Injured tissues favor cancer cell implantation via fibrin deposits on scar zones

AIM: Evaluation of fibrin role on cancer cells implantation in injured tissues and studying the molecular mechanism of cancer cell interaction with the peritoneal damage. MATERIAL AND METHODS: Mouse colon cancer (CT26) and human mesothelial cells (HMCs) were used. CT26 cells were implanted on injured peritoneal zones. Icodextrin was used as a lubricant. For in vitro studies, fibrin clots from human plasma were used. The cell-fibrin interaction was observed by optical, electronic, and confocal microscopies. Aprotinin was used as a plasmin inhibitor. Hemostasis impact quantified by (1) the fibrin degradation product D-Dimer and PAR expression in HMCs; (2) the expression of plasminogen activator (PA) and its inhibitor (PAI-1) in cancer cells by qPCR and in supernatants through ELISA after in vitro HMC incubation with 2U of thrombin for 24 h. RESULTS: (i) Cancer cell lines were adhered and implanted into the wound area in vivo in both the incision and peeling zones of the peritoneum and on the fibrin network in vitro. (ii) Icodextrin significantly inhibited cancer nodule formation in the scar and the incision or peritoneal damaged zones after surgery. (iii) In in vitro studies, cancer cell interaction with the fibrin clot generated a lysed area, causing an increase in plasmin-dependent fibrinolysis measured by D-dimer levels in the supernatants that was inhibited by aprotinin. (iv) Aprotinin inhibited cell-fibrin interaction and invasion. (v) Thrombin upregulates PAI-1 and downregulates PA expression in HMC. CONCLUSION: Injured tissues favor cancer cell implantation through generated fibrin. Fibrin-cancer cells adhesion can be inhibited by icodextrin.