DETECTION OF KERATIN SUBTYPES IN ROUTINELY PROCESSED CERVICAL TISSUE - IMPLICATIONS FOR TUMOR CLASSIFICATION AND THE STUDY OF CERVIX CANCERETIOLOGY

We investigated the expression of keratin subtypes 7, 8, 10, 13, 14, 1 7, 18 and 19 in the normal cervix, in cervical intraepithelial neoplas ia (CIN) lesions and in cervical carcinomas, using a selected panel of monoclonal keratin antibodies, reactive with routinely processed, for malin fixed paraffin embedded tissue fragments. The reaction patterns derived for each keratin antibody were compared with known expression patterns of the various epithelia, previously examined in frozen tissu es. Although the reactivity of the antibodies was generally acceptable , considerable modifications to the manufacturers' staining instructio ns were often necessary. For some antibodies, which were previously th ought to be reactive with fresh frozen tissue only, we developed stain ing protocols rendering them reactive with routinely processed materia l. As with previous findings in frozen sections we observed increasing expression of keratins 7, 8, 17, 18 and 19 with increasing grade of C IN. In cervical carcinomas the differences in keratin detectability be tween the main categories were more pronounced than in frozen sections , probably due to fixation and processing. For routine pathology, kera tin phenotyping of cervical lesions may be of value in classification. The fact that keratin 7 was detected for the first time in reserve ce lls, and that this keratin was also found to be expressed in a conside rable number of CIN lesions and cervical carcinomas supports the sugge stion that reserve cells are a common progenitor cell for these lesion s.