Loss of the transforming growth factor-? effector ?2-Spectrin promotes genomic instability.

ABSTRACT: Exposure to genotoxins such as ethanol-derived acetaldehyde leads to DNA damage and liver injury and promotes the development of cancer. We report here a major role for the transforming growth factor ?/mothers against decapentaplegic homolog 3 adaptor ?2-Spectrin (?2SP, gene Sptbn1) in maintaining genomic stability following alcohol-induced DNA damage. ?2SP supports DNA repair through ?2SP-dependent activation of Fanconi anemia complementation group D2 (Fancd2), a core component of the Fanconi anemia complex. Loss of ?2SP leads to decreased Fancd2 levels and sensitizes ?2SP mutants to DNA damage by ethanol treatment, leading to phenotypes that closely resemble those observed in animals lacking both aldehyde dehydrogenase 2 and Fancd2 and resemble human fetal alcohol syndrome. Sptbn1-deficient cells are hypersensitive to DNA crosslinking agents and have defective DNA double-strand break repair that is rescued by ectopic Fancd2 expression. Moreover, Fancd2 transcription in response to DNA damage/transforming growth factor ? stimulation is regulated by the ?2SP/mothers against decapentaplegic homolog 3 complex.Conclusion: Dysfunctional transforming growth factor ?/?2SP signaling impacts the processing of genotoxic metabolites by altering the Fanconi anemia DNA repair pathway. (Hepatology 2017;65:678-693).

SUBMITTER: Chen J 

PROVIDER: S-EPMC5432427 | biostudies-literature | 2017 Feb

REPOSITORIES: biostudies-literature