{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,9,29]],"date-time":"2026-09-29T10:38:54Z","timestamp":1790678334458,"version":"4.1.0"},"reference-count":40,"publisher":"MDPI AG","issue":"16","license":[{"start":{"date-parts":[[2022,8,15]],"date-time":"2022-08-15T00:00:00Z","timestamp":1660521600000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"name":"cultural and educational grant agency of the Ministry of Education, Science, Research and Sports of the Slovak Republic (KEGA)","award":["015UVLF-4\/2022"],"award-info":[{"award-number":["015UVLF-4\/2022"]}]},{"name":"cultural and educational grant agency of the Ministry of Education, Science, Research and Sports of the Slovak Republic (KEGA)","award":["1\/0372\/17"],"award-info":[{"award-number":["1\/0372\/17"]}]},{"name":"Scientific Grant Agency of the Ministry of Education, Science, Research and Sport of the Slovak Republic and the Slovak Academy of Sciences (VEGA)","award":["015UVLF-4\/2022"],"award-info":[{"award-number":["015UVLF-4\/2022"]}]},{"name":"Scientific Grant Agency of the Ministry of Education, Science, Research and Sport of the Slovak Republic and the Slovak Academy of Sciences (VEGA)","award":["1\/0372\/17"],"award-info":[{"award-number":["1\/0372\/17"]}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["IJMS"],"abstract":"<jats:p>(1) Background: Tryptophan metabolism is known to be one of the important mechanisms used by cancer to evade immune surveillance. Altered tryptophan metabolism was studied in patients with pigmented malignant melanoma confirmed histologically by the anatomic stage grouping for cutaneous melanoma using clinical staging on the basis of the Breslow thickness of the melanoma, the degree of spread to regional lymph nodes, and by the presence of distant metastasis. (2) Methods: Urinary tryptophan metabolites were detected by RP-HPLC method. (3) Results: In the present work, we provided evidence of altered metabolism of all tryptophan pathways in melanoma patients. (4) Conclusions: Knowledge of the shifted serotonin pathway toward DHICA formation and kynurenine pathway shifted toward NAD+ production could serve in the early detection of the disease and the initiation of early treatment of malignant melanoma.<\/jats:p>","DOI":"10.3390\/ijms23169160","type":"journal-article","created":{"date-parts":[[2022,8,15]],"date-time":"2022-08-15T20:58:08Z","timestamp":1660597088000},"page":"9160","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":31,"title":["Tryptophan: Its Metabolism along the Kynurenine, Serotonin, and Indole Pathway in Malignant Melanoma"],"prefix":"10.3390","volume":"23","author":[{"ORCID":"https:\/\/orcid.org\/0000-0002-6291-4014","authenticated-orcid":false,"given":"Be\u00e1ta","family":"Hubkov\u00e1","sequence":"first","affiliation":[{"name":"Department of Medical and Clinical Biochemistry, Faculty of Medicine, Pavol Jozef \u0160af\u00e1rik University in Ko\u0161ice, Tr. SNP 1, 040 11 Ko\u0161ice, Slovakia"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-1614-460X","authenticated-orcid":false,"given":"Marcela","family":"Valko-Rokytovsk\u00e1","sequence":"additional","affiliation":[{"name":"Department of Chemistry, Biochemistry and Biophysics, University of Veterinary Medicine and Pharmacy in Ko\u0161ice, Komensk\u00e9ho 73, 041 81 Ko\u0161ice, Slovakia"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Be\u00e1ta","family":"\u010ci\u017em\u00e1rov\u00e1","sequence":"additional","affiliation":[{"name":"Department of Medical and Clinical Biochemistry, Faculty of Medicine, Pavol Jozef \u0160af\u00e1rik University in Ko\u0161ice, Tr. SNP 1, 040 11 Ko\u0161ice, Slovakia"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Marianna","family":"Z\u00e1bavn\u00edkov\u00e1","sequence":"additional","affiliation":[{"name":"KOREKTCHIR s.r.o., Zborovsk\u00e1 7, 040 01 Ko\u0161ice, Slovakia"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"M\u00e1ria","family":"Marekov\u00e1","sequence":"additional","affiliation":[{"name":"Department of Medical and Clinical Biochemistry, Faculty of Medicine, Pavol Jozef \u0160af\u00e1rik University in Ko\u0161ice, Tr. SNP 1, 040 11 Ko\u0161ice, Slovakia"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-5074-0125","authenticated-orcid":false,"given":"Anna","family":"Birkov\u00e1","sequence":"additional","affiliation":[{"name":"Department of Medical and Clinical Biochemistry, Faculty of Medicine, Pavol Jozef \u0160af\u00e1rik University in Ko\u0161ice, Tr. SNP 1, 040 11 Ko\u0161ice, Slovakia"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"1968","published-online":{"date-parts":[[2022,8,15]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"333","DOI":"10.4149\/301_151015N533","article-title":"Current Trends in the Treatment of Malignant Melanoma","volume":"63","author":"Bruchata","year":"2016","journal-title":"Neoplasma"},{"key":"ref_2","unstructured":"(2022, July 20). Melanoma: Statistics. Available online: https:\/\/www.cancer.net\/cancer-types\/melanoma\/statistics."},{"key":"ref_3","doi-asserted-by":"crossref","first-page":"1344","DOI":"10.1111\/j.1365-2133.2011.10490.x","article-title":"Serotonin Induces Melanogenesis via Serotonin Receptor 2 A","volume":"165","author":"Lee","year":"2011","journal-title":"Br. J. 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