Nature: How can scientists analyze lymph nodes to help cancer cells spread?

4, 2020 // -- Clinicians have known for decades that multiple types of cancer cells spread to the lymph nodes before spreading through the blood to distant organs, and scientists from institutions such as Southwest Medical Center recently explained why in a study published in the international journal Nature, as well as new targets for developing treatments to curb the spread of cancer.
Photo Source: In the UT Southern Medical Center article, researchers found that melanoma cells that pass through the lymph nodes cover a protective film, which allows them to survive high levels of oxidative stress in the blood and form far-end tumor tissue, which can spread to many cancer patients when it begins to spread to other parts of the body, when cancer cells at the primary tumor site spread through blood vessels or migrate through the lymphatic tubes before entering the bloodstream. Dr. Sean Morrison, an
researcher, said the researchers had previously focused on how cancer cells metaste through the blood, but had rarely studied the differences between cancer cells metastasis through blood and cancer cells metastasis through the lymph nodes, and the results of this paper showed that by metastasis of the lymph nodes or by providing protection from oxidative stress on melanoma cells during metastasis, it could promote the survival and spread of melanoma cells.
researchers revealed changes in the behavior of these melanoma cells when they were injected intravenously or into the lymphatic system in mice, and found that cancer cells injected directly into the lymph nodes survived better and were more likely to form tumors than melanoma cells injected directly into the body's blood in mice.
The researchers hypothesized that the high levels of oxidative stress experienced by cancer cells metastasis through the blood may explain this difference, and that exposure to oxidative stress in the blood may be one of the reasons why most cancer cells are less effective at metastasis, and that cancer cells may have died before they had a chance to grow at the far end.
researchers note that after an in-depth analysis, they found that oxidative stress in the blood promotes cancer cells to experience a particular form of cell death known as "ferroptosis", where cells in the lymph nodes experience lower levels of oxidative stress and protect themselves from "iron death."
To better understand why melanoma cells in the blood, rather than in the lymph nodes, experience "iron death," the researchers compared the metabolic differences between cancer cells in the blood and lymph nodes and found that the cells in the lymph nodes were called monounsaturated fats called oleic acid. Higher levels of acid, the main component of olive oil, and they also found that the monounsaturated fatty acid was also incorporated into the cell membranes of cancer cells in the lymph nodes, where diluted monounsaturated fatty acids inhibit chemical reactions that promote iron death and protect cells.
The protective membrane of lyphosphate from the lymph nodes may promote the safe entry of cancer cells into the bloodstream and "loop" to other points, eventually forming metastatic tumors, which may explain why cancer cells first form tumors in the lymph nodes before they pass through the blood to other far-end points, where they can be loaded with antioxidants to provide some protection when they enter the bloodstream.
Finally, researchers say, now we've revealed why cancer cells are more likely to metasexual first through the lymph nodes, which may hopefully help researchers develop new drugs that can effectively treat cancer patients by targeting protective mechanisms in the lymph nodes to inhibit early metastasis.
() Original source: Ubellacker, J.M., Tasdogan, A., Ramesh, V. et al. Lymph protects metastasizing melanoma cells from ferroptosis. Nature 585, 113-118 (2020). doi:10.1038/s41586-020-2623-z.