Involvement of matrix metalloproteinases (MMP-3 and MMP-9) in the pathogenesis of irinotecan-induced oral mucositis

Thymus satureioides Coss. combats oral ulcer via inhibition of inflammation, proteolysis, and apoptosis

Oral ulcer is a frequent condition that commonly affects the tongue and in which 75% of the patients experience pain, and 25% report taste changes. The available therapies are not sufficiently effective for rapid and complete healing of tongue ulcers. We previously annotated the metabolites of Thymus satureioides (TS) aerial parts and reported their antioxidant, dermacosmeceutical and hepatoprotective properties. In this study, we performed in silico analysis, by applying network pharmacology and molecular docking, followed by experimental validation of the effect of local application of T. satureioides (TS) gel at two different concentrations on the healing of acetic-acid-induced tongue ulcer in rats. Salvianolic acid A, phloretic acid caffeate, rosmarinic acid, apigenin, and luteolin were the top bioactive ingredients of TS extract. Network pharmacology showed that the most relevant targets of these active constituents were TLR4, COX-2, MMP-9, TNF-α, and Caspase-3. Molecular docking showed that rosmarinic acid and salvianolic acid had a relatively strong binding affinity, compared to the other compounds, toward all the target proteins. Experimental validation in tongue ulcer model in rats and immunohistochemistry experiments showed that application of a gel containing TS extract (5 and 10%) was effective in healing the tongue ulcer via downregulation of COX-2, TNF-α, MMP-9, and Caspase-3. This study suggests that T. satureioides extract could act as a topical treatment for tongue ulcers by combating inflammation, apoptosis, and proteolysis. The possible treatment potential of some constituents including rosmarinic acid and salvianolic acid in oral ulcerations awaits further investigations to confirm their potency.

Probiotics for the Management of Oral Mucositis: An Interpretive Review of Current Evidence

Mucositis is one of the major side effects of anti-cancer therapies. Mucositis may lead to other abnormalities such as depression, infection, and pain, especially in young patients. Although there is no specific treatment for mucositis, several pharmacological and non-pharmacological options are available to prevent its complications. Probiotics have been recently considered as a preferable protocol to lessen the complications of chemotherapy, including mucositis. Probiotics could affect mucositis by anti-inflammatory and anti-bacterial mechanisms as well as augmenting the overall immune system function. These effects may be mediated through anti microbiota activities, regulating cytokine productions, phagocytosis, stimulating IgA releasement, protection of the epithelial shield, and regulation of immune responses. We have reviewed available literature pertaining to the effects of probiotics on oral mucositis in animal and human studies. While animal studies have reported protective effects of probiotics on oral mucositis, the evidence from human studies is not convincing.

Experimental Chemotherapy-Induced Mucositis: A Scoping Review Guiding the Design of Suitable Preclinical Models

Mucositis is a common and most debilitating complication associated with the cytotoxicity of chemotherapy. The condition affects the entire alimentary canal from the mouth to the anus and has a significant clinical and economic impact. Although oral and intestinal mucositis can occur concurrently in the same individual, these conditions are often studied independently using organ-specific models that do not mimic human disease. Hence, the purpose of this scoping review was to provide a comprehensive yet systematic overview of the animal models that are utilised in the study of chemotherapy-induced mucositis. A search of PubMed/MEDLINE and Scopus databases was conducted to identify all relevant studies. Multiple phases of filtering were conducted, including deduplication, title/abstract screening, full-text screening, and data extraction. Studies were reported according to the updated Preferred Reporting Items for Systematic reviews and Meta-Analyses Extension for Scoping Reviews (PRISMA-ScR) guidelines. An inter-rater reliability test was conducted using Cohen's Kappa score. After title, abstract, and full-text screening, 251 articles met the inclusion criteria. Seven articles investigated both chemotherapy-induced intestinal and oral mucositis, 198 articles investigated chemotherapy-induced intestinal mucositis, and 46 studies investigated chemotherapy-induced oral mucositis. Among a total of 205 articles on chemotherapy-induced intestinal mucositis, 103 utilised 5-fluorouracil, 34 irinotecan, 16 platinum-based drugs, 33 methotrexate, and 32 other chemotherapeutic agents. Thirteen articles reported the use of a combination of 5-fluorouracil, irinotecan, platinum-based drugs, or methotrexate to induce intestinal mucositis. Among a total of 53 articles on chemotherapy-induced oral mucositis, 50 utilised 5-fluorouracil, 2 irinotecan, 2 methotrexate, 1 topotecan and 1 with other chemotherapeutic drugs. Three articles used a combination of these drugs to induce oral mucositis. Various animal models such as mice, rats, hamsters, piglets, rabbits, and zebrafish were used. The chemotherapeutic agents were introduced at various dosages via three routes of administration. Animals were mainly mice and rats. Unlike intestinal mucositis, most oral mucositis models combined mechanical or chemical irritation with chemotherapy. In conclusion, this extensive assessment of the literature revealed that there was a large variation among studies that reproduce oral and intestinal mucositis in animals. To assist with the design of a suitable preclinical model of chemotherapy-induced alimentary tract mucositis, animal types, routes of administration, dosages, and types of drugs were reported in this study. Further research is required to define an optimal protocol that improves the translatability of findings to humans.

