Rosa laevigata Michx. Polysaccharide Ameliorates Diabetic Nephropathy in Mice through Inhibiting Ferroptosis and PI3K/AKT Pathway-Mediated Apoptosis and Modulating Tryptophan Metabolism.

Diabetic nephropathy (DN) is a metabolic disease wherein chronic hyperglycemia triggers various renal cell dysfunctions, eventually leading to progressive kidney failure. Rosa laevigata Michx. is a traditional Chinese herbal medicine. Many studies have confirmed its antioxidative, anti-inflammatory, and renoprotective effects. However, the effects and mechanisms of Rosa laevigata Michx. polysaccharide (RLP) in DN remain unclear. In this study, a DN mouse model was established to investigate the therapeutic effect of RLP on DN mice. Then, nontargeted metabolomics was used to analyze the potential mechanism of RLP in the treatment of DN. Finally, the effects of RLP on ferroptosis and the PI3K/AKT pathway were investigated. The results demonstrated that RLP effectively alleviated renal injury and reduced inflammation and oxidative stress in the kidney. In addition, nontargeted metabolomic analysis indicated that RLP could modulate riboflavin metabolism and tryptophan metabolism in DN mice. Notably, ferroptosis and PI3K/AKT pathway-mediated apoptosis in the kidney were also ameliorated following RLP treatment. In conclusion, this study confirmed that RLP had a significant therapeutic effect on DN mice. Furthermore, RLP treatment modulated tryptophan metabolism and inhibited ferroptosis and PI3K/AKT pathway-mediated apoptosis in the kidney.

Untargeted and Targeted Metabolomics Reveal the Active Peptide of Eupolyphaga sinensis Walker against Hyperlipidemia by Modulating Imbalance in Amino Acid Metabolism.

The active peptide (APE) of Eupolyphaga sinensis Walker, which is prepared by bioenzymatic digestion, has significant antihyperlipidemic effects in vivo, but its mechanism of action on hyperlipidemia is not clear. Recent studies on amino acid metabolism suggested a possible link between it and hyperlipidemia. In this study, we first characterized the composition of APE using various methods. Then, the therapeutic effects of APE on hyperlipidemic rats were evaluated, including lipid levels, the inflammatory response, and oxidative stress. Finally, the metabolism-regulating mechanisms of APE on hyperlipidemic rats were analyzed using untargeted and targeted metabolomic approaches. The results showed that APE significantly reduced the accumulation of fat, oxidative stress levels, and serum pro-inflammatory cytokine levels. Untargeted metabolomic analysis showed that the mechanism of the hypolipidemic effect of APE was mainly related to tryptophan metabolism, phenylalanine metabolism, arginine biosynthesis, and purine metabolism. Amino-acid-targeted metabolomic analysis showed that significant differences in the levels of eight amino acids occurred after APE treatment. Among them, the expression of tryptophan, alanine, glutamate, threonine, valine, and phenylalanine was upregulated, and that of arginine and proline was downregulated in APE-treated rats. In addition, APE significantly downregulated the mRNA expression of SREBP-1, SREBP-2, and HMGCR. Taking these points together, we hypothesize that APE ameliorates hyperlipidemia by modulating amino acid metabolism in the metabolome of the serum and feces, mediating the SREBP/HMGCR signaling pathway, and reducing oxidative stress and inflammation levels.

Integration of metabolomics and machine learning revealed tryptophan metabolites are sensitive biomarkers of pemetrexed efficacy in non-small cell lung cancer.

BACKGROUND: Anti-folate drug pemetrexed is a vital chemotherapy medication for non-small cell lung cancer (NSCLC). Its response varies widely and often develops resistance to the treatment. Therefore, it is urgent to identify biomarkers and establish models for drug efficacy evaluation and prediction for rational drug use. METHODS: A total of 360 subjects were screened and 323 subjects were recruited. Using metabolomics in combination with machine learning methods, we are trying to select potential biomarkers to diagnose NSCLC and evaluate the efficacy of pemetrexed in treating NSCLC. Furtherly, we measured the concentration of eight metabolites in the tryptophan metabolism pathway in the validation set containing 201 subjects using a targeted metabolomics method with UPLC-MS/MS. RESULTS: In the discovery set containing 122 subjects, the metabolic profile of healthy controls (H), newly diagnosed NSCLC patients (ND), patients who responded well to pemetrexed treatment (S) and pemetrexed-resistant patients (R) differed significantly on the PLS-DA scores plot. Pathway analysis showed that glycine, serine and threonine metabolism occurred in every two group comparisons. TCA cycle, pyruvate metabolism and glycerolipid metabolism are the most significantly changed pathways between ND and H group, pyruvate metabolism was the most altered pathway between S and ND group, and tryptophan metabolism was the most changed pathway between S and R group. We found Random forest method had the maximum area under the curve (AUC) and can be easily interpreted. The AUC is 0.981 for diagnosing patients with NSCLC and 0.954 for evaluating pemetrexed efficiency. CONCLUSION: We compared eight mathematical models to evaluate pemetrexed efficiency for treating NSCLC. The Random forest model established with metabolic markers tryptophan, kynurenine and xanthurenic acidcan accurately diagnose NSCLC and evaluate the response of pemetrexed.

