Thanks to revolutionary advancements in CRISPR technology, medical specialists are on the brink of transforming the treatment and prevention of genetic disorders and diseases. CRISPR (Clustered Regularly Interspaced Short Palindromic Repeats) is a Nobel Prize-winning gene-editing tool that allows scientists to cut and modify DNA with unprecedented precision. By using the Cas9 enzyme, CRISPR can activate or deactivate genes and even insert new DNA to correct genetic abnormalities, revolutionizing our ability to address previously untreatable conditions.

Now, researchers from the USC Alfred E. Mann Department of Biomedical Engineering have taken CRISPR to the next level by incorporating focused ultrasound. This new tool enables precise targeting of CRISPR’s gene-editing abilities to specific areas of the body, significantly improving its efficiency and accuracy. The team is currently exploring how this technology can enhance cancer immunotherapy.

“CRISPR is revolutionary,” said Peter Yingxiao Wang, Dwight C. and Hildagarde E. Baum Chair in Biomedical Engineering. “You can edit the genome or epigenome directly in the cell nucleus, potentially treating genetically related diseases. But we’re pushing it further by making it controllable. Now, instead of continuously editing the genome, we can activate it at a specific location and time using a non-invasive, remote-controlled ultrasound wave. That’s the breakthrough.”

Wang’s lab has already made significant strides in cancer immunotherapy by using engineered Chimeric Antigen Receptor (CAR) T-cells—immune cells enhanced to target cancer more effectively. By utilizing focused ultrasound waves, the team can precisely control these CAR T-cells, directing them to target tumor cells while sparing healthy tissue. Their recent study shows the promising potential of combining ultrasound with CRISPR technology, demonstrating how this synergy can successfully target and eliminate cancer cells in mouse models.

“This is the first study that provides a comprehensive, ultrasound-controllable CRISPR toolbox to knock out, activate, or silence specific genes,” said Longwei Liu, Assistant Professor of Biomedical Engineering. “When combined with immunotherapy, we showed enhanced tumor treatment in mice.”

One of the significant challenges with traditional CRISPR technology is its continuous gene-editing activity once it’s introduced into the body. “Continuous expression of CRISPR can cause immunogenicity—meaning the body could recognize the Cas9 protein and attack the cells,” Liu explained. “This can trigger unwanted immune responses. With our controllable system, we can flip the CRISPR activity on and off, offering another layer of precision.”

The team’s breakthrough utilizes focused ultrasound to induce localized temperature changes at specific sites, activating CRISPR at precise locations where it’s needed. For example, they can target tumors and alter the DNA of cancer cells to make them more vulnerable to CAR T-cell-based immunotherapy.

“The ultrasound wave connects through the temperature change to the CRISPR molecule,” Wang said. “When we turn it on, the CRISPR molecule activates at the targeted site. After a set time, it naturally decays, shutting down until it’s needed again.”

In their cancer-fighting research, the team used ultrasound-guided CRISPR to target telomeres—the protective DNA-protein structures at the ends of chromosomes that help maintain chromosome integrity and limit cell division. By cutting these telomeres, CRISPR can trigger the cell to break down and die, preventing cancer cells from repairing themselves.

“The telomere has many repeats, and we use CRISPR, guided by ultrasound, to cut it,” Wang explained. “This leads to the chromosome being cut at both ends, causing the tumor cell to lose its ability to repair. The cell will then undergo apoptosis and die.”

Furthermore, the team’s approach enhances the immune response by introducing SynNotch CAR T-cells—engineered to target cancer cells expressing CD19, a protein activated by the CRISPR tool. This ensures that only cancerous cells are targeted, minimizing damage to healthy tissue.

“After training on the tumor surface, these SynNotch CAR T-cells will produce a receptor on their surface to target the entire population of the tumor,” Wang said. “With these three factors—focused ultrasound, CRISPR gene editing, and SynNotch CAR T-cells—we achieve highly efficient tumor eradication.”

Promising laboratory results have shown that the combination of ultrasound-guided CRISPR and CAR T-cell technology has a profound effect on cancer cells in mice. “The results were surprisingly good,” Wang said. “In all the mice, the tumor not only slowed its growth but also completely disappeared. These are very encouraging results.”

With these groundbreaking developments, this new ultrasound-enabled CRISPR system holds the potential to revolutionize the treatment of genetic disorders and cancers, offering a highly controlled, targeted, and precise method for gene therapy and immunotherapy. This innovation is a major step toward more effective and personalized treatments in modern medicine.

By Impact Lab