Michael M. Gottesman talks with
ScienceWatch.com and answers a few questions about
this month's Emerging Research Front Paper in the field of
Pharmacology & Toxicology.
Article: Predicting drug sensitivity and resistance:
Profiling ABC transporter genes in cancer cells
Authors: Szakacs, G;Annereau, JP;Lababidi, S;Shankavaram,
U;Arciello, A;Bussey, KJ;Reinhold, W;Guo, YP;Kruh, GD;Reimers,
M;Weinstein, JN;Gottesman, MM
Journal: CANCER CELL, 6 (2): 129-137 AUG 2004
Addresses: NCI, Cell Biol Lab, NIH, Bldg 37, Bethesda, MD 20892
USA.
NCI, Cell Biol Lab, NIH, Bethesda, MD 20892 USA.
NCI, Mol Pharmacol Lab, Canc Res Ctr, NIH, Bethesda, MD 20892
USA.
Fox Chase Canc Ctr, Div Med Sci, Philadelphia, PA 19111 USA.
Why do you think your paper is highly
cited?Does it describe a new discovery, methodology,
or synthesis of knowledge?
Resistance of cancers to chemotherapy, either intrinsic or acquired, is the
major impediment to the successful treatment of cancer. After over 40 years
of study, we are beginning to catalog the major mechanisms of multidrug
resistance, and this review summarizes the state of the field, summarizing
the work of many researchers over many years, and so represents a synthesis
of our current level of understanding of mechanisms of multidrug
resistance.
Would you summarize the significance of your paper
in layman's terms?
"We hope to determine which multidrug-resistance genes
are important in clinical drug resistance, and then design
approaches to circumventing or overcoming these forms of
drug resistance."
Oncologists won't be able to cure cancers that have spread unless they can
use drugs that specifically kill these cancer cells and spare normal cells.
Although many cancers are killed by chemotherapy, cancers are quite
heterogeneous and some cancer cells are able to survive treatment. These
cancer cells can grow and spread and kill our patients. If we can
understand why some cancers survive treatment, even very specific, targeted
treatment, we can improve the treatment of cancer.
How did you become involved in this research and
were any particular problems encountered along the way?
My interest in this problem began in the 1980s when it became clear that
there were some very effective anti-cancer drugs, but some cancers didn't
respond and others developed resistance. We set about to develop models of
multidrug-resistant cancers in cultured cells and use sophisticated
molecular techniques to isolate the genes whose expression conferred
resistance to the drugs.
Our first discovery, with my colleagues Igor Roninson and Ira Pastan, was
that multidrug-resistant cancers overexpressed a gene that encoded an
ATP-dependent transporter, termed P-glycoprotein, MDR1 or ABCB1. Although
this gene is frequently expressed in drug-resistant cancers, inhibiting it
had only minor effects on drug resistance in cancer patients, undoubtedly
because there are many other multidrug resistance genes.
In fact, ABCB1 belongs to a family of 48 human ATP-dependent transporters,
of which approximately 50% can confer resistance to one or another drug.
Plus, there are many other genes whose expression can confer drug
resistance. So now we are enumerating all of these genes (at last count,
there were at least 400) and trying to determine which play a role in
clinical multidrug resistance.
Where do you see your research leading in the
future?
We hope to determine which multidrug-resistance genes are important in
clinical drug resistance, and then design approaches to circumvent or
overcome these forms of drug resistance.
Michael M. Gottesman, M.D.
Chief, Laboratory of Cell Biology
Center for Cancer Research
National Cancer Institute
National Institutes of Health
Bethesda, MD, USA Web |
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