Compound Kushen injection reduces severity of radiation-induced gastrointestinal mucositis in rats

Mucositis, or damage/injury to mucous membranes of the alimentary, respiratory, or genitourinary tract, is the major side effect associated with anticancer radiotherapies. Because there is no effective treatment for mucositis at present, this is a particular issue as it limits the dose of therapy in cancer patients and significantly affects their quality of life. Gastrointestinal mucositis (GIM) occurs in patients receiving radiotherapies to treat cancers of the stomach, abdomen, and pelvis. It involves inflammation and ulceration of the gastrointestinal (GI) tract causing diarrhea, nausea and vomiting, abdominal pain, and bloating. However, there is currently no effective treatment for this debilitating condition. In this study, we investigated the potential of a type of traditional Chinese medicine (TCM), compound Kushen injection (CKI), as a treatment for GIM. It has previously been shown that major groups of chemical compounds found in CKI have anti-inflammatory effects and are capable of inhibiting the expression of pro-inflammatory cytokines. Intraperitoneal administration of CKI to Sprague Dawley (SD) rats that concurrently received abdominal irradiation over five fractions resulted in reduced severity of GIM symptoms compared to rats administered a vehicle control. Histological examination of the intestinal tissues revealed significantly less damaged villus epithelium in CKI-administered rats that had reduced numbers of apoptotic cells in the crypts. Furthermore, it was also found that CKI treatment led to decreased levels of inflammatory factors including lower levels of interleukin (IL)-1β and IL-6 as well as myeloperoxidase (MPO)-producing cells in the intestinal mucosa. Together, our data indicate a novel effect of CKI to reduce the symptoms of radiation-induced GIM by inhibiting inflammation in the mucosa and apoptosis of epithelial cells.

Emerging approaches of wound healing in experimental models of high-grade oral mucositis induced by anticancer therapy

Clinical guidelines for oral mucositis (OM) still consist in palliative care. Herein, we summarize cellular and molecular mechanisms of OM ulceration in response to chemical therapies in animal models. We discuss evidenced anti-inflammatory and anti-oxidant drugs which have not been ever used for OM, such as synthetic peptides as well as cell therapy with mesenchymal stem cells; amniotic membranes, mucoadhesive polymers loaded with anti-inflammatory agents and natural or synthetic electrospun. These approaches have been promising to allow the production of drug-loaded membranes, scaffolds for cells encapsulation or guided tissue regeneration.

Tissue Damage in Radiation-Induced Oral Mucositis Is Mitigated by IL-17 Receptor Signaling

Oral mucositis (OM) is a treatment-limiting adverse side effect of radiation and chemotherapy. Approximately 80% of patients undergoing radiotherapy (RT) for head and neck cancers (HNC) develop OM, representing a major unmet medical condition. Our understanding of the immunopathogenesis of OM is limited, due in part to the surprising paucity of information regarding healing mechanisms in the oral mucosa. RNAseq of oral tissue in a murine model that closely mimics human OM, showed elevated expression of IL-17 and related immune pathways in response to head and neck irradiation (HNI). Strikingly, mice lacking the IL-17 receptor (IL-17RA) exhibited markedly more severe OM. Restoration of the oral mucosa was compromised in Il17ra-/- mice and components associated with healing, including matrix metalloproteinase 3, 10 and IL-24 were diminished. IL-17 is typically associated with recruitment of neutrophils to mucosal sites following oral infections. Unexpectedly, in OM the absence of IL-17RA resulted in excessive neutrophil recruitment and immunopathology. Instead, neutrophil activation was IL-1R-driven in Il17ra-/- mice. Blockade of IL-1R and depletion of neutrophils lessened the severity of damage in these mice. Overall, we show IL-17 is protective in OM through multiple mechanisms including restoration of the damaged epithelia and control of the neutrophil response. We also present a clinically relevant murine model of human OM to improve mechanistic understanding and develop rational translational therapeutics.

