Level of cytoplasmic thioredoxin reductase 1 in prostate tissue is associated with prostate cancer Gleason score, total antioxidant capacity and erythrocyte glutathione peroxidase activity (136.2)

Abstract

Thioredoxin reductase 1 (TrxR1) is a member of the thioredoxin system, and a ubiquitous protein disulfide reductase involved in various intracellular inflammatory and oxidative processes. This study was conducted to determine the association between prostate tissue expression of TrxR1 levels and prostate cancer (PCa) Gleason score, dietary total antioxidant capacity (TAC), and erythrocyte glutathione peroxidase (GPx) activity using data from PCaP, a study of incident PCa among African and Caucasian Americans. Cytoplasmic and nuclear TrxR1 levels were measured using immunohistochemical staining of PCa on diagnostic biopsy sections from 55 men and visually scored in a blinded fashion by a pathologist (slides scored 0 to 3, with larger numbers indicating greater intensity of staining). Associations between PCa Gleason score and cytoplasmic TrxR1 levels of benign and malignant cells, and the difference in TrxR1 level between benign and malignant cells (ΔTrxR1), were determined using Fisher’s Exact test, α=0.05. TrxR1 was associated with dietary TAC (p<0.05) in benign cells and GPx (p<0.05) in malignant cells; ΔTrxR1 was found positively associated with Gleason score (p<0.05). These results warrant additional research on oxidative stress and prostate carcinogenesis.Acknowledgement: The authors thank the staff, advisory committees and research subjects participating in the North Carolina‐Louisiana Prostate Cancer Project (PCaP) study for their important contributions.Grant Funding Source: Support by NIH Cancer Epidemiology Small Grant #1R03CA159421‐01A1 and DOD DAMD 17‐03‐2‐0052