The Immunohistochemic Expression Of DACH1 And Its Clinical Significance In Papillary Thyroid Carcinoma And Hashimoto's Thyroiditis

Background and Objective: DACH1 is the analog of Drosophila dachshund gene in vertebrate, it is inhibited oncogene-mediated oncogenesis, blocking cancer epithelial cell DNA synthesis , colony formation, growth in Matrigel and tumor growth in mice . The role of DACH1 gene expression in papillary thyroid carcinoma and Hashimoto's thyroiditis was unknown. Our experiment is in order to investigate the immunohistochemic expressions of DACH1 in the tissues of the papillary thyroid carcinoma, the Hashimoto's thyroiditis and the nodular goiter, to explore the relationship between their expressions and the carcinogenesis and development of the papillary thyroid carcinoma.Methods: 30 cases of papillary thyroid carcinoma, 10 cases of Hashimoto's thyroiditis and 10 cases of nodular goiter were involved. Immunohistochemic SABC method was used to detect the expression of DACH1. 30 cases of papillary thyroid carcinoma were divided into 5 subgroups according to clinical features such as the size of tumor, with metastatic lymph nodes or not, age and sex. The correlations of the expressions of DACH1 with the clinical pathological parameters of the papillary thyroid carcinoma were analyzed.Results: (1) The immunohistochemic expression of DACH1 in papillary thyroid carcinoma and nodular goiter is orientated as the cytomembrane and cytoplasm. The positive rate of DACH1 is 76.7% in papillary thyroid carcinoma, notably higher than that in nodular goiter, later is 30% (P<0.01). (2)The positive rate of DACH1 is 60% in Hashimoto's thyroiditis, also higher than that in nodular goiter (P<0.01).(3)The positive rates of expression of DACH1 protein in papillary thyroid carcinoma with lymph nodes metastasis was 89.5%, while it was 54.5% in group of without lymph nodes metastasis. The differences are significant (P<0.05).Conclusions: The DACH1 protein is immunohistochemic overexpressed in papillary thyroid carcinoma and Hashimoto's thyroiditis. There is no obvious relationship among age,sex,the size of tumor and TNM of the positive expression of DACH1,but there is obvious relationship between the degree of infiltration and metastasis of lymph node, indicating that DACH1 may play a role in the carcinogenesis and development of papillary thyroid carcinoma.