Cell adhesion molecules are altered during irinotecan-induced mucositis: a qualitative histopathological study

Purpose: Chemotherapy-induced mucositis is characterised by damage to mucous membranes throughout the alimentary tract. This study aims to investigate the expression of cell adhesion molecules (CAMs) following treatment with irinotecan. Methods: Dark agouti rats received a single dose of 175 mg/kg irinotecan and sacrificed at various time points after treatment. Picro-sirius red staining indicated an increase in collagen around crypts from 24 h in both small and large intestinal regions and this diminished at the later time points. CAMs E-cadherin, P-selectin, E-selectin and integrin-α1 were examined using immunohistochemistry. Results: E-cadherin was significantly elevated in jejunal crypts at the time of maximal tissue damage (48 h), while it decreased at the healing phase (96 h) in both jejunum and colon. P-selectin expression decreased significantly in the jejunum following irinotecan. Crypt expression of E-selectin was significantly elevated in the healing phase of mucositis (96 h). Integrin-α1 expression was significantly altered during the time course in the villus (p = 0.0032) and lamina propria (p = 0.039). Conclusions: Irinotecan induced a significant alteration in CAM expression in the jejunum and colon. Changes in adhesion molecule expression may have a direct impact on the loss of mucosal layer integrity seen in mucositis.