P106 ENZYMES INVOLVED IN THE CATABOLISM OF TRYPTOPHAN IN THE PROGNOSIS OF BLADDER CANCER

Bladder cancer (BC) ranks third among the most common carcinomas in Brazil. Tumor immunology opens up perspectives for treatment, where the enzyme indoleamine 2,3-dioxygenase-1 (IDO1) stands out for degrading the amino acid tryptophan, initiating a cascade that culminates in the generation of catabolites (derived from kynurenine). These catabolites, in different associations, determine degrees of local immunosuppression. These catabolites are generated by other enzymes that have not yet been studied in BC. We analyzed the expression of enzymes involved in tryptophan catabolism in order to correlate them with the stage, recurrence, and progression of BC. Analysis of published microarray databases was performed using the NCBI (National Center of Biotechnology Information) and accessed through GEO Datasets (Gene Expression Omnibus). The descriptor “Bladder cancer” was used. Series that provided analysis of normal bladder tissue (Normal) versus BC, including cases of non-muscle invasive BC (CBNMI) and muscle invasive BC (CBMI), recurrence and progression. Statistical analysis was performed using the GEO2R and ROC curve was used. The transcripts were: Tryptophan 2,3-dioxygenase (TDO2), Indoleamine 2,3-dioxygenase (IDO1), Kynurenine Formamidase (AFMID), Kynureninase (KNYU), Kynurenine-oxoglutarate-transaminase 1 (KYAT1), and Kynurenine Monooxygenase (KMU). GSE13507 series was selected, with ten Normal samples and 165 BC samples, including 104 CBNMI and 61 CBMI cases. CBNMI was predicted by KYNU, AFMID, and KYAT1 (AUC of 0.625, 0.589, and 0.638, respectively; p<0.05), while for CBMI were, IDO1, TDO2, and KMO (AUC of 0.662, 0.633, and 0.601, respectively; p<0.05). No enzyme was found to be important in predicting progression; however, the IDO1 enzyme was predictive of recurrence (AUC of 0.366; p<0.05). A relationship between the two IDO1/KYNU was established, which improved the prediction of stage for CBNMI (AUC of 0.733, p<0.05), non-progression (AUC of 0.619, p<0.05), and non-recurrence (AUC of 0.626, p<0.05). The expression of enzymes involved in tryptophan catabolism may aid in the prognosis of BC. It is likely that these enzymes are involved in tumor immunomodulation, which will be explored in future studies.