An international multicenter retrospective analysis of patients with extranodal marginal zone lymphoma and histologically confirmed central nervous system and dural involvement

Marginal zone lymphoma of the central nervous system (CNS MZL) is rare. The clinical features, treatment, and prognosis are not well characterized. We performed a multicenter retrospective study of CNS MZL. Twenty-six patients were identified: half with primary and half with secondary CNS involvement. The median age was 59 years (range 26-78), 62% female and 79% with ECOG performance status ≤ 1. The most common disease site was the dura (50%). Treatment was determined by the treating physician and varied substantially. After a median follow up of 1.9 years, the estimated 2-year progression-free (PFS) and overall survival (OS) rates were 59% and 80%, respectively. Secondary CNS MZL was associated with 2-year OS of 58%. CNS MZL is rare, but relative to other forms of CNS lymphoma, outcomes appear favorable, particularly among the subset of patients with dural presentation and primary CNS presentation

Vorinostat Combined with High-Dose Gemcitabine, Busulfan, and Melphalan with Autologous Stem Cell Transplantation in Patients with Refractory Lymphomas

AbstractMore active high-dose regimens are needed for refractory/poor-risk relapsed lymphomas. We previously developed a regimen of infusional gemcitabine/busulfan/melphalan, exploiting the synergistic interaction. Its encouraging activity in refractory lymphomas led us to further enhance its use as a platform for epigenetic modulation. We previously observed increased cytotoxicity in refractory lymphoma cell lines when the histone deacetylase inhibitor vorinostat was added to gemcitabine/busulfan/melphalan, which prompted us to clinically study this four-drug combination. Patients ages 12 to 65 with refractory diffuse large B cell lymphoma (DLCL), Hodgkin (HL), or T lymphoma were eligible. Vorinostat was given at 200 mg/day to 1000 mg/day (days −8 to −3). Gemcitabine was infused continuously at 10 mg/m2/minute over 4.5 hours (days −8 and −3). Busulfan dosing targeted 4000 μM-minute/day (days −8 to −5). Melphalan was infused at 60 mg/m2/day (days −3 and −2). Patients with CD20+ tumors received rituximab (375 mg/m2, days +1 and +8). We enrolled 78 patients: 52 DLCL, 20 HL, and 6 T lymphoma; median age 44 years (range, 15 to 65); median 3 prior chemotherapy lines (range, 2 to 7); and 48% of patients had positron emission tomography–positive tumors at high-dose chemotherapy (29% unresponsive). The vorinostat dose was safely escalated up to 1000 mg/day, with no treatment-related deaths. Toxicities included mucositis and dermatitis. Neutrophils and platelets engrafted promptly. At median follow-up of 25 (range, 16 to 41) months, event-free and overall survival were 61.5% and 73%, respectively (DLCL) and 45% and 80%, respectively (HL). In conclusion, vorinostat/gemcitabine/busulfan/melphalan is safe and highly active in refractory/poor-risk relapsed lymphomas, warranting further evaluation

Inhibition of endothelial cell proliferation by Notch1 signaling is mediated by repressing MAPK and PI3K/Akt pathways and requires MAML1

The requirement for Notch signaling in vasculogenesis and angiogenesis is well documented. In a previous study, we showed that activation of the Notch pathway in endothelial cells induces differentiation-associated growth arrest; however, the underlying mechanism remains to be elucidated. Here, we show that activation of the Notch pathway by either stimulation of cell surface Notch receptors with crosslinked soluble delta-like 4 (sDll4)/Jagged1 (sJag1) or constitutive expression of the Notch1 intracellular domain (N(IC)) suppresses endothelial cell proliferation. This suppression is mediated by the mitogen-activated protein kinase (MAPK) and phosphatidylinositol 3-kinase (PI3K)/Akt pathways. Following Notch1 activation, both pathways were suppressed in endothelial cells, and alterations in MAPK or PI3K/Akt pathway activity reversed Notch1-induced growth inhibition. Furthermore, we found the effect of Notch1 on endothelial cells to require Mastermind-like (MAML). Overexpression of a dominant-negative mutant of MAML1 antagonized the effects of activated Notch1 on the MAPK and PI3K/Akt pathways. Ectopic expression of Hairy/Enhancer of Split 1 (HES1) consistently reproduced the inhibitory effect of N(IC) on endothelial cell proliferation. Together, our data demonstrate that the Notch/MAML-HES signaling cascade can regulate both MAPK and PI3K/Akt pathways, which suggests a molecular mechanism for the inhibitory effect of Notch signaling on endothelial cell proliferation

Notch1 signaling promotes primary melanoma progression by activating mitogen-activated protein kinase/phosphatidylinositol 3-kinase-Akt pathways and up-regulating N-cadherin expression

