The pathobiology of mucositis

Risk factors for oral mucositis in children receiving hematopoietic cell transplantation for primary immunodeficiencies: a retrospective study

OM is a frequent complication for patients undergoing HSCT. The aim of this study was to evaluate the possible risk factors for OM in children undergoing HSCT for PI. A retrospective study was carried out on 55 consecutive medical records of patients with PI (including osteopetrosis) who underwent HSCT. Age at the time of HSCT, gender, diagnosis, type of donor, conditioning regimen, engraftment, graft-versus-host disease, and severity and duration of OM were collected at the beginning of the conditioning until day 100 post-HSCT or death. OM was measured using the WHO scale. Patients' age range at the time of HSCT was quite wide; 59.2% of the patients who were under nine months (n = 13) developed OM vs. 87.8% of the patients older than nine months (n = 29) (p = 0.01). T-cell positive patients had a statistically significant higher risk of developing OM (p = 0.04), as did those receiving a more intensive conditioning regimen (p < 0.01). PI patients undergoing HSCT are at higher risk of developing OM if the PI is a T-lymphocyte-positive disease and/or if the HSCT recipient is over nine months of age.

Emerging evidence on the pathobiology of mucositis

BACKGROUND

Considerable progress has been made in our understanding of the biological basis for cancer therapy-induced mucosal barrier injury (mucositis). The last formal review of the subject by MASCC/ISOO was published in 2007; consequently, an update is timely.

METHODS

Panel members reviewed the biomedical literature on mucositis pathobiology published between January 2005 and December 2011.

RESULTS

Recent research has provided data on the contribution of tissue structure changes, inflammation and microbiome changes to the development of mucositis. Additional research has focused on targeted therapy-induced toxicity, toxicity clustering and the investigation of genetic polymorphisms in toxicity prediction. This review paper summarizes the recent evidence on these aspects of mucositis pathobiology.

CONCLUSION

The ultimate goal of mucositis researchers is to identify the most appropriate targets for therapeutic interventions and to be able to predict toxicity risk and personalize interventions to genetically suitable patients. Continuing research efforts are needed to further our understanding of mucositis pathobiology and the pharmacogenomics of toxicity.

Oral bacterial community dynamics in paediatric patients with malignancies in relation to chemotherapy-related oral mucositis: a prospective study

The role of oral bacteria in the development of chemotherapy-related oral mucositis has not been fully elucidated. This study aimed to investigate oral bacterial community diversity and dynamics in paediatric patients with malignancies in relation to the occurrence of oral mucositis. Patients with malignancies (n = 37) and reference individuals without known systemic disorders (n = 38) were recruited. For patients, oral bacterial samples were taken from mucosal surfaces both at the time of malignancy diagnosis and during chemotherapy. If oral mucositis occurred, samples were taken from the surface of the mucositis lesions. Oral mucosal bacterial samples were also taken from reference individuals. All samples were assessed using a 16S ribosomal RNA gene 454 pyrosequencing method. A lower microbial diversity (p < 0.01) and a higher intersubject variability (p < 0.001) were found in patients as compared with reference individuals. At the time of malignancy diagnosis (i.e. before chemotherapy) patients that later developed mucositis showed a higher microbial diversity (p < 0.05) and a higher intersubject variability (p < 0.001) compared with those without mucositis. The change of bacterial composition during chemotherapy was more pronounced in patients who later developed mucositis than those without mucositis (p < 0.01). In conclusion, we found a higher microbial diversity at the time of malignancy diagnosis in patients who later develop oral mucositis and that these patients had a more significant modification of the bacterial community by chemotherapy before the occurrence of mucositis. These findings may possibly be of clinical importance in developing better strategies for personalized preventive management.

Biomarkers of chemotherapy-induced diarrhoea: a clinical study of intestinal microbiome alterations, inflammation and circulating matrix metalloproteinases

PURPOSE

A common side effect of chemotherapy treatment is diarrhoea. Unfortunately, the underlying mechanisms of chemotherapy-induced diarrhoea (CD) are poorly understood. We aimed to determine if faecal microbes of CD patients were displaced, if faecal calprotectin increased during CD and if there were alterations in circulating matrix metalloproteinases, nuclear factor kappa B (NF-κB), IL-1β and TNF.

PATIENTS AND METHODS

Twenty-six cancer patients receiving chemotherapy were enrolled and requested to provide stool samples and blood samples at various times during their chemotherapy cycle. Stool samples were analysed using conventional culture techniques and qRT-PCR. ELISA kits determined faecal calprotectin levels, levels of circulating matrix metalloproteinases and circulating NF-κB, IL-1β and TNF.

RESULTS

The majority of patients with CD showed decreases in Lactobacillus spp., Bifidobacterium spp., Bacteroides spp. and Enterococcus spp. Increases were observed in Escherichia coli and Staphylococcus spp. Methanogenic archaea were also quantified, with all patients except one showing a decrease. Faecal calprotectin levels were increased in 81.25 % of patients with CD. Circulating MMP-3 and MMP-9 significantly increased following chemotherapy. Circulating levels of NF-κB, IL-1β and TNF were increased following chemotherapy, although this did not reach significance.

CONCLUSIONS

We demonstrated that CD is associated with marked changes in intestinal microflora, methanogenic archaea, matrix metalloproteinase and serum levels of NF-κB, IL-1β and TNF. These changes may result in diminished bacterial functions within the gut, altering gut function and initiating intestinal damage, resulting in the onset of diarrhoea. More importantly, these changes may provide clinicians with a possible new target for biomarkers of toxicity.

Status of oral ulcerative mucositis and biomarkers to monitor posttraumatic stress disorder effects in breast cancer patients

BACKGROUND

This study was designed to assess oral ulcerative mucositis, C-reactive protein, blood pressure, heart rate and thyroid function in breast cancer patients in relation to the occurrence of posttraumatic stress disorder 
(PTSD).

METHODS

A total of 120 female breast cancer patients and women 100 healthy subjects were enrolled in this study. PTSD status was assessed by questionnaire. Before and after treatment (modified radical mastectomy and chemotherapy), serum samples were collected and measured for levels of triiodothyronine (T3), thyroxine (T4), thyroid stimulating hormone (TSH) and high-sensitivity C-reactive protein (hs-CRP) by ELISA. Oral ulcerative mucositis was evaluated by the number and duration of oral ulcers and the degree of pain.

RESULTS

Breast cancer patients experienced long-term PTSD and had elevated serum T3 and T4 levels. Patients experienced more severe pain and longer duration of oral ulcers compared with the healthy group. Oral ulcers were significantly associated with PTSD score in terms of the number of ulcers (p=0.0025), the degree of pain (p<0.0001) and the duration of ulcers (p<0.0001).

CONCLUSION

These findings support that thyroid function is altered in breast cancer patients with PTSD. Elevation of T3 and T4 and oral ulcerative mucositis might be indicative of the emotional status of breast cancer patients.

