HIP1 mediates prostate carcinogenesis and progression through STAT3 signalling

Overexpression of HIP1 has been associated with fibroblast transformation, increasing grades of prostate cancer (CaP), and biochemical relapse. Here we demonstrate cellular transformation and phenotypic effects of HIP1 overexpression in a benign prostate epithelial cell line to be dependent on STAT3 signalling. In vivo xenografts confirmed the cellular transformation phenotype and revealed serum GDF15 to be a marker of CaP in our model. STAT3 signalling was in part, dependent on HIP1 expression, in a highly invasive, metastatic and androgen receptor (AR) negative DU145 cell line, Immunohistochemistry of a large prostate tissue microarray (TMA) revealed increased HIP1 and reciprocal GDF15 expression to adversely affect outcome warranting further studies to assess HIP1 and GDF15 as biomarkers for detection and prognostication of CaP. Gene expression of PNT1a cells stably overexpressing HIP1 protein and LNCaP cells transiently overexpressing HIP1 protein were compared with their respective empty vector control cell lines using the illumina expression array platform. There were six biological replicates for each of the four different groups.