Hepatocyte growth factor expression in normal lung and lung cancer

Hepatocyte Growth Factor (HGF) is a recently identified growth factor that is believed to be produced by cells of mesenchymal origin and to act on cells of epithelial origin HGF induces cell movement and cell proliferation There have been conflicting reports it the cell types that produce HGF in Ihe lung. To determine the type of cells in the lung tht express message for HGF and HGF receptor {c-met}. a new method of direct m situ reverse transcnptton-polymerase chain reaction (Direct m situ RT-PCR) was used in visualize cDNA amplified from mRNA m sections of human airway and human lunq tumor tissue The reverse transcription was accomplished with random hoxsmers and reverse transcnptase In situ amplification of cDNA was carried out by primers thai span an mlron in the genomic DMA with direct biotin-dUTP labeling. The detection was performed using streptavidm, biotinylated alkaline phosphase and NBT/BCIP that produces a dark blue color Preliminary results show that the cells in the normal airway of mesenchymal origin, such as fibroblasts and smooth muscle, as well as macrophages, express message for HGF but not HGF receptor.The reverse ts true of surface epithelial cells within the airway in tumors, stromal cells express message for HGF but not HGF receptor, while the carcinoma cells within the tumor expressed message (or HGF receptor but not HGF itself. These observations confirm that HGF is a paracnne factor within the lung and that neither normal nor malignant airway epithelial cells produce HGF Supported by the American Cancer Society,.