Examination of Oral Cancer Tissue for the Presence of the Proteins ICP 4, ICP 5, ICP 6, ICP 8, and g8 of Herpes Simplex Virus Type 1 1,2

ABSTRACT-Although patients with oral cancer have increased levels of antibody to herpes simplex virus type 1, the origin of the antigenic stimulation remains unknown. We have therefore looked for proteins of herpes simplex in oral squamous cell carcinomas by staining frozen sections with monoclonal antibodies to the pro-teins ICP 4, ICP 5, ICP 6, ICP 8, and gB. No staining was seen of the tumor cells of any of 11 oral cancer cases or of the epithelium of 29 other oral lesions, which included cases of leukoplakia, lichen planus, and aphthous ulcers. Frequent staining of mast cells was seen in the connective tissue associated with oral cancer when ascitic fluid was used as the source of monoclonal antibody, but such staining was not seen when the precipitated IgG fraction was used.-JNCI 1986; 76:371-374. Two human cancers have been associated with the HSV by serologic studies. Cervical cancer is associated with raised levels of antibody to HSV-2 (1), and RNA and proteins of HSV-2 have been demonstrated in the tumor cells (2-6). Oral cancer is associated with raised levels of IgA and IgM antibody to some proteins of HSV-l (7-9), and RNA of HSV-l has been demon-strated in some oral tumors (10). The raised levels of antibody in patients with oral cancer are presumably due to expression of antigens of HSV-I at some site, but proteins of the virus have not been detected in oral tumors to date. Therefore, we have used the sensitive ABC technique in conjunction with monoclonal anti-bodies to certain proteins of HSV-I to look for virus proteins in the tumor cells. METHODS Patients.-Biopsy specimens were obtained from pa-tients who were attending the Oral Medicine Clinic o