Androgen receptor (AR) expression and immune cell infiltration are thought to be involved in trastuzumab response and may, therefore, be of interest as additional targets for therapy in HER2-positive breast cancer.
The expression of Lin28A and AR in formalin-fixed and paraffin-embedded surgical sections from 305 patients with ER-/Her2+ breast cancer was analyzed by immunohistochemistry, and the co-expression patterns in breast cancer cells were investigated by immunofluorescent staining.
In particular, in ER-positive breast cancer, AR signaling often antagonizes the growth stimulatory effect of ER signaling; in triple-negative breast cancer (TNBC), AR seems to drive tumor progression (at least in luminal AR subtype of TNBC with a gene expression profile mimicking luminal subtypes despite being negative to ER and enriched in AR expression); in HER2-positive breast cancer, in the absence of ER expression, AR signaling has a proliferative role.