Combined inhibition of AURKA and HSF1 suppresses proliferation and promotes apoptosis in hepatocellular carcinoma by activating endoplasmic reticulum stress

Abstract

Purpose: In this study we aimed to assess the anti-tumor effect of co-inhibition of Aurora kinase A (AURKA) and heat shock transcription factor 1 (HSF1) on hepatocellular carcinoma (HCC), as well as to explore the mechanism involved.

Methods: Expression of AURKA and HSF1 in primary HCC tissues and cell lines was detected by immunohistochemistry (IHC), qRT-PCR and Western blotting. AURKA was knocked down in HepG2 and BEL-7402 HCC cells using lentivirus-mediated RNA interference. Next, CCK-8, clone formation, transwell and flow cytometry assays were used to assess their viability, migration, invasion and apoptosis, respectively. The expression of proteins related to cell cycle progression, apoptosis and endoplasmic reticulum stress (ERS) was analyzed using Western blotting. In addition, in vivo tumor growth of HCC cells was assessed using a nude mouse xenograft model, and the resulting tumors were evaluated using HE staining and IHC.

Results: Both AURKA and HSF1 were highly expressed in HCC tissues and cells, while being negatively related to HCC prognosis. Knockdown of AURKA significantly inhibited the colony forming and migrating capacities of HCC cells. In addition, we found that treatment with an AURKA inhibitor (Danusertib) led to marked reductions in the proliferation and migration capacities of the HCC cells, and promoted their apoptosis. Notably, combined inhibition of AURKA and HSF1 induced HCC cell apoptosis, while increasing the expression of ERS-associated proteins, including p-eIF2α, ATF4 and CHOP. Finally, we found that co-inhibition of AURKA and HSF1 elicited an excellent in vivo antitumor effect in a HCC mouse model with a relatively low cytotoxicity.

Conclusions: Combined inhibition of AURKA and HSF1 shows an excellent anti-tumor effect on HCC cells in vitro and in vivo, which may be mediated by ERS. These findings suggest that both AURKA and HSF1 may serve as targets for HCC treatment.

Keywords: Apoptosis; Aurora kinase A (AURKA); Endoplasmic reticulum stress; Heat shock transcription factor 1 (HSF1); Hepatocellular carcinoma.