Scientists are developing new therapies that target the epigenome, a set of chemical markers that regulate gene activity, as a means to treat or prevent diseases without altering the underlying DNA sequence. This emerging approach, known as epigenome editing, focuses on modifying how genes are expressed rather than rewriting the genetic code itself.
Unlike the fixed genome inherited from parents, the epigenome is dynamic and responds to environmental factors such as diet, stress, infections, and exposure to toxins. These influences can change gene expression patterns, potentially increasing the risk of conditions like asthma, cardiovascular disease, and cancer. By adjusting the epigenome, researchers hope to reverse harmful effects accumulated over a person’s lifetime.
At the forefront of this field is Tune Therapeutics, which is conducting clinical trials of an epigenome-editing therapy for chronic hepatitis B. The treatment aims to silence viral DNA within liver cells, thereby restoring the immune system’s ability to clear the infection. Early data released in May showed that higher doses of the drug significantly reduced markers of hepatitis B in some trial participants.
More than a dozen companies are working on epigenome-editing technologies, pursuing applications beyond infectious diseases. For example, therapies might dial down gene activity in cases where complete gene knockout would be too risky, as in chronic pain management. This fine-tuning approach contrasts with conventional gene editing methods like CRISPR, which physically cut DNA and are currently reserved for severe genetic disorders due to potential safety concerns.
Researchers also envision treatments that could provide long-lasting benefits through single interventions rather than ongoing medication. One such example is a potential therapy from Scribe Therapeutics designed to silence a liver gene that impairs cholesterol clearance, potentially reducing the need for daily statins and lowering heart disease risk.
The possibility of reversible and targeted gene regulation has prompted discussion about non-medical uses of epigenome editing. Scientists have speculated about enhancing traits such as height or cognitive ability, and even temporary boosts in natural hormone levels for athletic performance. However, experts emphasize that the technology remains in its early stages and that the immediate focus should be on medical applications.
Ethicists note that while epigenome editing introduces new technical capabilities, the concept of influencing gene expression through environment and behavior is longstanding. As Hank Greely, a Stanford law professor specializing in biotechnology ethics, remarked, humans have been modifying the effects of nurture in various ways for generations. The current advance lies in directly manipulating the molecular mechanisms underlying these changes.
As clinical trials progress, key considerations will include the safety, efficacy, and equitable access to these potentially transformative therapies. Researchers and ethicists alike are cautiously optimistic that epigenome editing could open new avenues for disease treatment while raising important questions about the future use of genetic technologies.