Then, normal human skin cells were seeded onto the melanoma-preconditioned matrix and were allowed to remain for several days.
After this period, the previously normal cells seeded onto the matrix preconditioned by the metastatic melanoma were reprogrammed to express genes (produce specific gene proteins) associated with a highly plastic cell type similar to the aggressive melanoma cells used in the study.
Removal of the "transdifferentiated" skin cells from the melanoma microenvironment caused the cells to revert to their original appearance.
"There were no significant genetic changes between normal skin cells grown on an untreated matrix and those exposed to a matrix preconditioned by human metastatic melanoma cells, further supporting the hypothesis that "epigenetic" induction of changes in skin cell gene expression is directly related to exposure to the metastatic microenvironment," the authors said.
Hendrix's co-researchers on the study were Elizabeth A. Seftor; Kevin M. Brown; Lynda Chin; Dawn A. Kirshmann; William W. Wheaton; Alexei Protopopov; Bin Feng; Yoganand Balagurunathan; Jeffrey M. Trent; Brian J. Nickoloff; and Richard E. B. Seftor, from Northwestern University; Harvard Medical School; Tgen; and Loyola University.