Induction of claudin-4 by nonsteroidal anti-inflammatory drugs and its contribution to their chemopreventive effect.
Nonsteroidal anti-inflammatory drugs (NSAID) have shown chemopreventive effects in both preclinical and clinical studies; however, the precise molecular mechanism governing this response remains unclear. We used DNA microarray techniques to search for genes whose expression is induced by the NSAID indomethacin in human gastric carcinoma (AGS) cells. Among identified genes, we focused on those related to tight junction function (claudin-4, claudin-1, and occludin), particularly claudin-4. Induction of claudin-4 by indomethacin was confirmed at both mRNA and protein levels. NSAIDs, other than indomethacin (diclofenac and celecoxib), also induced claudin-4. All of the tested NSAIDs increased the intracellular Ca2+ concentration. Other drugs that increased the intracellular Ca2+ concentration (thapsigargin and ionomycin) also induced claudin-4. Furthermore, an intracellular Ca2+ chelator [1,2-bis(2-aminophenoxy)ethane-N,N,N',N'-tetraacetic acid] inhibited the indomethacin-dependent induction of claudin-4. These results strongly suggest that induction of claudin-4 by indomethacin is mediated through an increase in the intracellular Ca2+ concentration. Overexpression of claudin-4 in AGS cells did not affect cell growth or the induction of apoptosis by indomethacin. On the other hand, addition of indomethacin or overexpression of claudin-4 inhibited cell migration. Colony formation in soft agar was also inhibited. Suppression of claudin-4 expression by small interfering RNA restored the migration activity of AGS cells in the presence of indomethacin. Based on these results, we consider that the induction of claudin-4 and other tight junction-related genes by NSAIDs may be involved in the chemopreventive effect of NSAIDs through the suppression of anchorage-independent growth and cell migration.
Mima
Shinji
S
Graduate School of Medical and Pharmaceutical Sciences, Kumamoto University, Kumamoto, Japan.
Tsutsumi
Shinji
S
Ushijima
Hironori
H
Takeda
Miho
M
Fukuda
Ikue
I
Yokomizo
Kazumi
K
Suzuki
Keitarou
K
Sano
Kuniaki
K
Nakanishi
Tohru
T
Tomisato
Wataru
W
Tsuchiya
Tomofusa
T
Mizushima
Tohru
T
D000894:Anti-Inflammatory Agents, Non-Steroidal / Q000494:pharmacology*; D017209:Apoptosis / Q000187:drug effects; D014408:Biomarkers, Tumor / Q000378:metabolism*; D002118:Calcium / Q000378:metabolism; D002465:Cell Movement / Q000187:drug effects*; D018890:Chemoprevention; D062506:Claudin-4; D003114:Colony-Forming Units Assay; D004791:Enzyme Inhibitors / Q000494:pharmacology; D020869:Gene Expression Profiling; D006801:Humans; D007213:Indomethacin / Q000494:pharmacology*; D015759:Ionomycin / Q000494:pharmacology; D007476:Ionophores / Q000494:pharmacology; D008565:Membrane Proteins / Q000037:antagonists & inhibitors / Q000235:genetics / Q000378:metabolism*; D009369:Neoplasms / Q000235:genetics / Q000378:metabolism / Q000473:pathology; D020411:Oligonucleotide Array Sequence Analysis; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D034741:RNA, Small Interfering / Q000494:pharmacology; D019284:Thapsigargin / Q000494:pharmacology; D019108:Tight Junctions; D014407:Tumor Cells, Cultured
D000894:Anti-Inflammatory Agents, Non-Steroidal; D014408:Biomarkers, Tumor; C568157:CLDN4 protein, human; D062506:Claudin-4; D004791:Enzyme Inhibitors; D007476:Ionophores; D008565:Membrane Proteins; D012333:RNA, Messenger; D034741:RNA, Small Interfering; D015759:Ionomycin; D019284:Thapsigargin; D002118:Calcium; D007213:Indomethacin