Strange question, but not really. There is a subconscious assumption that a cancer is made up of . . . . . cancer, and only cancer. This would imply that if a cancer were made of billions of cells, then all 100% of those billions of cells would be cancer cells. “Well of course, what else would there be?”
A cancer like any other organ or living tissue needs oxygen, other nutrients and a means of eliminating waste products. This is the function of blood vessels, and it is true that a cancer has blood vessels. And there are other participants. Is a tree made up ONLY of leaves? The leaves are supported by branches and ultimately by the trunk. In the same way, the cancer cells need to sit on some scaffold or supporting structure. Fibroblasts provide this framework. In addition, there are the immune cells that are infiltrating the cancer, either trying to attack the cancer cells or being re-programmed to defend the cancer.
13 years ago, a colleague of mine (Dr. Taturo Udugawa) and his associates figured out what proportion of a tumor is actually made up of cancer cells. To do this, they created a lineage of mice that glowed green under violet light, by inserting the green fluorescent protein (GFP) gene into the mouse’s DNA. All of the mouse’s cells contained the GFP gene and glowed green under violet light. Then they injected non-GFP cancer cells under the skin of this GFP-mouse. When the tumor grew to a decent size, they cut it out and digested and broke down the tumor into single cells and counted all the cells. It turned out that 60-70% of the cells were not green (these were the cancer cells). The remaining 30-40% of cells glowed green (these were the normal, non-cancerous cells). So at least in this experiment, if you have a tumor, specifically Lewis Lung Carcinoma, you can know that 60-70% of the tumor mass is made up of cancer cells. The remaining 30-40% of the cells are there mainly to support the cancer cells.
This raises an important question in cancer research. “Is the treatment you’re trying to develop, aimed at the cancer cells or the non-cancer cells?” At Daniel 2:28, we strive to discover treatments that target the non-cancer cells, which we consider to be the Achille’s heel of the tumor. A future blog will explain more about these two different components of the tumor and why we intentionally target the non-cancer cell component.