Detection of breast cancer biomarkers in nipple aspirate fluid by SELDI-TOF and their identification by combined liquid chromatography-tandem mass spectrometry.

Screening mammography is the most effective tool available for breast cancer detection. While screening mammography saves lives, it has intrinsic problems that limit further improvement. We hypothesize that protein biomarkers in nipple aspirate fluid (NAF) may separate the cancer from the non-cancer state, and therefore can be used for breast cancer detection. In this study the proteins in NAF were analyzed by surface-enhanced laser desorption ionization coupled to time-of-flight mass spectrometry (SELDI-TOF) in the m/z 5,000-85,000 range. Two methods were used to normalize spectra. Then differentially expressed signals that separate cancer from non-cancer conditions were selected by two specifically developed statistical algorithms. Proteins of interest were identified by combined liquid chromatography-tandem mass spectrometry. A set of 8 markers were identified which collectively gave 63% sensitivity, 89% specificity and 76% accuracy for distinguishing cancer from non-cancer. Further improvements in the specificity and sensitivity of this strategy could come from the development of methods for more precise quantification of the biomarkers of interest and also from focusing on the low abundant components that are not evident when unfractionated NAF is analyzed directly.

Glucocorticoid-attenuated response genes induced in the lung during endotoxemia.

Cytokines and other mediators whose induction in inflammatory lung disease is attenuated by glucocorticoids are potential targets for development of selective anti-inflammatory treatments. We refer to genes with these regulatory characteristics as glucocorticoid-attenuated response genes, or GARGs. Systematic identification of GARGs has not been attempted previously in vivo. Using an endotoxemia model in adrenalectomized mice, we constructed a subtracted lung library enriched in endotoxemia-induced genes and identified candidate GARGs by differential hybridization screening. Northern analysis confirmed induction in the lung during endotoxemia and attenuation by glucocorticoids of 36 genes of diverse types. The majority were genes of unknown function not previously implicated in the pulmonary response to inflammation, including a new member of a 2'-5'-oligoadenylate synthetase-like family and a novel lung inducible Neuralized-related C3HC4 RING protein. Our results suggest that a full understanding of glucocorticoid effects on lung inflammation will require elucidation of the roles of an extensive network of glucocorticoid-modulated genes.