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

Restore intestinal steady-state: new advances in the clinical management of chemotherapy-associated diarrhea and constipation

Chemotherapy remains the primary therapeutic strategy for most tumors, particularly those at advanced stages with distant metastases and resistance to molecularly targeted therapy or immunotherapy. There are many manifestations of chemotherapy-induced gastrointestinal toxicity (CIGT), including chemotherapy-induced diarrhea (CID) and chemotherapy-induced constipation (CIC). Although the World Health Organisation and the International Association Against Cancer have different grading criteria and strategies for the prevention and treatment of CIGT, there are still many unanswered questions that need to be clarified. This review critically describes pathological mechanisms and clinical research, analyzing the variability in diagnostic criteria and the absence of standardization in grading severity. We identify a critical gap in understanding the molecular underpinnings of CID and CIC and suggest targeted areas for future research, including developing personalized treatment approaches based on genetic profiling. The findings suggest a comprehensive treatment approach combining pharmacological and non-pharmacological strategies to enhance life quality and treatment adherence. This review will offer a comprehensive bird-eye of pathophysiological mechanisms, clinical manifestations, and therapeutic strategies of CIGT, thereby enriching accessible references to clinicians, and helping them to prevent and control CID and CIC.

Mouse organoids as an in vitro tool to study the in vivo intestinal response to cytotoxicants

Cross-species comparison of drug responses at the organoid level could help to determine the human relevance of findings from animal studies. To this end, we first need to evaluate the in vitro to in vivo translatability of preclinical organoids. Here, we used 5-fluorouracil (5-FU) as an exemplar drug to test whether the in vivo gut response to this cytotoxicant was preserved in murine intestinal organoids. Mice treated with 5-FU at 20 or 50 mg/kg IV (low and high dose, respectively) displayed diarrhea at clinically relevant exposures. 5-FU also induced intestinal lesions, increased epithelial apoptosis, and decreased proliferation in a dose-dependent manner. To enable comparison between the in vitro and in vivo response, top nominal in vitro drug concentrations that caused significant cytotoxicity were chosen (dose range 1-1000 µM). The inferred intracellular concentration in organoids at 1000 µM was within the tissue exposure range related to intestinal toxicity in vivo. 5-FU at ≥ 100 µM decreased ATP levels and increased Caspase-3 activity in intestinal organoids. In keeping with the in vivo findings, 5-FU increased the percentage of Caspase-3-positive cells and reduced Ki67 staining. At the transcriptome level, there was an overlap in the activity of pathways related to 5-FU's mode of action, lipid and cholesterol metabolism and integrin signaling across in vivo gut and organoids. The predicted activity state of upstream regulators was generally well preserved between setups. Collectively, our results suggest that despite their inherent limitations, organoids represent an adequate tool to explore the intestinal response to cytotoxicants.

Bioactive Polyphenols from Pomegranate Juice Reduce 5-Fluorouracil-Induced Intestinal Mucositis in Intestinal Epithelial Cells

Intestinal epithelial cells (IECs) play a pivotal role in maintaining intestinal homeostasis. Different noxious agents, among them also anticancer therapies, can impair intestinal epithelial integrity triggering inflammation and oxidative stress. A frequent complication of chemotherapy is gastrointestinal mucositis, strongly influencing the effectiveness of therapy, increasing healthcare costs, and impairing patients’ quality of life. Different strategies are used to treat gastrointestinal mucositis, including products from natural sources. Our study focused on the effect of pomegranate (Punica granatum L.) juice extract on IEC-6 cells, both during inflammatory conditions and following treatment with 5-fluorouracil (5-FU). The polyphenolic profile of pomegranate juice was characterized in detail by Online Comprehensive two dimensional Liquid Chromatography-Mass Spectrometry. The evaluation of pomegranate juice extract in IEC-6 indicates a significant inhibition in proinflammatory factors, such as cytokines release, cyclooxygenase-2 and inducible nitric oxide synthase expression, and nitrotyrosine formation. Pomegranate also inhibited oxidative stress and adhesion protein expression. In 5-FU-treated IEC-6, pomegranate also inhibited both inflammatory and oxidative stress parameters and apoptosis. It promoted wound repair and tight junction expression. These results suggest a potential use of pomegranate as an adjuvant in the treatment of intestinal inflammatory and oxidative stress states, which also occur during chemotherapy-induced mucositis.