The role of cytokines and Indolamine-2.3 dioxygenase in experiencing a psycho-neurological symptom cluster in hematological cancer patients: IL-1alpha, IL-1beta, IL-4, IL-6, TNF-alpha, kynurenine, and tryptophan.

OBJECTIVE: This study examined (a) whether there are a subgroup of cancer patients experiencing the selected psycho-neurological symptoms as a cluster (depression, cognitive impairment, fatigue, sleep disturbance, and pain); (b) whether demographic and clinical characteristics and pro-inflammatory cytokines (IL-1α, IL-1ß, IL-4, IL-6, TNF-alpha) are associated with subgroup membership; and (c) whether the activity of indolamine-2.3 dioxygenase(IDO) is associated with pro-inflammatory cytokine activity and psycho-neurological symptom cluster experience. METHODS: This was a prospective cohort study where 149 hematologic patients were recruited from a university hospital and 65 healthy volunteers provided control data. Latent profile analyses were conducted to identify subgroups at two time points: the last day of chemotherapy and 1 week after chemotherapy completion. Influencing factors of subgroup membership were examined by logistic regression. RESULTS: A substantial number of patients (33%, 34% at each time point) experienced the selected psycho-neurological symptoms as a cluster. Older age and elevated IL-1α and IL-6 were associated with experiencing the psycho-neurological symptom cluster. IDO activity was higher in the patients experiencing psycho-neurological symptom cluster; and was positively associated with IL-6. Symptom severity, IL-1α, IL-6, and IDO activity were all significantly higher in cancer patients than in the healthy controls. The findings were preserved across time points. CONCLUSIONS: The activation of pro-inflammatory cytokines and their cross-talk with IDO may be a common biological mechanism, underlying a psycho-neurological symptom cluster experience. The novel approaches for symptom assessment and management can be developed by assessing multiple psycho-neurological symptoms as a cluster and by targeting their common biological pathway.

[Repair stimulator alpha-glutamyl-tryptophan in the complex therapy of chronic atrophic gastritis: results of histological examination]. / Stimulyator reparatsii al'fa-glutamil-triptofan v kompleksnoi terapii khronicheskogo atroficheskogo gastrita: rezul'taty gistologicheskogo issledovaniya.

OBJECTIVE: To study the effect of the repair stimulator alpha-glutamyl-tryptophan on the morphological characteristics of the gastric mucosa and the expression of CXCL-12 and CDX-2 in chronic atrophic gastritis associated with Helicobacter pylori. MATERIAL AND METHODS: Biopsy samples of 116 patients with a verified diagnosis of chronic atrophic gastritis associated with Helicobacter pylori were analyzed in a multicenter double-blind randomized placebo-controlled study. During the morphological study, the parameters characterizing the process of atrophy were evaluated: the number of glands per 1 mm2 of the gastric mucosa, the depth of the gastric mucosa glands, the number of parietal cells per 100 epithelial cells of the gastric mucosa, and the presence of signs of intestinal metaplasia. Primary antibodies Anti-CXCL-12 (MA5-23759) and Anti-CDX-2 (EP25) were used to set up immunohistochemical reactions to verify the expression of CXCL-12 and CDX-2. RESULTS: In patients taking the studied drug, a statistically significant increase in the number of glands per 1 mm2 of the gastric mucosa was revealed when compared with the initial screening indicators by 26.1% (p=0.028) and with the placebo group (p=0.026), a tendency to decrease the signs of intestinal metaplasia was determined. There was a statistically significant increase in the expression in the relative area of CXCL-12 expression in patients taking placebo when compared with the parameters of the initial data (p=0.045) and the absence of statistically significant changes in the main group. A statistically significant increase in the relative area of the CDX-2 expression was revealed in the group taking alpha-glutamyl-tryptophan in comparison with the baseline data (p=0.015), no statistically significant dynamics of this indicator was found in the placebo group. CONCLUSION: A statistically significant positive effect of the study drug on regenerative mechanisms leading to stabilization and/or improvement of the histological picture in the atrophic area of the gastric mucosa was found in comparison with the control of the initial state and with placebo. The results of an immunohistochemical study to increase CDX-2 expression while taking the study drug can also be regarded as an indicator of improvement in reparative processes.

