A growing body of research is reshaping how scientists understand breast cancer—not just as a disease of rogue tumour cells, but as one that cleverly recruits the body’s own immune system to survive and spread.

A new review by researchers from two Indian universities explains how macrophages, a type of white blood cell meant to protect the body at sites of infection, can be “reprogrammed” by breast tumours to aid cancer growth and metastasis.

The authors of the review are Alisha Sinha of the Jaipur-based Banasthali University’s Department of Biotechnology, and Pranay Punk Pankaj and Ranjit Kumar of Nagaland University’s Department of Zoology. Their review was published in the Breast Global Journal.

Breast cancer, the most common cancer and the leading cause of death in women worldwide, accounts for almost 15% of cancer deaths in women, either due to metastasis or its drug-resistant nature. Many mechanisms involved in breast cancer metastasis focus on tumour cell activities. Macrophages normally act as the body’s clean-up crew, destroying harmful cells through phagocytosis, a process in which unwanted cells are engulfed and digested. However, within breast tumours, these cells often change their behaviour and become tumour-associated macrophages (TAMs)—immune cells that now work in favour of the cancer rather than against it.

What the study found

The study explains that macrophages can exist in different “moods” or states. One form, the M1 macrophages, attacks tumours and triggers inflammation to destroy abnormal cells. Another form, the M2 macrophages, focuses on tissue repair and calming inflammation. Breast cancer cells push macrophages towards this M2 state, which unintentionally helps tumours grow, spread, and hide from the immune system.

Once converted, these M2-type macrophages help tumours in several ways. They release chemical messengers called cytokines (small proteins that allow cells to communicate) that encourage the formation of new blood vessels—a process known as angiogenesis. These blood vessels supply tumours with oxygen and nutrients, allowing them to expand rapidly.

The macrophages also weaken the body’s defences. They suppress T cells, immune cells that would otherwise recognise and kill cancer cells. In addition, tumour cells display “don’t eat me” signals on their surface, preventing macrophages from destroying them and allowing cancer cells to survive unchecked.

Another critical role played by these altered immune cells is in reshaping the extracellular matrix—the supportive tissue surrounding cells. By breaking down this structure, macrophages make it easier for cancer cells to escape the breast and travel to distant organs such as the lungs or bones, a process known as metastasis.

What next

The authors highlighted that this ‘dangerous partnership’ between tumours and macrophages forms a self-reinforcing cycle: larger tumours attract more macrophages, which further accelerate tumour growth and spread.

Understanding this relationship could open new treatment options. Instead of targeting cancer cells alone, future therapies may aim to re-educate macrophages, switching them back into their tumour-fighting mode or blocking signals that turn them into cancer allies.

Ms. Sinha said checking the “betrayal” of immune cells could be key to slowing breast cancer progression and improving long-term survival.

“The downregulation or reprogramming of M2 macrophage differentiation could emerge as a viable strategy for reducing breast cancer progression and metastasis. Such approaches may support the development of targeted immunotherapies that complement existing treatment modalities, offering more precise and less toxic options for patients,” Prof. Kumar said.

GUWAHATI

Apple farm waste may soon help protect metal pipes, machinery, and infrastructure from corrosion.

An international research team led by Nagaland University (NU) has found a way to turn discarded apple leaves into a highly effective, eco-friendly corrosion inhibitor, offering up to 96.2% protection for copper in harsh chemical conditions.

The study, carried out in collaboration with the University of Science and Technology Beijing (USTB), shows that tiny carbon particles made from apple leaves can shield metals from corrosion without using toxic chemicals commonly employed in industry.

The authors of the study are Ambrish Singh of the NU’s Department of Chemistry and Yujie Qiang, Ye Zhang, Xinyang Liu, and Ying Jin of the USTB’s National Centre for Materials Service Safety. The former is a visiting professor at the USTB.

Their findings were published in the Journal of Alloys and Compounds, a leading international scientific journal.

Corrosion is a costly global problem, damaging pipelines, storage tanks, and industrial equipment in oil and gas, chemical processing, power generation, and other sectors. Conventional corrosion inhibitors often contain hazardous substances that pose risks to both the environment and human health.

The researchers found that their apple leaf-based solution, known as carbon quantum dots, performed exceptionally well even at low concentrations. In acidic conditions—where metals corrode faster—the material reduced copper corrosion by 94%, rising to 96.2% over time, levels considered highly promising for industrial use.

Explaining its practical value, Prof. Singh stated that industries operating in acidic environments face high maintenance costs and safety risks due to corrosion. “Biomass-based inhibitors like the apple-leaf material could extend the life of industrial equipment while being safer for workers and the environment,” he said.

Prof. Qiang added that the team used a green processing method to convert apple leaves into nanoscale carbon particles. These particles cling tightly to metal surfaces, forming a stable protective layer that blocks corrosive chemicals.

While the results are currently based on laboratory tests, the team plans to move toward pilot-scale trials and real-world applications, including combining the material with existing protective coatings

Calling the work a major step forward, Nagaland University Vice-Chancellor Jagadish Kumar Patnaik said the study shows how agricultural waste can be turned into a high-impact green technology. “Such innovations reduce dependence on toxic chemicals while addressing real-world industrial challenges,” he said.

Beyond corrosion protection, the research highlights the potential of waste-to-wealth solutions. By converting farm residue into valuable nanomaterials, the technology could support circular economy models and open up new income opportunities for farming communities.