Dominant negative Met reduces tumorigenicity-metastasis and increases tubule formation in mammary cells

Abstract

Activation of the Met tyrosine kinase growth factor receptor by its ligand HGF/SF has been shown to increase in vitro invasiveness in epithelial cell lines. To study the eect of Met-HGF/SF signaling in breast cancer cells, we transfected met, hgf/sf and dominant negative (DN) forms of met into the poorly dierentiated metastatic murine mammary adenocarcinoma cell line DA3. These cells express moderate levels of endogenous Met, which is rapidly phosphorylated in response to HGF/SF treatment. Met+hgf/sf transfection results in signi®cantly increased tumorigenic and metastatic activity in vivo accompanied by reduced tubule formation. DA3 cells transfected with DN forms of Met (DN-DA3) exhibit reduced Met phosphorylation following exposure to HGF/SF. Furthermore, as compared to the parental cells, the DN-DA3 cells exhibit diminished in vitro scattering and invasiveness, while in vivo they display greatly reduced tumorigenicity and spontaneous metastasis. Tumors emanating from DN-DA3 cells injected to BALB/C mice are highly dierentiated and display extensive tubule formation. These results suggest that Met-HGF/SF signaling is a determining factor in the delicate balance between dierentiation/tubule formation and tumorigenicity-metastasis.

A Novel Recombinant Soluble Splice Variant of Met Is a Potent Antagonist of the Hepatocyte Growth Factor/Scatter Factor-Met Pathway

“…To examine the effect of Cgen-241A on cell invasion, we used DA3 cells, which are derived from a mouse mammary carcinoma. It has been shown previously that HGF/SF induces invasion of these cells, whereas inhibition of HGF/SF-Met pathway reduces this effect (24). HGF/SF and different concentrations of Cgen-241A were placed in the lower wells of a chemotaxis chamber, while DA3 cells were placed in the upper wells and allowed to invade to the lower wells through a Matrigel-coated filter.…”

“…MKN45 and SUIT-2 cells were obtained from the Japanese Collection of Research Bioresources. D1-DMBA-3 (DA3) cells were derived from poorly differentiated mammary adenocarcinoma using dimethylbenzanthracene (24). All cell lines were cultured as recommended by the provider.…”

Mimp, a Mitochondrial Carrier Homologue, Inhibits Met-HGF/SF-Induced Scattering and Tumorigenicity by Altering Met-HGF/SF Signaling Pathways

“…One of the well-documented responses of several cell lines, including DA3, to HGF/SF is cellular scattering (27). To study the effect of Mimp induction on scattering, iMimp-DA3 cells were plated in the presence of 100 or 500 ng/mL doxycycline for 2 days to allow for Mimp expression and then harvested and plated in quadruplicate Figure 4.…”

Role of Hepatocyte Growth Factor and c-Met Receptor in Neoplastic Conditions of Salivary Glands

“…HGF is also needed for morphogenesis and homeostasis in various normal developmental stages of the body, and during fetal development [47]. In addition, HGF is typically represented in the induction of tubular forms in neoplasms such as adenocarcinomas [13]. Knockout mice for HGF display placental defects, reduced liver volume and abnormalities of skeletal muscle including the tongue, and invariably die before birth [32,43].…”