Erythropoietin receptor expression in non-small cell lung carcinoma: a question of antibody specificity

Immunohistochemical studies on formalin-fixed, paraffin-embedded (FFPE) tissue utilizing polyclonal antibodies form the cornerstone of many reports claiming to demonstrate erythropoietin receptor (EPOR) expression in malignant tissue. Recently, Elliott et al. (Blood 2006;107:1892–1895) reported that the antibodies commonly used to detect EPOR expression also detect non-EPOR proteins, and that their binding to EPOR was severely abrogated by two synthetic peptides based on the sequence of heat shock protein (HSP) 70, HSP70-2, and HSP70-5. We have investigated the specificity of the C20 antibody for detecting EPOR expression in non-small cell lung carcinoma (NSCLC) utilizing tissue microarrays. A total of 34 cases were available for study. Antibody absorbed with peptide resulted in marked suppression of cytoplasmic staining compared with nonabsorbed antibody. Four tumors that initially showed a membranous pattern of staining retained this pattern with absorbed antibody. Positive membranous immunoreactivity was also observed in 6 of 30 tumors that originally showed a predominantly cytoplasmic pattern of staining. Using the C20 antibody for Western blots, we detected three main bands, at 100, 66, and 59 kDa. Preincubation with either peptide caused abolition of the 66-kDa band, which contains non-EPOR sequences including heat shock peptides. These results call into question the significance of previous immunohistochemical studies of EPOR expression in malignancy and emphasize the need for more specific anti-EPOR antibodies to define the true extent of EPOR expression in neoplastic tissue

Sex-specific clinical outcomes after treatment of left main coronary artery disease. A NOBLE substudy

Background: While female sex has been associated with worse outcomes following coronary revascularization, previous analyses in left main coronary artery (LMCA) disease have been conflicting. In addition, a signal that increased mortality may be specific to women treated with percutaneous coronary intervention (PCI) requires further investigation. Methods: Nordic-Baltic-British left main revascularization study (NOBLE) was a randomized trial comparing PCI to coronary artery bypass surgery (CABG) in patients with LMCA disease. The primary endpoint was a composite of all-cause mortality, nonprocedural myocardial infarction, repeat revascularization, and stroke (major adverse cardiovascular and cerebrovascular events [MACCE]). We report the 5-year sex-specific outcomes. Results: Of 1184 patients analyzed, 256 (22%) were female and 928 (78%) were male. There were no significant within-sex differences in baseline characteristics, disease location, or complexity between those treated with PCI and those with CABG. The 5-year MACCE rates were 29% and 15% in females and 28% and 20% in males treated with PCI and CABG, respectively. Within both sexes, there was an increased risk of MACCE with PCI compared with CABG, but no difference in all-cause mortality. On multivariate analysis, female sex was not an independent predictor of MACCE. Conclusions: Following the treatment of LMCA disease, long-term outcomes favored CABG over PCI in both sexes. Importantly, there was no difference in all-cause mortality in females or males at 5 ​years