Dataset Information

Systemic Tolerance Mediated by Melanoma Brain Tumors Is Reversible by Radiotherapy and Vaccination.

ABSTRACT:

Purpose

Immune responses to antigens originating in the central nervous system (CNS) are generally attenuated, as collateral damage can have devastating consequences. The significance of this finding for the efficacy of tumor-targeted immunotherapies is largely unknown.

Experimental design

The B16 murine melanoma model was used to compare cytotoxic responses against established tumors in the CNS and in the periphery. Cytokine analysis of tissues from brain tumor-bearing mice detected elevated TGFβ secretion from microglia and in the serum and TGFβ signaling blockade reversed tolerance of tumor antigen-directed CD8 T cells. In addition, a treatment regimen using focal radiation therapy and recombinant Listeria monocytogenes was evaluated for immunologic activity and efficacy in this model.

Results

CNS melanomas were more tolerogenic than equivalently progressed tumors outside the CNS as antigen-specific CD8 T cells were deleted and exhibited impaired cytotoxicity. Tumor-bearing mice had elevated serum levels of TGFβ; however, blocking TGFβ signaling with a small-molecule inhibitor or a monoclonal antibody did not improve survival. Conversely, tumor antigen-specific vaccination in combination with focal radiation therapy reversed tolerance and improved survival. This treatment regimen was associated with increased polyfunctionality of CD8 T cells, elevated T effector to T regulatory cell ratios, and decreased TGFβ secretion from microglia.

Conclusions

These data suggest that CNS tumors may impair systemic antitumor immunity and consequently accelerate cancer progression locally as well as outside the CNS, whereas antitumor immunity may be restored by combining vaccination with radiation therapy. These findings are hypothesis-generating and warrant further study in contemporary melanoma models as well as human trials.

SUBMITTER: Jackson CM

PROVIDER: S-EPMC4825863 | biostudies-literature | 2016 Mar

REPOSITORIES: biostudies-literature

ACCESS DATA

Publications

Systemic Tolerance Mediated by Melanoma Brain Tumors Is Reversible by Radiotherapy and Vaccination.

Jackson Christopher M CM Kochel Christina M CM Nirschl Christopher J CJ Durham Nicholas M NM Ruzevick Jacob J Alme Angela A Francica Brian J BJ Elias Jimmy J Daniels Andrew A Dubensky Thomas W TW Lauer Peter P Brockstedt Dirk G DG Baxi Emily G EG Calabresi Peter A PA Taube Janis M JM Pardo Carlos A CA Brem Henry H Pardoll Drew M DM Lim Michael M Drake Charles G CG

Clinical cancer research : an official journal of the American Association for Cancer Research 20151021 5

<h4>Purpose</h4>Immune responses to antigens originating in the central nervous system (CNS) are generally attenuated, as collateral damage can have devastating consequences. The significance of this finding for the efficacy of tumor-targeted immunotherapies is largely unknown.<h4>Experimental design</h4>The B16 murine melanoma model was used to compare cytotoxic responses against established tumors in the CNS and in the periphery. Cytokine analysis of tissues from brain tumor-bearing mice detec ...[more]

PMID: 26490306

Similar Datasets

Project description:BackgroundNeurological decline during radio(chemo)therapy of the brain is often attributed to disease progression or side effects of radiotherapy. Diagnosis of opportunistic neurotropic infections such as cytomegalovirus (CMV) infections is uncommon, even though high-grade gliomas and some brain metastases are known to contain CMV particles. We prospectively examined the frequency of CMV encephalopathy during radiotherapy of the brain.MethodsFifty patients requiring whole-brain radiotherapy for brain metastases (n = 27) or local radio(chemo)therapy of the brain for high-grade gliomas (n = 23) were observed in the prospective observational GLIO-CMV-01 study. MRIs and blood samples were obtained before, halfway through, and at the end of radiotherapy. MRIs were screened for disease progression or increased intracranial pressure. Blood was tested for anti-CMV immunoglobulin (Ig)M, anti-CMV IgG, and CMV DNA.ResultsThirty-two of 50 (64%) patients were positive for anti-CMV IgG before radio(chemo)therapy. Fifteen of those 32 (48%) developed viremia during or up to 28 days after treatment. Thirteen of those 15 (87%) required treatment for CMV-associated encephalopathy. MRIs were negative for disease progression, edema, or bleeding. None of the patients negative for anti-CMV IgG developed viremia, suggesting a reactivation rather than a primary infection.In the group at risk consisting of anti-CMV IgG+ patients, age >65 (P = .004) and the amount of dexamethasone taken during radio(chemo)therapy (P = .004) were associated with an increased risk for CMV-associated encephalopathy. One hundred and fifty days after the start of radio(chemo)therapy, survival was 74% (14/19) (no encephalopathy) versus 54% (7/13) (encephalopathy) (odds ratio, 0.42; 95% CI, 0.03-1.86; P = .25).ConclusionCMV reactivation frequently causes encephalopathy during radio(chemo)therapy of the brain. The unexpected high incidence of this infection makes it highly clinically relevant for every treating physician.

