Expression of oncofetal fibronectin mRNA in thyroid anaplastic carcinoma

Background: Oncofetal fibronectin (onfFN) is a fetal protein, the expression of which is observed in papillary thyroid carcinomas but not in follicular tumors or in normal thyroid. Its expression in anaplastic thyroid carcinoma (ATC), however, has not been clarified, since only a few cases had been examined in previous studies. Methods: We examined the expression levels of onfFN mRNA in ATC tissues and cell lines derived from ATC by real-time quantitative reverse transcription-polymerase chain reaction (PCR) and in situ hybridization. Results: Increased expression of onfFN mRNA was observed in all cases of ATC regardless of the type of accompanying differentiated carcinoma and five of six ATC cell lines. Furthermore, expression of onfFN mRNA was observed in the majority of ATC cells in all six tissues examined by in situ hybridization. Conclusion: These results confirm that expression of onfFN mRNA characterizes not only papillary thyroid carcinoma but also ATC. onfFN mRNA or protein may be a useful marker to identify anaplastic carcinoma cells and may be considered as an optimistic target in molecular-based therapy of ATC.