The Long Non-Coding RNA and Its Associated-Gene Are Down-Regulated in Human Thyroid Neoplasias and Act as Tumour Suppressors.

: Well-differentiated papillary thyroid carcinoma (PTC) represents the thyroid neoplasia with the highest incidence. Long non-coding RNAs (lncRNAs) have been found deregulated in several human carcinomas, and hence, proposed as potential diagnostic and prognostic markers. Therefore, the aim of our study was to investigate their role in thyroid carcinogenesis. : We analysed the lncRNA expression profile of 12 PTC and four normal thyroid tissues through a lncRNA microarray. : We identified 669 up- and 2470 down-regulated lncRNAs with a fold change >2. Among them, we focused on the down-regulated located in an antisense position with respect to the gene which codes for a metallophosphoesterase with tumour suppressor activity. Both these genes are down-regulated in benign and malignant thyroid neoplasias. The restoration of expression in thyroid carcinoma cell lines reduced cell proliferation and migration by modulating the PTEN/Akt pathway. Inhibition of thyroid carcinoma cell growth and cell migration ability was also achieved by the restoration. Interestingly, over-expression is able to increase expression. : Taken together, these results demonstrate that and might be considered as novel tumour suppressor genes whose loss of expression contributes to thyroid carcinogenesis.