miR-455-5p promotes cell invasion and migration in breast cancer

MicroRNA (miR)-455-5p has been identified as a biomarker for various types of cancer and may therefore be involved in the regulation of cancer development and progression. However, the specific role and function of miR-455-5p in breast cancer remains unclear. The present study explored the expression levels and function of miR-455-5p in breast cancer. The results from reverse transcription-quantitative polymerase chain reaction analysis revealed that miR-455-5p was significantly upregulated in breast cancer. Clinically, increased expression of miR-455-5p predicted a poor survival rate and miR-455-5p was identified as one of the independent prognostic factors for breast cancer patients. Furthermore, results from wound healing and Transwell assays revealed that miR-455-5p accelerated invasiveness and migration capabilities of breast cancer cells. In addition, programmed cell death 4 was identified as a downstream target of miR-455-5p and its expression was observed to be negatively regulated by miR-455-5p. Overall, miR-455-5p may function as an oncogene in breast cancer, and may therefore be used as a prognostic marker for breast cancer patients.