Identification of Potential Core Genes Associated With Air Pollution Exposure‑Related Acute Myeloid Leukemia Via Integrated Network Toxicology and Molecular Docking Analysis

The air we breathe is a complex mixture of gases and tiny particles, some natural and some created by human industry. While we often think of air pollution as a threat to our lungs or heart, a growing body of evidence suggests it may also reach deep into the blood-making factories of our bodies. Inside the bone marrow, stem cells constantly divide and mature to become the red blood cells, white blood cells, and platelets that keep us alive. When this delicate process is disrupted, it can lead to blood cancers, including acute myeloid leukemia, a fast-moving disease where immature white blood cells crowd out healthy ones. For decades, scientists have known that certain chemicals, like benzene found in gasoline and industrial solvents, can trigger this disease. However, the exact molecular steps that turn a breath of polluted air into a cellular disaster remain largely a mystery. Understanding these hidden pathways is crucial, not just for treating the disease, but for preventing it by identifying which specific pollutants are the most dangerous and how they interact with our biology.

A team of researchers from Lanzhou University in China has taken a fresh approach to solving this puzzle, using powerful computer tools to map the invisible connections between air pollution and leukemia. Instead of testing chemicals on cells in a lab dish, they built a digital model of the human body's response to nine common air pollutants: benzene, toluene, formaldehyde, sulfur dioxide, carbon monoxide, nitrogen dioxide, nitric oxide, ozone, and naphthalene. They started by gathering data on the genes these pollutants are known to affect, and separately, they collected a list of genes involved in acute myeloid leukemia. By finding the genes that appeared on both lists, the researchers identified 157 specific targets where the pollution and the disease overlap. This intersection represents the precise points where environmental toxins might be hijacking the body's normal functions to cause cancer.

To make sense of this large group of genes, the scientists constructed a complex network, similar to a map of social connections, to see which genes talked to each other most frequently. In this digital web, some genes acted as major hubs, connecting to many others. The researchers used advanced algorithms to zoom in on the most important hubs, eventually narrowing their focus down to a core group of five genes that seemed most critical to the disease process. These genes, named CASP9, HDAC1, CASP3, EGFR, and AR, are involved in controlling cell death, regulating how genes are turned on or off, and managing cell growth. The team then cross-referenced these five genes with clinical data from thousands of leukemia patients to see if their activity levels predicted how long a patient would survive. The results were striking: the activity of these five genes was strongly linked to patient outcomes. For instance, higher levels of CASP9 and HDAC1 were associated with longer survival times, while lower levels of CASP3, EGFR, and AR correlated with better outcomes, suggesting these genes play a decisive role in the disease's progression.

The study did not stop at identifying these genes; it also simulated how the pollutants themselves might physically attach to them. Using molecular docking, a technique that predicts how well two molecules fit together like a key in a lock, the researchers tested the binding strength between the five key genes and the nine pollutants. The simulations revealed that these pollutants could indeed latch onto the genes with significant stability. One pollutant, naphthalene, showed a particularly strong grip on the CASP9 gene, while toluene also demonstrated a firm connection to both CASP9 and the AR gene. These findings suggest that the pollutants do not just cause general damage but may directly interfere with the specific proteins that control cell life and death. The researchers noted that while their work provides a strong theoretical framework and points to specific biological targets, it remains a computer-based prediction. The next step would be to verify these interactions in living organisms and human patients. Nevertheless, this study offers a clear, data-driven roadmap for understanding how the air we breathe might be influencing the development of leukemia, highlighting specific genes that could serve as early warning signs or targets for future therapies.