Elevated Expression of LINC02257 and LINC00659 in Breast Cancer is Associated with Poor Survival and Immune Cell Infiltration

Abstract

Background Long non-coding RNAs (lncRNAs) regulate intracellular pathways and play a pivotal role in cancer development. Although some studies have shown that the expression levels of LINC02257 and LINC00659 may be associated with the development and malignancy of some cancers, their specific roles in breast cancer (BC) are still unclear. This study aimed to investigate changes in the expression of these two lncRNAs in BC and to examine the relationships between their expression and patient prognosis, immune cell infiltration, and malignancy-related genes.Methods BC data from The Cancer Genome Atlas (TCGA) and GSE103001 were preprocessed. Univariate and multivariate Cox regression analyses were employed to investigate the relationship between candidate lncRNA expression and patient survival. Co-expression networks identified potential pathways associated with lncRNAs. The rate of immune cell infiltration in samples exhibiting high expression levels of LINC02257 and LINC00659 was evaluated utilizing the EPIC algorithm and subsequently examined with the CIBERSORT algorithm. Using RT-qPCR, the expression levels of candidate genes were examined in 50 BC samples and their adjacent normal samples.Results The expression levels of LINC02257 and LINC00659 were elevated in BC samples according to TCGA data and GSE103001. The results of the survival analysis showed that their increased expression was associated with a poor prognosis in patients, independent of clinical characteristics. Co-expression network findings showed a correlation between the expression of these two lncRNAs and genes related to metastasis and cell proliferation. Samples exhibiting elevated expression levels of LINC00659 and LINC02257 were correlated with decreased infiltration of B cells and CD8 + T cells. Conversely, heightened expression was associated with increased infiltration of cancer-associated fibroblasts. RT-qPCR showed increased expression levels of LINC00659 and LINC02257 in cancer samples compared to adjacent normal tissue.Conclusion This study found that LINC02257 and LINC00659 are upregulated in BC and are associated with malignancy-related genes and patient survival, suggesting their potential as therapeutic targets and prognostic biomarkers.