FOXE1 polymorphisms: a new piece in the puzzle of thyroid dysgenesis

FOXE1 Gene is a Probable Tumor Suppressor Gene with Decreased Expression as Papillary Thyroid Cancers Grow, and is Absent in Anaplastic Thyroid Cancers

Papillary thyroid carcinoma (PTC), the most prevalent cancer of the thyroid, is more common in women than in men. To uncover the expression profile of FOXE1 gene in PTC tumor etiology. Microarray and RNA sequencing data on PTC in humans were analyzed. Eleven PTC tumor tissue samples and their neighboring normal tissue samples were collected. RT-qPCR was performed. Data normality, ROC construction, and logistic regression analysis were conducted. PTC tumors, normal tissues surrounding tumors, patients of different sexes and ages, metastasizing tumors, and tumor variants were assessed for FOXE1 expression. Eleven PTC tissues were obtained from seven women and four men. Among the PTC subtypes, there were two FV-PTCs, four C-PTCs, one microcarcinoma, and four tissues with an unknown subtype. FOXE1 gene expression was significantly increased in PTC tumors with dimensions less than 10 mm (relative expression = 14.437, p = 0.050). A significant increase in FOXE1 gene expression was observed in the normal tissue adjacent to the tumor, which was less than 10 mm in size, compared to the normal tissue adjacent to the tumor, which was larger than 10 mm (relative expression = 41.760, p = 0.0001). Females diagnosed with PTC showed a significant reduction in FOXE1 mRNA levels compared to their male counterparts (relative expression = 0.081, p = 0.042). In contrast to adjacent normal tissue, there was a significant reduction in FOXE1 gene expression in FV-PTC (relative expression = 0.044 and p = 0.0001). PTC tumors under 10mm had higher FOXE1 gene expression than larger tumors; normal tissue adjacent to smaller tumors also had higher FOXE1 expression. Females with PTC, regardless of their subtype, expressed less FOXE1 mRNA than males. FV-PTC tissues exhibited lower expression of FOXE1 mRNA than their adjacent normal tissues.

The molecular causes of thyroid dysgenesis: a systematic review

BACKGROUND

Congenital hypothyroidism (CH) is a frequent disease occurring with an incidence of about 1/2500 newborns/year. In 80-85% of the cases CH is caused by alterations in thyroid morphogenesis, generally indicated by the term "thyroid dysgenesis" (TD). TD is generally a sporadic disease, but in about 5% of the cases a genetic origin has been demonstrated. In these cases, mutations in genes playing a role during thyroid morphogenesis (NKX2-1, PAX8, FOXE1, NKX2-5, TSHR) have been reported.

AIM

This work reviews the main steps of thyroid morphogenesis and all the genetic alterations associated with TD and published in the literature.