PMID- 36765792 OWN - NLM STAT- PubMed-not-MEDLINE LR - 20230213 IS - 2072-6694 (Print) IS - 2072-6694 (Electronic) IS - 2072-6694 (Linking) VI - 15 IP - 3 DP - 2023 Jan 29 TI - Kynureninase Upregulation Is a Prominent Feature of NFR2-Activated Cancers and Is Associated with Tumor Immunosuppression and Poor Prognosis. LID - 10.3390/cancers15030834 [doi] LID - 834 AB - The nuclear factor erythroid 2-related factor 2 (NRF2) pathway is frequently activated in various cancer types. Aberrant activation of NRF2 in cancer is attributed to gain-of-function mutations in the NRF2-encoding gene NFE2L2 or a loss of function of its suppressor, Kelch-like ECH-associated protein 1 (KEAP1). NRF2 activation exerts pro-tumoral effects in part by altering cancer cell metabolism. Previously, we reported a novel mechanism of NRF2 tumoral immune suppression through the selective upregulation of the tryptophan-metabolizing enzyme kynureninase (KYNU) in lung adenocarcinoma. In the current study, we explored the relevance of NRF2-mediated KYNU upregulation across multiple cancer types. Specifically, using a gene expression dataset for 9801 tumors representing 32 cancer types from The Cancer Genome Atlas (TCGA), we demonstrated that elevated KYNU parallels increased gene-based signatures of NRF2-activation and that elevated tumoral KYNU mRNA expression is strongly associated with an immunosuppressive tumor microenvironment, marked by high expression of gene-based signatures of Tregs as well as the immune checkpoint blockade-related genes CD274 (PDL-1), PDCD1 (PD-1), and CTLA4, regardless of the cancer type. Cox proportional hazard models further revealed that increased tumoral KYNU gene expression was prognostic for poor overall survival in several cancer types, including thymoma, acute myeloid leukemia, low-grade glioma, kidney renal papillary cell carcinoma, stomach adenocarcinoma, and pancreatic ductal adenocarcinoma (PDAC). Using PDAC as a model system, we confirmed that siRNA-mediated knockdown of NRF2 reduced KYNU mRNA expression, whereas activation of NFE2L2 (the coding gene for NRF2) through either small-molecule agonists or siRNA-mediated knockdown of KEAP1 upregulated KYNU in PDAC cells. Metabolomic analyses of the conditioned medium from PDAC cell lines revealed elevated levels of KYNU-derived anthranilate, confirming that KYNU was enzymatically functional. Collectively, our study highlights the activation of the NRF2-KYNU axis as a multi-cancer phenomenon and supports the relevance of tumoral KYNU as a marker of tumor immunosuppression and as a prognostic marker for poor overall survival. FAU - Leon-Letelier, Ricardo A AU - Leon-Letelier RA AUID- ORCID: 0000-0001-7575-0453 AD - Department of Clinical Cancer Prevention, The University of Texas MD Anderson Cancer Center, Houston, TX 77030, USA. FAU - Abdel Sater, Ali H AU - Abdel Sater AH AUID- ORCID: 0000-0002-8494-8514 AD - Department of Clinical Cancer Prevention, The University of Texas MD Anderson Cancer Center, Houston, TX 77030, USA. FAU - Chen, Yihui AU - Chen Y AUID- ORCID: 0000-0002-3528-6104 AD - Department of Clinical Cancer Prevention, The University of Texas MD Anderson Cancer Center, Houston, TX 77030, USA. FAU - Park, Soyoung AU - Park S AD - Department of Clinical Cancer Prevention, The University of Texas MD Anderson Cancer Center, Houston, TX 77030, USA. FAU - Wu, Ranran AU - Wu R AUID- ORCID: 0000-0002-6276-1425 AD - Department of Clinical Cancer Prevention, The University of Texas MD Anderson Cancer Center, Houston, TX 77030, USA. FAU - Irajizad, Ehsan AU - Irajizad E AD - Department of Biostatistics, The University of Texas MD Anderson Cancer Center, Houston, TX 77030, USA. FAU - Dennison, Jennifer B AU - Dennison JB AD - Department of Clinical Cancer Prevention, The University of Texas MD Anderson Cancer Center, Houston, TX 77030, USA. FAU - Katayama, Hiroyuki AU - Katayama H AUID- ORCID: 0000-0003-3117-1390 AD - Department of Clinical Cancer Prevention, The University of Texas MD Anderson Cancer Center, Houston, TX 77030, USA. FAU - Vykoukal, Jody V AU - Vykoukal JV AD - Department of Clinical Cancer Prevention, The University of Texas MD Anderson Cancer Center, Houston, TX 77030, USA. FAU - Hanash, Samir AU - Hanash S AD - Department of Clinical Cancer Prevention, The University of Texas MD Anderson Cancer Center, Houston, TX 77030, USA. FAU - Ostrin, Edwin J AU - Ostrin EJ AUID- ORCID: 0000-0002-4538-6539 AD - Department of General Internal Medicine, The University of Texas MD Anderson Cancer Center, Houston, TX 77030, USA. FAU - Fahrmann, Johannes F AU - Fahrmann JF AD - Department of Clinical Cancer Prevention, The University of Texas MD Anderson Cancer Center, Houston, TX 77030, USA. LA - eng GR - 2P30CA016672-38/GF/NIH HHS/United States GR - 619882/American Lung Association Lung Cancer Discovery Award/ PT - Journal Article DEP - 20230129 PL - Switzerland TA - Cancers (Basel) JT - Cancers JID - 101526829 PMC - PMC9913753 OTO - NOTNLM OT - KYNU OT - NRF2 OT - immunosuppression OT - multi-cancer OT - prognosis COIS- The authors declare no conflict of interest. EDAT- 2023/02/12 06:00 MHDA- 2023/02/12 06:01 PMCR- 2023/01/29 CRDT- 2023/02/11 01:03 PHST- 2023/01/05 00:00 [received] PHST- 2023/01/24 00:00 [revised] PHST- 2023/01/27 00:00 [accepted] PHST- 2023/02/11 01:03 [entrez] PHST- 2023/02/12 06:00 [pubmed] PHST- 2023/02/12 06:01 [medline] PHST- 2023/01/29 00:00 [pmc-release] AID - cancers15030834 [pii] AID - cancers-15-00834 [pii] AID - 10.3390/cancers15030834 [doi] PST - epublish SO - Cancers (Basel). 2023 Jan 29;15(3):834. doi: 10.3390/cancers15030834.