Abstract
Chemotherapy resistance poses an obstacle for effective treatment of uveal melanoma. In this study, we aim to investigate the effects of jumonji domain containing 2C (JMJD2C)-mediated mouse double minute-2 homolog (MDM2)/p53/interleukin 5 receptor subunit alpha (IL5RA) axis on cisplatin (CDDP) resistance in uveal melanoma. RT-qPCR and Western blot assay were performed to determine their expression patterns in uveal melanoma cell line (MUM-2B) and CDDP-resistant cell line (MUM-2B/CDDP). The enrichment of H3K9me3 in MDM2 promoter region was examined by ChIP, and the binding between p53 and ubiquitin in MUM-2B cells testified by co-IP assay. Following overexpression or silencing of JMJD2C/MDM2/p53/IL5RA, the 50% concentration of inhibition (IC50) and the biological characteristics of MUM-2B and MUM-2B/CDDP cells were examined using CCK-8 assay, SA-β-gal staining, fluorescence-activated cell sorting analysis, and Transwell assay. Finally, the tumorigenicity of transplanted MUM-2B and MUM-2B/CDDP cells in nude mice was assessed. JMJD2C was documented to be highly expressed in uveal melanoma cells, promoting the CDDP resistance. Histone demethylase JMJD2C removed the H3K9me3 modification of MDM2 promoter, which promoted the expression of MDM2. MDM2 enhanced the IL5RA expression through stimulating the ubiquitination and degradation of p53, thus inducing CDDP resistance of uveal melanoma cells. Furthermore, the results of in vivo experiments revealed that JMJD2C mediated the MDM2/p53/IL5RA axis to expedite the growth of uveal melanoma and augment the CDDP resistance. Taken together, JMJD2C can induce histone demethylation to upregulate MDM2, thereby ubiquitinating p53 and upregulating IL5RA. As a consequence, CDDP resistance in uveal melanoma is ultimately accelerated.