Chemotherapy drugs and inflammatory cytokines enhance matrix metalloproteinases expression by oral mucosa cells

OBJECTIVE

Oral mucositis (OM), the most common side effect of cancer therapy, is associated with pro-inflammatory cytokines and matrix metalloproteinases (MMPs) increased expression. Although there are approaches for OM management, none is infallible, thus, elucidation of molecular events related to OM etiopathogenesis may improve current therapeutic strategies. This study assessed the influence of pro-inflammatory cytokines and chemotherapy drugs on MMPs expression and synthesis by oral mucosa cells.

DESIGN

Human gingival fibroblasts (HGF) were exposed to different concentrations of methotrexate (MTX) and 5-fluorouracil (5-FU); subsequentially, cell viability, nitric oxide and interleukin(IL)-6 production were evaluated to select the concentration of these drugs that could stimulate inflammatory phenotype without cytotoxic effects. Then, HGF and primary gingival keratinocytes (PGK) were subjected to different stimuli: culture medium (negative control), tumor necrosis factor-alpha (TNF-α - positive control), IL-6, IL-8, MTX, and 5-FU for 3, 6, 12, and 24 h. Next, gene expression and synthesis of MMP-2 and MMP-9 by HGF and MMP-3 by PGK were assessed.

RESULTS

At 6 h, MMP-2 synthesis increased 60 % after exposure to TNF-α and MTX, 40 % after IL-6, and 15 % after IL-8. At 12 h, MMP-9 synthesis increased 15 % after exposure to TNF-α, while MMP-3 synthesis increased 30 % after TNF-α, and 10 % after IL-8. TNF-α-treated groups presented increased gene expression of all MMPs evaluated. IL-8 and 5-FU increased MMP-2 and MMP-3 expression, while IL-6 and MTX augmented MMP-2 expression.

CONCLUSIONS

The chemotherapy drugs and cytokines investigated up-regulated MMPs expression by oral mucosa cells, which may lead to OM establishment and severity.

Effect of Doxycycline Microencapsulation on Buccal Films: Stability, Mucoadhesion and In Vitro Drug Release

The aim of this work was to stabilize doxycycline in mucoadhesive buccal films at room temperature (25 °C). Since doxycycline is susceptible to degradation such as oxidation and epimerization, tablets are currently the only formulation that can keep the drug fully stable at room temperature, while liquid formulations are limited to refrigerated conditions (4 °C). In this study, the aim was to make formulations containing subclinical (antibiotic) doxycycline concentration that can act as matrix metalloproteinase inhibitors (MMPI) and can be stored at temperatures such as 25 °C. Here, doxycycline was complexed with excipients using three techniques and entrapped into microparticles that were stored at 4 °C, 25 °C and 40 °C. Effect of addition of precomplexed doxycycline microparticles on films: stability mucoadhesion capacity, tensile strength, swelling index and in vitro release was studied. The complexation efficiency between drug-excipients, microparticles and films was studied using Fourier-transform infrared spectroscopy (FTIR) and differential scanning calorimetry (DSC). Two of the films were found to be stable at 4 °C but the film containing microparticle composed of precomplexed doxycycline with β-cyclodextrin, MgCl₂, sodium thiosulfate, HPMC and Eudragit^® RS 12.5 was found to be stable at 25 °C until 26 weeks. The addition of microparticles to the films was found to reduce the mucoadhesive capacity, peak detachment force, tensile strength and elasticity, but improved the stability at room temperature.

The Effect of Photobiomodulation on Nitrite and Inflammatory Activity in Radiotherapy-Induced Oral Mucositis: A Randomized Clinical Trial

BACKGROUND AND OBJECTIVES

To investigate pro- and anti-inflammatory cytokines and nitrite salivary levels in patients with head and neck cancer receiving photobiomodulation therapy (PBMT) associated with a Preventive Oral Care Program (POCP), for prevention and control of oral mucositis (OM) during radiotherapy (RT) associated or not with chemotherapy protocol.

