Wild-type p53 gene transfer resulted in cell cycle arrest, but not apoptosis of newly established human malignant fibrous histiocytoma cell line.

We established a human malignant fibrous histiocytoma (MFH) cell line, MFH-ToE, from a tumor originally developed in the right thigh of a 78-year-old woman. The original tumor histologically consisted of histiocytic, fibroblastic and giant cells. The tumor cells showed immunoreactivity for vimentin and alpha-1-antichymotrypsin, and were positive for acid phosphatase and non-specific esterase, being compatible with MFH. Although the histology of the heterotransplanted tumor into nude mice was similar to that of the primary MFH, the population of giant cells gradually decreased along with the culture passages. Cytogenetic analysis revealed a highly aneuploid nature with varying numbers of chromosomes from 71 to 140. Chromosome 17 showed monosomy and exon 6 to 8 of p53 gene was not amplified by PCR, implying absence of p53 function. Adenovirus vector-mediated wild-type p53 gene was successfully transfected into the MFH-ToE, which showed up-regulation of P53 and P21, as well as gradual up-regulation of Bcl-2 protein. The transfection resulted in cell cycle arrest, but not apoptosis of the MFH-ToE cells. These results revealed unique properties of the MFH-ToE, which might be useful in further studies analyzing pathological and biological characteristics of MFH.