Cancer

The term fetal cell microchimerism (FCM) indicates the persistence of fetal cells in the mother for decades after pregnancy. These cells engraft the maternal bone marrow and are able to migrate through the circulation and to reach tissues in case of damage. In animal models, a beneficial effect of microchimeric cells in the repair of tissues after injury is documented. In humans, the possible role of fetal microchimeric cells is still controversial, particularly in the cancer field. At the peripheral blood level, FCM is less frequently observed in parous women affected with cancer than in healthy controls, suggesting a beneficial role in cancer surveillance. At the tissue level, several studies propose a protective and repair function for FCM, whereas others hypothesize a role in the progression of the disease. Interestingly, fetal microchimeric cells are able to transdifferentiate along different lineages. In particular, fetal cells expressing epithelial markers are hypothesized to have a repair function, those positive for hematopoietic markers to have a role in the attack of tumor cells, whereas those displaying an endothelial phenotype to favor tumor progression.