title: Transcutaneous application of carbon dioxide (CO2) induces mitochondrial apoptosis in human malignant fibrous histiocytoma in vivo.
abstract: Mitochondria play an essential role in cellular energy metabolism and apoptosis. Previous studies have demonstrated that decreased mitochondrial biogenesis is associated with cancer progression. In mitochondrial biogenesis, peroxisome proliferator-activated receptor gamma coactivator-1 alpha (PGC-1α) regulates the activities of multiple nuclear receptors and transcription factors involved in mitochondrial proliferation. Previously, we showed that overexpression of PGC-1α leads to mitochondrial proliferation and induces apoptosis in human malignant fibrous histiocytoma (MFH) cells in vitro. We also demonstrated that transcutaneous application of carbon dioxide (CO(2)) to rat skeletal muscle induces PGC-1α expression and causes an increase in mitochondrial proliferation. In this study, we utilized a murine model of human MFH to determine the effect of transcutaneous CO(2) exposure on PGC-1α expression, mitochondrial proliferation and cellular apoptosis. PGC-1α expression was evaluated by quantitative real-time PCR, while mitochondrial proliferation was assessed by immunofluorescence staining and the relative copy number of mitochondrial DNA (mtDNA) was assessed by real-time PCR. Immunofluorescence staining and DNA fragmentation assays were used to examine mitochondrial apoptosis. We also evaluated the expression of mitochondrial apoptosis related proteins, such as caspases, cytochorome c and Bax, by immunoblot analysis. We show that transcutaneous application of CO(2) induces PGC-1α expression, and increases mitochondrial proliferation and apoptosis of tumor cells, significantly reducing tumor volume. Proteins involved in the mitochondrial apoptotic cascade, including caspase 3 and caspase 9, were elevated in CO(2) treated tumors compared to control. We also observed an enrichment of cytochrome c in the cytoplasmic fraction and Bax protein in the mitochondrial fraction of CO(2) treated tumors, highlighting the involvement of mitochondria in apoptosis. These data indicate that transcutaneous application of CO(2) may represent a novel therapeutic tool in the treatment of human MFH.
authors.affiliation: Department of Orthopaedic Surgery, Kobe University Graduate School of Medicine, Kusunoki-cho, Kobe, Japan.
authors.forename: Yasuo
authors.initials: Y
authors.lastname: Onishi
authors.forename: Teruya
authors.initials: T
authors.lastname: Kawamoto
authors.forename: Takeshi
authors.initials: T
authors.lastname: Ueha
authors.forename: Kenta
authors.initials: K
authors.lastname: Kishimoto
authors.forename: Hitomi
authors.initials: H
authors.lastname: Hara
authors.forename: Naomasa
authors.initials: N
authors.lastname: Fukase
authors.forename: Mitsunori
authors.initials: M
authors.lastname: Toda
authors.forename: Risa
authors.initials: R
authors.lastname: Harada
authors.forename: Masaya
authors.initials: M
authors.lastname: Minoda
authors.forename: Yoshitada
authors.initials: Y
authors.lastname: Sakai
authors.forename: Masahiko
authors.initials: M
authors.lastname: Miwa
authors.forename: Masahiro
authors.initials: M
authors.lastname: Kurosaka
authors.forename: Toshihiro
authors.initials: T
authors.lastname: Akisue
mesh_terms: D000279:Administration, Cutaneous; D000704:Analysis of Variance; D000818:Animals; D017209:Apoptosis / Q000187:drug effects*; D002118:Calcium / Q000378:metabolism; D002245:Carbon Dioxide / Q000008:administration & dosage / Q000494:pharmacology* / Q000627:therapeutic use; D053938:DNA Fragmentation / Q000187:drug effects; D017931:DNA Primers / Q000235:genetics; D005455:Fluorescent Antibody Technique; D051677:Histiocytoma, Malignant Fibrous / Q000188:drug therapy*; D006801:Humans; D015151:Immunoblotting; D008297:Male; D051379:Mice; D008807:Mice, Inbred BALB C; D008928:Mitochondria / Q000187:drug effects*; D000071248:Peroxisome Proliferator-Activated Receptor Gamma Coactivator 1-alpha; D060888:Real-Time Polymerase Chain Reaction; D015534:Trans-Activators / Q000378:metabolism*; D014157:Transcription Factors
chemical_list: D017931:DNA Primers; D000071248:Peroxisome Proliferator-Activated Receptor Gamma Coactivator 1-alpha; C485290:Ppargc1a protein, mouse; D015534:Trans-Activators; D014157:Transcription Factors; D002245:Carbon Dioxide; D002118:Calcium