Cisplatin upregulates glutamine transport in human intestinal epithelial cells: the protective mechanism of glutamine on intestinal mucosa after chemotherapy

Potential Drug-Nutrient Interactions of 45 Vitamins, Minerals, Trace Elements, and Associated Dietary Compounds with Acetylsalicylic Acid and Warfarin-A Review of the Literature

In cardiology, acetylsalicylic acid (ASA) and warfarin are among the most commonly used prophylactic therapies against thromboembolic events. Drug-drug interactions are generally well-known. Less known are the drug-nutrient interactions (DNIs), impeding drug absorption and altering micronutritional status. ASA and warfarin might influence the micronutritional status of patients through different mechanisms such as binding or modification of binding properties of ligands, absorption, transport, cellular use or concentration, or excretion. Our article reviews the drug-nutrient interactions that alter micronutritional status. Some of these mechanisms could be investigated with the aim to potentiate the drug effects. DNIs are seen occasionally in ASA and warfarin and could be managed through simple strategies such as risk stratification of DNIs on an individual patient basis; micronutritional status assessment as part of the medical history; extensive use of the drug-interaction probability scale to reference little-known interactions, and application of a personal, predictive, and preventive medical model using omics.

L-Glutamine and Survival of Patients with Locally Advanced Head and Neck Cancer Receiving Chemoradiotherapy

We previously reported that L-glutamine reduces the severity of mucositis caused by chemoradiotherapy in patients with head and neck cancer. However, the impact of glutamine on the anti-tumor effect of chemoradiotherapy remains controversial. This study, which included 40 patients, investigated whether L-glutamine influences survival. Radiation therapy (total: 66 or 70 Gy), cisplatin, and docetaxel were co-administered for a period of 6 weeks. Patients were randomly assigned to receive either glutamine (glutamine group, n = 20) or placebo (placebo group, n = 20) during the entire course of chemoradiotherapy. We compared the overall survival and progression-free survival rates between the two groups. At 5-year follow-up, 16 (80%) and 13 (72%) patients in the glutamine and placebo groups, respectively, survived (with no significant difference in overall survival [glutamine group: 55.2 ± 12.7 months vs. placebo group: 48.3 ± 21.3 months]). A total of 14 (70%) and 12 (67%) patients in the glutamine and placebo groups, respectively, did not experience disease progression (with no significant difference in progression-free survival [glutamine group: 46.7 ± 19.5 months vs. placebo group: 43.6 ± 25.2 months]). These findings indicate that L-glutamine does not influence the survival of patients with locally advanced head and neck cancer receiving chemoradiotherapy.

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

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

Dietary Supplementation with Monosodium Glutamate Suppresses Chemotherapy-Induced Downregulation of the T1R3 Taste Receptor Subunit in Head and Neck Cancer Patients

(Background) We investigated the effect of dietary supplementation with monosodium glutamate (MSG) on chemotherapy-induced downregulation of the T1R3 taste receptor subunit expression in the tongue of patients with advanced head and neck cancer. (Methods) Patients undergoing two rounds of chemoradiotherapy were randomly allocated to a control or intervention group (dietary supplementation with MSG at 2.7 g/day during the second round of chemotherapy). The relative expression of T1R3, a subunit of both umami and sweet taste receptors, in the tongue was assessed by quantitative polymerase chain reaction analysis. Dysgeusia was assessed with a visual analog scale and daily energy intake was evaluated. (Results) T1R3 expression levels in the tongue, taste sensitivity, and daily energy intake were significantly reduced after the first round of chemotherapy compared with before treatment. Furthermore, these parameters significantly decreased after the second round of chemotherapy, but the extent of decrease was significantly attenuated in the MSG group compared with the control group. (Conclusions) MSG supplementation suppresses chemotherapy-induced dysgeusia, possibly due to the inhibition of the T1R3-containing taste receptor downregulation in the tongue, thereby increasing energy intake in patients with advanced head and neck cancer.