Animal models of mucositis: critical tools for advancing pathobiological understanding and identifying therapeutic targets

PURPOSE OF REVIEW

Mucositis remains a prevalent, yet poorly managed side effect of anticancer therapies. Mucositis affecting both the oral cavity and gastrointestinal tract predispose to infection and require extensive supportive management, contributing to the growing economic burden associated with cancer care. Animal models remain a critical aspect of mucositis research, providing novel insights into its pathogenesis and revealing therapeutic targets. The current review aims to provide a comprehensive overview of the current animal models used in mucositis research.

RECENT FINDINGS

A wide variety of animal models of mucositis exist highlighting the highly heterogenous landscape of supportive oncology and the unique cytotoxic mechanisms of different anticancer agents. Golden Syrian hamsters remain the gold-standard species for investigation of oral mucositis induced by single dose and fractionated radiation as well as chemoradiation. There is no universally accepted gold-standard model for the study of gastrointestinal mucositis, with rats, mice, pigs and dogs all offering unique perspectives on its pathobiology.

SUMMARY

Animal models are a critical aspect of mucositis research, providing unprecedent insight into the pathobiology of mucositis. Introduction of tumour-bearing models, cyclic dosing scheduled, concomitant agents and genetically modified animals have been integral in refining our understanding of mucositis.

Gliclazide Prevents 5-FU-Induced Oral Mucositis by Reducing Oxidative Stress, Inflammation, and P-Selectin Adhesion Molecules

Oral mucositis (OM) is one of the main side effects of the head and neck cancer treatment, particularly radiotherapy and/or chemotherapy. OM is characterized by ulcers, erythema, dysphagia, xerostomia, and increased susceptibility to opportunistic infections. In the perspective of finding pharmacological therapies to prevent inflammation and ulceration of OM, the investigation of the pleiotropic effect of commercial drugs is needed, among them gliclazide, an antidiabetic drug. This study aimed to evaluate the effect of gliclazide in an experimental OM model induced by 5-fluorouracil. Male hamsters were pre-treated with oral gliclazide (1, 5, or 10 mg/kg) for 10 days. Cheek pouch samples were subjected to histopathological and immunohistochemical analysis (COX₂, iNOS, MMP-2, NFκB P65, GPx) and imunofluorescence (P-selectin). IL-1β and TNF-α levels, Myeloperoxidase activity (MPO) and malondialdehyde (MDA) levels were investigated by ultraviolet-visible spectroscopy analysis. NFκB NLS P50 protein levels were analyzed by western blotting. The group treated with gliclazide at a dose of 10 mg/kg showed presence of erythema, no evidence of erosion, and absence of mucosal ulceration with a score of 1 (1–2) (p < 0.01). Histopathological data for the group treated with gliclazide 10 mg/kg showed re-epithelialization, discrete mononuclear inflammatory infiltrate and absence of hemorrhage, edema, ulcers and abscesses with a score of 1 (1–1) (p < 0.01). Treatment with gliclazide 10 mg/kg reduced MPO activity (p < 0.001), MDA levels (p < 0.001) and NFκB NLS P50 (p < 0.05) protein levels, resulting in low immunostaining to Cox-2, iNOS (p < 0.05), NFκB P65 (p < 0.05), and negative immunoreaction to MMP-2 (p < 0.001). However, it appeared that for Gpx1, the staining was restored in the GLI 10-FUT group compared with 5FUT/saline (p < 0.05). Immunofluorescence revealed decreased levels of P-selectin (p < 0.001) after treatment with gliclazide 10 mg/kg (p < 0.05). In summary, gliclazide accelerated mucosal recovery and reduced oxidative stress and inflammation in the 5-FU-induced OM in hamsters.