Tissue-engineered oral mucosa to study radiotherapy-induced oral mucositis

PURPOSE

Oral mucositis is a severe and often dose-limiting side-effect of cancer therapy that occurs in patients receiving radiotherapy for head and neck cancers. Although radiation-induced effects on keratinocytes have been studied, little is known about its effect on fibroblasts or endothelial cells or, more importantly, when all these cells are combined in an engineered oral mucosal model.

MATERIALS AND METHODS

Monolayer cultures of normal oral keratinocytes, normal oral fibroblasts, human dermal microvascular endothelial cells or tissue-engineered oral mucosa (TEOM) were exposed to 20 Gy irradiation. Cell damage and cytokine release was measured for 72 h for monolayer cultures and for up to 21 d for TEOM.

RESULTS

Compared to non-irradiated cells, the viability of all monolayer and co-cultures was significantly reduced 72 h post-irradiation while levels of secreted interleukin IL-6 and CXCL8 were increased. The viability of irradiated TEOM models was significantly reduced compared to controls at all time-points. Histologically, irradiated TEOM displayed thinner epithelium, increased apoptosis and more extensive damage than non-irradiated models. IL-6, CXCL8 and granulocyte macrophage colony-stimulating factor release was reduced whereas IL-1α levels were increased in irradiated TEOM models compared to controls.

CONCLUSIONS

TEOM models comprising of mixed cell populations may prove useful in examining the pathobiology of radiation-induced mucositis.

The multifunctional alarmin HMGB1 with roles in the pathophysiology of sepsis and cancer

Although originally described as a highly conserved nuclear protein involved in DNA replication, transcription and repair, high-mobility group box-1 protein (HMGB1) has emerged as a key mediator in the regulation of immune responses to infection and sterile injury by exhibiting all the properties of a prototypic 'alarmin'. These include rapid passive release in response to pathogenic infection and/or traumatic injury, active secretion providing for chemotactic and cytokine-like function and an ability to resolve inflammation, including tissue repair and remodelling. In this review, we will give an overview of the post-translational modifications necessary for such diversity in biological activity, concentrating particularly on how differences in oxidation of highly conserved redox-sensitive cysteine residues can potentiate inflammatory responses and dictate cellular fate. We will also review the most recent literature on HMGB1 and its involvement in the pathophysiology of sepsis and cancer, as well as cancer therapy-induced mucositis.

Pretherapeutic plasma pro- and anti- inflammatory mediators are related to high risk of oral mucositis in pediatric patients with acute leukemia: a prospective cohort study

Objective

This prospective study evaluated clinical risk indicators as well as pro- and anti- inflammatory mediators at the time of malignancy diagnosis in relation to chemotherapy-related oral mucositis in pediatric population.

Methods

Patients (n = 104) under 18 years of age with primary malignancies and undergoing chemotherapy were included. Potential risk indicators were analyzed using binary logistic regression with oral mucositis as the outcome. In a subgroup (n = 35), plasma samples at the time of malignancy diagnosis were analyzed for inflammatory cytokines and an antimicrobial protein pro-LL-37 (hCAP18).

Results

In the multivariable model, type of malignancy diagnosis was significantly associated with oral mucositis, with highest risk of oral mucositis in patients with acute leukemia compared to those with lymphoma or solid tumors. At the time of malignancy diagnosis, plasma from patients with acute leukemia displayed higher concentrations (P<0.05) of IL-6, IL-8, IL-10, and TNF-α and lower levels of pro-LL-37 (P<0.001).

Conclusions

The results imply that pretherapeutic high levels of inflammatory cytokines and low levels of pro-LL-37 in plasma might contribute to the high incidence of oral mucositis in patients with acute leukemia. These findings may add to our understanding of the predispositions to oral mucositis in children with malignancies.

Experimental simulation of radio- and chemoradio stomatitis in rats

Experimental models of stomatitis developing in response to an isolated (radiation) and combined (radiation and chemical) exposure of experimental animals, were created. The severity of radiation-induced stomatitis was determined by the dose of radiation exposure. Additional exposure to a chemical factor (cyclophosphamide) augmented the destructive effect of ionizing radiation on the buccal mucosa of rats.

Chemotherapy-induced mucositis: the role of the gastrointestinal microbiome and toll-like receptors

Alimentary mucositis is a major clinical problem. Patients with mucositis are at significantly increased risk of infection and are often hospitalized for prolonged periods. More importantly, these patients often have to undergo reductions in their cytotoxic therapy, which may lead to reduced survival. Unfortunately, there are very limited therapeutic options for mucositis and no effective prevention. The human gut microbiome is receiving increased attention as a key player in the pathogenesis of alimentary mucositis with recent literature suggesting that changes in bacteria lead to mucositis. The bacteria which are found throughout the gut are tightly regulated by the toll-like receptor (TLR) family which currently has 13 known members. TLRs play a critical role in gut homeostasis and bacterial regulation. Furthermore, TLRs play a critical role in the regulation of nuclear factor kappa B, a key regulator of alimentary mucositis. However to date, no research has clearly identified a link between TLRs and alimentary mucositis. This critical literature review seeks to correct this.

Interaction between host cells and microbes in chemotherapy-induced mucositis

Cancer patients receiving chemotherapy often develop mucositis as a direct result of their treatment. Recently, the intestinal microbiota has attracted significant attention in the investigation of the pathobiology of mucositis, with a number of studies investigating the effects of chemotherapeutic agents on the microbiota. With significant effects on the intestinal microbiota occurring following the administration of chemotherapy, there is now interest surrounding the downstream pathological effects that may be associated with the altered intestinal ecology. This review seeks to identify links between signalling pathways previously demonstrated to have a role in the development of mucositis, and the altered intestinal microbiota.

Emerging evidence on the pathobiology of mucositis

BACKGROUND

Considerable progress has been made in our understanding of the biological basis for cancer therapy-induced mucosal barrier injury (mucositis). The last formal review of the subject by MASCC/ISOO was published in 2007; consequently, an update is timely.

METHODS

Panel members reviewed the biomedical literature on mucositis pathobiology published between January 2005 and December 2011.

RESULTS

Recent research has provided data on the contribution of tissue structure changes, inflammation and microbiome changes to the development of mucositis. Additional research has focused on targeted therapy-induced toxicity, toxicity clustering and the investigation of genetic polymorphisms in toxicity prediction. This review paper summarizes the recent evidence on these aspects of mucositis pathobiology.

CONCLUSION

The ultimate goal of mucositis researchers is to identify the most appropriate targets for therapeutic interventions and to be able to predict toxicity risk and personalize interventions to genetically suitable patients. Continuing research efforts are needed to further our understanding of mucositis pathobiology and the pharmacogenomics of toxicity.

