Establishment and characterization of cell line TNMY1 derived from human malignant fibrous histiocytoma.

Although malignant fibrous histiocytoma (MFH) is one of the most common soft tissue sarcomas, its pathogenesis remains unclear. In this study, a cell line derived from human MFH, TNMY1, was established from a metastatic chest-wall lesion of a 60-year-old woman with MFH. The TNMY1 cell line was passaged 95 times, and it still retained the biological characteristics of the original tumor. TNMY1 consists of spindle-shaped cells and pleomorphic cells associated with multinucleated giant cells. Immunohistochemical studies showed that the spindle-shaped and pleomorphic cells were positive for vimentin, CD68 and alpha-smooth muscle actin, but negative for epithelial membrane antigen, desmin, muscle actin, alpha-sarcomeric actin, myoglobin, lysozyme and S-100 protein. The cells expressed collagen types I, III and V. These results indicate that MFH may originate from mesenchymal stem cells with the potential to differentiate into either fibroblasts or histiocytes. An elevated level of collagen type V mRNA expression is considered to support a diagnosis of MFH.