeting against MCT1 and MCT4 would be an appropriate therapeutic approach for ALK(+) ALCL.

Dasatinib associated lymphadenopathy in a chronic myeloid leukemia patient: A case report

RATIONALE

Dasatinib associated lymphadenopathy (DAL) is a rare adverse event in chronic myeloid leukemia patients (CML). A case of voluminous lymphadenopathy in the context of DAL is presented.

PATIENT CONCERNS

A 40-year-old male patient was diagnosed with BCR-ABL1 positive chronic stage CML 2 years ago and achieved complete molecular response on nilotinib, which was switched to dasatinib due to nilotinib intolerance. After 5 months on dasatinib, the patient presented with a large mass in the axillary region.

DIAGNOSIS

Common infectious and autoimmune etiologies of lymphadenopathy were ruled out. The positron emission tomography/computed tomography (PET/CT) demonstrated a hypermetabolic lymphadenopathy highly suspicious of lymphoma. The subsequent biopsy excluded lymphoma or extramedullary blastic transformation of CML and revealed reactive lymphadenopathy with mixed (cortical and paracortical) pattern. Clinical history and clinicopathological correlation suggested the diagnosis of DAL.

INTERVENTION

Dasatinib was discontinued and the patient remained in close follow-up. TKI treatment with nilotinib was reinitiated.

OUTCOMES

Lymphadenopathy resolved clinically at 4 weeks and normalization of PET/CT findings was documented at 9 weeks after cessation of the drug. TKI treatment with nilotinib was reinitiated with good tolerance.

LESSONS

DAL may present with voluminous lymphadenopathy consistent with malignancy in clinical and imaging workup. We describe the spectrum of lesions associated with DAL and identify common features with drug-induced lymphadenopathy.

Interim PET-results for prognosis in adults with Hodgkin lymphoma: a systematic review and meta-analysis of prognostic factor studies

BACKGROUND

Hodgkin lymphoma (HL) is one of the most common haematological malignancies in young adults and, with cure rates of 90%, has become curable for the majority of individuals. Positron emission tomography (PET) is an imaging tool used to monitor a tumour's metabolic activity, stage and progression. Interim PET during chemotherapy has been posited as a prognostic factor in individuals with HL to distinguish between those with a poor prognosis and those with a better prognosis. This distinction is important to inform decision-making on the clinical pathway of individuals with HL.

OBJECTIVES

To determine whether in previously untreated adults with HL receiving first-line therapy, interim PET scan results can distinguish between those with a poor prognosis and those with a better prognosis, and thereby predict survival outcomes in each group.

SEARCH METHODS

We searched MEDLINE, Embase, CENTRAL and conference proceedings up until April 2019. We also searched one trial registry (ClinicalTrials.gov).

SELECTION CRITERIA

We included retrospective and prospective studies evaluating interim PET scans in a minimum of 10 individuals with HL (all stages) undergoing first-line therapy. Interim PET was defined as conducted during therapy (after one, two, three or four treatment cycles). The minimum follow-up period was at least 12 months. We excluded studies if the trial design allowed treatment modification based on the interim PET scan results.

DATA COLLECTION AND ANALYSIS

We developed a data extraction form according to the Checklist for Critical Appraisal and Data Extraction for Systematic Reviews of Prediction Modelling Studies (CHARMS). Two teams of two review authors independently screened the studies, extracted data on overall survival (OS), progression-free survival (PFS) and PET-associated adverse events (AEs), assessed risk of bias (per outcome) according to the Quality in Prognosis Studies (QUIPS) tool, and assessed the certainty of the evidence (GRADE). We contacted investigators to obtain missing information and data.

