Scientists from the US Duke University conducted their research using a specially modified polio virus. Analyses were performed on two human cell lines: the first was melanoma cells and the second was a culture of breast cancer cells. Both of these cell types were characterised by high expression on their surface of a certain protein, abbreviated as CD155. This protein is a receptor for the polio virus, and it is for this reason that the pathogen had an affinity for these tumour cells.

When the modified polio virus was introduced into the culture, the microorganism attached itself to the cells and led to the release of various antigens from within the cells. The human body contains many different antigens (such as the AB0 blood group system antigens), but the immune system - with the exception of autoimmune diseases - only attacks those antigens that are foreign to it. In the situation where cancer cells released their antigens, this phenomenon alone could stimulate the immune system to attack them. Such an outcome, however, was not the only one that occurred with the modified polio virus.

Indeed, the pathogen was characterised not only by its tendency to infect tumour cells, but, as shown in studies on mice, it also infected immune cells such as dendritic cells and macrophages. Eventually, the infected dendritic cells - whose role is to present foreign antigens to other cells and thereby stimulate them to fight off antigens that are foreign to the body - became active and stimulated an immune system response to tumour antigens.

The scientists observed that once the aforementioned phenomena had occurred, they persisted - thus significantly reducing the risk of cancer cells growing again. Whether cancer treatment using the modified polio virus will actually be used in oncology - this remains to be seen. However, it is certainly encouraging that science is learning more and more about how to treat cancer, which could definitely translate into more patients being cured of these diseases.