Tumor-derived exosomal lncRNA-MIR193BHG promotes bone metastasis of breast cancer by targeting the miR-489-3p/DNMT3A signaling axis in osteoclasts.

BACKGROUND: Breast cancer exhibits high incidence and mortality among women, with distant metastasis, especially bone metastasis, being the leading cause of death. Despite advances in adjuvant therapies, bone metastasis remains a challenge for patient survival and quality of life. Exosomes, small vesicles capable of mediating intercellular communication, play a crucial role in tumor metastasis.

RESULTS: This study investigated the role of tumor-derived exosomal long noncoding RNA (lncRNA)-MIR193BHG in breast cancer bone metastasis. LncRNA-MIR193BHG was delivered to osteoclasts via exosomes and promoted osteoclast formation and activity by targeting the miR-489-3p/DNA methyltransferase 3A (DNMT3A) signaling axis, thereby accelerating breast cancer-induced osteolysis. Knockdown experiments demonstrated that reducing the levels of exosomal lncRNA-MIR193BHG significantly inhibited osteoclast differentiation and bone resorption, which was confirmed both in vitro and in vivo. Additionally, mechanistic studies revealed that lncRNA-MIR193BHG acted as a competitive endogenous RNA (ceRNA) interacting with miR-489-3p, regulating DNMT3A expression and subsequently affecting osteoclast differentiation.

CONCLUSIONS: These findings suggest that lncRNA-MIR193BHG plays a critical regulatory role in breast cancer bone metastasis, and the lncRNA-MIR193BHG/miR-489-3p/DNMT3A signaling axis could be a potential target for the treatment of breast cancer bone metastasis. Future studies should further explore the broader applicability of this mechanism and its clinical feasibility.