Tissue-engineered mucosa is a suitable model to quantify the acute biological effects of ionizing radiation

The aim of this study was to evaluate the suitability of tissue-engineered mucosa (TEM) as a model for studying the acute effects of ionizing radiation (IR) on the oral mucosa. TEM and native non-keratinizing oral mucosa (NNOM) were exposed to a single dose of 16.5Gy and harvested at 1, 6, 24, 48, and 72h post-irradiation. DNA damage induced by IR was determined using p53 binding protein 1 (53BP1), and DNA repair was determined using Rad51. Various components of the epithelial layer, basement membrane, and underlying connective tissue were analyzed using immunohistochemistry. The expression of cytokines interleukin-1β (IL-1β) and transforming growth factor beta 1 (TGF-β1) was analyzed using an enzyme-linked immunosorbent assay. The expression of DNA damage protein 53BP1 and repair protein Rad51 were increased post-irradiation. The expression of keratin 19, vimentin, collage type IV, desmoglein 3, and integrins α6 and β4 was altered post-irradiation. Proliferation significantly decreased at 24, 48, and 72h post-irradiation in both NNOM and TEM. IR increased the secretion of IL-1β, whereas TGF-β1 secretion was not altered. All observed IR-induced alterations in TEM were also observed in NNOM. Based on the similar response of TEM and NNOM to IR we consider our TEM construct a suitable model to quantify the acute biological effects of IR.

Effect of Renal Function on the Pharmacokinetics of Palifermin

Palifermin (deltaN23KGF) decreases the incidence, severity, and duration of oral mucositis. The objectives of this open-label study were to evaluate the pharmacokinetics of single-dose palifermin in subjects with varying degrees of renal function. A single 90-mcg/kg intravenous dose of palifermin was administered to 31 subjects with varying levels of renal function (normal to requiring hemodialysis). Pharmacokinetic analyses were conducted using serum palifermin concentrations. There was considerable overlap in mean palifermin serum clearance among the groups, ranging from 318 to 495 mL/h/kg, indicating that the level of renal function did not affect clearance in humans; thus, no dose adjustment of palifermin is indicated for patients with renal dysfunction.

Oral mucositis in head and neck cancer: risk, biology, and management

Of the toxicities associated with conventional forms of treatment for head and neck cancers, probably none has such a consistent legacy as oral mucositis.1 Despite the fact that mucosal injury was noted as far back as Marie Curie's first forays into therapeutic radiation, an effective intervention has yet to be developed. In addition to its historic link to radiation, new therapeutic strategies including induction chemotherapy often produce mucositis, and targeted therapies appear to alter mucositis risk and its severity and course.2 The symptomatic effect of oral mucositis is profound. Disabling oral and oropharyngeal pain prevents patients from eating normally, requires opiate analgesics, and in some cases results in alteration or discontinuation of anticancer therapy.3 Furthermore, the health and economic consequences of oral mucositis are far from trivial. The incremental cost of oral mucositis in patients with head and neck cancer exceeds $17,000 (USD).4.

Oral bacteria and yeasts in relationship to oral ulcerations in hematopoietic stem cell transplant recipients

BACKGROUND

Oral mucositis is a serious and debilitating side effect of conditioning regimens for hematopoietic stem cell transplant (HSCT). Through HSCT, the homeostasis in the oral cavity is disrupted. The contribution of the oral microflora to mucositis remains to be clarified. The aim of our study was to investigate the relationship between yeasts, bacteria associated with periodontitis, and oral ulcerations in HSCT recipients.

METHODS

This prospective observational study included 49 adult HSCT recipients. Twice weekly, oral ulcerations were scored, and oral rinsing samples were obtained. Samples were evaluated for the total bacterial load; the Gram-negative bacteria: Aggregatibacter actinomycetemcomitans, Porphyromonas gingivalis, Prevotella intermedia, Parvimonas micra, Fusobacterium nucleatum, Tannerella forsythia, and Treponema denticola; and the yeasts: Candida albicans, Candida glabrata, Candida kefyr, Candida krusei, Candida parapsilosis, and Candida tropicalis using real-time polymerase chain reaction with specific primers and probes. Explanatory variables for oral ulcerations were calculated using the multilevel generalized estimated equations (GEE) technique.

RESULTS

None of the samples was positive for A. actinomycetemcomitans, while F. nucleatum was found most often (66 % of samples). C. albicans was the most isolated yeast (88 % of samples), whereas C. parapsilosis was found in only 8 % of the samples. Multivariate GEE analyses identified P. gingivalis, P. micra, T. denticola, F. nucleatum, C. glabrata, and C. kefyr as significant explanatory variables of oral ulcerations.

CONCLUSIONS

Our data indicate that P. gingivalis in particular, but also P. micra, T. denticola, F. nucleatum, C. glabrata, and C. kefyr may play a role in ulcerative oral mucositis in patients undergoing HSCT.

Bevacizumab-induced oral mucositis in background of cutaneous plaque-type psoriasis

OBJECTIVE

To report the serial development of oral mucositis following infusion of bevacizumab in a young woman with a malignant brain tumor and history of cutaneous psoriasis.

CASE SUMMARY

A 29-year-old woman with a history of active cutaneous psoriasis and a malignant glioneuronal tumor was treated with bevacizumab for 2.5 years. With each infusion of bevacizumab, she developed oral mucositis within 36 hours. She received temozolomide as part of concurrent therapy with radiation and as maintenance therapy; it was discontinued after continuous therapy for 1.5 years. Bevacizumab 10 mg/kg was added after 7 cycles of maintenance temozolomide, as the tumor had minimal response and evidence of increased perfusion with angiogenesis on imaging studies. All medication, including temozolomide, was evaluated and eventually discontinued, with the exception of bevacizumab, which remained the drug suspected of causing the mucositis.

DISCUSSION

Oral mucositis is a frequent adverse effect of cytotoxic chemotherapy, but has not been reported with bevacizumab. The Naranjo probability scale indicated a probable adverse drug reaction. This likely indicates that bevacizumab is one of many drugs known to induce exacerbation of psoriatic disease. We speculate that oral mucositis developed as bevacizumab-induced generation of proinflammatory cytokines within the vascular endothelium, leading to mucosal damage and ulceration. In addition, interruption of reparative angiogenic pathways with bevacizumab likely contributed to the severity of mucositis.

CONCLUSIONS

Clinicians should be aware that bevacizumab can potentially exacerbate psoriatic disease.

Effect of topical chamomile on immunohistochemical levels of IL-1β and TNF-α in 5-fluorouracil-induced oral mucositis in hamsters

PURPOSE

The aim of the present study was to evaluate the effect of topical chamomile and corticosteroid treatment on the profile of tissue cytokines (IL-1β and TNF-α) in 5-fluorouracil-induced oral mucositis in hamsters.

