Icariside II sensitizes osteosarcoma to doxorubicin through the lincROR/Wnt/β-catenin signaling regulatory axis.

Doxorubicin (DOX) is a widely used chemotherapeutic drug for human osteosarcoma (OS). However, the acquired resistance of OS to DOX is a common phenomenon among OS patients, which seriously constrains its therapeutic efficacy in clinical practice. Improving the sensitivity of OS cells to DOX is therefore clinically significant for OS patients. Traditional Chinese medicine provides a potential strategy for reversing DOX resistance, among which Icariside II (ICS II), the flavonol glycoside derived from epimedium herb, has been reported to alleviate drug resistance in a variety of cancers, but the specific mechanism is still unclear. The emergence of long non-coding RNAs (lincRNAs) opens a new door for the mechanism underlying drug resistance. As an important carcinogenic lincRNA, lincROR was frequently dysregulated in various cancers and closely linked with multiple biological activities including proliferation, migration, invasion, and drug resistance. In the present study, a positive correlation between lincROR and DOX resistance was identified in OS cells. It was also found that lincROR overexpression promoted while its knockdown suppressed the DOX resistance in vitro and in vivo. The further investigation showed that the inactivation of Wnt/β-catenin induced by lincROR actively participated in this Icariside II-mediated DOX resistance. In summary, Icariside II sensitized the OS cells to DOX treatment and promoted the therapeutic effects mainly through the lincROR/Wnt/β-catenin regulatory axis.