Synergistic antitumor activity of sorafenib and MG149 in hepatocellular carcinoma cells

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.

Loss of hepatic Sirt7 accelerates diethylnitrosamine (DEN)-induced formation of hepatocellular carcinoma by impairing DNA damage repair

The mammalian sirtuin family (SIRT1-SIRT7) has shown diverse biological roles in the regulation and maintenance of genome stability under genotoxic stress. SIRT7, one of the least studied sirtuin, has been demonstrated to be a key factor for DNA damage response (DDR). However, conflicting results have proposed that Sirt7 is an oncogenic factor to promote transformation in cancer cells. To address this inconsistency, we investigated properties of SIRT7 in hepatocellular carcinoma (HCC) regulation under DNA damage and found that loss of hepatic Sirt7 accelerated HCC progression. Specifically, the number, size, and volume of hepatic tumor colonies in diethylnitrosamine (DEN) injected Sirt7-deficient liver were markedly enhanced. Further, levels of HCC progression markers and pro-inflammatory cytokines were significantly elevated in the absence of hepatic Sirt7, unlike those in the control. In chromatin, SIRT7 was stabilized and colocalized to damage site by inhibiting the induction of γH2AX under DNA damage. Together, our findings suggest that SIRT7 is a crucial factor for DNA damage repair and that hepatic loss-of-Sirt7 can promote genomic instability and accelerate HCC development, unlike early studies describing that Sirt7 is an oncogenic factor [BMB Reports 2024; 57(2): 98-103].