Chemotherapy-induced mucositis: The role of mucin secretion and regulation, and the enteric nervous system

Probiotics and Probiotic-like Agents against Chemotherapy-Induced Intestinal Mucositis: A Narrative Review

Cancer chemotherapy has allowed many patients to survive, but not without risks derived from its adverse effects. Drugs, such as 5-fluorouracil, irinotecan, oxaliplatin, methotrexate, and others, as well as different drug combinations trigger intestinal mucositis that may cause or contribute to anorexia, pain, diarrhea, weight loss, systemic infections, and even death. Dysbiosis is a hallmark of chemotherapy-induced intestinal mucositis and diarrhea, and, therefore, strategies aimed at modulating intestinal microbiota may be useful to counteract and prevent those dreadful effects. This narrative review offers an overview of the studies performed to test the efficacy of probiotics and probiotic-like agents against chemotherapy-induced intestinal mucositis and its consequences. Microbiota modulation through the oral administration of different probiotics (mainly strains of Lactobacillus and Bifidobacterium), probiotic mixtures, synbiotics, postbiotics, and paraprobiotics has been tested in different animal models and in some clinical trials. Regulation of dysbiosis, modulation of epithelial barrier permeability, anti-inflammatory effects, modulation of host immune response, reduction of oxidative stress, or prevention of apoptosis are the main mechanisms involved in their beneficial effects. However, the findings are limited by the great heterogeneity of the preclinical studies and the relative lack of studies in immunocompromised animals, as well as the scarce availability of results from clinical trials. Despite this, the results accumulated so far are promising. Hopefully, with the aid of these agents, intestinal mucositis will be less impactful to the cancer patient in the near future.

Soybean glycinin and β-conglycinin damage the intestinal barrier by triggering oxidative stress and inflammatory response in weaned piglets

PURPOSE

Soybean glycinin (11S) and β-conglycinin (7S) are major antigenic proteins in soybean and can induce a variety of allergic reactions in the young animals. This study aimed to investigate the effect of 7S and 11S allergens on the intestine of piglets.

METHODS

Thirty healthy 21-day-old weaned "Duroc × Long White × Yorkshire" piglets were randomly divided into three groups fed with the basic diet, the 7S supplemented basic diet, or the 11S supplemented basic diet for 1 week. Allergy markers, intestinal permeability, oxidative stress, and inflammatory reactions were detected, and we observed different sections of intestinal tissue. The expressions of genes and proteins related to NOD-like receptor thermal protein domain associated protein 3 (NLRP-3) signaling pathway were detected by IHC, RT-qPCR, and WB.

RESULTS

Severe diarrhea and decreased growth rate were observed in the 7S and 11S groups. Typical allergy markers include IgE production and significant elevations of histamine and 5-hydroxytryptamine (5-HT). More aggressive intestinal inflammation and barrier dysfunction were observed in the experimental weaned piglets. In addition, 7S and 11S supplementation increased the levels of 8-hydroxy-2 deoxyguanosine (8-OHdG) and nitrotyrosine, triggering oxidative stress. Furthermore, higher expression levels of NLRP-3 inflammasome ASC, caspase-1, IL-1β, and IL-18 were observed in the duodenum, jejunum, and ileum.

CONCLUSION

We confirmed that 7S and 11S damaged the intestinal barrier of weaned piglets and may be associated with the onset of oxidative stress and inflammatory response. However, the molecular mechanism underlying these reactions deserves further study.

Cancer chemotherapy and beyond: Current status, drug candidates, associated risks and progress in targeted therapeutics

Cancer is an abnormal state of cells where they undergo uncontrolled proliferation and produce aggressive malignancies that causes millions of deaths every year. With the new understanding of the molecular mechanism(s) of disease progression, our knowledge about the disease is snowballing, leading to the evolution of many new therapeutic regimes and their successive trials. In the past few decades, various combinations of therapies have been proposed and are presently employed in the treatment of diverse cancers. Targeted drug therapy, immunotherapy, and personalized medicines are now largely being employed, which were not common a few years back. The field of cancer discoveries and therapeutics are evolving fast as cancer type-specific biomarkers are progressively being identified and several types of cancers are nowadays undergoing systematic therapies, extending patients' disease-free survival thereafter. Although growing evidence shows that a systematic and targeted approach could be the future of cancer medicine, chemotherapy remains a largely opted therapeutic option despite its known side effects on the patient's physical and psychological health. Chemotherapeutic agents/pharmaceuticals served a great purpose over the past few decades and have remained the frontline choice for advanced-stage malignancies where surgery and/or radiation therapy cannot be prescribed due to specific reasons. The present report succinctly reviews the existing and contemporary advancements in chemotherapy and assesses the status of the enrolled drugs/pharmaceuticals; it also comprehensively discusses the emerging role of specific/targeted therapeutic strategies that are presently being employed to achieve better clinical success/survival rate in cancer patients.

