Penn Medicine study discovers new type of cancer immunotherapy

Penn Medicine has found a new type of cancer immunotherapy which significantly shrinks tumor growth.

In a recently published study, a research team at Penn's Perelman School of Medicine, which included researchers from other institutions, discovered they could block the production of immune suppressor cells and reduce tumors by inhibiting a certain molecule in human cells and in a mouse model, Penn Medicine News reported.

Proteins called checkpoints often prevent T-cells from killing cancer cells, according to Penn Medicine News. By blocking these checkpoints, checkpoint inhibitors allow T-cells to kill cancer cells, significantly reducing the size of tumors in mice. Using checkpoint inhibitors has shown survival benefits where traditional therapies such as chemotherapy do not work for some patients.

Penn Medicine researchers have been studying c-Rel, a specific type of molecule in cells, for two decades and were surprised to discover it plays a role in tumor growth as it was considered more to be a promoter of immune responses.

While researching c-Rel in inflammation and autoimmune diseases, the team discovered a relationship between c-Rel and myeloid-derived suppressor cells (MDSC), which were known to prevent the immune system from attacking cancer cells. This led to the finding of a previously unknown pathway for how cancer invades the body with the MDSC. 

The researchers found tumor cells would change the function of c-Rel to produce MDSC, which prevents the immune system from attacking cancer cells. 

With success in the preclinical setting, Penn Medicine News reported that the next step for this new immunotherapy is to assess the safety of the drug before moving forward with clinical trials.