Evaluation of the expression of Survivin-2α splice variant as a molecular marker in thyroid cancer

Thyroid carcinoma is the most common endocrine malignancy. Considering highly heterogenous nature of tumoral and non-tumoral thyroid nodules from pathological point of view and also in regard to absence of appropriate molecular markers, extensive efforts have been made to find a molecular tumor marker for specific diagnosis of thyroid tumors. Recent attention has been paid to Survivin, a new member of the Inhibitor of Apoptosis Protein Family (IAP), as a new molecular marker in cancer. Studies have been demonstrated that Survivin and its splice variants have different expressions in cancerous tissues compared to normal tissues. In this study the expression of Survivin-2α splice, one of the newest Survivin variants, was evaluated in thyroid cancer as a molecular marker. Tissue samples were collected from 77 thyroid specimens including 49 tumoral, 14 nontumoral and 14 tumor margin samples. The expression of Survivin-2α was studied by Hemi-Nested RT-PCR method. Expression of Survivin-2α splice was the highest in surgical margin samples compared to non-tumoral and tumoral samples. The lowest expression was that of tumoral samples. Our data demonstrated the expression of Survivin-2α in thyroid tumors. Although the expression of surviving-2α splice variant in tumoral cells was lower than that of tumor margins, it did not show a significant difference. Therefore it seems likely that it does not have a special role in the progression of tumor and development of abnormal nature of the cells. According to the results of this study, it can be concluded that the different expressions of 2α in these groups can not be an appropriate criterion for distinguishing tumors from non-tumoral lesions of thyroid gland.