OPN -443C>T genetic polymorphism and tumor OPN expression are associated with the risk and clinical features of papillary thyroid cancer in a Chinese cohort.

Aim: to test the possible association between the polymorphism of Osteopontin (OPN) gene with the risk and the clinical features of papillary thyroid cancer (PTC).

Methods: A total of 363 PTC patients and 413 healthy controls were enrolled. OPN expressions in tumor tissue were detected by immunohistochemistry. OPN gene polymorphisms, namely, -66T>G (rs28357094), -156G>GG (rs17524488), and -443C>T (rs11730582), were determined.

Results: We observed that the PTC patients had significantly higher rates of -443TT genotypes than controls (P<0.001). The multivariate logistic regression analysis showed a significantly increased risk for PTC for the -443CC genotype compared with the -443TT genotype (adjusted OR= 4.312, 95%CI: 2.747 -6.987, adjusted P < 0.001). OPN protein was not expressed in normal thyroid tissues while tumor samples from PTC patients were shown to have high expressions of OPN. Also, we found that the high OPN expressions were significantly more prevalent in -443CC carriers than TT carriers (P <0.001). Both the CC carriers and OPN expression were closely associated with the cervical lymph node metastasis and angiolymphatic invasion of PTC.

Conclusion: This study provides evidence to support the connection between the OPN genetic polymorphism and tissue expression with risk as well as the invasiveness of PTC.