If we accept this picture of the cancer cell, the logical conclusion is that the overall differences between a normal cell
and a malignant cell are so great that the two can be easily distinguished. Yet a system based on a single marker such as
PSA will never be satisfactory, and an effective assay system will have to be based upon the simultaneous assessment of multiple
markers. It is not clear how such a system might be configured, but I would suggest that immunoassays that combine measurements
for several markers simultaneously might offer the possibility of an effective diagnostic. One appealing way in which such
platforms could be designed would entail the use of single-chain antibodies joined together as bivalent antibodies or "tetrabodies."14
It is a depressing reality that the tremendous strides in our understanding of the molecular laws governing living creatures,
which have fostered so much accomplishment and understanding in recent years, have not been accompanied by a concomitant introduction
of new therapies. In fact, the number of new drugs introduced into the market place has slowed, and the situation is even
worse if one looks at the number of truly new drugs introduced per year, versus copycat drugs and trivial modifications of
successful, already existent drugs (such as chiral products). While there are a number of explanations for this unpleasant
fact, certainly a large share of the problem rests with the conclusion that the classical approach of targeting a single molecular
entity with a single agent does not meet the challenge of conditions such as cancer, obesity, aging, and cardiovascular disease,
in which a whole network of functions has been profoundly altered.
This challenge can be met, but it may require a whole new level of understanding and a new paradigm of treatment.
K. John Morrow, Jr., Ph.D. , BioPharm International Editorial Advisory Board and president, Newport Biotechnology Consultants, 625 Washington Ave., Newport, KY 41071, 513.237.3303, Fax: 513.271.0744, email@example.com
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