The Broad Spectrum HDAC Inhibitor PCI-24781 Induces Caspase- and ROS-Dependent Apoptosis and is Synergistic with Bortezomib in Lymphoma

We investigated the cytotoxicity and biology of the novel broad-spectrum hydroxamic acid-based histone deacetylase inhibitor (HDACi), PCI-24781. PCI-24781 was studied alone and combined with bortezomib in Hodgkin lymphoma (L428) and non-Hodgkin's lymphoma cell lines (Ramos, HF1, SUDHL4). PCI-24781 induced dose-dependent apoptosis that was associated with prominent G0/G1 arrest, decreased S-phase, increased p21 protein expression, and production of reactive oxygen species (ROS). Furthermore, PCI-24781-induced apoptosis was shown to be ROS- and caspase-dependent. Combined PCI-24781 and bortezomib exposure resulted in strong synergistic apoptosis in all cell lines (combination indices 0.19-0.6). Furthermore, compared to either agent alone, PCI-24781/bortezomib resulted in increased caspase cleavage, mitochondrial depolarization, and histone hyperacetylation. Microarray analyses showed that PCI-24781 alone significantly downregulated several antioxidant genes, proteasome components, and NF-kappaB pathway genes, effects which were enhanced further with bortezomib. RT-PCR confirmed downregulation of NF-kappaB targets NF-kappaB1 (p105), c-Myc, and IkappaB-kinase subunits, while gel-shift showed decreased NF-kappaB DNA-binding activity. Taken together, these results suggest that increased oxidative stress and NF-kappaB inhibition, leading to caspase activation and apoptosis, are likely responsible for the activity of PCI-24781 as well as the observed synergy with bortezomib. These data indicate that PCI-24781 has potential therapeutic value in lymphoma as a single-agent and combined with bortezomib

Clinicopathologic consensus study of gray zone lymphoma with features intermediate between DLBCL and classical HL

Gray zone lymphoma (GZL) is described as sharing features with classical Hodgkin lymphoma (cHL) and diffuse large B-cell lymphoma (DLBCL). However, there remains complexity in establishing diagnosis, delineating prognosis, and determining optimum therapy. Sixty-eight cases diagnosed as GZL across 15 North American academic centers were evaluated by central pathology review to achieve consensus. Of these, only 26 (38%) were confirmed as GZL. Morphology was critical to GZL consensus diagnosis (eg, tumor cell richness); immunohistochemistry showed universal B-cell derivation, frequent CD30 expression, and rare Epstein-Barr virus (EBV) positivity (CD20(+), 83%; PAX5(+), 100%; BCL6(+), 20%; MUM1(+), 100%; CD30(+), 92%; EBV(+), 4%). Forty-two cases were reclassified: nodular sclerosis (NS) cHL, n = 27 (including n = 10 NS grade 2); lymphocyte predominant HL, n = 4; DLBCL, n = 4; EBV(+) DLBCL, n = 3; primary mediastinal large BCL n = 2; lymphocyte-rich cHL and BCL-not otherwise specified, n = 1 each. GZL consensus-confirmed vs reclassified cases, respectively, more often had mediastinal disease (69% vs 41%; P = .038) and less likely more than 1 extranodal site (0% vs 25%; P = .019). With a 44-month median follow-up, 3-year progression-free survival (PFS) and overall survival for patients with confirmed GZL were 39% and 95%, respectively, vs 58% and 85%, respectively, for reclassified cases (P = .19 and P = .15, respectively). Interestingly, NS grade 2 reclassified patients had similar PFS as GZL consensus-confirmed cases. For prognostication of GZL cases, hypoalbuminemia was a negative factor (3-year PFS, 12% vs 64%; P = .01), whereas frontline cyclophosphamide, doxorubicin, vincristine, and prednisone +/- rituximab (CHOP+/-R) was associated with improved 3-year PFS (70% vs 20%; P = .03); both factors remained significant on multivariate analysis. Altogether, accurate diagnosis of GZL remains challenging, and improved therapeutic strategies are needed

