Numerous genetic and biological processes have been linked to the func-tion of microRNAs (miRNAs), which regulate gene expression by targeting messenger RNA (mRNA). It is commonly acknowledged that miRNAs play a role in the development of disease and the embryology of mammals. To further understand its function in the oncogenic process, the expression of the miRNA profile in cancer has been investigated. Despite being referred to as a noteworthy miRNA in cancer, it is unknown whether hsa-miR-1225-5p plays a part in the in vitro progression of the luminal A and luminal B subtypes of breast cancer. We proposed that a synthetic hsa-miR-1225-5p molecule be expressed in breast cancer cell lines and its activity be evaluated with the aim of studying its function in the development of luminal breast cancer. In terms of the typical cancer progression stages, such as proliferation, survival, migration, and invasion, we investigated the role of hsa-miR-1225-5p in luminal A and B breast cancer cell lines. Additionally, using bioinformatics databases, we thoroughly explored the target score-based prediction of miRNA-mRNA interaction. Our study showed that the expression of miR-1225-5p significantly inhibited the in vitro growth of luminal A and B breast cancer cell lines. The results were supported by a bioinformatic analysis and a detailed gene network that boosts the activation of signaling pathways required for cancer progression.