A recent study led by Sarah Phillips, a doctoral student of genetics from the Sackler School of Graduate Biomedical Sciences at Tufts University, identified a specific transcription factor called SLUG and associated it with stem cell regulation and its role in differentiating whether breast cells develop into luminal or basal cells.
The study explains that understanding factors similar to SLUG is critical in understanding how cancerous growths develop in breast tissue, and how they evolve into different variations. Philips and her co-researchers are hoping their contribution to what is already known about breast cancer can lead to the discovery of better treatment options.
Utilizing several research locations, including the Department of Molecular Carcinogenesis, Science Park-Research Division, at The University of Texas MD Anderson Cancer Center, the investigator’s approach was to decrease SLUG’s expression within breast cells prior to classifying them as either luminal, basal, or stem cells. The team then employed a mathematical model to determine the rate at which these 3 categories of breast cells mutated into a different type of cell. The rates obtained were then compared with control cells and with those that had a reduced SLUG expression, leading to their findings of the transcription factor’s effect on luminal-, basal-, and stem-cell transitions.
The mathematical model’s results were applied to breast tissue samples from two groups of mice: a control group with a non-reduced SLUG expression, and another without SLUG expression. The samples were then studied for any alterations in cell structure, concentrations of luminal and basal cells, and presence of any stem cell activity.
The study’s results were published as follows: “The SLUG-deficient mice exhibited defects in breast-cell differentiation. The mammary glands of these mice had too many luminal cells and defective basal cells that had luminal-cell characteristics. The control group of normal mice had a normal ratio of luminal to basal cells.”
The SLUG-deficient mice showed defects in stem-cell function, Specifically, tumor formation and tissue regeneration was inhibited, an indication of defective stem cells, suggesting that SLUG was necessary to maintain normal luminal and basal cells within the mammary gland.
Additionally, “SLUG-deficient cells when transplanted could not regenerate the mammary gland of the mouse, suggesting that SLUG is necessary for mammary stem-cell function. Tumor formation was also inhibited in SLUG-deficient mice, suggesting that SLUG may affect stem-cell activity necessary for tumor formation.”
America’s breast cancer statistics is quite alarming. It is estimated that out of 8 women in the US, 1 will develop invasive breast cancer. Last year, about 232,340 new diagnoses of this type of breast cancer were made, with non-invasive breast cancer diagnoses amounting to nearly 65,000. Although research and development efforts on breast cancer have been aggressive, mortality rates have not been reduced, with 2013’s estimated deaths from this type of cancer amounting to just under 40,000 American women.
This news follows a previous report on highlighting research by an associate professor from MD Anderson who successfully secured funding for a clinical study on NeuVax, in the hopes that it would be effective in preventing breast cancer recurrence.