title: Up-regulation of mitochondrial antioxidation signals in ovarian cancer cells with aggressive biologic behavior.
abstract: OBJECTIVE
  Recently, a high frequency of mutations in mitochondrial DNA (mtDNA) has been detected in ovarian cancer. To explore the alterations of proteins in mitochondria in ovarian cancer, a pair of human ovarian carcinoma cell lines (SKOV3/SKOV3.ip1) with different metastatic potentials was examined.
  
  
  METHODS
  Cancer cells SKOV3.ip1 were derived from the ascitic tumor cells of nude mice bearing a tumor of ovarian cancer cells SKOV3. SKOV3.ip1 exhibited a higher degree of migration potential than its paired cell line SKOV3. The proteins in the mitochondria of these two cells were isolated and separated by 2-D gel electrophoresis. The differently expressed proteins were extracted and identified using matrix assisted laser desorption ionisation/time-of-flight/time-of-flight (MALDI-TOF/TOF), and finally a selected protein candidate was further investigated by immunohistochemistry (IHC) method in nude mice bearing tumor tissues of these two cells.
  
  
  RESULTS
  A total of 35 spots with different expressions were identified between the two cells using 2D-polyacrylamide gel electrophoresis (PAGE) approach. Among them, 17 spots were detected only in either SKOV3 or SKOV3.ip1 cells. Eighteen spots expressed different levels, with as much as a three-fold difference between the two cells. Twenty spots were analyzed using MALDI-TOF/TOF, and 11 of them were identified successfully; four were known to be located in mitochondria, including superoxide dismutase 2 (SOD2), fumarate hydratase (FH), mitochondrial ribosomal protein L38 (MRPL38), and mRNA turnover 4 homolog (MRTO4). An increased staining of SOD2 was observed in SKOV3.ip1 over that of SKOV3 in IHC analysis.
  
  
  CONCLUSIONS
  Our results indicate that the enhanced antioxidation and metabolic potentials of ovarian cancer cells might contribute to their aggressive and metastatic behaviors. The underlying mechanism warrants further study.
authors.affiliation: Department of Obstetrics and Gynecology, People's Hospital, Peking University, Beijing, China. wangyue99992002@yahoo.com
authors.forename: Yue
authors.initials: Y
authors.lastname: Wang
authors.forename: Li
authors.initials: L
authors.lastname: Dong
authors.forename: Heng
authors.initials: H
authors.lastname: Cui
authors.forename: Dan-hua
authors.initials: DH
authors.lastname: Shen
authors.forename: Ying
authors.initials: Y
authors.lastname: Wang
authors.forename: Xiao-hong
authors.initials: XH
authors.lastname: Chang
authors.forename: Tian-yun
authors.initials: TY
authors.lastname: Fu
authors.forename: Xue
authors.initials: X
authors.lastname: Ye
authors.forename: Yuan-yang
authors.initials: YY
authors.lastname: Yao
mesh_terms: D000818:Animals; D000975:Antioxidants / Q000378:metabolism*; D045744:Cell Line, Tumor; D015180:Electrophoresis, Gel, Two-Dimensional; D005260:Female; D006801:Humans; D051379:Mice; D008819:Mice, Nude; D008928:Mitochondria / Q000378:metabolism*; D024101:Mitochondrial Proteins / Q000302:isolation & purification / Q000378:metabolism; D009361:Neoplasm Invasiveness; D009363:Neoplasm Proteins / Q000302:isolation & purification / Q000378:metabolism; D010051:Ovarian Neoplasms / Q000378:metabolism* / Q000503:physiopathology / Q000556:secondary; D020543:Proteome / Q000302:isolation & purification / Q000378:metabolism; D015398:Signal Transduction; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization; D013482:Superoxide Dismutase / Q000378:metabolism; D015854:Up-Regulation; D000099156:Superoxide Dismutase 2
chemical_list: D000975:Antioxidants; D024101:Mitochondrial Proteins; D009363:Neoplasm Proteins; D020543:Proteome; D013482:Superoxide Dismutase; D000099156:Superoxide Dismutase 2