IGF2BP3 promotes gastric cancer progression by inhibiting ferroptosis through ETV4-mediated regulation of GCH1.

BACKGROUND

Ferroptosis can be inhibited by insulin-like growth factor 2 mRNA-binding protein 3 (IGF2BP3) in cancers. ETS variant transcription factor 4 (ETV4) is aberrantly expressed in various cancers. Elevated transcription of guanosine triphosphate cyclohydrolase 1 (GCH1) contributes to tumor malignancy. This study investigated the involvement of IGF2BP3, ETV4, and GCH1 in ferroptosis in gastric cancer (GC).

METHODS

GC cells and tissue samples were used to detect IGF2BP3, ETV4, and GCH1 expression. The relationships between IGF2BP3, ETV4, and GCH1 were assessed using RNA immunoprecipitation assay, chromatin immunoprecipitation assay, and dual-luciferase reporter assay. BALB/c nude mice were utilized to establish GC tumor xenografts. Cell cloning and Transwell were used to detect the proliferation, migration, and invasion of cells.

RESULTS

IGF2BP3 and ETV4 were upregulated in GC. IGF2BP3 regulated ETV4 protein level by mediating its mRNA stability. Knockdown of ETV4 inhibited GC cell proliferation, migration, and invasion, and promoted their ferroptosis. ETV4 also promoted the transcription of GCH1 by directly binding to its promoter region. GCH1 overexpression diminished the facilitating effect of ETV4 knockdown on ferroptosis in GC. Overexpression of GCH1 also eliminated the promoting impact of IGF2BP3 knockdown on GC cell proliferation, migration, and invasion. Lastly, inhibition of GCH1 reversed the promoting effect of IGF2BP3 overexpression on GC tumor growth in vivo.

CONCLUSIONS

IGF2BP3 promotes tumor growth and inhibits ferroptosis in GC by regulating ETV4, while ETV4 promotes GCH1 expression by direct interaction with its promoter. GCH1 overexpression counteracts the effects of ETV4 and IGF2BP3 on GC.