A Pilot Study Assessing Treatment Outcomes in Neovascular Glaucoma Using Ahmed Glaucoma Valve with and without Cyclophotocoagulation.

Purpose: The purpose of this retrospective pilot study was to examine the short-term effect of simultaneous Ahmed Glaucoma Valve implantation and cyclophotocoagulation on postoperative outcomes in patients with neovascular glaucoma. Methods and materials: Patient charts were selected for inclusion in this study if they carried a diagnosis of neovascular glaucoma and underwent Ahmed glaucoma valve implantation only, Ahmed glaucoma valve implantation with cyclophotocoagulation, or cyclophotocoagulation only. A total of 55 eyes of 54 patients were selected for data collection and analysis. Main outcome measures included 1-, 3-, and 6-month intraocular pressure and occurrence of the hypertensive phase. Other outcomes included visual acuity, surgical complication rate, and a number of 6-month postoperative ophthalmic medications. Results: A significantly lower intraocular pressure was seen in the group that received Ahmed glaucoma valve implantation + cyclophotocoagulation compared to the Ahmed glaucoma valve-only group at 3 and 6 months (p = 0.03 and <0.001, respectively). The difference in the occurrence of the hypertensive phase between the Ahmed glaucoma valve-only group and the Ahmed glaucoma valve + cyclophotocoagulation group approached but did not reach significance (p = 0.052). A significantly lower intraocular pressure was also seen in the cyclophotocoagulation-only group compared to the Ahmed glaucoma valve-only group at 3 months (p = 0.006). Conclusion: Simultaneous Ahmed glaucoma valve implantation and cyclophotocoagulation significantly lowered intraocular pressure at 3 and 6 months compared to Ahmed glaucoma valve implantation alone in patients with neovascular glaucoma. Clinical significance: Neovascular glaucoma is difficult to manage medically and surgically. When surgery is performed, intraocular pressure often remains elevated postoperatively despite aggressive medical management. This study examines a novel method to lower intraocular pressure after Ahmed glaucoma valve implantation in patients with neovascular glaucoma. How to cite this article: Ford RL, Knight ORJ, Klifto MR, et al. A Pilot Study Assessing Treatment Outcomes in Neovascular Glaucoma Using Ahmed Glaucoma Valve with and without Cyclophotocoagulation. J Curr Glaucoma Pract 2022;16(1):4-10.

Cerebrospinal fluid and ophthalmic disease.

PURPOSE OF REVIEW: The purpose of this review is to discuss the contemporary body of literature examining the relationship between cerebrospinal fluid (CSF) and ophthalmic disease. This review focuses on diseases that have a pathogenesis related to the translaminar pressure difference, defined as the pressure difference between the orbital subarachnoid space (OSAS) and the intraocular pressure. The diseases discussed include glaucoma, idiopathic intracranial hypertension, and spaceflight associated neuro-ocular syndrome. RECENT FINDINGS: The relationship between cerebrospinal and ophthalmic disease has been investigated for over 100 years. Recent research provides insight into the mechanisms that dictate CSF circulation in the OSAS and how alterations in these mechanism lead to disease. This review discusses these recent findings and their relationship to major ophthalmic diseases. SUMMARY: The recent findings provide insight into diseases that have pathogenic mechanisms that are not fully understood. This information will help physicians gain a clearer understanding of the relationship between CSF and ophthalmic disease and guide future research.

One-Year Front Versus Central and Paracentral Corneal Changes After Bowman Layer Transplantation for Keratoconus.

PURPOSE: To report the front corneal versus central and paracentral corneal changes after Bowman layer transplantation for keratoconus in a tertiary hospital in the United Kingdom. METHODS: Five eyes of 5 patients receiving Bowman layer transplant for advanced keratoconus in Royal Gwent Hospital (Newport, United Kingdom) were included. Preoperative and postoperative visual acuity; Kmax; Kmean, and corneal cylinder in the front cornea, 4.5 mm central, and 6 mm central; and corneal thickness were analyzed. RESULTS: Corneal flattening and reduction in corneal astigmatism was observed, more marked in the central and paracentral zone, allowing for improvement in best-corrected visual acuity with the aid of visual correction in 4 eyes. CONCLUSIONS: These results support previous data reporting Bowman layer transplantation as a useful strategy in the treatment of advanced keratoconus and suggest greater attention may be focused on central or paracentral corneal changes.

