SARG: a new human osteosarcoma cell line. Expression of bone markers and of major histocompatibility antigens.

A new cell line (SARG) was established from a human radiation-induced osteosarcoma (OSA). It showed an epithelial-like morphology with polymorphous and sometimes bizarre nuclei. SARG had an osteoblastic differentiation pattern: almost 100% of the cells were positive for alkaline phosphatase, type I and III collagens and osteonectin. The expression of class I HLA antigens was detectable even after 40 in vitro passages. The expression of MHC antigens was greatly increased after in vitro treatment with interferon gamma (IFN-gamma), whereas interferon alpha (IFN-alpha) and tumor necrosis factor alpha (TNF-alpha) increased the expression of class I antigens, but not of class II antigens. SARG was tumorigenic after subcutaneous injection in nude mice. Experimental metastases were never detected.