Nitric oxide causes anoikis through attenuation of E-cadherin and activation of caspase-3 in human gastric carcinoma AZ-521 cells infected with Mycoplasma hyorhinis.
Mycoplasma hyorhinis (M. hyorhinis) infection leads cultured cells to various biological alterations in cell metabolism including apoptosis. Apoptosis induced by M. hyorhinis has mainly been considered to be due to mycoplasmal endonucleases. We previously reported that apoptosis in a human carcinoma cell line AZ-521 infected with M. hyorhinis was enhanced by addition of L-ascorbic acid to cell cultures. Since both L-ascorbic acid addition and M. hyorhinis infection activated cellular iNOS, we examined the hypothesis that nitric oxide (NO) exerts an apoptotic effect on M. hyorhinis-infected cells and down-regulates E-cadherin. In this study, we showed that M. hyorhinis infection activates iNOS mRNA synthesis, NO production, and caspase-3 activity and attenuates E-cadherin mRNA synthesis by quantitative real-time PCR, Griess assay and fluorescence caspase-3 detection. L-NAME decreased the numbers of apoptotic cells through inhibition caspase-3 activity. Our results indicate that NO causes anoikis throughout attenuation of E-cadherin and activation of caspase-3 in human gastric carcinoma cell line AZ-521 cells infected with M. hyorhinis.
Obara
Hisato
H
Department of Veterinary Microbiology, Faculty of Agriculture, Iwate University, Morioka, Japan.
Harasawa
Ryô
R
D023102:Anoikis / Q000187:drug effects*; D015820:Cadherins / Q000235:genetics / Q000378:metabolism*; D053148:Caspase 3 / Q000378:metabolism*; D045744:Cell Line, Tumor; D004789:Enzyme Activation; D006801:Humans; D009175:Mycoplasma Infections / Q000150:complications*; D045790:Mycoplasma hyorhinis; D009566:Nitrates / Q000378:metabolism; D009569:Nitric Oxide / Q000494:pharmacology*; D052247:Nitric Oxide Synthase Type II / Q000235:genetics; D009573:Nitrites / Q000378:metabolism; D020133:Reverse Transcriptase Polymerase Chain Reaction; D013274:Stomach Neoplasms / Q000201:enzymology / Q000378:metabolism*
D015820:Cadherins; D009566:Nitrates; D009573:Nitrites; D009569:Nitric Oxide; D052247:Nitric Oxide Synthase Type II; D053148:Caspase 3