Long Noncoding RNAs-LET Behave as a Noncoding Signature for Early-Onset Menarche and Late-Onset Menopause in Breast Cancer Patients

Breast cancer (BC) as a major cause of cancer-related death in women shows a very complex molecular and clinical phenotype, which has reduced the effectiveness of medical interventions. Evidence suggests that long noncoding RNAs (lncRNAs) are responsible for an important part of this complexity. This study aims to assess the expression and clinical implication of lncRNA LET in the pathobiology of BC.

Quantitative real-time polymerase chain reaction was used to measure the expression of lncRNA-LET in breast tumors and adjacent normal-appearing tissues from 4 BC patients, as well as normal mammary tissues. Moreover, a bioinformatics approach was applied to uncover the potential lncRNA-LET-mediated sponge regulatory network as LET/miRNA/mRNA crosstalk.

Our study revealed that lncRNA-LET was significantly down-expressed not only in breast tumors but also in normal appearing breast tissues samples from BC subjects compared with true normal breast tissues obtained from healthy women. The low level of lncRNA-LET was meaningfully associated with early-onset menarche (≤13 years) and late-onset menopause (≥50) in patients. Moreover, the bioinformatics analyses support that lncRNA-LET could function as a tumor suppressor miRNA sponge.

The results indicate that normal appearing breast tissues can undergo tumor-related molecular changes. Furthermore, they reveal the potential role of the dysregulation in LET-mediated ceRNA network in the pathophysiology of BC.