Expression of cdc25A and cdc25B proteins in thyroid neoplasms

Abstract

Cdc25B and cdc25A phosphates are prominent stimulators of cell cycle progression and recent studies have also suggested their oncogenic roles. To elucidate the role of these proteins in thyroid neoplasms, we immunohistochemically investigated their expression, and neither protein was expressed in normal follicular cells. Cdc25B was frequently overexpressed in follicular adenoma and minimally invasive follicular carcinoma, but the incidence was significantly lower in widely invasive follicular carcinoma. Furthermore, the cdc25B expression level significantly decreased with the dedifferentiation of thyroid carcinoma. Cdc25A overexpression was observed in high incidences in all types of thyroid neoplasms. These results suggest that cdc25B and cdc25A play oncogenic roles in thyroid follicules and that cdc25B works predominantly in the early phase of the progression of thyroid carcinoma, whereas cdc25A plays a fundamental role in the development of thyroid neoplasms.

Figure 1

Immunostaining of cdc25B. (A) cdc25B overexpression in minimally invasive follicular carcinoma (+++). (B) cdc25B overexpression in widely invasive follicular carcinoma with solid growth pattern (++). (C) cdc25 overexpression in papillary carcinoma (+++). (D) cdc25 was negative in undifferentiated carcinoma (−).

Figure 2

Immunostaining of cdc25A. (A) cdc25A overexpression in cytoplasms of papillary carcinoma (+++). (B) cdc25A overexpression in cell nuclei of undifferentiated carcinoma (+++). (C) cdc25A overexpression in cytoplasms and cell nuclei of follicular adenoma (+++). Scale bars: 150 μm.