RESUMO
<p><b>OBJECTIVE</b>To investigate the mRNA expressions of RASSF1A, Galectin-3 and TPO in papillary thyroid carcinoma and some other thyroid benign lesions, and evaluate their diagnostic significance.</p><p><b>METHODS</b>Reverse transcription polymerase chain reaction (RT-PCR) was used to detect the mRNA expression of RASSF1A, galectin-3 and TPO in the samples from 73 cases, including 23 cases with papillary thyroid cancer, 16 with nodular goiter, 29 with thyroid adenoma and 5 with Hashimoto's disease.</p><p><b>RESULTS</b>A statistically significant difference in the mRNA expression of RASSF1A, Galectin-3 and TPO was observed between papillary thyroid carcinoma and follicular benign lesions (P<0.05). However, there was no significant difference among various kinds of benign lesions (P>0.05). A negative correlation of the expression of RASSF1A and Galectin-3 mRNA was found between thyroid benign lesions and malignant ones (P = 0.000). While the mRNA expression of RASSF1A and TPO was positively correlated between benign and malignant lesions (P = 0.028).</p><p><b>CONCLUSION</b>Loss of expression of RASSF1A and TPO mRNA but high expression of Galectin-3 mRNA in papillary thyroid carcinoma are common. Therefore, the products of these three genes may be closely related to the development of thyroid papillary carcinoma, and may be used as useful markers in differential diagnosis of papillary thyroid carcinoma from the benign lesions. The results are more reliable if this detection method is used in combination with other techniques.</p>