Enhanced annexin A2 expression with poor clinical parameters in papillary thyroid carcinoma

Abstract Objectives Annexin A2 (Anxa2) has been implicated in regulating tumor progression. However, the role in driving thyroid cancer development is unclear. Herein, this study aimed to investigate the possible role of Anxa2 in the pathogenesis of thyroid cancer. Methods The expression of Anxa2 in thyroid cancer was retrieved from bioinformatics data from the Gene Expression Omnibus (GEO) and The Cancer Genome Atlas (TCGA). Additionally, 16 paired papillary thyroid carcinoma (PTC) tissue samples and another three unpaired PTC tissues were collected from Taipei Medical University (TMU), and commercially available complementary (c)DNA and tissue arrays of thyroid cancer were also obtained. Results Anxa2 mRNA expression was increased in PTC in datasets of the GEO database. Additionally, the Anxa2 transcript was increased in PTC, and its expression related to the BRAF mutation, a young age onset, tumor size, lymph node invasion, and advanced disease in the TCGA database. Moreover, the increase in Anxa2 messenger (m)RNA in PTC was also validated from both a TMU cohort (PTC=19, normal=16, p<0.001) and a commercial cDNA array (PTC=32, normal=5; p<0.001). In the cDNA array analysis, Anxa2 mRNA levels were associated with tumor expansion (p=0.013) and advanced staging (p=0.044). However, despite the Anxa2 protein being increased in PTC (PTC=36, normal=8; p<0.001), no significant associations with tumor staging or extent (p=0.053) were observed. Conclusions Anxa2 transcript and protein expressions were upregulated in PTC. Its expression levels were associated with unfavorable clinical parameters. Further, well-designed studies are needed to clarify the underlying mechanisms of Anxa2 in thyroid tumorigenesis.