Glutamine deficiency is a well-known feature of the tumor environment. Here we analyzed the impact of glutamine deprivation on human myeloid cell survival and function.
Different types of myeloid ...cells were cultured in the absence or presence of glutamine and/or with L-methionine-S-sulfoximine (MSO), an irreversible glutamine synthetase (GS) inhibitor. GS expression was analyzed on mRNA and protein level. GS activity and the conversion of glutamate to glutamine by myeloid cells was followed by 13C tracing analyses.
The absence of extracellular glutamine only slightly affected postmitotic human monocyte to dendritic cell (DC) differentiation, function and survival. Similar results were obtained for monocyte-derived macrophages. In contrast, proliferation of the monocytic leukemia cell line THP-1 was significantly suppressed. While macrophages exhibited high constitutive GS expression, glutamine deprivation induced GS in DC and THP-1. Accordingly, proliferation of THP-1 was rescued by addition of the GS substrate glutamate and 13C tracing analyses revealed conversion of glutamate to glutamine. Supplementation with the GS inhibitor MSO reduced the survival of DC and macrophages and counteracted the proliferation rescue of THP-1 by glutamate.
Our results show that GS supports myeloid cell survival in a glutamine poor environment. Notably, in addition to suppressing proliferation and survival of tumor cells, the blockade of GS also targets immune cells such as DCs and macrophages.
Metastasized soft-tissue sarcomas still pose a significant therapeutic challenge given the limited efficacy of currently available multimodal treatment strategies. Recent progress in molecular ...characterization of sarcoma subtypes has enabled successful personalized therapy approaches in a minority of selected patients with targetable mutations. However, in the majority of patients with refractory soft tissue sarcomas, long-term survival remains poor.
We report on three adult patients with various soft tissue sarcomas subjected to Gemcitabine maintenance therapy. Tumor entities included leiomyosarcoma of the pancreas (patient 1), undifferentiated pleomorphic sarcoma of the right femur (patient 2), and peri-aortic leiomyosarcoma (patient 3). Metastatic sites encompassed liver, lung, and bones. All patients received Gemcitabine maintenance therapy until disease progression following prior salvage chemotherapy with Docetaxel and Gemcitabine. Patients were treated outside of clinical trials. Response assessment was based on radiological imaging.
In response to salvage chemotherapy with Docetaxel and Gemcitabine, one patient exhibited a partial remission, and two patients showed stable disease. Patient 1 exhibited stable disease for 6 months during Gemcitabine maintenance therapy before suffering rapid progression of hepatic metastases. Patient 2 underwent 21 months of Gemcitabine maintenance therapy, which was discontinued after progressive pulmonary metastases were detected. Patient 3 is still being treated with Gemcitabine maintenance therapy. Remarkably, owing to significant chemotherapy-associated hematotoxicity, the dose of Gemcitabine dose was reduced by two-thirds. Nevertheless, stable disease with constant pulmonary metastases has been maintained in this patient for 14 months.
Gemcitabine maintenance therapy following prior Docetaxel and Gemcitabine chemotherapy is manageable and reveals potential benefits for patients with aggressive metastasized soft tissue sarcomas. Prospective trials evaluating Gemcitabine maintenance therapy are encouraged.
Melanoma and squamous cell carcinoma of the skin are characterized by an altered glucose metabolism, but little is known about metabolic changes in precancerous skin lesions such as actinic keratosis ...(AK). Here, we studied the central carbon metabolism and immune cell infiltrate of actinic keratosis lesions before, under, and 4 weeks after treatment with topical diclofenac (Solaraze®).
This study was designed as a prospective, randomized, controlled, monocentric investigation (ClinicalTrials.gov Identifier: NCT01935531). Myeloid and T cell infiltration was analyzed in skin biopsies from 28 patients by immunohistochemistry. Furthermore, immune cell activation was determined via quantitative real-time PCR (
γ, IL-10,
β
). Glucose, amino acid and Krebs' cycle metabolism was studied by mass spectrometry prior, during and after treatment with topical diclofenac. Biopsies from sun-exposed, untreated, healthy skin served as controls.
Increased lactate and decreased glucose levels suggested accelerated glycolysis in pre-treatment AK. Further, levels of Krebs' cycle intermediates other than citrate and amino acids were elevated. Analysis of the immune infiltrate revealed less epidermal CD1a+ cells but increased frequencies of dermal CD8+ T cells in AK. Treatment with diclofenac reduced lactate and amino acid levels in AK, especially in responding lesions, and induced an infiltration of dermal CD8+ T cells accompanied by high
γ mRNA expression, suggesting improved T cell function.
Our study clearly demonstrated that not only cancers but also pre-malignant skin lesions, like AK, exhibit profound changes in metabolism, correlating with an altered immune infiltrate. Diclofenac normalizes metabolism, immune cell infiltration and function in AK lesions, suggesting a novel mechanism of action.
