PNNL

Abstract

Moving from macro-scale preparative systems in proteomics to micro- and nano-technologies offers researchers the ability to deeply profile smaller numbers of cells that are more likely to be encountered in clinical settings. Herein a recently developed microscale proteomic method, Microdroplet Processing in One pot for Trace Samples (microPOTS), was employed to identify proteomic changes in ~200 Barrett's oesophageal cells following physiologic and radiation stress exposure. From this small population of cells, microPOTS confidently identified >1500 protein groups, and achieved a high reproducibility with a Pearson’s correlation coefficient value of R>0.9 and over 50% protein overlap from replicates. A Barrett’s cell line model treated with either lithocholic acid (LCA) or X-ray had 25 (e.g. ACBP, RALY, CSRP1, H14, RIR2, ESTD) and 22 (e.g. HNRL2, F120A, GSHR, S100P, FKBP3, AGR2) overexpressed proteins, respectively, compared to the untreated set. These results demonstrate the ability of microPOTS to routinely identify and quantify differentially expressed proteins from limited numbers of cells. Data are available via ProteomeXchange with identifier PXD020741.