Allogeneic hematopoietic cell transplantation as curative therapy for patients with non-Hodgkin lymphoma: Increasingly successful application to older patients

AbstractNon-Hodgkin lymphoma (NHL) constitutes a collection of lymphoproliferative disorders with widely varying biological, histological, and clinical features. For the B cell NHLs, great progress has been made due to the addition of monoclonal antibodies and, more recently, other novel agents including B cell receptor signaling inhibitors, immunomodulatory agents, and proteasome inhibitors. Autologous hematopoietic cell transplantation (auto-HCT) offers the promise of cure or prolonged remission in some NHL patients. For some patients, however, auto-HCT may never be a viable option, whereas in others, the disease may progress despite auto-HCT. In those settings, allogeneic HCT (allo-HCT) offers the potential for cure. Over the past 10 to 15 years, considerable progress has been made in the implementation of allo-HCT, such that this approach now is a highly effective therapy for patients up to (and even beyond) age 75 years. Recent advances in conventional lymphoma therapy, peritransplantation supportive care, patient selection, and donor selection (including the use of alternative hematopoietic cell donors), has allowed broader application of allo-HCT to patients with NHL. As a result, an ever-increasing number of NHL patients over age 60 to 65 years stand to benefit from allo-HCT. In this review, we present data in support of the use of allo-HCT for patients with diffuse large B cell lymphoma, follicular lymphoma, and mantle cell lymphoma. These histologies account for a large majority of allo-HCTs performed for patients over age 60 in the United States. Where possible, we highlight available data in older patients. This body of literature strongly supports the concept that allo-HCT should be offered to fit patients well beyond age 65 and, accordingly, that this treatment should be covered by their insurance carriers

The immune checkpoint molecules PD-1, PD-L1, TIM-3 and LAG-3 in diffuse large B-cell lymphoma

Signaling through immune checkpoint receptors may lead to T-cell exhaustion and function as immune escape mechanisms in cancer. For diffuse large B-cell lymphoma (DLBCL), the mechanistic and prognostic importance of these markers on tumor cells and the tumor microenvironment remains unclear. We determined the immunohistochemical expression of PD-1, PD-L1, TIM-3, and LAG-3 on tumor cells and on tumor infiltrating lymphocytes (TILs) among 123 DLBCL patients. TIM-3 showed positive staining on tumor cells in 39% of DLBCL cases and PD-L1 expression was noted in 15% of cases. Both PD-1 and LAG-3 were positive on tumor cells in a minority of DLBCL cases (8.3% and 7.5%, respectively), but were more widely expressed on TILs in a correlated manner. With median follow-up of 44 months (n = 70, range 5-85), 4-year progression-free survival (PFS) and overall survival (OS) rates were significantly inferior among DLBCL patients with high vs low/negative TIM-3 expression (PFS: 23% [95% CI 7% to 46%] vs 60% [95% CI 43% to 74%], respectively, P = 0.008; OS: 30% [95% CI 10% to 53%] vs 74% [95% CI 58% to 85%], respectively, P = 0.006). Differences in OS remained significant when controlling for International Prognostic Index in Cox regression analyses (HR 3.49 [95% CI 1.40-6.15], P = 0.007). In addition, we observed that co-culture of DLBCL cell lines with primed T cells in the presence of anti-LAG-3 and anti-TIM-3 induced potent dose-dependent increases in in vitro cell death via AcellaTox and IL-2 ELISA assays, suggesting potent anti-tumor activity of these compounds

