Purpose: Hepatocyte growth factor/scatter factor (HGF/SF) is known to increase the invasiveness and migration of cancer cells in vitro and induce angiogenesis. This study examined if inhibition of HGF/SF receptor expression by cancer cells and HGF/SF expression by stromal fibroblasts affects the growth of mammary cancer. Experimental Design: Transgenes encoding ribozymes to specifically target human HGF/SF receptor (pLXSN-MET) or HGF/SF (pLXSN-HGF) were constructed using a pLXSN retroviral vector. Human mammary cancer cells MDA MB 231 was transduced with pLXSN-MET (MDA+/+). A human fibroblast cell line MRC5, which produces bioactive HGF/SF, was transduced with pLXSN-HGF (MRC5+/+). These cells were used in a nude mice breast tumor model. Results: HGF receptor in MDA+/+ cells and HGF in MRC5+/+ cells were successfully removed with respective ribozymes as shown by reverse transcription-PCR and Western blotting, respectively. MDA +/+ was found to have reduced invasiveness when stimulated with HGF/SF. MRC5+/+ exhibited a significant reduction in HGF/SF production. When injected into athymic nude mice, MDA+/+ exhibited a slower rate of growth, compared with the wild type (MDA-/-), and the cells transduced with control viral vector (MDA+/-). The growth of MDA-/- tumor was significantly enhanced when coimplanted with wild-type MRC5 (MRC5-/-), and the stimulatory effect was reduced when MRC5+/+ cells were coimplanted instead of MRC5-/-. The reduction of tumor growth was accompanied by reduction of angiogenesis, as demonstrated by the staining of VE-cadherin in primary tumor tissues. Conclusions: Retroviral ribozyme transgenes targeting HGF/SF in fibroblasts or its receptor cMET in mammary cancer cells can reduce the growth of mammary cancer and associated angiogenesis by inhibiting paracrine stromal-tumor cell interactions.
|Original language||English (US)|
|Number of pages||8|
|Journal||Clinical Cancer Research|
|State||Published - Nov 1 2003|
ASJC Scopus subject areas
- Cancer Research