To investigate the relationship between the expression of SK4 and clinicopathological characteristics, and evaluate the influence of SK4 on central 1ymph node metastasis of papillary thyroid carcinoma.

Tissue microarray and immunohistochemistry were used to detect the SK4 expression in 88 cases of papillary thyroid carcinoma tissues. According to the SK4 immunohistochemical staining results, we divided into SK4 positive expression group (55 cases) and SK4 negative expression group (33 cases). The papillary thyroid carcinoma cells served as the control group, and those with SK4 knockdown by cellular experimental small interfering RNA (siRNA) served as the experimental group. Chi-square test was used to assess the relationship between SK4 expression and clinicopathological characteristics. The logistic regression model was used to investigate the risk factors for central lymph node metastasis of papillary thyroid carcinoma. All data were analyzed by SPSS statistics version 22.0 and Graphpad prism 5.0 software.

In 88 cases of papillary thyroid carcinoma tissues, 55 cases were positive for SK4 (62.5%). The positive expression rate of SK4 in lymph node metastasis in the central region of papillary thyroid carcinoma was 73.3% (33/45), and the positive expression rate of SK4 was 66.7% (24/33) in stage Ⅰ, 23.1% (3/13) in stage Ⅱ, 80.6% (25/33) in stage Ⅲ, and 50.0% (3/6) in stage Ⅳ. Chi-square test showed that SK4 expression was significantly associated with central lymph node metastasis (χ²=4.611, P<0.05) and clinical stage (χ²=11.762, P<0.05), and SK4 expression was not significantly correlated with age (χ²=0.724, P>0.05), gender (χ²=1.343, P>0.05), T-stage (χ²=2.799, P>0.05), and tumor site (χ²=0.637, P>0.05). Logistic regression analysis showed SK4 and clinical stage were independent risk factors for central lymph node metastasis of papillary thyroid carcinoma (OR=3.827, 3.882, P<0.05). After SK4 knockout, the invasion and migration ability of papillary thyroid cancer cells was obviously inhibited. The invasion and migration capacity in the SK4 knockout group was significantly lower than in the control group (224 cells vs. 690 cells; 196 cells vs. 571 cells;t=185.900, 138.600, P<0.01).

SK4 expression is strongly linked to central lymph node metastasis of papillary thyroid cardnoma.

Thyroid carcinoma; Lymph node metastasis; Tissue microarray