Inhibition of Bromodomain Proteins in Treatment of Diffuse Large B-cell Lymphoma

Only ~50% of patients with diffuse large B-cell lymphoma (DLBCL), the most common and aggressive subtype of non-Hodgkin’s lymphoma, enter long-term remission after standard chemotherapy, and patients who do not respond to treatment have few options. Therefore, there is a critical need for effective and targeted therapeutics for DLBCL. Recent studies highlight the incidence of increased c-MYC protein in DLBCL and the correlation between high levels of c-MYC and poor survival prognosis of DLBCL patients, suggesting that c-MYC is a compelling therapeutic target for DLBCL therapy. The small molecule JQ1 suppresses c-MYC expression through inhibition of the BET family of bromodomain proteins. We show that JQ1 efficiently inhibited cell proliferation of human DLBCL cells regardless of their molecular subtypes, suggesting a broad effect of JQ1 in DLBCL. After JQ1 treatment, initial G1 arrest in DLBCL cells was followed by either apoptosis or senescence. In DLBCL cells treated with JQ1, we found that c-MYC expression was suppressed in the context of the natural, chromosomally-translocated or an amplified gene locus. Furthermore, JQ1 treatment significantly suppressed growth of DLBCL cells engrafted subcutaneously and improved survival of mice engrafted with DLBCL cells intraperitoneally. These results demonstrate that inhibition of the BET family of bromodomain proteins, and consequently c-MYC, has the potential clinical utility in DLBCL treatment

PD-L1 expression in EBV-negative diffuse large B-cell lymphoma: clinicopathologic features and prognostic implications

Programmed cell death ligand 1 (PD-L1) is a cell surface glycoprotein that regulates the cellular immune response and serves as a targetable immune checkpoint molecule. PD-L1 is expressed on tumor cells and the immune microenvironment of several human malignancies, including a subset of aggressive lymphomas. We sought to investigate further the clinical and pathologic features of EBV-negative diffuse large B-cell lymphoma (DLBCL) cases that express PD-L1. Immunohistochemical staining using an anti-PD-L1 monoclonal antibody was performed on DLBCL cases from 86 patients. These patients received standard chemotherapy treatment and were followed for up to 175 months. Overall, 14 cases (16%) were considered positive for PD-L1 in tumor cells. In comparison with PD-L1 negative cases, PD-L1 positive cases had a higher rate of non-GCB type (71% vs. 30%, P=0.0060), and higher Ann Arbor stage (II-IV) (100% vs. 73%, P=0.0327). No significant differences were seen in the immunohistochemical expression of BCL2, MYC, or Ki67. Patients with tumors expressing PD-L1 demonstrated inferior overall survival (OS) upon long term follow up (P=0.0447). Both age/sex-adjusted and multivariate analyses identified PD-L1 as an independent predictor for OS (P=0.0101 and P=0.0424). There was no significant difference, however, in terms of remission rates after first treatment, relapse rates, and progression free survival between the groups. Identification of DLBCL cases that express PD-L1 may serve to select a subset of patients that could further benefit from targeted immunotherapy

Socioeconomic inequalities in treatment and relative survival among patients with diffuse large B-cell lymphoma: a Hong Kong population-based study.

The influence of socioeconomic status (SES) on access to standard chemotherapy and/or monoclonal antibody therapy, and associated secular trends, relative survival, and excess mortality, among diffuse large B-cell lymphoma (DLBCL) patients is not clear. We conducted a Hong Kong population-based cohort study and identified adult patients with histologically diagnosed DLBCL between 2000 and 2018. We examined the association of SES levels with the odds and the secular trends of receipt of chemotherapy and/or rituximab. Additionally, we estimated the long-term relative survival by SES utilizing Hong Kong life tables. Among 4017 patients with DLBCL, 2363 (58.8%) patients received both chemotherapy and rituximab and 740 (18.4%) patients received chemotherapy alone, while 1612 (40.1%) and 914 (22.8%) patients received no rituximab or chemotherapy, respectively. On multivariable analysis, low SES was associated with lesser use of chemotherapy (odd ratio [OR] 0.44; 95% CI 0.34-0.57) and rituximab (OR 0.41; 95% CI 0.32-0.52). The socioeconomic disparity for either treatment showed no secular trend of change. Additionally, patients with low SES showed increased excess mortality, with a hazard ratio of 2.34 (95% CI 1.67-3.28). Improving survival outcomes for patients with DLBCL requires provision of best available medical care and securing access to treatment regardless of patients' SES

