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Di Nisio, E.

Publications and source records attributed to Di Nisio, E..

2 recordsLinked to original sources

PatientProfiler: A network-based approach to personalized medicine

Deciphering the intricate mechanisms underlying reprogramming in cancer cells is a crucial challenge in oncology as it holds the key to advance our ability to diagnose and treat cancer patients. For this reason, comprehensive and patient-specific multi-omic characterization of tumor specimens has become increasingly common in clinical practice. While these efforts have advanced our understanding of the molecular mechanisms underlying breast cancer progression, the identification of personalized therapeutic approaches remains a distant goal. The main shortcoming is the absence of a robust computational framework to integrate and interpret the available multi-dimensional data and to drive translational solutions. To fill this gap, we developed PatientProfiler, a computational pipeline that leverages causal interaction data, annotated in our in-house manually-curated resource, SIGNOR, to address how the genetic and molecular background of single patients contributes to the establishment of a malignant phenotype. PatientProfiler is an open-source, R-based package composed of several functions that allows multi-omic data analysis and standardization, generation of patient-specific mechanistic models of signal transduction, and extraction of network-based prognostic biomarkers. To benchmark the tool, we retrieved genomic, transcriptomic, (phospho)proteomic, and clinical data derived from 122 treatment-naive breast cancer biopsies, available at the CPTAC portal. Thanks to this approach, we identified patient-specific mechanistic models (one patient, one network) that recapitulate dysregulated signaling pathways in breast cancer. This collection of models provides valuable insights into the underlying mechanisms of tumorigenesis and disease progression. Moreover, in-depth topological exploration of these networks has allowed us to define seven communities (subnetworks), each associated with a unique transcriptomic signature and a distinct prognostic value. In summary, our work demonstrates that PatientProfiler is a tool for patient-specific network analysis, advancing personalized medicine towards the identification of actionable biomarkers and tailored therapeutic strategies.

systems biology↗

Discovery and characterization of non-canonical E2 conjugating enzymes

E2 conjugating enzymes (E2s) play a central role in the enzymatic cascade that leads to the attachment of ubiquitin to a substrate. This process, termed ubiquitylation is fundamental for maintaining cellular homeostasis and impacts almost all cellular process. By interacting with multiple E3 ligases, E2s direct the ubiquitylation landscape within the cell. Since its discovery, ubiquitylation has been regarded as a post-translational modification that specifically targets lysine side chains (canonical ubiquitylation). We used MALDI-TOF Mass Spectrometry to discover and characterize a family of E2s that are instead able to conjugate ubiquitin to serine and/or threonine. We employed protein modelling and prediction tools to identify the catalytic determinants that these E2s use to interact with ubiquitin as well as their substrates. Our results join a stream of recent literature that challenges the definition of ubiquitylation as an exquisitely lysine-specific modification and provide crucial insights into the missing E2 element responsible for non-canonical ubiquitylation. TeaserE2 conjugating enzymes (E2s) play a fundamental role in the attachment of ubiquitin to its substrate. Most E2s can form an isopeptide bond between the ubiquitin C- terminus and a lysine present on the substrate. We identified a family of E2s, UBE2Q1 and UBE2Q2, able to target amino acids other than lysine. Currently nothing is known about their mechanism of action and what substrates they are targeting, even though genetic ablation of UBE2Q1 produce substantial infertility in mice. Here we answer the question about what the key residues beneath their peculiar activity are. We discovered that UBE2Q1 target the lysine-free cytoplasmic domain of the Golgi resident protein Beta-1,4-galactosyltransferase 1, providing an interesting precedent for the role of non-canonical ubiquitylation in eukaryotic cells.

biochemistry↗