Frontiers

This airy quality of mind enables scientists to tour tumor interiors, visit the depths of cancer cells, scout molecular pathways … and make breakthroughs.

By Darrell E. Ward
Photograph by Roman Sapecki

Carlo Croce, MD, The John W. Wolfe Chair in Human Cancer Genetics, professor of Molecular Virology, Immunology and Medical Genetics, director of OSU’s Human Cancer Genetics program

“Imagination,” he declared, “is more important than knowledge.”

It’s a stunning assertion, but highly creative scientists at Ohio State University’s Comprehensive Cancer Center agree without hesitation.

“It is true,” says Carlo M. Croce, MD, chair of Molecular Virology, Immunology and Medical Genetics, an OSUCCC researcher and member of the National Academy of Sciences. “If you have a very good imagination, then you will do original science. Otherwise, you may do work that is good, but it won’t have the sparkle of a breakthrough. For breakthroughs, the most important attribute is imagination.”

Croce is known for breakthroughs. He received the 2008 Léopold Griffuel Prize from the French Association for Cancer Research, for example, for early work showing that chromosome translocations initiate malignant transformation, and for recent work linking microRNA genes directly to cancer pathogenesis.

In the early 1980s, he said, “We thought of using chromosomal translocations to identify genes responsible for human cancer. At that time, the significance of chromosomal translocations that had been observed in cancer was not known. Most people thought they were the result of malignant transformation. We suspected that they were the cause.

“So we looked at diseases having a very high frequency of a specific translocation, and we found, in fact, that chromosomal translocations involved in cancer activate specific oncogenes.

“That was very revealing, and it was the fruit of imagination more than of knowledge.”

Images of DNA strands, hairpins of RNA, and molecular pathways moved through his head as he led research that discovered the BCL2 gene, identified it as the cause of follicular lymphoma and helped establish the new field of apoptosis research.

In 2002, he led breakthrough research demonstrating micro-RNA’s role in cancer development, followed by other work describing a new type of RNA, ultraconserved noncoding RNA.

Knowledge, of course, is essential for medical research, Croce says, “but you must use it as a springboard for your imagination.” Imagination must be restrained by facts, by what is feasible given the technology that is available. “To go after something that is not feasible is just stupid,” Croce says.

There are hazards to imaginative research. It means taking risks. But Croce encourages risk-taking. “Formulate a well-thought out hypothesis, then design experiments to demonstrate that it is really right,” he says.

And funding may be difficult to obtain. “The present granting system does not support imagination, and high-risk, or even some-risk, types of approaches may not get funded,” Croce says. “But this is nothing new, and you learn to cope with it.”

Anticipating the Outcome

THE RESEARCHER Albert de la Chapelle, MD, PhD, Co-leader of the Molecular Biology and Cancer Genetics Program

“To understand something biological, you first must ask yourself what could be responsible for this new observation,” he says, “then you list all the theoretical possibilities that might explain it, and then you use imagination to choose the most likely one to test first.”

Whenever de la Chapelle gathers the members of his laboratory to plan an experiment, even as their meeting is breaking up, he is imagining its likely outcome.

“Some people plunge ahead, do the experiment, see what happens, then plan the next experiment,” he says. “I want to imagine what is going to happen before it happens. Even guessing the outcome is worthwhile because it helps me prepare for the next step.”

In 2008, de la Chapelle led a study that discovered a possible new cause of colon cancer. Nearly a third of people with colon cancer have a history of the disease in the family, but less than 5 percent of cases have been linked to an inherited mutation.

“We’ve long known that there must be other predisposing genes,” de la Chapelle says, “and people around the world have looked for them, but nobody has found them. We found what may be a major one, the transforming growth factor beta receptor 1 gene, or TGFBR1.”

Abundant circumstantial evidence implicated TGFBR1 in colon cancer. It is part of a pathway heavily involved in colon cancer, and a variety of linkage and association studies had traced an unidentified colon-cancer gene to the same region of chromosome 9 where TGFRB1 is located.

“But this region was big enough to contain about 200 genes,” de la Chapelle says. Numerous laboratories had sequenced the gene looking for mutations, but none were found.

Eager to solve the problem, de la Chapelle brainstormed daily about the problem with others in his research group. “We fantasized that finding an obvious mutation was highly unlikely. Instead, we chose to look for a subtle difference in expression between the gene’s two alleles, and we went straight for it.”

In fact, they found that the expression of one allele was one-third or more lower than the other in 29 of the 138 colon-cancer cases examined (21 percent) and in 3 of 105 non-cancer controls (3 percent). “This strongly suggests that the gene plays an important role in the disease,” de la Chapelle says.