MAIN RESULTS

Our literature search yielded 11,277 results. In total, we included 23 studies (99 references) with 7335 newly-diagnosed individuals with classic HL (all stages). Participants in 16 studies underwent (interim) PET combined with computed tomography (PET-CT), compared to PET only in the remaining seven studies. The standard chemotherapy regimen included ABVD (16) studies, compared to BEACOPP or other regimens (seven studies). Most studies (N = 21) conducted interim PET scans after two cycles (PET2) of chemotherapy, although PET1, PET3 and PET4 were also reported in some studies. In the meta-analyses, we used PET2 data if available as we wanted to ensure homogeneity between studies. In most studies interim PET scan results were evaluated according to the Deauville 5-point scale (N = 12). Eight studies were not included in meta-analyses due to missing information and/or data; results were reported narratively. For the remaining studies, we pooled the unadjusted hazard ratio (HR). The timing of the outcome measurement was after two or three years (the median follow-up time ranged from 22 to 65 months) in the pooled studies. Eight studies explored the independent prognostic ability of interim PET by adjusting for other established prognostic factors (e.g. disease stage, B symptoms). We did not pool the results because the multivariable analyses adjusted for a different set of factors in each study. Overall survival Twelve (out of 23) studies reported OS. Six of these were assessed as low risk of bias in all of the first four domains of QUIPS (study participation, study attrition, prognostic factor measurement and outcome measurement). The other six studies were assessed as unclear, moderate or high risk of bias in at least one of these four domains. Four studies were assessed as low risk, and eight studies as high risk of bias for the domain other prognostic factors (covariates). Nine studies were assessed as low risk, and three studies as high risk of bias for the domain 'statistical analysis and reporting'. We pooled nine studies with 1802 participants. Participants with HL who have a negative interim PET scan result probably have a large advantage in OS compared to those with a positive interim PET scan result (unadjusted HR 5.09, 95% confidence interval (CI) 2.64 to 9.81, I² = 44%, moderate-certainty evidence). In absolute values, this means that 900 out of 1000 participants with a negative interim PET scan result will probably survive longer than three years compared to 585 (95% CI 356 to 757) out of 1000 participants with a positive result. Adjusted results from two studies also indicate an independent prognostic value of interim PET scan results (moderate-certainty evidence). Progression-free survival Twenty-one studies reported PFS. Eleven out of 21 were assessed as low risk of bias in the first four domains. The remaining were assessed as unclear, moderate or high risk of bias in at least one of the four domains. Eleven studies were assessed as low risk, and ten studies as high risk of bias for the domain other prognostic factors (covariates). Eight studies were assessed as high risk, thirteen as low risk of bias for statistical analysis and reporting. We pooled 14 studies with 2079 participants. Participants who have a negative interim PET scan result may have an advantage in PFS compared to those with a positive interim PET scan result, but the evidence is very uncertain (unadjusted HR 4.90, 95% CI 3.47 to 6.90, I² = 45%, very low-certainty evidence). This means that 850 out of 1000 participants with a negative interim PET scan result may be progression-free longer than three years compared to 451 (95% CI 326 to 569) out of 1000 participants with a positive result. Adjusted results (not pooled) from eight studies also indicate that there may be an independent prognostic value of interim PET scan results (low-certainty evidence). PET-associated adverse events No study measured PET-associated AEs.

AUTHORS' CONCLUSIONS

This review provides moderate-certainty evidence that interim PET scan results predict OS, and very low-certainty evidence that interim PET scan results predict progression-free survival in treated individuals with HL. This evidence is primarily based on unadjusted data. More studies are needed to test the adjusted prognostic ability of interim PET against established prognostic factors.

Low concentrations of FA exhibits the Hormesis effect by affecting cell division and the Warburg effect

Formaldehyde (FA), a ubiquitous indoor environmental pollutant, has been classified as a carcinogen. There are many studies showed that low levels of FA could promote cell proliferation, however, little is known about the signal pathways. To determine the potential molecular mechanisms, human chronic myeloid leukemia cells (K562 cells) and human bronchial epithelial cells (16HBE cells) were exposed to different concentrations of FA. The data showed that FA at 0-125 μM or 0-60 μM promoted the proliferation of K562 cells or 16HBE cells respectively, indicating that FA did have the Hormesis effect. FA at 75 μM (K562 cells) and 40 μM (16HBE cells) significantly promoted cell proliferation, increased intracellular reactive oxygen species (ROS) levels, and decreased glutathione (GSH) content. At the same time, FA treatment induced a marked increase in the key molecules of cell division like CyclinD-cdk4 and E2F1. In addition, pyruvate kinase isozyme M2 (PKM2), glucose, glucose transporter 1 (GLUT1), lactic acid and lactate dehydrogenase A (LDHA) content in the Warburg effect were increased. Administering Vitamin E (VE), significantly disrupted cell division and disturbed the Warburg effect, effectively indicating the decrease of cell activity. Conclusively, these findings suggested that low concentrations of FA could promote cell proliferation by accelerating cell division process or enhancing the Warburg effect to embody the Hormesis effect.

