Melanoma stem cells are marked by a particular enzyme that could serve as a potent new target for treatment, a University of Colorado Cancer Center study concludes. The researchers, led by Mayumi Fujita, determined that the enzyme ALDH marks human melanoma stem cells, which can resist chemotherapy. But they countered this resistance and killed melanoma cells in cell cultures. Their secret: The scientists silenced the gene that creates a variation of the ADLH protein known as high-ALDH. In animal tests, this same process took away the ability of melanoma cells to form tumors. Details are published in the journal Stem Cells. Release