title: Platelet-type 12-lipoxygenase induces MMP9 expression and cellular invasion via activation of PI3K/Akt/NF-κB.
abstract: Prostate cancer is the most frequently diagnosed cancer and the second leading cause of death in males in the United States. Using human prostate cancer specimens, the authors have previously shown that elevated expression levels of 12-lipoxygenase (12-LOX) occurred more frequently in advanced stage, high-grade prostate cancer, suggesting that 12-LOX expression is associated with carcinoma progression and invasion. Previous reports from their group and others have shown that 12-LOX is a positive modulator of invasion and metastasis; however, the mechanism remains unclear. In this work, a new link between 12-LOX and the matrix metalloproteinase 9 (MMP9) in prostate cancer angiogenesis is reported. This study demonstrated that overexpression of 12-LOX in prostate cancer PC-3 cells resulted in elevated expression of MMP9 mRNA, protein and secretion. Exogenous addition of 12(S)-hydroxy eicosatetraenoic acid, the sole and stable end product of arachidonic acid metabolism by 12-LOX, is able to increase MMP9 expression in wild-type PC-3 cells. Furthermore, using pharmacological and genetic inhibition approaches, it was found that 12-LOX activates phosphoinositol 3 kinase (PI3K)/Akt, which results in nuclear factor-kappa B (NF-κB)-driven MMP9 expression, ensuing in enhanced chemoattraction of endothelial cells. Specific inhibitors of 12-LOX, PI3K or NF-κB inhibited MMP9 expression in 12-LOX-expressing PC-3 cells and resulted in the blockade of the migratory ability of endothelial cells. In summary, the authors have identified a new pathway by which overexpression of 12-LOX in prostate cancer cells leads to augmented production of MMP9 via activation of PI3K/Akt/NF-κB signaling. The role of 12-LOX-mediated MMP9 secretion in endothelial cell migration may account for the proangiogenic function of 12-LOX in prostate cancer.
authors.affiliation: Department of Pathology, Wayne State University School of Medicine, Detroit, MI 48202, USA.
authors.forename: Ashok-kumar
authors.initials: AK
authors.lastname: Dilly
authors.forename: Prasanna
authors.initials: P
authors.lastname: Ekambaram
authors.forename: Yande
authors.initials: Y
authors.lastname: Guo
authors.forename: Yinlong
authors.initials: Y
authors.lastname: Cai
authors.forename: Stephanie C
authors.initials: SC
authors.lastname: Tucker
authors.forename: Rafael
authors.initials: R
authors.lastname: Fridman
authors.forename: Mustapha
authors.initials: M
authors.lastname: Kandouz
authors.forename: Kenneth V
authors.initials: KV
authors.lastname: Honn
mesh_terms: D001092:Arachidonate 12-Lipoxygenase / Q000378:metabolism*; D002465:Cell Movement; D042783:Endothelial Cells / Q000378:metabolism; D004789:Enzyme Activation; D015972:Gene Expression Regulation, Neoplastic; D006801:Humans; D006893:Hydroxyeicosatetraenoic Acids / Q000494:pharmacology; D008297:Male; D020780:Matrix Metalloproteinase 9 / Q000096:biosynthesis* / Q000235:genetics / Q000378:metabolism; D016328:NF-kappa B / Q000235:genetics / Q000378:metabolism*; D009361:Neoplasm Invasiveness; D009389:Neovascularization, Pathologic; D019869:Phosphatidylinositol 3-Kinases / Q000378:metabolism*; D011471:Prostatic Neoplasms / Q000098:blood supply / Q000378:metabolism*; D051057:Proto-Oncogene Proteins c-akt / Q000378:metabolism; D034622:RNA Interference; D012333:RNA, Messenger / Q000096:biosynthesis; D034741:RNA, Small Interfering; D015398:Signal Transduction; D014407:Tumor Cells, Cultured
chemical_list: D006893:Hydroxyeicosatetraenoic Acids; D016328:NF-kappa B; D012333:RNA, Messenger; D034741:RNA, Small Interfering; D001092:Arachidonate 12-Lipoxygenase; D019869:Phosphatidylinositol 3-Kinases; D051057:Proto-Oncogene Proteins c-akt; C579270:MMP9 protein, human; D020780:Matrix Metalloproteinase 9
keywords: 12-lipoxygenase; MMP9; NF-κB; angiogenesis; matrix metalloproteinase; prostate cancer