Induction of Proteases in Peritoneal Carcinomatosis, the Role of ICAM-1/CD43 Interaction

Abstract

Introduction: The development of peritoneal metastases is a significant clinical issue in the treatment of abdominal cancers and is associated with poor prognosis. We have previously shown that ICAM-1-CD43 interaction plays a significant role in tumor adhesion. However, an invasive phenotype is critical to establish tumor progression via cell associated and secreted proteases including matrix metalloproteinases. High metalloproteinases level significantly enhanced metastasis phenotype on tumors, a detrimental effect on surgical outcome. We investigated the role of direct and indirect signaling between the mesothelium and the tumor cells in enhancing tumor invasion and possible therapeutic intervention.

Methods: Mesothelial cells were enzymatically derived from human omental tissue and implanted in 24 wells plates. Colorectal cancer cells were then introduced and allowed a direct and an indirect contact with the mesothelial layer. Anti-ICAM antibodies, anti-CD43 antibodies, and heparin were used to block MMP production. Gelatin zymography was performed on the supernatant to detect MMPs activity.

Results: MMP production was observed in mesothelial and tumor cells. Direct contact between cell types enhanced MMP9 and 2 (p < 0.05). Indirect contact also stimulate MMPs but at a lower degree. ICAM-1 blocking antibodies attenuated MMP production in direct contact to that observed in the indirect. Heparin introduction achieved a similar outcome.

Conclusions: ICAM-1-CD43 interaction plays a vital role in tumor cells-peritoneum adhesion and invasion, which is manifested by the increased production of MMPs leading to tumor invasion and peritoneal loco-regional. Blocking this interaction with heparin can provide a new therapeutic option.

Keywords: CD43; Colorectal cancer; Heparin; ICAM-1; MMP-2 and MMP-9; Mesothelial cells.

Figure 1

Mesothelial and Tumor cells MMP expression. (a) Characteristic gelatin zymography indicating both mesothelial and colorectal tumor cells expression MMP2 and MMP9. Proteases activity is higher in the mesothelial cells. Each line indicates one of triplicate taken from either SW1222 or primary mesothelial cells. (b) Graph shows the results of minimum three experiments.

Figure 2

Mesothelial-Tumor cells interactions up-regulate MMP expression. (a) Representative gelatin zymography shows total MMP-2 and 9 productions by mesothelial cells (A) and tumor Cells (B). Mesothelial cells in direct contact with tumor cells (C) and in. indirect contact with tumor cells (D). There is clear up-regulation of MMPs expression when the mesothelial cells were co-cultured with tumor cells. MMPs expression by tumor cells alone in negligible. (b) Graph indicating the results of minimum three experiment (Meso + FT = Mesothelial cell + Filter + Tumor cells. Meso + T = Mesothelial cells + Tumor cells).

Figure 3

Blocking cell adhesion molecules decreases proteases expression. (a) Representative gelatin zymography shows MMP-2 and 9 expressions by mesothelial cells (A) and tumor cells (B). This expression was up-regulated when both mesothelial and tumor cells co-cultured together (C). However, the introduction of anti-ICAM (D) and anti-CD43 (E) antibodies blocked this interaction. (b) Graph shows the results of minimum three experiments.

Figure 4

Heparin reduces proteases production. (a) Representative gelatin zymography shows MMP-2 and 9 expressions by mesothelial cells (A) and tumor cells (D). Heparin down-regulate MMP-2 and 9 activities when it was introduced (B) in comparison to the standard co-culture (C). (b) Graph indicating the results of minimum three experiments.