Seminars & Lectures

“Long-label retention and asymmetric division: Are they related in mammary epithelium?”

  • By Dr. Gilbert H. Smith, Ph.D.- Head of the Mammary Stem Cell Biology Section in the Mammary Biology and Tumorigenesis Laboratory in the Center for Cancer Research, NCI
  • March 12, 2010
  • 1:00pm
  • Poole Agricultural Center, Room E142
  • Seminar is co-hosted by The Institute for Biological Interfaces of Engineering and
    Department of Animal and Veterinary Sciences

Biography of Dr. G. Smith:

Dr. Gilbert H. Smith received his Ph.D. in Biology from Brown University in 1965. He then came to the National Cancer Institute as a Staff Fellow in Research in the Ultrastructural Research Section of the Viral Biology Branch under the supervision of Dr. Albert J. Dalton.

Dr. Smith earned a reputation in the application of new research techniques to the analysis of viral and subcellular structures under the electron microscope. His research led to seminal papers describing the chemical ultrastructure in situ of the Mouse Mammary Tumor Virus (MMTV) and its putative nucleoprotein intracellular precursor in enzymatically digested ultrathin sections from mammary tumors embedded in water miscible plastic. Subsequently he developed new methodology for direct localization of viral antigens at the ultrastructural level employing biotin-labeled antibodies and horseradish peroxidase.

In 1970, Dr. Smith published the first three dimensional model of the nuclear pore-annulus complex which was derived from serial ultrathin sections of the nuclear envelope in cells embedded and sectioned directly from monolayer culture. This model in all its detail is identical to that used today to describe this important cellular organelle.

Currently, Dr. Smith is the Head of the Mammary Stem Cell Biology Section in the Mammary Biology and Tumorigenesis Laboratory in the Center for Cancer Research, NCI and has contributed significant advances to the understanding of adult somatic stem cells in the mammary gland, demonstrating that a single pluripotent mammary cell is capable of producing daughters sufficient to regenerate an entire functional lactating mammary gland and to be self-renewed among this population; capable of repeating this process over multiple generations. Dr. Smith has also defined two lineage-limited epithelial progenitors in the mouse mammary gland that exist downstream from the pluripotent mammary cell. In re-applying his expertise in electron microscopy, Dr. Smith has identified at the ultrastructural level, two undifferentiated mammary epithelial cell types that represent strong candidates for the morphologic counterparts of mammary epithelial stem cells. This supposition has received strong experimental support from recent studies in the human breast as well.

In 2006, Dr. Smith received an NIH Merit Award for his outstanding contributions to our understanding of the mammary stem cell niche in breast development and tumorigenesis, As the result of these advances, Dr. Smith has established himself as the leading international expert in the biology of mammary epithelial stem cells and has recently demonstrated that the signals comprising the mammary microenvironment can redirect the cell fates of testicular spermatogenic and neural stem cells in vivo.