Moreover, brain dissemination is probably the result of progressive dedifferentiation of primary tumor, shown by reduction of ER and AR expression in metastases.
Strikingly, 83% of mice with PIN lesions exhibited metastases to draining lymph nodes, marked by relatively differentiated tumor cells expressing markers of basal (p63, cytokeratin 14) and luminal (cytokeratin 8 and androgen receptor) epithelial cells, although none expressed the basal marker, cytokeratin 5.
All other correlations of AR expression in primary tumors and metastases with quantitative (age, prostate cancer volume, number of metastases) or categorical (tumor stage, Gleason score of the primary tumor and metastases) tumor characteristics or with survival were insignificant.
These results suggest that, similarly to Snail and Twist, the activated AR can downregulate E-cadherin expression to promote the activation of epithelial-mesenchymal transition and tumor metastasis.
Although most metastases (21/22, 95%) had concordant AR expression with the primary tumors, one treatment-naïve tumor (5%) had complete loss of AR immunoexpression in the metastasis without detectable molecular alterations in AR or AR co-regulators.
The concordance of <sup>18</sup>F-FDHT and <sup>18</sup>F-FES uptake on PET with immunohistochemical expression of AR and ER in biopsies of corresponding metastases was analyzed.
We did not find any GATA3 or AR expression in the metastases from endometrial or salivary gland carcinomas, while GATA3 expression was seen in the majority of metastases from urothelial or breast carcinomas.
The progression from low-grade to high-grade prostate carcinoma and metastases is mediated by a selective down-regulation of the androgen receptor target genes that inhibit proliferation, induce differentiation, or mediate apoptosis.
Body mass index (P = .023) and DACH1 (P = .034) were correlated with MBC prognosis, whereas the expression of AR (P = .049), SIX1 (P = .048), surgery (P < .001), and chemotherapy (P = .001) were important for FBC in addition to already known factors: tumor size and location, TNM stage (lymph nodes and organ metastasis), radiotherapy, and ER and human epidermalgrowth factor receptor-2 (HER2) expression.