SEP 18, 2021 8:36 AM PDT

Cancer Genes Might Aim for the Immune System, Not Growth Promotion

WRITTEN BY: Carmen Leitch

The DNA in our cells can accumulate damage over may years. Environmental influences like UV light or cigarette smoke may exacerbate the problem, but since cells have to replicate the genome every time they divide (and some cells divide many times thoughout a lifetime), it's been thought that genetic mutations naturally happen as we age. When those mutations occur in genes that suppress the growth of tumors, or keep cell division under control, cancer can happen. But now, researchers have found that many cancer-linked genes are actively involved in suppressing the immune response to cancer. Genes that have previously been associated with cancer may be playing a different role in influencing the development of disease than we knew.

e) / Credit:Public domain / Dylan Burnette and Jennifer Lippincott-Schwartz, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health

Reporting in Science, researchers found 100 mutations that can stop the immune system from identifying and responding to cancer. “The shock was that these genes are all about getting around the immune system, as opposed to simply saying 'grow, grow, grow,'" said study leader and geneticist Stephen Elledge, a Howard Hughes Medical Institute Investigator (HHMI) at Brigham and Women’s Hospital.

Researchers know that cancer can evade the immune system, which is why immunotherapies and checkpoint inhibitors were developed. The immune system has to be carefully regulated so it won't respond uncontrollably to infection or cancerous cells and cause massive inflammation. So the body uses immune checkpoints. Inhibitors remove those immune brakes. Immunotherapy that uses gene editing can also prime the immune defenses to fight cancer. But these treatments don't always work, and some have serious side effects.

In this study, CRISPR tools were used to edit 7,500 genes, and examine the effect when tumor cells carrying these mutated genes were put in a mouse model. One type of mice had a functional immune system, while another group did not. When tumors grew in the mice, the researchers used genetic sequencing to identify the genes in the tumors that were most mutated, which revealed how the tumor cells had continued to evolved once they were in the live model. This revealed that defective tumor suppressor genes often appeared in the tumors; there was a selective pressure on the tumor cell genomes that would enable those with mutated tumor supressor genes to continue to grow.

One gene in particular, GNA13 was found to shield cancer cells from the T cells of the immune system, when GNA13 carried mutations.

Elledge suggested that there is an ongoing evolutionary battle between cancer and the immune system, with tumor cells armed with hundreds of potential strategies to stop the body’s attack. But, this work could reveal new ways to attack cancer.

Sources: HHMI, Science

About the Author
  • Experienced research scientist and technical expert with authorships on over 30 peer-reviewed publications, traveler to over 70 countries, published photographer and internationally-exhibited painter, volunteer trained in disaster-response, CPR and DV counseling.
You May Also Like
JUL 21, 2021
Genetics & Genomics
Researchers Detect DNA in Air Samples
JUL 21, 2021
Researchers Detect DNA in Air Samples
Scientists have shown that it's possible to assess what organisms might be living in a particular habitat by collecting ...
AUG 04, 2021
Genetics & Genomics
Variants May Predict Which Young People Are at Risk for Severe COVID-19
AUG 04, 2021
Variants May Predict Which Young People Are at Risk for Severe COVID-19
While people carry mostly the same genes, there are many small changes in the sequences of those genes, and small variat ...
SEP 17, 2021
Genetics & Genomics
Ancient Humans Rarely Chose Cousins as Mates
SEP 17, 2021
Ancient Humans Rarely Chose Cousins as Mates
Ancient families that lived together were unlikely to have mated with one another, new research has suggested. Scientist ...
SEP 30, 2021
Microbiology
Malaria Parasite Seems to be Evolving to Evade Diagnostic Tests
SEP 30, 2021
Malaria Parasite Seems to be Evolving to Evade Diagnostic Tests
When health officials are trying to control a disease outbreak, diagnostic tests can be a crucial tool that provides inf ...
OCT 14, 2021
Microbiology
Leprosy Has Been Detected in Wild Chimpanzees for the First Time
OCT 14, 2021
Leprosy Has Been Detected in Wild Chimpanzees for the First Time
Leprosy has been infecting people since ancient times, and is estimated to have caused about 202,000 new infections in 2 ...
OCT 15, 2021
Genetics & Genomics
Genes Seem to Significantly Impact the Results We Get From Exercise
OCT 15, 2021
Genes Seem to Significantly Impact the Results We Get From Exercise
Individual health is shaped by many different factors, including the sequences and expression levels of genes, the makeu ...
Loading Comments...