Tumors obtain nutrients and oxygen by harnessing the surrounding blood vessels and making new vessels. Since there typically aren't enough nutrients and oxygen to support tumor cells, an uneven distribution of these substances is created inside and around the tumor mass, Cristini said.
The research of Cristini and colleagues, who worked in collaboration with Elaine L. Bearer, M.D., Ph.D., professor at the Brown School of Medicine, suggests that tumor growth and invasion could be predicted by using biophysical laws that link the effects of the uneven distribution of cell nutrients and oxygen to overall tumor behavior.
For different values of the input parameters, the model consistently reproduced the patterns of tumor invasion observed in experiments and in patient tumors, Cristini said. The patterns were regulated by changes in cellular characteristics, causing more aggressive tumor cells to invade the healthy tissue. As cancer cells invade and replicate themselves, they make the tumor shape unstable and more invasive. The model correctly predicted the different types of invasion under a variety of conditions.
The model further predicted that the different forms of cancer invasion correspond to different stages of tumor progression, Cristini said. In regions of low oxygen, these changes may include a slowdown in cell replication and heightened cell migration, which can result in a "single-cell file" invasion pattern. As cells aggregate in regions that have better access to nutrients and oxygen, migration is lessened and cell replication is resumed. This leads to the formation of wave-like patterns of cell rearrangements at the tumor boundary and the formation of round infiltrative "fingers" that can detach from the tumor as clusters of cells.
In the second paper, working in collaboration with Mary Edgerton, M.D., Ph.D., associate professor of pathology at The University of Texas M. D. Anderson Cancer Center, the research
|Contact: Robert Cahill|
University of Texas Health Science Center at Houston