ArticleInternational journal of molecular sciences2021
Kynurenine/Tryptophan Ratio as a Potential Blood-Based Biomarker in Non-Small Cell Lung Cancer.
Article in International journal of molecular sciences, 2021. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Cited by 41 papers.
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Who cites it
41 citing papers in PubMed, 58 citations in OpenAlex.
- Smoking-Stratified Signal Decomposition and Feature Selection for Never-Smoker Cancer Classification in a Combined Lung-Breast Metabolomics Cohort.International journal of molecular sciences · 2026Article
- Rewiring tumor metabolism: heterogeneity, oncometabolites, and adaptive plasticity.Experimental hematology & oncology · 2026Review
- T-Cell Exhaustion in the Tumor Microenvironment: Subcellular Dysfunction, Pan-Cancer Characteristics, and Therapeutic Interventions.Advanced science (Weinheim, Baden-Wurttemberg, Germany) · 2026Review
- The Tryptophan Paradox: From Microbiome-Mediated Homeostasis to Tumor-Driven Immune Escape.International journal of molecular sciences · 2026Review
- Spatially resolved tryptophan-kynurenine niches in HNSCC: immunometabolic microdomains and therapeutic implications.Frontiers in immunology · 2026Review
- Tryptophan metabolism in tumor immune escape: mechanisms, cellular crosstalk, and therapeutic opportunities.Frontiers in immunology · 2026Review
- Role of Tryptophan Metabolism in Cancer.Cancer innovation · 2025Review
- Design, Synthesis, and Biological Evaluation of Dual Functional Inhibitors Targeting Indoleamine 2,3-dioxygenase 1 (IDO1) and Tryptophan 2,3-dioxygenase (TDO).ACS medicinal chemistry letters · 2025Article
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- The role of immune checkpoint molecules in PRRSV-2-induced immune modulation: insights from comparativeJournal of virology · 2025Article
- Tryptophan metabolism: From physiological functions to key roles and therapeutic targets in cancer (Review).Oncology reports · 2025Review
- Targeting the Kynurenine Pathway: A Novel Approach in Tumor Therapy.Expert reviews in molecular medicine · 2025Review
- CD103+ dendritic cell-fibroblast crosstalk via TLR9, TDO2, and AHR signaling drives lung fibrogenesis.JCI insight · 2025Article
- Circulating tryptophan-kynurenine pathway metabolites are associated with all-cause mortality among patients with stage I-III colorectal cancer.International journal of cancer · 2025Article
- Cellular Signaling of Amino Acid Metabolism in Prostate Cancer.International journal of molecular sciences · 2025Review
- Global research trends in tryptophan metabolism and cancer: a bibliometric and visualization analysis (2005-2024).Frontiers in oncology · 2025Article
- Article
- Tryptophan metabolism at the crossroads of the neuro-immuno-microbial axis: implications for precision medicine in chronic diseases.Frontiers in cellular and infection microbiology · 2025Review
- TDO2 inhibition counters Benzo[a]pyrene-induced immune evasion and suppresses tumorigenesis in lung adenocarcinoma.Cancer & metabolism · 2024Article
- Cervical mucus can be used for metabolite screening in cervical cancer.Cancer science · 2024Article
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Authors and funding
12 authors at 3 institutions in 1 country.
Funding
Abstract
The enzyme indoleamine 2,3-dioxygenase 1 (IDO1) degrade tryptophan (Trp) into kynurenine (Kyn) at the initial step of an enzymatic pathway affecting T cell proliferation. IDO1 is highly expressed in various cancer types and associated with poor prognosis. Nevertheless, the serum Kyn/Trp concentration ratio has been suggested as a marker of cancer-associated immune suppression. We measured Kyn and Trp in blood samples of a wide cohort of non-small-cell lung cancer (NSCLC) patients, before they underwent surgery, and analyzed possible correlations of the Kyn/Trp ratio with either IDO1 expression or clinical-pathological parameters. Low Kyn/Trp significantly correlated with low IDO1 expression and never-smoker patients; while high Kyn/Trp was significantly associated with older (≥68 years) patients, advanced tumor stage, and squamous cell carcinoma (Sqcc), rather than the adenocarcinoma (Adc) histotype. Moreover, high Kyn/Trp was associated, among the Adc group, with higher tumor stages (II and III), and, among the Sqcc group, with a high density of tumor-infiltrating lymphocytes. A trend correlating the high Kyn/Trp ratio with the probability of recurrences from NSCLC was also found. In conclusion, high serum Kyn/Trp ratio, associated with clinical and histopathological parameters, may serve as a serum biomarker to optimize risk stratification and therapy of NSCLC patients.
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