Individualized Medicine: Genetically Fine-Tuning Prevention, Diagnosis, and Treatment of Disease
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Developed by the Federation of American Societies for Experimental Biology (FASEB) to educate the general public about the benefits of fundamental biomedical research. INSIDEthis issue Individualized Medicine: Genetically Fine-Tuning Prevention, Diagnosis, and Treatment of Disease In search of the gene 1 On the cutting edge 4 Spelling out the human genome 7 A decade of progress 8 Next generation sequencing 10 The future of individualized medicine 11 Acknowledgments Individualized Medicine: Genetically Fine-Tuning Prevention, Diagnosis, and Treatment of Disease Author, Margie Patlak Scientific Advisor, Howard P. Levy, MD, PhD, Johns Hopkins University Scientific Reviewer, Rex L. Chisholm, PhD, Northwestern University Feinberg School of Medicine BREAKTHROUGHS IN BIOSCIENCE COMMITTEE Paula H. Stern, PhD, Chair, Northwestern University Feinberg School of Medicine Aditi Bhargava, PhD, University of California San Francisco David L. Brautigan, PhD, University of Virginia School of Medicine Blanche Capel, PhD, Duke University Medical Center Rao L. Divi, PhD, National Cancer Institute, National Institutes of Health Marnie Halpern, PhD, Carnegie Institution for Science COVER: Individualized medicine, also known as Tony E. Hugli, PhD, Torrey Pines Institute for Molecular Studies personalized medicine or genomic medicine, is a medical paradigm offering customizable medicine based on one’s Edward R. B. McCabe, MD, PhD, March of Dimes Foundation genes that can be used to prevent, diagnose, and treat disease. Innovations in individualized medicine come from Loraine Oman-Ganes, MD, FRCP(C), CCMG, FACMG, Sun Life technological advances that make it both feasible and affordable to decipher a person’s complete genetic make-up. Financial By exploring answers to basic questions about microbes, cancer, the immune system, and other biological processes, Sharma S. Prabhakar, MD, MBA, FACP, Texas Tech University scientists have fostered the current genetic revolution Health Sciences Center in medicine that is helping physicians find the right treatment for the right patient at the right dose. Image R. Brooks Robey, MD, FASN, FAHA, White River Junction VA credits: Lonely/shutterstock (DNA), r.classen/shutterstock Medical Center and Geisel School of Medicine at Dartmouth (medication); Designed by Corporate Press. Scott I. Simon, PhD, University of California Davis BREAKTHROUGHS IN BIOSCIENCE PRODUCTION STAFF Managing Editor, Anne M. Deschamps, PhD, Senior Science Policy Analyst, FASEB Office of Public Affairs Production Staff, Lawrence Green, Communications Manager, FASEB Office of Public Affairs Individualized Medicine: GENOMICGenetically Fine-Tuning Prevention, MEDICINEDiagnosis, and Treatment of Disease When Milwaukee geneticist and attacked gut microbes that century of progress by scientists Elizabeth Worthey first saw are usually harmless and critical in a number of diverse fields her 5-year-old patient, he was for digestion of food. Discovery that collectively deciphered the so stunted by malnourishment of this genetic defect led to structure and function of DNA she thought he was half his the boy undergoing a stem cell – the molecule that encodes age. By then the child had transplant that provided him with our genes. This molecule helps undergone dozens of operations a normal immune system and determine not only a person’s hair and extensive hospitalizations, cured his life-threatening bowel and eye color but what diseases almost died in intensive care, and disease. he or she may develop and had been given several courses Worthey’s ability to zero which treatments will work best. of intravenous drug treatments in on her patient’s medical DNA can even help determine for persistent inflammatory ailment and tailor therapy so the optimal dose to administer. bowel disease, which was first effectively is an example of By exploring answers to basic diagnosed when he was a baby. “individualized medicine” (also questions about microbes, cancer, Nothing was working. called “personalized medicine” the immune system, and other or “genomic medicine”). This biological processes, scientists Suspecting he was born with groundbreaking approach to have fostered the current genetic a genetic defect that caused his predicting, diagnosing, and revolution in medicine that is severe illness, Worthey searched treating disease is dramatically helping physicians find the right for all known genetic flaws in changing how many cancers treatment for the right patient at the boy’s DNA, but none of the and other diseases are managed, the right dose. genetic tests showed any likely preventing deadly side effects culprits. Finally, in 2010, Worthey from prescription drugs, and In search of the gene took an unprecedented step avoiding drug resistance in that ended up saving the boy’s This revolution began in the patients being treated for life and changing the practice middle of the 19th Century infections. of medicine—she deciphered when the Austrian monk Gregor the exact makeup of all of the Innovations in