Quantitative analysis of thyroid adenoma associated (THADA) and high-mobility group AT-hook 2 (HMGA2) in dedifferentiated and extra-embryonic human tissues

Abstract

Analysis of the genomic structure of THADA revealed a size of 365 kbp and 38 exons in the full-length form. In case of a truncation often found in thyroid adenomas, the breakpoints are located in intron 28, thereby translocating the 3'-end of the gene. Own research elucidated that its protein is located in the cytoplasm, independent of the existence of the carboxy terminus. THADA turned out to be a marker of dedifferentiation of thyroid tissue. In the thyroid THADA might have a particular role, since its expression turned out to be significantly higher in this organ than in several other tissues. Also, only in the thyroid a negative correlation with HMGA2 could be detected. HMGA2 is a marker for the dedifferentiation of thyroid tissue, thereby verifying the results obtained in the analysis of THADA expression. HMGA2 is known to play an important role in early development. This could be confirmed for fetal placenta samples. High qRT-PCR values were detected in samples from the first trimester, whereas a baseline expression could be observed up until birth. While HMGA2 is mostly downregulated in adult tissues, reexpression can be found in several tumors, especially in malignant neoplasias. This is also the case for testicular germ cell tumors. A subgroup-specific expression could be distinctively determined. It could also be shown, that use of qRT-PCR and immunohistochemistry on HMGA2 might serve as a marker in clinical application.