Salmonella bacteria as a tool in the fight against cancer

Italian scientists have demonstrated for the first time that Salmonella bacteria, safe for humans in small doses, can stimulate the immune system and help the body fight cancer cells. Researchers from the University of Milan discovered that in the early stages of tumor development, the body can independently control cancer cell growth thanks to the protein connexin 43, which forms special connections between cells.

The protein connexin 43 allows cancer cell proteins to penetrate immune cells, which recognize them as foreign and initiate the destruction process. However, as the tumor grows, synthesis of this protein decreases, helping cancer cells evade immune surveillance. It is at this stage that intervention with Salmonella can have a significant effect.

In experiments on human and mouse melanoma cells, as well as on animals with existing tumors, the scientists injected Salmonella directly into cancerous tissue. This resulted in the restoration of connexin 43 synthesis and intercellular junctions, which made the tumor visible to the immune system and initiated its destruction.

"The bacteria activate the antimicrobial response of cancer cells, which quickly allows the immune system to detect and destroy tumor cells. This process also affects metastatic cells, reducing the risk of cancer spreading throughout the body," explains study leader Maria Rescigno.

The advantage of this approach is that it aims to strengthen the body's natural defenses, rather than directly destroying the tumor. Unlike traditional chemotherapy or radiation therapy, this method may be gentler and potentially less toxic to healthy tissue.

The next stage of research is to study the effectiveness of this technique for different types of human cancer. The scientists plan to confirm that the safe use of Salmonella could be a promising addition to existing treatments and open new possibilities in cancer immunotherapy.