Researchers find a factor which predicts long survival in patients with brain tumor
The glioma, a tumor born in glial cells -neuron auxiliaries-, shows a survival rate which, in the 85 % of patients, does not last more than two years. Now, a research study led by the UB professor Manel Esteller, director of the Josep Carreras Leukaemia Research Institute and ICREA researcher, discovered an epigenetic loss which enables the identification of the 15 % resting glioma cases in which the survival lasts longer. The article has been published in the journal Acta Neuropathologica.
The glioma, a tumor born in glial cells -neuron auxiliaries-, shows a survival rate which, in the 85 % of patients, does not last more than two years. Now, a research study led by the UB professor Manel Esteller, director of the Josep Carreras Leukaemia Research Institute and ICREA researcher, discovered an epigenetic loss which enables the identification of the 15 % resting glioma cases in which the survival lasts longer. The article has been published in the journal Acta Neuropathologica.
“We started this study looking for genes with regulating functions of the genome expression which lost their activity in cancer. We identified one specifically -named NSUN5- on which we did not have much knowledge”, notes Esteller. At first, the most remarkable thing was to state that the alteration of the gene was almost exclusive for brain tumors.
According to the expert, they did research on the gene in laboratory cells and experimental models, but when they analysed the impact on patients with glioma they realized the importance of what they had found: “The NSUN5 epigenetic loss predicted independently this minor percentage of patients who would have a longer survival on other biomarkers”.
Esteller notes the results are shocking because most of the times they find factors that show tumors to develop negatively. From a mechanical perspective, it seems that, by evolutionary selection, a brain tumor soon to disappear ends up creating the alteration of NSUN5, which seems to be stuck in time. This is why this cancer develops does not develop much and survival lasts longer.
The microenvironment factors surrounding the glioma, such as a lack of oxygen and local nutrients, contribute to induce this inactivation of NSUN5, which allows the tumor not to die but to grow only a bit so that the patient shows a good prognostic. “Therefore, -notes Esteller-, we now have a marker that predicts this 15 % of cases with a good clinical course, but it would be exceptional to turn the other 85 % cases of patients in which, “touching” the NSUN5 gene, into a longer survival too”.“We do not know how to do this yet, but it should be carefully studied”, concludes the director of the Josep Carreras Leukaemia Research Institute.
Article reference:
Janin, M.; Ortiz-Barahona, V., et al. "Epigenetic loss of RNA methyltransferase NSUN5 in glioma targets ribosomes to drive a stress adaptive translational program". Acta Neuropathologica, August 2019. Doi: 10.1007/s00401-019-02062-4