PubMed · 7990152
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L L Myeroff, S D Markowitz. 1994-12-21. Nm23--into the basement (membrane). https://doi.org/10.1093/jnci%2F86.24.1815
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OBJECTIVE: The metastatic process in epithelial ovarian cancer is thought to involve surface shedding and subsequent dissemination of ovarian cancer cells, facilitated by localized proteolysis at the interface between ovarian cancer cells and peritoneal surfaces. The factors regulating the metastatic process, however, are not well understood. Transforming growth factor-beta (TGF-beta) is a multifunctional peptide that elicits numerous cellular effects pertinent to the metastatic process. The purpose of this study was to evaluate the regulatory role of TGF-beta on metastasis in ovarian cancer. METHOD: We evaluated the effect of TGF-beta on the metastatic characteristics (adhesion, invasion, motility, proteolysis) of five ovarian cancer cell lines (DOV-13 and OVCA 420, 429, 432, and 433), two short-term primary ovarian cancer cell cultures (OVCA 10 and OVCA 208), and five normal ovarian surface epithelial (NOSE) cell cultures (OSE 133, 185, 186, 188, and 189). The effect of TGF-beta on invasion and proteolysis was quantified using a modified Boyden chamber invasion assay, zymography, a coupled colorimetric activity assay, and an HPLC-based quantitation of synthetic substrate cleavage. RESULTS: TGF-beta significantly increased invasion in five of seven ovarian cancer cell lines in amounts ranging from 2- to 20-fold. In contrast, TGF-beta significantly decreased invasion in two of five NOSE isolates by 50 to 80% and had no significant effect on invasion in three. TGF-beta treatment increased matrix metalloproteinase (MMP) expression in OVCA 420 and 433 and DOV-13, resulting in MMP-dependent collagen cleavage and invasive activity. Addition of the MMP inhibitor GI12947 neutralized the enhancing effect of TGF-beta on invasion. TGF-beta had no effect on ovarian cancer cell motility and only increased adhesion in DOV-13. CONCLUSIONS: These data suggest that TGF-beta may enhance the invasiveness of ovarian cancers through induction of MMP activity.
This study reports the presence of oval-shaped pores in the basement membrane of the human bronchial airway that may be used as conduits for immune cells to traffic between the epithelial and mesenchymal compartments. Human bronchial mucosa collected after surgery was stripped of epithelial cells without damaging the basement membrane. Both scanning and transmission electron microscopy showed oval-shaped pores 0.75 to 3.85 microm in diameter in the bronchial basement membrane at a density of 863 pores/mm2. Transmission electron microscopy showed that the pores spanned the full depth of the basement membrane, with a concentration of collagen-like fibers at the lateral edges of the pore. Infiltrating cells apparently moved through the pores, both in the presence and absence of the epithelium. Taken together, these results suggest that immune cells use basement membrane pores as predefined routes to move between the epithelial and mesenchymal compartments without disruption of the basement membrane. As a persistent feature of the basement membrane, pores could facilitate inflammatory cell access to the epithelium and greatly increase the frequency of intercellular contact between trafficking cells.
OBJECTIVES: Degeneration of bioprosthetic heart valves has been suggested to be at least partly an immunogenic reaction toward the xenogeneic tissue. An autologous endothelial lining has been proposed to overcome this problem. We examined in vitro endothelialization of such tissue and retention of endothelial cells after exposure to flow resembling the in vivo situation. METHODS: Cultured human saphenous vein endothelial cells were used to in vitro endothelialize photo-oxidized bioprosthetic heart valves. The endothelialized valves were mounted in a specially designed flow device, creating a pulsatile flow through the valve. Maintenance of a confluent cell layer and deposition of basement membrane markers were determined with immunohistochemical labeling. RESULTS: Labeling of the main components of the basement membrane, laminin and collagen type IV, was verified within 6 hours after in vitro endothelialization. Under static conditions, 4-mm wide denudations were completely re-endothelialized in 4 days, which was similar to the growth rate on gelatin-coated cell culture plastic, which served as a control material. After exposure of endothelialized valves to pulsatile flows for 24 hours (80 beats/min, 3.4 L/min), there were minimal cell losses from the bioprostheses. The cell layer adapted to the pulsatile flow, as verified by rearrangement of morphology and intracellular stress fibers. CONCLUSIONS: This study shows the feasibility of in vitro endothelialization of photo-oxidized bioprosthetic heart valves. The cells are able to withstand a pulsatile flow in vitro, to develop basement membrane-like structures, and to re-endothelialize denuded areas. This technology may be used to enhance the performance of bioprosthetic heart valve prostheses.