Russian scientists develop experimental cancer therapy targeting dormant tumour cells

Researchers at the Institute of Cytology of the Russian Academy of Sciences have developed an experimental approach to cancer therapy that completely destroyed tumour sites responsible for metastasis in laboratory rodents.

The findings suggest a promising strategy for preventing cancer recurrence by targeting dormant tumour cells that often survive conventional treatment, reports the Ministry of Science, Science and Higher Education of the Russian Federation.

Metastases are secondary tumour formations that occur when cancer cells spread from the original site of the disease. These cells can travel through the bloodstream or lymphatic system to other parts of the body, forming new tumour foci. Eliminating such cells remains one of the main challenges in modern oncology.

Existing therapies, including chemotherapy, typically destroy the most active cancer cells. However, a smaller population can enter a dormant state, making them resistant to treatment. These inactive cells may later reactivate and trigger new tumour growth, leading to relapse and the spread of metastatic disease.

According to the research team, the newly proposed therapy combines two compounds and focuses on neutralising both active and dormant cancer cells.

“We developed a combined treatment strategy using two compounds. In experiments with mice, the method not only suppressed tumour growth but also eliminated dormant cancer cells that can cause relapse,” said Irina Guzhova, head of the Department of Molecular and Cellular Interactions at the institute and one of the study’s authors.

One of the substances used in the experiments was chloroquine, a medicine traditionally prescribed to treat malaria but increasingly studied for its potential anti-cancer properties. Scientists previously demonstrated its ability to interfere with tumour survival mechanisms by suppressing autophagy – a cellular process that allows cells to recycle damaged components.

While autophagy normally helps healthy cells maintain stability, in tumours it can protect dormant cancer cells and enable them to withstand chemotherapy. By blocking this mechanism, chloroquine reduces the cells’ ability to resist treatment.

The second compound used in the study was oxaliplatin, a widely used chemotherapy agent that effectively destroys active tumour cells but can simultaneously stimulate autophagy, allowing dormant cells to survive.

To test the approach, researchers conducted experiments using three cell lines of acute sarcoma as well as rodent models with intestinal carcinoma. When both compounds were applied simultaneously, only active cancer cells were destroyed, while dormant cells remained viable.

Scientists say the findings demonstrate the importance of treatment timing in overcoming tumour resistance mechanisms, experts claimed. The scientists believe the proposed strategy could form the basis for future therapies designed to prevent cancer relapse by eliminating the hidden cellular reservoirs responsible for metastasis.