Bone Abstracts

Chondrosarcomas are cartilage-forming, poorly vascularized tumors. With an estimated annual incidence of 1 in 200 000, they represent the second malignant primary bone tumor of adults after osteosarcoma. These tumors are resistant to chemotherapy and radiotherapy, surgical excision remaining the only therapeutic option. However, very few cell lines and animal models are available, and the mechanisms behind their chemoresistance remain largely unknown. Our goal was to establish...

Osteosarcoma is the most common primary malignant bone tumor, characterized by osteoid production and/or osteolytic lesions of bone. Despite recent improvements in chemotherapy and surgery, the problem of non-response to chemotherapy remains and constitutes a poor prognosis parameter. Consequently new therapeutic strategies aim to improve the overall rate of survival. The present work investigated the therapeutic interest of a dual phosphatidylinositol-3-kinase (PI3K)/mammalia...

Introduction and objective: Despite recent improvements in therapeutic management of osteosarcoma, ongoing challenges in improving the response to chemotherapy warrants the development of new strategies to improve overall patient survival. Among new therapeutic approaches, heat shock protein (HSP) 90 is a molecular chaperone involved in the maturation and stability of various oncogenic proteins leading to tumor cells survival. In this study, we assessed the in vitro a...

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Despite recent improvements in therapeutic management of osteosarcoma, ongoing challenges in improving the response to chemotherapy warrants new strategies still needed to improve overall patient survival. Among new therapeutic approaches, zoledronic acid represents a promising adjuvant molecule to chemotherapy to limit the osteolytic component of bone tumors. However, zoledronic acid triggers the elevation of heat shock proteins (Hsp), including Hsp27 and clusterin (CLU), whi...

It has been established that disturbances of intracellular signaling pathways strongly contribute to the oncologic process. Indeed, phosphatidylinositol-3-kinase (PI3K) became a key target in cancer therapy, due to its high frequency of mutation and/or gain of function of its catalytic subunits in cancer cells. In this context, we investigated the in vitro and in vivo effects of a new PI3Kα inhibitor, BYL719 (Novartis Pharma), on bone cells and its thera...

Osteosarcoma is the most common primary malignant bone tumor, characterized by osteoid production and/or osteolytic lesions of bone. A lack of response to chemotherapeutic treatments points out the importance of exploring new therapeutic ways. Imatinib Mesylate (Glivec, Novartis Pharma), a tyrosine kinase inhibitor, has been originally developed for the treatment of chronic myeloid leukemia. Several studies revealed that Imatinib Mesylate inhibits osteoclast differentiation th...

Objectives: The Brtl mouse, a unique model for the autosomal dominant forms of osteogenesis imperfecta was used to prove the feasibility of a lentiviral-shRNA-based strategy to improve collagen quality by targeting the mutant Col1a1 allele at the point mutation responsible for the causative substitution Gly349Cys. The ability to specifically suppress the mutant allele should convert the moderate Brtl outcome to the mild one caused by quantitative defect.<p class="...

Background: High doses of zoledronic acid (ZOL), one of the most potent inhibitors of bone resorption; is currently evaluated in a phase III clinical trial in Europe for the treatment of malignant pediatric primary bone tumors. The impact of such an intensive treatment on the craniofacial skeleton is a critical question in the context of patients with actively growing skeleton; in particular in the light of our previous studies evidencing that endochondral bone formation was t...