Cellular signaling mediated by Notch receptors results in coordinated regulation of cell growth, survival, and differentiation. Aberrant Notch activation has been linked to a variety of human neoplasms. Here, we show that Notch1 signaling drives the vertical growth phase (VGP) of primary melanoma toward a more aggressive phenotype. Constitutive activation of Notch1 by ectopic expression of the Notch1 intracellular domain enables VGP primary melanoma cell lines to proliferate in a serum-independent and growth factor-independent manner in vitro and to grow more aggressively with metastatic activity in vivo. Notch1 activation also enhances tumor cell survival when cultured as three-dimensional spheroids. Such effects of Notch signaling are mediated by activation of the mitogen-activated protein kinase (MAPK) and Akt pathways. Both pathways are activated in melanoma cells following Notch1 pathway activation. Inhibition of either the MAPK or the phosphatidylinositol 3-kinase (PI3K)-Akt pathway reverses the Notch1 signaling-induced tumor cell growth. Moreover, the growth-promoting effect of Notch1 depends on mastermind-like 1. We further showed that Notch1 activation increases tumor cell adhesion and up-regulates N-cadherin expression. Our data show regulation of MAPK/PI3K-Akt pathway activities and expression of N-cadherin by the Notch pathway and provide a mechanistic basis for Notch signaling in the promotion of primary melanoma progression

Activation of Notch1 signaling is required for β-catenin–mediated human primary melanoma progression

Notch is a highly conserved transmembrane receptor that determines cell fate. Notch signaling denotes cleavage of the Notch intracellular domain, its translocation to the nucleus, and subsequent activation of target gene transcription. Involvement of Notch signaling in several cancers is well known, but its role in melanoma remains poorly characterized. Here we show that the Notch1 pathway is activated in human melanoma. Blocking Notch signaling suppressed whereas constitutive activation of the Notch1 pathway enhanced primary melanoma cell growth both in vitro and in vivo yet had little effect on metastatic melanoma cells. Activation of Notch1 signaling enabled primary melanoma cells to gain metastatic capability. Furthermore, the oncogenic effect of Notch1 on primary melanoma cells was mediated by β-catenin, which was upregulated following Notch1 activation. Inhibiting β-catenin expression reversed Notch1-enhanced tumor growth and metastasis. Our data therefore suggest a β-catenin–dependent, stage-specific role for Notch1 signaling in promoting the progression of primary melanoma

Using benchmarked lung radiation dose constraints to predict pneumonitis risk: Developing a nomogram for patients with mediastinal lymphoma

Purpose: We identified lung dosimetric constraints to assist in predicting the radiation pneumonitis (RP) risk in patients with mediastinal lymphoma and then identified the clinical prognostic factors that were associated with the achievement of key dosimetric constraints. Methods and Materials: In 190 patients who received mediastinal intensity modulated radiation therapy, we used univariate χ2 and multivariate logistic models to identify the predictors of RP and achievement of lung dose-volume histogram (DVH) constraints and build a predictive nomogram for RP. Results: An increased risk of RP was strongly associated with mean lung dose (MLD) > 13.5 Gy (odds ratio [OR]: 8.13; 95% confidence interval [CI], 3.01-21.93; P  55% (OR: 7.01; 95% CI, 2.94-16.72; P < .001). Therefore, patients had low RP risk (8%) if both MLD ≤13.5 and V5 ≤55 constraints were achieved, moderate risk (24%) if only MLD was achieved, and the highest risk (48%) if MLD was not achieved. Deep-inspiration breath-hold (DIBH) technique during treatment strongly prognosticated achieving MLD and V5 DVH constraints (OR,3.88; 95% CI, 1.84-8.19; P < .001). Specifically, 86% of patients who were treated with DIBH versus 63% without DIBH achieved DVH constraints (P < .001). This translated into a “number needed to treat” with DIBH of 4 patients to enable 1 additional patient to achieve both constraints. In comparison, the clinical characteristics were marginal prognosticators: DVH constraints were more likely achieved in nonbulky disease (OR: 3.01; 95% CI, 0.89-4.53; P = .09) and patients who had not previously received salvage chemotherapy (OR, 2.44; 95% CI, 0.98-6.11; P = .06). Nomogram-predicted risks of RP ranged from 4% to 60% on the basis of MLD and V5, total radiation dose, and use of salvage chemotherapy. Conclusions: Achieving mean lung and V5 DVH constraints is critical to reduce RP risk in patients with lymphoma who receive mediastinal intensity modulated radiation therapy. The use of the DIBH technique is a promising risk-modifying treatment approach in patients with mediastinal lymphoma and especially in patients with a history of nonmodifiable risk factors for RP such as bulky disease and salvage chemotherapy