A new study by researchers at Memorial Sloan-Kettering
Cancer Center and Johns Hopkins provides fresh insight into
how tumor cells can become resistant to anticancer therapy.
The scientists observed that a protein called
P-glycoprotein, which causes resistance to chemotherapy in
many tumor types, is able to physically "jump" or transfer
between tumor cells and retain its functional properties,
protecting otherwise sensitive cells from the effects of
anticancer treatment. According to the authors, the
research is the first to demonstrate that a protein
transferred between cells retains its function long enough
to allow the recipient cells to survive potentially toxic
drug concentrations and ultimately develop intrinsic
resistance.
In other words, cells that would normally be sensitive
to treatment can develop resistance to it by receiving
P-glycoprotein from other cells, making chemotherapy much
less efficient. Uncovering the mechanism of this unusual
"jumping" of the protein between the cells can potentially
improve treatment success. The authors conclude that their
findings offer a new way in which to look at how cells
behave in a community of cells within a tumor mass. The
results have important implications for genomic analyses
within tumor samples because resistance to cancer therapy
can be achieved by protein transfer alone.
The new research was published last week in the online
Early Edition of the Proceedings of the National Academy of
Sciences.
The lead author was Andre Levchenko, formerly of
Memorial Sloan-Kettering Cancer Center and currently
assistant professor in the
Department of Biomedical
Engineering at Johns Hopkins. Levchenko is based at
Clark Hall on the Homewood campus.
The work was supported by the Department of Energy,
the Whitaker Foundation and Memorial Sloan-Kettering Cancer
Center.