Determining the Value-Efficiency of Respiratory Care.

In order to determine, document, and communicate the value of respiratory therapists performing respiratory care procedures, the respiratory care profession needs to position itself to capture and report both time and value standards that can be applied in allocating respiratory care resources. To do this, we propose a new metric called value-efficiency. If we wish to use value-efficiency as a metric to justify respiratory care activities and support labor budgets, there are three key considerations: (1) What value does respiratory care add to the health care organization? (2) Are the interventions provided necessary and of clinical value? (3) What is the value of the respiratory therapist in the delivery of these services? Significant challenges are facing the respiratory care profession and a focus on value-efficiency is a direction the profession must pursue. This approach is a practical response to the increasing demands of payers, administrators, consultants, and patients.

Thyroid Disruptors: Extrathyroidal Sites of Chemical Action and Neurodevelopmental Outcome-An Examination Using Triclosan and Perfluorohexane Sulfonate.

Many xenobiotics are identified as potential thyroid disruptors due to their action to reduce circulating levels of thyroid hormone, most notably thyroxine (T4). Developmental neurotoxicity is a primary concern for thyroid disrupting chemicals yet correlating the impact of chemically induced changes in serum T4 to perturbed brain development remains elusive. A number of thyroid-specific neurodevelopmental assays have been proposed, based largely on the model thyroid hormone synthesis inhibitor propylthiouracil (PTU). This study examined whether thyroid disrupting chemicals acting distinct from synthesis inhibition would result in the same alterations in brain as expected with PTU. The perfluoroalkyl substance perfluorohexane sulfonate (50 mg/kg/day) and the antimicrobial Triclosan (300 mg/kg/day) were administered to pregnant rats from gestational day 6 to postnatal day (PN) 21, and a number of PTU-defined assays for neurotoxicity evaluated. Both chemicals reduced serum T4 but did not increase thyroid stimulating hormone. Both chemicals increased expression of hepatic metabolism genes, while thyroid hormone-responsive genes in the liver, thyroid gland, and brain were largely unchanged. Brain tissue T4 was reduced in newborns, but despite persistent T4 reductions in serum, had recovered in the PN6 pup brain. Neither treatment resulted in a low dose PTU-like phenotype in either brain morphology or neurobehavior, raising questions for the interpretation of serum biomarkers in regulatory toxicology. They further suggest that reliance on serum hormones as prescriptive of specific neurodevelopmental outcomes may be too simplistic and to understand thyroid-mediated neurotoxicity we must expand our thinking beyond that which follows thyroid hormone synthesis inhibition.

Chronic Kidney Disease as a Predictor of Postoperative Choroidal Effusions After Glaucoma Surgery.

PRCIS: Patients with chronic kidney disease (CKD) are at increased risk for choroidal effusion development following glaucoma surgery. PURPOSE: Choroidal effusion is a postoperative complication of glaucoma surgery that results from a transudative fluid collection in the suprachoroidal space. Kidney disease alters bodily fluid dynamics through a variety of mechanisms. The relationship between CKD and choroidal effusion following glaucoma surgery has not previously been studied. The purpose of this study was to determine the relationship between CKD and choroidal effusion development after glaucoma surgery. PATIENTS AND METHODS: This retrospective cohort study consisted of 86 eyes from 86 patients who received glaucoma filtering surgery or transscleral cyclophotocoagulation within the study timeframe. Forty-three patients had CKD, and 43 patients did not have kidney disease. The main outcome of this study was the development of choroidal effusion measured by the Pearson χ2 test and multivariate analysis using a binomial regression with a log link. RESULTS: Ten patients (23.3%) in the CKD group developed choroidal effusion, while 2 patients (4.7%) in the no-kidney disease group developed choroidal effusion (relative risk, 5.0; 95% confidence interval: 1.16-21.5; P=0.013). The association between CKD and choroidal effusion showed mixed results in the multivariate analysis, with some analyses showing a significant association and others showing no significant association. CONCLUSIONS: In both the univariate and multivariate analyses, CKD was found to be significantly associated with choroidal effusion after glaucoma surgery.