Patient-derived organoids identify an apico-basolateral polarity switch associated with survival in colorectal cancer

The metastatic progression of cancer remains a major issue in patient treatment. Yet, the molecular and cellular mechanisms underlying this process remains unclear. Here, we use primary explants and organoids from patients harboring mucinous colorectal carcinoma (MUC CRC), a poor prognosis histological form of digestive cancers, to study the architecture, invasive behavior and chemoresistance of tumor cell intermediates. We report that these tumors maintain a robust apico-basolateral polarity as they spread in the peritumoral stroma or organotypic collagen-I gels. We identified two distinct topologies: MUC CRCs either display a conventional "apical-in" polarity or, more frequently, harbor an inverted "apical-out" topology. Transcriptomic analyses combined with interference experiments on organoids showed that TGFb and focal adhesion signaling pathways are the main drivers of polarity orientation. Finally, this apical-out topology is associated with increased resistance to chemotherapeutic treatments in organoids and decreased patient survival in the clinic. Thus, patient-derived organoids have the potential to bridge histological, cellular and molecular analyses to decrypt onco-morphogenic programs and stratify cancer patients.

Mechanisms of Chemotherapy-Induced Neurotoxicity

Since the first clinical trials conducted after World War II, chemotherapeutic drugs have been extensively used in the clinic as the main cancer treatment either alone or as an adjuvant therapy before and after surgery. Although the use of chemotherapeutic drugs improved the survival of cancer patients, these drugs are notorious for causing many severe side effects that significantly reduce the efficacy of anti-cancer treatment and patients’ quality of life. Many widely used chemotherapy drugs including platinum-based agents, taxanes, vinca alkaloids, proteasome inhibitors, and thalidomide analogs may cause direct and indirect neurotoxicity. In this review we discuss the main effects of chemotherapy on the peripheral and central nervous systems, including neuropathic pain, chemobrain, enteric neuropathy, as well as nausea and emesis. Understanding mechanisms involved in chemotherapy-induced neurotoxicity is crucial for the development of drugs that can protect the nervous system, reduce symptoms experienced by millions of patients, and improve the outcome of the treatment and patients’ quality of life.

Targeting Enteric Neurons and Plexitis for the Management of Inflammatory Bowel Disease

Ulcerative colitis (UC) and Crohn's disease (CD) are pathological conditions with an unknown aetiology that are characterised by severe inflammation of the intestinal tract and collectively referred to as inflammatory bowel disease (IBD). Current treatments are mostly ineffective due to their limited efficacy or toxicity, necessitating surgical resection of the affected bowel. The management of IBD is hindered by a lack of prognostic markers for clinical inflammatory relapse. Intestinal inflammation associates with the infiltration of immune cells (leukocytes) into, or surrounding the neuronal ganglia of the enteric nervous system (ENS) termed plexitis or ganglionitis. Histological observation of plexitis in unaffected intestinal regions is emerging as a vital predictive marker for IBD relapses. Plexitis associates with alterations to the structure, cellular composition, molecular expression and electrophysiological function of enteric neurons. Moreover, plexitis often occurs before the onset of gross clinical inflammation, which may indicate that plexitis can contribute to the progression of intestinal inflammation. In this review, the bilateral relationships between the ENS and inflammation are discussed. These include the effects and mechanisms of inflammation-induced enteric neuronal loss and plasticity. Additionally, the role of enteric neurons in preventing antigenic/pathogenic insult and immunomodulation is explored. While all current treatments target the inflammatory pathology of IBD, interventions that protect the ENS may offer an alternative avenue for therapeutic intervention.

