Marc Vidal, PhD, studies a computer-generated image of genes belonging to the microscopic worm C. elegans
Key players, bit actors
Marc Vidal, PhD,'s objective at Dana-Farber resembles Lynda Chin's: distinguishing genes that are the "mainsprings" of cancer from those that are minor cogs. His method of doing this, though, is quite different.
Vidal compares his approach to commercial air traffic. "Every flight is just a small part of an intricate network," he says. "If there's a snowstorm that closes down a single hub airport, it has ripple effects across the entire system." In the past, scientists have viewed cancer-causing genes as single entities. "Each one is like an airline flight — beautiful and complex in its own right — but it has to work properly for the system to function."
From that perspective, knowing all the genes in the genome is a crucial start, but only a start, to the mammoth and almost dizzyingly complex subject of the relationships between genes. The task of understanding those links — a challenge further complicated by the fact that genes interact with one another differently under varied conditions — is the focus of the emerging field of Systems Biology. At Dana-Farber, the discipline has gained a foothold with the opening of a dedicated suite of laboratories under the direction of Vidal, Todd Golub, MD, and William Hahn, MD, PhD.
"Systems Biology is concerned with how the functions of molecules fit into each other," Vidal explains. "From there, the aim is to extract the rules of how they work — not one molecule to another, but as a system."
Of particular interest are genes that have a high number of connections with other genes noted. Physicist Albert-László Barabási of Notre Dame has found that in most networks — be it the World Wide Web or neurons in the brain — the vast majority of points are only scantily linked to others, while a very few are super-highly connected. Vidal and his colleagues will be tracking the skein of interactions within the human genome to determine how it is altered by cancer.
"It seems that genes with many interconnections are more likely to be essential for life," Vidal says. "We're exploring whether cancer-causing mutations tend to be in these 'hub' genes, and whether cancer somehow alters the balance of interactions throughout the genome."
