Showing posts with label cisplatin and vemurafenib. Show all posts
Showing posts with label cisplatin and vemurafenib. Show all posts

Wednesday, June 19, 2013

Diabetes drug points the way to overcoming drug resistance in melanoma


Despite success with BRAFV600E inhibitors, therapeutic responses in patients with metastatic melanoma are short-lived because of the acquisition of drug resistance. Researchers  identified a mechanism of intrinsic multidrug resistance based on the survival of a tumor cell subpopulation. Treatment with various drugs, including cisplatin and vemurafenib, uniformly leads to enrichment of slow-cycling, long-term tumor-maintaining melanoma cells expressing the H3K4-demethylase JARID1B/KDM5B/PLU-1. Proteome-profiling revealed an upregulation in enzymes of mitochondrial oxidative-ATP-synthesis (oxidative phosphorylation) in this subpopulation. Inhibition of mitochondrial respiration blocked the emergence of the JARID1Bhigh subpopulation and sensitized melanoma cells to therapy, independent of their genotype. Our findings support a two-tiered approach combining anticancer agents that eliminate rapidly proliferating melanoma cells with inhibitors of the drug-resistant slow-cycling subpopulation.