Investigation of the Presence of Integrin Alpha-3 and Beta-1 Receptors on Tumor Tissue, Metastatic Lymph Node and Normal Tissue in Thyroid Cancer.

[OBJECTIVES] The important roles of integrins in tumor invasion, migration and proliferation are well known. In this study, we investigated the presence of integrin α3 and β1 receptors in tumor tissue, metastatic lymph node (LN) and normal thyroid tissue of patients diagnosed with thyroid cancer (TCa) and showed the prognostic and diagnostic value of these molecules as well as peptide-receptor.

[METHODS] Sixty-one patients with TCa were included in this study. The presence of integrin α3 and β1 expression was investigated by immunohistochemical methods from tumor tissue after total thyroidectomy. TNM system was used in tumor staging. The relationship between prognostic properties such as tumor size, LN metastasis, capsular invasion and the presence of integrin α3 and β1 expression was investigated.

[RESULTS] Classical type papillary TCa was the most common subtype in our study group with 31.1%. Integrin β1 was expressed in 4.9% (n=3) of normal tissue, 57.4% (n=35) of tumor tissue and 16.4% (n=10) of metastatic LN; integrin α3 was expressed in 50.8% (n=31) of normal tissue, 67.2% (n=41) of tumor tissue and 9.8% (n=6) metastatic LN. Integrin β1 expression was observed 21.3% (n=13), integrin α3 in 14.8% (n=9) and integrin α3 and β1 expression in 36.1% (n=22). Integrin β1 expression increased statistically significantly in the presence of LN metastasis and capsular invasion (p=0.022, 0.014, respectively). Furthermore, the expression of integrin α3 was found to be statistically significant in primary tumors of patients with LN metastasis (p=0.045).

[CONCLUSION] Our study showed a significant increase in integrin α3 and β1 expression in LN metastasis or thyroid capsule invasion in tumor. Thus, it appears that the demonstration of the presence of integrin α3 and β1 expression in TCa is not only a prognostic biomarker but also has value as a potential theranostic target with peptide-bound radioactive agents.