Metastasis, which occurs when cancer cells break away from the primary tumor and form a new one in other organs or tissues, is responsible for 90% of deaths from cancer. A new study published in the journal Nature indicates how a diet rich in palmitic acid – the main component of palm oil – alters the cancer genome and increases the likelihood that it will spread.
In this work, cells from oral tumors and melanomas from patients have been exposed to a diet rich in this acid and it has been observed that they have a greater capacity to metastasize in mice, even when this diet is administered for a very short period of time. . This is due to the fact that the modifications generated by the fatty acid on the genome of metastatic cells are permanent.
The authors, scientists from the IRB Barcelona led by Salvador Aznar-Benitah, believe that these results can be extrapolated to sick people: “We have seen with gene expression data from various types of cancer in hundreds of patients that the routes we have studied correlate with poor prognosis in several of these tumors “, he explains to SINC.
Cells from oral tumors and melanomas from patients have been exposed to a diet rich in palmitic acid and have been shown to have a greater capacity to metastasize in mice.
“It is still early days, but this suggests that the results are very relevant for cancer patients. The only way to verify this is through clinical trials and for that we would still need quite a few years,” adds Aznar-Benitah.
Researchers have identified a series of markers of palmitic acid exposure in tumor cells: a change that causes them to maintain a greater metastatic capacity, even months after being exposed to the fatty acid and that could be related to a greater capacity to these tumor cells to innervate.
“In 2017 we published a study on the fact that palmitic acid is correlated with an increased risk of metastasis, but we did not know the mechanism. In this we already detailed the process, we revealed that there is a ‘memory’ factor of metastatic capacity and we pointed out a pathway therapy to reverse it “, emphasizes Aznar-Benitah.
Experts have begun to develop therapies to interrupt this process: “What we are going to test from now on will tell us if some of these findings may have clinical potential.”
It does not happen with other types of oils
The results indicate that a diet rich in palm oil would be detrimental to the development of cancer, even if it occurs in a very early phase of the disease in which the primary tumor may not have been detected yet.
Scientists have observed that this expansive and colonizing capacity is acquired due to the consumption of palmitic acid (predominant in palm oil), but this is not the case with oleic acid (very abundant in olive oil) or linoleic acid (characteristic flaxseed).
These results suggest that aggressiveness not only has to do with fat metabolism, but also the epigenetic modifications that occur in tumor cells when they ingest palmitic acid.
The key to tumor expansion
In order for a tumor cell to metastasize, it must first shed the tumor of origin, enter the blood or lymphatic vessels, reach another vital organ, and survive and grow there. In this study, the authors have identified that a diet rich in palmitic acid allows tumor cells to create a neural network around the tumor.
The most metastatic tumor cells acquire the ability to call the nervous system and the neural network that forms around the tumor generates a regenerative environment, which the cells use for their own benefit, to grow and expand.
One of the key elements in the formation of the neural network that favors metastasis are the so-called Schwann cells, which surround and protect neurons. This new work shows that blocking Schwann cells in different ways inhibits the formation of this nerve network, and metastasis does not take place.
While the study is promising because it opens up new avenues for research and development of therapies specifically aimed at preventing metastasis, there are limitations
Work with limitations
Although for Salvador Aznar-Benitah the study is encouraging because it opens new paths for research and development of therapies aimed at preventing cancer metastasis, there are limitations.
“Although we work with tumors from patients, we are always transplanting them into immunosuppressed mice (if not, the animal would reject the tumor). Therefore, we have not been able to analyze the possible interaction between dietary fat, metastatic cells, nerves and the immune system “.
“We are now studying this in new models that we have established in the laboratory and that now allow us to analyze this potentially interesting aspect of metastasis”, he concludes.