Two-fold increased in cell positivity in SW620 (metastatic) as compared to SW480 (primary). Abbreviations: membrane metallo-endopeptidase, MME; cutaneous lymphocyte antigen, CLA; mucin 1, MUC-1. *, Antigen was not two-fold increased by comparison of mean fluorescence intensities; however, differences in autofluorescence between cell lines limited the applicability of this analysis (Table S4). doi:10.1371/journal.pone.0053015.tCD3* CD95/FASR CD8b* CD33* CDw93* CD209/DC-SIGNRNA transcripts and outfitted polypeptides caution against using this filter as an ultimate determinant for selection of TAAs [5]. Rather, we favor the validation of informational content of TAAs on the basis of additional protein-level assays across a larger number of patient samples (e.g. immunohistochemistry on tissue microarrays). We validated integrin a6 in patient biopsies as a candidate tumor biomarker culled from our panel of antibodies. Further work will be necessary to address the clinical utility for integrin a6 and other identified Pictilisib web surface antigens in tumor cell detection and therapy design. Our results profiling human colon cancer cell lines expand upon those by Zhou et al. that also used a multiplexed antibody array [30?2]. Their study utilized a slide-based printed antibody arrayCD45RA* CD91/LRP-1 CD79b* CD153* CD130/gp130 CD337/NCR3* CD100/SEMA4D CD193/CCR3* CD271/LNGFR CD181/IL8RA* CD6* CD243/P-gp* CD61/Integrin b3* CD75* CD107b* CD108 CD54/ICAM1 CDFigure 4. CD10 expression in SW480 versus SW620. Histogram plots from antibody array for the CD10 antigen in SW480 (A) and SW620 (B). Red indicates isotype control while the blue line is staining for CD10. The number in the top left is the cell positivity. There is a clear shift from a small shoulder population in SW480 to complete binding in SW620 cells. C) Immunoblotting for CD10 confirms the strong change in CD10 expression. doi:10.1371/journal.pone.0053015.gAntibody array results showing surface antigens that were at least two-fold decreased in cell positivity in SW620 (metastatic) as compared to SW480 (primary). Abbreviations: epidermal GDC-0152 web growth factor receptor, EGFR; neural cell adhesion molecule, NCAM; C-X-C chemokine receptor 4, CXCR4; selectin P ligand, SELPLG; urokinase receptor, UPAR; FAS receptor, FasR; dendritic cellspecific intercellular adhesion molecule-3-grabbing non-integrin, DC-SIGN; low density lipoprotein receptor related protein 1, LRP1; glycoprotein 130, gp130; natural cytotoxicity triggering receptor 3, NCR3; semaphorin-4D, SEMA4D; C-C chemokine receptor 3, CCR3; low affinity nerve growth factor receptor; LNGFR; interleukin 8 receptor alpha, IL8RA; P-glycoprotein, P-gp; intercellular adhesion molecule 1, ICAM1. *, Antigen was not two-fold decreased by comparison of mean fluorescence intensities (Table S4). doi:10.1371/journal.pone.0053015.tMultiplexed FACS Antibody Array in Colon CancerTable 4. Expression of surface stem cell markers.EpCAM+ SW480 SW620 HCT116 92.3 99.9 95.EpCAM+CD44+ 64.9 61.0 95.EpCAM+CD133+ 0.70 57.4 85.EpCAM+CD44+CD133+ 0.50 40.4 85.Expression of putative surface cancer stem cell markers ( of live cells) in colon cancer cell lines as detected by multicolor flow cytometry. doi:10.1371/journal.pone.0053015.t(DotScanTM) with coverage of 122 cell surface markers. We found consistent signals with most, but not all, of their antibodies reacting with SW480 and SW620 cell lines, which may be attributable to sample preparation or analysis technique. In contrast to the DotSca.Two-fold increased in cell positivity in SW620 (metastatic) as compared to SW480 (primary). Abbreviations: membrane metallo-endopeptidase, MME; cutaneous lymphocyte antigen, CLA; mucin 1, MUC-1. *, Antigen was not two-fold increased by comparison of mean fluorescence intensities; however, differences in autofluorescence between cell lines limited the applicability of this analysis (Table S4). doi:10.1371/journal.pone.0053015.tCD3* CD95/FASR CD8b* CD33* CDw93* CD209/DC-SIGNRNA transcripts and outfitted polypeptides caution against using this filter as an ultimate determinant for selection of TAAs [5]. Rather, we favor the validation of informational content of TAAs on the basis of additional protein-level assays across a larger number of patient samples (e.g. immunohistochemistry on tissue microarrays). We validated integrin a6 in patient biopsies as a candidate tumor biomarker culled from our panel of antibodies. Further work will be necessary to address the clinical utility for integrin a6 and other identified surface antigens in tumor cell detection and therapy design. Our results profiling human colon cancer cell lines expand upon those by Zhou et al. that also used a multiplexed antibody array [30?2]. Their study utilized a slide-based printed antibody arrayCD45RA* CD91/LRP-1 CD79b* CD153* CD130/gp130 CD337/NCR3* CD100/SEMA4D CD193/CCR3* CD271/LNGFR CD181/IL8RA* CD6* CD243/P-gp* CD61/Integrin b3* CD75* CD107b* CD108 CD54/ICAM1 CDFigure 4. CD10 expression in SW480 versus SW620. Histogram plots from antibody array for the CD10 antigen in SW480 (A) and SW620 (B). Red indicates isotype control while the blue line is staining for CD10. The number in the top left is the cell positivity. There is a clear shift from a small shoulder population in SW480 to complete binding in SW620 cells. C) Immunoblotting for CD10 confirms the strong change in CD10 expression. doi:10.1371/journal.pone.0053015.gAntibody array results showing surface antigens that were at least two-fold decreased in cell positivity in SW620 (metastatic) as compared to SW480 (primary). Abbreviations: epidermal growth factor receptor, EGFR; neural cell adhesion molecule, NCAM; C-X-C chemokine receptor 4, CXCR4; selectin P ligand, SELPLG; urokinase receptor, UPAR; FAS receptor, FasR; dendritic cellspecific intercellular adhesion molecule-3-grabbing non-integrin, DC-SIGN; low density lipoprotein receptor related protein 1, LRP1; glycoprotein 130, gp130; natural cytotoxicity triggering receptor 3, NCR3; semaphorin-4D, SEMA4D; C-C chemokine receptor 3, CCR3; low affinity nerve growth factor receptor; LNGFR; interleukin 8 receptor alpha, IL8RA; P-glycoprotein, P-gp; intercellular adhesion molecule 1, ICAM1. *, Antigen was not two-fold decreased by comparison of mean fluorescence intensities (Table S4). doi:10.1371/journal.pone.0053015.tMultiplexed FACS Antibody Array in Colon CancerTable 4. Expression of surface stem cell markers.EpCAM+ SW480 SW620 HCT116 92.3 99.9 95.EpCAM+CD44+ 64.9 61.0 95.EpCAM+CD133+ 0.70 57.4 85.EpCAM+CD44+CD133+ 0.50 40.4 85.Expression of putative surface cancer stem cell markers ( of live cells) in colon cancer cell lines as detected by multicolor flow cytometry. doi:10.1371/journal.pone.0053015.t(DotScanTM) with coverage of 122 cell surface markers. We found consistent signals with most, but not all, of their antibodies reacting with SW480 and SW620 cell lines, which may be attributable to sample preparation or analysis technique. In contrast to the DotSca.