Lactation opposes pappalysin-1-driven pregnancy-associated breast cancer.

ABSTRACT: Pregnancy is associated with a transient increase in risk for breast cancer. However, the mechanism underlying pregnancy-associated breast cancer (PABC) is poorly understood. Here, we identify the protease pappalysin-1 (PAPP-A) as a pregnancy-dependent oncogene. Transgenic expression of PAPP-A in the mouse mammary gland during pregnancy and involution promotes the deposition of collagen. We demonstrate that collagen facilitates the proteolysis of IGFBP-4 and IGFBP-5 by PAPP-A, resulting in increased proliferative signaling during gestation and a delayed involution. However, while studying the effect of lactation, we found that although PAPP-A transgenic mice lactating for an extended period of time do not develop mammary tumors, those that lactate for a short period develop mammary tumors

SUBMITTER: Takabatake Y 

PROVIDER: S-EPMC4818749 | biostudies-literature | 2016 Apr

REPOSITORIES: biostudies-literature