Natural protein discovery may help predict and slow aggressive cancers

An international team of researchers has identified a naturally occurring protein that helps limit the progression of several types of cancer, offering new insights into how tumours develop and potentially opening the door to improved cancer diagnosis and future treatments

The study, led by researchers from the Centre for Cooperative Research in Biosciences (CIC bioGUNE) and the Institute of Biomedicine and Biotechnology of Cantabria (IBBTEC), was published in Nature Communications on 7 July 2026.

The research focuses on a protein called ASPA, which acts as a natural regulator within the tumour microenvironment, which is the network of healthy cells, blood vessels, immune cells and connective tissue that surrounds cancer cells.

Rather than targeting the cancer cells themselves, the study explores how changes in this surrounding environment can influence whether a tumour grows slowly or becomes more aggressive.

Tumour microenvironment

Cancer has traditionally been viewed as a disease driven by the uncontrolled growth of malignant cells. However, scientists now know that tumours depend heavily on nearby healthy cells, which can be reprogrammed to support cancer growth.

Among the most important of these are cancer-associated fibroblasts (CAFs). Under normal conditions, fibroblasts help maintain tissue structure and support tissue repair. During cancer development, however, they can be transformed into cells that encourage tumour growth, help cancer spread to other parts of the body, and reduce the effectiveness of some treatments.

Understanding how fibroblasts change has become a major area of cancer research because it could reveal new ways to slow or stop tumour progression.

ASPA acts as a natural brake

The new study found that ASPA plays a key role in preventing fibroblasts from becoming cancer-promoting cells.

As tumours develop, communication between cancer cells and surrounding healthy tissue gradually reduces the amount of ASPA produced. Once ASPA levels fall, fibroblasts lose an important regulatory mechanism and are more likely to transform into cancer-associated fibroblasts.

Researchers also discovered that ASPA suppresses TGFβ signalling, a biological pathway known to trigger the activation of these fibroblasts. Without sufficient ASPA, this pathway becomes more active, creating conditions that allow tumours to grow, invade nearby tissues and spread more easily.

To reach these findings, the research team combined laboratory experiments, biochemical analysis, animal studies and advanced single-cell sequencing technologies to examine ASPA’s role across multiple cancer types.

Potential for earlier detection

One of the study’s most significant findings is the link between low ASPA levels and more aggressive forms of cancer. This suggests that measuring ASPA could one day help doctors identify patients whose cancers are more likely to progress rapidly or metastasise.

While the research remains at a fundamental stage and is not expected to lead to immediate changes in patient care, it provides an important foundation for future studies. Scientists hope to determine whether ASPA could eventually be used as a biomarker to assess cancer risk or become a target for therapies designed to modify the tumour microenvironment.

Building on collaborative research

The study highlights the growing importance of investigating not only cancer cells but also the healthy tissues that surround them. By understanding how tumours manipulate neighbouring cells to support their growth, researchers believe new treatment strategies could emerge that complement existing cancer therapies.

The project brought together specialists in cancer biology, fibroblast biology and cellular metabolism from several international institutions. It was supported by the Spanish Association Against Cancer, the Spanish State Research Agency, the European Research Council, the “la Caixa” Foundation and the CRIS Cancer Foundation, with patient-donated biological samples playing a vital role in advancing the research.

Although further studies are needed before the findings can be translated into clinical practice, the discovery of ASPA’s protective role represents an important step towards a deeper understanding of cancer progression and the development of more personalised approaches to diagnosis and treatment.