STUDY DESIGN/MATERIALS AND METHODS

In this randomized double-blinded clinical trial, 48 patients were randomly assigned to two groups: PBMT (n = 25) and Control (n = 23). In the PBMT group, patients were submitted to PBMT associated with the POCP. In the Control group, patients were submitted only to the POCP. Saliva samples were collected in the 1st (baseline), 7th, 14th, 21st, and 30th sessions of RT, and the levels of interleukin-6 (IL-6), IL-8, IL-10, IL-12p70, IL-1β, and tumoral necrosis factor-α (TNF-α) were measured using the cytometric bead array. Nitrite levels were measured by colorimetric method. OM was assessed using the World Health Organization and the National Cancer Institute scales.

RESULTS

Patients in the PBMT group presented less severe OM. PBMT tended to stabilize nitrite concentration levels during the RT regimen. The IL-1β concentration was associated with higher OM scores. PBMT promoted an increase in IL-12p70, TNF-α, and IL-10 concentration.

CONCLUSION

PBMT was effective in the prevention and control of severe OM, and its mechanism of action may be related to a better balance of inflammatory response that may favor injury control. Lasers Surg. Med. © 2020 Wiley Periodicals LLC.

In vivo and in vitro radiotherapy increased dentin enzymatic activity

OBJECTIVES

The present study investigated the effects of in vitro and in-vivo radiotherapy on endogenous enzymatic activity in dentin using gelatin zymography and in-situ zymography.

METHODS

Gelatin zymographic assays were performed on protein extracts obtained from dentin powder of sound non-irradiated (NRT), in vitro irradiated (VTRT) and in vivo irradiated (VIRT) human teeth. Their proteolytic activities were quantified using band densitometric evaluation. For in-situ zymography, dentin specimens from NRT, VIRT and VTRT were covered with fluorescein-conjugated gelatin and examined with confocal laser-scanning microscopy. Fluorescence intensity emitted by the hydrolyzed fluorescein-conjugated gelatin was quantified and statistically analyzed. In-situ zymography data were statistically analyzed using Kruskal-Wallis ANOVA and Dunn's multiple comparison procedures (α = 0.05).

RESULTS

No difference between in vitro and in vivo radiotherapy treatment was found. Both VTRT and VIRT groups showed increase in MMP-9 expression when compared to NRT group. Significant increases (p < 0.05) in gelatinolytic activity (26 % for VTRT; 55 % for VIRT) were observed when compared to the NRT group.

CONCLUSION

Radiotherapy increase endogenous enzymatic activity in non-restored dentin.

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.

Protective Effect of Cashew Gum (Anacardium occidentale L.) on 5-Fluorouracil-Induced Intestinal Mucositis

Intestinal mucositis is a common complication associated with 5-fluorouracil (5-FU), a chemotherapeutic agent used for cancer treatment. Cashew gum (CG) has been reported as a potent anti-inflammatory agent. In the present study, we aimed to evaluate the effect of CG extracted from the exudate of Anacardium occidentale L. on experimental intestinal mucositis induced by 5-FU. Swiss mice were randomly divided into seven groups: Saline, 5-FU, CG 30, CG 60, CG 90, Celecoxib (CLX), and CLX + CG 90 groups. The weight of mice was measured daily. After treatment, the animals were euthanized and segments of the small intestine were collected to evaluate histopathological alterations (morphometric analysis), levels of malondialdehyde (MDA), myeloperoxidase (MPO), and glutathione (GSH), and immunohistochemical analysis of interleukin 1 beta (IL-1β) and cyclooxygenase-2 (COX-2). 5-FU induced intense weight loss and reduction in villus height compared to the saline group. CG 90 prevented 5-FU-induced histopathological changes and decreased oxidative stress through decrease of MDA levels and increase of GSH concentration. CG attenuated inflammatory process by decreasing MPO activity, intestinal mastocytosis, and COX-2 expression. Our findings suggest that CG at a concentration of 90 mg/kg reverses the effects of 5-FU-induced intestinal mucositis.

Role of oral flora in chemotherapy-induced oral mucositis in vivo

OBJECTIVE

To determine if commensal oral microflora impacts the severity of chemotherapy-induced oral mucositis (OM).

