Navegando por Palavras-chave "in vitro assays"

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    C-kit expression in human osteosarcoma and in vitro assays
    (E-century Publishing Corp, 2011-01-01) Miiji, Luciana Nakao Odashiro [UNIFESP]; Petrilli, Antonio Sergio [UNIFESP]; Di Cesare, Sebastian; Odashiro, Alexandre Nakao [UNIFESP]; Burnier, Miguel Noel Nascente [UNIFESP]; Toledo, Silvia Regina Caminada de [UNIFESP]; Garcia, Reynaldo Jesus; Alves, Maria Teresa de Seixas [UNIFESP]; Universidade Federal de São Paulo (UNIFESP); McGill Univ; Ctr Hosp Afillie Univ Quebec
    Biologic agents targeting oncogenes have encourage researchs trying to correlate the role of tyrosine kinase in the pathogenesis of tumours. Osteosarcoma is a high grade aggressive neoplasm with poor survival. Our aim was to investigate c-kit immunoexpression, its prognostic relevance for patients with osteosarcoma, and the effect of imatinib mesylate (STI571) on proliferation and invasion of the human osteosarcoma cell line. A retrospective immunohistochemical study was performed on archival formalin-fixed paraffin-embedded specimens from 52 patients with high-grade primary osteosarcoma of extremities treated at the Pediatric Oncology Institute (IOP, GRAAC) and archived in the Department of Pathology, Federal University of Sao Paulo. Only pre-chemotherapy specimens were analyzed. Strongly stained cytoplasm and membrane cells were taken as positive. Human osteosarcoma cells from line MG-63 were incubated and the inhibitory effect of imatinib mesylate (STI571) on cell proliferation and invasion was studied. In 24 cases (46.15%), c-kit was expressed by the cells and c-kit-positive tumors exhibited lower necrosis post-chemotherapy. No correlation was found between c-kit expression and overall and disease-free survival. Imatinib mesylate decreased the rates of cell growth of osteosarcoma cells in low doses and invasion in high doses C-kit-positive tumors had worse response to chemotherapy and imatinib mesylate can play a role in blocking or decreasing the rate of growth of osteosarcoma cells, but not the invasive capacity of these neoplastic cells. These data suggested that imatinib mesylate could be a therapeutic target of strategies against osteosarcoma tumors. Further studies are necessary to confirm this indication.
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    Imunoexpressão do c-kit em Osteossarcomas Humanos: Correlação com parâmetros anátomo-patológicos, clínicos e testes in vitro
    (Universidade Federal de São Paulo (UNIFESP), 2009-05-27) Miiji, Luciana Nakao Odashiro [UNIFESP]; Alves, Maria Teresa de Seixas [UNIFESP]; Universidade Federal de São Paulo (UNIFESP)
    Purpose: To investigate the immunoexpression and its prognostic relevance of KIT in patients with osteosarcomas and the effect of Imatinib mesylate (STI571) on proliferation and invasion of human cell osteosarcoma line. Material and Methods: A retrospective immunohistochemical study was performed on archival formalin fixed paraffin-embedded tissue obtained from Department of Pathology of Federal University of São Paulo of 52 high-grade patients with primary osteosarcomas of extremities treated at the Instituto de Oncologia Pediátrica. Only pre-chemotherapy specimens were analysed. Strong cytoplasmic and membranous staining cases were taken as positive. The human cell line MG 63 was incubated and inhibitory effect of STI571 on cell proliferation and invasion was studied. Results: Twenty four cases (46,15%) expressed c-kit and tumours ckit positive had lower necrosis pos chemotherapy. No correlation was found between ckit expression and overall and disease free survival. STI571 inhibited the rates of cell growth of osteosaroma cells in low doses and invasion in high doses Conclusions: Tumours c-kit positives had worse response to chemotherapy and STI571 plays a role in blocking or slowing the rate of growth of osteosarcoma cells expressing ckit, but not the invasive capacity of these neoplastic cells. These data suggested that Imatinib Mesylate could be a therapeutic target of strategies against Osteosarcoma that express c-kit.