By John Pawlek, PhD
More than 25 years ago the late Prof. Lynn Margulis at the University of Massachusetts, Amherst sent me a 1911 article by German pathologist Otto Aichel who proposed that metastasis might be initiated by hybridization between macrophages and cancer cells, with the daughter cells “thrown out of the path of the mother cells resulting in an entirely new cell having the characteristics of both mother cells to form what has come to be known as a malignant cell.”
The BMDC-cancer cell fusion hypothesis. A motile BMDC (red), such as a macrophage or stem cell, is drawn to a cancer cell (blue). The outer cell membranes of the two cells become attached. Fusion occurs with the formation of a binucleated heterokaryon having a nucleus from each of the fusion partners. The heterokaryon goes through genomic hybridization creating a melanoma–BMDC hybrid with two gene expression patterns conferring deregulated cell division and metastatic competence to the hybrid (1).