Interim PET-results for prognosis in adults with Hodgkin lymphoma: a systematic review and meta-analysis of prognostic factor studies

BACKGROUND

Hodgkin lymphoma (HL) is one of the most common haematological malignancies in young adults and, with cure rates of 90%, has become curable for the majority of individuals. Positron emission tomography (PET) is an imaging tool used to monitor a tumour's metabolic activity, stage and progression. Interim PET during chemotherapy has been posited as a prognostic factor in individuals with HL to distinguish between those with a poor prognosis and those with a better prognosis. This distinction is important to inform decision-making on the clinical pathway of individuals with HL.

OBJECTIVES

To determine whether in previously untreated adults with HL receiving first-line therapy, interim PET scan results can distinguish between those with a poor prognosis and those with a better prognosis, and thereby predict survival outcomes in each group.

SEARCH METHODS

We searched MEDLINE, Embase, CENTRAL and conference proceedings up until April 2019. We also searched one trial registry (ClinicalTrials.gov).

SELECTION CRITERIA

We included retrospective and prospective studies evaluating interim PET scans in a minimum of 10 individuals with HL (all stages) undergoing first-line therapy. Interim PET was defined as conducted during therapy (after one, two, three or four treatment cycles). The minimum follow-up period was at least 12 months. We excluded studies if the trial design allowed treatment modification based on the interim PET scan results.

DATA COLLECTION AND ANALYSIS

We developed a data extraction form according to the Checklist for Critical Appraisal and Data Extraction for Systematic Reviews of Prediction Modelling Studies (CHARMS). Two teams of two review authors independently screened the studies, extracted data on overall survival (OS), progression-free survival (PFS) and PET-associated adverse events (AEs), assessed risk of bias (per outcome) according to the Quality in Prognosis Studies (QUIPS) tool, and assessed the certainty of the evidence (GRADE). We contacted investigators to obtain missing information and data.

MAIN RESULTS

Our literature search yielded 11,277 results. In total, we included 23 studies (99 references) with 7335 newly-diagnosed individuals with classic HL (all stages).Participants in 16 studies underwent (interim) PET combined with computed tomography (PET-CT), compared to PET only in the remaining seven studies. The standard chemotherapy regimen included ABVD (16) studies, compared to BEACOPP or other regimens (seven studies). Most studies (N = 21) conducted interim PET scans after two cycles (PET2) of chemotherapy, although PET1, PET3 and PET4 were also reported in some studies. In the meta-analyses, we used PET2 data if available as we wanted to ensure homogeneity between studies. In most studies interim PET scan results were evaluated according to the Deauville 5-point scale (N = 12).Eight studies were not included in meta-analyses due to missing information and/or data; results were reported narratively. For the remaining studies, we pooled the unadjusted hazard ratio (HR). The timing of the outcome measurement was after two or three years (the median follow-up time ranged from 22 to 65 months) in the pooled studies.Eight studies explored the independent prognostic ability of interim PET by adjusting for other established prognostic factors (e.g. disease stage, B symptoms). We did not pool the results because the multivariable analyses adjusted for a different set of factors in each study.Overall survivalTwelve (out of 23) studies reported OS. Six of these were assessed as low risk of bias in all of the first four domains of QUIPS (study participation, study attrition, prognostic factor measurement and outcome measurement). The other six studies were assessed as unclear, moderate or high risk of bias in at least one of these four domains. Nine studies were assessed as high risk, and three studies as moderate risk of bias for the domain study confounding. Eight studies were assessed as low risk, and four studies as high risk of bias for the domain statistical analysis and reporting.We pooled nine studies with 1802 participants. Participants with HL who have a negative interim PET scan result probably have a large advantage in OS compared to those with a positive interim PET scan result (unadjusted HR 5.09, 95% confidence interval (CI) 2.64 to 9.81, I² = 44%, moderate-certainty evidence). In absolute values, this means that 900 out of 1000 participants with a negative interim PET scan result will probably survive longer than three years compared to 585 (95% CI 356 to 757) out of 1000 participants with a positive result.Adjusted results from two studies also indicate an independent prognostic value of interim PET scan results (moderate-certainty evidence).Progression-free survival Twenty-one studies reported PFS. Eleven out of 21 were assessed as low risk of bias in the first four domains. The remaining were assessed as unclear, moderate or high risk of bias in at least one of the four domains. Eleven studies were assessed as high risk, nine studies as moderate risk and one study as low risk of bias for study confounding. Eight studies were assessed as high risk, three as moderate risk and nine as low risk of bias for statistical analysis and reporting.We pooled 14 studies with 2079 participants. Participants who have a negative interim PET scan result may have an advantage in PFS compared to those with a positive interim PET scan result, but the evidence is very uncertain (unadjusted HR 4.90, 95% CI 3.47 to 6.90, I² = 45%, very low-certainty evidence). This means that 850 out of 1000 participants with a negative interim PET scan result may be progression-free longer than three years compared to 451 (95% CI 326 to 569) out of 1000 participants with a positive result.Adjusted results (not pooled) from eight studies also indicate that there may be an independent prognostic value of interim PET scan results (low-certainty evidence).PET-associated adverse eventsNo study measured PET-associated AEs.

