CHICAGO--Investigators at the John Wayne Cancer Center, Santa Mon-ica,
Calif, have discovered a lipid that appears to be unique to multidrug-resistant
Because the lipid, glucosylceramide, can be identified in a matter of
hours by lipid chromatography, it may provide an easy way of detecting
malignancies that will not respond to chemotherapy, Anthony Lucci, MD,
said at the Society for Surgical Oncology's Cancer Symposium.
Glucosylceramide was first identified in the MCF-7 doxorubicin-resistant
breast cancer cell line, Dr. Lucci noted, but was absent from wild-type,
non-drug-resistant breast cancer strains. It has been identified in two
other MDR cancer cell lines--KB-V-1 epidermoid carcinoma and OVCAR-3 ovarian
It also was found in all drug-resistant tumor tissue samples from a
group of AJCC stage IV melanoma patients and stage IV breast cancer patients.
In every case, however, the lipid was not present in tissue samples from
stage IV melanoma or breast cancer patients who had at least a partial
response to chemotherapy.
When the researchers assessed the rate of synthesis of glucosylceramide,
they found a ninefold higher rate of formation in MDR cell lines. They
concluded, therefore, that glucosylceramide is an attractive new marker
for multidrug resistance. "It is not something that usually accumulates
in cells, but it is found in all MDR cell lines tested and in patients
with a clinical history of unresponsiveness to chemotherapy," Dr.
He noted that this pilot study involved a small number of patients,
and the marker is currently being evaluated prospectively in a larger number
of advanced-stage breast cancer patients.