Western blotting analysis for malignant lymphoma and stomach cancer antigens from carcinogen-transformed Bloom syndrome cells.

Membrane antigen (glyco-) proteins associated with malignant lymphoma (ML) and stomach (ST) cancer were collected from a carcinogen-transformed Bloom syndrome (BS) B-lymphoblastoid cell line by means of the panning protocol, in which antigen cell clones which specifically react with antibodies in ML and ST cancer sera were separated on polystyrene dishes coated with IgG. Gel electrophoresis and Western blotting (WB) analyses demonstrated that antigens which characterize ML and ST cancer gave a single band (ML, 97 kDa; ST, 118 kDa) and did not cross-react with sera of other cancer patients or with normal sera. The present WB procedure may be useful for diagnostic purposes. The amino acid sequence of the ML antigen band (97 kDa) had 76.9% (in 13 sequences) homology to that of the variable region of the immunoglobulin (Ig) heavy chain (IgVH) at the N-terminal end, while the sequence of the ST (118 kDa) cancer antigen had little homology to IgVH.