Abstract

Indoleamine 2,3-dioxygenase 1 (IDO1) plays an important role in the initiation and progression of breast cancer. DNA promoter methylation status has the potential to be used as a biomarker for predicting the response to immunotherapy. This study aimed to investigate the biological and clinical significance of IDO1 promoter methylation in breast cancer. We analyzed IDO1 promoter methylation and its relationship with survival, patient prognosis, immune cell infiltration, immune-related pathways, and the expression of key immunomodulators via bioinformatics methods in The Cancer Genome Atlas (TCGA) breast cancer cohort (779 samples). Furthermore, the IDO1 promoter methylation status and expression of the IDO1 gene in the basal subtype of breast cancer were investigated in vitro via a methylation-specific PCR (MSP) assay and quantitative polymerase chain reaction (qPCR). The IDO1 promoter was significantly hypomethylated in the basal subtype of breast cancer tissues compared with normal adjacent tissues, and this effect was correlated with high expression of IDO1, resulting in abundant immune cell infiltration, activation of immune-related pathways, and upregulation of key immunomodulators. The influence of IDO1 promoter hypomethylation on the prognosis of patients with breast cancer was also investigated. The promoter hypomethylation of IDO1 in the basal subtype of breast cancer and its correlation with high expression of IDO1 were also investigated in vitro. Our results showed that IDO1 promoter methylation is vital for regulating its expression, which leads to the development of a tumor microenvironment in breast cancer. IDO1 promoter methylation and expression are associated with prognosis, immune cell infiltration, immune-related pathways, and immunomodulator expression in breast cancer. Our findings provide evidence for the validation of IDO1 promoter methylation as a promising biomarker to predict responses to immune checkpoint inhibitors in patients with breast cancer.

Details

Title
Prognostic and immune correlation of IDO1 promoter methylation in breast cancer
Author
Ding, Shirong 1 ; Yang, Ruozhu 2 ; Meng, Jiahao 2 ; Guan, Xinyu 2 ; Hong, Yue 2 ; Xu, Jiachi 2 ; Qu, Limeng 2 ; Ji, Jingfen 2 ; Yi, Wenjun 2 ; Zou, Qiongyan 2 ; Long, Qian 2 

 the Second Xiangya Hospital of Central South University, Department of Oncology, Changsha, China (GRID:grid.452708.c) (ISNI:0000 0004 1803 0208) 
 the Second Xiangya Hospital of Central South University, Department of General Surgery, Changsha, China (GRID:grid.452708.c) (ISNI:0000 0004 1803 0208); Clinical Research Center for Breast Disease in Hunan Province, Changsha, China (GRID:grid.452708.c) 
Pages
27836
Publication year
2024
Publication date
2024
Publisher
Nature Publishing Group
e-ISSN
20452322
Source type
Scholarly Journal
Language of publication
English
ProQuest document ID
3128041803
Copyright
© The Author(s) 2024. This work is published under http://creativecommons.org/licenses/by-nc-nd/4.0/ (the “License”). Notwithstanding the ProQuest Terms and Conditions, you may use this content in accordance with the terms of the License.