Scientists discover molecule that helps cancer cells evade immune system

Immune therapy - where patients receive treatment that helps their immune system fight disease - is a growing area in fighting cancer. Now, a new study promises to make such treatments more effective - it has found a molecule called NF-kB that helps cancer cells evade the immune system.

Drugs that target the NF-kB molecule could lead to improved treatments for cancer.

Reporting in the journal Cell Reports, researchers at Ohio State University Comprehensive Cancer Center, and colleagues suggest immune therapy for cancer might be more effective if combined with drugs that inhibit NF-kB.

Their findings also show how interactions between cancer cells and non-cancer cells boost tumor growth.

It has been long known that NF-kB promotes cancer development by subverting apoptosis, an internal safety mechanism that otherwise would cause cancer cells to self-destruct. 

This study shows that NF-kB might coordinate a network of immune-suppressor genes whose products enable tumor cells to evade adaptive immunity.

Blocking NF-kB might make tumors vulnerable to attack

The team suggests blocking NF-kB might make tumor cells more vulnerable to elimination by the immune system.

In earlier work, the researchers had found NF-kB helps normal cells to repair faulty DNA, thereby stopping it from causing harm. But what puzzled them was how and why such a molecule might behave differently in cancer cells.

For their study, they observed how NF-kB behaved during tumor formation in live mice and the early stages of mouse embryo development.

They found that immune cells known as macrophages migrate into the tumor during the early stages of tumor development and, as expected, they release tumor necrosis factor to trigger cell death. However, it appears that NF-kB enables cancer cells to survive this.

NF-kB may also be involved in immune suppression

The researchers discovered NF-kB may also regulate a number of genes related to immune suppression. When they switched off one of these genes in cancer cells with active NF-kB, it killed the immune suppression influence and slowed tumor growth.

Overall, their findings demonstrate that NF-kB might play a pivotal role in enabling cells to evade surveillance by both innate and adaptive immune cells.

Funds from the National Cancer Institute of the National Institutes of Health helped finance the study.

Another area where immune therapy shows promise is in the treatment of advanced melanoma, where skin cancer has started to spread to other parts of the body. In June 2014, researchers shared news at a conference in Chicago, IL, of immune therapy trials for melanoma treatment that may improve long-term survival for patients with advanced forms of the disease.