A transient window of hypothyroidism alters neural progenitor cells and results in abnormal brain development.

Cortical heterotopias are clusters of ectopic neurons in the brain and are associated with neurodevelopmental disorders like epilepsy and learning disabilities. We have previously characterized the robust penetrance of a heterotopia in a rat model, induced by thyroid hormone (TH) disruption during gestation. However, the specific mechanism by which maternal TH insufficiency results in this birth defect remains unknown. Here we first determined the developmental window susceptible to endocrine disruption and describe a cellular mechanism responsible for heterotopia formation. We show that five days of maternal goitrogen treatment (10 ppm propylthiouracil) during the perinatal period (GD19-PN2) induces a periventricular heterotopia in 100% of the offspring. Beginning in the early postnatal brain, neurons begin to aggregate near the ventricles of treated animals. In parallel, transcriptional and architectural changes of this region were observed including decreased Sonic hedgehog (Shh) expression, abnormal cell adhesion, and altered radial glia morphology. As the ventricular epithelium is juxtaposed to two sources of brain THs, the cerebrospinal fluid and vasculature, this progenitor niche may be especially susceptible to TH disruption. This work highlights the spatiotemporal vulnerabilities of the developing brain and demonstrates that a transient period of TH perturbation is sufficient to induce a congenital abnormality.

Analysis of a volumetric-modulated arc therapy (VMAT) single phase prostate template as a class solution.

AIM: To assess a class solution template for volumetric-modulated arc therapy (VMAT) for prostate cancer using plan analysis software. BACKGROUND: VMAT is a development of intensity-modulated radiotherapy (IMRT) with potential advantages for the delivery of radiotherapy (RT) in prostate cancer. Class solutions are increasingly used for facilitating RT planning. Plan analysis software provides an objective tool for evaluating class solutions. MATERIALS AND METHODS: The class solution for VMAT was based on the current static field IMRT template. The plans of 77 prostate cancer patients were evaluated using a set of in-house plan quality metrics (scores) (PlanIQ™, Sun Nuclear Corporation). The metrics compared the class solution for VMAT planning with the IMRT template and the delivered clinical plan (CP). Eight metrics were associated with target coverage and ten with organs-at-risk (OAR). Individual metrics were summed and the combined scores were subjected to non-parametric analysis. The low-dose wash for both static IMRT and VMAT plans were evaluated using 40 Gy and 25 Gy isodose volumes. RESULTS: VMAT plans were of equal or better quality than the IMRT template and CP for target coverage (combined score) and OAR combined score. The 40 Gy isodose volume was marginally higher with VMAT than IMRT (4.9%) but lower than CP (-6.6%)(P = 0.0074). The 25 Gy volume was significantly lower with VMAT than both IMRT (-32.7%) and CP (-34.4%)(P < 0.00001). CONCLUSIONS: Automated VMAT planning for prostate cancer is feasible and the plans are equal to or better than the current IMRT class solution and the delivered clinical plan.

Bottom trawl fishing footprints on the world's continental shelves.

