An enzyme that helps mop up the products of cellular oxidation might also serve as a powerful biomarker for pleural mesothelioma. People with the lowest levels of this enzyme survived longer with mesothelioma than those with higher levels.
Glutathione peroxidase-1 (GPX-1) is an enzyme found in all cells. It helps keep toxins from building up inside cells. It also helps regulate certain cellular processes.
But there is also evidence that GPX-1 may play a role in the development of cancer. Researchers in Egypt recently discovered that pleural mesothelioma tumors have more GPX-1 than the healthy tissue around them. The less they have, the better the prognosis.
The findings suggest that GPX-1 could be a useful biomarker for pleural mesothelioma.
Mesothelioma Diagnosis and Prognosis
Pleural mesothelioma is a cancer in the tissue surrounding the lungs. Survival is historically dismal. One reason is that it is difficult to diagnose mesothelioma. By the time most people know they have it, it may be too late for effective treatment.
Having a reliable biomarker for pleural mesothelioma could change those odds. A biomarker is something in the cells, tissue, or body fluid of someone with an illness that is either not found in healthy people or is found at a different level.
If doctors know that mesothelioma patients produce more or less of a particular substance, mesothelioma diagnosis can be easier, faster, and more reliable.
A biomarker for pleural mesothelioma can also help with prognosis. If levels of a certain substance go up or down in relation to the death of cancer cells, doctors can measure that substance to gauge how well a treatment works.
GPX-1 as a Biomarker for Pleural Mesothelioma
All cells contain some amount of GPX-1. It is an antioxidant enzyme. Hydrogen peroxide is one product of cellular oxidation. It influences some cellular processes. But it is also toxic at high levels. GPX-1 turns hydrogen peroxide into harmless water.
Previous studies show GPX-1 may play a role in cancer development. Researchers at Egypt’s Zagazig University Hospital checked GPX-1 levels in mesothelioma cells and patients. The goal was to see whether it could be helpful as a biomarker for pleural mesothelioma.
In the lab, researchers discovered that mesothelioma cells had higher GPX-1 levels than the surrounding pleural tissue. “It was found to be of important diagnostic specificity in the differentiation of MPM from normal tissues,” reports researcher Amal Gharib.
They also assessed GPX-1 as a potential biomarker in pleural mesothelioma patients. They included 98 Zagazig Hospital mesothelioma surgery patients in the analysis. Patients with the lowest GPX-1 levels lived twice as long as those with high expression.
“Median overall survival was about 16 months in patients with high GPX1 expression levels, while it was found to be about 40 months in low GPX1 levels,” states the report in the Swiss medical journal, Diagnostics.
Some of the other potential biomarkers for pleural mesothelioma include:
- BRCA1-associated protein a (BAP1) loss
- methylthioadenosine (MTAP)
- 5-hydroxymethylcitosine (5-hmC)
- glucose transporter 1 (GLUT1)
- insulin like-growth factor II messenger RNA-binding protein 3 (IMP3)
- enhanced zeste homologue 2 (EZH2) staining
- cyclin-dependent kinase inhibitor 2A (CDKN2A) homozygous deletion (HD) testing
- soluble mesothelin
- microRNA quantification
Combining biomarkers can improve the accuracy of testing for mesothelioma.
Gharib, A, et al, “Assessment of Glutathione Peroxidase-1 (GPX1) Gene Expression as a Specific Diagnostic and Prognostic Biomarker in Malignant Pleural Mesothelioma”, December 7, 2021, Diagnostics, Volume 11, Issue 12, https://www.mdpi.com/2075-4418/11/12/2285