Published by the MIT News Office at the Massachusetts Institute of Technology, Cambridge, Mass.
Published by the MIT News Office at the Massachusetts Institute of
Technology, Cambridge, Mass.
BIOLOGY FOCUS Technology Day 1991: A Deep Probe Into Life by Eugene F. Mallove News Office An event-filled Technology Day 1991 explored "The Impact of Molecular Biology on Your Health," or more colloquially, as its colorful "Pillsbury Dough-Man" poster announced, "Sex, Drugs, Genes, and Obesity." Last Friday's convocation examined research in the health sciences at MIT and its impact on our lives. In opening remarks, President Charles Vest praised biological research as "one of the jewels in the crown of MIT" and noted the recent faculty action that makes MIT the first university in the country to require students to take a biological science subject, beginning with the class entering in 1993. Professor of Biology Harvey F. Lodish moderated the proceedings in Kresge Auditorium and provided an overview of life sciences research here, which he said is supported by about 60 faculty members, 270 upperclassmen enrolled in biology, 170 graduate students and 200 postdoctoral fellows. Professor Lodish noted that MIT's current "preeminent position" is a far cry from the late 1960s, when "people were surprised to hear that MIT had a biology department." Lodish noted the high quality of the biology faculty, of which two present and two former members are Nobel laureates. Unusual for almost any department, half of the biology faculty are members of the National Academy of Sciences. The biology faculty has an impact outside MIT too, Lodish said. Eleven members have been instrumental in founding biotechnology companies, and the department is increasingly "a home for international scientists from throughout the world." Associate Professor Eric Lander's revealing opening talk, "Human Genetic Diseases and the Human Genome Project," set the context for the morning's look at the biological revolution. "Human genetics has been transformed completely since 1980 by an idea born at MIT," he said, by former MIT Professor David Botstein. Botstein's seminal idea led to a completely new way to unravel genetic mysteries--from inherited physical traits to genetic diseases--that has culminated in the Human Genome Project now underway. Up to 1980, human genetics relied on "being lucky" and in being very "smart" in genetic detective work, Lander said. He said that the new approach to finding genetic origins of human conditions now relies on finding where in our DNA a condition may originate, instead of guessing merely what may be genetically derived. There is now a rapidly expanding knowledge of the genetic origin of human traits--some 4,000 traits have already been cataloged. On average, Lander noted, our individual DNA is 99.9 percent identical to that of fellow human beings. That all-important one-tenth of a percent variation provides the vast differences among people, from height differences and serious inherited diseases to seemingly trivial differences such as how we clasp our arms. Sometimes a very small alteration in human DNA, such as the deletion of a mere three chemical "letters" of the three billion in a person's DNA genetic complement, can lead to catastrophic results--the disease cystic fibrosis, for example. In that ailment, the genetic miscoding causes a particular "transport" protein in cell walls to be improperly shaped because it has lost a particular amino acid. Among fundamental phases of the Human Genome Project already underway, said Professor Lander: are creating a basic genetic map--a significant fraction of which has already been done, the physical mapping akin to "the infrastructure of our highway system"--to be completed in about five years, and creating the ultimate three-billion-letter detailed sequence map, which may be done within 15 years. Computer technology may accelerate the process. "Molecular biology and computer science are the only two fields that are proceeding in log- linear fashion," Professor Lander remarked, in noting the dramatic annual improvement in speed of techniques to sequence DNA. Some diseases, such as atherosclerosis, diabetes, obesity, and autoimmune disorders, have very complex genetic inheritance mechanisms that require the function or dysfunction of many genes. "By peeling away the onion" of this complexity with the techniques of molecular biology, scientists can reveal the genetic causes of these diseases, Dr. Lander said. Some diseases, such as the very rare Werner's syndrome--extremely premature aging--may not seem to justify the vast resources needed to conquer them, he said, given the limited number of victims. But scientists might gain insight into fundamental biological processes, such as aging, by studying such anomalies. Professor Lander warned against common misconceptions about genetic inheritance. For example, if something is genetically transmitted, it is not necessarily predestined and unchangeable. "Nature versus nurture" is not always clear-cut. "Increasingly we see that it is not one or the other, but a combination of the two," Professor Lander said. Genes do not always directly control human behavior, nor do genes limit human potential. Professor Robert Rosenberg '69 then launched a broad overview of the causes of heart attacks and current attempts to deal with them. "We've come a long way in the last 10 years," he said. "We've begun to uncover some of the causes of heart attacks and we've begun to develop therapies that are really quite effective. . . MIT has a real role in developing progress in this area." NIH has designated MIT one of the three National Programs of Excellence in the use of molecular biology to unravel the problems of the cardiovascular system. "In my view this program, coupled with the Human Genome Project, has a real chance of picking out what are the alterations in genes which cause the great bulk of these diseases," Professor Rosenberg said. "I think that with this knowledge it is quite clear that we'll be able to develop more innovative therapies for preventing heart attacks." Professor Emeritus Herman Eisen, who serves on an advisory board of the National Academy of Sciences to oversee the entire AIDS program of NIH, spoke on "Immunity and AIDS." He explained how the HIV virus has evolved a very subtle strategy for changing the protein composition on its surface so that it evades the antibodies that the body's own immune system forms against it. In effect, the virus maintains itself in its host by a form of Darwinian microevolution taking place over a period of weeks or months. "The virus stays ahead of the immune system," he said. "The outlook for the short term is not one that can generate tremendous optimism. I think that the development of AZT has already had an impact on lengthening the incubation period of the disease so that it has some effect," Professor Eisen said. "That says that there are possibilities for other drugs being developed. . . I think that there is reason to believe that eventually we will have either a vaccine or drugs or both. But by 'eventually,' I think we have to accept the fact that we are talking about several years--five, maybe ten, something of that sort, as a sheer guess." Professor Lodish introduced Professor Robert Weinberg '64 as the "founder of the field of human carcinogenesis--the development of oncogenes or genetic changes that cause human cancer." Dr. Weinberg, who has two MIT degrees, called himself a "Tech man born and bred; I'm a product of incest and inbreeding, still in the department that trained me, and I'm proud of it." Echoing the day's theme, he joked, "I'm of male sex, I don't take drugs, I have genes, and I'm moderately obese, so here I am. "The great majority of cancer does not come from inborn predisposition, but rather comes as a consequence of accidents that occur during our lifetimes, accidents to our genes. Not that we inherit damaged genes, but that we damage them as a consequence of our lifestyles, of our diet, and so forth." Cigarette smoking causes cancer, he cited as a major example. "At least for the present, the rates of most commonly occurring cancers are not increasing--the popular press not withstanding--and so far at least, the vast bulk of human cancer is not being influenced to any great extent by environmental pollution, which is once again against the grain of popular perception, or at least what one would deduce from reading the everyday newspaper," he said. "All the cells in a tumor are all the descendants of a single ancestral cell that began to go awry. . . Now we begin to understand this evolution in terms of a model which is very similar to Darwinian evolution. . . We can now begin to picture--to conceptualize--the evolution of normal cells into tumor cells in terms of a succession of defined and definable genetic alterations, each one hitting one or another target genes. These altered genes conspiring together to orchestrate the final music or cacaphony of cancer." Technology Day 1991 continued in the afternoon with small panels, lectures, and open houses to allow attendees to participate in discussions of research in molecular biology and its social and ethical implications.