Inhibition der Tumorzelladhäsion an Extrazellularmatrixkomponenten durch Phospholipide in vitro

Aims: Nidation of floating tumor cells initiates peritoneal carcinosis and limits prognosis of gastrointestinal tumors. Adhesion of tumor cells to extracellular matrix components is a pivotal step in developing peritoneal dissemination of intraabdominal malignancies. Since phospholipids efficaciously prevent peritoneal adhesion formation in numerous animal studies we investigated their capacity to reduce adhesions of gastric and rectal cancer cells to extracellular matrix components. Methods: Human gastric cancer cells (NUGC-4) and human rectal cancer cells (HRT-18) were used in this study. Microtiter plates were coated with collagen IV, laminin and fibronektin. Nonspecific protein binding of the coated wells was blocked by adding 1% BSA (4øC, 12h) and rinsing the wells with Hepes buffer. According to dilution series, 30000 - 70000 tumor cells in 100 æl medium were seeded into each well. Beside the controls, phospholipids were added in concentrations of 0.05, 0.1, 0.5, 0.75, and 1.0mg/100æl medium. After the incubation time of 30 min, attaches cells were fixed and stained with 0.1%crystal violet. The dye was resuspended with 50æl of 0.2%Triton X-100 per well and colour yields were then measured in an ELISA reader at 590 nm. Optical density showed a linear relationship to the amount of cells and was corrected for dying of BSA/polystyrene without cells. Results: The attachment of gastric cancer cells to collagen IV, laminin, and fibronectin could be significantly reduced up to 53% by phospholipid concentrations of 0.5mg/100æl and higher, the attachment of rectal cancer cells could be significantly reduced up to 46% at these phospholipid concentrations. Conclusions: These results, within the scope of additional experimental studies on mice and rats which showed significant reduction of peritoneal carcinosis, demonstrated the capacity of phospholipids in controlling abdominal nidation of tumor cells to ECM components. Lipid emulsions may be a beneficial adjunct in surgery of gastrointestinal malignancies