BACKGROUND: The WD repeat domain 5 (WDR5) is an essential component of methyltransferase complexes. The expression of WDR5 has been reported in several types of malignancy. This study aimed to investigate the expression of the WDR5 gene and protein in a human papillary carcinoma cell line in vitro, including the use WDR5 gene silencing, and the expression of the WDR5 protein in papillary thyroid carcinoma tissue, and clinicopathological characteristics including overall survival (OS).

MATERIAL AND METHODS: The role of WDR5 in proliferation and migration of the human papillary thyroid carcinoma cell line, KTC-1, was investigated using the cell counting kit-8 (CCK-8) assay and transwell assay after silencing WDR5 expression. Expression levels of WDR5 in 84 patients with papillary thyroid carcinoma were detected using immunohistochemistry. The correlation between WDR5 expression and clinicopathological features was analyzed using the chi-squared test. The prognostic role of WDR5 was evaluated by univariate analysis with the log-rank test, and by multivariate analysis with the Cox regression model.

RESULTS: WDR5 expression promoted the proliferation and migration of the KTC-1 cells. In tumor tissue from patients with papillary thyroid carcinoma, low expression and high expression levels of WDR5 were found in 72.6% and 27.4%, respectively. Increased expression of WDR5 was significantly associated with lymphatic invasion and reduced survival rates. WDR5 expression was an independent negative prognostic biomarker.

CONCLUSIONS: Expression of WDR5 promoted cell proliferation and migration in vitro and was associated with reduced prognosis in patients with papillary thyroid carcinoma.

Keywords: Biological Markers, Asians, Biomarkers, Tumor, Carcinoma, Papillary, Histone-Lysine N-Methyltransferase, Thyroid Cancer, Papillary