Expression of HLA-G in the peripheral blood and cancerous tissues of patients with papillary thyroid cancer / 中华内分泌外科杂志

ABSTRACT

Objective:To examine the expression of human leukocyte antigen G (HLA-G) in the peripheral blood and cancerous tissues of patients with papillary thyroid carcinoma (PTC) .Methods:The expression of soluble HLA-G (sHLA-G) in the peripheral blood of 50 individuals with PTC (PTC group) , 25 patients with benign thyroid tumors (BTT group) from Department of Thyroid and Breast Surgery, Beilun branch of the First Affiliated Hospital of Zhejiang University and 20 healthy controls (healthy control group) from physical examination center was assessed by ELISA. Immunohistochemical examination of HLA-G levels was also performed on tissue specimens from patients in the PTC and BTT groups, and their correlation with clinicopathological features of thyroid cancer was analyzed. SPSS 19.0 was used for statistical analysis. The measurement data of normal distribution were tested by two independent samples t test. Chi square test was used to compare the rates between the two groups. Results:The sHLA-G expression in peripheral blood was 21.33 (±5.54) , 22.73 (±4.99) , and 18.29 (±4.43) ng/mL in the preoperative PTC, BTT, and healthy control groups, respectively. Compared to the healthy group, sHLA-G levels were considerably higher in the PTC and BTT groups, with statistically significant differences (totally P < 0.05) . There was no significant difference in statistically sHLA-G levels between the BTT and PTC groups ( P > 0.05) . The positive HLA-G expression rate in PTC tissues was 78% (39/50) . There was no evidence of HLA-G expression in common tissues adjacent to PTC. HLA-G was not expressed in benign tumors. HLA-G was linked with the PTC tumor diameter, and the rate of positive expression was considerably greater with tumor diameters >1 cm than with those ≤1 cm ( P<0.05) . The rate of HLA-G positive expression was not significantly correlated with sex, age, multiple foci, extra-glandular invasion, metastasis of lymph nodes, or the TNM stage in PTC individuals ( P > 0.05) . Conclusions:HLA-G is significantly expressed at high levels in PTC tissues, is correlated with the tumor diameter, and may probably have a significant role in this disease. Peripheral blood sHLA-G may be associated with thyroid tumorigenesis, and its value in PTC requires further verification.