The Center for Alternatives to Animal Testing is an academic center affiliated with the Division of Toxicological Sciences in the Department of Environmental Health Sciences of the Johns Hopkins University Bloomberg School of Public Health.

 

Johns Hopkins School of Public Health

Abstract for TestSmart--Pharmaceuticals: An Efficient and Humane Approach to Predictors of Potential Toxic Effects of Drugs

Beyond The Genome To Tissue Proteomics

Emmanuel F. Petricoin, III
Center for Biological Evaluation and Research, US Food and Drug Administration

The target for most therapeutics, licensed and in the drug development pipeline, is the protein. Therefore, it is imperative that proteomic analysis is employed to study, discover and effectively treat human disease. Proteomics represents the next frontier beyond the genome as now many biotechnology and pharmaceutical companies are turning their focus to this field. However, unlike the genome, which is relatively stable form person to person and cell to cell, each cell type has its own unique proteome and the elasticity of the proteins expressed are predicated by the environment that the cells are living in. Therefore, the absolute impact of these findings will be predicated on the assignment of biological relevancy to this wealth of information. To that end, the FDA/CBER-NCI Tissue Proteomics Initiative was started over three years ago to employ the use of laser capture microdissection, for the first time ever, to the proteomic analysis of microdissected subpopulations of human solid tumors (prostate, lung, breast, ovary, and esophageal) as a model for the study of disease progression. The proteomic program is organized by:

  1. A Low-throughput protein discovery module using two-dimensional polyacrylamide gel electrophoresis (2D-PAGE) and tandem electrospray MS-MS. To date over 150 proteins have been identified.
  2. A medium throughput protein array module for the invention and application of array-based technologies for target validation and multiplexed signal pathway profiling for toxicity detection, drug efficacy assessment during clinical trials and new signaling target discovery. We know from recent work in the burgeoning field of cytokine, growth factor, and apoptosis signal transduction, that most induced or cell-specific gene expressions are regulated by complex protein-protein interacting pathways which are linked from the cell surface to the nucleus through protein modifications such as phosphorylation. These pathways are almost always aberrantly modified in most disease states and reflected in the subtle protein changes in the cell. These changes in protein expression are ultimately translated into changes in cell growth, differentiation and/or apoptosis.
  3. A high-throughput rapid proteomic profiling module that employs surface-enhanced laser desorption and ionization (SELDI) coupled with artificial intelligence to identify proteins patterns aberrantly produced in a disease-specific, efficacy specific and toxicity-specific manner. These protein patterns are being used to identify early disease detection, efficacy assessment and toxicity prediction in ongoing clinical trials and pre-clinical animal studies.