Intake of Lactobacillus delbrueckii (pExu:hsp65) Prevents the Inflammation and the Disorganization of the Intestinal Mucosa in a Mouse Model of Mucositis

5-Fluorouracil (5-FU) is an antineoplastic drug that causes, as a side effect, intestinal mucositis, acute inflammation in the small bowel. The Heat Shock Protein (Hsp) are highly expressed in inflammatory conditions, developing an important role in immune modulation. Thus, they are potential candidates for the treatment of inflammatory diseases. In the mucositis mouse model, the present study aimed to evaluate the beneficial effect of oral administration of milk fermented by Lactobacillus delbrueckii CIDCA 133 (pExu:hsp65), a recombinant strain. This approach showed increased levels of sIgA in the intestinal fluid, reducing inflammatory infiltrate and intestinal permeability. Additionally, the histological score was improved. Protection was associated with a reduction in the gene expression of pro-inflammatory cytokines such as Tnf, Il6, Il12, and Il1b, and an increase in Il10, Muc2, and claudin 1 (Cldn1) and 2 (Cldn2) gene expression in ileum tissue. These findings are corroborated with the increased number of goblet cells, the electronic microscopy images, and the reduction of intestinal permeability. The administration of milk fermented by this recombinant probiotic strain was also able to reverse the high levels of gene expression of Tlrs caused by the 5-FU. Thus, the rCIDCA 133:Hsp65 strain was revealed to be a promising preventive strategy for small bowel inflammation.

A Randomized Controlled Trial to Evaluate the Role and Efficacy of Oral Glutamine in the Treatment of Chemo-radiotherapy-induced Oral Mucositis and Dysphagia in Patients with Oropharynx and Larynx Carcinoma

AIM

To determine the role and efficacy of oral glutamine in the treatment of chemo-radiotherapy-induced oral mucositis and dysphagia in patients with carcinoma of the oropharynx and larynx. The primary objective of this study was to compare the incidence and severity of oral mucositis and dysphagia between the glutamine group (oral glutamine, along with concurrent chemo-radiotherapy) and the control group (concurrent chemo-radiotherapy alone, no glutamine). Secondary objectives were to compare the time to onset of oral mucositis and dysphagia, the incidence of treatment breaks (more than three consecutive radiation fractions missed), and significant weight loss (more than 3 kilograms of weight loss from the baseline) between the two groups.

METHOD

A total of 60 patients with locally advanced carcinoma of the oropharynx and larynx (Stage III - IV) who were receiving concurrent chemo-radiotherapy were randomised to the glutamine group (study arm, n = 30) and the non-glutamine group (control arm, n = 30). All patients were treated by radiotherapy to a total dose of 70 Gy in 35 fractions, along with concurrent weekly injections of cisplatin (40 mg/m2) chemotherapy. Patients in the study arm received 10 gm of oral glutamine two hours before radiotherapy (five days a week during the seven-week course of radiotherapy). In the control arm, glutamine was not given to patients during the chemo-radiotherapy treatment. All patients were assessed for oral mucositis, dysphagia, weight loss, and compliance/gap in the treatment (greater than three consecutive days of radiation missed) until the completion of chemo-radiotherapy. Grading of oral mucositis and dysphagia was done as per the National Cancer Institute, Common Terminology Criteria for Adverse Events version 4.03.

RESULTS

Out of 60 patients, 56 patients (93.33%) completed the full course of chemo-radiotherapy treatment. Twenty-seven patients (96.43%) in the control arm developed Grade III oral mucositis compared to only 12 patients (42.83%) in the glutamine arm (p < 0.001). Twenty-six patients (93%) in the control arm developed Grade III dysphagia compared to only 11 patients (39%) in the glutamine arm (p < 0.001). Glutamine significantly decreased the incidence and severity of mucositis and dysphagia. Glutamine delayed the onset of mucositis and dysphagia. As severe dysphagia was more prevalent in the control arm, feeding by Ryle's tube was required in 17 patients (56.67%) in the control arm versus only in eight patients (26.67%) in the glutamine arm (p = 0.03). Significant weight loss during the treatment was seen in all patients of the control arm (100% patients) compared to only 71% of the patients in the glutamine arm (p = 0.004). In the control arm, 46.67% patients had treatment interruption (gap) compared to 16.67% in the glutamine arm (p = 0.025). Sixteen patients (53%) from the control arm required admission (inpatient care) in the hospital to manage the treatment-toxicity (mucositis and dysphagia) compared to seven patients (23%) from the glutamine arm (p = 0.03).

