Squeezed Cancer Cells Behave Badly
Cell replication is a complicated and highly regulated process that is greatly affected by the cell's environment. Past studies have focused on how a cell's chemical environment influences replication, but recently researchers have been interested in how a cell's mechanical environment is also a factor.
In order to study effects of the mechanical environment, scientists at UCLA designed an apparatus that confined cultured cells to a tight growing space. The researchers subjected the cells to two different levels of confinement (7 and 3 micrometers). They found that cancerous cells with genetic abnormalities became highly susceptible to replication abnormalities when confined. They discovered that confined cells (A) had more replication abnormalities overall, (B) had more multi-daughter divisions, (C) divided unevenly more often, (D) were more likely to die, and (E and F) took longer to replicate than unconfined cells.
The most surprising abnormality was the high incidence of multi-daughter divisions, where parent cells divided into three, four, or five daughter cells instead of the usual two. In the highest confined treatment, about 50% of cell divisions resulted in more than two daughter cells. (See micrograph.)
Because confined growing conditions is a property of tumors, the results of this study could contribute to our understanding of tumor growth.
Source: Tse HTK, Weaver WM, Di Carlo D (2012) Increased Asymmetric and Multi-Daughter Cell Division in Mechanically Confined Microenvironments. PLoS ONE 7(6): e38986. doi:10.1371/journal.pone.0038986