| Abstract: | A new series of monoclonal antibodies (Span 1-7) was produced by immunizing mice with SW 1990 human pancreatic cancer cells. Span 1-4 antibodies (Ab) reacted with 4-5 of 8 pancreatic cancer cell lines tested and with 5-6 of 9 colon cancer cell lines and some lung cancer cell lines. Span 1-4 antigens (Ag) were detected not only on cell surface but also in cultured spent medium of SW 1990 cells by ELISA. They were also found in the fractions of a cesium chloride gradient of SW 1990 xenograft homogenates which have the highest molecular weight, density and carbohydrate content. Their immunoreactivity is dependent upon sialic acid because prior digestion with neuraminidase abolished their immunoreactivity. Span 5,6,7 Ab reacted with only 3 of 8 pancreatic cancer cell lines tested and did not reacted with any other cell lines such as colon cancer, lung cancer and melanoma. The epitopes which were recognized by Span 5,6,7 Ab did not contain sialic acid. These results suggest that Span 1-4 Ab has potential application in the detection of gastrointestinal cancers and that Span 5,7 may be useful to detect the origin which is unknown by using immunohistochemistry method for metastatic lesions. |