CONCLUSION

Glutamine significantly decreased the incidence and severity of chemo-radiotherapy-induced oral mucositis and dysphagia. It delayed the onset of oral mucositis and dysphagia, improved the compliance to the chemo-radiotherapy treatment, and reduced the requirement for hospitalization for the management of treatment-induced toxicities in patients with locally advanced carcinoma of the oropharynx and larynx.

The effect of glutamine and arginine-enriched nutritional support on quality of life in head and neck cancer patients treated with IMRT

BACKGROUND AND AIMS

Oral mucositis and esophagitis are common acute toxicities of radiotherapy (RT) for head and neck cancer (HNC). In order to decrease the rates of these toxicities, we compared quality of life in HNC patients that did and did not receive a glutamine and arginine-enriched solution (GAES) during RT.

METHODS

A total of 29 patients received intensity-modulated radiotherapy (IMRT); 15 used GAES b.i.d. during the treatment, and a matched cohort of 14 patients did not. Patients were administered the EORTC QLQ-C30, QLQ-H&N35 and QLQ-OES18 questionnaires on the 1st, 15th, and last days of IMRT.

RESULTS

The global health status, functional and symptom scale scores were similar in both groups on the 1st day of IMRT. On the 15th and last days, the scores of social functions (p = 0.01 and p = 0.012), pain (p = 0.002 and p = 0.002), appetite (p = 0.01 and p = 0.02), dry mouth (p = 0.001 and p = 0.03), sticky saliva (p = 0.003 and p = 0.04), trouble with taste (p = 0.001 and p = 0.03), trouble with social eating (p = 0.004 and p = 0.006), and swallowing problems (p = 0.002 and p = 0.046) were significantly worse in the control group.

CONCLUSIONS

Quality of life is negatively affected by IMRT; however, use of GAES may mediate this negative effect.

Is glutamine deficiency the link between inflammation, malnutrition, and fatigue in cancer patients?

PURPOSE

Evaluation of potential associations between plasma glutamine levels and the incidence of cancer related fatigue, physical performance, poor nutritional status, and inflammation in patients with solid tumors.

STUDY DESIGN

Mono-center cross-sectional study recruiting 100 (34 women) consecutive patients (September 2009-March 2011; ≥18 y) with solid tumors and causal tumor therapy.

METHODOLOGY

Fasting venous blood was harvested for routine clinical chemistry, amino acid (HPLC) and inflammation marker analyses. Clinical assessments included global, physical, affective and cognitive fatigue (questionnaire) and Karnofsky performance status. Nutritional status was evaluated using bioelectrical impedance analysis, the Prognostic Inflammatory and Nutritional Index and plasma protein levels. Regression analyses were performed to correlate continuous variables with plasma glutamine (95% confidence intervals).

RESULTS

Nutritional status was impaired in 19% of the patients. Average plasma glutamine concentration (574.0 ± 189.6 μmol/L) was within normal range but decreased with impaired physical function. Plasma glutamine was linked to the ratio extracellular to body cell mass (p < 0.044), CRP (p < 0.001), physical (p = 0.014), affective (p = 0.041), and global fatigue (p = 0.030). Markers of inflammation increased with low physical performance.

CONCLUSIONS

The data support our working hypothesis that in cancer patients systemic inflammation maintains a catabolic situation leading to malnutrition symptoms and glutamine deprivation, the latter being associated with cancer related fatigue.

