USP18 enhances the resistance of BRAF-mutated melanoma cells to vemurafenib by stabilizing cGAS expression to induce cell autophagy

•cGAS was increased in vemurafenib-resistant patients with BRAF V600E mutant melanoma.•Knockdown of cGAS inhibited the resistance to vemurafenib in A2058R cells.•USP18 could deubiquitinate cGAS to promote its protein stability.•USP18 promoted vemurafenib-induced protective autophagy by stabilizing cGAS protein.•Our study highlighted the significance of USP18 in BRAF V600E mutant melanoma.