Inflammatory cytokines stimulate the adhesion of colon carcinoma cells to mesothelial monolayers

Surgical handling of the peritoneum causes an inflammatory reaction, during which a potentially lethal cocktail of active mediators is produced, including cytokines and growth factors. The aim of this study was to investigate the effects of inflammatory cytokines on the interaction between tumor and mesothelial cells. Tumor cell adhesion to a mesothelial monolayer was assessed after preincubation of the mesothelium with interleukin (IL)-1beta, IL-6, and tumor necrosis factor (TNF)-alpha. Preincubation of the mesothelial monolayer with IL-1beta or TNF-alpha resulted in enhanced tumor cell adhesion of Caco2 and HT29 colon carcinoma cells. The amount of stimulation for the Caco2 cells was between 20% and 40% and for HT29 cells between 30% and 70%. Blocking experiments with anti-IL-1beta and anti-TNF-alpha resulted in significant inhibition of the cytokine-stimulated tumor cell adhesion. The presented results prove that IL-1beta and TNF-alpha are significant stimulating factors in tumor cell adhesion in vitro and may therefore account for tumor recurrence to the peritoneum in vivo.

The post-surgical inflammatory response provokes enhanced tumour recurrence: a crucial role for neutrophils

BACKGROUND/AIMS

Peritoneal trauma activates a cascade of peritoneal defence mechanisms responsible for postoperative intra-abdominal tumour recurrence. After peritoneal trauma, inflammatory cells and soluble factors are present in the abdominal cavity and can be captured in lavage fluids. The present study evaluated which component enhances intra-abdominal tumour recurrence. Furthermore, we evaluated which inflammatory cells are present and studied the influence of anti-neutrophil serum (ANS) on peritoneal tumour recurrence.

METHODS

In a peritoneal trauma model in rats, postoperative lavage fluids were collected and separated into cellular and supernatant components. Both components were injected in naïve rats together with CC531s colon carcinoma cells. In a second experiment, rats were treated with one or three doses of ANS.

RESULTS

Intraperitoneal injection of naïve recipients with inflammatory cells or supernatant resulted in significant tumour recurrence. Severe peritoneal trauma provoked significant intra-abdominal neutrophil influx which could be prevented by ANS. Treatment with one dose did not affect blood cell counts and significantly reduced tumour recurrence. Treatment with three doses of ANS decreased blood lymphocytes, monocytes, and neutrophils and induced tumour load.

CONCLUSIONS

Neutrophils play a crucial role in postoperative adhesion and growth of spilled tumour cells after surgical peritoneal trauma. Prevention of peritoneal neutrophil influx reduces local tumour recurrence.