Naoko Kudo

Establishment of novel human dedifferentiated chondrosarcoma cell line with osteoblastic differentiation

Dedifferentiated chondrosarcoma is a rare, highly malignant variant of chondrosarcoma in which a high-grade sarcoma coexists with a low-grade chondroid tumor. We herein review a case of dedifferentiated chondrosarcoma with an osteosarcoma omit component that occurred in the distal femur of a 38-year-old man. We established the cell line (NDCS-1) from a pleural effusion of the metastatic lung tumor. The cell line was characterized by a the G-banded karyotype, polymerase chain reaction (PCR) single-strand conformation polymorphism analysis, spectral karyotyping, and reverse transcriptase PCR (RT-PCR). The tumor exhibited complex karyotypes and a high frequency of chromosomal amplication with p53 mutation. This tumor revealed an osteoblastic and chondroblastic character in vitro and in severe combined immunodeficiency mice. The expression and phosphorylation of platelet-derived growth factor receptor-β, which seemed to play a major role in the malignant phenotype of chondrosarcoma, was confirmed by RT-PCR and Western blotting. To our knowledge, this is the first report of the establishment of a human dedifferentiated chondrosarcoma.

Congenital dermatofibrosarcoma protuberans with fibrosarcomatous and myxoid change

This report describes a case of congenital dermatofibrosarcoma protuberans (DFSP) with fibrosarcomatous (FS) and myxoid areas. Immunohistochemical results showed that tumour cells in ordinary DFSP areas were diffusely positive for CD34, whereas in the FS and myxoid areas, few tumour cells were positive for this antigen. Ki-67 positive tumour cell numbers were greater in the FS (11.8%) and myxoid areas (19.8%) relative to ordinary DFSP areas (2.2%). Reverse transcription polymerase chain reaction and sequence analysis showed the presence of an identical COL1A1–PDGFB fusion transcript in ordinary DFSP (plaque-like area), FS, and myxoid areas of DFSP. These results indicate that the three components of DFSP have a common histogenesis. This study documents the first application of gene analysis involving the myxoid area of DFSP.