This thesis describes the effects of shortterm fasting on chemotherapy outcome in patients with breast cancer and the IGF-1 and insulin pathway as a target for cancer therapy and as a biomarker for... Show moreThis thesis describes the effects of shortterm fasting on chemotherapy outcome in patients with breast cancer and the IGF-1 and insulin pathway as a target for cancer therapy and as a biomarker for chemotherapy outcome.Preclinical research is evaluated, which shows that short-term fasting during chemotherapy is effective. The effects of short-term fasting in humans is not evident yet. Although the first small clinical studies of short-term fasting as adjunct to chemotherapy are promising in terms of decreased toxicity and enhanced efficacy, the exact mechanism and effects are not established yet. More studies and a longer follow-up are needed to prove this.Insulin-like growth factor 1 (IGF-1) and insulin are members of the IGF-1 pathway, which is involved in cell growth and proliferation. The effects of the IGF-1 pathway on chemotherapy outcome and the pathway itself as target for cancer therapy are described. The disappointing results of clinical studies of IGF-1R inhibitors may be caused by the complexity of the IGF-1R pathway. Lowering both insulin and IGF-1, perhaps with a short-term fasting intervention, serves as a possible target in cancer therapy. Show less
One of the main questions in Ewing sarcoma treatment is to identify low-risk patients that can be treated with less intensive treatment so that toxicity and the occurrence of long-term adverse... Show moreOne of the main questions in Ewing sarcoma treatment is to identify low-risk patients that can be treated with less intensive treatment so that toxicity and the occurrence of long-term adverse effects can be limited while still maintaining high cure rates or to identify those patients for whom treatment is expected to have limited benefit. Furthermore, to identify high-risk patients in which treatment needs to be intensified to improve outcome. Selection of risk groups and adjusted treatment allows for early decision making, will help to improve future outcomes and assists in clinical trial design. Additionally, treatment of Ewing sarcoma is multimodal and surgery, if feasible, is crucial for curative management. However, accurate detection and localization of tumor boundaries, especially in anatomical complex locations such as the pelvic is challenging. Inadequate surgical margins lead to a higher risk of local recurrence which has major impact on oncological outcome. Developments in intra-operative imaging, like CT-based navigation systems and near infrared (NIR)fluorescence guided surgery (FGS) make accurate defining and localization of surgical margins possible. They represent a whole new field of precision medicine and provide new treatment options for patients, thereby improving function outcome and healthcare quality. Show less
Ewing and chondrosaroma are two forms of primary bone cancer. The few clinical studies that are published in recent decades show disappointing results. With a 5 year survival of 10% for inoperable... Show moreEwing and chondrosaroma are two forms of primary bone cancer. The few clinical studies that are published in recent decades show disappointing results. With a 5 year survival of 10% for inoperable Ewing sarcoma and 2% for inoperable chondrosarcoma patients the outcome is poor. If a patient has not responded to standard treatment, they are often treated with combinations based on expert opinion of the treating physician. These treatment combinations have not been investigated in studies because of the small patient numbers which makes starting a study very difficult and time-consuming. One combination is of the chemotherapeutic agents etoposide with carboplatin or cisplatin. Analysis of the survival data of patients treated with these combinations shows that they are comparable to other standard treatment options. New non-chemotherapy treatment options are currently being investigated. Examples are the IGF-1R and PARP route. The current knowledge of both routes shows that disregulation causes malignant transformation and / or disease progression. Inhibition of these routes is therefore a possible treatment. In clinical studies, the results are not positive for all patients. This is due to incorrect patient selection and not being tested in combination with already used treatments. Show less
Ewing sarcoma is an aggressive primary malignant bone tumor with high degree of tumor vascularization and is the second most common sarcoma of bone in children and young adults. Patients... Show more Ewing sarcoma is an aggressive primary malignant bone tumor with high degree of tumor vascularization and is the second most common sarcoma of bone in children and young adults. Patients with disseminated disease at diagnosis or early relapse have a poor prognosis. To identify novel therapies and biomarkers for these patients we focused on the chemokines and chemokine receptors in Ewing sarcoma cells and their role its tumor microenvironment. CCL21 CXCL14, CXCR7 and the ratio between CXCR4-1 and CXCR4-2 have been identified as candidate prognostic markers, CCL21 immunotherapy as potential therapy and CXCR4 as potential therapeutic target in EWS. In addition, the presented peptide-based life cell imaging methods improve the ability to study CXCR4 cell membrane expression and dynamics qualitatively and quantitatively. This approach might be helpful for the measurement of anti-CXCR4 therapy efficacy. This work identified specific the chemokine signaling pathways that can be used to target Ewing sarcoma and its tumor microenvironment. Show less
