The Expression Of Osteopontin In Peripheral Blood And Tissues In Papillary Thyroid Carcinoma

OBJECTIVE:To investigate the expression of osteopontin (OPN) in the peripheral blood and tissues of papillary thyroid carcinoma, benign thyroid nodule and normal human control. To analyze the relationship of the OPN expression between peripheral blood and thyroid tissues. To explore the possibilities of OPN as a tumor marker of papillary thyroid carcinoma.METHODS:75 patients with thyroid nodules who had thyroidectomy from August 2010 to January 2011 in Qilu Hospital of Shandong University were collected. It included 14 males and 61 females. All subjects was divided into two groups according to the result of histopathologic diagnosis:The papillary thyroid carcinoma group, which included 38 cases,6 males and 32 females, and the benign thyroid nodule group, which included 37 cases,8 males and 29 females. The clinical data of all patients were collected, such as gender, age, the size of the thyroid nodules, description of thyroid ultrasound, level of thyroid stimulating hormone before operation, family history, past thyroid disease history, operation history, pathological result and description of lymph node metastasis in papillary thyroid carcinoma.The preoperative OPN level in peripheral blood and the expression of OPN in tissues were tested respectively.The expression of OPN was detected by immunohistochemical SP staining in tissues of 22 papillary thyroid carcinoma, comparing with the expression of that in tissues of 18 benign thyroid nodule. Enzyme-linked immunoabsorbent assay (ELISA) was applied to detect the concentration of OPN in the peripheral blood of 38 patients with papillary thyroid carcinoma,37 patients with benign thyroid nodule and 30 health subjects.RESULTS:1. OPN was mainly distributed in the cytoplasm. The positive rate of OPN was 86.36% in papillary thyroid carcinoma group, while 44.44% in benign thyroid nodule group. The level of OPN was significantly higher in the tissues of patients with papillary thyroid carcinoma than in the tissues of patients with benign thyroid nodule. There was statistically significant difference between the two groups.2. Serum OPN level was 31.57±4.36μg/L,31.22±5.37μg/L,30.75±6.49μg/L in papillary thyroid carcinoma group, benign thyroid nodule group and normal human control group respectively. There was no statistically significant difference among the three groups.3. The papillary thyroid carcinoma group was classified according to whether lymph node metastasis was present. The level of OPN in the two groups was compared. The serum OPN level of lymph metastasis group and non lymph metastasis group was 30.88±4.76μg/L,31.76±4.31μg/L respectively. There was no statistically significant difference between the two groups.4. The correlation of OPN expression between thyroid tissues and serum was not found.CONCLUSIONS:1. Higher OPN expression level in thyroid tissues was observed in the patients with papillary thyroid carcinoma. The level of OPN was significantly higher in the tissues of patients with papillary thyroid carcinoma than in the tissues of patients with benign thyroid nodule. There was statistically significant difference between them. It appeared that the expression of OPN in thyroid tissues is clinically useful in the differential diagnosis of benign and malignant thyroid nodule.OPN may be a potent tumor marker for diagnosis of papillary thyroid carcinoma.2. The level of OPN in the peripheral blood meant little to the differential diagnosis of benign and malignant thyroid nodule. 3. The lymph node metastasis in papillary thyroid carcinoma can't be prognosticated by the preoperative serum OPN level.4. The correlation of OPN expression between thyroid tissues and serum was not found.