METHODS

Thirty-six hamsters were randomly separated into three groups (12 animals each): Group I--without treatment (control); Group II-treatment with chamomile (Ad-Muc(®)); and Group III--treatment with corticosteroid (betamethasone elixir- Celestone(®)). The animals received an intraperitoneal injection of 5--fluorouracil on Days 0 and 2. On Days 3 and 4, the buccal mucosa was scratched and therapy was initiated on Day 5. Three animals from each group were killed on Days 0, 5, 10, and 14 and the buccal mucosa was removed. The streptavidin-biotin complex method was used to delineate the in situ distribution, localization, and semiquantitative analysis of IL-1β and TNF-α. Data from the semiquantitative analysis of immunohistochemical staining were comparatively analyzed using the Kruskal-Wallis test, followed by Dunn's multiple comparisons test.

RESULTS

The distribution and localization of IL-1β and TNF-α immunolabeling were similar. These proteins exhibited a diffuse pattern distributed throughout the connective tissue. The epithelium and adipose tissue were negative for both proteins. The semiquantitative analysis revealed that immunolabeling of IL-1β and TNF-α increased in all groups with the development of mucositis. On Day 10 (period of peak mucositis), the group treated with chamomile had lower scores for both pro-inflammatory cytokines.

CONCLUSIONS

Treatment with topical chamomile reduced the tissue levels of IL-1β and TNF-α, thereby demonstrating anti-inflammatory action in oral mucositis in hamsters.

An evaluation of Vitamin E and Pycnogenol in children suffering from oral mucositis during cancer chemotherapy

OBJECTIVE

The purpose of the present study was to evaluate and compare the effectiveness of Vitamin E (E) and Pycnogenol (P) in treatment of Chemotherapy-Related Oral Mucositis (ChROM) in children.

MATERIALS AND METHODS

A total of 72 children, aged between 6 and 15 years, with ChROM were selected and randomly divided into three groups after assessment of oral mucositis (OM) by WHO grading system. Glycerine (control), E, and P were topically applied in group I, II, and III, respectively, and the prognosis of OM was assessed by functional, objective, and subjective parameters.

RESULTS

Patients of group II and III showed significant improvement when ChROM was analyzed through scoring systems - WHO grading, Oral Mucositis Assessment Scale (OMAS), and Children's International Mucositis Evaluation Scale (ChIMES) as compared to group I (P < 0.001); however, there was no significant difference between groups II and III.

CONCLUSION

Both the drugs E and P per se are effective for treatment of OM with P being not effective for the treatment of severe mucositis (grade 4). Combination of E and P and additional agents may be tried for better results.

Amelioration of radiation-induced acute inflammation and mucosal atrophy by beta-hydroxy-beta-methylbutyrate, L-glutamıne, and L-argınıne: results of an experimental study

PURPOSE

We aimed to evaluate the effects of β-hydroxy-β-methylbutyrate, L-glutamine, and L-arginine (HMB/Glu/Arg) on radiation-induced acute inflammation and mucosal atrophy in the oral mucosa.

METHODS

Twenty-eight rats were divided into four groups. group (G) 1 was defined as control group, and G2 was the radiation therapy (RT) group. G3 and G4 were HMB/Glu/Arg control and 17 Gy RT plus HMB/Glu/Arg groups, respectively. A single dose of 17 Gy RT was given to the head and neck area, and the active supplement consisting of 5.2 g of HMB, 29.6 g arginine, and 29.6 g of glutamine which was equivalent to 60 kg adult dose was calculated for each rat and administrated orally. HMB/Glu/Arg started from the day of RT and continued until the animals were sacrificed 7 days after the RT. The extent of acute inflammation and mucosal atrophy for each rat was quantified with image analysis of histological sections of the oral mucosa.

RESULTS

There were significant differences in terms of epithelial thickness, subepithelial edema, inflammation, and congestion between all groups (p values were <0.001, 0.003, <0.001, and 0.001 for each parameter, respectively). Using HMB/Glu/Arg alone led to hypertrophic changes in the epithelial layer. Moreover, when used with RT, HMB/Glu/Arg reversed radiation-induced epithelial atrophy (p, 0.006) and decreased radiation-induced inflammation at a significant level (p, 0.007).

CONCLUSION

Concomitant use of HMB/Glu/Arg appears to ameliorate the radiation-induced acute inflammation and mucosal atrophy which represent the early phase of acute oral mucositis; however, this finding should be clarified with further clinical studies.

Systematic review of cytokines and growth factors for the management of oral mucositis in cancer patients

PURPOSE

The aim of this project was to review the literature and define clinical practice guidelines for the use of cytokines and growth factor agents for the prevention or treatment of oral mucositis induced by cancer chemotherapy or radiotherapy.

METHODS

A systematic review was conducted by the Mucositis Study Group of the Multinational Association of Supportive Care in Cancer/International Society for Oral Oncology (MASCC/ISOO). The body of evidence for each intervention, in each cancer treatment setting, was assigned an evidence level. Based on the evidence level, one of the following three guideline determinations was possible: Recommendation, Suggestion, No guideline possible.

RESULTS

Sixty-four clinical studies across 11 interventions were evaluated. A recommendation was made for the use of recombinant human KGF-1 (palifermin) at a dose of 60 μg/kg per day for 3 days prior to conditioning treatment and for 3 days post-transplant for prevention of oral mucositis in patients receiving high-dose chemotherapy and total body irradiation followed by autologous stem cell transplantation for hematological malignancies. A suggestion was made against using granulocyte macrophage colony-stimulating factor mouthwash for the prevention of oral mucositis in the setting of high-dose chemotherapy followed by autologous or allogeneic stem cell transplantation. No guideline was possible for any other cytokine or growth factor agents due to inconclusive evidence.

CONCLUSIONS

Of the cytokine and growth factor agents studied for oral mucositis, the evidence only supports use of palifermin in the specific population listed above. Additional well-designed research is needed on other cytokine and growth factor interventions and in other cancer treatment settings.

Coran A, Sukhotnik I. Dietary transforming growth factor-beta 2 (TGF-β2) supplementation reduces methotrexate-induced intestinal mucosal injury in a rat

BACKGROUND/AIMS

Dietary supplementation with transforming growth factor-beta (TGF-β) has been proven to minimize intestinal damage and facilitate regeneration after mucosal injury. In the present study, we evaluated the effects of oral TGF-β2 supplementation on intestinal structural changes, enterocyte proliferation and apoptosis following methotrexate (MTX)-induced intestinal damage in a rat and in a cell culture model.

METHODS

Caco-2 cells were treated with MTX and were incubated with increasing concentrations of TGF-β2. Cell apoptosis was assessed using FACS analysis by annexin staining and cell viability was monitored using Trypan Blue assay. Male rats were divided into four experimental groups: Control rats, CONTR- TGF-β rats were treated with diet enriched with TGF-β2, MTX rats were treated with a single dose of methotrexate, and MTX- TGF-β rats were treated with diet enriched with TGF-β2. Intestinal mucosal damage, mucosal structural changes, enterocyte proliferation and enterocyte apoptosis were determined at sacrifice. Real Time PCR and Western blot were used to determine bax and bcl-2 mRNA, p-ERK, β-catenin, IL-1B and bax protein expression.

