Investigation On Peripheral Blood Thyroid Tissue-specific MRNA For Differentiation Of Benign And Malignant Thyroid Nodules

Objective:The aim of this study was to evaluate the diagnostic value of thyroid tissue-specific mRNA, including thyroglobulin (Tg) mRNA, thyroid stimulating hormone receptor (TSHR) mRNA and thyroid peroxidase (TPO) mRNA, in peripheral blood samples of patients with differentiated thyroid carcinoma(DTC). Additionally, to analyze the relationship between Tg mRNA, TSHR mRNA and TPO mRNA and clinical and pathological features, and provide the evidence for early diagnosis of thyroid carcinoma.Methods:Postoperative histopathology as the gold standard were carried out, the peripheral blood cell samples coming from tested people divided into three groups, including benign thyroid nodules, thyroid malignant nodules and normal control group. After venous blood samples were collected, we extracted total RNA from the peripheral blood mononuclear cells, immediately. And, we use real-time quantitative RT-PCR technique to test the relative expression of Tg mRNA, TSHR mRNA and TPO mRNA for nucleated cells in peripheral blood.Results:(1)In 126 cases of patients with thyroid nodules, We found that the expression of Tg mRNA, TSHR mRNA and TPO mRNA in the group of malignant thyroid nodules were higher than those in the group of benign nodules(p<0.01); The expression of TSHR mRNA and TPO mRNA in the group of benign nodules were higher than those in normal controls(p<0.01); The expression of Tg mRNA was no significant difference between benign nodules and normal control group. (2)In the group of malignant thyroid nodules, the expression of Tg mRNA was higher when found enveloping violations and lymph node metastasis, compared with the group without it(p<0.05); The expression of TSHR mRNA and TPO mRNA showed no significant relationship with enveloping violations and Lymph node metastasis(p> 0.05). (3)TgAb (+) group with thyriod malignant nodules, the relative expression of Tg mRNA was significantly higher than those in TgAb (-) group, and there was a positive correlation between Tg mRNA and TgAb (p<0.05). (4)In the group of malignant thyroid nodules, the expression of Tg mRNA, TSHR mRNA and TPO mRNA showed no significant relationship with sex, age, size and number of nodules in these patients(p>0.05).Conclusion:(1)Real-time quantitative RT-PCR technique have been utilized to detect the relative expression of peripheral blood Tg mRNA, TSHR mRNA and TPO mRNA in 126 cases of patient with thyroid nodules and 30 cases of healthy individuals, Tg mRNA, TSHR mRNA and TPO mRNA expressed in normal peripheral blood cells at low level.(2)The expression of Tg mRNA, TSHR mRNA and TPO mRNA in the group of malignant nodules was significantly higher than those in benign nodules and normal control group, that can be taken as a reliable indicator of early diagnosis of thyroid nodules.(3)In the group of malignant thyroid nodules, the expression of Tg mRNA was higher when found enveloping violations and lymph node metastasis, suggest that it may be associated with thyroid carcinoma invasiveness. (4)In the group of malignant thyroid nodules, the expression of Tg mRNA in TgAb (+) group was higher than that in TgAb(-) group, and there is a positive correlation between Tg mRNA and TgAb, indicate that TgAb may be taken as a secondary indicator to diagnose early thyroid carcinoma. (5)In the group of malignant thyroid nodules, the expression of Tg mRNA, TSHR mRNA and TPO mRNA showed no significant relationship with sex, age, size and number of nodules.