The secret of breast cancer recurrence has been discovered
Despite the constantly improving results of breast cancer treatment, many patients who have undergone therapy are worried about the possibility of a return of the disease. The fact that malignant diseases can recur months or even years after the successful completion of treatment has long been a mystery to doctors and researchers.
Recently, experts from the Medical College of Texas A&M University found that cancer cells go into a latent state after they absorb, in fact, "eat", the body's own stem cells.
The authors conducted experiments to study the interaction between breast cancer cells and bone marrow stem cells, known as mesenchymal stem cells (MSCs). In a three-dimensional culture, they observed how mesenchymal stem cells surround cancer cells, forming cancer spheroids. After that, mesenchymal stem cells inexplicably disappeared from the culture, which greatly puzzled the researchers.
Further observations showed that breast cancer cells were "cannibalized", that is, they absorbed mesenchymal stem cells. This increased the survival rate of cancer cells in conditions of nutrient deficiency, while suppressing their oncogenicity, which indicated the entry of cells into the resting phase. Transcriptome analysis of these cells demonstrated their unique molecular profile loaded with factors promoting survival and suppressing tumor growth, as well as inflammatory mediators characteristic of the secretory phenotype of cells that have entered the phase of physiological aging.
After analyzing the collected data, the authors came to the conclusion that in the conditions of the body, breast cancer cells can behave in a similar way, which explains the recurrence of tumors.
Cancer cells that have absorbed MSCs are highly resistant to chemotherapy and nutrient deficiencies that effectively destroy other malignant cells. Since these cells are isolated, they are not detected using existing diagnostic methods, and in favorable conditions they "wake up" and form a new tumor. Since a new tumor is formed from treatment-resistant cells, cancer recurrences tend to be much less amenable to therapy than the primary tumor.
The authors hope that the mechanism they have uncovered can help in developing an approach that keeps such "cannibal" cells at rest, preventing their awakening throughout the patient's life. It is also possible to create drugs that prevent the absorption of mesenchymal stem cells by cancer cells. Currently, researchers are studying the cannibalistic activity of various tumor cells and are considering the possibility of using mesenchymal stem cells as carriers to deliver toxic agents to cancer cells. In addition, a more detailed study of this phenomenon will help to understand the mechanisms of an equally mysterious phenomenon known as tumor latency.
According to one of the authors of the study, Dr. Thomas J. Bartosh, confirmation that the described mechanisms actually occur in the body of cancer patients can make significant changes in the treatment strategy of malignant tumors.
Article by Thomas J. Bartosh et al. A Cancer cells enter dormancy after cannibalizing mesenchymal stem/stromal cells (MSCs) is published in the journal Proceedings of the National Academy of Sciences.
Evgeniya Ryabtseva
Portal "Eternal youth" http://vechnayamolodost.ru based on the materials of Texas A&M College of Medicine: A possible explanation for recurrent breast cancer.
22.11.2016