RESULTS

Treatment of MTX-pretreated Caco-2 cells with TGF-B2 resulted in increased cell viability and decreased cell apoptosis. Treatment of MTX-rats with TGF-β2 resulted in a significant increase in bowel and mucosal weight, DNA and protein content, villus-height (ileum), crypt-depth (jejunum), decreased intestinal-injury score, decreased level of apoptosis and increased cell proliferation in jejunum and ileum compared to the untreated MTX group. MTX-TGF-β2 rats demonstrated a lower bax mRNA and protein levels as well as increased bcl-2 mRNA levels in jejunum and ileum compared to MTX group. Treatment with TGF-β2 also led to increased pERK, IL-1B and β-catenin protein levels in intestinal mucosa.

CONCLUSIONS

Treatment with TGF-β2 prevents mucosal-injury, enhances p-ERK and β-catenin induced enterocyte proliferation, inhibits enterocyte apoptosis and improves intestinal recovery following MTX-induced intestinal-mucositis in rats.

SAMITAL® improves chemo/radiotherapy-induced oral mucositis in patients with head and neck cancer: results of a randomized, placebo-controlled, single-blind Phase II study

PURPOSE

This randomised, placebo-controlled single-blind trial investigated the safety and efficacy of SAMITAL®, a formulation of highly standardised botanical extracts, in the treatment of chemo/radiotherapy-induced oral mucositis (OM) in patients with head and neck cancer.

METHODS

Patients received SAMITAL® or placebo four times daily for up to 50 days during scheduled chemo/radiotherapy. Severity of OM was monitored according to a modified WHO severity scale, and pain and quality-of-life assessments were based on the effect of symptoms of OM on relevant daily activities, according to a visual analogue scale.

RESULTS

Mean scores for the severity of OM were significantly (p < 0.05 versus baseline) reduced from day 31 until the end of treatment in patients treated with SAMITAL® (n = 20). No significant improvement was observed in the placebo group (n = 10). Pain reduction was significant from day 4 till end of treatment with SAMITAL® and from days 7 to 21 in placebo patients. SAMITAL® also significantly improved quality of life, as shown by improvements in scores for relevant daily activities including eating, drinking and sleeping. All SAMITAL® patients completed the treatment period, but no placebo recipients completed treatment. No severe adverse events were observed with SAMITAL®, and systemic absorption of relevant active ingredients was undetectable.

CONCLUSIONS

SAMITAL® significantly decreased the severity of chemo/radiotherapy-induced OM in patients with head and neck cancer, with no treatment-related adverse events. Pain relief lasted through the treatment period, and improvements in quality of life were reflected by the significant benefits of SAMITAL® on activities like drinking, eating and speaking.

Potential role of the NADPH oxidase NOX1 in the pathogenesis of 5-fluorouracil-induced intestinal mucositis in mice

Although NADPH oxidase 1 (NOX1) has been shown to be highly expressed in the gastrointestinal tract, the physiological and pathophysiological roles of this enzyme are not yet fully understood. In the present study, we investigated the role of NOX1 in the pathogenesis of intestinal mucositis induced by the cancer chemotherapeutic agent 5-fluorouracil (5-FU) in mice. Intestinal mucositis was induced in Nox1 knockout (Nox1KO) and littermate wild-type (WT) mice via single, daily administration of 5-FU for 5 days. In WT mice, 5-FU caused severe intestinal mucositis characterized by a shortening of villus height, a disruption of crypts, a loss of body weight, and diarrhea. In Nox1KO mice, however, the severity of mucositis was significantly reduced, particularly with respect to crypt disruption. The numbers of apoptotic caspase-3- and caspase-8-activated cells in the intestinal crypt increased 24 h after the first 5-FU administration but were overall significantly lower in Nox1KO than in WT mice. Furthermore, the 5-FU-mediated upregulation of TNF-α, IL-1β, and NOX1 and the production of reactive oxygen species were significantly attenuated in Nox1KO mice compared with that in WT mice. These findings suggest that NOX1 plays an important role in the pathogenesis of 5-FU-induced intestinal mucositis. NOX1-derived ROS production following administration of 5-FU may promote the apoptotic response through upregulation of inflammatory cytokines.

The chemopreventive and clinically used agent curcumin sensitizes HPV (-) but not HPV (+) HNSCC to ionizing radiation, in vitro and in a mouse orthotopic model

Radiation therapy (RT) plays a critical role in the local-regional control of head and neck squamous cell carcinoma (HNSCC). However, the efficacy of RT in treating HNSCC is limited by severe normal tissue toxicity, predominantly mucositis. One pharmacological approach for increasing the clinical response to RT is the use of radiation response modifiers that preferentially sensitize tumor cells. Previously we demonstrated that curcumin, a natural plant polyphenol, increased the radiation sensitivity of HNSCC cells and that the observed sensitization was dependent on curcumin-mediated inhibition of thioredoxin reductase 1 (TxnRd1) a key cytosolic regulator of redox-dependent signaling. Here, we examined curcumin-induced radiation sensitization in HNSCC cell lines with differing HPV status and expressing different levels of TxnRd1, in vitro. The intrinsic radiation resistance of the HPV (-) cell lines was significantly higher than the HPV (+) cell lines used in our study. Notably, all of the HPV (-) cell lines expressed high levels of TxnRd1 and exhibited higher intrinsic resistance to RT. While curcumin was effective at increasing the radiation response of the resistant HPV (-) cell lines it had no effect on the HPV (+) cells. Based on these findings we employed an orthotopic, HPV (-) HNSCC tumor model in athymic nude mice to examine the effect of combining curcumin with fractionated RT, in vivo. The combination of curcumin feeding and fractionated RT had a significant effect on tumor doubling time and overall animal survival. We therefore propose that curcumin and RT should be considered as a first line treatment of HPV (-) HNSCC.

Effect of salivary stimulation therapies on salivary flow and chemotherapy-induced mucositis: a preliminary study

OBJECTIVE

The objective of this study was to evaluate the effect of salivary stimulation therapies on the salivary flow, oral mucositis, and salivary cytokine levels in patients receiving allogeneic hematopoietic stem cell transplantation.

STUDY DESIGN

Thirty-five eligible patients were randomized into 4 groups: control, mechanical sialogogue, transcutaneous electrical nerve stimulation (TENS) sialogogue, and combined mechanical/electrical sialogogue. Saliva was collected from patients before transplantation and at days 3, 7, and 14 after transplantation. The volume was measured and salivary cytokines were assessed using enzyme-linked immunosorbent assay.

RESULTS

By day 14, resting and stimulated salivary flow levels were diminished. Resting salivary flow rates decreased the most in the control and mechanical groups. In contrast, TENS alone or in combination with mechanical stimulatory therapy benefited the patients. TENS-treated patients showed increase in resting salivary flow. Also, the groups treated with TENS had fewer patients affected by grades 3 and 4 mucositis, and less mucositis was associated with better patient survival (P = .027).

CONCLUSIONS

TENS-associated salivary stimulation therapies minimized the reduction of salivary flow and prevented severe chemotherapy-induced oral mucositis.