Bottom trawlers land around 19 million tons of fish and invertebrates annually, almost one-quarter of wild marine landings. The extent of bottom trawling footprint (seabed area trawled at least once in a specified region and time period) is often contested but poorly described. We quantify footprints using high-resolution satellite vessel monitoring system (VMS) and logbook data on 24 continental shelves and slopes to 1,000-m depth over at least 2 years. Trawling footprint varied markedly among regions: from <10% of seabed area in Australian and New Zealand waters, the Aleutian Islands, East Bering Sea, South Chile, and Gulf of Alaska to >50% in some European seas. Overall, 14% of the 7.8 million-km2 study area was trawled, and 86% was not trawled. Trawling activity was aggregated; the most intensively trawled areas accounting for 90% of activity comprised 77% of footprint on average. Regional swept area ratio (SAR; ratio of total swept area trawled annually to total area of region, a metric of trawling intensity) and footprint area were related, providing an approach to estimate regional trawling footprints when high-resolution spatial data are unavailable. If SAR was ≤0.1, as in 8 of 24 regions, there was >95% probability that >90% of seabed was not trawled. If SAR was 7.9, equal to the highest SAR recorded, there was >95% probability that >70% of seabed was trawled. Footprints were smaller and SAR was ≤0.25 in regions where fishing rates consistently met international sustainability benchmarks for fish stocks, implying collateral environmental benefits from sustainable fishing.

B-cell receptor-mediated NFATc1 activation induces IL-10/STAT3/PD-L1 signaling in diffuse large B-cell lymphoma.

Knowledge of programmed death ligand 1 (PD-L1) expression and its regulation in B-cell lymphoma cells is limited. Investigating mechanisms that control PD-L1 expression in B-cell lymphoma cells might identify biomarkers that predict the efficacy of immunotherapy with anti-programmed death-1/PD-L1 antibodies. In addition, identification of mechanisms that regulate PD-L1 may identify molecules that can be targeted to improve the clinical efficacy of immune checkpoint inhibitors. In this study, we used proteomic approaches and patient-derived B-cell lymphoma cell lines to investigate mechanisms that regulate PD-L1 expression. We found that PD-L1 expression, particularly in nongerminal center B cell-derived diffuse large B-cell lymphoma (DLBCL), is controlled and regulated by several interactive signaling pathways, including the B-cell receptor (BCR) and JAK2/STAT3 signaling pathways. We found that that BCR-mediated NFATc1 activation upregulates IL-10 chemokine expression in PD-L1+ B-cell lymphoma cells. Released IL-10 activates the JAK2/STAT3 pathway, leading to STAT3-induced PD-L1 expression. IL-10 antagonist antibody abrogates IL-10/STAT3 signaling and PD-L1 protein expression. We also found that BCR pathway inhibition by BTK inhibitors (ibrutinib, acalabrutinib, and BGB-3111) blocks NFATc1 and STAT3 activation, thereby inhibiting IL-10 and PD-L1 expression. Finally, we validated the PD-L1 signaling network in 2 primary DLBCL cohorts consisting of 428 and 350 cases and showed significant correlations among IL-10, STAT3, and PD-L1. Thus, our findings reveal a complex signaling network regulating PD-L1 expression in B-cell lymphoma cells and suggest that PD-L1 expression can be modulated by small molecule inhibitors to potentiate immunotherapies.

Thyroid Hormone Disruption in the Fetal and Neonatal Rat: Predictive Hormone Measures and Bioindicators of Hormone Action in the Developing Cortex.

Adverse neurodevelopmental consequences remain a primary concern when evaluating the effects of thyroid hormone (TH) disrupting chemicals. Though the developing brain is a known target of TH insufficiency, the relationship between THs in the serum and the central nervous system is not well characterized. To address this issue, dose response experiments were performed in pregnant rats using the goitrogen propylthiouracil (PTU) (dose range 0.1-10 ppm). THs were quantified in the serum and brain of offspring at gestational day 20 (GD20) and postnatal day 14 (PN14), two developmental stages included in OECD and EPA regulatory guideline/guidance studies. From the dose response data, the quantitative relationships between THs in the serum and brain were determined. Next, targeted gene expression analyses were performed in the fetal and neonatal cortex to test the hypothesis that TH action in the developing brain is linked to changes in TH concentrations within the tissue. Results show a significant reduction of T4/T3 in the serum and brain of the GD20 fetus in response to low doses of PTU; interestingly, very few genes were significantly different at any dose tested. In the PN14 pup significant reductions of T4/T3 in the serum and brain were also detected; however, twelve transcriptional targets were identified in the neonatal cortex that correlated well with reduced brain THs. These results show that serum T4 is a good predictor of brain THs, and offer several target genes that could serve as pragmatic readouts of T4/T3 dysfunction within the PN14 cortex.

