Mammary gland tissue changes appearance and functionality in different sequential steps. The tissue of virgin, pregnant, or lactating mammary glands changes controlled by finely regulated physiological processes. A fourth stage (involution), triggered upon weaning, involves remodeling, and the gland regresses to resemble a prepregnant stage. This highly complex process characterized by a high degree of epithelial cell death and tissue remodeling can be divided into phases, which can be independent of each other. The present article describes a variety of signaling pathway components, transcription factors, and mRNA stabilization proteins that play a role in the regulation of cell fate during the involution process. These molecular actors are finely related in health to trigger the delicate mechanism that govern involution after weaning, leaving the gland in a latent stage until needed again. Importantly, it has been shown that this process may contribute to cancer development in the years following childbirth, mainly because of the involvement of inflammatory and remodeling factors.
Part of the book: Current Topics in Lactation
In the human genome, BRCA1 and BRCA2 (for BReast CAncer 1 and 2) genes encode for proteins involved in several functions that are crucial for the maintenance of genome stability and integrity. They participate in DNA damage response and repair pathways and, therefore, act as tumor suppressor genes. Mutations in these genes, which are located in chromosomes 17q21 and 13q13 respectively, are responsible for a great fraction of inherited breast and ovarian cancers, as well as other pathologies, such as Fanconi Anemia. Approximately 30 years ago, a report from a group of the School of Public Health at the University of California about a hypothetical gene that led to predisposition to early-onset breast cancer in certain families changed the history of breast cancer research, diagnosis, and prevention. Nowadays, the accessibility of genetic testing and the availability of different approaches as wide coverage screenings, prophylactic mastectomies, and risk-lowering drugs benefits BRCA1 and BRCA2 mutation carriers enormously. This chapter summarizes the unique trajectory of BRCA research and its scientific and social implications.
Part of the book: BRCA1 and BRCA2 Mutations