Ewing sarcoma (ES) is a special type of bone cancer, first described by Dr. James Ewing in his paper __Diffusive endothelioma of bone__. Today Ewing sarcoma represents the second most common bone... Show moreEwing sarcoma (ES) is a special type of bone cancer, first described by Dr. James Ewing in his paper __Diffusive endothelioma of bone__. Today Ewing sarcoma represents the second most common bone cancer among adolescents and young adults. Contrary to the positive achievement in treatment of localized tumors, the long-term (5-years) survival for Ewing sarcoma patients with metastasis, however, remain below the 30% mark. In this thesis a report on experimental work aiming for a better understanding of the mechanisms underlying Ewing sarcoma metastasis is presented. Two distinct mechanisms are investigated: (1) a biochemical approach in which the initial steps in the CXCR4 signaling cascade are followed, and (2) a biophysical approach in which the guidance of Ewing sarcoma metastasis by the stiffness of their microenvironment is demonstrated. The results presented in this thesis provide deeper insights into the mechanisms controlling signaling of the chemokine receptor CXCR4 and into the role of the micro-environment in Ewing sarcoma cells behavior.Through various experimental approaches it was shown that both biochemical and biophysical guidance control how Ewing sarcoma develops into its distinct metastatic phenotype. Show less
Osteosarcoma and Ewing sarcoma are the most common bone cancers in children and young adults. Despite advanced surgical techniques and multi-drug chemotherapy, patients with recurrent, metastatic... Show moreOsteosarcoma and Ewing sarcoma are the most common bone cancers in children and young adults. Despite advanced surgical techniques and multi-drug chemotherapy, patients with recurrent, metastatic or chemotherapy-resistant disease have a poor outcome. Thus, novel targeted therapies are needed that combine potent and specific anti-cancer activity with limited toxicity toward normal tissues. The thesis is introduced by an outline of the biological properties of osteosarcoma and Ewing sarcoma, followed by an overview of cancer immunology and immunotherapy with the primary focus on innate immunity of human natural killer (NK) cells and macrophages. In the research chapters, cellular interactions of NK cells and macrophages with bone tumor cells are characterized in order to achieve favorable effects on anti-cancer immune cell functions. It is demonstrated that the anti-cancer potential of especially NK cells but also macrophages can be enhanced and directed to the bone tumor cells. It is discussed that the modulation of tumor__immune cell interactions may help to design novel immunotherapeutic approaches to harness anti-cancer functions of innate immune cells against osteosarcoma and Ewing sarcoma. Show less
In this thesis, we report on various aspects of tumor - host (immune) interactions in Ewing sarcoma patients with the aim to obtain leads for immunotherapeutic or targeted treatment strategies. We... Show moreIn this thesis, we report on various aspects of tumor - host (immune) interactions in Ewing sarcoma patients with the aim to obtain leads for immunotherapeutic or targeted treatment strategies. We demonstrate a key role for interferon gamma (IFNg) in enhancing both Ewing sarcoma immunogenicity and susceptibility to cytotoxicity. An (endogenous) pro-inflammatory tumor microenvironment consisting of cytotoxic T-lymphocytes and IFNg-inducible chemokines provides prognostic benefit. Moreover, despite evidence for immunologic pressure in selection of HLA class I loss variants, intact IFNg-inducibility of the HLA class I antigen processing machinery emphasizes the significance of a pro-inflammatory microenvironment for initiation/ execution of adaptive anti-tumor immunity. Pre-clinical support for the potential of adoptive cell transfer therapies, in particular combinatorial natural killer cell-based therapy, is provide d. Sensitization of Ewing sarcoma by conventional or targeted therapies, including histone deacetylase inhibitors, combined with cytokine activation of natural killer cells enhances anti-tumor responses and overcomes both intrinsic functional natural killer cell defects as well as cross-resistance of chemotherapy-resistant Ewing sarcoma to natural killer cells. Finally, due to a crucial role of the CXCR4-CXCL12 axis in Ewing sarcoma progression, disruption of this axis by a CXCR4-specific antagonist may represent a promising treatment option for patients with Ewing sarcoma. Show less
Non-haematogenic tumours arising primarily in the bone are rare. They are classified based on their histomorphology. Within the osteofibrous group the spectrum ranges from benign, exclusively... Show moreNon-haematogenic tumours arising primarily in the bone are rare. They are classified based on their histomorphology. Within the osteofibrous group the spectrum ranges from benign, exclusively fibrous lesions to high-grade osteosarcoma. These osteofibrous tumours show histological variability in a given entity as well as similarities between entities. The purpose of this thesis was to reveal the meaning of the phenotypic spectrum of osteofibrous tumours. In retrospect, the histological subtype of osteosarcoma is a predictive factor for response to chemotherapy, late relapse and risk of a hereditary cancer syndrome, but not for survival. However, the poor histological response of chondroblastic osteosarcomas to neo-adjuvant chemotherapy did not translate in a lower survival rate. On the other hand, overlapping histological and/or clinical parameters between certain tumour entities such as for example adamantinoma and Ewing sarcoma, and desmoplastic fibroma of bone and desmoid type fibromatosis of soft tissue, does not justify to classify these tumours as part of one disease entity as was demonstrated in this thesis. Thus, the correct classification, reclassification of known entities on new insights and sub-classification on phenotypic differences, when related with biological behaviour, has implications for clinical practice and disease management, and contributes to optimal patient care. Show less