AUTHORS' CONCLUSIONS

This review provides moderate-certainty evidence that interim PET scan results predict OS, and very low-certainty evidence that interim PET scan results predict progression-free survival in treated individuals with HL. This evidence is primarily based on unadjusted data. More studies are needed to test the adjusted prognostic ability of interim PET against established prognostic factors.

Tumor Metabolism as a Regulator of Tumor-Host Interactions in the B-Cell Lymphoma Microenvironment-Fueling Progression and Novel Brakes for Therapy

Tumor metabolism and its specific alterations have become an integral part of understanding functional alterations leading to malignant transformation and maintaining cancer progression. Here, we review the metabolic changes in B-cell neoplasia, focusing on the effects of tumor metabolism on the tumor microenvironment (TME). Particularly, innate and adaptive immune responses are regulated by metabolites in the TME such as lactate. With steadily increasing therapeutic options implicating or utilizing the TME, it has become essential to address the metabolic alterations in B-cell malignancy for therapeutic approaches. In this review, we discuss metabolic alterations of B-cell lymphoma, consequences for currently used therapy regimens, and novel approaches specifically targeting metabolism in the TME.

Dihydroartemisinin suppresses glycolysis of LNCaP cells by inhibiting PI3K/AKT pathway and downregulating HIF-1α expression

AIMS

Dihydroartemisinin (DHA) exhibits potential anticancer activity. However, the biological functions of DHA in prostate cancer remain largely unexplored. In this study, we aim to investigate the anti-proliferative effect and glycolysis regulation of DHA on prostate cancer cell LNCaP.

MAIN METHODS

Cell proliferative activity and apoptosis inducing were detected. The gene expression was detected by mRNA microarray and results were analyzed by GO and KEGG pathway database. Expressions of glycolysis key enzymes and PI3K/AKT/HIF-1α were detected by Western blot.

KEY FINDINGS

Results indicated that DHA could inhibit the LNCaP cell proliferation considerably and induce cell apoptosis. mRNA microarray showed 1293 genes were upregulated and 2322 genes were downregulated. GO and KEGG enrichment analysis suggested that glycolysis pathway was correlated with DHA inhibited the proliferation on the LNCaP cell. Western blot results showed that DHA can decrease GLUT1 and regulatory enzymes of glycolytic pathway expression probably by suppressing the activity of the intracellular Akt/mTOR and HIF-1 α.

SIGNIFICANCE

Experimental validation results indicate that DHA treatment can inhibit the LNCaP cell proliferation and induce apoptosis, which may be related to glycolysis inhibition.