Impact of chemotherapy-induced enteric nervous system toxicity on gastrointestinal mucositis

PURPOSE OF REVIEW

Chemotherapy is a first-line treatment for many cancers; however, its use is hampered by a long list of side-effects. Gastrointestinal mucositis is a common and debilitating side-effect of anticancer therapy contributing to dose reductions, delays and cessation of treatment, greatly impacting clinical outcomes. The underlying pathophysiology of gastrointestinal mucositis is complex and likely involves several overlapping inflammatory, secretory and neural mechanisms, yet research investigating the role of innervation in gastrointestinal mucositis is scarce. This review provides an overview of the current literature surrounding chemotherapy-induced enteric neurotoxicity and discusses its implications on gastrointestinal mucositis.

RECENT FINDINGS

Damage to the intrinsic nervous system of the gastrointestinal tract, the enteric nervous system (ENS), occurs following chemotherapeutic administration, leading to altered gastrointestinal functions. Chemotherapeutic drugs have various mechanisms of actions on the ENS. Oxidative stress, direct toxicity and inflammation have been identified as mechanisms involved in chemotherapy-induced ENS damage. Enteric neuroprotection has proven to be beneficial to reduce gastrointestinal dysfunction in animal models of oxaliplatin-induced enteric neuropathy.

SUMMARY

Understanding of the ENS role in chemotherapy-induced mucositis requires further investigation and might lead to the development of more effective therapeutic interventions for prevention and treatment of chemotherapy-induced gastrointestinal side-effects.

The morphological changes of the colonic goblet cells and mucin profile in oncohematological patients under Epirubicin-based chemotherapy

Changes in the lining of the small intestine following chemotherapy have been extensively studied, although also occurs in the large intestine. The aim of this study was to assess the consequences of Epirubicin-based therapy on goblet cells (GCs) and mucus production on colonic mucosa, immediately and after short-time of chemotherapy administration to oncohematological patients, by clinical and histopathological analysis. We assessed the mucus production, composition, and distribution by Alcian Blue (pH 2.5)–Periodic Acid–Schiff (PAS) staining, alongside with the immunoexpression of mucin (MUC)2, MUC4 and inflammatory markers in a series of oncohematological patients, immediately and after short-time of Epirubicin-based chemotherapy cumulative therapy cessation. We showed that GCs number decrease slightly at 48 hours, while mucous secretion became mixed (with a few neutral) after three weeks. Overall, the secretion was increased immediately after the Epirubicin administration, due to the activation of inflammatory pathways, assessed by increased immunostaining of tumor necrosis factor-alpha (TNF-α) at 48 hours. The MUC2 and MUC4 showed a decreased immunoexpression at 48 hours after the Epirubicin administration compared to controls and partially restored three weeks after the cessation. Overall, it is highly plausible that all these key players revolve around the chemotherapy-induced mucositis in oncohematological patients and highlights the morphofunctional particularities of the GCs, which further modulates the clinical outcome of the patient.

Investigation of Changes in Saliva in Radiotherapy-Induced Head Neck Cancer Patients

The intact function of the salivary glands is of utmost importance for oral health. During radiotherapy in patients with head and neck tumors, the salivary glands can be damaged, causing the composition of saliva to change. This leads to xerostomia, which is a primary contributor to oral mucositis. Medications used for protective or palliative treatment often show poor efficacy as radiation-induced changes in the physico-chemical properties of saliva are not well understood. To improve treatment options, this study aimed to carefully examine unstimulated whole saliva of patients receiving radiation therapy and compare it with healthy unstimulated whole saliva. To this end, the pH, osmolality, electrical conductivity, buffer capacity, the whole protein and mucin concentrations, and the viscoelastic and adhesive properties were investigated. Moreover, hyaluronic acid was examined as a potential candidate for a saliva replacement fluid. The results showed that the pH of radiation-induced saliva shifted from neutral to acidic, the osmolality increased and the viscoelastic properties changed due to a disruption of the mucin network and a change in water secretion from the salivary glands. By adopting an aqueous 0.25% hyaluronic acid formulation regarding the lost properties, similar adhesion characteristics as in healthy, unstimulated saliva could be achieved.

