ABSTRACT
Transthyretin amyloid cardiomyopathy (ATTR-CM) is a progressive systemic disease involving the extracellular deposition of misfolded transthyretin protein. The hereditary subtype is caused by mutations in the transthyretin (TTR) gene. An estimated 2-3% of individuals of African American (AA) ancestry carry the p.Val142Ile (V142I, also referred to as V122I) TTR pathogenic variant. The non-specific clinical nature of ATTR-CM makes it challenging to diagnose clinically, and the high allele frequency of TTR V142I suggests that many patients with hereditary ATTR-CM may not have been tested. An analysis of electronic health record data from over 13,000 AA patients with a diagnostic code for heart disease or arrhythmia who also had additional amyloid-related findings were not diagnosed with amyloidosis at higher rates than those with heart failure or arrhythmia who did not have additional amyloid-related clinical diagnoses. Similarly, after genotyping 666 AA patients with heart failure or arrhythmia, TTR V142I carriers appeared to be clinically indistinguishable based on amyloid-related non-cardiac diagnoses from those who did not carry the allele. No additional TTR gene sequence variants were found in the TTR wildtype V142V patients with heart failure or arrhythmia who had additional amyloid-related diagnoses. Genetic testing for ATTR-CM may be important for timely diagnosis.
ABSTRACT
Two major risk factors for ovarian cancer include loss-of-function mutations in the BRCA1 (breast cancer 1, early onset) gene and aspects of estrogen metabolism. Modulation of the levels of the normal BRCA1 allele and estrogen receptor expression may therefore be a preventive strategy. Consensus binding motifs for the bile acid-responsive transcription factor farnesoid X receptor were identified in the BRCA1 and estrogen receptor 1 (ESR1) and estrogen receptor 2 (ESR2) genes, supported by chromatin immunoprecipitation sequencing data. Two major bile acids, deoxycholic acid (DCA) and chenodeoxycholic acid (CDCA), resulted in a greater than four-fold induction of BRCA1 transcript levels at 10 µmol/l and a greater than six-fold induction at 50 µmol/l relative to untreated control OVCAR3 ovarian cancer cells. Conversely, CDCA and DCA at 10 µmol/l resulted in about a 75% decrease in ESR1 expression in response to 10 µmol/l CDCA and DCA and close to 90% reduction with 50 µmol/l CDCA and DCA. Bile acids had no effects on ESR2 gene transcript levels. The inverse regulation of BRCA1 and ESR1 gene expression in response to physiological levels of bile acids could have important implications for disease penetrance and chemoprevention strategies in carriers of BRCA1 mutations.
