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The completion of the human genome project has received widespread attention in the press. How will this milestone lead to a better understanding of cancer? Will this knowledge lead to better diagnosis and treatment of cancer?
The genome represents all the genetic material found in the chromosomes of an organism. 2Within each chromosome is a DNA molecule, which consists of two strands wrapped around each other. Each strand contains repeating units called nucleotides, composed of a sugar, phosphate, and a nitrogenous base. The two DNA strands are held together by weak bonds between the bases on each strand, forming base pairs. The particular order of bases along the DNA strand is known as the sequence. Genes are the basic units of heredity and are represented physically by segments along the DNA strand that contain specific sequences of bases. These segments represent the genetic code, with each triplet of bases coding for the formation of an amino acid, the building blocks of proteins. Leading scientists in the field of genome analysis conceived of analyzing the entire human genome back in 1985. 4The goal of 15 years was set, which seemed nearly impossible at the time, since it involved the analysis of 3 billion bases. However, the scientists realized that a more complete knowledge of all the genes and their locations on the human chromosomes would be invaluable in advancing biomedical research, so they obtained public funding to proceed. Advances in technology, as well as a rivalry with the private company, Celera Genomics, were instrumental in achieving the goal. One should keep in mind that the project just provides an analysis of the bases, and the identification of genes depends on further interpretation. Preliminary analysis indicates that the number of genes is surprisingly small, around 35,000. This represents only about 2% of the total base pairs, with the remainder being non-coding DNA, which may still play important roles. Complicating the issue is the fact is that many individual genes have non-contiguous segments, which are separated by non-coding regions. Application of genome knowledge to cancer treatment Recall that cancer is caused by malfunctioning genes, either through activation of cancer causing oncogenes, or through inactivation of tumor suppressor genes. The "reductionist" view of cancer treatment is based on finding the aberrant genes and blocking their effect. This view is exemplified by the rapid development of DNA microarrays. This procedure involves extracting tumor cells from the patient, and analyzing for thousands of active genes simultaneously. By comparing the active genes in the tumor to that of normal cells, the genes causing the cancer can be determined. In this manner, each person’s cancer could be considered unique, requiring personalized treatment. The treatment plan would have a more rational basis, as it would zero in on the specific cause of the condition, and only those treatments known to be effective for that specific condition would be chosen. In addition to traditional chemotherapy, a whole array of newly emerging therapies that I have discussed previously could be brought to bear. There is no doubt that the new knowledge of the genome will be valuable in developing these new methods of diagnosis and treatment. Go To Page: 1 2
The copyright of the article The genome project and cancer research in Cancer Treatment is owned by David Olle. Permission to republish The genome project and cancer research in print or online must be granted by the author in writing.
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