Basic biomedical research forges new treatments for leukemia and

One of the most frequently asked questions of someone who conducts biomedical research is, "How does this basic information lead to treatments or cures for human diseases?"
There are no simple answers, but two thoughts came to me recently. Often a basic researcher will discover a new gene in a particular human cell. One of the ways a new gene is studied is to study its expression in normal cells. Then, scientists look at a number of cancers to determine if the new gene is expressed in any of them.
Imagine a new gene discovered in a normal brain. In screening normal tissue from humans (usually we use cell lines), or mice, we might discover that this gene is also present in the bone marrow.

This unexpected distribution of a gene in brain and bone marrow would lead investigators to screen several types of leukemia, as leukemias are tumors of the blood forming cells and generally arise in the bone marrow.
Continuing the scenario, we now find that this new gene was expressed in one type of leukemia (leukemias are broadly divided by the cell of origin, i.e., myeloid, lymphoid), and that only certain types of lymphoid (lymphocyte) leukemias express the gene. We would now study how the expression of the new gene correlated with our current classification of lymphoid leukemias.
Let's say, for example, it was found in many, but not all, of the lymphocytic leukemias that we currently classify as "chronic lymphocytic leukemia." Next, we would look at the case histories of those who had this diagnosis, and who did or did not express the gene. Often, what is found is that the expression of the new gene correlates with outcome: either expression of the new gene signifies a worse or better prognosis. Immediately, if this true, it becomes a "new" diagnostic test that doctors can use to predict the course for patients.
Why is this important? In the most practical sense, it helps doctors decide if more or less vigorous treatment is warranted. All treatments for leukemia, for example, are hazardous. If we knew that certain patients were at a much lower risk for treatment failure, we could use fewer drugs, less often, or some different method. This would allow us to tailor our treatment to the severity of disease -- knowing the circumstances upfront rather than at the end of treatment.
Countless examples of this approach are currently in use: estrogen receptor density in breast cancer; oncogenes in types of leukemia; prostate genes in prostate cancer, etc.
However, an even more important direction is possible -- discovery of a new treatment. An excellent contemporary example is the Her- 2/neu receptor in breast cancer. It was disovered that this gene was over-expressed in certain breast tumors. Later it became a prognostic (predictive) test for breast cancer. About five years ago, tests for the Her-2/neu receptor were being used to help determine the course of therapy. Now, in a recently approved drug, an antibody directed against the Her2/neu receptor is being used to treat certain breast cancers.
Preliminary results suggest that this will be an important addition to the current "cocktail" approach to the treatment of this dread disease.

Dr. J. Donald Capra is the president and scientific director of the Oklahoma Medical Research Foundation.

Article from :
http://findarticles.com/p/articles/mi_qn4182/is_19990818/ai_n10130044