Abstract For the last twenty-five years an increasing amount of evidence has shown the relevance of epigenetics in cell biology and tissue physiology, being DNA methylation aberrations in cancer the flag-ship for the recognition of its disturbance in human diseases. From the candidate gene approaches, new powerful technologies such as comprehensive DNA methylation microarrays and whole genome bisulfite sequencing has recently emerged that have reinforced the notion of epigenetic disruption in the crossroad of many sickness. From the poster-boy cases of MGMT and GSTP1 hypermethylation in the prediction of alkylating drug response and prostate cancer detection, respectively, to the personalized treatment of leukemia with small molecules targeted to fusion proteins involving histone modifiers such as DOT1L and MLL, the field has walked a long path. The current talk will focus in the epigenetic profiling, basically at the level of DNA methylation and histone modifications, that is starting to provide clinical value in the diagnosis, prognosis and prediction of response to drug therapies, with an emphasis in neoplasia, but without forgetting the novel advances in other human disorders. For cancer, we have already a wide view of the undergoing DNA methylation events that expand beyond classical promoter CpG islands of tumor suppressor genes and we have a growing list of mutated chromatin remodeler genes that contributes to the tumorigenesis process. It is time to apply this knowledge in practical clinical situations like the diagnosis of cancers of unknown primary, the screening of malignancies in high-risk populations or a biomarker selection of the patients that should receive treatment with epigenetic drugs. Citation Format: Manel Esteller, Sr. Cancer epigenomics: From knowledge to applications. [abstract]. In: Proceedings of the Fourth AACR International Conference on Frontiers in Basic Cancer Research; 2015 Oct 23-26; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2016;76(3 Suppl):Abstract nr IA19.
Abstract One of the known hallmarks of cancer is an aberrant RNA transcriptome, and yet, it cannot always be fully due to genetic or epigenetic alterations at the transcriptional start sites of the genes. Indeed, recent evidences point out to new malignant alterations at the RNA level itself. RNA molecules have been found to show more than 100 differently chemically modified nucleotides, and such post-transcriptional modifications play a role in controlling RNA homeostasis, being all grouped under the term ‘epitranscriptome'. In our study, we reported that human glioma cells undergo DNA methylation-associated epigenetic silencing of NSUN5, a candidate 5-methylcytosine RNA methyltransferase. As NSUN5 activity has not been formally described in human cells yet, we studied its potential targets in the human transcriptome, demonstrating its role in the methylation of the cytosine 3782 in the 28S ribosomal RNA (rRNA). Logically, we found that NSUN5 loss generates an unmethylated status at the C3782 position of 28S rRNA, and this depletion drives an overall depletion of protein synthesis under stress conditions, analyzed by O-propargyl-puromycin (OP-Puro) and [3H] leucine incorporation into nascent proteins. However, together with the depletion of global protein synthesis, we observed the emergence of an adaptive translational program for survival under conditions of cellular stress, assessed by combining three NGS-experiments: RNA-seq, Ribo-seq and SILAC. Moreover, as one of the genes increasing its expression upon NSUN5 silencing is the stress-related enzyme NQO1, we found out that NSUN5-depleted gliomas are sensitive to bioactivatable substrates of the NQO1 enzyme. Most importantly, we observed that NSUN5 epigenetic inactivation is a hallmark of glioma patients with long-term survival, conferring it value as a predictor of better patient outcome for this otherwise devastating disease. Citation Format: Vanessa Ortiz Barahona, Maxime Janin, Manel Esteller. Epigenetic loss of NSUN5 in glioma drives a global protein synthesis depletion along with the emergence of a stress adaptive translational program [abstract]. In: Proceedings of the Annual Meeting of the American Association for Cancer Research 2020; 2020 Apr 27-28 and Jun 22-24. Philadelphia (PA): AACR; Cancer Res 2020;80(16 Suppl):Abstract nr 153.
The IDIBELL Cancer Conference (ICC) on Metastasis and Angiogenesis was held in Barcelona, Spain, on May 26-27, 2011. The program content was developed by Dr. Manel Esteller, director of the Cancer Epigenetics and Biology Program (PEBC-IDIBELL), Dr. Oriol Casanovas and Dr. Francesc Viñals Canals of the Catalan Institute of Oncology (ICO-IDIBELL), and Dr. Danny R. Welch from the University of Kansas Cancer Center. The topics discussed during the meeting included the latest advances in epigenetic control of metastasis and tumor cell invasion, and molecular mechanisms of angiogenesis and tumoral angiogenesis, and were presented by invited keynote speakers. One issue that recurred throughout the meeting was the increased appreciation of tumor-stromal/microenvironment interactions and how the tumor cells respond to these signals in the cancer dissemination process.