Stress and immunity

THE RESEARCHERS Janice Kiecolt-Glaser, PhD, Professor of Social and Behavioral Sciences and of Psychiatry–Health Psychology Ronald Glaser, PhD, Director, Institute for Behavioral Medicine Research

Kiecolt-Glaser, Glaser and collaborators William B. Malarkey, MD, an endocrinologist and director of Ohio State’s Clinical Research Center, and John F. Sheridan, PhD, associate dean for Research, College of Dentistry, an immunologist with a strong background in animal models and stress, have made unusual and important discoveries that have opened entirely new areas of study.

The researchers’ early studies showed that caregivers who were stressed or depressed had poorer immune responses that could leave them more susceptible to disease.

But did these changes have real consequences? “If your T cells don’t proliferate, that’s bad news, but what does it mean for a person’s health?” Kiecolt-Glaser asks. It was hard to say because normal values for such markers didn’t exist.

Glaser, director of Ohio State’s Institute for Behavioral Medicine Research, had an imaginative solution: “Let’s use a vaccine.”

A series of studies followed in which the researchers marked immune health in study participants according to their ability to produce antibodies to a standardized dose of influenza or HBV vaccine.

In one study, the investigators compared people caring for a spouse with Alzheimer’s—the stressed group—with a matched group of non-caregivers and measured the ability of each to produce antibodies to influenza vaccine. They found that the caregivers had much lower T-cell responses and antibody titers after vaccination, and that their peripheral blood leukocytes produced lower levels of interleukin 2 in response to antigen stimulation.

“The vaccine data suggested that the caregivers were much more vulnerable than their controls to influenza and, possibly, to other infectious agents,” Kiecolt-Glaser says. “There is now rich literature on vaccine responses and stress showing that stress or depression alter responses to a whole variety of vaccines.”

Kiecolt-Glaser, Glaser and their colleagues followed their vaccine research with a series of studies investigating how stress, including martial discord, affects wound healing, another measurable immune response. For some of these studies, the researchers inflicted small blister wounds on the forearm and monitored healing and local production of proinflammatory cytokines.

“We showed that stress has a significant effect on wound healing,” Kiecolt-Glaser says. “Much bigger than we had anticipated.”

Imagination for Understanding

THE RESEARCHER Clay Marsh, MD, Director, Center for Critical Care, and an OSUCCC researcher

“In the clinic, if someone has chest pain, you take the person’s history and based on the history and exam, you order certain tests to determine the cause—which could be a heart attack, blood clot to the lung, pneumonia or trauma. You run through the possibilities, formulating ideas about possible causes and visualizing what might be going on physiologically,” Marsh says.

“It’s the same in the research laboratory,” he says. “You consider all possible causes when trying to understand the outcome of an experiment. By talking with others in your laboratory and to your collaborators, you can end up with a long list of possibilities. Then you use intuition and imagination to narrow them down.

“To be creative in research requires that you use your imagination,” he says.

Marsh’s studies include investigating how tumors influence the behavior of macrophages, and the role of these inflammatory cells in facilitating new blood-vessel growth to tumors.

“We’re trying to learn how to manipulate, or re-educate, macrophages drawn into the tumor microenvironment to behave in the opposite manner, so that they inhibit tumor growth.”

Marsh uses his imagination to travel a tumor’s landscape. “I visualize the tumor’s connective tissue and the factors in the tumor matrix that guide the macrophages’ movement. I visualize how the macrophages might interact with the tumor cells and with the tumor’s blood vessels, and how tumor cells might penetrate those blood vessels and spread systemically.

“We try to understand the molecular components in each of these areas, the genes and the proteins that control the cells, working backwards and forwards to understand an experiment’s outcome.

“You’re constantly imagining what’s happening and trying to figure out what makes sense, while being careful not to convince yourself that something is true before you prove it. As experimental data is generated, you change your image of what is happening. All the while, you imagine how the elements might play together, interact.

“However, it is the end result or phenotype of the outcome that helps us understand important events in the tumor environment. Maybe a type of tumor grows and spreads early in one group of people, but the same tumor doesn’t spread at all in another group. You would investigate what’s different about the people in each group. Based on the results, you imagine how these differences might explain the dissimilar outcomes.”

It’s not unusual to approach research questions with preconceived ideas, Marsh says. “But doing biomedical research is like riding a wave. If you are in the ocean, swimming against the current is difficult, similar to forcing observed data to fit a preconceived hypothesis. If, on the other hand, you keep your mind and imagination open to what you find and to where your data lead, you can make powerful discoveries.”