Mitochondrial targeting of a catalase transgene product by plasmid liposomes increases radioresistance in vitro and in vivo.
To determine whether increased mitochondrially localized catalase was radioprotective, a human catalase transgene was cloned into a small pSVZeo plasmid and localized to the mitochondria of 32D cl 3 cells by adding the mitochondrial localization sequence of MnSOD (mt-catalase). The cell lines 32D-Cat and 32D-mt-Cat had increased catalase biochemical activity as confirmed by Western blot analysis compared to the 32D cl 3 parent cells. The MnSOD-overexpressing 32D cl 3 cell line, 2C6, had decreased baseline catalase activity that was increased in 2C6-Cat and 2C6-mt-Cat subclonal cell lines. 32D-mt-Cat cells were more radioresistant than 32D-Cat cells, but both were radioresistant relative to 32D cl 3 cells. 2C6-mt-Cat cells but not 2C6-Cat cells were radioresistant compared to 2C6 cells. Intratracheal injection of the mt-catalase-plasmid liposome complex (mt-Cat-PL) but not the catalase-plasmid liposome complex (Cat-PL) increased the resistance of C57BL/6NHsd female mice to 20 Gy thoracic irradiation compared to MnSOD-plasmid liposomes. Thus mitochondrially targeted overexpression of the catalase transgene is radioprotective in vitro and in vivo.
Epperly
Michael W
MW
Department of Radiation Oncology, University of Pittsburgh Cancer Institute, Pittsburgh, Pennsylvania, USA.
Melendez
J A
JA
Zhang
Xichen
X
Nie
Suhua
S
Pearce
Linda
L
Peterson
James
J
Franicola
Darcy
D
Dixon
Tracy
T
Greenberger
Benjamin A
BA
Komanduri
Paavani
P
Wang
Hong
H
Greenberger
Joel S
JS
D000818:Animals; D002374:Catalase / Q000235:genetics / Q000502:physiology*; D002460:Cell Line; D002470:Cell Survival / Q000528:radiation effects; D005260:Female; D005978:Glutathione / Q000032:analysis; D005979:Glutathione Peroxidase / Q000032:analysis; D006801:Humans; D008081:Liposomes; D051379:Mice; D008810:Mice, Inbred C57BL; D008928:Mitochondria / Q000201:enzymology*; D010957:Plasmids; D011836:Radiation Tolerance; D013482:Superoxide Dismutase / Q000502:physiology; D019076:Transgenes
D008081:Liposomes; D002374:Catalase; D005979:Glutathione Peroxidase; D013482:Superoxide Dismutase; D005978:Glutathione