A ROSALIND® Case Study: Differentially expressed miRNAs in single hormone receptor-positive breast cancer

Estrogen (ER) and progesterone (PgR) receptors and HER2 are crucial in the assessment of breast cancer specimens due to their prognostic and predictive significance. Single hormone receptor-positive breast cancers are less common and their clinical course is less favorable than ER(+)/PgR(+) tumors. In this study, the main differences in miRNA expression amongst single hormone receptor-positive tumors were identified according to their HER2 status. miRNA expression profiling was done with the NanoString® nCounter® Human v3 miRNA Expression Assay and analyzed using ROSALIND powered by OnRamp Bio. miRNA expression in ER(−)/PgR(+) tumors resemble triple- and double-negative tumors, which may indicate that their biology is similar to basal-like carcinomas. ER(+)/PgR(−) tumors show higher expression of miRNAs typical for double-positive luminal carcinomas. The main differences in miRNA expression amongst single hormone receptor-positive tumors were found to be related to their HER2 status rather than to their hormonal receptor status. The effect on mRNA expression was estimated for four available miRNA-mRNA pairs (TGFB2–miR-141-3p, NEDD4L–miR-30a-5p, FGFR4–miR-424-5p, & SOCS2–miR-424-5p) was assessed, but no significant results were obtained.