RET/PTC1 Rearrangement in Hashimoto's Thyroiditis: Canonical WNT Expression Upregulation for Neoplastic Promotion
More than half a century has passed since the association between papillary thyroid carcinoma (PTC), and Hashimoto's thyroiditis (HT) has been posted. The discovery of the RET/PTC oncogene thirty years later has further strengthened this argument, followed by the associations made between hyalinizing trabecular adenoma (HTA) and both PTC and HT. Numerous researchers studied these relationships, with some debating a valid link. Findings: This case of a 28-year-old woman with HT- associated PTC
... T- associated PTC and a co-existing HTA, offers a unique opportunity to study these three diseases together in the same microenvironment. Fresh tissue analysis for gene expression showed that all three expresses RET/ PTC1 transcripts, while this was not seen in the control normal thyroid tissue. There was also an increased expression of AKT, ERK1, nuclear β-catenin and TCF4 in both the HTA and PTC sampled tissue. AKT plays a central role in regulating cell proliferation and survival by inhibiting apoptotic processes, while ERK1 leads to cell proliferation. Both β-catenin and TCF4 are linked to the canonical WNT/β-catenin pathway. Conclusion: The expression of RET/PTC1 highlights the link between inflammatory processes such as HT and neoplastic diseases such as HTA and PTC. The limited expression of TCF4, AKT, ERK1, and β-catenin supports the notion that the canonical WNT/β- catenin pathway plays a pivotal role in the development of this neoplasm subtype. To date, gene expression alone is not sufficient to make a distinction between benign and malignant thyroid tumors.