Efficacy of royal jelly on methotrexate-induced systemic oxidative stress and damage to small intestine in rats

The aim of this present study is to investigate the mucositis caused by methotrexate (MTX), as well as whether the application of royal jelly (RJ) has a protective effect on oxidative stress. This present study included six groups each consisted of 12 Wistar rats. Distilled water (po: peroral) was given to the 1st group as placebo for 10 days and MTX (20 mg/kg, intraperitoneal: ip) on the 7th day. The 2nd group received RJ (50mg/kg, po) for 10 days and normal saline (NS) instead of MTX. RJ (50mg/kg) was given to the 3rd group for 10 days and MTX on the 7th day. The 4th group received RJ (100 mg/kg, po) for 10 days and NS was given intraperitoneally. RJ (100mg/kg) was given to the 5th group for 10 days and a single dose of MTX. Distilled water was given to the 6th (control) group for 10 days and intraperitoneal NS on the 7th day. Malondialdehyde (MDA), glutathione peroxidase and superoxide dismutase were analyzed in blood samples on the 11th day. Morphological and histopathological changes were examined in the intestinal tissue samples. Villus length and mucosal thickness, as well as the villus length/crypt ratio, were significantly decreased with MTX administration, and the semi-quantitative histological evaluation (SQHE) score was measured high (p<0.001). In addition, a decrease in the antioxidant parameters and an increase in the MDA levels were identified. The villus length and SQHE were significantly different in the groups receiving RJ (p<0.001) as compared to the MTX group. Although RJ addition had no effect on the decreased mucosal thickness and villus/crypt ratio in MTX groups, it caused an improvement in the antioxidant levels and a remarkable decrease in MDA levels. Adding RJ has a decreasing effect on the MTX-induced intestinal damage and it has a suppressive effect on MTX-induced oxidative stress by means of increasing antioxidant enzyme activity and decreasing lipid peroxidation.

Methotrexate modulates tight junctions through NF-κB, MEK, and JNK pathways

OBJECTIVES

Chemotherapy often induces intestinal mucositis, which is associated with an increase in intestinal permeability; however, underlying mechanisms remain incompletely understood. Thus, we aimed to study the regulation of 3 tight junction (TJ) proteins, claudin-1, occludin, and zonula occludens-1, after anticancer treatment.

METHODS

Methotrexate (MTX) was subcutaneously injected for 3 consecutive days in Sprague-Dawley rats to induce intestinal mucositis and was applied on Caco-2 cell monolayers. TJ protein expression and cellular distribution were studied by Western blot and microscopy, respectively. In Caco-2 cells, the paracellular permeability was evaluated by both transepithelial electrical resistance and flux of fluorescein isothiocyanate-dextran marker. Cytokine production and signaling pathways were also assessed.

RESULTS

In MTX-treated rats, the cellular distribution of the 3 TJ proteins was altered and claudin-1 and occludin expression was reduced during the acute phase of mucositis compared with controls. During the recovery phase, these parameters were restored. In vitro, MTX treatment led to an increase in proinflammatory cytokine production at the apical side but did not affect Caco-2 cell apoptosis and necrosis. Increase in paracellular permeability was associated with altered occludin and zonula occludens-1 expression and cellular distribution. All of these alterations were prevented by MEK1 and 2, JNK, and NF-κB inhibitors.

CONCLUSIONS

MTX treatment induced an increase in intestinal permeability partially related to alteration of TJs protein expression and cellular distribution that may be mediated by MAPK and NF-κB pathways. These are potential targets to limit the adverse effects of chemotherapy.

Orofacial diseases in solid organ and hematopoietic stem cell transplant recipients

OBJECTIVE

Solid organ transplant (SOT) and hematopoietic stem cell transplant (HSCT) recipients are at risk of several diseases, principally attributable to immunosuppression. This global overview of SOT/HSCT-associated orofacial diseases is aimed at providing a practical instrument for the oral healthcare management of SOT/HSCT recipients.

METHODS

Literature search was made through MEDLINE. The associations between orofacial diseases and SOT/HSCT were assessed using observational studies and case series and were classified into 'association', 'no association', and 'unclear association'.

RESULTS

Lip/oral cancers, drug-induced gingival overgrowth (DIGO), infections, including hairy leukoplakia and, less frequently, post-transplantation lymphoproliferative disorders (PTLDs) and oral lichenoid lesions of graft-versus-host disease (GVHD), were associated with SOT. Lip/oral cancers, GVHD, mucositis, DIGO, infections and, less frequently, PTLDs were associated with HSCT. Associations of orofacial granulomatosis-like lesions and oral mucosa-associated lymphoid tissue-type lymphoma with SOT, and of pyogenic granuloma and hairy leukoplakia with HSCT were unclear. Periodontal disease and dental caries were not associated with SOT/HSCT. For none of the local treatments was there a strong evidence of effectiveness.

CONCLUSIONS

Solid organ transplant/HSCT recipients are at risk of orofacial diseases. Adequate management of these patients alleviates local symptoms responsible for impaired eating, helps prevent systemic and lethal complications, and helps where dental healthcare has been neglected.

A novel Peptide to treat oral mucositis blocks endothelial and epithelial cell apoptosis

PURPOSE

No effective agents currently exist to treat oral mucositis (OM) in patients receiving chemoradiation for the treatment of head-and-neck cancer. We identified a novel 21-amino acid peptide derived from antrum mucosal protein-18 that is cytoprotective, mitogenic, and motogenic in tissue culture and animal models of gastrointestinal epithelial cell injury. We examined whether administration of antrum mucosal protein peptide (AMP-p) could protect against and/or speed recovery from OM.

METHODS AND MATERIALS

OM was induced in established hamster models by a single dose of radiation, fractionated radiation, or fractionated radiation together with cisplatin to simulate conventional treatments of head-and-neck cancer.

RESULTS

Daily subcutaneous administration of AMP-p reduced the occurrence of ulceration and accelerated mucosal recovery in all three models. A delay in the onset of erythema after irradiation was observed, suggesting that a protective effect exists even before injury to mucosal epithelial cells occurs. To test this hypothesis, the effects of AMP-p on tumor necrosis factor-α-induced apoptosis were studied in an endothelial cell line (human dermal microvascular endothelial cells) as well as an epithelial cell line (human adult low-calcium, high-temperature keratinocytes; HaCaT) used to model the oral mucosa. AMP-p treatment, either before or after cell monolayers were exposed to tumor necrosis factor-α, protected against development of apoptosis in both cell types when assessed by annexin V and propidium iodide staining followed by flow cytometry or ligase-mediated polymerase chain reaction.

CONCLUSIONS

These observations suggest that the ability of AMP-p to attenuate radiation-induced OM could be attributable, at least in part, to its antiapoptotic activity.

