To get more insight into the role of AR in breast cancer, we additionally performed a retrospective pooled analysis to determine the prognostic value of the AR using mRNA profiles of 7270 primary breast tumors.
It has also been documented that AR is expressed in more than 60% of breast tumors, which promotes the growth of estrogen receptor-negative (ER<sup>-</sup>)/AR-positive (AR<sup>+</sup>) breast cancer cells.
Recent advances in the molecular classification of breast tumours have uncovered a subset of breast tumours associated with high expression of androgen receptor mRNA including the so-called 'luminal androgen receptor (LAR) tumours' and 'molecular apocrine tumours' (MATs).
Association of repeat polymorphisms in the estrogen receptors alpha, beta (ESR1, ESR2) and androgen receptor (AR) genes with the occurrence of breast cancer.
In AR negative breast tumours, mutation screening identified the same mutation (T105A) in the 5'UTR of two AR negative breast cancer patients but not reported in the normal human population.
In order to define AR in breast cancer, 67 primary breast tumours and 8 normal breast samples as control tissue were analysed for AR expression at the mRNA and protein levels using RT-PCR and Western blotting, respectively.