Evaluation of NDRG2 gene expression in primary papillary thyroid carcinoma and in metastases of this neoplasm to regional lymph nodes

BACKGROUND: At present, researchers' attention has been concentrating on NDRG2 (N-Myc downstream-regulated gene 2) as a new gene candidate in the development and progression of papillary thyroid carcinoma (PTC). NDRG2, together with NDRG1, NDRG3 and NDRG4 are members of the NDRG family, a new class of genes, inhibited by N-Myc oncogene. AIM: The aim of our study was to evaluate NDRG2 mRNA expression in the primary PTC and its metastases to regional lymph nodes. MATERIALS AND METHODS: Postoperative tissue and macroscopically changed lymph nodes of sixteen (16) patients with PTC constituted the studied material. In this group, metastases of the cancer to regional lymph nodes were confirmed histopathologically in 8 cases. Quantitative evaluation of NDRG2 mRNA expression was performed by the real-time polymerase chain reaction (real-time PCR) method. RESULTS: The mean values of NDRG2 mRNA expression in the primary tumour tissues were statistically significantly lower vs. the levels of NDRG2 mRNA expression in macroscopically unchanged thyroid tissue (p < 0.0001). A comparison of the mean NDRG2 mRNA expression of primary tumours and that of their metastases to regional lymph nodes did not demonstrate any statistical differences (p > 0.05). A positive correlation was observed between NDRG2 mRNA expression in primary tumour cells and in the cancer metastases to lymph nodes (Rs = 0.7857; p < 0.05). Factors, such as age, sex, tumour stage in TNM system, were of no significance for NDRG2 mRNA expression level (p > 0.1). CONCLUSION: The results of our study demonstrated decreased NDRG2 mRNA expression levels in PTC, when compared to macroscopically unchanged thyroid tissue, which may point to the potential role of NDRG2 in the development and progression of cancer in question.