Microarray analysis of genes associated with cell surface NIS protein levels in breast cancer
1 Integrated Biomedical Sciences Graduate Program, The Ohio State University, Columbus, Ohio 43210, USA
2 Department of Physiology and Cell Biology, The Ohio State University, Columbus, Ohio 43210, USA
3 Center for Biostatistics, The Ohio State University, Columbus, Ohio 43210, USA
4 Department of Anatomic Pathology, Mayo Clinic, Rochester, Minnesota 55901, USA
5 Department of Epidemiology and Biostatistics, University of Maryland, College Park, Maryland 20742, USA
6 Department of Pathology, Brigham and Women's Hospital, Harvard Medical School Boston, Massachusetts 02115, USA
7 Department of Biomedical Informatics, The Ohio State University, Columbus, Ohio 43210, USA
BMC Research Notes 2011, 4:397 doi:10.1186/1756-0500-4-397Published: 11 October 2011
Na+/I- symporter (NIS)-mediated iodide uptake allows radioiodine therapy for thyroid cancer. NIS is also expressed in breast tumors, raising potential for radionuclide therapy of breast cancer. However, NIS expression in most breast cancers is low and may not be sufficient for radionuclide therapy. We aimed to identify biomarkers associated with NIS expression such that mechanisms underlying NIS modulation in human breast tumors may be elucidated.
Published oligonucleotide microarray data within the National Center for Biotechnology Information Gene Expression Omnibus database were analyzed to identify gene expression tightly correlated with NIS mRNA level among human breast tumors. NIS immunostaining was performed in a tissue microarray composed of 28 human breast tumors which had corresponding oligonucleotide microarray data available for each tumor such that gene expression associated with cell surface NIS protein level could be identified.
Results and Discussion
NIS mRNA levels do not vary among breast tumors or when compared to normal breast tissues when detected by Affymetrix oligonucleotide microarray platforms. Cell surface NIS protein levels are much more variable than their corresponding NIS mRNA levels. Despite a limited number of breast tumors examined, our analysis identified cysteinyl-tRNA synthetase as a biomarker that is highly associated with cell surface NIS protein levels in the ER-positive breast cancer subtype.
Further investigation on genes associated with cell surface NIS protein levels within each breast cancer molecular subtype may lead to novel targets for selectively increasing NIS expression/function in a subset of breast cancers patients.