Expression of Tryptophan Metabolism Enzymes in Patients with Diffuse Large B-cell Lymphoma and NK/T-cell Lymphoma.

BACKGROUND: Metabolites of tryptophan (Trp) metabolism in the tumor microenvironment play crucial immunosuppressive roles in various cancers. However, the role of Trp metabolism in diffuse large B-cell lymphoma (DLBCL) or natural killer/T-cell lymphoma (NK/TCL) remains unelucidated. METHODS: We investigated the potential role of Trp metabolism in a cohort of 43 patients with DLBCL and 23 with NK/TCL. We constructed tissue microarrays and performed in situ staining of Trp-catabolizing enzymes and PD-L1 using immunohistochemistry (IHC). RESULTS: We observed 14.0% positive staining of IDO1 in DCBCL and 60.9% in NK/TCL; 55.8% of IDO2 in DCBCL and 95.7% in NK/TCL; 79.1% of TDO2 in DCBCL and 43.5% in NK/TCL; 29.7% of IL4I1 in DCBCL and 39.1% in NK/TCL. However, IDO1, IDO2, TDO2, and IL4I1 positivity did not significantly differ between PD-L1+ and PD-L1- biopsy tissue samples of NK/TCL; nonetheless, a positive correlation of IDO1 (r = 0.87, p < 0.001), IDO2 (r = 0.70, p < 0.001), TDO2 (r = 0.63, p < 0.001), and IL4I1 (r = 0.53, p < 0.05) with PD-L1 expression was observed in the TCGA-DLBCL dataset. Finally, immunohistochemical (IHC) analysis revealed the lack of superior prognostic effect with higher expression of Trp enzymes in DLBCL and NK/TCL. Furthermore, IDO1, IDO2, TDO2, and IL4I1 expression, as well as survival rates, did not significantly differ across all groups in the TCGA-DLBCL cohort. CONCLUSION: Collectively, our findings provide novel insights into the enzymes involved in Trp metabolism in DLBCL and NK/TCL and their association with PD-L1 expression, which offers potential strategies to combine Trp-metabolism enzyme inhibitors with anti-PD-L1 or other immunotherapeutic strategies in clinical DLBCL or NK/TCL treatment.

Microbiota-derived 3-IAA influences chemotherapy efficacy in pancreatic cancer.

Pancreatic ductal adenocarcinoma (PDAC) is expected to be the second most deadly cancer by 2040, owing to the high incidence of metastatic disease and limited responses to treatment1,2. Less than half of all patients respond to the primary treatment for PDAC, chemotherapy3,4, and genetic alterations alone cannot explain this5. Diet is an environmental factor that can influence the response to therapies, but its role in PDAC is unclear. Here, using shotgun metagenomic sequencing and metabolomic screening, we show that the microbiota-derived tryptophan metabolite indole-3-acetic acid (3-IAA) is enriched in patients who respond to treatment. Faecal microbiota transplantation, short-term dietary manipulation of tryptophan and oral 3-IAA administration increase the efficacy of chemotherapy in humanized gnotobiotic mouse models of PDAC. Using a combination of loss- and gain-of-function experiments, we show that the efficacy of 3-IAA and chemotherapy is licensed by neutrophil-derived myeloperoxidase. Myeloperoxidase oxidizes 3-IAA, which in combination with chemotherapy induces a downregulation of the reactive oxygen species (ROS)-degrading enzymes glutathione peroxidase 3 and glutathione peroxidase 7. All of this results in the accumulation of ROS and the downregulation of autophagy in cancer cells, which compromises their metabolic fitness and, ultimately, their proliferation. In humans, we observed a significant correlation between the levels of 3-IAA and the efficacy of therapy in two independent PDAC cohorts. In summary, we identify a microbiota-derived metabolite that has clinical implications in the treatment of PDAC, and provide a motivation for considering nutritional interventions during the treatment of patients with cancer.

