Evaluation of the expression of survivin-3b and survivin-3α, the novel splice variants, as diagnostic tumor markers in thyroid cancer

Survivin is a new member of inhibitor of apoptosis protein family (IAP) that plays an important role in the regulation of cell cycle and inhibition of apoptosis. Distinct expression of this gene in tumoral cells versus normal cells introduces it as the fourth major transcriptome in cancers. Thyroid carcinoma is the most common endocrine malignancy. Considering the highly heterogeneous nature of tumoral and non-tumoral thyroid nodules from the pathological viewpoint and also in regard to the absence of appropriate molecular markers، extensive efforts have been made to find a specific molecular tumor marker for diagnosis of thyroid tumors. Studies have been demonstrated that the expression pattern of survivin and its splice variants was different in cancerous tissues compared to normal tissues. In this study we evaluated expression of survivin-3b and survivin-3α، the novel survivin splice variants، as diagnostic markers for thyroid cancer. This was a descriptive study. 77 thyroid specimens; including 49 tumoral، 14 non-tumoral and 14 tumor margin samples were collected and expression of survivin-3b ands-3α was investigated by hemi-nested RT-PCR method. Tumoral samples showed the highest expression of survivin-3b and survivin-3α and the lowest expression was detected in the specimens of tumor margins. In this study we demonstrated the expression of survivin-3b and survivin-3α in thyroid tumors for the first time. In conclusion significant expression of survivin-3b and survivin-3α splice variants in tumoral cells shows their roles in thyroid cancer progression and their efficiency as molecular markers for detection and classification of tumoral and non-tumoral thyroid nodules.