RandyW Posted December 6, 2006 Share Posted December 6, 2006 The birth of a tumor Researchers explore connection between embryo's growth and cancer's spread By Liz Kowalczyk, Globe Staff | December 4, 2006 When cancer strikes, tumor cells multiply furiously, migrating to other organs. When embryos develop, cells multiply furiously, migrating to begin creating organs. Article Tools Printer friendly Single page E-mail to a friend Health / Science RSS feed Available RSS feeds Most e-mailed Reprints & Licensing Share on Facebook Save this article powered by Del.icio.us More: Globe Health / Science stories | Health & Fitness section | Science section | Globe front page | Boston.com Sign up for: Globe Headlines e-mail | Breaking News Alerts It is a similarity that has long tantalized scientists. Now researchers are beginning to mine evidence that there's a real connection between cancer and early human development. Cancer, it seems, somehow reactivates and then hijacks dormant programs in cells that were active at the very beginning of life. "Cancer doesn't have to cobble together his behavior," said Robert Weinberg, a researcher at the Whitehead Institute for Biomedical Research in Cambridge and a professor at the Massachusetts Institute of Technology. "It just puts in the CD and starts playing the music." The spread of cancer from the initial tumor causes 90 percent of cancer deaths, so researchers are increasingly trying to understand and detect early signs of this spread, called metastasis, and perhaps even halt it. INTERACTIVE GRAPHIC: Zeroing in on how cancer spreads Unlike cancer, embryos eventually switch off the rapid proliferation of cells and direct them to stop relocating. Researchers hope they someday will be able to harness these controls, some of which have already been identified, and develop drugs that mimic them to treat cancer. The link between embryonic development and cancer is seen as such a promising area of inquiry that Weinberg will use some of the $20 million gift MIT received from the Ludwig Institute for Cancer Research last month to support the work. Scientists have suspected for more than a century that cancer growth and embryonic development share certain characteristics. Primitive microscopes confirmed this idea on the crudest level, revealing that both involve unchecked cell replication. During the last five to 10 years, scientists have been able to study this connection in a far more detailed way using new technology that can tell when specific genes are turned on or off -- called gene expression -- and huge databases that map the genetic makeup of tumors, as well as the genes involved in embryonic development. By looking at which genes are turned on in embryos to allow cell movement, for example, researchers can narrow down their search in cancer and see if those same genes are responsible for the spread of cancer cells. "It's allowed us to bring old ideas into the modern world," said Dr. Isaac Kohane, a researcher at Children's Hospital . As a result, research into the connection between cancer and early development of the embryo has accelerated and is now "a very hot and rapidly growing field," said Weinberg, who last year published research on the link between the growth of mice embryos and melanoma, the deadliest form of skin cancer. Melanoma, cases of which are increasing, is a particularly aggressive type of cancer that spreads through the body faster and with greater voracity than most tumors. More than 40 percent of patients whose cancer has migrated into the lymph nodes, are dead within a decade.Continued... Weinberg's team found that a gene that enables certain early embryonic cells to travel also is highly active in melanoma. In a tumor, the gene, named Slug, allows cells to detach from one another and travel throughout the body. Mice injected with melanoma cells containing this gene immediately developed invasive tumors that spread throughout their body. But when researchers shut off this gene in melanoma cells the cancer was unable to metastasize when injected into mice. Melanoma cells are derived from melanocytes, the pigment-producing cells that protect the skin from sun damage. It's possible, Weinberg said, that melanoma spreads faster than most other cancers because, in an embryo, melanocytes need to spread across the embryo to pigment the skin. The precursors to breast cells, however, do not migrate much during embryonic development, so the programs they use to spread are likely to be far more complicated and may not be as tied to embryonic development, he said. Scientists also have been studying the link between early development and lung cancer and brain tumors. At Children's Hospital Boston, scientists this summer published evidence of an embryo-tumor link in lung cancer. Researcher Hongye Liu, who works with Kohane, identified 596 genes whose expression was either turned up or turned down both in lung