Project description:Few data are available on patients with leptomeningeal disease (LM) from melanoma treated with new systemic therapies. To gain a better understanding of patients, disease characteristics, and therapeutic interventions in melanoma patients with LM in the era of new systemic treatment. Clinical characteristics, treatments, and survival of melanoma patients diagnosed with LM, isolated or associated with brain metastases, were collected. The Cox regression model assessed the influence of patient and melanoma characteristics on survival. Monocentric, retrospective, real-life cohort of patients with LM from melanoma. All patients followed up at Saint-Louis University Hospital and diagnosed with LM between December 2013 and February 2020 were included. For each patient identified, a central review by dermato-oncologist and neuro-oncologist experts was performed to confirm the diagnosis of LM. Impact of new systemic therapies and radiotherapy. Among the 452 advanced melanoma patients followed at St Louis Hospital between 2013 and 2020, 41 patients with LM from melanoma were identified. Among them, 29 patients with a diagnosis of LM "confirmed" or "probable" after central neuro-oncologists reviewing were included. Nineteen patients had known melanoma brain metastases at LM diagnosis. Among the 27 patients treated with systemic therapy, 17 patients were treated with immunotherapy, 5 patients received targeted therapy, 1 was treated with chemotherapy, and 4 patients were treated with anti-PD-1 in combination with BRAF inhibitor. The median overall survival (OS) from LM diagnosis was 5.1 months. Median OS was 7.1 months for the 9 patients receiving systemic therapy combined with radiotherapy, and 3.2 months for the 20 patients not receiving combined radiotherapy. Elevated serum lactate dehydrogenase (LDH) (HR 1.44, 95% CI 1.09-1.90, p < 0.01) and presence of neurological symptoms at LM diagnosis (HR 2.96, 95% CI 1.25-6.99, p = 0.01) were associated with poor survival. At the time of data analysis, five patients were still alive with a median follow-up of 47.4 months and had persistent complete response. Targeted therapy and immunotherapy are promising new treatment options in LM from melanoma that can increase overall survival, and may induce long lasting remission in some patients.

Project description:The incidence of brain metastases of solid tumors is increasing. Local treatment of brain metastases is generally straightforward: cranial radiotherapy (e.g., whole-brain radiotherapy or stereotactic radiosurgery) or resection when feasible. However, treatment becomes more complex when brain metastases occur while other metastases, outside of the central nervous system, are being controlled with systemic therapy (chemotherapeutics, molecular targeted agents, or monoclonal antibodies). It is known that some anticancer agents can increase the risk for neurotoxicity when used concurrently with radiotherapy. Increased neurotoxicity decreases quality of life, which is undesirable in this predominantly palliative patient group. Therefore, it is of utmost importance to identify the compounds that should be temporarily discontinued when cranial radiotherapy is needed.This review summarizes the (neuro)toxicity data for combining systemic therapy (chemotherapeutics, molecular targeted agents, or monoclonal antibodies) with concurrent radiotherapy of brain metastases. Because only a limited amount of high-level data has been published, a risk assessment of each agent was done, taking into account the characteristics of each compound (e.g., lipophilicity) and the microenvironment of brain metastasis. The available trials suggest that only gemcitabine, erlotinib, and vemurafenib induce significant neurotoxicity when used concurrently with cranial radiotherapy. We conclude that for most systemic therapies, the currently available literature does not show an increase in neurotoxicity when these therapies are used concurrently with cranial radiotherapy. However, further studies are needed to confirm safety because there is no high-level evidence to permit definitive conclusions. The Oncologist 2017;22:222-235Implications for Practice: The treatment of symptomatic brain metastases diagnosed while patients are receiving systemic therapy continues to pose a dilemma to clinicians. Will concurrent treatment with cranial radiotherapy and systemic therapy (chemotherapeutics, molecular targeted agents, and monoclonal antibodies), used to control intra- and extracranial tumor load, increase the risk for neurotoxicity? This review addresses this clinically relevant question and evaluates the toxicity of combining systemic therapies with cranial radiotherapy, based on currently available literature, in order to determine the need to and interval to interrupt systemic treatment.