DESIGN

Specific-pathogen-free (SPF) and germ-free Swiss Webster mice in the experimental groups were dosed with 5-fluorouracil (5-FU) to induce OM. Mice in the control group received phosphate buffered saline. Comparative analyses of the epithelial thickness and cell proliferation/turnover rates, as well as the expression levels of metalloproteinases and pro-inflammatory mediators in the oral mucosa between the control and experimental groups were determined by histopathological and immunohistochemical analyses.

RESULTS

5-FU-treated SPF and germ-free mice showed characteristic features of OM with reduced oral epithelial thickness, presence of inflammatory cells in the connective tissues, and increased levels of expression of metalloproteinases and pro-inflammatory cytokines compared to the respective control groups. When 5-FU-treated SPF and germ-free mice were compared, 5-FU-treated germ-free mice exhibited less severe epithelial destruction with higher expression of the cell proliferation marker Ki67, coupled with lower expression levels of metalloproteinases and pro-inflammatory cytokine in the oral mucosa.

CONCLUSION

This study provides the first histopathological evidence that oral flora has a detrimental effect on chemotherapy-induced OM in vivo.

The Role of BPIFA1 in Upper Airway Microbial Infections and Correlated Diseases

The mucosa is part of the first line of immune defense against pathogen exposure in humans and prevents viral and bacterial infection of the soft palate, lungs, uvula, and nasal cavity that comprise the ear-nose-throat (ENT) region. Bactericidal/permeability-increasing fold containing family A, member 1 (BPIFA1) is a secretory protein found in human upper aerodigestive tract mucosa. This innate material is secreted in mucosal fluid or found in submucosal tissue in the human soft palate, lung, uvula, and nasal cavity. BPIFA1 is a critical component of the innate immune response that prevents upper airway diseases. This review will provide a brief introduction of the roles of BPIFA1 in the upper airway (with a focus on the nasal cavity, sinus, and middle ear), specifically its history, identification, distribution in various human tissues, function, and diagnostic value in various upper airway infectious diseases.

Telmisartan Modulates the Oral Mucositis Induced by 5-Fluorouracil in Hamsters

Oral mucositis (OM) is a common adverse effect resulting from cancer therapy. The OM it has implications that may compromise oncologic treatment and decrease the patient's quality of life. The therapeutic options to prevent or treat the symptoms of OM are scarce; there is no effective therapy that improves the symptoms. Based on the need for further research for the treatment of OM, the present study objective was to evaluate the effect of telmisartan (TELM) on the OM induced by 5-fluorouracil (5-FU), using as animal model Golden Syrian hamsters. 5-FU followed by mechanical trauma on day 4 was used to induce OM in hamsters. Euthanasia occurred on the day 10. The experiments were constituted by the groups saline, mechanical trauma, 5-FU, and TELM in three doses (1, 5, or 10 mg/kg). Macroscopic, histopathological, and immunohistochemical analyses as well as immunofluorescence experiments were performed on the oral mucosa of the animals. The samples also were used for analysis enzyme-linked immunosorbent assays and quantitative real-time polymerase chain reactions (qPCR). TELM (5 or 10 mg/kg) was able to reduce the inflammatory ulceration and infiltration in the oral mucosa of the animals, decreasing the levels of the cytokines TNF-α and IL-1β. These treatments was minimize the immunostaining for cyclooxygenase-2, matrix metalloproteinase-9, transforming growth factor-β, and smad 2/3. The nuclear transcription factor kappa B (NFκB) p65 and inducible nitric oxide synthase were reduced in the oral mucosa. Finally, TELM (10 mg/kg) increased the PPARγ gene expression and reduced STAT1 and NFκB p65 gene expression relative to the 5-FU group. Therefore, TELM prevents the OM produced by 5-FU on animal model.

Effects of Matricaria Recutita (L.) in the Treatment of Oral Mucositis

Objective

The objective of this study was to review the effects of the Matricaria recutita (L.) in the treatment of oral mucositis.

Methodology

The online search was performed in the period from June 2016 to April 2018 by means of databases LILACS (Latin American and Caribbean Center on Health Sciences Information), SciELO (Scientific Electronic Library Online), and MEDLINE (Medical Literature Analysis and Retrieval System Online). The consultation was restricted to the years 1991 to 2018 with the aim of elucidating the effects of Matricaria recutita in the treatment of oral mucositis.

