Systems and Networks

Given the growing interest in the area of drug development through the use of systems biology – both at a molecular level and within a whole organism – it is clear that the value of interactions can no longer be defined in terms of a single exchange of a signal from source to recipient. In a similar way, regional and national networks are not focused on single exchanges of information within the region, but look to amplify these signals through transfer and dialogue across their numerous interfaces. This article explores the ways in which networks – whether their purpose is the exchange of cellular signals or of knowledge – act to amplify the messages they create.

UNDERSTANDING NETWORKS

The emerging field of systems biology includes a strong focus on the network perspective within biological systems. This is of particular significance within the realm of drug discovery, which used to be built on, at most, tissue-level screens but, more often, relied on simple cell-based pathway screens. The identification of targets involved blocking the interactions of individual molecules at a single junction of the cell processes, often in isolation from the background melee of cellular signals they were operating within.

In the advent of understanding the role that whole systems play, it seems that methodologies that filter information for significance, such as biological context and relevance, are now being regarded as crucial to the successful understanding of different levels of organisation in systems biology research. Today, biologists are looking at the organisation of interacting proteins and protein complexes into networks, and these networks are being examined to elucidate underlying principles and activities that will enable us to understand how to influence a disease process. In fact, more and more information is being sought on how functional relationships exist within biological networks and how signals may be amplified within them. Understanding how such networks operate is key to being able to manipulate changes within the biological systems. So, progress is being made in understanding the effectiveness of networks in their ability to control messages through mechanisms such as signal amplification and noise filtering.