By releasing chemical signals, the primary tumor will cause the “target” area to become adhesive, while also directing bone marrow cells to migrate there to “prepare the nest” for the arrival of cancer cells.
Researchers from Cornell University (USA) have recently discovered how secondary tumors form and can be controlled from initial cancer cells. Initially, the primary tumor releases growth factors that stimulate the formation of a sticky protein called fibronectin on the surface of healthy cells at the target area. Subsequently, a second batch of growth factors is released with the task of “tempting” bone marrow cells to move to this region. There, the bone marrow cells will aggregate into groups, creating a nest-like structure, waiting for malignant cells to arrive and form a secondary tumor.
According to this process, the research team believes that it is possible to control the movement of bone marrow cells using antibodies, as theoretically, this technique could be quite effective in cancer patients to prevent disease progression.
In experiments, all bone marrow cells in several mice were irradiated to destroy them, and then replaced with new bone marrow cells that had been tagged with green fluorescent protein, allowing researchers to easily track their movement under a microscope. Subsequently, these mice were injected with skin or lung cancer cells, each tagged with red fluorescent protein for tracking purposes.
It was anticipated that the cancer cells would first form a primary tumor on the skin and then spread to the lungs. Based on this, the research team observed that the green bone marrow cells appeared in the lungs several days before the primary cancer cells arrived. Following this, as “planned,” they reached exactly the location where the bone marrow cells were present.
Researchers then injected the mice with cultured cancer cells. Interestingly, the green bone marrow cells also migrated to the lungs first, demonstrating that any type of cancer cell secretes chemical factors into the surrounding environment to direct the movement of bone marrow cells.
According to the lead researcher David Lyden, the process of cancer metastasis can be prevented by controlling bone marrow cells with antibodies. The team hopes to begin clinical trials on patients within the next year.