Chemotherapy-induced diarrhoea in dogs and its management with smectite: Results of a monocentric open-label randomized clinical trial

Chemotherapy-induced diarrhoea (CID) is a frequent chemotherapy adverse event in dogs. Yet, there is currently no consensus regarding its management. Smectite is a natural medical clay, widely used in the treatment of acute diarrhoea in humans. The objectives of this study were to assess the efficacy of smectite in the management of CID in dogs, and to collect epidemiological data on CID. For each episode of diarrhoea, dogs were randomized into two management groups: Smectite group, receiving smectite at 0.5 g/kg PO per day divided in two to three doses initiated at the start of CID; control group, without initial medication. In both groups, rescue metronidazole was prescribed if CID progressed or was not improved within 48 hours. Sixty dogs were recruited and received 426 chemotherapy administrations between June 2017 and March 2019. The incidence rate of CID was 110/426 (25.8%, 95% CI: 21.7%-30.2%), and significantly differed between the chemotherapeutic drugs administered (P < .001). Metronidazole was administered in 5/54 events (9.3%, 95% CI: 3.1%-20.3%) in the smectite group and in 40/56 events (71.4%, 95% CI: 57.5%-82.3%) in the control group (P < .001). The time to resolution of diarrhoea was shorter (P < .001) in the smectite group (median: 19.5 hours, interquartile range [IQR]: 13.5-32 hours) compared with the control group (median: 53 hours, IQR: 31.5-113.5 hours). The results of this study support the administration of smectite in the first-line management of CID in dogs.

Pitfalls and novel experimental approaches to optimize microbial interventions for chemotherapy-induced gastrointestinal mucositis

PURPOSE OF REVIEW

There is a growing number of studies implicating gut dysbiosis in mucositis development. However, few studies have shed light on the causal relationship limiting translational potential. Here, we detail the key supportive evidence for microbial involvement, candidate mechanisms by which the microbiome may contribute to mucositis and emerging approaches to model host-microbe interactions with clinical relevance and translational potential.

RECENT FINDINGS

Synthesis of existing clinical data demonstrate that modulating the microbiome drastically alters the development and severity of mucositis, providing a strong rationale for its involvement. Review of the literature revealed potential microbiome-dependent mechanisms of mucosal injury including altered drug metabolism, bile acid synthesis and regulation of the intestinal barrier. Current studies are limited in their mechanistic insight due to cross-sectional and would benefit from longitudinal analyses and baseline phenotyping.

SUMMARY

The causative role of the microbiome in mucositis development remains unclear. Future studies must adopt comprehensive microbial analyses with functional assessment, and utilize emerging ex-vivo models to interrogate host-microbe interactions in mucositis.

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

PURPOSE OF REVIEW

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

RECENT FINDINGS

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

SUMMARY

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

Mitigation of Radiation-induced Gastrointestinal System Injury using Resveratrol or Alpha-lipoic Acid: A Pilot Histopathological Study

AIM

In this study, we aimed to determine possible mitigation of radiationinduced toxicities in the duodenum, jejunum and colon using post-exposure treatment with resveratrol and alpha-lipoic acid.

BACKGROUND

After the bone marrow, gastrointestinal system toxicity is the second critical cause of death following whole-body exposure to radiation. Its side effects reduce the quality of life of patients who have undergone radiotherapy. Resveratrol has an antioxidant effect and stimulates DNA damage responses (DDRs). Alpha-lipoic acid neutralizes free radicals via the recycling of ascorbic acid and alpha-tocopherol.

OBJECTIVE

This study is a pilot investigation of the mitigation of enteritis using resveratrol and alpha-lipoic acid following histopathological study.

METHODS

60 male mice were randomly assigned to six groups; control, resveratrol treatment, alpha-lipoic acid treatment, whole-body irradiation, irradiation plus resveratrol, and irradiation plus alpha-lipoic acid. The mice were irradiated with a single dose of 7 Gy from a cobalt-60 gamma-ray source. Treatment with resveratrol or alpha-lipoic acid started 24 h after irradiation and continued for 4 weeks. All mice were sacrificed after 30 days for histopathological evaluation of radiation-induced toxicities in the duodenum, jejunum and colon.

RESULTS AND DISCUSSION

Exposure to radiation caused mild to severe damages to vessels, goblet cells and villous. It also led to significant infiltration of macrophages and leukocytes, especially in the colon. Both resveratrol and alpha-lipoic acid were able to mitigate morphological changes. However, they could not mitigate vascular injury.

CONCLUSION

Resveratrol and alpha-lipoic acid could mitigate radiation-induced injuries in the small and large intestine. A comparison between these agents showed that resveratrol may be a more effective mitigator compared to alpha-lipoic acid.

