Diagnosis Of Benign And Malignant Follicular Thyroid Tumor By Using Four Molecular Biomarkers

Objective:It is quite difficult in the differentiation of follicular thyroid carcinoma (FTC) and benign follicular adenomas. Some reports on molecular markers to distinguish thyroid follicular carcinomas from adenomas have been published. A new approach to differentiate malignant and benign thyroid nodules might become reality according to detection the expression of molecular biomarkers. However, none of the molecules individually is sufficiently sensitive and specific to be able to act as an independent diagnostic biomarker. Recently, some researchs reported that DNA damage inducible transcript3(DDIT3), chromosome1open reading frame24(C1orf24), highmobility group A2(HMGA2) and intestinal trefoil factor (TFF3) might have somewhat sensitivity and specificity to distinguish thyroid follicular carcinomas from adenomas. The goal of this study was to determine if TFF3, DDIT3, C1orf24, HMGA2could be used alonely or combinedly to distinguish between benign and malignant thyroid lesions. Moreover, gene expression was detected by real-time quantitative PCR.Methods:Twenty-nine tissue samples were collected from patients undergoing thyroid surgery for thyroid nodules between January2011and October2011in Nanjing general hospital of Nanjing military region, including8papillary thyroid carcinoma (PTC),12follicular thyroid adenoma (FTA),8follicular thyroid carcinoma (FTC)(including1follicular variant of papillary thyroid carcinoma). Six normal thyroid specimens were served as the control group. Final histologic diagnosis was obtained from paraffin-embedded tissue. These samples were frozen immediately after surgery and stored at-80℃. Total RNA was extracted from tissues according to the manufacturer's protocol, after reverse transcription, the expression levels of genes of TFF3, HMGA2, Clorf24and DDIT3, and reference gene Beta-actin were analyzed by real-time fluorescence quantitative-polymerase chain reaction (RT-PCR). We used the relative-expression data(2-△CT) obtained from RT-PCR analysis. Data were shown as mean±SD. Statistical analyses were performed by Student's t-test. Significance was accepted at P values of <0.05. All data were analyzed by software SPSS16.0.Results:①In comparison with normal thyroid tissue, the expression of c1orf24mRNA in the FTA group decreased significantly (P<0.05). Compared with normal group and FTA group, clorf24mRNA level was overexpression in FTC group, and the difference significant between FTA and FTC groups(P<0.05).②The expression of DDIT3mRNA was significantly different between the normal and FTA tissue groups (P<0.05); Moreover, DDIT3mRNA expression level in FTC was higher than FTA (P<0.05).③The RT-PCR analysis showed a significant increase in HMGA2mRNA level of follicular carcinomas was found in comparison with normal thyroid tissue and follicular adenomas, and there was a significant difference between FTA and FTC groups(P<0.05), and the significant differences between FTA group and normal tissue group were also found (P<0.05).④There were decreases in TFF3mRNA level of follicular carcinomas and follicular adenomas in comparing with normal tissues, and the expression level of TFF3mRNA was higher in FTC group compared to FTA group (P<0.05)Conclusion:The RT-PCR analysis showed that the expression levels of the four genes including TFF3, HMGA2, C1orf24, and DDIT3were significant difference between FTC and FTA groups. This may be useful for the differentiation between follicular adenomas and carcinomas.