Expression of PD-L1 and YWHAZ in Patients with Diffuse Large B Cell Lymphoma: A Possible Association with the Prognosis of Lymphoma.

Diffuse large B cell lymphoma (DLBCL) is the most common pathological subtype of non-Hodgkin lymphoma (NHL) and is the most common type of adult lymphoma. Due to the poor prognosis of relapsed/refractory DLBCL, new drug targets and therapeutic methods are urgently needed. We investigated the expression of programmed death ligand 1 (PD-L1) and 3-monooxygenase/tryptophan 5-monooxygenase activating protein zeta (14-3-3ζ or YWHAZ) in patients with DLBCL. The purpose was to verify the expression levels of YWHAZ and PD-L1 and their relationships with the prognosis of DLBCL and to lay a foundation for further study on the role of YWHAZ and PD-L1 in DLBCL. Immunohistochemistry was used in 140 patients with DLBCL to test protein expression levels of YWHAZ and PD-L1. All patients were followed up in the hospital or by telephone or via WeChat. The positive expression rate of YWHAZ was 62.14% (87/140). The expression was negatively correlated with the positive expression of BAD (r = -0.177, P = 0.036) and positively correlated with the positive expression of BCL-2 (r = 0.180, P = 0.033). When the cut-off value for PD-L1 was established at 5%, 10%, 15%, and 20%, the corresponding positive expression rates of PD-L1 were 79.66% (94/118), 51.69% (61/118), 40.68% (48/118), and 36.44% (43/118). YWHAZ significantly affected the OS of DLBCL (P ≤ 0.001). The prognosis of the patients was related to the positive expression of PD-L1 when the cut-off value of PD-L1 was 5% (P = 0.033). However, positive expression of PD-L1 was not associated with the prognosis when the cut-off values of PD-L1 were 10% (P = 0.404), 15% (P = 0.208), and 20% (P = 0.408). The positive expression of YWHAZ (hazard ratio 6.215; 95% confidence interval 3.214-12.017; P < 0.05) was an independent adverse prognostic factor for OS. YWHAZ may be an important oncogene in the occurrence and development of DLBCL and may be used as a therapeutic target. PD-L1 may be an oncogene or tumor suppressor gene in the occurrence and development of DLBCL. Different cut-off values of PD-L1 may affect the prognosis of DLBCL.

Potential role of tryptophan catabolism in cancer-related cognitive impairment.

Oncology may be the most rapidly expanding field in medicine, with several innovative diagnostic and therapeutic procedures appearing daily. Advances in oncology have improved the survival rate for patients with cancer and promoting quality of life is now one of the goals in the care of these patients. Patients face a variety of disease- and treatment-related side effects, including anorexia, nausea, vomiting, recurring infections, and sleep difficulties. Cancer-related cognitive impairment (CRCI) is an overlooked clinical condition found in oncologic practice, particularly in patients with breast cancer. Although several potential mechanisms for CRCI have been hypothesized, to our knowledge, the exact mechanism is still unknown. Alterations in the tryptophan kynurenine pathway have been shown to impair cognitive skills in several mental illnesses. However, its possible function in CRCI has yet to be investigated. The aim of this was to examine the possible interactions between tryptophan catabolism and CRCI.

Synthesis of smart carriers based on tryptophan-functionalized magnetic nanoparticles and its application in 5-fluorouracil delivery.

Multifunctional nanocarriers, specifically for tumor targeting and traceable features, have been increasingly considered in cancer therapies. Herein, a novel targeting agent (TA), tryptophan (TRP), was proposed for the synthesis of functionalized (3-aminopropyl) triethoxysilane-iron oxide nanoparticles using two methods, creating a smart drug delivery system (DDS). In one method, two-step, glutaraldehyde (GA) as a linker, bonded TRP and amino-functionalized magnetite, and in the second method, one step, TRP binding was carried out by (3-dimethyl aminopropyl)-N'-ethyl carbodiimide hydrochloride (EDC)/N-hydroxysuccinimide ester. The synthesis yield of the second method was 7% higher than the first method. After synthesizing DDS, 5-fluorouracil (5-FU) was loaded on nanocarriers and was observed TRP functionalized nanoparticles by GA have better loading efficiency, which was 50% greater than the product from the one-step method. A pH-sensitive release profile was also studied for 5-FU/DDS with the release of almost 75% and 50% at pH 5.5 and 7.4, respectively. To analyze the biological aspects of nanocarriers, human breast cancer, MCF-7, and embryonic kidney, HEK293, cell lines were used for cellular uptake and 3-(4, 5-dimethylthiazol-2-yl)-2, 5-diphenyltetrazolium bromide (MTT) assays.In vitrostudies confirmed that TRP can act as a TA as its cellular uptake through cancerous cells was 40% greater than normal cells, and the MTT assay confirmed that using DDS can increase and decrease the cell viability of normal cells and cancerous cells, respectively, compared to free drug. Therefore, it was concluded that advanced nano-assembly is a great candidate for breast cancer cell-targeted delivery.

