Immunotherapy, chosen in 2013 by the journal Science as one of the scientific breakthroughs of the year, is a novel treatment used to combat certain tumors. In essence, it consists of strengthening our body’s natural defenses, such as T lymphocytes, a type of white blood cell, so that they can locate and destroy cancer cells .
However, in an essay published in The Lancet , this strategy has several drawbacks. On the one hand, patients often experience different side effects that are often complicated. Furthermore, it is not easy to determine whether the procedure is being effective – if it is not, the cancer could spread through the body or even become more resistant – and, in addition, it has been observed that, in some variants of this technique, immunotherapy it does not represent a benefit in the medium term for 80% of the patients treated with it. In fact, there are those affected who do not even react.
Now, a team of researchers from the National Cancer Institute (INC), in the USA, coordinated by Nicholas P. Restifo, an expert in immunology from this institution, has presented in the journal Nature the conclusions of a large study in the More than one hundred genes are identified that intervene in the mechanism that facilitates the elimination of tumors through the use of the aforementioned T lymphocytes . To do this, they used a gene editing technology called CRISPR that has allowed them to consecutively “turn off” certain genes in cells of melanoma , a variety of skin cancer. Then, they examined the effectiveness of T leukocytes.
Restifo and his collaborators examined the genetic profiles of 11,000 individuals collected in the Cancer Genome Atlas, an initiative that aims to list the molecular changes that intervene in the appearance of this disease, and were able to verify that, indeed, the genes identified are related with cytolysis of cancer cells, the process by which they break down , and consequently with a positive response to immunotherapy.
“The results show that many genes play a key role in the success of this cancer treatment, far more than we expected at first,” says Shashank Patel, one of the INC Biomedical Sciences experts who has participated in this work.
The researchers hope that this breakthrough will shed some light on one of the issues that many oncologists worry about: the resistance of tumors to treatments based on the use of T lymphocytes. In a statement, Restifo said that if genes described in his study are finally validated in clinical trials, significant progress will be made in this regard.
“If we finally understand the mechanisms involved in resistance to immunotherapy, we will be able to develop new tactics to combat the disease,” he says. “In fact, in the future, this finding could accelerate the development of drugs that prevent tumor cells from using their escape mechanisms and thus help patients experience a completely satisfactory response,” says Restifo.
Reference: Shashank J. Patel, Neville E. Sanjana, et al. Identification of essential genes for cancer immunotherapy. Nature (2017). DOI: 10.1038 / nature23477.
Image: Jonathan Bailey / NHGRI
