CRISPR Gene Editing Newsletter
Issue #4September 29, 20257 studies

CRISPR protein beats mRNA for cystic fibrosis repair, while gene editing restores hearing in deaf mice

CRISPR protein beats mRNA for cystic fibrosis repair, while gene editing restores hearing in deaf mice

Monday, September 29th CRISPR Gene Editing Newsletter Issue #4

This week brought major advances in gene editing therapies, with researchers making progress on everything from cystic fibrosis to hearing loss. The standout finding? Sometimes the simpler approach works better.

🎯 CRISPR Protein Outperforms mRNA for Cystic Fibrosis Treatment

When it comes to delivering gene editing tools to treat cystic fibrosis, researchers discovered that packaging the actual Cas9 protein works better than sending genetic instructions (mRNA) to make the protein inside cells.

  • Scientists tested both approaches using lipid nanoparticles (tiny fat bubbles that deliver cargo to cells) to fix mutations in the CFTR gene that causes cystic fibrosis

  • The protein version significantly outperformed the mRNA version for both lung editing and restoring function of the CFTR protein that's broken in cystic fibrosis patients

  • This finding could reshape how researchers design gene therapies, since mRNA approaches (like COVID vaccines) have gotten most of the attention lately

Why this matters: Cystic fibrosis affects about 30,000 Americans, and current treatments only manage symptoms rather than fix the underlying genetic cause. This research suggests a more direct protein-based approach might be the key to developing an actual cure.

🥉 Top 5% journal 🔗 Nano Letters 🗓️ Sep 17

Key Findings

🔊 Gene Editing Restores Hearing in Deaf Mice

Researchers used a custom-designed gene editor called SchABE8e to fix a mutation causing hereditary deafness in mice. The treatment achieved up to 48.5% editing efficiency and resulted in near-complete hearing recovery that lasted at least four months. The mice had a condition mimicking DFNA15, a form of inherited deafness in humans.

💡 Gene editing could offer permanent hearing restoration for genetic deafness, not just hearing aids or implants.
🥈 Top 2% journal 🔗 Nature Communications 🗓️ Sep 18

🧬 New Imaging Technique Maps Gene Editing Success in Living Tissue

Scientists developed a way to see exactly where gene editing worked using in situ sequencing - essentially reading DNA changes while looking at tissue under a microscope. They tested this in mouse brains and livers, plus macaque livers, and found that repeated doses of gene editing treatments didn't interfere with each other's effectiveness.

💡 We can now see precisely where gene therapies work in the body, making them safer and more predictable.
🥇 Top 1% journal 🔗 Nature Biomedical Engineering 🗓️ Sep 19

🩸 Mystery of VEXAS Anemia Finally Solved

VEXAS syndrome causes severe anemia, and researchers figured out why: the genetic mutation kills off red blood cell precursors during early development, but mature red blood cells are actually normal. They found that cells with the mutation die off due to problems with protein disposal (ubiquitylation) and ribosome construction, similar to Diamond-Blackfan anemia.

💡 VEXAS anemia is like having a faulty assembly line - the problem isn't the final product, but the manufacturing process.
🥇 Top 1% journal 🔗 Blood 🗓️ Sep 19

🧠 Brain Tumors Hijack Immune Cells Using Lactate

Brain tumors create low-oxygen environments that produce lactate, which transforms nearby immune cells (macrophages) into tumor-helping SPP1+ cells. These reprogrammed immune cells then promote tumor growth and block cancer-fighting T cells. Targeting this process with stiripentol enhanced anti-PD-1 immunotherapy effectiveness.

💡 Brain tumors turn the immune system against itself, but we can potentially reverse this metabolic hijacking.
🥇 Top 1% journal 🔗 Neuro-Oncology 🗓️ Sep 19

🔬 Monkeys Develop Human-Like Brain Degeneration

Scientists created the first primate model of ataxia-telangiectasia (A-T) using CRISPR in rhesus macaques. Unlike mouse models, these monkeys developed the severe brain degeneration seen in human patients, including cerebellar atrophy and loss of Purkinje cells that control movement. Single-cell analysis revealed which brain cell types are most affected.

💡 Primate models can capture human brain diseases that mouse models miss, opening new paths for treatment development.
🥈 Top 2% journal 🔗 Cell Reports Medicine 🗓️ Sep 17

💡 Metabolism Predicts CAR-T Cell Success

Researchers used label-free optical imaging to monitor CAR-T cell metabolism throughout manufacturing. They discovered that metabolic measurements can predict which cells will be most effective against tumors and identified optimal conditions for gene transfer using both viral and CRISPR methods.

💡 Checking cellular metabolism during manufacturing could make CAR-T therapies more effective and consistent.
🥇 Top 1% journal 🔗 Nature Biomedical Engineering 🗓️ Sep 16

Implications

This week's research shows gene editing is moving from proof-of-concept to practical medicine, with major advances in delivery methods, quality control, and disease modeling. The shift toward protein-based delivery and metabolic monitoring suggests the field is maturing beyond just making edits to making them work reliably in patients.

Studies in this issue

Primary sources used for this newsletter.

  1. Cas9 Protein Works Better Than mRNA for Lipid Nanoparticle Delivery in Fixing CFTR
    main storyNano letters2025-09-17PMID 40961329
  2. Metabolic imaging tracks the health of engineered immune cells
    key findingNature biomedical engineering2025-09-16PMID 40958004
  3. Mapping gene editing locations directly in mouse and macaque tissues
    key findingNature biomedical engineering2025-09-19PMID 40973816
  4. Lack of ATM protein causes varied symptoms and movement cell loss in a monkey model of ataxia-telangiectasia
    key findingCell reports. Medicine2025-09-17PMID 40961921
  5. Improved gene editing restores hearing in a mouse model of inherited deafness
    key findingNature communications2025-09-18PMID 40968144
  6. VEXAS anemia involves a mixed loss of red blood cell precursors
    key findingBlood2025-09-19PMID 40971475
  7. Lactate-Driven SPP1+ Immune Cells May Promote Growth of Low-Oxygen Adapted Brain Tumor Cells
    key findingNeuro-oncology2025-09-19PMID 40973181

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