Complex-I alteration and enhanced mitochondrial fusion are associated with prostate cancer progression

Mitochondria (mt) encoded respiratory complex-I (RCI) mutations and their pathogenicity remain largely unknown in prostate cancer (PCa). Little is known about the role of mtDNA loss on mt integrity in PCa.

We determined mtDNA mutation in human and mice PCa and assessed the impact of mtDNA depletion on mt integrity. We also examined whether the circulating exosomes from PCa patients are transported to mt and carry mtDNA or mt proteins. We have employed next generation sequencing of the whole mt genome in human and Hi-myc PCa. The impact of mtDNA depletion on mt integrity, presence of mtDNA and protein in sera exosomes was determined. A co-culture of human PCa cells and the circulating exosomes followed by confocal imaging determined co-localization of exosomes and mt. We observed frequent RCI mutations in human and Hi-myc PCa which disrupted corresponding complex protein expression. Depletion of mtDNA in PCa cells influenced mt integrity, increased expression of MFN1, MFN2, PINK1 and decreased expression of MT-TFA. Increased mt fusion and expression of PINK1 and DNM1L were also evident in the Hi-myc tumors. RCI-mtDNA, MFN2 and IMMT proteins were detected in the circulating exosomes of men with benign prostate hyperplasia (BPH) and progressive PCa. Circulating exosomes and mt co-localized in PCa cells. Our study identified new pathogenic RCI mutations in PCa and defined the impact of mtDNA loss on mt integrity. Presence of mtDNA and mt proteins in the circulating exosomes implicated their usefulness for biomarker development. This article is protected by copyright. All rights reserved.

Journal of cellular physiology. 2015 Nov 04 [Epub ahead of print]

Julie V Philley, Anbarasu Kannan, Wenyi Qin, Edward R Sauter, Mitsuo Ikebe, Kate L Hertweck, Dean A Troyer, Oliver J Semmes, Santanu Dasgupta

Department of Medicine, The University of Texas Health Science Center at Tyler, Tyler, Texas. , Department of Cellular and Molecular Biology, The University of Texas Health Science Center at Tyler, Tyler, Texas. , Department of Surgery, The University of Texas Health Science Center at Tyler, Tyler, Texas. , Department of Surgery, The University of Texas Health Science Center at Tyler, Tyler, Texas. , Department of Cellular and Molecular Biology, The University of Texas Health Science Center at Tyler, Tyler, Texas. , Department of Biology, The University of Texas at Tyler, Tyler, Texas. , Department of Microbiology and Molecular Cell Biology, Eastern Virginia Medical School, Norfolk, Virginia. , Department of Microbiology and Molecular Cell Biology, Eastern Virginia Medical School, Norfolk, Virginia. , Department of Cellular and Molecular Biology, The University of Texas Health Science Center at Tyler, Tyler, Texas.

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