Irinotecan-Induced Mucositis Is Associated with Goblet Cell Dysregulation and Neural Cell Damage in a Tumour Bearing DA Rat Model

Irinotecan-induced mucositis is a major oncological problem. Goblet cells secrete mucus, protecting the intestinal mucosa, with secretion altered during mucositis. The enteric nervous system is involved in regulating gut motility and secretion. The aim of this study was to determine whether enteric neural cells and goblet cells are altered following irinotecan treatment. Tumour-bearing Dark Agouti rats were administered a single dose of 175 mg/kg of irinotecan intraperitoneally and 0.01 mg/kg atropine subcutaneously. Experimental and untreated control rats were killed at times 6, 24, 48, 72, 96 and 120 h after treatment. Jejunum and colon samples were formalin fixed. Haematoxylin and eosin staining, Alcian Blue-PAS staining, and immunohistochemistry with S-100 antibody (neural cell marker) were carried out. Statistical analyses were carried out using Kruskal-Wallis test with Dunns post test, Mann Whitney U test and nonlinear regression. Total goblet cells decreased at 72 h compared with controls in the colon (p < 0.05). The percentage of cavitated goblet cells decreased compared to all other time points at 120 h in the colon. The number of S-100 positive cells in the submucosal plexus decreased in the colon (p = 0.0046) and in the myenteric plexus of the jejunum and colon (p = 0.0058 and p = 0.0022, respectively), when comparing treated with control. Enteric ganglia in the myenteric plexus of the jejunum decreased at 24 h and 96 h. Irinotecan-induced mucositis is associated with increases in mucus secretion, and enteric neural cell change. These changes may contribute to the pathophysiology of mucositis through the dysregulation of neural signalling.

Association between breast cancer chemotherapy, oral health and chronic dental infections: a pilot study

Breast cancer has developed to become the leading type of cancer in females. For this study, 80 women were examined after chemotherapy for breast cancer and compared to 80 healthy age-matched women. This cross-sectional study comprised a dental examination with number of teeth, caries frequency (DMFT) and the presence of periodontal diseases (PSI). With the help of X-rays (OPG), the number of root canal fillings and apical lesions (LEO/LPO) were recorded. Furthermore, the education level, body mass index (BMI), smoking habits and general health conditions were recorded. All women completed questionnaires on oral health-related quality of life (OHIP-G14) and general well-being (HADS-D). To assess the influence of cancer therapy on oral health parameters, appropriate generalized linear models were fitted with disease status as main explanatory variable, adjusting for age and education. For OHIP and HADS, we additionally adjusted for number of missing teeth. The examined 160 women showed a comparable mean age (60.4 years) and an average BMI of 24.6. Cancer patients showed a higher risk for missing teeth (p < 0.001) and more apical lesions (p < 0.0041), particularly those of endodontic origin without root canal fillings (p = 0.0046), than the control women. The general well-being of cancer patients was significantly reduced with a HADS score of 9.4 for women with breast cancer compared to 5.3 for the healthy control. This study suggests that women after breast cancer chemotherapy are inclined to have a poorer oral health status with more missing teeth and apical lesions. Therefore, tightly scheduled dental recall visits should be recommended.

Multicenter randomized, double-blind controlled trial to evaluate the efficacy of laser therapy for the treatment of severe oral mucositis induced by chemotherapy in children: laMPO RCT

OBJECTIVES

To demonstrate the efficacy of laser photobiomodulation (PBM) compared to that of placebo on severe oral mucositis (OM) in pediatric oncology patients. The primary objective was the reduction of OM grade (World Health Organization [WHO] scale) 7 days after starting PBM. Secondary objectives were reduction of pain, analgesic consumption, and incidence of side effects.

METHODS

One hundred and one children with WHO grade > 2 chemotherapy-induced OM were enrolled in eight Italian hospitals. Patients were randomized to either PBM or sham treatment for four consecutive days (days +1 to +4). On days +4, +7, and +11, OM grade, pain (following a 0-10 numeric pain rating scale, NRS) and need for analgesics were evaluated by an operator blinded to treatment.

