Objective measurement and clinical significance of IDO1 protein in hormone receptor-positive breast cancer.

ABSTRACT:

Background

Immunostimulatory therapies targeting immune-suppressive pathways produce durable responses in advanced solid tumors. Indoleamine 2,3-dioxygenase (IDO) is the rate-limiting oxidoreductase that catalyzes the degradation of tryptophan to kynurenine. IDO induces immune tolerance by downregulating CD8+ and effector CD4+ T cell responses. IDO1, the most active isoform, is expressed in diverse tumor types and can be targeted using small molecule inhibitors. We used an objective, in situ assay to measure IDO1 in a collection of hormone receptor-positive breast cancers (HR+ BC).

Methods

IDO1 protein was measured using quantitative immunofluorescence in 362 stage I-III HR+ BC represented in tissue microarrays. IDO1 levels were determined in the tumor and stroma, and strati

SUBMITTER: Carvajal-Hausdorf DE 

PROVIDER: S-EPMC5644103 | biostudies-literature | 2017 Oct

REPOSITORIES: biostudies-literature