Results

The final sample consisted of 21 studies, of which 10 were developed in animals and 11 in humans, published from 1991 to 2017, with a total sample of 644 patients. The total number of patients treated with Matricaria included in 11 studies was 364, while in the control groups the total number was 280. In experimental studies, animal models used were rats and the sample size ranged between 36 and 105 animals submitted to the induction of oral mucositis, where 4 studies used an intraperitoneal injection of 5-fluorouracil, while 7 induced lesion in the mucosa. From the data collected, it should be noted that both studies with humans and with animals showed significant effects. In this way, there is strong evidence for the discussion on the therapy; however, it should be noted that more studies are developed in order to clarify the most appropriate protocol for the prevention and treatment of injuries.

Conclusion

According to the results found in this study, Matricaria recutita appeared to be a promising alternative for the treatment of oral mucositis. However, due to the great variability in the various types of intervention, more controlled double-blind randomized clinical studies are necessary to ensure the best protocol for treating oral mucositis.

Animal models of chemotherapy-induced mucositis: translational relevance and challenges

Chemotherapy for cancer patients induces damaging tissue reactions along the epithelium of the gastrointestinal tract (GIT). This chemotherapy-induced mucositis (CIM) is a serious side effect of cytotoxic drugs, and several animal models of CIM have been developed, mainly in rodents and piglets, to help understand the progression of CIM and how to prevent it. Animal models allow highly controlled experimental conditions, detailed organ (e.g., GIT) insights, standardized, clinically relevant treatment regimens, and discovery of new biomarkers. Still, surprisingly few results from animal models have been translated into clinical CIM management and treatments. The results obtained from specific animal models can be difficult to translate to the diverse range of CIM manifestations in patients, which vary according to the antineoplastic drugs, dose, underlying (cancer) disease, and patient characteristics (e.g., age, genetics, and body constitution). Another factor that hinders the direct use of results from animals is inadequate collaboration between basic science and clinical science in relation to CIM. Here, we briefly describe CIM pathophysiology, particularly the basic knowledge that has been obtained from CIM animal models. These model studies have indicated potential new preventive and ameliorating interventions, including supplementation with natural bioactive diets (e.g., milk fractions, colostrum, and plant extracts), nutrients (e.g., polyunsaturated fatty acids, short-chain fatty acids, and glutamine), and growth factor peptides (e.g., transforming growth factor and glucagon-like peptide-2), as well as manipulations of the gut microbiota (e.g., prebiotics, probiotics, and antibiotics). Rodent CIM models allow well-controlled, in-depth studies of animals with or without tumors while pig models more easily make clinically relevant treatment regimens possible. In synergy, animal models of CIM provide the basic physiological understanding and the new ideas for treatment that are required to make competent decisions in clinical practice.

Phase II investigational oral drugs for the treatment of radio/chemotherapy induced oral mucositis

INTRODUCTION

Oral mucositis is a significant unmet clinical need for many cancer patients. The biological complexity of mucositis' pathogenesis provides a number of mechanistic targets suitable as pharmacologic targets. The diversity of targets has stimulated drug development in search of an effective intervention. In this paper, we review a range of agents that are currently being evaluated.

AREAS COVERED

Drugs for management of oral mucositis vary in formulation, route of administration and biological target. Most propose to interrupt the initiation of injury by suppressing activation of the innate immune response or countering oxidative stress, or minimizing downstream inflammatory responses. Overwhelmingly, the population most studied is patients being treated with concomitant chemoradiation for cancers of the head and neck as this is the cohort that most consistently suffers severe mucositis for long periods of time. The Phase 2 pipeline is robust. Preliminary data reported for a number of agents is optimistic. Genomics may be important in interpreting and comparing responses to agents across widely demographically diverse populations.

EXPERT OPINION

Oral mucositis remains a significant toxicity for patients undergoing cancer treatment. Incremental reports of successes have been noted for a number of targeted agents.

The effect of a single injection of irinotecan on the development of enamel in the Wistar rats

Cancer is the second most frequent cause of death in children. Because the prognosis for childhood malignancies has improved, attention has now focused on long-term consequences of cancer treatment. The immediate effects of chemotherapy on soft tissues have been well described; however, there is less information about long-term effects of chemotherapy on the development of dental tissues. To test the association between the effect of chemotherapy on enamel development, we examined two groups of rats: one that had received an intraperitoneal dose of 200 mg/kg of irinotecan, whereas the other (control) group had received vehicle only. Rats were killed at 6, 48 and 96 hr post-injection; the mandibles dissected out, fixed for histological evaluation and scanned for mineralization defects by Micro-CT. Our results showed structural changes in the ameloblast layer along with a significant reduction in mineralization and thickness of enamel at 96 hr after chemotherapy. These data demonstrate that irinotecan induces structural changes in forming enamel that become apparent after anticancer chemotherapy treatment.