RESULTS

Fifty-one patients were allocated to the PBM group, and 50 were allocated to the sham group. In total, 93.7% of PBM patients and 72% of sham patients had OM grade < 3 WHO on day +7 (P = 0.01). A significant reduction of pain was registered on day +7 in the PBM versus sham group (NRS 1 [0-3] vs. 2.5 [1-5], P < 0.006). Reduced use of analgesics was reported in the PBM group, although it was not statistically significant. No significant adverse events attributable to treatment were recorded.

CONCLUSIONS

PBM is a safe, feasible, and effective treatment for children affected by chemotherapy-induced OM, as it accelerates mucosal recovery and reduces pain.

Alleviation of 5-fluorouracil-induced intestinal mucositis in rats by vitamin E via targeting oxidative stress and inflammatory markers

BackgroundIntestinal mucositis is a major concern related with cancer therapy. It is well established that overproduction of reactive oxygen species and inflammatory mediators plays vital role in the pathogenesis of mucositis. The aim of the study was to investigate the modulatory effect of vitamin E (vit. E) on 5-fluorouracil (5-FU)-induced intestinal mucositis by targeting oxidative stress and inflammatory markers in rats. MethodsRats were randomly divided into four groups of six animals each. All four-group animals received normal standard diet and water throughout the experimental period which last up to 10 days. Rats were gavaged with vit. E (300 mg/kg b. wt.) daily for 10 days (day 1-10) and were given intraperitoneal injection of 5-FU (150 mg/kg b. wt.) or saline (control) on day 8 to induce mucositis. Results We found that vit. E supplementation ameliorated 5-FU-induced lipid peroxidation, myeloperoxidase activity, activation of nuclear factor κB, expression of cyclooxygenase-2, inducible nitric oxide synthase and mucin depletion. Vit. E administration also attenuated 5-FU-induced histological anomalies such as neutrophil infiltration, loss of cellular integrity, villus and crypt deformities. ConclusionsFindings of the study suggest that vit. E inhibits 5-FU-induced mucositis via modulation of oxidative stress, activation of redox sensitive transcription factor and its downstream targets.

Alterations in the small intestinal wall and motor function after repeated cisplatin in rat

BACKGROUND

Gastrointestinal adverse effects occurring during cancer chemotherapy are well known and feared; those persisting once treatment has finished are relatively unknown. We characterized the alterations occurring in the rat small intestine, after repeated treatment with cisplatin.

METHODS

Male Wistar rats received saline or cisplatin (2 mg kg^-1  week^-1 , for 5 weeks, ip). Gastric motor function was studied non-invasively throughout treatment (W1-W5) and 1 week after treatment finalization (W6). During W6, upper gastrointestinal motility was also invasively studied and small intestinal samples were collected for histopathological and molecular studies. Structural alterations in the small intestinal wall, mucosa, submucosa, muscle layers, and lymphocytic nodules were histologically studied. Periodic acid-Schiff staining and immunohistochemistry for Ki-67, chromogranin A, and neuronal-specific enolase were used to detect secretory, proliferating, endocrine and neural cells, respectively. The expression of different markers in the tunica muscularis was analyzed by RT/qPCR.

KEY RESULTS

Repeated cisplatin induced motility alterations during and after treatment. After treatment (W6), the small intestinal wall showed histopathological alterations in most parameters measured, including a reduction in the thickness of circular and longitudinal muscle layers. Expression of c-KIT (for interstitial cells of Cajal), nNOS (for inhibitory motor neurons), pChAT, and cChAT (for excitatory motor neurons) increased significantly (although both ChATs to a lesser extent).

CONCLUSIONS & INFERENCES

Repeated cisplatin induces relatively long-lasting gut dysmotility in rat associated with important histopathological and molecular alterations in the small intestinal wall. In cancer survivors, the possible chemotherapy-induced histopathological, molecular, and functional intestinal sequelae should be evaluated.

Altered systemic bioavailability and organ distribution of azathioprine in methotrexate-induced intestinal mucositis in rats

OBJECTIVE

Intestinal mucositis is a significant problem haunting clinicians for decades. One of the major reasons for its occurrence is high-dose chemotherapy. The study is aimed at investigating effect of intestinal mucositis on pharmacokinetics, organ distribution, and bioavailability of azathioprine (AZA) (6-mercaptopurine).