18F-Fluorodeoxyglucose positron emission tomography computed tomography detection threshold in follicular lymphoma: A case report

RATIONALE

Follicular Lymphoma in situ is generally identified as reactive follicular hyperplasia in which some of the hyperplastic germinal centers are colonized by few lymphoma cells. These cells can be detected through their strong 18F-Fluorodeoxyglucose avidity.

PATIENT CONCERNS

We report the case of a 70 year-old patient with arthralgia, weight loss and chronic fever over two months. A paraneoplastic polymyalgia rheumatica was initially suspected on abnormal 18F fluoro-deoxyglucose positron emission tomography (PET) pictures in two inguinal lymph nodes with a standardized uptake value at 8.6 and 5.8.

DIAGNOSES

The PET lymph nodes were removed and histological examination revealed subtle lymph nodes infiltration by follicular lymphoma in situ. The absolute number of the follicular lymphoma cells determined using virtual imaging and 3D reconstruction appeared very low with a total tumor cell volume estimated at around 0.026 mm for one lymph node and 0.041 mm for the other.

INTERVENTIONS

The patient has been treated by corticotherapy alone.

OUTCOMES

A long-time follow-up should be highly suggested for this patient to avoid any risk of clinical progression to follicular lymphoma.

LESSONS

Our findings show that low amounts of follicular lymphoma cells in reactive germinal center may reach a threshold of hypermetabolism detectable with positron emission tomography imaging, suggesting that tumor microenvironment also accounts for such as strong fluoro-deoxyglucose avidity. Thus, a systematic immunohistochemistry with anti-BCL2 antibodies should be performed on PET positive lymph node with apparent normal morphological features.

Whole-Body Diffusion-weighted MR Imaging of Iron Deposits in Hodgkin, Follicular, and Diffuse Large B-Cell Lymphoma

Purpose To analyze the frequency and distribution of low-signal-intensity regions (LSIRs) in lymphoma lesions and to compare these to fluorodeoxyglucose (FDG) uptake and biologic markers of inflammation. Materials and Methods The authors analyzed 61 untreated patients with a bulky lymphoma (at least one tumor mass ≥7 cm in diameter). When a LSIR within tumor lesions was detected on diffusion-weighted images obtained with a b value of 50 sec/mm², a T2-weighted gradient-echo (GRE) sequence was performed and calcifications were searched for with computed tomography (CT). In two patients, Perls staining was performed on tissue samples from the LSIR. LSIRs were compared with biologic inflammatory parameters and baseline FDG positon emission tomography (PET)/CT parameters (maximum standardized uptake value [SUV_max], total metabolic tumor volume [TMTV]). Results LSIRs were detected in 22 patients and corresponded to signal void on GRE images; one LSIR was due to calcifications, and three LSIRS were due to a recent biopsy. In 18 patients, LSIRs appeared to be related to focal iron deposits; this was proven with Perls staining in two patients. The LSIRs presumed to be due to iron deposits were found mostly in patients with aggressive lymphoma (nine of 26 patients with Hodgkin lymphoma and eight of 20 patients with diffuse large B-cell lymphoma vs one of 15 patients with follicular lymphoma; P = .047) and with advanced stage disease (15 of 18 patients). LSIRS were observed in spleen (n = 14), liver (n = 3), and nodal (n = 8) lesions and corresponded to foci FDG uptake, with mean SUV_max of 9.8, 6.7, and 16.2, respectively. These patients had significantly higher serum levels of C-reactive protein, α₁-globulin, and α₂-globulin and more frequently had microcytic anemia than those without such deposits (P = .0072, P = .003, P = .0068, and P < .0001, respectively). They also had a significantly higher TMTV (P = .0055) and higher levels of spleen involvement (P < .0001). Conclusion LSIRs due to focal iron deposits are detected in lymphoma lesions and are associated with a more pronounced biologic inflammatory syndrome. ^© RSNA, 2017 Online supplemental material is available for this article.