The Role of Macrophage/B-Cell Interactions in the Pathophysiology of B-Cell Lymphomas.

Macrophages (MPs) are heterogeneous, multifunctional, myeloid-derived leukocytes that are part of the innate immune system, playing wide-ranging critical roles in basic biological activities, including maintenance of tissue homeostasis involving clearance of microbial pathogens. Tumor-associated MPs (TAMs) are MPs with defined specific M2 phenotypes now known to play central roles in the pathophysiology of a wide spectrum of malignant neoplasms. Also, TAMs are often intrinsic cellular components of the essential tumor microenvironment (TME). In concert with lymphoid-lineage B and T cells at various developmental stages, TAMs can mediate enhanced tumor progression, often leading to poor clinical prognosis, at least partly through secretion of chemokines, cytokines, and various active proteases shown to stimulate tumor growth, angiogenesis, metastasis, and immunosuppression. Researchers recently showed that TAMs express certain key checkpoint-associated proteins [e.g., programmed cell death protein 1 (PD-1), programmed cell death-ligand 1 (PD-L1)] that appear to be involved in T-cell activation and that these proteins are targets of other specific checkpoint-blocking immunotherapies (anti-PD-1/PD-L1) currently part of new therapeutic paradigms for chemotherapy-resistant neoplasms. Although much is known about the wide spectrum and flexibility of MPs under many normal and neoplastic conditions, relatively little is known about the increasingly important interactions between MPs and B-lymphoid cells, particularly in the TME in patients with aggressive B-cell non-Hodgkin lymphoma (NHL-B). Normal and neoplastic lymphoid and myeloid cell/MP lineages appear to share many primitive cellular characteristics as well as transcriptional factor interactions in human and animal ontogenic studies. Such cells are capable of ectopic transcription factor-induced lineage reprogramming or transdifferentiation from early myeloid/monocytic lineages to later induce B-cell lymphomagenesis in experimental in vivo murine systems. Close cellular interactions between endogenous clonal neoplastic B cells and related aberrant myeloid precursor cells/MPs appear to be important interactive components of aggressive NHL-B that we discuss herein in the larger context of the putative role of B-cell/MP cellular lineage interactions involved in NHL-B pathophysiology during ensuing lymphoma development.

Strategic Therapeutic Targeting to Overcome Venetoclax Resistance in Aggressive B-cell Lymphomas.

Purpose: B-cell lymphoma-2 (BCL-2), an antiapoptotic protein often dysregulated in B-cell lymphomas, promotes cell survival and provides protection from stress. A recent phase I first-in-human study of the BCL-2 inhibitor venetoclax in non-Hodgkin lymphoma showed an overall response rate of 44%. These promising clinical results prompted our examination of the biological effects and mechanism of action underlying venetoclax activity in aggressive B-cell lymphoma, including mantle cell lymphoma (MCL) and diffuse large B-cell lymphoma (DLBCL).Experimental Design: MCL and DLBCL cell lines, primary patient samples, and in vivo patient-derived xenograft (PDX) models were utilized to examine venetoclax efficacy. Furthermore, the mechanisms underlying venetoclax response and the development of venetoclax resistance were evaluated using proteomics analysis and Western blotting.Results: Potential biomarkers linked to venetoclax activity and targeted combination therapies that can augment venetoclax response were identified. We demonstrate that DLBCL and MCL cell lines, primary patient samples, and PDX mouse models expressing high BCL-2 levels are extremely sensitive to venetoclax treatment. Proteomics studies showed that venetoclax substantially alters the expression levels and phosphorylation status of key proteins involved in cellular processes, including the DNA damage response, cell metabolism, cell growth/survival, and apoptosis. Short- and long-term exposure to venetoclax inhibited PTEN expression, leading to enhanced AKT pathway activation and concomitant susceptibility to PI3K/AKT inhibition. Intrinsic venetoclax-resistant cells possess high AKT activation and are highly sensitive to PI3K/AKT inhibition.Conclusions: These findings demonstrate the on-target effect of venetoclax and offer potential mechanisms to overcome acquired and intrinsic venetoclax resistance through PI3K/AKT inhibition. Clin Cancer Res; 24(16); 3967-80. ©2018 AACR.

