Systems Biology and Complex Disease

Abstract

After "human genome project" has been accomplished, the life science comes to a new era, the post-genome era. In the post-genome era, the "big sciences" such as genomics, proteomics and metabolomics (so-called "omics") gradually become a new popular research methodology to provide global pictures of cells or organisms, although the classical experimental biology (small sciences) such as molecular biology or cell biology is still the mainstream in life sciences. The concept and strategy of omics is completely different from the classical experimental biology. The omics is called a "discovery science", of which the goal is to identify all the genes or proteins in the organisms, whereas the classical experimental biology such as molecular biology is called a "hypothesis-driven science", since the researches of these disciplines are initiated based on the scientific hypothesis and focus on studying the structure and functions of individual gene or protein. Systems biology is a newly born discipline in the post-genome era, which integrates the research strategy of classical experimental biology such as molecular biology with the new research strategy of "omics". Systems biology is also a new interdisciplinary frontier based mainly on the integration of the "wet" experiments such as molecular biology or "omics" with the "dry" experiments such as bioinformatics and computational biology. Technology of systems biology includes the "omics" platforms such as proteomics-platform and the theoretical platforms for computing and modeling. From these properties, Systems biology is defined as an integrating methodology for analyzing the components and dynamical behavior of biological systems as a whole. More importantly, these properties have made systems biology as a powerful analytical tool to reveal the complex diseases such as cancer and diabetes. Although the complex diseases have been extensively studied for a long term, it is far beyond understanding the mechanisms of the disease-process and curing these diseases. The difficulties for dealing with the complex diseases arise from the aspects of the complex diseases: 1) the causes of the initiation and development of the complex diseases involve multiple genetic factors, environment factors and the interaction of these two kinds of factors. 2) the different kinds of cells or tissues involve in the diseases. For example, the brain, pancreas, liver, skeletal muscle and adipose tissue mainly involve in the type 2 diabetes. 3) the molecular defects for the complex disease disrupt the normal behaviors of the complex molecular networks of genes and proteins. The classical bio-medicine based on molecular biology, cell biology, genetics and other experimental biology has made significant progress for against disease in general. However, the researchers on the bio-medicine area still face the great challenge for against the complex diseases such as cancer and diabetes since the methodology of the classical experimental biology is based on studying individual gene and protein and treat the organisms as a simple and linear system, which is not good enough to solve such problems of the complex diseases. Therefore, it is clear that the methodology and techniques of system biology must be applied for analyzing the molecular mechanisms of the complex diseases, and provide new solutions for preventing and curing the diseases.