Pituitary NR4A1 is negatively regulated by thyroid hormone without direct binding of thyroid hormone receptors on the gene

NR4A1 promotes LEF1 expression in the pathogenesis of papillary thyroid cancer

The morbidity of papillary thyroid cancer (PTC) is on the rise, but its pathogenesis is still poorly understood. NR4A1 is a transcription factor primarily involving a wide range of pathophysiological responses, but its relationship with PTC malignancy remains unclear. This study demonstrates that high NR4A1 expression is strongly associated with poor survival outcomes in PTC patients. The depletion of NR4A1 significantly inhibited the proliferation of PTC cells by negating the LEF1-mediated oncogenic alteration. Mechanistically, NR4A1 directly binds to the promoter region of LEF1 and leads to crosstalk with histone acetylation and DNA demethylation to transcriptionally upregulate LEF1 expression, subsequently promoting downstream growth-related genes expressions in PTC. In the light of our findings, NR4A1 may be an emerging driving factor in PTC pathogenesis and progression.

Regulation of the KCNJ5 gene by SF-1 in the adrenal cortex: Complete genomic organization and promoter function

Activating mutations in the KCNJ5 gene are responsible for the significant number of aldosterone-producing adenomas. To elucidate the molecular mechanisms underlying KCNJ5 expression, we characterized the entire human KCNJ5 gene. The gene spanned approximately 29.8 kb and contained three exons and two introns. The strongest expression of KCNJ5 mRNA was observed in the adrenal gland. The promoter region contained a putative binding site for SF-1 at -1782 bp. A construct containing -2444 bp of the promoter region exhibited the strongest promoter activity in adrenal H295R cells, and the introduction of a mutation in the SF-1 binding site almost completely abolished promoter activity. Furthermore, deletion mutation, EMSA, and knockdown analyses revealed that SF-1 bound to this element and was functional. Immunochemistry showed that KCNJ5 was predominantly expressed in the zona glomerulosa, while SF-1 was ubiquitously expressed in the adrenal cortex. These results demonstrated that SF-1 mediates the expression of human KCNJ5 in the adrenal cortex.