Colorful spy tactics track live cells supporting cancerous tumors

A new advance in cellular imaging is allowing scientists to better understand the movement of cells in the area around tumors, also known as the tumor microenvironment. In a recent article published in Disease Models & Mechanisms (DMM), dmm.biologists.org, Zena Werb and colleagues used optimized methods of laser microscopy to track the movement of live cells in a mouse model of breast cancer. As a tumor grows, it triggers immune responses in the body, and recruits assistance from normal cells in order to "feed" and support the spread of the cancerous growth. The influence of the tumor on nearby cells is dependent on the microenvironment surrounding the tumor. Some immune cells and structural proteins defend the body against the tumor, while others help the tumor grow and spread.

In order to watch the activity of these cells, researchers injected fluorescent dyes near tumors in mouse models of breast cancer which also expressed fluorescently tagged cells A specially designed microscope allowed live imaging of tumor-associated cells for more than 12 hours, while retaining the high resolution necessary to watch individual cells move in real-time. They saw that subsets of immune cells move differently – some migrate along blood vessels, while others remain at the border of the tumor. Additionally, changes in the tumor microenvironment, such as a reduction of oxygen, caused some immune cells to stop migrating.

This study sheds light on how certain immune cells help or hinder tumor growth. This in turn aids in identifying drug targets which can be inhibited to prevent the spread of cancer, or conversely, targets which can be stimulated to enhance the body's natural immune response to cancer. Additionally, this new imaging technique has potential beyond studying cancer, such as watching cell movement in other tissues and organs, both diseased and healthy.

Source: The Company of Biologists