Project description:Background and purposeProton radiotherapy has been increasingly utilized to treat pediatric brain tumors, however, limited information exists regarding radiation necrosis among these patients. Our aim was to evaluate the incidence, timing, clinical significance, risk factors, and imaging patterns of radiation necrosis in pediatric patients with brain tumors treated with proton radiation therapy.Materials and methodsA retrospective study was performed on 60 consecutive pediatric patients with primary brain tumors treated with proton radiation therapy. Radiation necrosis was assessed by examining serial MRIs and clinical records to determine the incidence, timing, risk factors, imaging patterns, and clinical significance associated with the development of radiation necrosis in these patients. Radiation necrosis was defined as areas of new enhancement within an anatomic region with previous exposure to proton beam therapy with subsequent decrease on follow-up imaging without changes in chemotherapy.ResultsThirty-one percent of patients developed radiation necrosis with a median time to development of 5.0 months (range, 3-11 months). Risk factors included multiple chemotherapy agents (>3 cytotoxic agents) and atypical teratoid rhabdoid tumor pathology (P = .03 and P = .03, respectively). The most common imaging patterns were small (median, 0.9 cm) and multifocal (63% of patients) areas of parenchymal enhancement remote from the surgical site. The median time to complete resolution on imaging was 5.3 months (range, 3-12 months). Among patients with imaging findings of radiation necrosis, 25% demonstrated severe symptoms with medical intervention indicated.ConclusionsPediatric patients with brain tumors treated with proton radiation therapy demonstrate a high incidence of radiation necrosis and a short time to development of necrosis. Multiple small areas of necrosis are frequently identified on imaging. Exposure to multiple chemotherapy agents was a significant risk factor associated with radiation necrosis in these patients.

Project description:Here, we aimed to investigate the potential role of DUSP6, a dual specificity phosphatase, that specifically inactivates extracellular signal-regulated kinase (ERK), for the regulation of body weight and glucose homeostasis. We further assessed whether metabolic challenges affect Dusp6 expression in selected brain areas or white adipose tissue. Hypothalamic Dusp6 mRNA levels remained unchanged in chow-fed lean vs. high fat diet (HFD) fed obese C57Bl/6J mice, and in C57Bl/6J mice undergoing prolonged fasting or refeeding with fat free diet (FFD) or HFD. Similarly, Dusp6 expression levels were unchanged in selected brain regions of Lepob mice treated with 1 mg/kg of leptin for 6 days, compared to pair-fed or saline-treated Lepob controls. Dusp6 expression levels remained unaltered in vitro in primary adipocytes undergoing differentiation, but were increased in eWAT of HFD-fed obese C57Bl/6J mice, compared to chow-fed lean controls. Global chow-fed DUSP6 KO mice displayed reduced body weight and lean mass and slightly increased fat mass at a young age, which is indicative for early-age weight retardation. Subsequent exposure to HFD led to a significant increase in lean mass and body weight in DUSP6 deficient mice, compared to WT controls. Nevertheless, after 26 weeks of high-fat diet exposure, we observed comparable body weight, fat and lean mass in DUSP6 WT and KO mice, suggesting overall normal susceptibility to develop obesity. In line with the increased weight gain to compensate for early-age weight retardation, HFD-fed DUSP6 KO displayed increased expression levels of anabolic genes involved in lipid and cholesterol metabolism in the epididymal white adipose tissue (eWAT), compared to WT controls. Glucose tolerance was perturbed in both chow-fed lean or HFD-fed obese DUSP6 KO, compared to their respective WT controls. Overall, our data indicate that DUSP6 deficiency has limited impact on the regulation of energy metabolism, but impairs systemic glucose tolerance. Our data are in conflict to earlier reports that propose protection from diet-induced obesity and glucose intolerance in DUSP6 deficient mice. Reasons for the discrepancies remain elusive, but may entail differential genetic backgrounds, environmental factors such as the type and source of HFD, or alterations in the gut microbiome between facilities.

Dataset Information

Systemic Tolerance Mediated by Melanoma Brain Tumors Is Reversible by Radiotherapy and Vaccination.

Purpose

Experimental design

Results

Conclusions

Publications

Systemic Tolerance Mediated by Melanoma Brain Tumors Is Reversible by Radiotherapy and Vaccination.

Similar Datasets

OmicsDI is part of the ELIXIR infrastructure

Tweets