Preclinical efficacy and biological effects of the oral proteasome inhibitor ixazomib in diffuse large B-cell lymphoma.

Despite advances in deciphering the molecular pathogenesis of diffuse large B-cell lymphoma (DLBCL), patients with relapsed/refractory disease, particularly those with adverse genetic features (e.g., mutated p53 or double hit lymphoma (DHL)) have very poor prognoses, and effective therapies are lacking. In this study we examined the preclinical efficacy and associated biological effects of the first oral proteasome inhibitor, ixazomib, in DLBCL in vitro and in vivo models. We demonstrated that ixazomib exhibited anti-tumor activities in 28 representative DLBCL cell lines, 10 primary DLBCL samples, and a DHL xenotransplant mouse model, at clinically achievable drug concentrations. Ixazomib sensitivity in DLBCL cells is correlated with immunoproteasomal activity; stimulating lymphoma cells with interferon gamma induced immunoproteasome activity and sensitized these cells to ixazomib. In addition, we showed that ixazomib induces apoptosis and the DNA damage response pathway, through activation of the checkpoint kinase 2 (CHK2). Hence, pharmacological inhibition of CHK2 enhances the anti-tumor activity of ixazomib in DLBCL cells. Our results indicate that ixazomib is an effective proteasome inhibitor active in DLBCL, including DHL, and its combination with a CHK2 inhibitor offers a potentially more robust therapeutic regimen for treatment-resistant DLBCL.

The Significance of Hypothermia in Abdominal Aortic Aneurysm Repair.

BACKGROUND: The aim of this study was to review the literature on the association between hypothermia and outcomes in open and endovascular abdominal aortic aneurysm (AAA) repair. The secondary aim was to determine whether there is a difference in body temperature in patients undergoing either transperitoneal (TP), retroperitoneal (RP), or endovascular surgical repair of the abdominal aorta (EVAR). METHODS: MEDLINE, Web of Science, and Trip searched for all studies on temperature in the context of aortic surgery or endovascular aortic interventions. To be included in the review, the papers had to be related to intraoperative or postoperative hypothermia and/or normothermia, with regards to either open or endovascular repair of the abdominal aorta. Thoracic or thoracoabdominal aortic repairs were not included for review. RESULTS: Eight studies involving 765 patients were eligible. Of these, 6 studies looked at open elective AAA repair involving 605 patients. Only 2 studies investigated emergency AAA repair and consisted of 160 patients where only 35 of those patients underwent emergency EVAR. Normothermic patients had a shorter length of stay in the intensive care unit (P = 0.0008), while hypothermia was independently associated with higher rates of organ dysfunction, in-hospital mortality, and prolonged hospital length of stay. In ruptured AAAs, the lowest average intraoperative temperature was recorded in open repair compared with EVAR (P = 0.02). There was no statistically significant difference in postoperative temperature between patients undergoing elective RP repair and those having TP surgery. CONCLUSIONS: The studies identified in this review have shown that hypothermia has numerous deleterious effects on outcomes in AAA repair - whether or not these adverse outcomes are those such as higher rates of organ dysfunction, mortality or prolonged hospital length of stay, can only be done at the single paper level and not at a literature review level, due to multiple confounding variables. Despite these limitations, the benefits of this review are numerous. This article highlights the importance of core body temperature and outcomes of AAA repair. Furthermore, it brings forth the need to standardize the method of core body temperature measurement and method of rewarming. Given the body of evidence so far, these standardized data collection points will be important for national vascular quality improvement initiatives. Only through rigorous analysis of standardized dataset can firm recommendation regarding peri- and postoperative temperature management be made.

Targeting the hexosamine biosynthetic pathway and O-linked N-acetylglucosamine cycling for therapeutic and imaging capabilities in diffuse large B-cell lymphoma.

