Sheets of highly organized epithelial cells line all the cavities and free surfaces of the body, forming barriers that control the movement of liquids and cells in the body organs. The organized structure of normal breast epithelial cells may also serve as a barrier against cancer, according to a study by University of Helsinki scientists. The work appears this week in the online edition of the Proceedings of the National Academy of Sciences (PNAS).
Finnish researchers found that the tightly organized architecture of mammary epithelial cells is a powerful restraint against the cancer gene provoked inappropriate proliferation. Their study also links function of a tumor suppressor gene to the development of cancer gene resistant epithelial organization.
"Rogue cancer genes can force epithelial cells to proliferate and proliferation of malignant cells will certainly disrupt the organized epithelial structure. However, there has always been this chicken or the egg problem: Does cancer gene initiate cell proliferation, which causes disruption of the epithelial structure or does loss of tissue structure come first, creating suitable environment for cancer genes to enforce the cell cycle progression"" explains the research team leader Juha Klefstrom, Ph.D. The present study supports the idea that loss of tissue structure comes first.
Experiments with fly models have shown that loss of epithelial organization can enhance the tumorigenic potential of cancer genes (oncogenes) and these findings prompted Juha Klefstrom's team to explore whether the formation of epithelial organization works other way around and suppresses oncogene function. "We were amazed to find out that the formation of organized mammary epithelial architecture in three-dimensional organotypic cell culture correlated with complete loss of oncogenic activities of c-Myc cancer gene" says Klefstrom.
Johanna Partanen, a graduate student in Klef
|Contact: Juha Klefstrm|
University of Helsinki