AUTHOR=Zeng Jie , Yi Jianing , Tan Siyi , Zeng Yuanjun , Zou Lianhong , Zhang Chaojie , Liu Luyao , Yi Pingyong , Fan Peizhi , Yu Jie 

TITLE=GPI: An indicator for immune infiltrates and prognosis of human breast cancer from a comprehensive analysis

JOURNAL=Frontiers in Endocrinology

VOLUME=13

YEAR=2022

URL=https://www.frontiersin.org/journals/endocrinology/articles/10.3389/fendo.2022.995972

DOI=10.3389/fendo.2022.995972

ISSN=1664-2392

ABSTRACT=<p>Glucose-6-phosphate isomerase (<italic>GPI</italic>) plays an important part in gluconeogenesis and glycolysis through the interconversion of <sc>d</sc>-glucose-6-phosphate and <sc>d</sc>-fructose-6-phosphate, and its clinical significance still remains unclear in breast cancer (BRCA). We analyzed the expressions of <italic>GPI</italic> in BRCA patients to determine prognostic values. Our results showed that the expression levels of <italic>GPI</italic> were upregulated in BRCA patients, and a high <italic>GPI</italic> expression is correlated with poor overall survival (OS) in BRCA. At the same time, a high <italic>GPI</italic> expression is correlated with poor clinicopathological characteristics, such as stage III, over 60 years old, N3, HER2 negative, and estrogen receptor (ER) positive. Further analysis of the influence of <italic>GPI</italic> on the prognosis of BRCA suggested that 50 genes and 10 proteins were positively correlated with <italic>GPI</italic>, and these genes and proteins were mainly involved in cell cycle signaling pathways. In addition, in this study, we observed that <italic>GPI</italic> was closely related to <italic>N</italic><sup>6</sup>-methyladenosine (m6A) RNA methylation modification and immune cell infiltration and ferroptosis-related gene expression in BRCA, and there was a difference in m6A RNA methylation alterations, immune cell infiltration, and ferroptosis-related gene expression between the high <italic>GPI</italic> expression group and the low <italic>GPI</italic> expression group. Finally, we found that <italic>GPI</italic> in BRCA had 2.6% gene alterations, and BRCA patients with gene alteration of <italic>GPI</italic> had a poor prognosis in disease-free survival (DFS). Altogether, our work strongly suggested that <italic>GPI</italic> may serve as a new prognostic biomarker for BRCA patients.</p>