Sundstroem 2019 Acta Neuropathol Commun

From Bioblast
Publications in the MiPMap
SundstrΓΈm T, Prestegarden L, Azuaje F, Aasen SN, RΓΈsland GV, Varughese JK, Bahador M, Bernatz S, Braun Y, Harter PN, Skaftnesmo KO, Ingham ES, Mahakian LM, Tam S, Tepper CG, Petersen K, Ferrara KW, Tronstad KJ, Lund-Johansen M, Beschorner R, Bjerkvig R, Thorsen F (2019) Inhibition of mitochondrial respiration prevents BRAF-mutant melanoma brain metastasis. Acta Neuropathol Commun 7:55.

Β» PMID: 30971321 Open Access Β»O2k-brief

Sundstroem T, Prestegarden L, Azuaje F, Aasen SN, Roesland GV, Varughese JK, Bahador M, Bernatz S, Braun Y, Harter PN, Skaftnesmo KO, Ingham ES, Mahakian LM, Tam S, Tepper CG, Petersen K, Ferrara KW, Tronstad KJ, Lund-Johansen M, Beschorner R, Bjerkvig R, Thorsen F (2019) Acta Neuropathol Commun

Abstract: Melanoma patients carry a high risk of developing brain metastases, and improvements in survival are still measured in weeks or months. Durable disease control within the brain is impeded by poor drug penetration across the blood-brain barrier, as well as intrinsic and acquired drug resistance. Augmented mitochondrial respiration is a key resistance mechanism in BRAF-mutant melanomas but, as we show in this study, this dependence on mitochondrial respiration may also be exploited therapeutically. We first used high-throughput pharmacogenomic profiling to identify potentially repurposable compounds against BRAF-mutant melanoma brain metastases. One of the compounds identified was Ξ²-sitosterol, a well-tolerated and brain-penetrable phytosterol. Here we show that Ξ²-sitosterol attenuates melanoma cell growth in vitro and also inhibits brain metastasis formation in vivo. Functional analyses indicated that the therapeutic potential of Ξ²-sitosterol was linked to mitochondrial interference. Mechanistically, Ξ²-sitosterol effectively reduced mitochondrial respiratory capacity, mediated by an inhibition of mitochondrial complex I. The net result of this action was increased oxidative stress that led to apoptosis. This effect was only seen in tumor cells, and not in normal cells. Large-scale analyses of human melanoma brain metastases indicated a significant role of mitochondrial complex I compared to brain metastases from other cancers. Finally, we observed completely abrogated BRAF inhibitor resistance when vemurafenib was combined with either Ξ²-sitosterol or a functional knockdown of mitochondrial complex I. In conclusion, based on its favorable tolerability, excellent brain bioavailability, and capacity to inhibit mitochondrial respiration, Ξ²-sitosterol represents a promising adjuvant to BRAF inhibitor therapy in patients with, or at risk for, melanoma brain metastases. β€’ Keywords: BRAF V600E, Brain metastasis, Cancer, Melanoma, Treatment, Ξ²-Sitosterol β€’ Bioblast editor: Plangger M β€’ O2k-Network Lab: NO Bergen Tronstad KJ


Labels: MiParea: Respiration, nDNA;cell genetics, Pharmacology;toxicology  Pathology: Cancer 

Organism: Human  Tissue;cell: Endothelial;epithelial;mesothelial cell  Preparation: Permeabilized cells 


Coupling state: LEAK, ET  Pathway: N, S, NS, ROX  HRR: Oxygraph-2k 

Labels, 2019-04, O2k-brief 

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