RESUMO
Medulloblastoma (MB) is the most common type of brain tumor affecting children. These tumors are a significant cause of childhood mortality and morbidity, and more effective and less invasive treatment options are urgently required. To achieve these aims, it will be critical to develop a more comprehensive understanding of the molecular pathogenesis of MB. At present, there are relatively few well-characterized MB cell lines available to the research community for the study of MB molecular and cellular biology. Here we present the case reports of two children diagnosed with classic and desmoplastic MB, and describe the characteristics of two new MB cell lines derived from these individuals. A number of genes encoding components of the sonic hedgehog (SHH) and WNT pathways were up-regulated in the desmoplastic relative to the classic MB cell line consistent with aberrant activation of these pathways in desmoplastic MB. These cell lines represent an additional resource for the analysis of diverse aspects of MB biology.
Assuntos
Neoplasias Cerebelares/genética , Neoplasias Cerebelares/patologia , Meduloblastoma/genética , Meduloblastoma/patologia , Linhagem Celular Tumoral , Neoplasias Cerebelares/terapia , Criança , Pré-Escolar , Evolução Fatal , Humanos , Masculino , Meduloblastoma/terapia , Células Tumorais CultivadasRESUMO
A recent publication described 5 unusual clear cell renal tumors with prominent smooth muscle stroma that were characterized only by immunostaining. We report 3 additional tumors composed of clear cell renal cell carcinoma intimately admixed with abundant smooth muscle stroma. Epithelial differentiation of the malignant clear cell components and smooth muscle differentiation of the benign spindle cell stroma was confirmed by the immunostaining profiles and by electron microscopy. Fluorescence in situ hybridization analysis of chromosome 3 showed loss of the entire chromosome in 2 cases and loss of 3p in the third case. We therefore interpret these tumors as unique low-grade variants of clear cell renal cell carcinoma that have induced a prolific metaplastic stromal reaction. Extensive tissue sampling and immunostaining are recommended to distinguish cases with an extensive smooth muscle component from morphologically similar but benign lesions including angiomyolipoma, leiomyoma, or mixed epithelial and stromal tumor of the kidney.
