IGF2BP2 promotes cancer progression by degrading the RNA transcript encoding a v-ATPase subunit

Area of Science:

• Molecular Biology
• Cancer Biology
• Biochemistry

Background:

• Insulin-like growth factor 2 mRNA-binding protein 2 (IGF2BP2) is implicated in tumor promotion, but its regulatory mechanisms in RNA metabolism are unclear.
• The vacuolar ATPase (v-ATPase) plays a critical role in cellular functions, including lysosomal activity.

Purpose of the Study:

• To elucidate the regulatory mechanisms of IGF2BP2 in RNA metabolism.
• To investigate the role of IGF2BP2 in the stability of the ATP6V1A transcript and its impact on cancer progression.

Main Methods:

• RNA immunoprecipitation assays to identify IGF2BP2 binding targets.
• Analysis of IGF2BP2 acetylation and deacetylation by SIRT1.
• Assessment of ATP6V1A transcript stability and v-ATPase function.
• Characterization of the cellular secretome, including exosome production.

Main Results:

• IGF2BP2 binds to the 3' untranslated region of the ATP6V1A transcript.
• SIRT1-mediated deacetylation of IGF2BP2 prevents ATP6V1A transcript degradation.
• Low SIRT1 levels result in acetylated IGF2BP2, recruiting XRN2 nuclease and degrading ATP6V1A.
• Impaired lysosomal activity and increased exosome production in breast cancer cells with low SIRT1 contribute to tumor survival and invasiveness.

Conclusions:

• SIRT1-regulated IGF2BP2 acetylation controls ATP6V1A mRNA stability, impacting lysosomal function.
• This pathway represents a novel mechanism by which IGF2BP2 promotes tumor progression.
• Targeting the IGF2BP2-SIRT1 interaction could offer therapeutic strategies for breast cancer.