The hexosamine biosynthetic pathway (HBP) requires two key nutrients glucose and glutamine for O-linked N-acetylglucosamine (O-GlcNAc) cycling, a post-translational protein modification that adds GlcNAc to nuclear and cytoplasmic proteins. Increased GlcNAc has been linked to regulatory factors involved in cancer cell growth and survival. However, the biological significance of GlcNAc in diffuse large B-cell lymphoma (DLBCL) is not well defined. This study is the first to show that both the substrate and the endpoint O-GlcNAc transferase (OGT) enzyme of the HBP were highly expressed in DLBCL cell lines and in patient tumors compared with normal B-lymphocytes. Notably, high OGT mRNA levels were associated with poor survival of DLBCL patients. Targeting OGT via small interference RNA in DLBCL cells inhibited activation of GlcNAc, nuclear factor kappa B (NF-κB), and nuclear factor of activated T-cells 1 (NFATc1), as well as cell growth. Depleting both glucose and glutamine in DLBCL cells or treating them with an HBP inhibitor (azaserine) diminished O-GlcNAc protein substrate, inhibited constitutive NF-κB and NFATc1 activation, and induced G0/G1 cell-cycle arrest and apoptosis. Replenishing glucose-and glutamine-deprived DLBCL cells with a synthetic glucose analog (ethylenedicysteine-N-acetylglucosamine [ECG]) reversed these phenotypes. Finally, we showed in both in vitro and in vivo murine models that DLBCL cells easily take up radiolabeled technetium-99m-ECG conjugate. These findings suggest that targeting the HBP has therapeutic relevance for DLBCL and underscores the imaging potential of the glucosamine analog ECG in DLBCL.

Establishment and characterization of a novel MYC/BCL2 "double-hit" diffuse large B cell lymphoma cell line, RC.

BACKGROUND: Diffuse large B cell lymphoma (DLBCL) is the most common type of lymphoid malignancy worldwide. Approximately 5 % of cases of DLBCL are so-called double-hit lymphomas (DHL), defined by a chromosomal translocation or rearrangement involving MYC/8q24.2 in combination with another recurrent breakpoint, usually BCL2/18q21.3. Patients with MYC/BCL2 DHL are resistant to standard front-line therapy, and currently, there is no consensus for a therapeutic strategy to treat these patients. Lack of clinically relevant or validated human experimental DHL models of any type that would improve our understanding of the biologic basis of MYC/BCL2 DHL pathophysiology continues to hamper identification of valid therapeutic targets. We describe a unique MYC/BCL2 DHL cell line with morphologic features of DLBCL that we have established, designated as RC. METHODS: We used tissue culture techniques to establish the RC cell line from primary DLBCL cells. We also utilized molecular and cellular biological techniques including flow cytometry, polymerase chain reaction (PCR), DNA fingerprinting, reverse-phase protein array, conventional cytogenetics, and fluorescence in situ hybridization (FISH) analysis to characterize the RC cell line. NSG-severe combined immunodeficiency (SCID) mice were utilized as a model for xeno-transplantation of RC cells. RESULTS: RC cells had the following immunophenotype: positive for CD10, CD19, CD20, CD22, CD38, CD43, CD44, and CD79b and negative for CD3, CD4, CD5, CD8, CD11c, CD14, CD30, CD56, and CD200, which was identical to the primary tumor cells. Conventional cytogenetic analysis showed a t(2;8)(p12;q24.2) and t(14;18)(q32;q21.3), corresponding to MYC and BCL2 gene rearrangements, respectively. DNA fingerprinting authenticated the RC cell line to be of the same clone as the primary tumor cells. In addition, RC cells were established in SCID mice as an in vivo model for translational therapeutics studies. Proteomic analysis showed activation of the mTOR signaling pathway in RC cells that can be targeted with an mTOR inhibitor. CONCLUSION: The data presented confirm the validity of the RC cell line as a representative model of MYC/BCL2 DHL that will be useful for both in vitro and in vivo studies of DHL pathogenesis and therapeutics.