Tryptophan metabolites modulate inflammatory bowel disease and colorectal cancer by affecting immune system.

Tryptophan is an essential amino acid, going through three different metabolic pathways in the intestines. Indole pathway in the gut microbiota, serotonin system in the enterochromaffin cells and kynurenine pathway in the immune cells and intestinal lining are the three arms of tryptophan metabolism in the intestines. Clinical, in vivo and in vitro studies showed that each one of these arms has a significant impact on IBD. This review explains how different metabolites of tryptophan are involved in the pathophysiology of IBD and colorectal cancer, as a major complication of IBD. Indole metabolites alleviate colitis and protect against colorectal cancer while serotonin arm follows a more complicated and receptor-specific pattern. Indole metabolites and kynurenine interact with aryl hydrocarbon receptor (AHR) to induce T regulatory cells differentiation, confine Th17 and Th1 response and produce anti-inflammatory mediators. Kynurenine decreases tumor-infiltrating CD8+ cells and mediates tumor cells immune evasion. Serotonin system also increases colorectal cancer cells proliferation and metastasis while, indole metabolites can profoundly decrease colorectal cancer growth. Targeted therapy for tryptophan metabolites may improve the management of IBD and colorectal cancer, e.g. supplementation of indole metabolites such as indole-3-carbinol (I3C), inhibition of kynurenine monooxygenase (KMO) and selective stimulation or inhibition of specific serotonergic receptors can mitigate colitis. Furthermore, it will be explained how indole metabolites supplementation, inhibition of indoleamine 2,3-dioxygenase 1 (IDO1), KMO and serotonin receptors can protect against colorectal cancer. Additionally, extensive molecular interactions between tryptophan metabolites and intracellular signaling pathways will be thoroughly discussed.

D-MT prompts the anti-tumor effect of oxaliplatin by inhibiting IDO expression in a mouse model of colon cancer.

Colon cancer is one of the most common malignant tumors in the digestive system. Although oxaliplatin, a chemotherapy drug, has been clinically used to treat colon cancer, its therapeutic effect is unsatisfactory. It has been proved that indoleamine dioxygenase 2,3 (IDO) is a tumor immunosuppressive factor for the immune response. Herein, an IDO inhibitor, D-MT (indoximod, 1-Methyl-D-tryptophan), was combined with oxaliplatin to treat colon cancer in mice. T cell infiltration in tumor tissues, the ratios of immune cells in the spleens, and the tumor growth and survival of the mice were detected and recorded. The results showed that the combination of oxaliplatin and D-MT significantly inhibited tumor growth and prolonged the survival of tumor-bearing mice. More importantly, the combination treatment increased the ratios of CD4+ T, CD8+ T and NK cells from the spleen in tumor-bearing mice, and prompted T cell infiltration in tumor tissues. This study provided a new therapeutic strategy for colon cancer treatment in the clinic, especially for patients with oxaliplatin resistance.

Injectable Micelle-Incorporated Hydrogels for the Localized Chemo-Immunotherapy of Breast Tumors.

Although immune checkpoint blockade (ICB) holds potential for the treatment of various tumors, a considerable proportion of patients show a limited response to ICB therapy due to the low immunogenicity of a variety of tumors. It has been shown that some chemotherapeutics can turn low-immunogenic tumors into immunogenic phenotypes by inducing a cascade of immune responses. In this paper, we synthesized an injectable micelle-incorporated hydrogel, which was able to sequentially release the chemotherapeutic gemcitabine (GEM) and the hydrophobic indoleamine 2, 3-dioxygenase inhibitor, d-1-methyltryptophan (d-1MT) at tumor sites. The hydrogel was formed via the thiol-ene click reaction between the thiolated chondroitin sulfate and the micelle formed by amphiphilic methacrylated Pluronic F127, in which hydrophobic d-1MT was encapsulated in the core of the F127 micelles and the hydrophilic GEM was dispersed in the hydrogel network. The successive release of chemotherapeutics and immune checkpoint inhibitors at tumor tissues will first promote the infiltration of cytotoxic T lymphocytes and subsequently induce a robust antitumor immune response, ultimately exerting a synergetic therapeutic efficacy. In a 4T1 tumor-bearing mice model, our results showed that the combination of chemotherapy and immunotherapy through the micelle-incorporated hydrogel triggered an effective antitumor immune response and inhibited tumor metastasis to the lung. Our results highlight the potential of the injectable micelle-incorporated hydrogel for the localized chemo-immunotherapy in the treatment of breast tumors.

