MG149 suppresses anaplastic thyroid cancer progression by inhibition of lysine acetyltransferase KAT5-mediated c-Myc acetylation.

Background: Anaplastic thyroid cancer (ATC) is a highly lethal form of thyroid cancer. lysine acetyltransferase 5 (KAT5) has been found to promote ATC development via c-Myc stabilization by previous study. We thus designed experiments to confirm the anti-tumor effect of a KAT5 inhibitor (MG149) in ATC.

Methods: Western blotting assessed the level of KAT5, c-Myc, and epithelial-mesenchymal transition (EMT)-related proteins in ATC cells and xenograft tumor tissues. Cell counting kit-8, flow cytometry, wound healing, and transwell assays revealed the effect of MG149 on cell proliferation, apoptosis, migration, and invasion in ATC cell lines. Immunofluorescence detected the level of E-cadherin and N-cadherin in ATC cell lines. The effect of MG149 on KAT5-mediated c-Myc stabilization was detected using co-immunoprecipitation assay. Tumor volume and tumor weight in ATC xenograft models were evaluated. H&E staining showed the effect of MG149 on lung metastasis in vivo. We further investigated whether MG149 can enhance the sensitivity of ATC to cisplatin (CDDP).

Results: MG149 inhibited cell proliferation and increased the apoptosis of cells. MG149 suppressed the migratory and invasive ability of ATC cells. The EMT in CAL-62 and 8505C cells was significantly inhibited by MG149. MG149 suppressed the KAT5-mediated c-Myc acetylation. MG149 inhibited tumor growth and lung metastasis in vivo. Additionally, MG149 potentiated the sensitivity to CDDP in ATC cells in vitro and in vivo.

Conclusion: MG149 suppresses ATC progression and metastasis by inhibiting the acetylation of c-Myc mediated by KAT5.