Classic tumor therapy, consisting of cytotoxic agents and/or targeted therapy, has not overcome therapeutic limitations like poor risk genetic parameters, genetic heterogeneity at different ...metastatic sites or the problem of undruggable targets. Here we summarize data and trials principally following a completely different treatment concept tackling systems biologic processes: the principle of communicative reprogramming of tumor tissues, i.e.,
, aims at establishing novel communicative behavior of tumor tissue, the hosting organ and organism via re-modeling gene expression, thus recovering differentiation, and apoptosis competence leading to cancer control - in contrast to an immediate, "poisoning" with maximal tolerable doses of targeted or cytotoxic therapies. Therefore, we introduce the term "Master modulators" for drugs or drug combinations promoting evolutionary processes or regulating homeostatic pathways. These "master modulators" comprise a broad diversity of drugs, characterized by the capacity for reprogramming tumor tissues, i.e., transcriptional modulators, metronomic low-dose chemotherapy, epigenetically modifying agents, protein binding pro-anakoinotic drugs, such as COX-2 inhibitors, IMiDs etc., or for example differentiation inducing therapies. Data on 97 anakoinosis inducing schedules indicate a favorable toxicity profile: The combined administration of master modulators, frequently (with poor or no monoactivity) may even induce continuous complete remission in refractory metastatic neoplasia, irrespectively of the tumor type. That means recessive components of the tumor, successively developing during tumor ontogenesis, are accessible by regulatory active drug combinations in a therapeutically meaningful way. Drug selection is now dependent on situative systems characteristics, to less extent histology dependent. To sum up, anakoinosis represents a new substantive therapy principle besides novel targeted therapies.
•We present an unusual case of a young COVID-19 patient presenting with hyperinflammation and severe liver injury.•The underlying causative events were sHLH, hepatic SARS-CoV-2 infection induced by ...immunosuppression and Wilson’s disease.•SARS-CoV-2 was detected in hepatocytes by EM as well as virus isolation from a diagnostic liver biopsy.•When immunosuppression is applied, (systemic) virus replication has to be closely monitored.
A 21-year-old woman was hospitalized due to coronavirus disease 2019 (COVID-19)-associated respiratory and hepatic impairment concomitant with severe hemolytic anemia. Upon diagnosis of secondary hemophagocytic lymphohistiocytosis, immunosuppression with anakinra and steroids was started, leading to a hepatic severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection and viremia. Subsequent liver biopsy revealed virus particles in hepatocytes by electron microscopy and SARS-CoV-2 virus could be isolated and cultured. Immunosuppression was stopped and convalescent donor plasma given. In the differential diagnosis, an acute crisis of Wilson’s disease was raised by laboratory and genetic testing. This case highlights the complexity of balancing immunosuppression to control hyperinflammation versus systemic SARS-CoV-2 dissemination.
Functional systemic and local immunity is required for effective anti-tumor responses. In addition to an active engagement with cancer cells and tumor stroma, immune cells can be affected and are ...often found to be dysregulated in cancer patients. The impact of tumors on local and systemic immunity can be assessed using a variety of approaches ranging from low-dimensional analyses that are performed on large patient cohorts to multi-dimensional assays that are technically and logistically challenging and are therefore confined to a limited sample size. Many of these strategies have been established in recent years leading to exciting findings. Not only were analyses of immune cells in tumor patients able to predict the clinical course of the disease and patients' survival, numerous studies also detected changes in the immune landscape that correlated with responses to novel immunotherapies. This review will provide an overview of established and novel tools for assessing immune cells in tumor patients and will discuss exemplary studies that utilized these techniques to predict patient outcomes.
HLA mismatch antigens are major targets of alloreactive T cells in HLA-incompatible stem-cell transplantation, which can trigger severe graft-versus-host disease and reduce survival in transplant ...recipients. Our objective was to identify T-cell subsets with reduced in vitro reactivity to allogeneic HLA antigens.
We sorted CD4 and CD8 T-cell subsets from peripheral blood by flow cytometry according to their expression of naive and memory markers CD45RA, CD45RO, CD62L, and CCR7. Subsets were defined by a single marker to facilitate future establishment of a clinical-grade procedure for reducing alloreactive T-cell precursors and graft-versus-host disease. T cells were stimulated in mixed lymphocyte reactions against HLA-deficient K562 cells transfected with single HLA-A/-B/-C/-DR/-DQ mismatch alleles. Alloreactivity was measured by interferon-γ spot production and cell proliferation.
We observed that allogeneic HLA-reactivity was preferentially derived from subsets enriched for naïve T cells rather than memory T cells in healthy donors, irrespective of the HLA mismatch allele. This separation was most efficient if CD45RA (versus other markers) was used for sorting. The numbers of allogeneic HLA-reactive effector cells were in median 7.2-fold and 16.6-fold lower in CD45RA(neg) memory CD8 and CD4 T cells than in entire CD8 and CD4 T cells, respectively. In contrast, proliferation of memory T cells in response to allogeneic HLA was more variably reduced (CD8) or equivalent (CD4) when compared to that of naïve T cells. We also demonstrated in HLA-matched donor-patient pairs that leukemia-reactive CD8 cytotoxic T-lymphocytes were mainly derived from subsets enriched for naïve T cells compared to memory T cells.
