Increased expression of a 38kd cell-surface glycoprotein MH99 (KS 1/4) in oral mucosal dysplasias

A "window of expression" of a 38-kD cell-surface glycoprotein MH99 (KS 1/4 antigen) has been observed in dysplastic oral tissues using an MH99-specific monoclonal antibody. It appeared that expression of this epitope increases from baseline levels in normal oral epithelium to that of high levels in mild, moderate and severe dysplasia. In invasive squamous cell carcinoma, relatively low levels of expression were observed. In contrast, high levels of expression were demonstrated in basal cell carcinomas. Antibody reactivity could clearly distinguish between the margins of histologically normal and dysplastic tissues. It is envisaged that the expression of this cell-surface glycoprotein, which is possibly related to nidogen, a matrix-adhesion molecule with receptor-like function, could be used in monitoring progression or regression of these lesions and assessment of surgical excision margins. It could also be useful in in vivo and in vitro investigations into molecular changes underlying the formation of dysplastic lesions.