L-glutamine decreases the severity of mucositis induced by chemoradiotherapy in patients with locally advanced head and neck cancer: a double-blind, randomized, placebo-controlled trial

The incidence of severe mucositis in the oral cavity, pharynx and larynx is high among patients with head and neck cancer (HNC) receiving chemoradiotherapy (CRT), resulting in significant pain and impairment of quality of life. The present study investigated whether L-glutamine (glutamine) decreases the severity of mucositis in the oral cavity, pharynx and larynx induced by CRT. This double-blind, randomized, placebo-controlled trial included 40 untreated patients with squamous cell carcinoma of the nasopharynx, oropharynx, hypopharynx or larynx. Patients received 66 or 70 Gy of total radiation at the rate of 2 Gy/fraction daily and 5 fractions/week. Cisplatin (20 mg/m²) and docetaxel (10 mg/m²) were intravenously co-administered once a week for 6 weeks. Patients were randomized to orally receive either glutamine (group G) or placebo (group P) at a dose of 10 g 3 times a day throughout the CRT course. Mucositis was assessed using the National Cancer Institute Common Terminology Criteria for Adverse Events version 3.0. The primary end point was mucositis severity. Mucositis developed in all patients. A maximal mucositis grade of G4 was observed in 0 and 25% group G and P patients, respectively, while that of G2 was observed in 10 and 0% group G and P patients, respectively (p=0.023). Glutamine significantly decreased the maximal mucositis grade (group G, 2.9±0.3; group P, 3.3±0.4; p=0.005) and pain score at weeks 4, 5 and 6. Glutamine significantly decreased mucositis severity in the oral cavity, pharynx and larynx induced by CRT in patients with HNC.

Molecular identification and cellular localization of a potential transport system involved in cystine/cysteine uptake in human lenses

In this study we have sought to identify whether cystine uptake mechanisms previously identified in the rat lens are also found in the human lens. Using a combination of reverse transcriptase PCR, Western blotting and immunohistochemistry, we show that the light chain subunit of the cystine/glutamate exchanger (XC-), xCT, and members of the glutamate transporter family (XAG) which include the Excitatory Amino Acid Transporter 4 (EAAT4) and the Alanine Serine Cysteine Transporter 2 (ASCT2) are all present at the transcript and protein level in human lenses. We demonstrate that in young lenses xCT, EAAT4 and ASCT2 are expressed in all regions indicating that a potential cystine uptake pathway similar to that found in the rat might also exist in human lenses. However, with increasing age, the immunolabeling for all transporters decreases, with no xCT labelling detected in the centre of old donor lenses. Our results show that XC- and EAAT4/ASCT2 may work together to mediate cystine uptake in the lens core of young human lenses. This suggests that the lens contains uptake mechanisms that are capable of accumulating cystine/cysteine in the lens centre where cysteine can be used as an antioxidant or cystine utilised as a source for protein-S-S-cysteine (PSSC) formation to buffer against oxidative stress. With increasing age, transporters in the lens core undergo age dependent post translational modifications. However, despite processing of these transporters with age, our results indicate that this cystine uptake pathway could account for the increased PSSC levels previously observed in the nucleus of older human lenses.

Solute carriers (SLCs) in cancer

During tumor progression cells acquire an altered metabolism, either as a cause or as a consequence of an increased need of energy and nutrients. All four major classes of macromolecules are affected: carbohydrates, proteins, lipids and nucleic acids. As a result of the changed needs, solute carriers (SLCs) which are the major transporters of these molecules are differently expressed. This renders them important targets in the treatment of cancer. Blocking or activating SLCs is one possible therapeutic strategy. For example, some SLCs are upregulated in tumor cells due to the increased demand for energy and nutritional needs. Thus, blocking them and turning off the delivery of fuel or nutrients could be one way to interfere with tumor progression. Specific drug delivery to cancer cells via transporters is another approach. Some SLCs are also interesting as chemosensitizing targets because blocking or activating them may result in an altered response to chemotherapy. In this review we summarize the roles of SLCs in cancer therapy and specifically their potential as direct or indirect targets, as drug carriers or as chemosensitizing targets.

Nutrition therapy issues in esophageal cancer

Esophageal cancer has traditionally been a disease with poor long term outcomes in terms of both survival and quality of life. In combination with surgical and pharmacologic therapy, nutrition support has been demonstrated to improve patient tolerance of treatment, quality of life, and longterm outcomes. An aggressive multi-disciplinary approach is warranted with nutrition support remaining a cornerstone in management. Historically, nutrition support has focused on adequate caloric provision to prevent weight loss and allow for tolerance of treatment regimens. Alterations in metabolism occur in these patients making their use of available calories inefficient and the future of nutritional support may lie in the ability to alter this deranged metabolism. The purpose of this article is to review the current literature surrounding the etiology, treatment, and role of nutrition support in improving outcomes in esophageal cancer.