Tryptophan potentiates CD8+ T cells against cancer cells by TRIP12 tryptophanylation and surface PD-1 downregulation.

BACKGROUND: Tryptophan catabolites suppress immunity. Therefore, blocking tryptophan catabolism with indoleamine 2,3-dioxygenase (IDO) inhibitors is pursued as an anticancer strategy. METHODS: The intracellular level of tryptophan and kynurenine was detected by mass spectrum analysis. The effect of tryptophan and IDO inhibitors on cell surface programmed cell death protein 1 (PD-1) level were measured by flow cytometry. A set of biochemical analyses were used to figure out the underlying mechanism. In vitro co-culture system, syngeneic mouse models, immunofluorescent staining, and flow cytometry analysis were employed to investigate the role of tryptophan and IDO inhibitor in regulating the cytotoxicity of CD8+ T cells. RESULTS: Here, we reported that IDO inhibitors activated CD8+ T cells also by accumulating tryptophan that downregulated PD-1. Tryptophan and IDO inhibitors administration, both increased intracellular tryptophan, and tryptophanyl-tRNA synthetase (WARS) overexpression decreased Jurkat and mice CD8+ T cell surface PD-1. Mechanistically, WARS tryptophanylated lysine 1136 of and activated E3 ligase TRIP12 to degrade NFATc1, a PD-1 transcription activator. SIRT1 de-tryptophanylated TRIP12 and reversed the effects of tryptophan and WARS on PD-1. Tryptophan or IDO inhibitors potentiated CD8+ T cells to induce apoptosis of co-cultured cancer cells, increased cancer-infiltrating CD8+ T cells and slowed down tumor growth of lung cancer in mice. CONCLUSIONS: Our results revealed the immune-activating efficacy of tryptophan, and suggested tryptophan supplemental may benefit IDO inhibitors and PD-1 blockade during anticancer treatments.

STING agonist and IDO inhibitor combination therapy inhibits tumor progression in murine models of colorectal cancer.

Despite impressive clinical success, cancer immunotherapy based on immune checkpoint blockade remains ineffective in colorectal cancer (CRC). Stimulator of interferon genes (STING) is a novel potential target and STING agonists have shown potential anti-tumor efficacy. Combined therapy based on synergistic mechanism can overcome the resistance. However, STING agonists-based combination therapies are deficient. We designed different immunotherapy combinations, including STING agonist, indoleamine 2,3 dioxygenase (IDO) inhibitor and PD-1 blockade, with purpose of exploring which option can effectively inhibit CRC growth. To further explore the possible reasons of therapeutic effectiveness, we observed the combination therapy in C57BL/6Tmem173gt mice. Our findings demonstrated that STING agonist diABZI combined with IDO inhibitor 1-MT significantly inhibited tumor growth, even better than the three-drug combination, promoted the recruitment of CD8+ T cells and dendritic cells, and decreased the infiltration of myeloid-derived suppressor cells. We conclude that diABZI combined with 1-MT is a promising option for CRC.

Phase II trial of the IDO pathway inhibitor indoximod plus pembrolizumab for the treatment of patients with advanced melanoma.

