Promising discovery in the treatment of cancer
Scientists from the University of Pennsylvania and Penn’s Abramson Cancer Center showed that immune cells modified by CRISPR-Cas9 the so-called “genetic scissors” have a sustained effect on fighting cancer in the body.
The modification of immune cells with the CRISPR-Cas9 technique, the so-called “genetic scissors”, gives new hope in cancer treatment. According to research published in Science, T cells whose DNA was modified by CRISPR survived in the body and continued to attack tumors 9 months after injection. Until now, other techniques of genetic manipulation of immune cells have only been effective as a cancer weapon for less than a week.
What is this new approach?
One way to fight cancer is to extract T cells (white blood cells that attack abnormal cells growing in the body) from the patient and amplify their effect through genetic manipulation before they are reinjected into the patient. These altered cells then become stronger and can prove effective against cancer cells.
Longer-acting than CAR-T cells
This technique is used for CAR T cells, T lymphocytes, which are genetically engineered to recognize cancer antigens that are only present on the surface of cancer cells. The T lymphocytes, which have become CAR-T cells, then play their role and destroy the diseased cells by binding to their target cells. The limit of these CAR T cells is the risk that, depending on the dose or size of the target tumor, they will act against other cells in the body and trigger a dangerous immune chain reaction for patients already weakened by the disease.
The method used enables the modified immune cells to achieve a much more balanced effect against cancer, is based on another technique for manipulating T cells – the CRISPR-Cas9 system. These “genetic scissors” edited the DNA of T-cells in three areas: The first two “edits” of their DNA allow natural receptors on these cells to be replaced by more efficient ones, while the third removes the T-cell receptor that would allow cancer cells to counteract their immune response. T cells modified by CRISP-R Cas9, therefore, have a stronger weapon against cancer cells and an “armor” to protect them from a counter-attack. “This is the first confirmation of the ability of CRISPR-Cas9 technology to address multiple genes simultaneously in humans and illustrates the potential of this technology to treat many diseases that were previously incurable,” said Carl June, lead author of the study.
Demonstrating treatment safety
This new cancer arsenal has been tested in a clinical trial on three patients aged 60 years with advanced cancer, two with myeloma and one with sarcoma. The first lesson was that none of them experienced any side effects of this new treatment. Although there was no improvement in their cancers, the condition of two patients definitely stabilized. However, the condition of the third patient continued to deteriorate. Still, their work has made it possible to ensure the safety of the treatment and its feasibility in humans, which is a prerequisite for other studies on the effectiveness of CRISPR-Cas9 in modifying T lymphocytes in various types of more or less advanced cancers.