Gene expression signature of atypical breast hyperplasia and regulation by SFRP1.

Background: Atypical breast hyperplasias (AH) have a 10-year risk of progression to invasive cancer estimated at 4-7%, with the overall risk of developing breast cancer increased by ~ 4-fold. AH lesions are estrogen receptor alpha positive (ERα+) and represent risk indicators and/or precursor lesions to low grade ERα+ tumors. Therefore, molecular profiles of AH lesions offer insights into the earliest changes in the breast epithelium, rendering it susceptible to oncogenic transformation.

SKP2 overexpression is associated with increased serine 10 phosphorylation of p27 (pSer10p27) in triple-negative breast cancer.

S-phase kinase-associated protein 2 (SKP2) is an important cell cycle regulator, targeting the cyclin-dependent kinase (CDK) inhibitor p27 for degradation, and is frequently overexpressed in breast cancer. p27 regulates G1 /S transition by abrogating the activity of cyclin/CDK complexes. p27 can undergo phosphorylation at serine 10 (pSer10p27).