An early age of pregnancy (25 years and younger) is known to reduce the overall risk of breast cancer by over 30%, suggests findings of a recent study.
CSHL Assistant Professor Camila dos Santos spent several years teasing out the molecular details behind the protective effects of pregnancy.
She discovered that one-way breast cells protect themselves from cancer after pregnancy in mice is to tuck away a particularly potent cancer gene, cMYC, where it cannot cause harm.
Another trick is to keep breast cells suspended in a state of "pre-senescence," a moment in the cell's life cycle between dying, living, and potential cancer.
These findings provide new insights into future cancer treatment and better ways to identify risk before a tumour develops.
Pregnancy blocks the deadly action of cMYC by rolling the gene away.
Dos Santos suggests a familiar image: Pregnancy turns off the cMYC gene and turns on another set of genes that promotes senescence.
Cells repeat the pattern open and closed DNA in subsequent pregnancies.