HEPATOCYTE GROWTH-FACTOR (HGF), KERATINOCYTE GROWTH-FACTOR (KGF), ANDTHEIR RECEPTORS IN HUMAN BREAST CELLS AND TISSUES - ALTERNATIVE RECEPTORS

We sought to determine whether the hepatocyte growth factor/scatter fa ctor (HGF/SF)- and keratinocyte growth factor-receptor systems were ex pressed in normal breast cells, breast carcinoma cell lines, normal br east tissues, and breast cancer tissues. Reverse transcriptase-polymer ase chain reaction and hot blotting were used to detect HGF, HGF/SF (m et) receptor, KGF, and KGF receptor mRNAs in human mammary epithelial (HME) and stromal (HMS) cells. We also examined breast carcinoma (MDA- MB-157, SCC 38, and SCC 70) and spontaneously immortalized breast epit helial (HMT 3522) cell lines, as well as normal breast and breast carc inoma tissues. PCR products were also confirmed by nucleic acid sequen cing. The effects of HGF and KGF, compared to EGF and heparin-binding EGF, on the proliferation of normal human mammary epithelial cells in serum-free defined medium was determined by cell counting. HGF and KGF mRNAs were detected in HMS cells, but not HME cells. KGF receptor mRN A was detected in HME cells, but not HMS cells. HGF/SF receptor mRNA w as detected in both HME and HMS cells. mRNAs were also detected in nor mal breast and breast carcinoma tissues, as well as breast carcinoma a nd transformed breast epithelial cell lines. Alternative cDNA sequence s that are predicted to code for a soluble KGF receptor and a membrane bound, truncated HGF/SF receptor were detected in breast epithelial c ells and breast tissues. HGF and KGF maintained viability and stimulat ed proliferation of HME cells.