[Immunohistochemical study on oncogene product ras p 21 in thyroid carcinoma]

The oncogene product ras p 21 was detected by an immunohistochemical procedure in 132 cases of thyroid carcinoma and 14 cases of normal thyroid. In addition, semiquantitative analysis using percentage of positive cells and a serially diluting test of the primary antibody were performed in papillary and follicular carcinoma, and its non-neoplastic counterparts. Papillary carcinoma showed identical results in the immunostaining and semiquantitative analysis between minute and advanced carcinoma. Papillary and follicular carcinoma exhibited significantly increased expression of ras p 21 in the cytoplasm, although the former showed much more enhanced expression of ras p 21 than that in the latter. The immunostaining for ras p 21 in papillary carcinoma differed clearly from non-neoplastic counterparts in which ras p 21 expression was moderately enhanced, although this difference was statistically disappeared between follicular carcinoma and its non-neoplastic counterparts. However, non-neoplastic tissue located close to these neoplasms showed more increased immunostaining for ras p 21 than that observed in the thyroid tissues remote from the neoplasm, and in normal thyroid. Squamous cell, anaplastic and medullary carcinoma demonstrated non or poor expression of ras p 21. These results suggested that ras p 21 had some effects on papillary and follicular carcinoma, and the effects of oncogene product on the neoplasm and non-neoplastic counterparts differed considerably depending upon a histological type of thyroid carcinoma.