Association of gp91phox homolog Nox1 with anchorage-independent growth and MAP kinase-activation of transformed human keratinocytes.
Among five members of the NADPH oxidase (Nox) family, Nox1 confers mitogenic properties and is implicated to participate in the process of cell transformation. We have established two phenotypes of carcinogenesis model by ethanol treatment of human gingival keratinocytes immortalized with E6/E7 oncogenes of human papillomavirus type16: immortalized (EPI) nontransformed cells with epithelium-like morphology and more advanced transformed (FIB) cells with spindle fibroblastic-shape morphology. FIB membranes possessed a 63-kDa Nox1 protein at higher levels and exhibited 2.8-fold higher capability for superoxide and hydroxyl radical generation, compared with EPI membranes. Both EPI and FIB cells expressed more abundant Nox1 protein at a proliferating stage than that at a quiescent confluent phase. Immunofluorescence staining with an anti-Nox1 antibody showed that immunoreactive materials were distributed in the whole interior of both types of cells, while they were preferentially localized in the nuclei of FIB cells. Nuclei isolated from EPI and FIB cells contained a 63 kDa-Nox1 protein. Compared with EPI cells, FIB cells expressed elevated levels of Jun N-terminal kinase (JNK) and extracellular signal-regulated kinase proteins. Furthermore, JNK2 was constitutively phosphorylated in FIB cells. Together, our data strongly implicate Nox1 in redox-mediated signaling related to cellular activation of human keratinocytes at a more advanced stage of transformation.
Chamulitrat
Walee
W
Deutsches Krebsforschungszentrum, Department of Applied Tumorvirology, 69120 Heidelberg, Germany. Walee_Chamulitrat@med.uni-heidelberg.de
Schmidt
Rainer
R
Tomakidi
Pascal
P
Stremmel
Wolfgang
W
Chunglok
Warangkana
W
Kawahara
Tsukasa
T
Rokutan
Kazuhito
K
D002455:Cell Division / Q000235:genetics; D002461:Cell Line, Transformed; D002462:Cell Membrane / Q000235:genetics / Q000378:metabolism; D002467:Cell Nucleus / Q000235:genetics / Q000378:metabolism; D004789:Enzyme Activation; D005347:Fibroblasts / Q000166:cytology / Q000378:metabolism; D006801:Humans; D048031:JNK Mitogen-Activated Protein Kinases; D015603:Keratinocytes / Q000378:metabolism* / Q000473:pathology; D008562:Membrane Glycoproteins / Q000235:genetics* / Q000378:metabolism; D048056:Mitogen-Activated Protein Kinase 9; D020928:Mitogen-Activated Protein Kinases / Q000378:metabolism*; D009247:NADH, NADPH Oxidoreductases / Q000235:genetics / Q000378:metabolism*; D000074624:NADPH Oxidase 1; D000074662:NADPH Oxidase 2; D019255:NADPH Oxidases / Q000378:metabolism; D009856:Oncogene Proteins, Viral / Q000235:genetics; D050725:Papillomavirus E7 Proteins; D010766:Phosphorylation; D012333:RNA, Messenger / Q000378:metabolism; D012097:Repressor Proteins; D014410:Tumor Stem Cell Assay; D015854:Up-Regulation
C068651:E6 protein, Human papillomavirus type 16; D008562:Membrane Glycoproteins; D009856:Oncogene Proteins, Viral; D050725:Papillomavirus E7 Proteins; D012333:RNA, Messenger; D012097:Repressor Proteins; C059731:oncogene protein E7, Human papillomavirus type 16; D009247:NADH, NADPH Oxidoreductases; C056558:CYBB protein, human; D000074624:NADPH Oxidase 1; D000074662:NADPH Oxidase 2; D019255:NADPH Oxidases; D048056:Mitogen-Activated Protein Kinase 9; D048031:JNK Mitogen-Activated Protein Kinases; D020928:Mitogen-Activated Protein Kinases