New research from the Keck School of Medicine of USC has uncovered alarming similarities in the DNA changes observed in young adults who vape and those who smoke traditional cigarettes. The study, published in the American Journal of Respiratory Cell and Molecular Biology, provides the most comprehensive analysis to date of how vaping affects DNA methylation across the entire genome.
Summary: A comprehensive genome-wide study reveals that young adults who vape show DNA methylation changes similar to smokers, potentially increasing their risk of developing diseases including cancer.
Estimated reading time: 6 minutes
DNA Methylation: A Key to Understanding Health Risks
The research team, led by Stella Tommasi, PhD, an associate professor of research population and public health sciences at the Keck School of Medicine, examined DNA methylation in oral cells of young adult vapers, smokers, and non-users. DNA methylation is a chemical modification that can effectively turn genes “on” or “off” and is crucial for normal cellular processes. However, when disrupted, it can lead to the development of various diseases, including cancer.
Using a state-of-the-art genetic sequencing technique called whole genome bisulfite sequencing, the researchers analyzed over 25 million sites across the genome. This approach provided a much more comprehensive view compared to previous studies, which typically examined only 2-3% of genetic regions in vapers or smokers.
“Our findings indicate that the changes in DNA methylation observed in vapers may contribute to the development of disease, including cancer,” said Tommasi. She added, “Electronic cigarettes are not as safe as some people claim that they are, even if the level of most toxicants and carcinogens present in e-liquid and vapor is generally much lower than that found in cigarette smoke.”
Key Findings and Implications
The study included 30 young adults with an average age of 23.5 years, divided equally into three groups: vapers, smokers, and non-users. After accounting for potential confounding factors, the researchers found:
- 831 differentially methylated regions (DMRs) in vapers and 2,863 in smokers.
- 346 DMRs (46% of all DMR-associated genes in vapers) overlapped between vapers and smokers.
- The most significant shared DMR was located within HIC1, a tumor-suppressor gene linked to various cancers, including those associated with tobacco use.
These shared methylation patterns were found on gene sites known to regulate important biological signaling pathways that drive disease development. This suggests that DNA methylation in vapers, much like in smokers, can contribute to the development of diseases such as cancer.
Tommasi emphasized the significance of the HIC1 finding: “This is an exciting discovery because the methylation of this gene has never before been identified in vapers.”
Unique Impacts of Vaping
Importantly, the study also revealed that more than half of the DMRs found in vapers were not detected in smokers. This finding aligns with the fact that e-cigarettes produce a wide range of harmful or potentially harmful chemicals, some of which are not found in traditional cigarettes.
Future Research and Public Health Implications
The research team is now examining a larger group of participants to learn more about how different aspects of vaping, such as flavors and additives, as well as the duration and intensity of use, impact DNA methylation. Their goal is to establish a molecular signature for vaping that can be used to assess associated health risks in the general population.
“These findings have significant implications for public health and tobacco regulation that aim to keep vaping products away from young people, who are a particularly vulnerable population,” Tommasi stated.
Questions and Concerns
This study raises several important questions:
- How do the long-term health effects of vaping compare to smoking?
- Are certain types of e-cigarettes or vaping liquids more harmful than others?
- How can public health policies be adapted to address the risks associated with vaping, especially among young adults?
As research in this field progresses, it will be crucial to continue monitoring the health impacts of vaping and to develop effective strategies for preventing youth uptake of these products.
Quiz
- How many differentially methylated regions (DMRs) were found in vapers?
- What percentage of DMR-associated genes in vapers overlapped with smokers?
- What is the name of the tumor-suppressor gene identified as the most significant shared DMR between vapers and smokers?
Answer Key:
- 831
- 46%
- HIC1 (Hypermethylated In Cancer 1)
Further Reading:
- CDC: E-cigarette use among youth and young adults: https://www.cdc.gov/tobacco/e-cigarettes/youth.html
- NIH: Vaping devices (electronic cigarettes) DrugFacts: https://nida.nih.gov/publications/drugfacts/vaping-devices-electronic-cigarettes
- WHO: Tobacco: E-cigarettes: https://www.who.int/news-room/questions-and-answers/item/tobacco-e-cigarettes
Glossary of Terms:
- DNA Methylation: A process by which methyl groups are added to DNA molecules, potentially changing gene activity.
- Epigenetics: The study of changes in gene expression that do not involve changes to the underlying DNA sequence.
- Differentially Methylated Regions (DMRs): Areas of DNA with different methylation patterns between groups or conditions.
- Whole Genome Bisulfite Sequencing: A technique used to determine DNA methylation patterns across the entire genome.
- Tumor-Suppressor Gene: A gene that helps control cell growth and prevent cancer.
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