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Lactation Protein’s Possible Cancer Role

The protein MCL-1 is critical for keeping milk-producing cells alive and sustaining milk production in the breast, according to research published in Nature Cell Biology. Without milk production, offspring cannot survive, making MCL-1 essential for survival of mammalian species.

Dr Nai Yang Fu of the Walter and Eliza Hall Institute (WEHI) said that MCL-1 levels increase dramatically in the breast within 12 hours of giving birth. “We were able to use very sensitive technologies to determine that stem cells and luminal cells were the breast cells that most critically rely on MCL-1,” Fu said. “Luminal cells are the cells that line breast ducts and respond to hormones during puberty, pregnancy and lactation. It now seems clear that MCL-1 is integral to the survival of these cells.”

WEHI co-author Prof Jane Visvader added that “MCL-1 is important for the survival of certain immune cells, and for the survival and growth of cancers including leukaemia and lymphoma. Stem cells and luminal progenitor cells both require MCL-1 for their survival. Our team has previously implicated both these cell types in some types of breast cancer, raising the question of whether MCL-1 is an important target for developing anti-cancer drugs.”

The research also found that a growth factor called EGF induces MCL-1 activity during lactation. “It will be important to determine whether this mechanism also operates in breast cancer, as this could reveal new ways of targeting the disease,” said co-author Prof Geoff Lindeman of WEHI.