Immunohistochemical and immunoelectron microscopic studies of oral cancers using mouse monoclonal antibodies against human oral squamous cell carcinoma

Abstract

Human squamous cell carcinoma(SCC) tissues were examined immunohistochemically and with immunoelectron microscopy to localize the cellular antigen of SCC. The reactions of the mouse monoclonal antibodies(MoAbs) E8 and P54 produced against this human oral neoplasia were investigated. Both formalin-fixed, paraffin-embedded sections, and unfixed, fresh-frozen sections were used in the experiments. At low magnification light microscopy the stained reaction products of both antibodies were observed over the entire circumference of the cell membrane of both the non-neoplastic and neoplastic squamous cells. Under high magnification light microscopy, and with electron-microscopy, the two antibodies were found to react in different areas of the cells. The E8 antibody reacted with the entire cell membrane circumference of both non-neoplastic and neoplastic cells, and granularity was observed in the reaction products of the cytoplasm. The P54 antibody reacted with areas of the cell membrane adjacent to the desmosomes of both non-neoplastic and neoplastic cells. This reaction was stronger in the neoplastic cells showing up as a patch-like structure in the cell membrane. These results indicate that electron microscopy and high magnification light-microscopy are necessary when examining cell membrane staining of monoclonal antibody reactions, and that the cell membrane antigenicity of neoplastic cells appears to be stronger and more widespread than that of non-neoplastic cells.