Relative levels of let‑7a, miR‑17, miR‑27b, miR‑125a, miR‑125b and miR‑206 as potential molecular markers to evaluate grade, receptor status and molecular type in breast cancer

摘要: MicroRNAs (miRNAs/miRs) are a class of short, single‑stranded nucleic acids, which have been investigated as potential molecular markers for various types cancer. The gold‑standard and most sensitive method comparing miRNA levels in cancer tissues is reverse transcription‑quantitative polymerase chain reaction (RT‑qPCR). This technique uses stably expressed genes normalisation. aim the present study was to improve this model analysis context RT‑qPCR results. A total six known miRNAs (let‑7a, miR‑17, miR‑27b, miR‑125a, miR‑125b miR‑206), RNU6B RNA five mRNAs [erb‑b2 receptor tyrosine kinase 2 (ERBB2), hydroxymethylbilane synthase (RNA) II (DNA directed) polypeptide A] were analysed pair‑wise, order determine biomarker pairs best correlated with histological groups 27 breast samples. lowest P‑values highest area under curve values receiver operating characteristic used select optimum ratios discrimination among groups. Among 21 pairs, miR‑17/miR‑27b miR‑125a/RNU6B discriminated three samples different tumour grades (G classification). miR‑125b/miR‑206 two sizes (pT), let‑7a/RNU6B lymph node status (pN), let‑7a/miR‑125b negative positive oestrogen progesterone status. No pair found discriminate well between either or human epidermal growth factor (HER2) However, one miRNA/mRNA pair, miR‑125a/ERBB2, HER2‑negative from HER2‑positive grouped by immunohistological methods into classes: Luminal, HER2 basal (L, H B, respectively). In discern L selected: miR‑125a/miR‑125b miR‑125a/miR‑206. conclusion, pair‑wise data may be reasonable alternative standard using reference genes, such RNA, increase classification power biomarkers diagnostics.