A Multicenter Phase 2 Study Incorporating High-Dose Rituximab into the CODOX-M/IVAC Regimen for Untreated Burkitt’s Lymphoma (BL): Examination of Correlative Serum and CSF Rituximab Levels

Background: Two-year survival rates for adult BL remain Methods: Twenty-five BL patients were enrolled. Patients had low-risk (LR) or high-risk (HR) disease; LR patients received 3 CODOX-M cycles, while HR had 4 alternating CODOX-M/IVAC cycles (Mead et al. Blood 2009). Rituximab (500mg/m2) was given x 2 doses each cycle. Correlative analyses of paired serum and CSF Rituximab levels were obtained for cycles 1+3 at 24+72 hours. Results: There were 20 HR and 5 LR patients and median age was 44 years (range, 23-70). 3 HR and 1 LR patient were HIV+, while 15% of HR patients had CNS disease. Additionally, 35% of HR patients had bulk \u3e10 cm and 40% had bone marrow involvement. Myelosuppression and mucositis appeared comparable with prior CODOX-M/IVAC data. The overall remission rate after 2 cycles was 100% with 67% complete remission. At 34-month median follow-up, 2-year PFS and OS rates for all patients were 86% and 86%, respectively (LR 2-year PFS and OS: both 100%; HR 2-year PFS and OS: both 82%). Further, the 2-year PFS and OS for HR, HIV-negative patients were 91% and 91%, respectively (disease-specific survival 100%). Two patients died from progressive disease (both HIV+ HR). The median serum and CSF rituximab levels for these patients were compared with patients without relapse (Table 1). Interestingly, cycle 1, 24-hour serum Rituximab levels were significantly higher among patients without relapse compared with the two patients who relapsed/died (P=0.042). Cycle 3, 24-hour Rituximab levels were of borderline significance (P=0.06). Conclusions: The integration of Rituximab into CODOX-M/IVAC was associated with excellent survival rates, especially for HIV-negative BL. Further investigation of the predictive value of serum Rituximab levels is warranted

A comparison of precipitation and filtration-based SARS-CoV-2 recovery methods and the influence of temperature, turbidity, and surfactant load in urban wastewater

Wastewater-based epidemiology (WBE) has become a complimentary surveillance tool during the SARS-CoV-2 pandemic. Viral concentration methods from wastewater are still being optimised and compared, whilst viral recovery under different wastewater characteristics and storage temperatures remains poorly understood. Using urban wastewater samples, we tested three viral concentration methods; polyethylene glycol precipitation (PEG), ammonium sulphate precipitation (AS), and CP select™ InnovaPrep® (IP) ultrafiltration. We found no major difference in SARS-CoV-2 and faecal indicator virus (crAssphage) recovery from wastewater samples (n = 46) using these methods, PEG slightly (albeit non-significantly), outperformed AS and IP for SARS-CoV-2 detection, as a higher genome copies per litre (gc/l) was recorded for a larger proportion of samples. Next generation sequencing of 8 paired samples revealed non-significant differences in the quality of data between AS and IP, though IP data quality was slightly better and less variable. A controlled experiment assessed the impact of wastewater suspended solids (turbidity; 0–400 NTU), surfactant load (0–200 mg/l), and storage temperature (5–20 °C) on viral recovery using the AS and IP methods. SARS-CoV-2 recoveries were >20% with AS and 0.05), whilst surfactant and storage temperature combined were significant negative correlates (p < 0.001 and p < 0.05, respectively). In conclusion, our results show that choice of methodology had small effect on viral recovery of SARS-CoV-2 and crAssphage in wastewater samples within this study. In contrast, sample turbidity, storage temperature, and surfactant load did affect viral recovery, highlighting the need for careful consideration of the viral concentration methodology used when working with wastewater samples