“This study has unlocked one of the key survival factors in the mammary gland,” said Professor Jane Visvader from the Walter and Eliza Hall Institute in Australia. “MCL-1 is important for all stages of breast development, from puberty to pregnancy and lactation. Based on this discovery, it is reasonable to believe that every mammal requires MCL-1 for milk production and, ultimately, the survival of their offspring,” Visvader added.
According to researchers, MCL-1 levels increased significantly 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,” Dr Nai Yang Fu from the institute 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,” said Yang Fu.
The discovery further underscored the importance of MCL-1 for cell survival, Visvader said.
“In addition to our discovery, a number of recent research studies at our institute have shown that MCL-1 is important for the survival of certain immune cells, and for the survival and growth of cancers including leukaemia and lymphoma,” she said.
Professor Geoff Lindeman from the institute said the research also identified that EGF, a growth factor which works in tandem with MCL-1 during lactation.
“EGF has emerged as a key inducer of MCL-1 at the switch to lactation,” he said.
The study was published in the journal Nature Cell Biology.