Chemotherapy in breast cancer treatment boosted with localised magnetic fields

Researchers have developed a non-invasive method to improve the effectiveness of chemotherapy while reducing its harmful side effects using localised magnetic fields.

By applying brief, localised pulses of magnetic fields, researchers have demonstrated a significant increase in the uptake of doxorubicin (DOX), a widely used chemotherapy drug, into breast cancer cells, with minimal impact on healthy tissues.

This selective uptake enables more precise targeting of cancer cells, potentially improving treatment outcomes and reducing the adverse effects often associated with chemotherapy.

The study is the first to systematically show how pulsed magnetic fields enhance DOX uptake in cancer cells. The team also showed that this approach could suppress tumours at lower drug doses.

The team’s research builds on earlier work from 2022, which first revealed that certain cancer cells are more vulnerable to magnetic field therapy.

DOX is a commonly used chemotherapy drug for breast cancer. It works by binding to DNA components and disrupting cell replication and respiration, which then kills off cancer cells.

Despite its efficacy, it is a non-selective drug, which means it can also damage healthy tissues, leading to side effects ranging from mild to severe, including cardiomyopathy and muscle atrophy.

To address these challenges, NUS Medicine researchers developed a novel approach that uses brief pulses of magnetic fields to selectively increase DOX uptake into breast cancer cells.

Their study revealed the role of a calcium ion channel known as TRPC1, which is often found in aggressive cancers, including breast cancer. Magnetic field exposure activates TRPC1, enhancing its ability to facilitate the entry of DOX into cancer cells.

The researchers conducted experiments comparing the effects of the magnetic field therapy on human breast cancer cells and healthy muscle cells. They found that breast cancer cells took in significantly more DOX when exposed to magnetic pulses, while normal tissues were not targeted as much.

A 10-minute magnetic field exposure reduced the drug concentration needed for similar amount of cancer killing by half, particularly at low doses of the drug.

In contrast, healthy muscle cells did not show an increase in cell death in response to the combination of DOX and magnetic pulses indicating greater protection for non-cancerous tissues.

The team also demonstrated that reducing TRPC1 expression or blocking its activity eliminated this effect, which confirms the crucial role of TRPC1 channels in the process.

“Importantly, when we increased the amount of TRPC1, we observed an increase in DOX uptake — this means that TRPC1 can be used as a viable therapeutic target for aggressive cancers,” said Vinesh Krishnan Sukumar, first author at NUS Centre for Cancer Research (N2CR) under NUS Yong Loo Lin School of Medicine.

“What’s promising is that this mechanism works strongest at low drug concentrations, enabling us to target cancer cells more effectively while reducing the burden of chemotherapy on healthy tissues,” professor Franco-Obregón said.

With breast cancer remaining the leading cause of cancer-related deaths among women worldwide, the need for novel treatment strategies is urgent.

“The majority of women who undergo chemotherapy experience side effects from treatment, and in some cases, doses of chemotherapy need to be reduced, or in severe cases, stopped prematurely,” said research team member professor Joline Lim.

“Moreover, prolonged exposure to high-dose chemotherapy can also lead to drug resistance. This targeted approach represents an excellent opportunity to potentially improve treatment outcomes while preserving patients’ quality of life.”