Runx2 mRNA expression in the tissue, serum, and circulating non-hematopoietic cells of patients with thyroid cancer.

ABSTRACT

CONTEXT Runx2, a master gene of osteogenic differentiation, is also expressed in nonosseous cancer cells. Microcalcifications are characteristic of papillary thyroid carcinoma and represent a useful find for diagnosis. However, the molecular expression of osteogenic differentiation transcription factor Runx2 has been poorly investigated in this tumor. OBJECTIVE: The aim of this study was to investigate Runx2 mRNA expression in normal and pathological thyroid tissue, serum, and circulating non-hematopoietic cells. SETTING: The study was performed in the Endocrine Unit of Internal Medicine of "Azienda Ospedaliera Universitaria Integrata of Verona" (Verona, Italy). PATIENTS We enrolled 12 patients with a papillary thyroid carcinoma (PTC), who had undergone total thyroidectomy performed by the same surgeon. The results, obtained by real-time RT-PCR, were compared with biological samples obtained from 13 sex- and age-matched normal donors. RESULTS: Our data demonstrated that Runx2 mRNA is overexpressed (7.81-fold expression) in pathological thyroid tissue than in normal tissue (P < 0.05). Runx2 mRNA overexpression was also observed in serum and circulating non-hematopoietic cells of PTC patients with respect to normal donors (5.91-fold expression, P < 0.001; 3.82-fold expression, P < 0.05, respectively). We also observed that patients with microcalcifications expressed significantly higher levels of Runx2 mRNA in serum with respect to patients without microcalcifications (P < 0.05). CONCLUSION: This study can open up new research perspectives in the diagnosis and follow-up of PTC, even if further and larger cohort studies will be necessary to validate the Runx2 expression as biomarkers in thyroid cancer.