Characteristics of in vitro passaged cells derived from a rat transplantable malignant fibrous histiocytoma.

Abstract

Morphologic and functional characteristics were investigated on in vitro passaged cells (MT-P) derived from a rat transplantable malignant fibrous histiocytoma (MFH-MT). There were spindle, polygonal, and giant cell types in MT-P. Ultrastructurally, the polygonal and giant cells had the abundant cytoplasm with many lysosomes and processes, whereas the spindle cells possessed smooth cell surface and a small number of lysosomes in their cytoplasm. Immunorosette formation for Fc- and C3-surface receptors and phagocytic activity were demonstrated in 10-20% of MT-P. MT-P were positive for acid phosphatase, nonspecific esterase and alkaline phosphatase. Chromosomes counted in 100 MT-P ranged from 32 to 100 with two peaks of 64 and 76. Tumors induced in syngeneic rats by inoculating MT-P showed variable histologic patterns. They were composed partly of histiocytic cells arranged in a compact sheet. Fibroblastic cells often arranged in a storiform pattern or were supported by myxoid matrix. Osteosarcoma-like structures were occasionally found in the tumors. These results suggest that MFH-MT is heterogeneous, although some cells constituting the tumors have histiocytic markers.

The localization and distribution of cells labeled by a somatic stem cell-recognizing antibody (A3) in rat colon development; possible presence of a new cell type forming the intestinal stem cell niche

“…Antibodies specific to certain cell types are very useful to pursue the kinetics and participation in genesis and lesion development of cells. To investigate the histogenesis of rat malignant fibrous histiocytoma (MFH), A3 was generated as a monoclonal antibody against MT-8 cells as the antigen 1 , 2 , 3 , 4 . MT-8 cells were established from a spontaneous rat MFH and regarded as primitive pluripotential mesenchymal cells that may be capable of differentiating into well-differentiated mesenchymal cells, such as adipogenic, osteogenic, and myofibrogenic cells 4 , 5 .…”