Identification of androgen-responsive microRNAs and androgen-related genes in breast cancer

Background: Androgen receptors (ARs) are expressed in many breast cancer cells, but the mechanism of action of androgens is not as well-characterized as in other cell types. The study of microRNAs has recently provided with important insights into the biology of hormonedependent cancer. Materials and Methods: We attempted to identify microRNAs induced by dihydrotestosterone in an ARpositive cell line. We examined a possible correlation among microRNAs, target genes, and ARs in breast cancer tissues using immunohistochemistry and laser capture microscopy. Results: Our analysis demonstrated that miR-363 and its possible target IQ motif and WD repeats-1 (IQWD1) are involved in a microRNA-mRNA pathway related to the mechanism of action of androgens. Our analyses showed that a high tumor level of IQWD1 in patients with breast cancer was significantly associated with adverse clinical outcomes. Conclusion: Our findings indicated that the recruitment of IQWD1 to ARs may be a prerequisite for the growth stimulation by androgens through ARs in breast cancer cells.