BACKGROUND: The indoleamine 2,3-dioxygenase (IDO) pathway is a key counter-regulatory mechanism that, in cancer, is exploited by tumors to evade antitumor immunity. Indoximod is a small-molecule IDO pathway inhibitor that reverses the immunosuppressive effects of low tryptophan (Trp) and high kynurenine (Kyn) that result from IDO activity. In this study, indoximod was used in combination with a checkpoint inhibitor (CPI) pembrolizumab for the treatment for advanced melanoma. METHODS: Patients with advanced melanoma were enrolled in a single-arm phase II clinical trial evaluating the addition of indoximod to standard of care CPI approved for melanoma. Investigators administered their choice of CPI including pembrolizumab (P), nivolumab (N), or ipilimumab (I). Indoximod was administered continuously (1200 mg orally two times per day), with concurrent CPI dosed per US Food and Drug Administration (FDA)-approved label. RESULTS: Between July 2014 and July 2017, 131 patients were enrolled. (P) was used more frequently (n=114, 87%) per investigator's choice. The efficacy evaluable population consisted of 89 patients from the phase II cohort with non-ocular melanoma who received indoximod combined with (P).The objective response rate (ORR) for the evaluable population was 51% with confirmed complete response of 20% and disease control rate of 70%. Median progression-free survival was 12.4 months (95% CI 6.4 to 24.9). The ORR for Programmed Death-Ligand 1 (PD-L1)-positive patients was 70% compared with 46% for PD-L1-negative patients. The combination was well tolerated, and side effects were similar to what was expected from single agent (P). CONCLUSION: In this study, the combination of indoximod and (P) was well tolerated and showed antitumor efficacy that is worth further evaluation in selected patients with advanced melanoma.

Targeting SERT promotes tryptophan metabolism: mechanisms and implications in colon cancer treatment.

BACKGROUND: Serotonin signaling has been associated with tumorigenesis and tumor progression. Targeting the serotonin transporter to block serotonin cellular uptake confers antineoplastic effects in various tumors, including colon cancer. However, the antineoplastic mechanism of serotonin transporter inhibition and serotonin metabolism alterations in the absence of serotonin transporter have not been elucidated, especially in colon cancer, which might limit anti-tumor effects associating with targeting serotonin transporter. METHODS: The promotion in the uptake and catabolism of extracellular tryptophan and targeting serotonin transporter was detected by using quantitative reverse-transcription polymerase chain reaction, western blotting and liquid chromatography tandem mass spectrometry. Western blotting Immunoprecipitation and immunofluorescence was utilized to research the serotonylation of mTOR by serotonin and serotonin transporter inhibition. The primary mouse model, homograft model and tissue microarry was used to explore the tryptophan pathway in colon cancer. The cell viability assay, western blotting, xenograft and primary colon cancer mouse model were used to identify whether the combination of sertraline and tryptophan restriction had a synergistic effect. RESULTS: Targeting serotonin transporter through genetic ablation or pharmacological inhibition in vitro and in vivo induced a compensatory effect by promoting the uptake and catabolism of extracellular tryptophan in colon cancer. Mechanistically, targeting serotonin transporter suppressed mTOR serotonylation, leading to mTOR inactivation and increased tryptophan uptake. In turn, this process promoted serotonin biosynthesis and oncogenic metabolite kynurenine production through enhanced tryptophan catabolism. Tryptophan deprivation, or blocking its uptake by using trametinib, a MEK inhibitor, can sensitize colon cancer to selective serotonin reuptake inhibitors. CONCLUSIONS: The present study elucidated a novel feedback mechanism involved in the regulation of serotonin homeostasis and suggested innovative strategies for selective serotonin reuptake inhibitors-based treatment of colon cancer.

[L-tryptophan as dietetic supplement and treatment for hot flashes, astenia, and insomnia in cancer patients]. / Triptófano como suplemento dietético y tratamiento de los sofocos, la astenia y el insomnio en el cáncer.

INTRODUCTION: Introduction: in women with breast cancer and gynecologic cancer, as well as in men with prostate carcinoma, hot flashes, asthenia, and insomnia are common and bothersome symptoms that impair quality of life. Objective: to evaluate the effectiveness of tryptophan intake as a treatment for hot flushes, asthenia, and insomnia in patients with prostate, breast, and uterine cervical cancer. Materials and methods: intervention study without a control group at the HUCA Radiation Oncology Service, from July 2018 to July 2019. A total of 60 patients with prostate, breast, or uterine cervical cancer who had received treatment with radiotherapy and hormone therapy, and who presented with hot flushes, asthenia, and insomnia were included. L-tryptophan was administered at a dose of 3 g per day. Results: a significant increase in serum tryptophan levels at the end of the study (p < 0.001) and a significant decrease in the scores of the study symptoms were reported. Although statistical significance was not found, a significant improvement in each symptom was observed, as well as an improvement in quality of life (p < 0.001). Conclusions: the study suggests that, in patients with breast, prostate, or uterine cervical cancer, and symptoms such as hot flushes, asthenia, and insomnia, the administration of tryptophan as a nutritional supplement is well tolerated, improves quality of life, and is associated with improvement in the scale scores of the symptoms of interest, although no statistically significant relationship with increased blood tryptophan levels was found.

