Establishment and characterization of a spontaneously immortalized myofibroblast cell line derived from a human liver angiosarcoma

Background/Aim: Fibrosis and/or cirrhosis are present in the precursor stag es of most liver cancers, However, little is known about the reciprocal int eractions of fibroblasts, mainly responsible for fibrosis, and the other li ver cells, We report here the isolation of a new liver myofibroblast cell l ine from a human liver angiosarcoma and its characterization. Methods: The cells were isolated by the explant technique and characterizat ion was performed, on one hand, using immunohistochemical and ultrastructur al analysis and, in the other hand, by determining their karyotype, ras and p53 status and their tumorigenic properties. Results: To date, the cells have undergone approximately 170 population dou blings and are still proliferating. Immunohistochemically, they were negati ve for desmin, smooth muscle myosin, cytokeratin 19 and von Willebrand fact or, positive for vimentin and alpha-smooth muscle actin, with an important deposition of fibronectin around the cells. Ultrastructure showed particula rly cytoplasmic microfilament bundles. Their chromosome number ranged from 38 to 168 with a binodal population, near diploid and hypotetraploid, No mu tations were found in codons 12, 13 or 61 of Ha-, Ki- and N-ras genes but a homozygous missense mutation in codon 179 (CAT-->CTT) was detected in the p53 gene, They were unable to form foci in soft agar or tumors in nude mice , Conclusions: Taken together, these results show that these cells, called BM 2.2.1, exhibited typical myofibroblast-like features, Although they contai ned a karyotype suggestive of tumoral cells and a homozygous mutated p53 ge ne, they were not tumorigenic, The nature of these cells and the abnormalit ies of the p53 gene and the karyotype, suggest that: i) they were a compone nt of the tumor stroma, and ii) they could have been involved in angiosarco ma development. Thus, this cell line may be valuable for the study of cellu lar interactions in liver carcinogenesis.