Down-regulated  expression suppresses cell proliferation and promotes apoptosis in papillary thyroid carcinoma.

Papillary thyroid carcinoma (PTC) is the most common type of thyroid cancer. Hydroxysteroid dehydrogenase like 2 (HSDL2) can regulate lipid metabolism and take part in cell proliferation. The purpose of the present study was to explore functional role of HSDL2 gene in PTC. The expression of HSDL2 protein in PTC tissues was estimated using immunohistochemistry analysis (IHC). HSDL2 mRNA level was detected through quantitative real-time polymerase chain reaction (qRT-PCR). Effects of HSDL2 gene on cell proliferation and apoptosis were assessed using the shRNA method for both in vitro and in vivo experiments. Potential target genes of HSDL2 were determined via bioinformatics analyses and Western blotting. HSDL2 was up-regulated in PTC tissues and cell lines compared with the controls (all P<0.05). Inhibiting HSDL expression could suppress PTC cell proliferation and cycle, and promote apoptosis in vitro. In vivo, the knockdown of HSDL2 gene could significantly suppress tumor growth (all P<0.05). Furthermore, AKT3, NFATc2 and PPP3CA genes might be potential targets of HSDL2 in PTC. HSDL2 expression was increased in PTC tissues and cells, which could promote tumor progression in vitro and in vivo.