A single injection shot may lower the risk of heart attacks by 40 percent to 90 percent in humans; however, testing is currently done only on mice for now.

Scientists at the Harvard Stem Cell Institute (HSCI) are working with researchers from the University of Pennsylvania to develop a "genome-editing" approach, which can reduce cholesterol levels permanently and hence reduce the risk of heart attacks.

Kiran Musunuru of HSCI is leading the research and says that the study is focusing on how to alter the function of PCSK9, a liver gene. Previous research has shown that PCSK9 is a cholesterol regulator, accountable for high cholesterol in humans and heart attacks.  

Musunuru says that PCSK9 gene is present mainly in the liver, which makes a protein that is active in the bloodstream. The protein averts cholesterol removal from the blood. A few drug companies are developing antibodies; however, antibody-based drugs do not last forever and patients will need to take drugs on a regular basis. Musunuru also highlighted that statin drugs can also be used to reduce cholesterol levels but many people who take the drug on a daily basis have had heart attacks.

"What we were thinking was that, with this genome-editing technology, we can do something we couldn't do before: make permanent changes in the genome at the level of the DNA. We can actually go to the source. So the question was whether we can use genome editing to make normal people like people born with the 'good' mutations," says Musunuru.

The scientists say that their experiments on mice have shown positive results. The findings of the study reveal that the approach followed by the researchers reduces the cholesterol levels in mice by around 35 percent to 40 percent. If the finding is translated to humans, then risk of heart attacks can be reduced by up to 90 percent.

The researchers say that many people worldwide die of heart attacks every year. Heart attack is responsible for the deaths of many elderly people, as well as people aged over 40 years. If a single shot targets the liver and changes the genome responsible for heart attack, then it can also be taken as a vaccination in the future. A one-time treatment may permanently alter cholesterol levels in humans and reduce the occurrence of heart attacks.

Musunuru pointed out that it can take another decade of research before the new approach finds its way to testing and trials on human beings.