Double-blind placebo-controlled randomized clinical trial evaluating doxycycline effects on chemotherapy-induced oral mucositis

WHAT IS KNOWN AND OBJECTIVE

Chemotherapy (CT)-associated oral mucositis (OM) is one of the most debilitating and painful side effects in oncology patients, with limited effective management options. During CT, matrix metalloproteinases (MMPs) are upregulated, causing damage in mucosal and submucosal tissues, and playing a key role in OM; therefore, the use of subantimicrobial doxycycline as a MMP inhibitor may represent a potential approach for OM management. The aim of this clinical trial was to evaluate the efficacy and safety of low doses of doxycycline in OM development in individuals with acute leukaemia (AL) during CT.

METHODS

Randomized controlled clinical trial (Registration No. NCT01087476) performed in adult AL patients scheduled to receive CT (September 2010-October 2014). Individuals were stratified by leukaemia type and assigned randomly to receive doxycycline hyclate (50 mg/d) (doxycycline group: DG) or placebo (placebo group: PG) before and during CT. Included subjects had a baseline oral examination and thereafter 3 times a week during 21 days. The primary outcome was OM development.

RESULTS AND DISCUSSION

One hundred and forty-seven AL subjects were enrolled: 74 in DG and 73 in PG; baseline characteristics between groups were comparable. During follow-up, 15 (10.2%) individuals developed OM; no differences between treatment groups were found (DG:8.1%, PG:12.3%; P = .59). The mean OM Assessment Scale score was 2.51, without differences between groups (DG:2.7, PG:2.4; P = .65). Low baseline blood albumin levels in the OM-affected individuals were identified, revealing the effect of systemic deterioration as a predisposing factor for OM development. No adverse effects were observed.

WHAT IS NEW AND CONCLUSION

Subantimicrobial doses of doxycycline did not reduce the incidence, onset, duration or severity of OM.

Oral verrucous carcinoma: From multifactorial etiology to diverse treatment regimens (Review)

Oral verrucous carcinoma (OVC) is a verrucous variant of oral squamous cell carcinoma (OSCC), which accounts for 2-12% of all oral carcinomas with a 5-year survival rate of only approximately 50%. Enormous effort has been dedicated to this cancer, and the past decades have witnessed significant advances in relevant diagnostic and therapeutic approaches. Currently, there exist three challenges from primary sub-fields of research and clinical practice of the cancer, namely multifactorial etiology, complex molecular mechanism, and deficient treatment. This study reviews the existing literature on the cancer, encompassing its etiology, clinical manifestations and pathology, molecular mechanism, diagnosis and differential diagnosis, and treatment. For improved treatment of OVC, multifactorial etiology analysis, incorporation of effective biomarkers for mechanism illustration, and integration of multidisciplinary modalities are expounded, in an attempt to resolve the challenges and to provide a useful guide for future research in the field.

Chemotherapy Modulates Intestinal Immune Gene Expression Including Surfactant Protein-D and Deleted in Malignant Brain Tumors 1 in Piglets

Background: Information about chemotherapy-induced intestinal gene expression may provide insight into the mechanisms underlying gut toxicity and help identify biomarkers and targets for intervention. Methods: We analyzed jejunal tissue from piglets subjected to two different, clinically relevant chemotherapy regimens: (1) busulfan plus cyclophosphamide (BUCY) and (2) doxorubicin (DOX). Results: Gene expression analysis identified 1,328 differentially expressed genes in the BUCY piglets and 594 in the DOX piglets, compared to controls. Similar changes in expression were found for 137 genes across the BUCY and DOX piglets. Selected genes of potential biological significance with a similar change in expression across the treatments were controlled by real-time polymerase chain reaction. Key innate defense molecules, including surfactant protein-D and deleted in malignant brain tumors 1, were among the upregulated genes for both treatments. Conclusion: In the developing intestine, chemotherapy increases the expression of genes related to innate immune functions involved in surveillance, protection, and homeostasis of mucosal surfaces.

(−)-Epigallocatechin-3-gallate inhibits matrix metalloproteinases in oral ulcers

The overexpression of MMPs results in excessive extracellular matrix degradation and oral ulcer healing delay.