LMP1-mediated glycolysis induces myeloid-derived suppressor cell expansion in nasopharyngeal carcinoma

Myeloid-derived suppressor cells (MDSCs) are expanded in tumor microenvironments, including that of Epstein–Barr virus (EBV)-associated nasopharyngeal carcinoma (NPC). The link between MDSC expansion and EBV infection in NPC is unclear. Here, we show that EBV latent membrane protein 1 (LMP1) promotes MDSC expansion in the tumor microenvironment by promoting extra-mitochondrial glycolysis in malignant cells, which is a scenario for immune escape initially suggested by the frequent, concomitant detection of abundant LMP1, glucose transporter 1 (GLUT1) and CD33⁺ MDSCs in tumor sections. The full process has been reconstituted in vitro. LMP1 promotes the expression of multiple glycolytic genes, including GLUT1. This metabolic reprogramming results in increased expression of the Nod-like receptor family protein 3 (NLRP3) inflammasome, COX-2 and P-p65 and, consequently, increased production of IL-1β, IL-6 and GM-CSF. Finally, these changes in the environment of malignant cells result in enhanced NPC-derived MDSC induction. One key step is the physical interaction of LMP1 with GLUT1 to stabilize the GLUT1 protein by blocking its K48-ubiquitination and p62-dependent autolysosomal degradation. This work indicates that LMP1-mediated glycolysis regulates IL-1β, IL-6 and GM-CSF production through the NLRP3 inflammasome, COX-2 and P-p65 signaling pathways to enhance tumor-associated MDSC expansion, which leads to tumor immunosuppression in NPC.

The expression of the Epstein-Barr virus (EBV) oncogenic protein denoted latent membrane protein 1 (LMP1) varies in patients with NPC and is linked to tumorigenesis and tumor immunosuppression, but the molecular mechanism through which LMP1 leads to tumor immune escape remains unknown. Work to date suggests that the expansion of tumor-associated myeloid-derived suppressor cells (MDSCs) is the main cause of tumor immunosuppression such as that found in NPC. Here, we found that tumor LMP1 expression is correlated with glucose transporter 1 (GLUT1) levels, CD33⁺ MDSC number and unfavorable survival in patients with NPC. Based on the results of our in vitro analysis, LMP1 promotes GLUT1-dependent glycolysis in NPC cells, resulting in activation of the Nod-like receptor family protein 3 (NLRP3) inflammasome, COX-2 and P-p65 signaling pathways and subsequently increased IL-1β, IL-6 and GM-CSF production. Importantly, LMP1 interacts with GLUT1 to stabilize the GLUT1 protein by disrupting its K48-linked ubiquitination and autolysosomal degradation in a p62-dependent manner and up-regulating the GLUT1 mRNA and protein levels by inducing p65 activation. Therefore, we determined that GLUT1-dependent glycolysis is required for tumor-induced MDSC differentiation and that this process is associated with LMP1 expression. Based on our findings, LMP1-mediated glycolysis is a key process involved in controlling tumor immunosuppression and directly contributes to oncogenesis.

GLUT1 as a Prognostic Factor for Classical Hodgkin's Lymphoma: Correlation with PD-L1 and PD-L2 Expression

Background

Glucose transporter type 1 (GLUT1) expression is linked to glucose metabolism and tissue hypoxia. A recent study reported that GLUT1 was significantly associated with programmed death ligand 1 (PD-L1) as a therapeutic target in relapsed or refractory classical Hodgkin’s lymphoma (cHL). The purpose of this study was to measure the expression of GLUT1 and assess its prognostic significance and potential relationships with PD-L1, programmed death ligand 2 (PD-L2), and programmed death-1 (PD-1) expressions in cHL.

Methods

Diagnostic tissues from 125 patients with cHL treated with doxorubicin, bleomycin, vinblastine, and dacarbazine were evaluated retrospectively via immunohistochemical analysis of GLUT1, PD-L1, PD-L2, and PD-1 expression.

