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Archive - Mar 11, 2011

Study Shows How Breast Cell Communities Organize into Breast Tissue

A study by researchers with the Lawrence Berkeley National Laboratory (Berkeley Lab) of the different types of cells that make up the human breast shows that not only do cells possess an innate ability to self-organize into communities, but these communities of different types of cells can also organize themselves with respect to one another to form and maintain healthy tissue. Understanding this ability of different types of cell communities to self-organize into tissue may help explain how the processes of stem cell differentiation and tissue architecture maintenance are coordinated. It might also lead to a better understanding of what goes wrong in cancer. Dr. Mark LaBarge, a cell and molecular biologist in Berkeley Lab’s Life Sciences Division, and Dr. Mina Bissell, a Berkeley Lab Distinguished Scientist also with the Life Sciences Division, carried out a unique study of normal human mammary epithelial cells that had been enriched into pools of the two principal lineages that make up breast tissue – the milk-producing luminals and the myoepithelials that blanket them. In healthy breast tissue, these two lineages organize themselves into an ordered bi-layer. To observe and quantify changes in the distribution of these cell lines with respect to one another over time, Dr. LaBarge, Dr. Bissell and a team of collaborators used a unique “micropatterning” technique, in which the cells were confined to a three-dimensional cylindrical geometry. “We demonstrated that while bi-layered organization in mammary epithelium is driven mainly by the lineage-specific differential expression of the E-cadherin adhesion protein, the expression of the P-cadherin adhesion protein makes additional contributions that are specific to the organization of the myoepithelial layer,” Dr. LaBarge said.

Single Cell Sequencing Reveals Over 400 Receptors in Type of Nerve Cell

Scientists at The Scripps Research Institute and University of Pennsylvania have found a way to uncover potential drug targets that have so far remained hidden from researchers' view. By applying the new method to a type of nerve cell critical to regulating body temperature, the authors found more than 400 "receptors" (structures that bind other molecules, triggering some effect on the cell) responding to neurotransmitters, hormones, and other chemical signals. This represents 20 to 30 times more receptors than previous studies had identified. The technique, described in detail in a review article in the March 11, 2011 issue of the journal Pharmacology and Therapeutics, may be applied to finding "hidden" receptors in other types of nerve cells, expanding the repertoire of potential drug targets for diseases ranging from schizophrenia to Parkinson's disease. "This technique will enable people to uncover many more drug targets," said Dr. Tamas Bartfai, chair of the Department of Molecular and Integrative Neuroscience at Scripps Research. "That may be a game changer for some diseases." Receptors found on cells are among the most important targets for the development of drugs because of the key roles they play in the communication circuits regulating various body functions. So far scientists have identified only a few of the receptors present on different types of nerve cells. Dr. Bartfai's group has long been interested in a class of nerve cells in the brain called "warm sensitive neurons." These cells sense and respond to changes in body temperature, acting like a thermometer inside the brain. As body temperature increases, warm sensitive neurons become more active, telling the body to bring its temperature down. Without this regulation, body temperature could reach dangerous levels, even leading to death.