Phenotypic characterization of the human fibrous histiocytoma giant cell tumor (GCT) cell line and its cytokine repertoire.

The pleiotropic nature of malignant fibrous histiocytomas (MFH) is manifested as mixed cellular infiltrates consisting of myofibroblasts, histiomonocytes, and neutrophils. We detail in this report the phenotypic characteristics of the human fibrous histiocytoma giant cell tumor (GCT) cell line that establish its mesenchymal origin. The latter is underscored by the ability of GCT cells to express mRNA for transforming growth factor beta (TGF-beta) as well as both A and B chains of platelet-derived growth factor (PDGF). GCT cells also support the binding of CD34+ cells, but less efficiently than do normal marrow stromal cells. Since cytokines elaborated by MFH may mediate in part the recruitment of monocytes and neutrophils into tumor-infiltrated tissues, we have determined the cytokine repertoire of the GCT cell line, already known for its ability to elaborate colony-stimulating factors (CSFs) and interleukin-1 (IL-1). GCT cells express IL-1 alpha, IL-1 beta, IL-6, macrophage colony-stimulating factor (M-CSF or CSF-1), granulocyte-macrophage colony-stimulating factor (GM-CSF), granulocyte colony-stimulating factor (G-CSF), and IL-8. No detectable mRNA for IL-3, IL-4, IL-7, and tumor necrosis factor-alpha (TNF-alpha) was detected in GCT cells by polymerase chain reaction (PCR). Expression of cytokine mRNAs was responsive to agents such as dexamethasone (dex), 12-O-tetradecanoyl phorbol 13-acetate (phorbol diester or TPA), and TNF-alpha. Thus, this cell line provides a useful model for understanding the pathobiology of MFH and hematopoietic progenitor interactions with mesenchymal/stromal cells.