MicroRNA192-5p demethylation inhibits glucose metabolism and angiogenesis in non-small cell lung cancer by targeting EREG/PI3K/AKT

Lung cancer remains one of the most formidable challenges in modern medicine, particularly a form known as non-small cell lung cancer. While new treatments have extended lives, the five-year survival rate for all stages of the disease remains stubbornly low. To improve these odds, scientists are looking beyond the tumor itself and examining how cancer cells feed themselves. Cancer cells are voracious eaters; they consume far more sugar than healthy cells and process it in a way that generates acid and builds new blood vessels to feed the growing mass. This metabolic switch is a hallmark of the disease. At the same time, the body uses tiny, natural regulators called microRNAs to control which genes are turned on or off. Sometimes, in cancer, these regulators are silenced or lost, allowing the tumor to grow unchecked. Understanding how these tiny molecules interact with the cancer's fuel supply could reveal new ways to starve the disease.

Researchers at Harbin Medical University Cancer Hospital and its affiliated hospital set out to investigate one specific regulator, a molecule called miR-192-5p, and its relationship with sugar metabolism in lung cancer. They began by examining tissue samples from six patients who had undergone surgery for non-small cell lung cancer. By staining the tissue and looking under a microscope, they confirmed the familiar chaotic structure of the cancer cells compared to the orderly arrangement of healthy lung tissue nearby. When they measured the proteins responsible for moving sugar into cells and breaking it down, they found a clear pattern: the cancer tissues were packed with high levels of these sugar-processing proteins, while the healthy tissues had much less. At the same time, the level of miR-192-5p was significantly lower in the cancer samples. This suggested that the loss of this tiny regulator might be allowing the cancer to ramp up its sugar consumption.

To test this idea, the team moved to the laboratory, working with human lung cancer cells grown in a dish. They artificially increased the amount of miR-192-5p in these cells and watched what happened. The result was immediate and clear: the levels of the sugar-processing proteins dropped. The cells could no longer process sugar as aggressively as before. The researchers then explored how this change affected the tumor's ability to build new blood vessels, a process essential for tumor growth. They placed the treated lung cancer cells next to human blood vessel cells. In normal conditions, the lung cancer cells would encourage the blood vessel cells to multiply and form new networks. However, when the lung cancer cells were boosted with miR-192-5p, they lost this ability. The blood vessel cells stopped multiplying and failed to form the intricate tube-like structures needed to supply a tumor.

The scientists also wanted to know if they could naturally restore miR-192-5p levels using a chemical that removes chemical tags from DNA, a process known as demethylation. They treated the lung cancer cells with a drug called 5-aza-CdR, which is known to strip these tags away. This treatment successfully increased the levels of miR-192-5p in the cells. Just like when they artificially added the molecule, this natural boost led to a decrease in the sugar-processing proteins and a reduction in the ability of nearby blood vessel cells to grow and migrate. This confirmed that the chemical state of the DNA controlling miR-192-5p is a critical switch for the cancer's metabolism.

To understand exactly how miR-192-5p exerts this control, the team traced the molecular pathway. They identified a specific protein called EREG as a direct target of miR-192-5p. When miR-192-5p is present, it binds to the instructions for making EREG and stops it from being produced. Normally, EREG acts as a signal that turns on a major internal pathway known as PI3K/AKT, which in turn tells the cell to grab more sugar and process it. By blocking EREG, miR-192-5p effectively cuts the signal, shutting down the pathway that drives the cancer's hunger. The researchers verified this by showing that when miR-192-5p levels were high, the activity of the PI3K/AKT pathway dropped significantly.

The study concludes that miR-192-5p acts as a brake on the aggressive sugar metabolism that fuels non-small cell lung cancer. When this brake is released due to DNA changes, the cancer accelerates its growth and blood vessel formation. By using demethylation to restore miR-192-5p, it is possible to re-engage this brake, reducing the cancer's ability to feed itself and spread. This work suggests that targeting the DNA mechanisms that control miR-192-5p could offer a new strategy to disrupt the energy supply of lung cancer, potentially improving outcomes for patients.