Comparative transcriptome revealed potential genes related with drug resistance in Melanoma

Chemotherapy remains a relatively ineffective and unsatisfactory treatment because of drug resistance in melanoma (whether due to intrinsic resistance or the use of cytostatic drugs). In order to explore the genes and signaling pathways related to melanoma drug resistance, the study presented here obtained drug-resistant melanoma cell lines of A375 and M14 by gradually increasing the concentration of dacarbazine (DTIC), followed by comparative transcriptomics studies (RNA-seq) and real-time quantitative PCR (RT-qPCR) and Western Blotting validation. The results showed that after 8 months of continuous treatment, the IC50 values of A375 and M14 to DTIC were increased by more than 5 folds. Meanwhile, flow cytometry analysis found that drug-resistant melanoma cells have a significant ability to resist apoptosis induced by DTIC. Subsequently, RNA-seq revealed high expression of SENP1 and abnormal activation of the Hippo signaling pathway in drug-resistant cells. Finally, we found that compared with wild-type cells, the expressions of SENP1 and YAP were both up-regulated in drug-resistant cells via RT-qPCR and Western Blotting. Roles of SENP1 in drug resistance was finally verified via its overexpression in normal A375 cell lines. Therefore, this paper infers that there is a positive correlation between the ubiquitin-specific protease SENP1 and the drug resistance of melanoma. Meanwhile, the up-regulation of its expression may lead to changes in the Hippo signaling pathway and increase the resistance of melanoma to DTIC.