LSD 1 modulates papillary thyroid carcinoma ( PTC ) cell proliferation through regulating TSHR

In this study, we explore the roles of LSD1 in papillary thyroid carcinoma cell proliferation and investigate the mechanisms. Total of 146 patients who have been diagnosed as PTC (papillary thyroid carcinoma) were enrolled in this study. Expressions of LSD1 in PTC cell lines (IHH-4 and B-CPAP) and tissues were analyzed by qRT-PCR and western blotting. Flow cytometry was used to explore the effects of LSD1 expression on PTC cell proliferation and cell cycle. Moreover, the effects of LSD1 expression on TSHR (thyroid-stimulating hormone receptor) expression was also analyzed using ChIP (chromatin immunoprecipitation) assay. Compared to the control groups, LSD1 was significant down-regulation in PTC tissues, as well as in PTC cell lines. Silenced LSD1 dramatically promoted IHH-4 and B-CPAP cells proliferation and released cell cycle at G0/G1 stage and critical increased cyclin D1 and TSHR expression. Furthermore, LSD1 suppressed TSHR transcription via modulating H3K4 demethylation. Our findings suggested that LSD1 modulates papillary thyroid carcinoma (PTC) cell proliferation through regulating TSHR, and provided a novel biomarker to predict the prognostic.