Study On Expression And Biological Significance Of Pseudogene HMGA1L2 In Benign And Malignant Thyroid Lesions

Objective: Thyroid carcinoma represents the most common malignant endocrine tumor. Thyroid adenoma is the most common benign tumour, and thyroid follicular carcinoma is the second common malignant tumer, after thyroid papillary carcinoma. It is difficult for pathologist to diagnosis thyroid follicular carcinoma against thyroid adenoma. Former study showed that HMGA1 mRNA lever can be the marker for their differentiation. So study pseudogene HMGA1L2 mRNA level in benign and malignant thyroid lesions is the aim. And the biological significance expected to be find out.Methods: 50 cases of thyroid lesions were collected from archives of Department of pathology in Shihezi University School of Medicine from 1983~2005, including 12 cases of nodular goiter, 9 cases of thyroid adenoma, 15 cases of papillary carcinoma and 14 cases of thyroid follicular carcinoma. Total RNA was extracted by TRIzol from 10 sheets of paraffin-embedded and formalin-fixation tissues slices, which were cut into 5μm thick. Before RT-PCR total RNA was digested by DNase I. Chisquare test was applied by SPSS13.0.Results: The expression of HMGA1L2 mRNA was found in all 12 cases of nodular goiter, all 9 cases of thyroid adenoma and all 15 cases of papillary carcinoma. However, in 14 cases of thyroid follicular carcinoma, the frenquence of HMGA1L2 mRNA expression was 35.7%, which was significantly different from that in other types of thyroid lesions (P<0.05).Conclusion: This is the first report of mRNA expression of pseudogene HMGA1L2 in nodular goiter and thyroid tumors. It indicate that pseudogene HMGA1L2 expression analysis could be helpful in differentiation between follicular carcinoma and adenoma. Further studies are needed to determine its diferentational value and function in carcinoma genesis.