Yale researchers have made a discovery that changes conventional thinking about the role that oxygen plays in the growth of tumors—an area of cancer research that has been intensely studied in recent years.
The results, from the lab of Andre Levchenko, the John C. Malone Professor of Biomedical Engineering, are published in Cell Systems. Other groups collaborating on this study were directed by Chi V. Dang (Johns Hopkins University) and Kshitiz (University of Connecticut).
When tumors start running out of oxygen, they can switch on hypoxia-inducible factor (HIF-1alpha)—a transcription factor, which is a protein that controls the activity of genes. As a result of HIF-1alpha activation, the expression of hundreds of genes can change and dramatically alter the behavior of cancer cells. Although the increase in HIF-1alpha is thought to be steady, the new study led by Levchenko discovered that the levels of this molecule can also repeatedly rise and fall in small groups of cells, particularly in areas of high cell density. The effects of this oscillation are profound, as it allows cancer cells starving for oxygen to resume division and growth. It can also promote pro-cancer genes and inhibit anti-cancer genes… Continue reading.
A UConn School of Dental Medicine researcher used pregnancy to unlock a missing link between various species of mammals and cancer malignancy—fundamentally changing the way we look at cancer metastasis.
Kshitiz, assistant professor in the department of biomedical engineering – a shared department between the School of Dental Medicine, School of Medicine, and School of Engineering – and Gunter Wagner and Andre Levchenko at Yale University used evolutionary biology to draw the connection in the Nature Ecology & Evolution journal.
In many mammals, the placenta invades the wall of the uterus during pregnancy in the same way that cancer cells invade surrounding tissues. In other mammals—including cows, pigs, and horses—the placenta does not invade as aggressively. Interestingly, in these mammals, tumors rarely metastasize or spread… Continue reading.
A new study by researchers at Yale and Johns Hopkins University has discovered how asthmatic bronchial spasms — muscle contractions in the airway that cause difficulty breathing in asthma patients— occur by creating a microdevice that mimics the behavior of the human respiratory airways.
Led by Andre Levchenko, professor of biomedical engineering, and Johns Hopkins postdoctoral fellow Onur Kilic, the team investigated the mechanism by which the smooth muscle surrounding bronchial airways — the network of tubes that deliver oxygen to the lungs — suddenly contract and cause bronchial spasms. During bronchial spasms, sudden contractions of the smooth muscles result in decreased airflow, not only in asthma patients but also in healthy people… Continue reading.
By severely curtailing the effects of antibiotics, the formation of organized communities of bacterial cells known as biofilms can be deadly during surgeries and in urinary tract infections. Yale researchers have just come a lot closer to understanding how these biofilms develop, and potentially how to stop them.
Biofilms form when bacterial cells gather and develop structures that bond them in a gooey substance. This glue can protect the cells from the outside world and allow them to form complex quasi-organisms. Biofilms can be found almost everywhere, including unwashed shower stalls or the surfaces of lakes. Because the protective shell can keep out potential treatments, biofilms are at their most dangerous when they invade human cells or form on sutures and catheters used in surgeries. In American hospitals alone, thousands of deaths are attributed to biofilm-related surgical site infections and urinary tract infections… Continue reading.