cancer and lung development. She and her colleagues found that the tumors with a pattern of gene expression most similar to early lung development were the most lethal. Kohane said he hopes the work will help doctors more accurately diagnose the stage of a patient's lung cancer, and therefore improve treatment. Kohane and Weinberg said it's too early to predict whether scientists will be able to develop cancer drugs based on this research. Oncology companies, however, are already testing certain compounds based on these ideas in animals and soon may test one drug for brain cancer on a small group of patients, said Dr. Rosalind Segal, a neurooncologist at Dana-Farber Cancer Institute. Segal studies molecular pathways that control normal brain growth in the embryo, which of these pathways are active in brain cancer, and the mutations in cancer cells that keep these pathways stuck in the "on" position. Some clinicians who treat cancer patients are cautious about the potential applications of this research. For one, developing drugs to mimic controls on embryonic cell mobility would not help patients who are diagnosed after their cancer already has spread, as is the case for many people. Cancer cells also have so many mutations that the ways a normal embryo controls growth and movement may not be applicable. "The breast cancer genome looks like it's been blown apart by a bomb; it's full of rearrangements and full of mutations," said Dr. Dirk Iglehart, a surgeon and researcher at Dana-Farber. "It's entirely scrambled at the DNA level. In that way, embryos are not at all like human cancer." © Copyright 2006 Globe Newspaper Company. 1 2 Next Home > News > Boston Globe > Health / Science The birth of a tumor Researchers explore connection between embryo's growth and cancer's spread By Liz Kowalczyk, Globe Staff | December 4, 2006 When cancer strikes, tumor cells multiply furiously, migrating to other organs. When embryos develop, cells multiply furiously, migrating to begin creating organs. It is a similarity that has long tantalized scientists. Now researchers are beginning to mine evidence that there's a real connection between cancer and early human development. Cancer, it seems, somehow reactivates and then hijacks dormant programs in cells that were active at the very beginning of life. "Cancer doesn't have to cobble together his behavior," said Robert Weinberg, a researcher at the Whitehead Institute for Biomedical Research in Cambridge and a professor at the Massachusetts Institute of Technology. "It just puts in the CD and starts playing the music." The spread of cancer from the initial tumor causes 90 percent of cancer deaths, so researchers are increasingly trying to understand and detect early signs of this spread, called metastasis, and perhaps even halt it. Unlike cancer, embryos eventually switch off the rapid proliferation of cells and direct them to stop relocating. Researchers hope they someday will be able to harness these controls, some of which have already been identified, and develop drugs that mimic them to treat cancer. The link between embryonic development and cancer is seen as such a promising area of inquiry that Weinberg will use some of the $20 million gift MIT received from the Ludwig Institute for Cancer Research last month to support the work. Scientists have suspected for more than a century that cancer growth and embryonic development share certain characteristics. Primitive microscopes confirmed this idea on the crudest level, revealing that both involve unchecked cell replication. During the last five to 10 years, scientists have been able to study this connection in a far more detailed way using new technology that can tell when specific genes are turned on or off -- called gene expression -- and huge databases that map the genetic makeup of tumors, as well as the genes involved in embryonic development. By looking at which genes are turned on in embryos to allow cell movement, for example, researchers can narrow down their search in cancer and see if those same genes are responsible for the spread of cancer cells. "It's allowed us to bring old ideas into the modern world," said Dr. Isaac Kohane, a researcher at Children's Hospital . As a result, research into the connection between cancer and early development of the embryo has accelerated and is now "a very hot and rapidly growing field," said Weinberg, who last year published research on the link between the growth of mice embryos and melanoma, the deadliest form of skin cancer. Melanoma, cases of which are increasing, is a particularly aggressive type of cancer that spreads through the body faster and with greater voracity than most tumors. More than 40 percent of patients whose cancer has migrated into the lymph nodes, are dead within a decade. Page Quote Link to comment Share on other sites More sharing options...
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