Stem Cells, Vol 13, 336-343, Copyright © 1995 by AlphaMed Press
Selective elimination of malignant stem cells using photosensitizers followed by light treatment
JG Levy, C Dowding, D Mitchell, R Sorrenti, S Yip and C Jamieson
Quadra Logic Technologies Inc., Vancouver, British Columbia, Canada.
The pros and cons of purging of either bone marrow or peripheral blood stem
cell preparations for autologous transplantation for cancer has been
debated strongly over the past decade. Recent data implicating the role of
minimal residual disease in autografted marrow in cancer relapse have
renewed interest in this question. There is a considerable body of
literature supporting the possibility that photosensitizer molecules in
combination with light might provide a therapeutic window permitting
selective elimination of malignant stem cells while sparing those of normal
lineage. Molecules of this class are known to be taken up more actively by
most malignant cells, and intracellular concentrations are critical in
their cytotoxic effect when they are activated by light at an appropriate
wavelength. The present paper reviews the observations made over the past
decade on a variety of photosensitizers and their effects on hemopoietic
progenitors.
