Title | Phenformin Enhances the Efficacy of ERK Inhibition in NF1-Mutant Melanoma. |
Publication Type | Journal Article |
Year of Publication | 2017 |
Authors | Trousil S, Chen S, Mu C, Shaw FM, Yao Z, Ran Y, Shakuntala T, Merghoub T, Manstein D, Rosen N, Cantley LC, Zippin JH, Zheng B |
Journal | J Invest Dermatol |
Volume | 137 |
Issue | 5 |
Pagination | 1135-1143 |
Date Published | 2017 May |
ISSN | 1523-1747 |
Keywords | Apoptosis, Cell Line, Tumor, Cell Survival, Drug Synergism, Extracellular Signal-Regulated MAP Kinases, Humans, Indazoles, Melanoma, Mutation, Neurofibromin 1, Oxygen Consumption, Phenformin, Piperazines |
Abstract | Inactivation of the tumor suppressor neurofibromin 1 (NF1) presents a newly characterized melanoma subtype, for which currently no targeted therapies are clinically available. Preclinical studies suggest that extracellular signal-regulated kinase (ERK) inhibitors are likely to provide benefit, albeit with limited efficacy as a single agent; therefore, there is a need for rationally designed combination therapies. Here, we evaluate the combination of the ERK inhibitor SCH772984 and the biguanide phenformin. A combination of both compounds showed potent synergy in cell viability assays and cooperatively induced apoptosis. Treatment with both drugs was required to fully suppress mechanistic target of rapamycin signaling, a known effector of NF1 loss. Mechanistically, SCH772984 increased the oxygen consumption rate, indicating that these cells relied more on oxidative phosphorylation upon treatment. Consistently, SCH772984 increased expression of the mitochondrial transcriptional coactivator peroxisome proliferator-activated receptor gamma, coactivator 1-α. In contrast, cotreatment with phenformin, an inhibitor of complex I of the respiratory chain, decreased the oxygen consumption rate. SCH772984 also promoted the expansion of the H3K4 demethylase KDM5B (also known as JARID1B)-positive subpopulation of melanoma cells, which are slow-cycling and treatment-resistant. Importantly, phenformin suppressed this KDM5B-positive population, which reduced the emergence of SCH772984-resistant clones in long-term cultures. Our results warrant the clinical investigation of this combination therapy in patients with NF1 mutant melanoma. |
DOI | 10.1016/j.jid.2017.01.013 |
Alternate Journal | J. Invest. Dermatol. |
PubMed ID | 28143781 |
PubMed Central ID | PMC5392423 |
Grant List | K08 CA160657 / CA / NCI NIH HHS / United States P01 CA120964 / CA / NCI NIH HHS / United States P30 CA008748 / CA / NCI NIH HHS / United States R01 CA166717 / CA / NCI NIH HHS / United States |