Expression of Four Long Non-coding RNAs in Breast Cancer and Their Relation with Patient's Prognosis

Objective To investigate the expression of EGOT, MEG3, KCNQ1OT1 and NEAT1 in breast cancer tissues and their correlation with clinicopathologic features and prognosis of breast cancer patients.

Methods Expression of four lncRNAs in 1097 breast cancer samples and 114 normal samples in the TCGA database were analyzed using UALCAN website. Survival curves were described by Kaplan-Meier Plotter website to analyze the relation between lncRNAs and the prognosis of breast cancer patients. The main functions of the proteins related to their expression were analyzed by LinkedOmics and ClueGO tools.

Results The expression of EGOT and MEG3 in breast cancer tissues were significantly lower than those in normal tissues (P < 0.05). Expression of KCNQ1OT1 was significantly lower in HER2-positive breast cancer (P < 0.05). The NEAT1 expression in stage Ⅳ breast cancer, HER2-positive and triple negative breast cancer tissues were significantly lower than that in normal tissues (P < 0.05). The expression levels of the four lncRNAs were significantly correlated with the relapse-free survival time (RFS) of breast cancer patients (P < 0.05), and the RFS and prognosis of breast cancer patients were relatively poor when lncRNA expression was low. The functional enrichment analysis results showed that all the proteins related to the expression of four lncRNAs were related to important biological processes or pathways.

Conclusion The four lncRNAs (EGOT, MEG3, KCNQ1OT1 and NEAT1) are down-regulated in breast cancer or some subtypes. They may be potential tumor suppressor factors in breast cancer and biological indicators for the prognosis of breast cancer patients.