Endocrine Abstracts

Prostate cancer (PCa) is one of the leading causes of tumor death in Western countries. Modifications in expression and functional alterations that involve the androgen receptor (AR) have been implicated in the progression of PCa and in the development of androgen independence; however, the role of AR in these processes is still debated, as contrasting results have been reported in several studies evaluating the relation between AR expression and disease progression (Tamburrino et al., 2012). Such evaluations are performed in PC specimens where, however, tumor tissue may be mixed to stromal and normal. There is now evidence in the literature that AR role in PCa may vary depending on its location. Indeed, studies performed in animal models (Niu et al., 2008) pointed out the different role of epithelial (protective toward a malignant phenotype) vs stromal (leading to tumor aggressiveness) AR in PCa. The present study was undertaken to evaluate AR, EGFR, PSA and PTEN mRNA expression in stromal and epithelial compartments of PCa specimens following careful microdissection.

So far we have analyzed 130 microdissected samples from 20 patients and further analyses are in progress. Preliminary results indicate that AR expression is correlated to that of EGFR in epithelial (r=0.98, P<0.0001) but not in stromal compartment. A similar correlation is found between AR and PSA in epithelial compartment (r=0.67, P<0.002). PTEN expression tends to decrease and to become undetectable in high-grade tumors as expected. AR expression appears to be lower in microdissected carcinoma areas with higher Gleason scores. In few patients with locally invasive tumors AR expression is higher in stromal respect to epithelial compartment.

In conclusion, evaluation of AR expression in microdissected PCa specimens may reveal new insights on the role of the steroid receptor in PCa progression.