So it only took three years to start posting blog entries! We have been a little busy I guess...

BRCA1 loss of function is an interesting example of the tissue-specificity of cancers.  BRCA1 is a ubiquitously expressed protein involved in several critical cellular functions, including tumor suppression through involvement of the DNA damage signaling, as well as DNA repair, transcriptional regulation, and maintenance of heterochromatin. Despite these universally critical roles for cellular function, mutations in BRCA1 do not lead to a large spectrum of cancers throughout the body, but rather are associated with specifically cancers of the breast and ovary. Titus et al.  have recently demonstrated that in addition to cancer promotion, age-related decrease of BRCA1 leads to a decline in reproductive performance via decline in oocyte viability in both mouse and humans. The researchers had previously reported that BRCA1 germline mutation carriers had lower responses to ovarian stimulation while undergoing fertility preservation. In their latest work they demonstrate that, in both mice and humans, aging results in an increased incidence of double-stranded breaks in oocytes and a concomitant decrease in expression of DNA repair genes involved in DSB repair, including BRCA1. The results of this study highlight how genes encoding proteins involved in essential cellular functions have exquisitely tissue-specific effects. Curious to know whether changes in regulation of BRCA1 plays a role in breast aging and age-related breast cancers?

- Lorena Mora-Blanco