Reactive oxygen species stimulates epithelial mesenchymal transition in normal human epidermal keratinocytes via TGF-beta secretion.
Epithelial to mesenchymal transition (EMT) plays an important role in tumor progression, and is an early step in carcinogenesis. Although reactive oxygen species (ROS) are known to be implicated in EMT in many tumor cell types, its exact role in EMT initiation in normal human cells, especially epidermal keratinocytes (NHEKs), remains unknown. To clarify whether ROS induce EMT in NHEKs, and to establish how ROS regulate EMT, we examined the effect of hydrogen peroxide (H(2)O(2)) on the expression of molecules involved in EMT and cell morphology in NHEKs. H(2)O(2) altered the expression of EMT biomarkers, including downregulation of epithelial cadherin and upregulation of α-smooth muscle actin, through a transcriptional modulator, Snail1. H(2)O(2) also induced epithelial to fibroblast-like morphological changes, together with upregulation of EMT biomarkers, and promoted phosphorylation of ERK1/2 and JNK in a time-dependent manner. Interestingly, H(2)O(2) stimulated the expression and secretion of TGF-β1 in NHEKs. Exogenous TGF-β1 also induced the expression of EMT biomarkers. In contrast, neutralizing antibody anti-TGF-β1 antibody or inhibitor of TGF-β receptor type I suppressed the expression of EMT biomarkers. Our results suggest that ROS stimulated TGF-β1 secretion and MAPK activation, resulting in EMT initiation in NHEKs.
Department of Physiological Science and Molecular Biology, Fukuoka Dental College, Sawara-ku, Fukuoka 8140193, Japan.
Teruhisa
T
Fukawa
Hiroshi
H
Kajiya
Satoru
S
Ozeki
Tetsuro
T
Ikebe
Koji
K
Okabe
D000199:Actins / Q000235:genetics / Q000378:metabolism; D001483:Base Sequence; D015415:Biomarkers / Q000378:metabolism; D015820:Cadherins / Q000235:genetics / Q000378:metabolism; D002478:Cells, Cultured; D017931:DNA Primers / Q000235:genetics; D058750:Epithelial-Mesenchymal Transition / Q000187:drug effects* / Q000235:genetics / Q000502:physiology*; D006801:Humans; D006861:Hydrogen Peroxide / Q000494:pharmacology*; D015603:Keratinocytes / Q000166:cytology / Q000187:drug effects* / Q000502:physiology*; D020935:MAP Kinase Signaling System / Q000187:drug effects; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D017382:Reactive Oxygen Species / Q000378:metabolism; D000071250:Snail Family Transcription Factors; D014157:Transcription Factors / Q000235:genetics / Q000378:metabolism; D016212:Transforming Growth Factor beta / Q000096:biosynthesis*; D015854:Up-Regulation / Q000187:drug effects
C541116:ACTA2 protein, human; D000199:Actins; D015415:Biomarkers; D015820:Cadherins; D017931:DNA Primers; D012333:RNA, Messenger; D017382:Reactive Oxygen Species; C000604407:SNAI1 protein, human; D000071250:Snail Family Transcription Factors; D014157:Transcription Factors; D016212:Transforming Growth Factor beta; D006861:Hydrogen Peroxide