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Kaitlyn Felsheim
The nervous system is integral for communication between the brain and the rest of the body. It is responsible for relaying messages to breathe, eat, feel, blink, and perform other vital tasks. Neurons play a huge role in tissue development and specification, and it turns out that cancer cells might be using neurons to their advantage.
Because cancer cells divide and grow so quickly, their need for oxygen and nutrients is high. To ensure there are enough oxygen and nutrients to support this fast growth and division, cancer cells grow new blood vessels and draw nutrients from surrounding areas. Cancer cells also work to hide from the body’s immune response so that they can persist unmonitored. Now, a group of French scientists are postulating that cancer cells could even go one step further and recruit and manipulate a type of brain cell, called neuronal precursor cells or “progenitors,” to receive growth signals from the brain.
For a long time, the idea of a neuronal progenitor cell was a contentious one. But, after years of research, it became clear that these progenitors do, in fact, exist in the brain. Now, the question has become whether or not these neuronal progenitors can migrate to tumors to form a growth-inducing neuron-tumor connection.
Venkataramani et al. reported close communication between tumor cells and neurons in the brain. However, tumors might not need to be inside the brain in order to benefit from neurons. Currently, one hypothesis is that prostate tumors, as well as tumors in the gastrointestinal tract may recruit neuronal progenitors. Certainly if these tumors communicate with neurons it is possible that this research could be expanded to various other types of tumors as well.
Mauffrey et al. took small biopsies from human prostate tumors and found that they contained cells which expressed a molecule characteristic of neuronal progenitor cells, called DCX. This supported the hypothesis that prostate tumors do, in fact, communicate with neurons.
Next, the team of scientists took biopsies from three groups of patients: those with benign tumors, those with low malignancy tumors, and those with high malignancy tumors. The results showed that were more neuronal progenitor cells in high severity biopsies, which implied that neuron-cancer cell communication encourages growth and, in turn, malignancy.
Finally, Mauffrey et al. noted that in mice, the number of neuronal progenitor cells in tumors increased over time as the tumors grew. All of these results point to the possible recruitment of neuronal progenitor cells to prostate tumors, and can perhaps be extrapolated to other types of tumors as well.
These findings change the landscape with which we evaluate tumors. They also open a door to new therapeutic avenues. Now, there may be a new way to measure the severity of a cancer based on the level of neuron density within and around the tumor. Having a more complete picture of the ways in which a tumor thrives within the body will then allow for more personalized and effective treatment.
Edited by Sara Musetti
Works Discussed
Venkataramani, V., Tanev, D. I., Strahle, C., Studier-Fischer, A., Fankhauser, L., Kessler, T., . . . Kuner, T. (2019). Glutamatergic synaptic input to glioma cells drives brain tumour progression. Nature, 573(7775), 532-538. doi: 10.1038/s41586-019-1564-x
Hayakawa, Y., Sakitani, K., Konishi, M., Asfaha, S., Niikura, R., Tomita, H., . . . Wang, T. C. (2017). Nerve Growth Factor Promotes Gastric Tumorigenesis through Aberrant Cholinergic Signaling. Cancer Cell, 31(1), 21-34. doi: 10.1016/j.ccell.2016.11.005
Mauffrey, P., Tchitchek, N., Barroca, V., Bemelmans, A., Firlej, V., Allory, Y., . . . Magnon, C. (2019). Progenitors from the central nervous system drive neurogenesis in cancer. Nature, 569(7758), 672-+. doi: 10.1038/s41586-019-1219-y
Image Credits: https://www.maxpixel.net/Link-Nerve-Cells-Connection-3d-Abstract-Blender-1588720
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