Suppression of the malignant phenotype in pancreatic cancer by overexpression of phospholipid hydroperoxide glutathione peroxidase.
Phospholipid glutathione peroxidase (PhGPx) reduces lipid hydroperoxides generated in biomembranes and also uses a wide range of reducing cofactors in addition to glutathione. PhGPx is synthesized as a mitochondrial PhGPx form (L-form) and as a nonmitochondrial PhGPx form (S-form). Our aims were to determine whether overexpression of PhGPx altered pancreatic tumor cell behavior. Pancreatic cancer cell lines were found by Western blotting to have diminished levels of PhGPx-immunoreactive protein compared with normal human pancreas. To normalize the levels of this protein, PhGPx was overexpressed in MIA PaCa-2 and AsPC-1 human pancreatic cancer cells by infection with an adenovirus-PhGPx L-form construct (AdPhGPx- L-form) (0-200 MOI) or with an adenovirus-PhGPx S-form construct (AdPhGPx-S-form) (0-200 MOI), and cell growth, plating efficiency, and growth in soft agar were determined. Pancreatic cancer cells were also injected subcutaneously into nude mice and tumor volume was calculated. Single direct injections of the adenoviral- PhGPx constructs were made into preestablished tumors. In vitro, AdPhGPx-S-form demonstrated 80% tumor growth inhibition, whereas AdPhGPx-L-form demonstrated 95% tumor growth inhibition. Ad- PhGPx-L-form or AdPhGPx-S-form also decreased plating efficiency and growth in soft agar. AdPhGPx-Lform decreased in vivo tumor growth to a greater extent than did AdPhGPx-S-form. Because of the growthinhibitory effects of PhGPx, lipid hydroperoxides may play an important role in the growth of pancreatic cancer.
Liu
Jingru
J
Department of Radiation Oncology, University of Iowa College of Medicine, and Holden Comprehensive Cancer Center, Iowa City, IA 52242, USA.
Du
Juan
J
Zhang
Yuping
Y
Sun
Wenqing
W
Smith
Brian J
BJ
Oberley
Larry W
LW
Cullen
Joseph J
JJ
D000256:Adenoviridae / Q000235:genetics; D000818:Animals; D002455:Cell Division; D002460:Cell Line; D004305:Dose-Response Relationship, Drug; D005260:Female; D015971:Gene Expression Regulation, Enzymologic; D018014:Gene Transfer Techniques; D005979:Glutathione Peroxidase / Q000032:analysis / Q000096:biosynthesis* / Q000378:metabolism; D006801:Humans; D016014:Linear Models; D051379:Mice; D008819:Mice, Nude; D009368:Neoplasm Transplantation; D009369:Neoplasms; D010179:Pancreas / Q000201:enzymology / Q000254:growth & development / Q000473:pathology; D010190:Pancreatic Neoplasms / Q000201:enzymology* / Q000473:pathology / Q000628:therapy*; D010641:Phenotype; D000080662:Phospholipid Hydroperoxide Glutathione Peroxidase; D014161:Transduction, Genetic
D000080662:Phospholipid Hydroperoxide Glutathione Peroxidase; D005979:Glutathione Peroxidase