Results

The median follow-up time was 4.83 years (range, 0.08 to 17.33 years). GLUT1, PD-L1, PD-L2, and PD-1 were expressed in 44.8%, 63.2%, 9.6%, and 13.6% of the specimens, respectively. Positive correlations were found between GLUT1 and PD-L1 expression (p = .004) and between GLUT1 and PD-L2 expression (p = .031). GLUT1 expression in Hodgkin/Reed-Sternberg (HRS) cells was not associated with overall survival or event-free survival (EFS) in the entire cohort (p = .299 and p = .143, respectively). A subgroup analysis according to the Ann Arbor stage illustrated that GLUT1 expression in HRS cells was associated with better EFS in advanced-stage disease (p = .029). A multivariate analysis identified GLUT1 as a marginally significant prognostic factor for EFS (p = .068).

Conclusions

This study suggests that GLUT1 expression is associated with better clinical outcomes in advanced-stage cHL and is significantly associated with PD-L1 and PD-L2 expressions.

The PI3K pathway in B cell metabolism

B cell growth and proliferation is tightly regulated by signaling through the B cell receptor and by other membrane bound receptors responding to different cytokines. The PI3K signaling pathway has been shown to play a crucial role in B cell activation, differentiation and survival. Activated B cells undergo metabolic reprograming in response to changing energetic and biosynthetic demands. B cells also need to be able to coordinate metabolic activity and proliferation with nutrient availability. The PI3K signaling network has been implicated in regulating nutrient acquisition, utilization and biosynthesis, thus integrating receptor-mediated signaling with cell metabolism. In this review, we discuss the current knowledge about metabolic changes induced in activated B cells, strategies to adapt to metabolic stress and the role of PI3K signaling in these processes.

A Case Report of High 18F-FDG PET/CT Uptake in Progressive Transformation of the Germinal Centers

Progressive transformation of the germinal centers (PTGC) is a benign reaction pattern in lymph nodes. An association with Hodgkin disease (HD) has been reported and PTGC may precede, coexist, or present after the diagnosis of HD. This case report describes a patient who presented with unprovoked pulmonary embolism and subsequent investigations showed a solitary abdominal mass, which was subsequently proven to be PTGC. PTGC is usually avid on fluorine-18-labeled fluorodeoxyglucose positron emission tomography with computed tomography for attenuation correction and may be mistaken for neoplastic disease. Being a reactive etiology, the metabolic activity is generally low with a low maximum standardized uptake value (SUVmax), but in our case, the metabolic activity and corresponding SUVmax were relatively high making the diagnosis difficult, as most clinicians would consider a high metabolically active process more likely malignant. Recognition of PTGC is important, as it is not a malignant process. Owing to its reported associations, however, patients with this diagnosis will likely require regular surveillance.

FDG PET/CT imaging as a biomarker in lymphoma

FDG PET/CT has changed the management of FDG-avid lymphoma and is now recommended as the imaging technique of choice for staging and restaging. The need for tailoring therapy to reduce toxicity in patients with a favourable outcome and for improving treatment in those with high-risk factors requires accurate diagnostic methods and a new prognostic algorithm to identify different risk categories. New drugs are used in relapsed/refractory patients. The role of FDG PET/CT as a biomarker in this context is summarized in this review. New trends in FDG metabolic imaging in lymphoma are addressed including metabolic tumour volume measurement at staging and integrative PET which combines PET data with clinical and molecular markers or other imaging techniques. The quantitative approach for response assessment which is under investigation and is used in large ongoing trials is compared with visual criteria. The place of FDG in the era of targeted therapy is discussed.

[Nodular lymphocyte-predominant Hodgkin's lymphoma and differential diagnoses]

Nodular lymphocyte-predominant Hodgkin's lymphoma (NLPHL) is a rare subtype of Hodgkin's lymphoma. The histological patterns of NLPHL variants are characterized by different localizations of the tumor cells, intranodular and perinodular and by the varying composition of the microenvironment. T-cell/histiocyte-rich B-cell lymphoma may be the result of an aggressive transformation of NLPHL. Classical lymphocyte-rich Hodgkin's lymphoma can usually be clearly distinguished from NLPHL by the immunophenotype of the tumor cells. Further differential diagnoses include follicular lymphoma and the follicular variant of peripheral T-cell lymphoma. Angioimmunoblastic T-cell lymphoma with CD20-positive blasts represents a differential diagnosis to the diffuse variants of NLPHL.