Inhibition of Glycogen Phosphorylation Induces Changes in Cellular Proteom and Signaling Pathways in MIA Pancreatic Cancer Cells
Pancreas. 41(3):397-408, April 2012.
Objectives: Novel quantitative proteomic approaches were used to study the effects of inhibition of glycogen phosphorylase on proteome and signaling pathways in MIA PaCa-2 pancreatic cancer cells.
Methods: We performed quantitative proteomic analysis in MIA PaCa-2 cancer cells treated with a stratified dose of CP-320626 (5-chloro-1H-indole-2-carboxylic acid [1-(4-fuorobenzyl)-2-(4-hydroxypiperidin-1-yl)-2 oxoethyl] amide) (25, 50, and 100 μM). The effect of metabolic inhibition on cellular protein turnover dynamics was also studied using the modified SILAC (stable isotope labeling with amino acids in cell culture) method.
Results: A total of 22 protein spots and 4 phosphoprotein spots were quantitatively analyzed. We found that dynamic expression of total proteins and phosphoproteins was significantly changed in MIA PaCa-2 cells treated with an incremental dose of CP-320626. Functional analyses suggested that most of the proteins differentially expressed were in the pathways of mitogen-activated protein kinase/extracellular signal–regulated kinase and tumor necrosis factor α/nuclear factor κB.
Conclusions: Signaling pathways and metabolic pathways share many common cofactors and substrates forming an extended metabolic network. The restriction of substrate through 1 pathway such as inhibition of glycogen phosphorylation induces pervasive metabolomic and proteomic changes manifested in protein synthesis, breakdown, and posttranslational modification of signaling molecules. Our results suggest that quantitative proteomic is an important approach to understand the interaction between metabolism and signaling pathways.
Abbreviations: MALDI – matrix-assisted laser desorption ionization, TOF/TOF MS – time-of-flight/time-of-flight mass spectrometry, 2-DE – 2-dimensional electrophoresis, PMF – peptide mass fingerprinting, CP-320626 – 5-chloro-1H-indole-2-carboxylic acid [1-(4-fuorobenzyl)-2-(4-hydroxypiperidin-1-yl)-2 oxoethyl]amide
The latest issue of the Pancreas can be found here.
Tracer-based metabolomics: concepts and practices.
Clin Biochem. 2010 Nov;43(16-17):1269-77. Epub 2010 Aug 14.
Tracer-based metabolomics is a systems biology tool that combines advances in tracer methodology for physiological studies, high throughput “-omics” technologies and constraint based modeling of metabolic networks. It is different from the commonly known metabolomics or metabonomics in that it is a targeted approach based on a metabolic network model in cells. Because of its complexity, it is the least understood among the various “-omics.” In this review, the development of concepts and practices of tracer-based metabolomics is traced from the early application of radioactive isotopes in metabolic studies to the recent application of stable isotopes and isotopomer analysis using mass spectrometry; and from the modeling of biochemical reactions using flux analysis to the recent theoretical formulation of the constraint based modeling. How these newer experimental methods and concepts of constraint-based modeling approaches can be applied to metabolic studies is illustrated by examples of studies in determining metabolic responses of cells to pharmacological agents and nutrient environment changes.
The Pancreas: Biology, Pathobiology and Diseases
The classic textbook, “The Pancreas: Biology, Pathobiology and Diseases,” published by Raven Press in 1993 is now available in its entirety online on the Pancreas Journal’s website. This book summarizes the state of the art of our disciplines in biology, pathobiology and diseases of pancreas up to 1990. The articles that appear in the journal Pancreas, which started publishing in 1986, has provided most of the progress and advances in the field since then. The book is an excellent companion and provides continuity in the advances of pancreatology. We are grateful to our publisher, Lippincott Williams & Wilkins, for providing all the chapters of the book in open access and for providing additional references and historical perspective of our field.
The book can be found free online here.