OBJECTIVETo investigate the role of the hedgehog (HH) signaling pathway transcription factor glioma-associated oncogene hoinolog 1 (GLI-1) in EGF-regulated enhancement of the invasiveness of the prostate cancer ARCaP(E) cell line in vitro.

METHODSThe expressions of EGFR and GLI-1 in prostate cancer ARCaP(E) cells were analyzed by immunofluorescence staining. ARCaP(E) cells were treated with EGF at 100 ng/ml, followed by detection of the changes in cell morphology and invasiveness, as well as in the expressions of p-ERK, ERK and GLI-1. Migration transwell assay was used to determine the effects of 100 ng/ml EGF and GLI-1 antagonist GANT61 on the invasiveness of the ARCaP(E) cells.

RESULTSBoth EGFR and GLI-1 were expressed in the ARCaP(E) cells. EGF induced morphological transition of epithelial-like ARCaP(E) cells to mesenchymal-like cells, increased their in vitro invasiveness, and significantly upregulated the expressions of p-ERK and GLI-1 in the ARCaP(E) cells (P<0.05). GANT61 significantly inhibited the in vitro invasiveness of the ARCaP(E) cells and reduced the enhancing effect of EGF on their invasiveness (P<0.05).

CONCLUSIONThe results from ARCaP(E) cells shed light on the cross-talk of the HH pathway with the EGF/ERK signaling pathway. GLI-1 might be responsible for EGF-regulated enhancement of the invasiveness of ARCaP(E) cells in vitro.