Abstract 1502: Increased expression of KLK7 and KLK10 in papillary thyroid cancer

Abstract

Abstract The American Cancer Society estimates that there will be approximately 44,670 new cases of thyroid cancer and 1,690 deaths due to the disease in the United States in 2010. Approximately 80% of these cancers are papillary thyroid carcinoma (PTC), representing the most common endocrine malignancy. Kallikreins are serine proteases that have many physiological functions, including the remodeling of extracellular matrix (ECM). As PTC has the ability to degrade and remodel the ECM to facilitate penetration through the thyroid capsule and invasion of extra-thyroidal tissues, we investigated the expression of kallikrein 7 (KLK7) and kallikrein 10 (KLK10) in PTC. RNA expression of KLK7 and KLK10 in PTC was measured using real-time RT-PCR (normalized to GAPDH) (n = 26) and found to be significantly upregulated, with a mean fold change of 28.8 and 27.8 (P<0.05), in the tumor samples, relative to matched, normal tissue. Immunohistochemical analysis for KLK7 and KLK10 on patient samples (n = 16) revealed significantly increased immunohistochemical scoring/expression, with a mean increase of 3.0 and 2.7 (scale of 1-4; p< 0.001), respectively, in cancerous tissues, compared to adjacent, normal tissue on the same section. The data revealed a significant correlation between the expression of KLK7 and KLK10 on the both RNA level (Spearman r = 0.63, P<0.01), and on the protein level (Spearman r = 0.687, p<0.01). This coordinate expression suggests that the two kallikreins may share similar regulatory sequences. These data indicate that KLK7 and KLK10 may be useful biomarkers for the diagnosis of PTC in thyroid cancer. Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 102nd Annual Meeting of the American Association for Cancer Research; 2011 Apr 2-6; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2011;71(8 Suppl):Abstract nr 1502. doi:10.1158/1538-7445.AM2011-1502