Leptin regulates sugar and amino acids transport in the human intestinal cell line Caco-2

AIM

Studies in rodents have shown that leptin controls sugars and glutamine entry in the enterocytes by regulating membrane transporters. Here, we have examined the effect of leptin on sugar and amino acids absorption in the human model of intestinal cells Caco-2 and investigated the transporters involved.

METHODS

Substrate uptake experiments were performed in Caco-2 cells, grown on plates, in the presence and the absence of leptin, and the expression of the different transporters in brush border membrane vesicles was analysed by Western blot.

RESULTS

Leptin inhibited 0.1 mm α-methyl-D-glucoside uptake after 5 or 30 min treatment and decreased SGLT1 protein abundance in the apical membrane. Uptake of 20 μm glutamine and 0.1 mm phenylalanine was also inhibited by leptin, indicating sensitivity to the hormone of the Na(+) -dependent neutral amino acid transporters ASCT2 and B(0) AT1. This inhibition was accompanied by a reduction in the transporters expression at the brush border membrane. Leptin also inhibited 1 mm proline and β-alanine uptake in Na(+) medium at pH 6, conditions for optimal activity of the H(+) -dependent neutral amino acid transporter PAT1. In this case, abundance of PAT1 in the brush border membrane after leptin treatment was not modified. Interestingly, leptin inhibitory effect on β-alanine uptake was reversed by the PKA inhibitor H-89 suggesting involvement of PKA pathway in leptin's regulation of PAT1 activity.

CONCLUSION

These data show in human intestinal cells that leptin can rapidly control the activity of physiologically relevant transporters for rich-energy molecules, that is, D-glucose (SGLT1) and amino acids (ASCT2, B(0) AT1 and PAT1).

Glutamine prevents intestinal mucosal injury induced by cyclophosphamide in rats

PURPOSE

High doses of anticancer drugs often damage the intestinal mucosa. The purpose of the present study was to examine the effect of glutamine on mucosal damage induced by cyclophosphamide in a rat model, and to elucidate the mechanisms responsible for its protective effects.

METHOD

Rats were randomly assigned to one of the three experimental groups. Group A (control) (n = 8): intraperitoneal injection of saline, group B (n = 8): intraperitoneal injection of cyclophosphamide (300 mg/kg), group C (n = 8): intraperitoneal injection of cyclophosphamide (300 mg/kg) and oral glutamine (1.0 g/kg). After 3 days, the ileal segment was removed for morphological and the biochemical analyses. We also evaluated the level of mucosal apoptosis by the TUNEL method and enterocyte proliferation using bromodeoxyuridine (BrdU).

RESULTS

Mucosal atrophy was observed in group B but not in groups A or C. The mucosal wet weight, protein and glutathione levels were significantly decreased in group B compared with group A, and were increased significantly in group C compared with group B. While enterocyte proliferation significantly decreased and the apoptotic index significantly increased in group B compared with group A, a significant increase in the enterocyte proliferation and a significant decrease in apoptosis were observed in group C compared with group B.

CONCLUSIONS

Glutamine prevented intestinal mucosal injury induced by cyclophosphamide via increased glutathione, decreased apoptosis and increased proliferation of intestinal epithelial cells.

Drug-nutrient interactions: a broad view with implications for practice

The relevance of drug?nutrient interactions in daily practice continues to grow with the widespread use of medication. Interactions can involve a single nutrient, multiple nutrients, food in general, or nutrition status. Mechanistically, drug?nutrient interactions occur because of altered intestinal transport and metabolism, or systemic distribution, metabolism and excretion, as well as additive or antagonistic effects. Optimal patient care includes identifying, evaluating, and managing these interactions. This task can be supported by a systematic approach for categorizing interactions and rating their clinical significance. This review provides such a broad framework using recent examples, as well as some classic drug?nutrient interactions. Pertinent definitions are presented, as is a suggested approach for clinicians. This important and expanding subject will benefit tremendously from further clinician involvement.