The expression and clinical significance of Galectin 8 in papillary thyroid cancer

To study the expression of Gal-8 in papillary thyroid cancer, and to explore the relationship between Gal-8 and clinical characteristics of papillary thyroid cancer (PTC) and mean vessel density (MVD). The relationship of MVD among Thyroid diseases was also studied. The relative mRNA expression of Gal-8 in 15 PTC and 15 benign thyroid disease (BTD) were analyzed using real time qRT-PCR (Quantitative Reverse Transcription PCR). The protein expression of 70 Thyroid diseases included 33 PTC (having corresponding normal tissues), 15 follicular adenoma (FA), 10 multi nodular goiter (MNG), 4 medullary carcinoma (MC) and 8 normal thyroid (NT) were analyzed by immunohistochemistry (IHC). MVD was measured focusing on hotspot area of highest vascularization of tumor. The relative mRNA expression of Gal-8 in PTC was 2.6 times higher than BTD. Compared with the BTD and NT, the expression of Gal-8 protein in PTC was significantly increased (P < 0.001). The sensitivity and specificity of Gal-8 in PTC were 96% and 62%, respectively. Gal-8 protein expression was associated with lymph node metastasis in PTC, suggesting that Gal-8 may be transferred from the cytoplasm to the nucleus (P < 0.009) as the tumor metastasized. The expression of Gal-8 was significantly stronger in the low TNM stage (I/II) than in the high TNM stage (III/IV) of thyroid cancer. MVD in FA was significantly higher than PTC and MC, p < 0.001. Gal-8 may be used as a sensitive marker of PTC. The increased expression of Gal-8 in PTC than BTD and in lower TNM stage of carcinoma (I/II) is significant suggesting that Gal-8 may be used as one of diagnostic marker of PTC. Gal-8 also has a certain role in tumor angiogenesis.