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dc.contributor.authorOztas, E.en_US
dc.contributor.authorAvci, M. E.en_US
dc.contributor.authorOzcan, A.en_US
dc.contributor.authorSayan, A. E.en_US
dc.contributor.authorTulchinsky, E.en_US
dc.contributor.authorYagci, T.en_US
dc.date.accessioned2016-02-08T09:56:37Z
dc.date.available2016-02-08T09:56:37Z
dc.date.issued2010en_US
dc.identifier.issn0014-4800
dc.identifier.urihttp://hdl.handle.net/11693/22183
dc.description.abstractSmad-interacting protein 1 (SIP1, also known as ZEB2) represses the transcription of E-cadherin and mediates epithelial-mesenchymal transition in development and tumor metastasis. Due to the lack of human SIP1-specific antibodies, its expression in human tumor tissues has not been studied in detail by immunohistochemistry. Hence, we generated two anti-SIP1 monoclonal antibodies, clones 1C6 and 6E5, with IgG1 and IgG2a isotypes, respectively. The specificity of these antibodies was shown by Western blotting studies using siRNA mediated downregulation of SIP1 and ZEB1 in a human osteosarcoma cell line. In the same context, we also compared them with 5 commercially available SIP1 antibodies. Antibody specificity was further verified in an inducible cell line system by immunofluorescence. By using both antibodies, we evaluated the tissue expression of SIP1 in paraffin-embedded tissue microarrays consisting of 22 normal and 101 tumoral tissues of kidney, colon, stomach, lung, esophagus, uterus, rectum, breast and liver. Interestingly, SIP1 predominantly displayed a cytoplasmic expression, while the nuclear localization of SIP1 was observed in only 6 cases. Strong expression of SIP1 was found in distal tubules of kidney, glandular epithelial cells of stomach and hepatocytes, implicating a co-expression of SIP1 and E-cadherin. Squamous epithelium of the esophagus and surface epithelium of colon and rectum were stained with moderate to weak intensity. Normal uterus, breast and lung tissues remained completely negative. By comparison with their normal tissues, we observed SIP1 overexpression in cancers of the kidney, breast, lung and uterus. However, SIP1 expression was found to be downregulated in tumors from colon, rectum, esophagus, liver and stomach tissues. Finally we did nuclear/cytoplasmic fractionation in 3 carcinoma cell lines and detected SIP1 in both fractions, nucleus being the dominant one. To our best knowledge, this is the first comprehensive immunohistochemical study of the expression of SIP1 in a series of human cancers. Our finding that SIP1 is not exclusively localized to nucleus suggests that the subcellular localization of SIP1 is regulated in normal and tumor tissues. These novel monoclonal antibodies may help elucidate the role of SIP1 in tumor development. © 2010 Elsevier Inc.en_US
dc.language.isoEnglishen_US
dc.source.titleExperimental and Molecular Pathologyen_US
dc.relation.isversionofhttp://dx.doi.org/10.1016/j.yexmp.2010.05.010en_US
dc.subjectImmunohistochemistryen_US
dc.subjectMonoclonal antibodiesen_US
dc.subjectMultiple tissue arraysen_US
dc.subjectSIP1/ZEB2en_US
dc.titleNovel monoclonal antibodies detect Smad-interacting protein 1 (SIP1) in the cytoplasm of human cells from multiple tumor tissue arraysen_US
dc.typeArticleen_US
dc.departmentDepartment of Molecular Biology and Geneticsen_US
dc.citation.spage182en_US
dc.citation.epage189en_US
dc.citation.volumeNumber89en_US
dc.citation.issueNumber2en_US
dc.identifier.doi10.1016/j.yexmp.2010.05.010en_US
dc.publisherElsevieren_US


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