Heart Beating Inhibits Cancer Growth in Mice, Study in Science Reveals

Chong added that this latest study puts forward a compelling case that mechanical strain on the heart could be an explanation.

The findings build on observations that almost all organs and tissues in the body can develop tumours, but those affecting the heart are seldom observed. The study provides experimental evidence linking the heart's constant motion to cancer resistance. Zacchigna's team used genetically modified mice for the transplants, ensuring the external hearts maintained blood supply without beating.

This setup allowed direct comparison of cancer progression in beating versus non-beating cardiac environments. In the dish-based experiments, the reliance on calcium exposure to induce beating mimicked natural heart function, revealing how mechanical activity limits cancer cell invasion. Cancer cells in beating tissue remained confined, unlike in static conditions where they spread extensively.

Chong emphasized the study's implications for understanding cardiac oncology. He noted the long-standing puzzle of low tumor incidence in the heart despite its exposure to circulating cancer cells. The research highlights differences between primary and secondary cardiac cancers, with the latter being more common but still relatively rare compared to other organs.

Autopsy data underscores this disparity, with primary tumors under 1% and secondary up to 18%. By transplanting hearts to the neck, the team created a controlled model to isolate the beating mechanism's role. The rapid replacement of healthy cells in non-beating transplants contrasted sharply with the limited 20% cancerous tissue in native hearts.

Engineered tissues further confirmed that beating restricts cancer to outer layers, preventing deeper infiltration. This spatial distribution suggests mechanical forces create an inhospitable environment for tumor growth inside the heart muscle. The study, appearing in today's issue of Science, offers a mechanical explanation for a phenomenon observed across species.

Researchers injected lung cancer cells into the engineered tissues, observing greater proliferation in static conditions. Chong's comments provide expert context, affirming the study's contribution to resolving a key question in cardiology and oncology. The work involved interdisciplinary approaches, combining transplantation, tissue engineering, and cancer cell injection to yield these insights.