5-Fluorouracil induced intestinal mucositis via nuclear factor-κB activation by transcriptomic analysis and in vivo bioluminescence imaging

5-Fluorouracil (5-FU) is a commonly used drug for the treatment of malignant cancers. However, approximately 80% of patients undergoing 5-FU treatment suffer from gastrointestinal mucositis. The aim of this report was to identify the drug target for the 5-FU-induced intestinal mucositis. 5-FU-induced intestinal mucositis was established by intraperitoneally administering mice with 100 mg/kg 5-FU. Network analysis of gene expression profile and bioluminescent imaging were applied to identify the critical molecule associated with 5-FU-induced mucositis. Our data showed that 5-FU induced inflammation in the small intestine, characterized by the increased intestinal wall thickness and crypt length, the decreased villus height, and the increased myeloperoxidase activity in tissues and proinflammatory cytokine production in sera. Network analysis of 5-FU-affected genes by transcriptomic tool showed that the expression of genes was regulated by nuclear factor-κB (NF-κB), and NF-κB was the central molecule in the 5-FU-regulated biological network. NF-κB activity was activated by 5-FU in the intestine, which was judged by in vivo bioluminescence imaging and immunohistochemical staining. However, 5-aminosalicylic acid (5-ASA) inhibited 5-FU-induced NF-κB activation and proinflammatory cytokine production. Moreover, 5-FU-induced histological changes were improved by 5-ASA. In conclusion, our findings suggested that NF-κB was the critical molecule associated with the pathogenesis of 5-FU-induced mucositis, and inhibition of NF-κB activity ameliorated the mucosal damage caused by 5-FU.

Management of cancer therapy-induced oral mucositis

The oral mucosa is a common site for collateral damage of cancer therapies, including radiation, cytotoxic medication, and newer targeted therapies. Ulcerative oral mucositis is typically painful and affects oral functions including speech, and oral intake of food and medications, thus impacting the quality of life. Denuded epithelium may also provide access of oral microbial flora to the deeper tissues and the circulation. Prevention of oral mucositis is an ongoing quest currently with relatively few answers. In this chapter, the present authors discuss the evidence and current practice for prophylaxis and management of this treatment side effect in cancer patients.

Beneficial microbes for premature infants, and children with malignancy undergoing chemotherapy

This review reports the beneficial effects, observed in our clinical studies, of Bifidobacterium breve for premature infants, and children with cancers undergoing chemotherapy. To investigate the protective effects of B. breve (M-16V) as a probiotic on necrotizing enterocolitis (NEC) and infection in premature infants, we carried out a clinical study in 338 very low birth weight infants over a five-year period. These patients were supplemented with B. breve starting several hours after birth (Bifido group). 226 premature infants served as controls. Infants of the Bifido group were administered B. breve in a daily dose of 1×10(9) cells/day. The incidence of NEC was significantly reduced in the Bifido group (nil) compared with that in controls (6 cases, P<0.01). Infection also decreased significantly. Thus, administration of B. breve as a probiotic looks to be a very effective treatment for preventing NEC and infection in preterm infants. Mucositis, also referred to as mucosal barrier injury, is one of the most debilitating side effects of chemotherapy treatment. To evaluate the effects of the administration of B. breve (BBG-01, another strain than that used in the study of premature infants), a clinical study was performed to ascertain whether it attenuated intestinal mucositis in children with cancers on chemotherapy. A placebo-controlled trial was performed in patients with malignancies admitted for chemotherapy (n=42), who were randomised into two groups receiving probiotic or placebo. The frequency of fever and the use of intravenous antibiotics were significantly lower in the Bifido group than the placebo group. The B. breve administration enhanced the colonisation of anaerobes. Disruption of the intestinal microbiota after chemotherapy, such as the increase in the population levels of Enterobacteriaceae, was more pronounced in the placebo group. In conclusion, these data suggest that administration of B. breve is an effective approach to attenuating chemotherapy-induced mucositis in children with cancers. The study results strongly suggest that B. breve administration as a probiotic is an effective therapy for the prevention of NEC and infection in premature infants, and also a promising treatment for attenuating chemotherapy-induced mucositis in children with cancers.

Oral mucositis

Oral mucositis remains one of the most common and troubling side effects of standard chemoradiation regimens used for the treatment of head and neck cancer. Virtually all patients who receive cumulative radiation doses of more than 30 Gy that includes oral mucosal fields will develop the condition. Not only does mucositis cause extreme discomfort, often necessitating opioid analgesia, but it is also associated with increased use of health resources and cost of treatment. The incremental cost of mucositis in patients with head and neck cancer is more than $17 000 (US). Much has been learned about the pathobiology that underlies the condition. The departure from the historical paradigm of direct cell death as being the primary cause for mucosal injury in favor of a more comprehensive view of the impact of chemoradiation on all the cells of the mucosa, has resulted in a picture of mucositis pathogenesis, which is biologically broad based. Although there are currently few treatment options for oral mucositis at the moment, the recognition that its underlying biology is complex has provided a range of treatment options that are currently being developed.

The effect of oral management on the severity of oral mucositis during hematopoietic SCT

Oral mucositis (OM) is a frequent adverse effect of allogenic or autologous hematopoietic SCT. It results from direct toxic injury to the mucosal epithelial cells by the immunosuppressive regimen. Here, we compared the incidence and severity of OM between a group of 24 patients who received proper oral management during hematopoietic SCT and a group of 24 who did not. The oral management group received pre-hematopoietic SCT instruction on oral care and an oral examination in the clean room. Differences in the incidence and severity of OM between the two groups were examined statistically. OM was observed in 14 (58.3%) patients in the oral management group and 22 (91.6%) in the control group. The median of the OM score was 1 for the oral management group (range 0 to 3) and 2 for the control group (range 0 to 3). There was a significant difference in the OM score (P<0.05) and in the incidence of OM between the two groups (P<0.01). This study shows that oral management may decrease the occurrence of OM. Our results also suggest that it is important to include an oral management provider on the hematopoietic SCT team.

Trefoil factor family peptides are increased in the saliva of children with mucositis

BACKGROUND

Mucositis is a painful ulcerative condition of the oral cavity and gastrointestinal tract, occurring in association with chemotherapy and radiotherapy regimes. Trefoil factor family peptides (TFF, trefoil peptides), present in saliva, contribute to epithelial restitution and repair and are therefore potentially important in the healing phase of mucositis. This study aimed to assess any changes in the levels of trefoil peptides in oncology patients with and without mucositis.

METHODS

Saliva was collected from healthy children, pretreatment oncology patients, neutropenic patients on treatment with no oral disease and mucositic patients. TFF1, 2 and 3 were quantified using ELISA.

RESULTS

In healthy children TFF2 and 3 were positively correlated with age (r = 0.454, p = 0.01 for TFF2; r = 0.410, p = 0.05 for TFF3 Spearman rank correlation). TFF3 was higher in mucositis compared to all other groups. A linear regression prediction model indicated that TFF3, but not TFF1 and TFF2, was significantly different in mucositic and healthy controls, suggesting an altered pattern of trefoil peptide secretion (p = 0.021).

