Beatrice Mintz

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Beatrice Mintz

Beatrice Mintz is an embryologist who has been responsible for a number of advances in the understanding of cancer while working in the laboratories at the Institute for Cancer Research in Philadelphia. She has published over 150 papers on a wide range of experimental approaches in the field of developmental biology, helping to establish the role of genes in differentiation and disease.

Beatrice Mintz developed new strains of mice with a genetic predisposition to melanoma, thus offering the first experimental opportunity to analyze the progression of this disease, which is the fastest growing cancer among young people in the United States. In one experiment, she successfully accomplished the hereditary transmission of human skin melanoma cells to transgenic mice. In another experimental approach, she injected the human betaglobulin gene into fertilized mouse eggs, and this gene was then transmitted by that generation of mice to their offspring in a Mendelian ratio.

Mintz was born in New York City on January 24, 1921 to Samuel and Janie Stein Mintz. She attended Hunter College and received her A.B. in 1941; she graduated magna cum laude, and a member of Phi Beta Kappa. In the following year she did graduate work at New York University and then transferred to the University of Iowa where she received an M.S. in 1944 and a Ph.D in 1946. She served as a professor of biological science at the University of Chicago from 1946 to 1960. Since then, she has devoted her efforts to investigations at the Institute for Cancer Research.

Mintz has made her most important contributions to cancer research with her experiments on the embryos of mice. The techniques she has developed to manipulate the embryos have made it possible to establish the genetic transmission of certain kinds of cancer, such as melanoma, a dangerous skin cancer. She has utilized a number of delicate laboratory techniques, such as injecting a few individual cells into the blastocysts—or early embryos—of mice in vitro, and then surgically transferring these early embryos into surrogate mothers, who then gave birth to mice whose traits were traceable. She has managed to inject the liver cells of fetal mice into the placental circulation of other mouse fetuses, thus ultimately developing a new pool of donor-strain stem cells for red and white blood cells. She has also developed techniques for in-vitro freezing of cells in liquid nitrogen before culturing them. She concluded from her investigations that human DNA could be assimilated into the germ line of mice for in-vivo research into the regulation of genetic diseases.

In the early l960s, Mintz pioneered techniques for producing mammalian chimeras using mouse embryos. Chimera is a word from Greek mythology which describes an animal with a goat's head, a lion's body, and a serpent's tail. The mammalian chimeras Mintz produced were also composites, though they were merely the composites of genetic strains from different mice. She invented methods to develop them from more than one fertilized egg; she would take as many as fifteen embryos of different strains of mice and push them together until the cells aggregated into a single large blastocyst, which was then implanted into a foster mother. The offspring of these mice often reveal differing patterns of pigmentation and skin graft reactions.

In another experiment, Mintz succeeded in producing individuals with four, rather than two, parents. Early embryos consisting of only a few cells were removed from pregnant mice and placed in close contact with similar cells of genetically unrelated embryos to form a composite, unified embryo; this was then surgically implanted in the uterus of a mouse, which gave birth to a mouse that was a cellular mosaic—its tissues comprising genetically different kinds of cells. This technique is particularly valuable for tracing the tissue site of specific genetic diseases. In addition, Mintz established that when mouse embryo cells from a malignant tumor known as tetracarcinoma were combined with normal mouse embryo cells, the cancer cells developed into normal cells.

Mintz was awarded a Fulbright research fellowship at the universities of Paris and Strasbourg in 1951, and she has continued to receive many honors and awards, including the Papanicolaou Award for Scientific Achievement in 1979, and an Outstanding Woman in Science citation from the New York Academy of Sciences in 1993. She was also the recipient of two other honors, the Genetics Society of America Medal in 1981, and the Ernst Jung Gold Medal for Medicine in 1990. Five colleges, including her alma mater, have awarded her honorary doctorate degrees. She has been invited to deliver over twenty-five special lectureships, including the Ninetieth Anniversary Lecture at the Woods Hole Marine Biological Laboratory in 1978, and the first Frontiers in Biomedical Sciences Lecture at the New York Academy of Sciences in 1980. She is a member of the National Academy of Sciences, a senior member of the Institute for Cancer Research, Fox Chase Cancer Center, Philadelphia, and serves on the editorial boards of various scientific journals. In 1996, she and Ralph Brinster, Professor of Reproductive Biology at the University of Pennsylvania School of Veterinary Medicine, won the first March of Dimes Prize in Developmental Biology. Working independently, Mintz and Brinster were honored for contributions in developing transgenic mice, now a staple in labs worldwide. She continues to strive to carry out creative and original scientific work, designing experiments that have the potential for raising new and unforseen questions.