Differential toll-like receptor 3 (TLR3) expression and apoptotic response to TLR3 agonist in human neuroblastoma cells
<p>Abstract</p> <p>Background</p> <p>Toll-like receptor-3 (TLR-3) is a critical component of innate immune system against dsRNA viruses and is expressed in the central nervous system. However, it remains unknown whether TLR3 may serve as a therapeutic target in human ne...
| Main Authors: | , , , , , , , , |
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| Format: | Article |
| Language: | English |
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BMC
2011-08-01
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| Series: | Journal of Biomedical Science |
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| Online Access: | http://www.jbiomedsci.com/content/18/1/65 |
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| author | Du Yung-Ying Wu Chia-Ling Huang Chao-Cheng Chuang Hui-Ching Chuang Jiin-Haur Kung Mei-Lang Chen Chih-Hao Chen San-Cher Tai Ming-Hong |
| author_facet | Du Yung-Ying Wu Chia-Ling Huang Chao-Cheng Chuang Hui-Ching Chuang Jiin-Haur Kung Mei-Lang Chen Chih-Hao Chen San-Cher Tai Ming-Hong |
| author_sort | Du Yung-Ying |
| collection | DOAJ |
| description | <p>Abstract</p> <p>Background</p> <p>Toll-like receptor-3 (TLR-3) is a critical component of innate immune system against dsRNA viruses and is expressed in the central nervous system. However, it remains unknown whether TLR3 may serve as a therapeutic target in human neuroblastoma (NB).</p> <p>Methods</p> <p>TLR3 expression in human NB samples was examined by immunohistochemical analysis. Quantitative RT-PCR and western blot was used to determine TLR3 expression in three human NB cell lines. The effect of TLR3 agonist, polyinosinic-polycytidylic acid (poly(I:C)), on the growth of human NB cells was evaluated by WST-1 cell proliferation assay, flow cytometry analysis, and immunoblot analysis. Blockade of TLR3 signaling was achieved using TLR3 neutralizing antibody, small interference RNA, and 2-aminopurine (2-AP), an inhibitor of protein kinase R (PKR), an interferon-induced, double-stranded RNA-activated protein kinase.</p> <p>Results</p> <p>In immunohistochemical studies, TLR3 mainly expressed in the cytoplasm of ganglion cells and in some neuroblastic cells, but not in the stromal cells in human NB tissues. Among three human NB cell lines analyzed, TLR3 was significantly up-regulated in SK-N-AS cells at mRNA and protein level compared with other two low TLR3- expressing NB cells. Treatment with poly(I:C) elicited significant growth inhibition and apoptosis only in high TLR3-expressing SK-N-AS cells, but not in low TLR3-expressing SK-N-FI and SK-N-DZ cells. Moreover, poly(I:C) treatment significantly stimulated the activities of PKR, interferon regulatory factor 3 (IRF-3) and caspase-3 in SK-N-AS cells. Application of TLR3 neutralizing antibody or small interference RNA (siRNA) reduced the poly(I:C)-induced inhibition of cell proliferation and apoptosis in SK-N-AS cells. On the contrary, ectopic TLR3 expression enhanced the sensitivity of low TLR3-expressing NB cells to poly(I:C). Finally, application of 2-AP attenuated the poly(I:C)-induced IRF-3 and caspase-3 activation in SK-N-AS cells.</p> <p>Conclusion</p> <p>The present study demonstrates that TLR3 is expressed in a subset of NB cells. Besides, TLR3/PKR/IRF-3/capase-3 pathway is implicated in the selective cytotoxicity of TLR3 agonist towards high TLR3-expressing NB cells.</p> |
| first_indexed | 2024-12-18T14:08:09Z |
| format | Article |
| id | doaj.art-8714f7c2c4f64d5db1d18aa7297a60dc |
| institution | Directory Open Access Journal |
| issn | 1021-7770 1423-0127 |
| language | English |
| last_indexed | 2024-12-18T14:08:09Z |
| publishDate | 2011-08-01 |
