Figure 4.

IHC analysis of (A) TTF-1, (B) NKX3.1, (C) SCG3, and (D) HuD in CRPC metastases (n=155). We observed increased expression TTF-1 in NE CRPC, a loss of NKX3.1 expression in AR− NE CRPC, increased expression of SCG3 in NE CRPC, and an increase in expression of HuD in AR− NE CRPC. The difference in the expression of each of these proteins underlines the biology associated with AR+ and AR− neuronal phenotype in CRPC metastases. Representative pictures of stained metastases are shown. TTF-1 and NKX3-1 staining was mainly nuclear (A, a–d) and (B, a–d) respectively. SCG3 was cytoplasmic with various staining patterns: sporadic intensely stained single cells (C, a); an apocrine pattern, with positive stained cytoplasmic membrane-bound vesicles budding in the lumen (C, b); a mixture of apocrine pattern with cytoplasmic positivity (C, c); and a homogeneous cytoplasmic staining pattern (C, d). HuD staining was mainly nuclear (D, a–d).