RESUMO
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 ß/mothers against decapentaplegic homolog 3 adaptor ß2-Spectrin (ß2SP, gene Sptbn1) in maintaining genomic stability following alcohol-induced DNA damage. ß2SP supports DNA repair through ß2SP-dependent activation of Fanconi anemia complementation group D2 (Fancd2), a core component of the Fanconi anemia complex. Loss of ß2SP leads to decreased Fancd2 levels and sensitizes ß2SP 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 ß stimulation is regulated by the ß2SP/mothers against decapentaplegic homolog 3 complex. CONCLUSION: Dysfunctional transforming growth factor ß/ß2SP signaling impacts the processing of genotoxic metabolites by altering the Fanconi anemia DNA repair pathway. (Hepatology 2017;65:678-693).
Assuntos
Proteína do Grupo de Complementação D2 da Anemia de Fanconi/genética , Instabilidade Genômica/genética , Prenhez , Espectrina/genética , Fator de Crescimento Transformador beta2/genética , Análise de Variância , Animais , Animais Recém-Nascidos , Dano ao DNA/genética , Reparo do DNA/genética , Etanol/farmacologia , Feminino , Transtornos do Espectro Alcoólico Fetal/genética , Transtornos do Espectro Alcoólico Fetal/patologia , Humanos , Imuno-Histoquímica , Peroxidação de Lipídeos/genética , Camundongos , Camundongos Transgênicos , Gravidez , Reação em Cadeia da Polimerase em Tempo Real/métodos , Transdução de SinaisRESUMO
BACKGROUND: Sentinel lymph node biopsies (SLNB) are used to detect axillary metastases as an important prognostic indicator for breast cancer patients. Bone marrow micrometastases (BMM) have also been shown to predict prognosis. This study examines whether SLNB and BMM are associated. STUDY DESIGN: A retrospective analysis was performed on 124 stages I to III breast cancer patients treated with mastectomy or lumpectomy, SLNB, and bone marrow aspiration between 1997 and 2003. SLNB were examined for the presence of metastases by hematoxylin and eosin (H&E) stains and also by immunohistochemistry (IHC) for lymph nodes negative by H&E. The kappa statistic was used to evaluate the association (agreement) between SLNB and BMM. RESULTS: In this study population, 36 patients (29%) had micrometastases detected in their bone marrow, and 51 patients (41%) had positive sentinel lymph nodes. Of the patients with positive BMM (n = 36), 53% (19 of 36) had positive SLNB (14 of 19 by H&E and 5 of 19 by IHC). In patients with negative BMM (n = 88), 36% (32 of 88) had a positive SLNB (27 of 32 by H&E and 5 of 32 by IHC). The kappa statistic and associated 95% confidence interval indicated poor agreement between SLNB and BMM (kappa = 0.15; 95% CI = -0.03, 0.32). CONCLUSIONS: There was poor agreement between axillary metastases and micrometastases detected in the bone marrow. This study suggests that BMM and axillary metastases are not concordant findings in most patients.