INTRODUCCIÓN: Introducción: tanto en las mujeres con cáncer de mama y cáncer ginecológico como en los hombres con carcinoma prostático, los sofocos, la astenia y el insomnio son síntomas frecuentes y molestos que alteran la calidad de vida. Objetivo: evaluar la eficacia del aporte de triptófano como tratamiento de los sofocos, la astenia y el insomnio en pacientes con cáncer de próstata, de mama y cervicouterino. Materiales y métodos: estudio de intervención sin grupo de control en el Servicio de Oncología Radioterápica del HUCA, en el período de julio de 2018 a julio de 2019. Se incluyeron en total 60 pacientes con cáncer de próstata, de mama y cervicouterino que habían recibido tratamiento con radioterapia y hormonoterapia, y que presentaban sofocos, astenia e insomnio. Se administraron 3 g de L-triptófano al día. Resultados: se reportan un aumento significativo del valor del triptófano sérico al final del estudio (p < 0,001) y una disminución significativa de las puntuaciones de los síntomas estudiados; aunque no hemos hallado ninguna significación estadística entre ellos, sí se aprecia una mejoría significativa de cada uno de los síntomas, así como una mejoría de la calidad de vida (p < 0,001). Conclusiones: el estudio actual sugiere que, en los pacientes con cáncer de mama, de próstata o cervicouterino y síntomas de sofocos, astenia e insomnio, el aporte de triptófano como suplemento nutricional se tolera bien, mejora la calidad de vida y puede asociarse a una mejoría de los valores obtenidos en las escalas de los síntomas referidos, aunque no se demuestra ninguna relación estadísticamente significativa con la elevación del triptófano en sangre.

5-methoxytryptophan alleviates liver fibrosis by modulating FOXO3a/miR-21/ATG5 signaling pathway mediated autophagy.

Liver fibrosis is a critical health issue in the world due to its rapidly increasing prevalence. It is of great demand to develop effective drugs for the treatment of liver fibrosis. 5-methoxytryptophan (5-MTP) has been reported to play an important role in anti-inflammatory, anti-cancer, myocardial-protective effects. However, the anti-fibrotic effect of 5-MTP is never covered in liver. Here, we investigated anti-fibrotic effects of 5-MTP on liver fibrosis and its underlying mechanism. In vitro, 5-MTP treatment could inhibit TGF-ß1-induced elevated levels of collagen I, collagen III, fibronectin and α-smooth muscle actin (SMA) by stimulating autophagy process. Mechanically, the expression of FOXO3a was enhanced by 5-MTP and then repressed the level of miR-21, eventually leading to a restoration of autophagy-related gene ATG5. Furthermore, rescue experiments showed 5-MTP could activate autophagy process and suppress the activation of LX-2 cells by regulating FOXO3a/miR-21/ATG5 pathway. Consistently, 5-MTP significantly attenuated CCl4-induced hepatic fibrosis in rat model. In conclusion, our research discovered that 5-MTP effectively alleviated liver fibrosis in vitro and in vivo, which provided new insights into the application of 5-MTP for liver fibrosis.

Tryptophan metabolism drives dynamic immunosuppressive myeloid states in IDH-mutant gliomas.

The dynamics and phenotypes of intratumoral myeloid cells during tumor progression are poorly understood. Here we define myeloid cellular states in gliomas by longitudinal single-cell profiling and demonstrate their strict control by the tumor genotype: in isocitrate dehydrogenase (IDH)-mutant tumors, differentiation of infiltrating myeloid cells is blocked, resulting in an immature phenotype. In late-stage gliomas, monocyte-derived macrophages drive tolerogenic alignment of the microenvironment, thus preventing T cell response. We define the IDH-dependent tumor education of infiltrating macrophages to be causally related to a complex re-orchestration of tryptophan metabolism, resulting in activation of the aryl hydrocarbon receptor. We further show that the altered metabolism of IDH-mutant gliomas maintains this axis in bystander cells and that pharmacological inhibition of tryptophan metabolism can reverse immunosuppression. In conclusion, we provide evidence of a glioma genotype-dependent intratumoral network of resident and recruited myeloid cells and identify tryptophan metabolism as a target for immunotherapy of IDH-mutant tumors.