Hsa-miR-199a-5 p is functionally relevant in progression from ductal carcinoma in situ to invasive breast tumours

A fundamental and clinically important step during the breast tumourigenesis is the transition from ductal carcinoma in situ (DCIS) to invasive ductal carcinoma (IDC). We analyzed miRNA expression profiles in 15 matched DCIS and IDC areas isolated by laser capture microdissection from formalin fixed and paraffin embedded (FFPE) breast cancer tissues using Illumina miRNA BeadChip microarray platform. Differential expression of hsa-miR-199a-5 p was further investigated by quantitative RT-PCR in 25 independent breast cancer samples. Invasion assays were performed in combination with knock down of hsa-miR-199a-5 p.…