Cancer Cells and Immune Cells Compete for Vital Organelles

An international team of scientists from the Institute of Biotechnology of the Czech Academy of Sciences at the BIOCEV centre, the Faculty of Science at Charles University, and the Malaghan Institute of Medical Research in New Zealand has summarized the current state of knowledge on the horizontal transfer of mitochondria between immune and tumor cells in a newly published article in the prestigious journal Trends in Cancer. The authors focus on how this process may influence the course of cancer and what potential it may hold for future anticancer therapies.

Mitochondria are cellular organelles essential for energy production. Under normal circumstances, they are primarily inherited from the parent cell to daughter cells. In recent years, however, it has become apparent that, under certain conditions, some cells can also transfer them to one another. This phenomenon is known as horizontal mitochondrial transfer, or HMT for short.

Scientists at the Laboratory of Molecular Therapy, led by Prof. Jiří Neužil, have been studying horizontal mitochondrial transfer (HMT) for more than ten years. Thanks in part to their contributions, what was once a niche phenomenon has become a widely researched topic over the past decade, with implications for neurobiology, physiology, oncology, and countless other biological disciplines. An increasing number of studies are demonstrating how HMT influences the immune system’s ability to fight tumors. A newly published article synthesizes these new findings and places them in a broader context.

Tumors contain virtually all types of immune cells. It is precisely their ability to recognize and destroy cancer cells that largely determines the progression of the disease. The rapidly developing field of immunotherapy takes advantage of this by specifically targeting the enhancement of the antitumor immune response. Tumor cells, on the other hand, try to evade the immune system or weaken its effectiveness.

As the study’s authors summarize, most findings to date point specifically to the role of HMT as the mechanism by which cancer cells gain the upper hand. By “stealing” mitochondria from immune cells, the cancer cells deplete them. At the same time, the cancer cells can gain a new source of energy that helps them grow and spread to other parts of the body. However, the quality of the transferred organelles also comes into play. Instead of stealing them, cancer cells can “gift” immune cells with damaged mitochondria, thereby once again weakening the immune system and promoting tumor growth and development.

However, the situation is not black and white, and HMT can also be used to boost antitumor immunity. Cytotoxic T lymphocytes—the primary immune cells capable of eliminating cancer cells—can be strengthened precisely by the transfer of healthy organelles from stem cells. This transfer occurs when cells are co-cultured under laboratory conditions, i.e., in vitro. In their recently published article, the authors thus highlight the importance of further research into how tumor and immune cells compete with each other for mitochondria and the related potential of HMT—whether as a target or a tool—in the development of future immunotherapies. Further research will determine whether targeted promotion of HMT from tumor cells to immune cells can be utilized as part of anticancer therapy. 

Publication: Novak J, Hortova D, Endaya BB, Krulova M, Berridge MV, Neuzil J (2026) Horizontal mitochondrial transfer and the tug-of-war between cancer cells and immune cells. Trends Cancer, https://doi.org/10.1016/j.trecan.2026.05.008.