CONCLUSIONS

This study is the first to focus on trefoil peptides in paediatric saliva. It shows the correlation between TFF2, TFF3 and age in healthy children. Paediatric mucositis disease occurs in the presence of increased concentrations and an altered pattern of trefoil peptides.

Three-dimensional spheroid culture of human gingiva-derived mesenchymal stem cells enhances mitigation of chemotherapy-induced oral mucositis

Mesenchymal stem cells (MSCs) are capable of regenerative and immunomodulatory functions in cell-based therapies in a variety of human diseases and injuries; however, their therapeutic efficacy and potential side effects remain major obstacles in clinical applications. We report here a 3D spheroid culture approach to optimize stem cell properties and therapeutic effects of human gingiva-derived mesenchymal stem cells (GMSCs) in mitigation of experimental oral mucositis. Under growth condition of ultra-low attachment, GMSCs spontaneously aggregated into 3D spheroids and exhibited distinct early stem cell phenotype characterized by elevated expression Stro-1 and CXC chemokine receptor 4 (CXCR-4) as well as OCT-4 and Nanog, 2 important transcriptional factors relevant to stem cell properties, and decreased expression of MSC-associated markers, including CD29, CD90, and CD105. Functionally, spheroid GMSCs are capable of enhanced multipotency and augmented secretion of several chemokines and cytokines relevant to cell migration, survival, and angiogenesis. More importantly, spheroid GMSCs expressed increased levels of reactive oxygen species, hypoxia-inducible factor (HIF)-1 and -2α, and manganese superoxide dismutase, which correlated with improved resistance to oxidative stress-induced apoptosis. Using an in vivo murine model of chemotherapy-induced oral mucositis, we demonstrated that spheroid-derived GMSCs possessed better therapeutic efficacy than their adherent cells in reversing body weight loss and promoting the regeneration of disrupted epithelial lining of the mucositic tongues. These findings suggest that 3D spheroid culture allows early stemness preservation and potentially precondition GMSCs for enhanced mitigation of oral mucositis.

Single-Dose Prevention or Short-Term Treatment with Fibroblast Growth Factor-20 (CG53135-05)Reduces the Severity and Duration of Oral Mucositis

Oral mucositis (OM) is a treatment-limiting condition associated with myelosupressive chemotherapy and radiation therapy. The objective of this study was to evaluate the activity of recombinant human fibroblast growth factor-20 (FGF-20 or CG53135-05) in the prevention and treatment of OM in experimental animals. Oral mucositis was induced in hamsters with 5-fluorouracil (5-FU; 60 mg/kg) on days -4 and -2, followed by targeted irradiation with 30 Gy on day 0. Oral mucositis was scored every other day using severity scores of 0-5. To test for prevention of OM, animals received varying doses of FGF-20 on day 1 or days 1 and 2 after irradiation before the development of symptoms. To test the effects of FGF-20 on established mucositis, animals were allowed to develop early OM (score of 2) before treatment initiation. Animals then received FGF-20 by intraperitoneal (i.p.) administration (12 mg/kg) for 1, 2, 3, or 4 consecutive days. When prevention of OM was tested, administration of FGF-20 (12 mg/kg i.p.) on day 1 or days 1 and 2 resulted in significant reduction in duration of severe OM to 26% (P < 0.003) or 29.4% (P <0.018) of cumulative days, respectively, compared with untreated control animals, which spent 40.2% of cumulative days with OM scores >/= 3. When the effects of FGF-20 on established mucositis were tested, treatment of animals with FGF-20 for 2, 3, or 4 consecutive days resulted in significant reduction of severe OM to 27.4%, 29.2%, or 18.5% of days, respectively, compared with vehicle-treated control animals, which spent 41.1% of cumulative days with OM scores >/=3 (P < 0.05). These findings support the utility of FGF-20 as a single-dose agent in the prevention of OM. In addition, the positive effects of FGF-20 on established mucositis may permit treatment of patients with OM who may not benefit from prophylactic agents.

Role of AMP-18 in oral mucositis

Oral mucositis (OM) is a devasting toxicity associated with cytotoxic cancer therapy. Antrum mucosal protein (AMP)-18 and a synthetic peptide surrogate, exhibit cell protective and mitogenic properties in in vitro and in vivo models of gastrointestinal epithelial cell injury. The mucosal barrier-protective effects may be mediated by AMP-18's capacity to increase accumulation of specific tight junction (TJ) and adherens junction proteins, and also protect against their loss after injury. Here we asked if AMP peptide could protect the oral mucosa and speed healing from radiation-induced injury. We found AMP peptide prevented radiation-induced OM in a murine model. The peptide also stimulated HaCaT cell growth used to model the oral mucosa. Binding of recombinant human (rh) AMP-18 to the plasma membrane of keratinocytes in normal human oral mucosal tissue suggested that its effects may be receptor mediated. Using an immobilized His-tagged rhAMP-18 fusion protein the receptor was identified as the cholecystokinin-B/gastrin receptor (CCKBR) by affinity purification and mass spectrometry analysis. CCKBR was expressed and co-immunoprecipitated with exogenous rhAMP-18 in diverse epithelial cell lines. Immunofluorescence staining revealed that rhAMP-18 colocalized with CCKBR on the surface of CCKBR-transfected cells. Furthermore, rhAMP-18-stimulated signaling pathways were blocked by a CCKBR-specific antagonist, YM022. rhAMP-18 enhanced viability and growth of CCKBR-transfected, but not empty vector-transfected cells. These results suggest the importance of epithelial junctional integrity in the pathogenesis of OM and demonstrate that AMP-18, by targeting TJ proteins through the activation of CCKBR, could provide a novel strategy for the prevention and treatment of OM.

Interleukin 1 receptor antagonist reduces lethality and intestinal toxicity of 5-Fluorouracil in a mouse mucositis model

Chemotherapy induced intestinal mucositis is still an unmet medical problem. 5-fluorouracil (5-Fu), a chemotherapy drug, was used to create the animal model of mucositis. Global gene expression array was applied to identify genetic signals involved in the pathogenesis of mucositis. Interleukin 1 receptor antagonist (IL-1Ra) was one of the candidates with the characteristic gene expression profile. Its temporal expression pattern correlated to the damage and regeneration phase of the small intestine after a single injection of 5-Fu to mice. Administration of recombinant IL-1Ra to the mouse model of intestinal mucositis induced by 5-Fu demonstrated its therapeutic effects to the symptoms and pathology of the disease. The IL-1Ra treatment reduced the acute lethality, accelerated their body weight recovery, and eliminated severe diarrhea. The symptomatic benefits were supported by the pathological benefits, in which the mice treated with IL-1Ra has less damage and faster recovery of the structure integrity of their small intestine than that of the mice treated with vehicle control. To deliver the therapeutics to the unmet medical condition, further mechanism and translational studies of IL-1Ra in the settings of chemotherapy induced intestinal mucositis are warranted.