The official MedZine Blog

Also this week MedZine brings you the latest medical news on various medical specialisms. In this editorial two striking studies in oncology are highlighted. The first shows how putting the brake on regulatory T cells boosts anti-tumor immunity. The second describes how sugar helps to find and assess prostate cancer. 

Inhibiting regulatory T cell promotes anti-cancer immune responses

Why doesn't the immune system prevent cancer? This is a central question without an easy answer. It involves a delicate balance between activating and restricting immunity. Liu and colleagues describe a new way to boost the immune response to cancer. The study is published in Nature Medicine. The researchers focused on regulatory T cells (Treg). Under normal conditions, Treg limit autoimmunity, but if the function of these cells is inhibited anti-tumor immunity is enhanced. Inhibiting the enzyme p300 affects the functions of another protein, Foxp3, which plays a key role in the biology of Treg. By deleting the gene for p300, the researchers safely reduced Treg function and limited tumor growth in mice. The same effects could be obtained by using a drug that inhibits p300. The researchers are now trying to translate these findings to the clinical setting.

Using sugar to image prostate cancer

Prostate cancer is the most common form of cancer. Screening for prostate-specific antigen (PSA) levels is increasingly used and allows the identification of prostate cancer at an earlier, and potentially more treatable, stage. Many of these tumors are slow growing and it is difficult to predict which ones are slow growing and which ones are fast growing. In a publication in Science Translational Medicine, Nelson and colleagues describe the first study in humans using hyperpolarized pyruvate to image prostate cancer. The technology uses pyruvate which supplies energy to cells and is created when glucose breaks down in the body. In cancer, pyruvate is often converted to lactate. Previous animal studies have shown that the levels of pyruvate, as it is converted to lactate, can be tracked via magnetic resonance imaging (MRI). The amount of lactate produced and rate of conversion enabled the researchers to precisely detect the limits of a mouse's tumor and identify which cancers were most aggressive. The researchers have shown now in 31 patients that the method is safe in humans and effectively detects tumors in patients with prostate cancer.


Sources: Eurekalert, Nature Medicine and Science Translational Medicine