Valproic acid targets HDAC1/2 and HDAC1/PTEN/Akt signalling to inhibit cell proliferation via the induction of autophagy in gastric cancer

: Valproic acid (2-propylpentanoic acid, VPA) has been widely used as an anticonvulsant drug and is a choice drug for seizure treatment. VPA is also used as a short-chain fatty acid HDAC inhibitor that affects proliferation and differentiation and induces cell apoptosis in both solid and haematologic malignancies. Here, we observed that VPA treatment inhibited HDAC1/2 activity and induced autophagy in gastric cancer cells, leading to apoptosis. VPA-induced apoptosis occurred through inhibition of the HDAC1/PTEN/Akt signalling pathway and involved alterations in Bcl-2 and Beclin-1. The antitumour effects of VPA were verified in vivo using SGC-7901 xenograft models. Moreover, we evaluated the expression of HDAC1/2 in gastric cancer patient samples and revealed a positive correlation between HDAC1/2 overexpression and poor prognosis. These findings indicate that VPA may serve as a potential therapeutic agent for gastric cancer and that HDAC1/2 might be a promising therapeutic biomarker for the disease.