MATERIALS AND METHODS

Intestinal mucositis was induced with methotrexate (MTX) (2.5 mg/kg). The oral absorption of AZA and 6-mercaptopurine (metabolite) levels were determined in control and MTX-treated rats: ex vivo (noneverted sac technique) and in vivo (pharmacokinetics and organ-distribution) using high-performance liquid chromatography. Immunohistochemistry was conducted to evaluate peptide transporter expression on luminal membrane of small intestine.

RESULTS

Intestinal permeation of AZA into systemic circulation of rats was lower after MTX administration, widely found in intestinal segments of mucositis-induced rats leading to decline in systemic bioavailability of AZA. Immunohistochemistry findings indicated diminution of peptide transporter expression representing hampered absorption of drugs absorbed via this transporter.

CONCLUSION

Study outcome has thrown light on altered fate of AZA when administered to individuals with mucositis which suggests modified drug therapy. These findings can further be investigated in different drug classes which might be administered concomitantly in mucositis and study outcome can be further confirmed in mucositis patients in clinical practice also.

Host-microbe cross talk in cancer therapy

PURPOSE OF REVIEW

Microbiota secrete a multitude of factors that either confer virulence or promote colonization because they are continuously challenged by host immune responses. The dynamic interplay between the host's immune response and microbiota eventually determines the outcome for the host: health or disease. Toll-like receptors (TLRs) play a key role in this interplay as they can recognize both microbial and host-derived ligands on the basis of the context in which recognition occurs.

RECENT FINDINGS

Evidence is accumulating that conventional cancer therapies alter interactions and cross talks between the host and microbiota. This has been shown for intestinal mucositis, a common side-effect of various cancer therapies. Advances have been made in the development of new and less toxic cancer strategies. One promising field is immunotherapy on the basis of TLR activation through recognition of microbial-associated molecular patterns.

SUMMARY

Evidence is emerging, indicating that existing cancer therapies have implications on the composition and functionality of the host-microbiota environment. This may favor the colonization of pathogens and build up the overall toxicity of the drug. Exploitation of the host-microbiota cross talks mediated by TLRs is an emerging and promising field in the search for new, less toxic anticancer strategies.

Multi-institutional, randomized, double-blind, placebo-controlled trial to assess the efficacy of a mucoadhesive hydrogel (MuGard) in mitigating oral mucositis symptoms in patients being treated with chemoradiation therapy for cancers of the head and neck

BACKGROUND

The objective of this trial was to determine how a mucoadhesive hydrogel (MuGard), a marketed medical device, would fare when tested with the strictness of a conventional multi‐institutional, double‐blind, randomized, placebo‐controlled study format.

METHODS

A total of 120 subjects planned to receive chemoradiation therapy (CRT) for treatment of head and neck cancers were randomized to receive either MuGard or sham control rinse (SC) during CRT. Subjects completed the validated Oral Mucositis Daily Questionnaire. Weight, opiate use, and World Health Organization (WHO) oral mucositis (OM) scores were recorded. Subjects who dosed at least once daily during the first 2.5 weeks of CRT were included in the efficacy analysis.

RESULTS

Of 120 subjects enrolled, 78 (SC, N = 41; MuGard, N = 37) were eligible for efficacy analysis. Both cohorts were similar in demographics, baseline characteristics, primary tumor type, and planned CRT regimen. MuGard effectively mitigated OM symptoms as reflected by area under the curve of daily patient‐reported oral soreness (P = .034) and WHO scores on the last day of radiation therapy (P = .038). MuGard was also associated with nonsignificant trends related to therapeutic benefit including opioid use duration, and OM scores (WHO criteria) at CRT week 4. Rinse compliance was identical between cohorts. No significant adverse events were reported, and the adverse event incidence was similar between cohorts.

CONCLUSIONS

Testing MuGard, a rinse marketed as a device, in a standard clinical trial format demonstrated its superiority to SC in mitigating OM symptoms, delaying OM progression, and its safety and tolerability. Cancer 2014;120:1433–1440. © 2014 Access Pharmaceuticals, Inc. Cancer published by Wiley Periodicals. Inc. on behalf of American Cancer Society.

In a randomized, double‐blind, placebo‐controlled trial, the mucoadhesive hydrogel MuGard proved to be superior to saline‐bicarbonate rinse in mitigating oral mucositis (OM) symptoms and delaying OM progression. MuGard was safe and well‐tolerated, and favorably affected the rate and incidence of ulcerative lesions, consistent with the patient‐reported outcomes.