individualized Mendel conducted his famous boy’s thousands of genes that medicine come on the heels pea-breeding experiments and determine the proteins his cells of technological advances demonstrated that physical make. Proteins are the body’s that make it both feasible and traits, such as plant height and workhorses that execute all of its affordable to decipher a person’s pea color, are passed from one functions. By doing a complete complete genetic make-up. But generation to the next via units of analysis of the boy’s protein- the research developments that inheritance that later came to be making genes (exome), Worthey led to this fine-tuned way of called genes. But it was not until discovered a defect in a specific practicing medicine were not 1944 that Rockefeller University gene that explained why his so targeted themselves. Instead, bacteriologist Oswald Avery immune system went overboard they evolved from more than a showed genes were comprised of Breakthroughs in Bioscience 1 DNA. Avery realized this while They also recognized that the University of British Columbia, pursuing research to discover two strands could be separated deciphered the genetic code used why some strains of pneumonia for copying—a simple way to by all living cells to translate the are more deadly than others. pass on genetic information from series of bases in their DNA into one generation to the next. instructions for the production of thousands of proteins that [ A few years after Watson and determine cell structure and Crick clarified the structure of function. Nirenberg and Khorana DNA, biochemists Marshall discovered that the precise Nirenberg, at the National sequence of A, C, G, and T bases Institutes of Health (NIH), and on a DNA strand is the formula Har Gobind Khorana, at the that encodes the ordering of amino Figure 1 – In search of the gene: Gregor Mendel (left) showed with his plant breeding experiments that physical traits, such as the height of pea plants, were inherited. Later, Oswald Avery (right) discovered that genes were comprised of DNA. Photo credits: National Library of Medicine. Avery’s finding drove basic researchers from all over the DNA - 56858 world on a competitive chase to determine the precise structure of DNA and how it worked to pass Sugar on traits. This race ended in 1953 Phosphate Backbone when Rosalind Franklin at King’s College in London discovered that DNA contains two helically Base Pair twisted strands connected to each Nitrogenous other by a series of chemical Base rungs. That same year, James Watson and Francis Crick, then at Medical Research Council Guanine laboratories in Cambridge, Adenine Cytosine England, correctly surmised each Thymine rung was composed of one of two chemical base pairs: adenine (A)-thymine (T) or guanine Figure 2 – The structure of DNA: Rosalind Franklin (top) was the first to create an (G)-cytosine (C). Watson and image of a crystal of DNA. This image revealed that DNA is comprised of two helically twisted strands connected to each other by a series of chemical rungs. Then James Crick realized that it was the Watson and Francis Crick (bottom) recognized that specific pairing between the bases order of those A, T, G, and C A:T and G:C make up those rungs through hydrogen bonds that can be broken to peel bases on the DNA strand that apart the strands for precise replication, a critical property of DNA. Photo and image spelled out the genes in every credits: National Library of Science/Science Source (Franklin), From the Linus Pauling and The Race for DNA Collection, Special Collections & Archives Research Center, living organism and is the source Oregon State University (x-ray diffraction), A. Barrington Brown/Science Source of variation in physical traits. (Watson/Crick). Breakthroughs in Bioscience 2 acids linked together to create a protein. If the sequence has extra, Gene misspelled, or deleted bases, the cell can make the wrong protein or too much or too little of the DNA correct protein. transcription GCCTCACACTAG codon These mistakes, called CGGAGUGUGAUC mutations, can result in disease, mRNA Uracil (U) replaces although in some cases, thymine in RNA. mutations can actually protect people from developing specific translation disorders. Mutations in certain genes also play a role in making tRNA people more susceptible to the protein harmful effects of smoking or Arginine Serine Valine Isoleucine other environmental causes of disease, and in making microbes amino acids able to cause infections. (See Figure 3 – The genetic code: Marshall Nirenberg (top) and Har Gobind Khorana (bottom) “Knowing the Enemy” box discovered that the precise sequence of bases on a DNA strand is a formula that encodes insert.) In addition, genes shape the ordering of amino acids linked together to create a protein. Each triplet of bases on a how our bodies break down the DNA strand codes for a specific amino acid, and the entire formula for a protein is passed drugs we take to cure disease via messenger RNA to cellular machinery, which translates it into the specific protein. Photo credits: Ferald V. Hecht/National Institutes of Health (Nirenberg), UW-Madison or relieve its symptoms.