Radiation prevents tumor progression by inhibiting the miR‑93‑5p/EphA4/NF‑κB pathway in triple‑negative breast cancer

Breast cancer (BC) is the most common type of cancer in women. Triple-negative BC (TNBC) constitutes 10–15% of all BC cases and is associated with a poor prognosis. It has previously been reported that microRNA (miR)-93-5p is dysregulated in plasma exosomes from patients with BC and that miR-93-5p improves radiosensitivity in BC cells. The present study identified EphA4 as a potential target gene of miR-93-5p and investigated the pathway related to miR-93-5p in TNBC. Cell transfection and nude mouse experiments were performed to verify the role of the miR-93-5p/EphA4/NF-κB pathway. Moreover, miR-93-5p, EphA4 and NF-κB were detected in clinical patients. The results revealed that EphA4 and NF-κB were downregulated in the miR-93-5p overexpression group. By contrast, EphA4 and NF-κB expression levels were not significantly altered in the miR-93-5p overexpression + radiation group compared with those in the radiation group. Furthermore, overexpression of miR-93-5p with concomitant radiation therapy significantly decreased the growth of TNBC tumors in vivo. In conclusion, the present study revealed that miR-93-5p targeted EphA4 in TNBC through the NF-κB pathway. However, radiation therapy prevented tumor progression by inhibiting the miR-93-5p/EphA4/NF-κB pathway. Therefore, it would be interesting to elucidate the role of miR-93-5p in clinical research.