GW0742 as a Potential TRα and TRβ Antagonist Reduces the Viability and Metabolic Activity of an Adult Granulosa Tumour Cell Line and Simultaneously Upregulates TRβ Expression.

Background/objectives: Clinical studies have demonstrated a correlation between alterations in the expression level of TRα and TRβ receptors in ovarian cancer cells and overall survival. Celecoxib and GW0742, commonly known as a COX-2 inhibitor and a PPARβ/δ agonist, are novel thyroid hormone receptor antagonists that bind to TRβ or both TRα and TRβ.

Methods: The study was conducted on a non-luteinized ovarian granulosa cell line (HGrC1) and two rare ovarian cancer cell lines (COV434 and KGN). The expression of TRα and TRβ at the gene and protein levels was examined by real-time PCR and Western blot, respectively. The impact of GW0742 and celecoxib on the cell viability of the HGrC1, COV434 and KGN lines was evaluated using the PrestoBlue™ Cell Viability Reagent. The metabolic activity of the cells was analysed using the Seahorse XFp Analyzer.

Results: Initially, we observed that the gene and protein expression levels of TRα and TRβ were higher in COV434 and KGN cells than in HGrC1 cells. Subsequently, it was demonstrated that T₃ enhances the viability of HGrC1, COV434 and KGN cells. Furthermore, autoregulatory feedback loops were not observed during TRα or TRβ signalling in ovarian cancer cells, in contrast to the findings in healthy granulosa cells. Finally, we demonstrated that GW0742 reduced the viability and metabolic activity of granulosa cell tumours (GCTs). Simultaneously, we observed that GW0742 upregulated the expression of TRβ in GCT.

Conclusions: These findings suggest that GW0742 may be a novel adjuvant therapy for GCTs expressing TRα and TRβ.