What is generally thought of as the reason of the rapid growth of cancer cells might not be that accurate, says a new study published in Cell Chemical Biology.
What accounts for the uncontrolled growth of cancer cells? A team of researchers led by Gary Patti, associate professor of chemistry at Washington University based in St. Louis, has come up with an additional explanation.
Researchers have attempted to explain the rapid division (and thus propagation) of cancer cells in terms of how they take in glucose from the blood — according to this theory, cancer cells load themselves with glucose to be able to synthesise lipids to make cell membranes, and other cell components as they divide to make more cells.
The glucose hypothesis has been backed by evidence ever since the 1970s. Scientists of that time had demonstrated how the majority of lipids in cancer cells came from the very glucose taken up by the cells; they showed this by making use of radioactively-tagged glucose. But, is this really what fuels the growth of cancers and tumours?
Patti’s work suggests that this hypothesis only happens in standard cell-culture medium that is rich in nutrients, and with only little lipid content. His research shows that fibroblasts proliferating will use glucose to make most of their lipids under such conditions. On the other hand, if lipids are added to the culture medium to match the concentration thereof in blood, the cells will preferentially use these lipids instead of making them themselves; furthermore, these cells will not take any more glucose.
When this effect was tested in two cancer-cell lines, it was found that they would respond in a similar way to lipids.
Patti reiterates the fact that cell cultures remain artificial systems that might generate results that are misleading.
These findings, therefore, challenge cancer research dealing with this topic, specially pertaining to treatment that focuses on the glucose theory. Patti explains that the latter is the “basis for how we diagnose cancer and manage its treatment in the clinic”. For instance, patients are diagnosed for cancer by analysing images of organs taking in glucose uptake. The new research points at the sensitivity of these scans: what if cancer cells require lipids instead of glucose? If this is the case, these cancer cells would go unnoticed if this diagnosis method is chosen.