Background: Signal transducer and activator of transcription-1 (STAT1) plays a critical role in tumorigenesis by controlling several functions in both tumor cells and the immune system, and is considered to be a tumor suppressor. The present study evaluated the activity of STAT1 in human papillary thyroid carcinomas (PTC).
Methods: STAT1 activity was measured in nuclear extracts of tumor tissues from 35 PTC patients using an ELISA-based kit.
Results: STAT1 activity was significantly lower in tumors than in the surrounding normal thyroid tissues (P < 0.01). The association between STAT1 activity and clinicopathologic factors was analyzed in PTC tissues. STAT1 activity was significantly lower in tumors that measured 2 cm or more than in tumors that measured 2 cm or less (P = 0.044). Moreover, tumor size was inversely correlated with STAT1 activity (Spearman's rank correlation coefficient (rho) = -0.34, P = 0.048). In addition, tumors with BRAF mutations showed lower STAT1 activity than wild-type BRAF tumors [0.064 (0.056-0.124) vs. 0.108 (0.073-0.153) arbitrary units, P = 0.048].
Conclusion: STAT1 activity is suppressed in PTCs (as measured by DNA-binding activities). The tumor with T1799A BRAF mutation and tumor sizes of 2 cm or more were clinicopathologic parameters associated with lower STAT1 activity. STAT1 activity of tumor might be one of potential biomarkers for PTC's.
Copyright © 2012 Wiley Periodicals, Inc.