Deacetylation of ANXA2 by SIRT2 desensitizes hepatocellular carcinoma cells to donafenib via promoting protective autophagy.

Hepatocellular carcinoma (HCC) is one of the most lethal forms of cancer globally. HCC cells frequently undergo macroautophagy, also known as autophagy, which can lead to tumor progression and chemotherapy resistance. Annexin A2 (ANXA2) has been identified as a potential therapeutic target in HCC and is involved in the regulation of autophagic process. Here, we for the first time showed that ANXA2 deacetylation plays a crucial role in donafenib-induced autophagy. Mechanistically, donafenib increased SIRT2 activity via triggering both SIRT2 dephosphorylation and deacetylation by respectively downregulating cyclin E/CDK and p300. Moreover, elevation of SIRT2 activity by donafenib caused ANXA2 deacetylation at K81/K206 sites, leading to a reduction of the binding between ANXA2 and mTOR, which resulted in a decrease of mTOR phosphorylation and activity, and ultimately promoted protective autophagy and donafenib insensitivity in HCC cells. Additionally, ANXA2 deacetylation at K81/K206 sites was positively correlated with poor prognosis in HCC patients. Meanwhile, we found that selective inhibition of SIRT2 increased the sensitivity of donafenib in HCC cells by strengthening ANXA2 acetylation. In summary, this study reveals that donafenib induces protective autophagy and decreases its sensitivity in HCC cells through enhancing SIRT2-mediated ANXA2 deacetylation, which suggest that targeting ANXA2 acetylation/deacetylation may be a promising strategy for improving the sensitivity of donafenib in HCC treatment.