In this section pharmacogenetics is discussed and how people can have very different responses to the same drug and treatment.
Pharmacogenetics Two people can have very different responses to the same drug and treatment. It is becoming clearer that the different responses relate to a person's genetic makeup. The treatment of breast cancer is one of the first to take into account a person's genetics. Her-2 is one example of a molecule that is different in different tumors. Her-2 binds to signals outside the cell, and triggers cell growth and division. Normal cells have very low levels of this protein; tumor cells often have high levels. Herceptin is a drug that targets Her-2. If a tumor is growing because of high levels of Her-2, tumor growth can be halted by Herceptin. On the other hand, if a tumorâ€™s growth is due to changes in a different protein, Herceptin will have no effect. Only 25 percent of breast cancers have high levels of Her-2 proteins. Giving herceptin to people with normal Her-2 levels has no effect on the cancer. As scientists learn more about the molecular basis of cancer, doctors will increasingly be able to tailor treatment to a specific individual. Microarrays are one tool that can be used to study the molecular profile of a specific tumor. Scott Lowe, Ph.D., Cold Spring Harbor Laboratory: â€œThis is some microarray data from a series of patients with sporadic breast tumors. Each row is an individual tumor and each column is a gene within this tumor.â€ â€œT he investigators in this particular study examined a microarray of about 25,000 independent genes and then selected a subset of these genes based on their ability to essentially classify the patients based on the probability with which the tumor will progress or metastasize.â€ â€œRed designates genes that have gone up relative to the reference standard, whereas green designates a gene that has gone down and the relative intensity of that color suggests the magnitude.â€ â€œOne thing that you can see quite clearly is that despite the fact that all of these are essentially cancers derived from patients with a very similar pathology, node negative breast cancer, the gene expression patterns just based on the intensity of the red and green are quite different.â€ â€œBased on this set of genes one can see big differences between the molecular pattern of these tumors and as these investigators noted, this correlates with the probability with which the disease will progress, within five years of being diagnosed. Why is this important? Clearly it shows that despite the fact that these patients have similar pathologies they're molecularly very different.â€ â€œThis information in the future could allow oncologists to decide whether or not additional therapy, for example chemotherapy, would be required. In the case of those patients that had the good prognostic gene expression pattern, would perhaps not require chemotherapy in addition to surgery and therefore they would be spared the devastating side effects of that therapy.â€ â€œBy understanding the natures of some of the genes that go up in these poor prognosis tumors it might be ultimately possible to design drugs that would specifically target these genes and then treat those cancers in a much more rational way.â€
sporadic breast tumors, cold spring harbor laboratory, molecular basis of cancer, treatment of breast cancer, breast cancers, cancer doctors, scott lowe, tumor cells, relative intensity, molecular profile, tumor growth, genetic makeup, breast cancer, herceptin, microarray data, metastasize, microarrays, genes
- ID: 1009
- Source: DNALC.IC
Use DNA arrays to determine the best treatment for breast cancer.
Matt Ridley talks about chromosome 13, BRCA2 gene for breast cancer susceptibility.
Pat Brown talks about using microarrays to discover the differences between cancer cells and healthy cells.
Scott Lowe's research has shown how the regulation of the cell cycle affect cancer.
Cancer is a disease that affects people of all nationalities and age groups and all cancers start with mutations in one cell.
Mary-Claire King speaks about how much was yet to be understood about the genetic mechanisms of cancer when she began her hunt for genes associated with breast cancer.
Denise talks about her family's affliction with inherited breast cancer and her decision to have her breasts removed as a preventive measure.
Genetic testing changed Denise's life.
The importance of cell death in cancer.
How do the cell death proteins interact?