Memory T-cell subsets of most healthy individuals showed decreased allogeneic HLA-reactivity, but lacked significant anti-leukemia responses in vitro. The clinical use of memory or naïve-depleted T cells might be beneficial for HLA-mismatched patients at high risk of graft-versus-host disease and low risk of leukemia relapse. Preferred allografts are those which contain leukemia-reactive memory T cells. Alternatively, replenishment with leukemia-reactive T cells isolated from naïve subsets is desirable.
Most non-small cell lung cancers occur in elderly and frequently comorbid patients. Therefore, it is necessary to evaluate the efficacy of biomodulatory active therapy regimen, concertedly ...interfering with tumor-associated homeostatic pathways to achieve tumor control paralleled by modest toxicity profiles.
The ModuLung trial is a national, multicentre, prospective, open-label, randomized phase II trial in patients with histologically confirmed stage IIIB/IV squamous (
= 11) and non-squamous non-small cell (
= 26) lung cancer who failed first-line platinum-based chemotherapy. Patients were randomly assigned on a 1:1 ratio to the biomodulatory or control group, treated with nivolumab. Patients randomized to the biomodulatory group received an all-oral therapy consisting of treosulfan 250 mg twice daily, pioglitazone 45 mg once daily, clarithromycin 250 mg twice daily, until disease progression or unacceptable toxicity.
The study had to be closed pre-maturely due to approval of immune checkpoint inhibitors (ICi) in first-line treatment. Thirty-seven patients, available for analysis, were treated in second to forth-line. Progression-free survival (PFS) was significantly inferior for biomodulation (
= 20) vs. nivolumab (
= 17) with a median PFS (95% confidence interval) of 1.4 (1.2-2.0) months vs. 1.6 (1.4-6.2), respectively; with a hazard ratio (95% confidence interval) of 1.908 0.962; 3.788;
= 0.0483. Objective response rate was 11.8% with nivolumab vs. 5% with biomodulation, median follow-up 8.25 months. The frequency of grade 3-5 treatment related adverse events was 29% with nivolumab and 10% with biomodulation. Overall survival (OS), the secondary endpoint, was comparable in both treatment arms; biomodulation with a median OS (95% confidence interval) of 9.4 (6.0-33.0) months vs. nivolumab 6.9 (4.6-24.0), respectively; hazard ratio (95% confidence interval) of 0.733 0.334; 1.610;
= 0.4368. Seventy-five percent of patients in the biomodulation arm received rescue therapy with checkpoint inhibitors.
This trial shows that the biomodulatory therapy was inferior to nivolumab on PFS. However, the fact that OS was similar between groups gives rise to the hypothesis that the well-tolerable biomodulatory therapy may prime tumor tissues for efficacious checkpoint inhibitor therapy, even in very advanced treatment lines where poor response to ICi might be expected with increasing line of therapy.
Burkitt leukemia (BL) represents a highly aggressive lymphoma characterized by proliferation rates of around 100%, and a frequent spread into the central nervous system. If standard frontline ...chemotherapy fails, the prognosis is usually dismal, and reports on successful effective salvage therapy strategies for patients with relapsed/refractory BL are scant. Here, we report on a 40‐year‐old female patient who suffered an early relapse of BL three months after the completion of frontline chemoimmunotherapy. Strikingly, after only one cycle of R‐DHAP chemotherapy, the patient showed CR of BL enabling swift transition to a consolidating allogeneic stem cell transplantation. A 40‐year‐old previously healthy woman presented to the hospital with fatigue and incessant epistaxis, and a diagnosis of BL was made upon histological examination of a bone marrow biopsy. Treatment was initiated according to the GMALL 2002 B‐NHL/ALL protocol, which could induce complete molecular remission. Nevertheless, three months after chemotherapy, the patient exhibited BL relapse in the bone marrow, and on Fluorodeoxyglucose (FDG)–PET‐imaging. The relapse therapy was started with R‐DHAP, and after only one cycle, the patient once again entered complete remission (CR) paving the way for allogeneic stem cell transplantation. Unfortunately, the patient again relapsed five months after transplantation prompting salvage therapy with R‐DHAC and the execution of the second stem cell transplantation. However, one month after the second transplantation the patient presented with chemorefractory meningeosis leukemia resulting in the initiation of palliative care treatment. In summary, we report on rapid CR of relapsed BL after a single cycle of rituximab‐DHAP. Given a paucity of clinical trials on the treatment of patients with r/r BL, we intend to highlight the potential efficacy of rituximab‐DHAP as salvage therapy in those patients.
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