Oxidant-sensitive transcription factor and cyclooxygenase-2 by Helicobacter pylori stimulation in human gastric cancer cells.
Helicobacter pylori (H. pylori) infection might activate nuclear factor-kappaB (NF-kappaB), an oxidant-sensitive transcription regulator of inducible expression of inflammatory genes such as cyclooxygenase-2 (COX-2). We studied the role of NF-kappaB on expression of COX-2 in H. pylori-stimulated gastric cancer cell lines by using antioxidants, glutathione (GSH), and N-acetylcysteine (NAC) as well as an NF-kappaB inhibitor, pyrrolidine dithiocarbamate (PDTC). Gastric adenocarcinoma cell lines derived from Caucasian (AGS) cells and Korean (SNU-484) cells were used to study the role of NF-kappaB on COX-2 expression by H. pylori. They were treated with GSH, NAC, or PDTC in the presence of H. pylori. mRNA expression and protein level for COX-2 were determined by Northern blot and RT-PCR analysis as well as Western blot analysis. NF-kappaB activation was examined by electrophoretic mobility shift assay. As a result, H. pylori induced a time-dependent expression of mRNA and protein for COX-2 via activation of NF-kappaB, which was inhibited by GSH, NAC, and PDTC in the cells. In conclusion, oxidant-sensitive transcription factor NF-kappaB may play a novel role in expression of COX-2 by H. pylori stimulation in gastric cancer cells.
Kim
Hyeyoung
H
Department of Pharmacology and Institute of Gastroenterology, Yonsei University College of Medicine, Seoul, Korea. kim626@yumc.yonsei.ac.kr
Lim
Joo Weon
JW
Seo
Jeong Yeon
JY
Kim
Kyung Hwan
KH
D000230:Adenocarcinoma / Q000473:pathology*; D000975:Antioxidants / Q000494:pharmacology; D015152:Blotting, Northern; D015153:Blotting, Western; D051546:Cyclooxygenase 2; D016481:Helicobacter Infections / Q000473:pathology*; D006801:Humans; D007527:Isoenzymes / Q000096:biosynthesis*; D008565:Membrane Proteins; D016328:NF-kappa B / Q000494:pharmacology*; D011451:Prostaglandin-Endoperoxide Synthases / Q000096:biosynthesis*; D012333:RNA, Messenger / Q000096:biosynthesis; D020133:Reverse Transcriptase Polymerase Chain Reaction; D013274:Stomach Neoplasms / Q000473:pathology*; D014407:Tumor Cells, Cultured
D000975:Antioxidants; D007527:Isoenzymes; D008565:Membrane Proteins; D016328:NF-kappa B; D012333:RNA, Messenger; D051546:Cyclooxygenase 2; C496540:PTGS2 protein, human; D011451:Prostaglandin-Endoperoxide Synthases