title: Downregulation of LSD1 suppresses the proliferation, tumorigenicity and invasion of papillary thyroid carcinoma K1 cells.
abstract: The present study aimed to evaluate the effects of lysine-specific demethylase 1 (LSD1) downregulation, induced by small interfering RNA (siRNA) transfection, on the proliferation, colony formation, migration and invasion of the papillary thyroid carcinoma K1 cell line. The siRNA targeting LSD1 and scrambled non-targeting siRNA were each transfected into papillary thyroid carcinoma K1 cells. Downregulation of LSD1 mRNA and protein level was evaluated by reverse transcription-quantitative polymerase chain reaction, and immunocytochemical (ICC) analysis and western blotting, respectively. A Cell Counting kit-8 assay was applied to estimate the effect of LSD1-siRNA on cell growth. Migration and invasion abilities were estimated by Transwell chamber assay. A soft agar colony formation assay was performed to estimate the effect of LSD1-siRNA on tumorigenicityin vitro. ICC data showed that LSD1 protein was strongly expressed in the blank and control K1 cells compared with the LSD1-siRNA cells (F=15.192, P<0.01). Compared with the control cells, cells transfected with siRNA targeting LSD1 exhibited significant downregulation of LSD1 mRNA (t=6.845, P<0.01) and protein (F=53.764, P<0.01) levels. siRNA targeting LSD1 also downregulated cell proliferation following transfection for 24, 48 and 72 h (t=4.777, P<0.001; t=3.302, P=0.003; and t=3.017, P=0.006, respectively). Compared with the control group, the amount of cell invasion was gradually reduced in the LSD1-siRNA group (t=12.301, P<0.01). The number of migrating cells was significantly higher in the negative control group compared with the LSD1-siRNA group (t=7.911, P<0.01), and the ability of colony formation in the LSD1-siRNA cells was notably reduced in the soft agar formation assay (t=3.612, P=0.005). siRNA targeting LSD1 efficiently inhibits the proliferation, colony formation, migration and invasion of papillary thyroid carcinoma K1 cells.
authors.affiliation: Department of Pathology, Basic Science School, Jining Medical University, Jining, Shandong 272067, P.R. China.
authors.forename: Ling-Ling
authors.initials: LL
authors.lastname: Kong
authors.affiliation: Department of Gynecology, Affiliated Hospital of Jining Medical University, Jining, Shandong 272029, P.R. China.
authors.forename: Dong-Mei
authors.initials: DM
authors.lastname: Man
authors.affiliation: Department of Electrocardiography, The First Affiliated Hospital of Jining Medical University, Jining, Shandong 272111, P.R. China.
authors.forename: Tian
authors.initials: T
authors.lastname: Wang
authors.affiliation: Department of Pathology, Basic Science School, Jining Medical University, Jining, Shandong 272067, P.R. China.
authors.forename: Guo-An
authors.initials: GA
authors.lastname: Zhang
authors.affiliation: Department of Pathology, Basic Science School, Jining Medical University, Jining, Shandong 272067, P.R. China.
authors.forename: Wen
authors.initials: W
authors.lastname: Cui
keywords: Transwell chamber assay; lysine-specific demethylase 1; papillary thyroid carcinoma; small interfering RNA; soft agar colony formation assay