Analysis of a human osteogenic sarcoma antigen and its expression on various human tumour cell lines

Mesenchymal specificity of three new monoclonal antibodies generated to the osteosarcoma cell line 4444T

We have generated three murine monoclonal antibodies to the new human osteosarcoma cell line 4444T. Analysis of their binding patterns to tumor cell lines, normal human tissues, and surgical tumor specimens indicates that the antibodies recognize a subset of human sarcomas and stromal tissues but fail to react with carcinomas or normal human epithelial tissue. These mesenchyme-specific monoclonal antibodies bind to antigens in the extracellular matrix. One antibody is specific in its binding to the muscularis arteriosus. We expect these antibodies to aid in the identification of sarcomas and to extend our knowledge of the components of the extracellular matrix and its interaction with tumors.

Osteosarcomas and chondrosarcomas of the jaws: immunohistochemical correlations

Clinical, microscopic, and immunohistochemical characteristics of 17 jaw sarcomas are reported. Histologic subtypes included chondroblastic (five), fibroblastic (five), osteoblastic (three), telangiectatic (one), parosteal (two), and chondrosarcoma (one). Reactivity for all antigenic markers in decalcified tissue was judged to be comparable to nondecalcified tissue. All neoplasms were nonreactive for muramidase and leukocyte common antigen. alpha-1 Antichymotrypsin and HLA-DR immunoreactivity was found focally. Positive S-100 staining was found predominantly in chondrocytes. All tumors were positive for vimentin. Cells in focal zones of cartilage were positive for keratin. No distinctive pattern emerged relative to clinical recurrence and histologic subtype or immunotype. Leukocyte common antigen determinations were useful because they distinguished between neoplastic and inflammatory cells. S-100 protein stains helped in the subclassification of chondroblastic osteosarcoma, and vimentin stains confirmed mesenchymal origin. Cross-reactive staining of cartilage with keratin antibodies was regarded as a possible diagnostic pitfall.

Patterns of reactivity of the monoclonal antibody 791T/36 with different tumour metastases in the liver

Reactivity of the monoclonal antibody 791T/36 with secondary malignant deposits has been investigated in frozen sections of 74 human liver biopsy specimens. There was no reactivity with hepatocytes but in some instances binding to fibrous tissues and in one case to portal tract lymphocytes was observed. Sections from 9 biopsy specimens contained malignant deposits. In seven of these 791T/36 bound either to malignant cells or to pseudoacinar contents (3 colorectal adenocarcinomas; 1 probable pancreatic adenocarcinoma; 1 medullary cell carcinoma of thyroid; 1 oat cell carcinoma of bronchus and 1 deposit of nodular sclerosing Hodgkins Disease). Two undifferentiated tumours (1 gastric adenocarcinoma and 1 oat cell bronchial carcinoma) showed no antibody binding. The histological pattern of reactivity previously reported with primary tumours appears to be similar in secondary deposits. A wider range of tumours than recognised hitherto binds 791T/36. Whether the binding to fibrous tissue seen in some instances is sufficient to cause diagnostic uncertainty when 791T/36 is used for scanning requires further investigation.

Application of markers in the diagnosis of soft tissue tumours

In this review we describe the application of markers which are useful for the diagnosis of soft tissue tumours in paraffin sections. Detection of intermediate filament proteins appears to be most useful for first screening of these neoplasms because all, except neuroblastomas, express vimentin; cytokeratin is expressed in synovial sarcomas, epithelioid sarcomas and mesotheliomas; desmin in myogenic tumours and glial fibrillary acidic protein in astrocytomas and gliomas. Tissue-specific markers are: factor VIII--related antigen-endothelial cells; myoglobulin and skeletal muscle myosin--skeletal muscle cells; neuron specific enolase--neurons and cells of the APUD systems; and leukocyte-associated antigen--leukocytes. Markers which are present in a variety of cell types and therefore do not serve as tissue-specific markers are; S-100 proteins, alpha-1-antichymotrypsin, creatine kinase M and actin. The S-100 antigens have been detected in melanomas, granular cell tumours, chondrosarcomas and in some schwannomas and liposarcomas. Alpha-1-antichymotrypsin has been found in fibrohistiocytic and 'true' histiocytic tumours and creatine kinase M and actin in myogenic tumours. No specific markers have, as yet, been described for fibrosarcomas, Ewing's sarcomas and hemangiopericytomas.