Nano-LC-orbitrap MS/MS-based quantitative proteomics and transpcriptomics for uncovering the mechanisms of action of rosemary bioactives in colon cancer: a new foodomics approach

Resumen del trabajo presentado al 43rd Annual North American Meeting of the Federation of Analytical Chemistry and Spectroscopy Societies: "Great Scientific Exchange", celebrado en Minneapolis, Minnesota (USA) del 18 al 23 de septiembre de 2016.Recently, Foodomics has demonstrated to be a useful strategy to cover the identification of a wide range of molecular changes induced by rosemary compounds in in vitro cell models. Comprehensive transcriptomic and metabolomic analyses helped on identifying global changes induced by rosemary polyphenols on different cancer cell lines. In this work, a proteomics strategy based on nano-liquid chromatography-tandem mass spectrometry (nano-LC-MS/MS) using an Orbitrap high-resolution mass spectrometer together with stable isotope dimethyl labeling (DML) is applied to quantitatively examine relative changes in the protein fraction of human colon cancer cells treated with different concentrations of rosemary polyphenols (carnosic acid, carnosol, and a polyphenol-enriched rosemary extract) over the time. This proteomics approach provided extra confirmation for microarray data and new valuable data that allows gaining more insight into the biological processes orchestrating the response of HT-29 cells to rosemary polyphenols exposure. In addition, the causal analytic tool, UR analysis, based on IPA algorithm and Ingenuity Knowledge Base, helped on elucidating the upstream regulatory molecules and associated mechanism to the observed protein changes. Furthermore, examination of our data revealed that each rosemary polyphenol affects protein homeostasis by different mechanisms. Carnosic acid treatment induced the expression of proteins involved in the unfolded protein response in a concentration dependent manner reflecting accumulation of misfolded proteins in the endoplasmic reticulum (ER), whereas carnosol directly inhibits chymotrypsin-like activity of the 20S proteasome. The presented unbiased proteome-wide approach has shown to be a powerful tool that reveals differences in the mechanisms of action of two related bioactive diterpenes against colon cancer cells proliferation.Peer Reviewe