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| spelling | doaj.art-8714f7c2c4f64d5db1d18aa7297a60dc2022-12-21T21:05:12ZengBMCJournal of Biomedical Science1021-77701423-01272011-08-011816510.1186/1423-0127-18-65Differential toll-like receptor 3 (TLR3) expression and apoptotic response to TLR3 agonist in human neuroblastoma cellsDu Yung-YingWu Chia-LingHuang Chao-ChengChuang Hui-ChingChuang Jiin-HaurKung Mei-LangChen Chih-HaoChen San-CherTai Ming-Hong<p>Abstract</p> <p>Background</p> <p>Toll-like receptor-3 (TLR-3) is a critical component of innate immune system against dsRNA viruses and is expressed in the central nervous system. However, it remains unknown whether TLR3 may serve as a therapeutic target in human neuroblastoma (NB).</p> <p>Methods</p> <p>TLR3 expression in human NB samples was examined by immunohistochemical analysis. Quantitative RT-PCR and western blot was used to determine TLR3 expression in three human NB cell lines. The effect of TLR3 agonist, polyinosinic-polycytidylic acid (poly(I:C)), on the growth of human NB cells was evaluated by WST-1 cell proliferation assay, flow cytometry analysis, and immunoblot analysis. Blockade of TLR3 signaling was achieved using TLR3 neutralizing antibody, small interference RNA, and 2-aminopurine (2-AP), an inhibitor of protein kinase R (PKR), an interferon-induced, double-stranded RNA-activated protein kinase.</p> <p>Results</p> <p>In immunohistochemical studies, TLR3 mainly expressed in the cytoplasm of ganglion cells and in some neuroblastic cells, but not in the stromal cells in human NB tissues. Among three human NB cell lines analyzed, TLR3 was significantly up-regulated in SK-N-AS cells at mRNA and protein level compared with other two low TLR3- expressing NB cells. Treatment with poly(I:C) elicited significant growth inhibition and apoptosis only in high TLR3-expressing SK-N-AS cells, but not in low TLR3-expressing SK-N-FI and SK-N-DZ cells. Moreover, poly(I:C) treatment significantly stimulated the activities of PKR, interferon regulatory factor 3 (IRF-3) and caspase-3 in SK-N-AS cells. Application of TLR3 neutralizing antibody or small interference RNA (siRNA) reduced the poly(I:C)-induced inhibition of cell proliferation and apoptosis in SK-N-AS cells. On the contrary, ectopic TLR3 expression enhanced the sensitivity of low TLR3-expressing NB cells to poly(I:C). Finally, application of 2-AP attenuated the poly(I:C)-induced IRF-3 and caspase-3 activation in SK-N-AS cells.</p> <p>Conclusion</p> <p>The present study demonstrates that TLR3 is expressed in a subset of NB cells. Besides, TLR3/PKR/IRF-3/capase-3 pathway is implicated in the selective cytotoxicity of TLR3 agonist towards high TLR3-expressing NB cells.</p>http://www.jbiomedsci.com/content/18/1/65neuroblastomatoll-like receptor 3poly(I:C)apoptosis |
| spellingShingle | Du Yung-Ying Wu Chia-Ling Huang Chao-Cheng Chuang Hui-Ching Chuang Jiin-Haur Kung Mei-Lang Chen Chih-Hao Chen San-Cher Tai Ming-Hong Differential toll-like receptor 3 (TLR3) expression and apoptotic response to TLR3 agonist in human neuroblastoma cells Journal of Biomedical Science neuroblastoma toll-like receptor 3 poly(I:C) apoptosis |
| title | Differential toll-like receptor 3 (TLR3) expression and apoptotic response to TLR3 agonist in human neuroblastoma cells |
| title_full | Differential toll-like receptor 3 (TLR3) expression and apoptotic response to TLR3 agonist in human neuroblastoma cells |
| title_fullStr | Differential toll-like receptor 3 (TLR3) expression and apoptotic response to TLR3 agonist in human neuroblastoma cells |
| title_full_unstemmed | Differential toll-like receptor 3 (TLR3) expression and apoptotic response to TLR3 agonist in human neuroblastoma cells |
| title_short | Differential toll-like receptor 3 (TLR3) expression and apoptotic response to TLR3 agonist in human neuroblastoma cells |
| title_sort | differential toll like receptor 3 tlr3 expression and apoptotic response to tlr3 agonist in human neuroblastoma cells |
| topic | neuroblastoma toll-like receptor 3 poly(I:C) apoptosis |
| url | http://www.jbiomedsci.com/content/18/1/65 |
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