Fortunately, this discovery can be used to boost the effectiveness of immune-based therapies to fight cancer.
Dr. Sharon Kuss-Duerkop, a research instructor working in the lab of CU Cancer Center investigator Dr. Dohun Pyeon, said that causing cancer may be a side effect of viruses manipulating the immune system.
Viruses "edit" human DNA via the insertion of their own genetic code into the DNA so that new viruses are created when the DNA is replicated. But the scientific review detailed that viruses can't actually "turn off" the immune system when it manipulates genes.
Viruses actually "mute" the immune system through epigenetic regulation. Instead of changing the actual code of genes, viruses modify how genes are expressed.
Viruses modify gene expression through DNA methylation. During this process, parts of the human genome become unreadable. When this happens, sections of the genome called DNA promoter regions are methylated.
These promoter regions act as on-off switches for next-door genes, and when a promoter region is methylated, this switch is turned off. The gene it controls isn't read and expressed.
Dr. Kuss-Duerkop explained, "You get lack of access by things that would be driving transcription."
This means that methylating DNA promoter regions allow viruses to turn off genes. However, the virus alone can't do this. They enlist human proteins which then methylate DNA to turn off the other crucial sections of human DNA.
Dr. Kuss-Duerkop added that viruses encode certain proteins that are able to regulate DNA methyltransferases. In essence, viruses make human proteins over-methylate human DNA.
Viruses target genes that the immune system uses to fight the virus itself, such as interferon-b, "a highly anti-viral gene expressed in virtually all cell types; or genes that T cells need to recognize virus-infected cells." (Related: Boosting immune system with natural methods offers many health benefits.)
This results in a weaker immune system fighting off the virus, and – if it's a cancer-causing virus – a "microenvironment" by the tumor where the immune system is suppressed. This occurs in various cancers, and tumors may even hide themselves from the immune system. Tumors can even suppress the immune system more globally by the places they grow.
To prevent these cancer-causing viruses from spreading and halting their ability to manipulate the immune system, medical experts are looking into a way that will allow the immune system to fight off cancer. They hope to do this by boosting the immune system's resistance to these same cancers.
Researchers are already making progress. For instance, PD-1 inhibitors can negate the "cloak" that cancers use to fool the immune system. Meanwhile, CAR-T cell therapies rely on specially engineered T-cells to target cancer-specific proteins and eliminate the cancer cells that they are attached to.
However, immune-based therapies against cancer aren't that easy to create. There's also the fact that not all patients will respond to these therapies.
To boost the effectiveness of immune therapies, or even identify which patients can benefit the most from immune therapies, experts must learn how viruses and cancers have evolved to circumvent the immune system.
It's possible that if virus-related cancers have methylated DNA promoter regions of immune-related genes, demethylating these genes can help boost the effectiveness of immune-based therapies against cancer.
Kuss-Duerkop noted that caution is advised to avoid turning down methylation globally, which may cause the over-activation of all genes in the cell. Instead, demethylating certain gene promoter regions selectively can help restore an immune system inactivated by cancer-causing viruses.
Viruses are causing these tumors to form, and they also control the immune system to allow tumors to keep growing. Dr. Kuss-Duerkop concluded that these same mechanisms can help prevent tumors via immune-based therapies. They may even prevent cancer from developing in the first place.
To strengthen your immune system so it can fight cancer, try to eat more of the foods below:
You can learn more about cancer and how to boost your immune system at Cancer.news.