In a retrospective study of breast cancer tumors lacking estrogen receptors, progesterone receptors and Her2, DiRenzo and his colleagues found extremely high amounts of nestin in 14 of 16 tumor samples examined. While the researchers plan to strengthen their findings with a larger prospective study, their results offer a crucial first step in diagnosis and management of a disease that is notoriously difficult to control. Consistent with other studies showing that breast cancers associated with inherited mutations in BRCA1 display the basal phenotype, DiRenzo and colleagues found high levels of nestin in these tumors as well.
Nestin is a long filamentous protein found in adult stem cells in the central nervous system. While scientists do not know its exact function, the protein is thought to have a role in stabilizing the structure of adult stem cells as they regenerate and divide into daughter cells.
"Normal basal epithelial tissue produces nestin, but basal epithelial tumors produce a tremendous amount of nestin, which likely represents an abnormal expansion of the basal epithelia." DiRenzo said. "If it is indeed specific to regenerative cells, then it will make for an excellent diagnostic tool for a cancer of regenerative mammary cells."
According to the DiRenzo, another important next step will be finding an efficient means of detecting nestin in a clinical screening setting. While it seems unlikely that a blood test would be sufficient, DiRenzo believes that a non-invasive test that collects samples from mammary ducts may enable the development of a screening tool for at-risk patients.
Source:American Association for Cancer Research