Additional file 1: Table S1. of The combination of four molecular markers improves thyroid cancer cytologic diagnosis and patient management

Set of primers used for genes analyses. (PDF 177 kb

Loss of c-KIT expression in thyroid cancer cells

<div><p>Papillary thyroid carcinoma is the most frequent histologic type of thyroid tumor. Few studies investigated the role of c-KIT expression in thyroid tumors, suggesting a role for this receptor and its ligand in differentiation and growth control of thyroid epithelium and a receptor loss following malignant transformation. We investigated and correlated c-KIT expression levels and two known markers of thyrocytes differentiation, PAX8 and TTF-1, in malignant and benign cytological thyroid samples. Moreover, we performed functional studies on human papillary thyroid carcinoma cell line to associated c-KIT expression to thyrocytes differentiation and tumor proliferation. c-KIT and PAX8 expression resulted higher in benign samples compared to the malignant ones, and the expression levels of these two genes were significantly correlated to each other. We also observed that c-KIT overexpression led to an increase of PAX8 expression level together with a decrease of proliferation. Furthermore, c-KIT overexpressing cells showed a regression of typical morphological features of malignancy. Taken together these results suggest that c-KIT could be involved in the differentiation of thyroid cells and in tumor progression.</p></div

Effect of c-KIT overexpression on cell proliferation.

<p>WST-1 based proliferation assays were performed for control, empty vector transfected cells and c-KIT overexpressing cells.</p

Effect of c-KIT overexpression on cell morphological characteristics.

<p>Four principal malignancy features were more represented in empty vector transfected cells (A) than c-KIT overexpressing cells (B): high nuclear-cytoplasmic ratio (black thick arrows); presence of powdery chromatin pattern, sometimes with clumps (black thin arrows) presence of macro and multiple nucleoli (white thick arrows) cells presenting more nuclei (2 or 3).</p

PAX8 overexpression in benign thyroid nodules.

<p>PAX8 mRNA expression in PTC (n = 39) and BN (n = 30) (FNAC) samples.</p

c-KIT overexpression in c-KIT+ transfected cells.

<p>c-KIT mRNA expression in control, empty vector transfected cells and c-KIT overexpressing cells.</p

TTF-1 downregulation in benign thyroid nodules.

<p>TTF-1 mRNA expression in PTC (n = 39) and BN (n = 30) (FNAC) samples.</p

PAX8 overexpression in c-KIT+ transfected cells.

<p>PAX8 mRNA expression in empty vector transfected cells and c-KIT overexpressing cells.</p

Presence of atypical cells in c-KIT- and c-KIT+ cells.

<p>Abnormal cells (A) in empty vector transfected cells and c-KIT overexpressing cells (B).</p

Regression analysis between and gene expression in 69 thyroid nodules including 30 BN and 39 PTC.

<p>Data are expressed in relative normalized expression levels after normalization by B₂M gene expression. High c-KIT mRNA levels were associated with a clear increase of PAX8 mRNA level.</p