[Establishment of a mutation prediction model for evaluating the efficacy of immunotherapy in renal carcinoma].

OBJECTIVE: To establish a mutation prediction model for efficacy assessment, the genomic sequencing data of renal cancer patients from the MSKCC (Memorial Sloan Kettering Cancer Center) pan-cancer immunotherapy cohort was used. METHODS: The genomic sequencing data of 121 clear cell renal cell carcinoma patients treated with immune checkpoint inhibitors (ICI) in the MSKCC pan-cancer immunotherapy cohort were obtained from cBioPortal database (http://www.cbioportal.org/) and they were analyzed by univariate and multivariate Cox regression analysis to identify mutated genes associated with ICI treatment efficacy, and we constructed a comprehensive prediction model for drug efficacy of ICI based on mutated genes using nomogram. Survival analysis and time-dependent receiver operator characteristic curves were performed to assess the prognostic value of the model. Transcriptome and genomic sequencing data of 538 renal cell carcinoma patients were obtained from the TCGA database (https://portal.gdc.cancer.gov/). Gene set enrichment analysis was used to identify the potential functions of the mutated genes enrolled in the nomogram. RESULTS: We used multivariate Cox regression analysis and identified mutations in PBRM1 and ARID1A were associated with treatment outcomes in the patients with renal cancer in the MSKCC pan-cancer immunotherapy cohort. Based on this, we established an efficacy prediction model including age, gender, treatment type, tumor mutational burden (TMB), PBRM1 and ARID1A mutation status (HR=4.33, 95%CI: 1.42-13.23, P=0.01, 1-year survival AUC=0.700, 2-year survival AUC=0.825, 3-year survival AUC=0.776). The validation (HR=2.72, 95%CI: 1.12-6.64, P=0.027, 1-year survival AUC=0.694, 2-year survival AUC=0.709, 3-year survival AUC=0.609) and combination (HR=2.20, 95%CI: 1.14-4.26, P=0.019, 1-year survival AUC=0.613, 2-year survival AUC=0.687, 3-year survival AUC=0.526) sets confirmed these results. Gene set enrichment analysis indicated that PBRM1 was involved in positive regulation of epithelial cell differentiation, regulation of the T cell differentiation and regulation of humoral immune response. In addition, ARID1A was involved in regulation of the T cell activation, positive regulation of T cell mediated cyto-toxicity and positive regulation of immune effector process. CONCLUSION: PBRM1 and ARID1A mutations can be used as potential biomarkers for the evaluation of renal cancer immunotherapy efficacy. The efficacy prediction model established based on the mutation status of the above two genes can be used to screen renal cancer patients who are more suitable for ICI immunotherapy.

Fluorescence immunoassay of alpha-fetoprotein with iron(III) tetrasulfonatophthalocyanine as a mimetic enzyme labeling reagent.

A new fluorimetric immunoassay for alpha-fetoprotein (AFP) has been developed using a novel promising mimetic peroxidase, iron(III) tetrasulfonatophthalocyanine (FeTSPc), as a labeling reagent to catalyze the fluorescence reaction of P- hydroxyphenylacetic acid (P-HPA) and hydrogen peroxide (H2O2). In the competitive immunoassay, anti-AFP antibody was coated on a 96-well plate (polystyrene) and a constant amount of FeTSPc-labeled AFP and a known amount of test solution were added. Non-labeled and FeTSPc-labeled AFP compete for binding to the plate-bound antibody. After the immunoreaction, the immunochemically adsorbed FeTSPc-AFP conjugate moiety was determined by measuring the fluorescence produced in a solution containing P-HPA and H2O2. AFP can be determined in the concentration range of 1-300 ng mL(-1) with a detection limit of 0.5 ng mL(-1).