EPHB6 mutation induces cell adhesion-mediated paclitaxel resistance via EPHA2 and CDH11 expression.

Mutations affect gene functions related to cancer behavior, including cell growth, metastasis, and drug responses. Genome-wide profiling of cancer mutations and drug responses has identified actionable targets that can be utilized for the management of cancer patients. Here, the recapitulation of pharmacogenomic data revealed that the mutation of EPHB6 is associated with paclitaxel resistance in cancer cells. Experimental data confirmed that the EPHB6 mutation induces paclitaxel resistance in various cancer types, including lung, skin, and liver cancers. EPHB6 mutation-induced paclitaxel resistance was mediated by an interaction with EPHA2, which promotes c-Jun N-terminal kinase (JNK)-mediated cadherin 11 (CDH11) expression. We demonstrated that EPHB6-mutated cells acquire cell adhesion-mediated drug resistance (CAM-DR) in association with CDH11 expression and RhoA/focal adhesion kinase (FAK) activation. Targeted inhibition of EPHA2 or CDH11 reversed the acquired paclitaxel resistance, suggesting its potential clinical utility. The present results suggest that the EPHB6 mutation and its downstream EPHA2/JNK/CDH11/RhoA/FAK signaling axis are novel diagnostic and therapeutic targets for overcoming paclitaxel resistance in cancer patients.