Expression array analysis of the hepatocyte growth factor (HGF) invasive program

HGF stimulates mitogenesis, motogenesis and morphogenesis in most epithelial target cells. Selective inhibition of HGF signaling blocks spontaneous metastasis, but not primary tumor growth, in the prostate adenocarcinoma derived PC3M cell xenograft model. To identify the HGF activated genes and pathways that contribute to cell motility and invasion, i.e. the HGF invasive program, expression profiling was performed on PC3M cells that were untreated or were treated with human HGF (hHGF), which drives all 3 primary activities, or with human HGF/NK2 (hNK2) or murine HGF (mHGF), which drive motility and invasion but not proliferation in human cells. Differences in gene expression profiles among these four groups were used to distiniguish between events associated with invasion (resulting from hNK2 or mHGF treatment) from those associated with the combination of invasion and proliferation (resulting from hHGF treatment). PC3M cells were left untreated or treated with hHGF, hNK2 or mHGF for 8, 16 or 32 hours prior to RNA extraction, cDNA preparation and array hybridization.