Expression of Matrix Metalloproteinase 7 and Fibronectin in Papillary Thyroid Cancer: Gene Expression Profiling using real time PCR

Papillary thyroid cancer (PTC) is usually indolent with a high frequency of lymph node metastasis. Rarely, PTC behaves in a more aggressive fashion; however, the mechanisms of invasion and metastasis in thyroid cancer remain poorly understood. We studied 4 cases of PTC in which fresh frozen tissue were available. Two had a distant metastasis to the lung and bone and the other two had only local disease. Benign thyroid with nodular hyperplasia was used as a normal control. Frozen sections were prepared and the tumor and normal tissues were microdissected. We used the Human Tumor Metastasis RT2 profiler PCR Array (SA Bioscience, Frederick, MD) and a high performance SYBR green real‐time PCR (LightCycler, Roche, Indianapolis, IN). The array represents 84 genes known to be involved in metastasis. After processing, statistical analysis was performed using the PCR Array Data Analysis Web Portal.The analysis of 2 PTCs without hematogenous metastasis showed down‐regulation of matrix metalloproteinases (MMPs) and fibronectin (FN). Significant over‐expression of MMPs, especially MMP7, and FN were found in 2 PTC with hematogenous metastasis .Compared to normal control and PTC without hematogenous metastasis, ratios of FN and MMP7 expression were 612.6 and 833.62, respectively. Our findings of significant up‐regulation of MMP7 and FN may identify patients who have PTC with more aggressive behavior