Background: Forkhead box K1 (FOXK1) is a transcription factor belonging to the Forkhead box (FOX) family and is closely related to the development of various cancers, but the functional mechanism through which FOXK1 regulates autophagy and epithelial-mesenchymal transition (EMT) in the acidic microenvironment of gastric cancer (GC) remains unclear.

Results: Our results indicated that the inhibition of FOXK1 induced autophagy and thus exerted antimetastatic effects in an acidic microenvironment. The dual inhibition of mammalian target of rapamycin (mTOR) and FOXK1 enhanced autophagy and reversed EMT of acidic GC cells. In addition, FOXK1 activated transcription in conjunction with the MAZ promoter.

Conclusion: Together, our results suggest that FOXK1 can be used as an independent prognostic indicator for GC patients. We also revealed a new strategy involving the cotargeting of FOXK1 and autophagy to reverse the effects of EMT. MAZ is involved in the development and progression of GC as a downstream target of FOXK1.

Methods: Here, the cellular responses to the inhibition of FOXK1 in GC were studied in vivo and in vitro through wound healing assays, transwell assays, Western blotting, laser confocal microscopy and transmission electron microscopy. The molecular mechanisms of FOXK1 and Myc-associated zinc finger protein (MAZ) were studied via chromatin immunoprecipitation sequencing (ChIP-seq), bioinformatics, Western blotting, and quantitative real-time PCR (q-PCR).