Abstract 2740: Identification of new binding partners of the DNA repair protein MGMT using a proteomic discovery-based approach in glioblastoma
Notice bibliographique
Résumé
Abstract Background: Glioblastoma multiforme (GBM) is characterized by aberrant angiogenesis and widespread invasion through the brain parenchyma. The DNA repair protein O6-methylguanine-DNA methyltransferase (MGMT) has been extensively characterized for its role in resistance to alkylating agents used in treatment of GBM. Our team discovered an inverse relationship between expression of MGMT and GBM angiogenesis and invasion. To gain new insights into how MGMT affects angiogenesis and invasion, we used a proteomic-based approach integrated with bioinformatics analysis to identify potential MGMT-binding partners (BPs) for the first time in GBM. Methods: We used T98G, a human GBM cell line with constitutive expression of MGMT and performed direct immunoprecipitation (IP) of endogenous MGMT using an anti-MGMT antibody or the isotype control. Following elution of the antibody, proteins were resolved by SDS-PAGE, stained, excised from the gel then subjected to trypsin digestion and identified by liquid chromatography-tandem mass spectrometry using the LTQ-Orbitrap Elite mass analyzer. The resulting tryptic peptides were purified and identified by LC-tandem mass spectrometry (MS/MS). The resultant MS/MS spectra were searched against a proteome database for peptide matching and protein identification. Proteins identified with high confidence (Scaffold software) were used to construct the biological network of MGMT-BPs in GBM using the Build Network tool provided by MetaCore. Results: We identified a total of 186 MGMT-BPs, which were not identified in the elution from the isotype control. Using gene ontology (GO) database, we determined the function and biological role of identified proteins (mitochondrial metabolism, DNA repair and replication, ubiquitin pathway, transcription regulators, RNA post-transcriptional processing, transcriptional splicing, protein biosynthesis and trafficking, cellular metabolism, cell cycle and division, response to stress and cell death, cell migration and invasion). The list of new BPs was uploaded to MetaCore and the most relevant biological process was enriched based on public GO databases. Among the top proteins identified with a very high confidence, we found newly identified MGMT-BPs, which may underlie the role of MGMT in angiogenesis and invasion, namely the splicing factor heterogeneous nuclear ribonucleoprotein A1 (hnRNPA1), known for its role in the packaging of pre-mRNA into hnRNP particles and alternative splicing of angiogenic factors (VEGF-A and the fibroblast growth factor 2) and annexin A2. Knockdown of annexin A2 decreased invasion, angiogenesis and proliferation in vivo. Conclusion: Our study provides new mechanistic insights into how MGMT affects angiogenesis and invasion in GBM, which may ultimately lead to the identification of new therapeutic targets to improve the poor outcome of this devastating disease. Note: This abstract was not presented at the meeting. Citation Format: Siham Sabri, Yaoxian Xu, Bassam Abdulkarim. Identification of new binding partners of the DNA repair protein MGMT using a proteomic discovery-based approach in glioblastoma. [abstract]. In: Proceedings of the 105th Annual Meeting of the American Association for Cancer Research; 2014 Apr 5-9; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2014;74(19 Suppl):Abstract nr 2740. doi:10.1158/1538-7445.AM2014-2740
Récupéré en direct depuis OpenAlex et désinversé. Les résumés ne sont pas conservés dans cette base de données : les index inversés représentent 8,6 Go des 9,3 Go de texte de la base, et le serveur dispose de 13 Go libres.
Comment cette classification a été obtenuedéplier
Prédiction machine sur la base complète
Imitation des enseignantsNi prévalence calibrée, ni vérité terrain. Validation humaine à venir. Le volet Gemma est une étiquette directe du modèle pour chaque travail de la base, lue sur la notice réduite au titre. Le volet Codex est un classifieur appris des 10 348 étiquettes directes de Codex et calibré sur les taux pondérés de l'échantillon; les champs sans appui suffisant ne portent aucun appel Codex. Le mode candidate est l'union des deux volets; le consensus est leur intersection. Ces sorties portent le statut machine_predicted_unvalidated et ne sont pas des étiquettes humaines.
Scores du classifieur distillé par catégorie (deux têtes)
| Catégorie | Codex | Gemma |
|---|---|---|
| Métarecherche | 0,000 | 0,000 |
| Méta-épidémiologie (sens strict) | 0,000 | 0,000 |
| Méta-épidémiologie (sens large) | 0,000 | 0,001 |
| Bibliométrie | 0,001 | 0,001 |
| Études des sciences et des technologies | 0,000 | 0,000 |
| Communication savante | 0,000 | 0,000 |
| Science ouverte | 0,000 | 0,000 |
| Intégrité de la recherche | 0,000 | 0,000 |
| Charge utile insuffisante (le modèle a refusé de juger) | 0,001 | 0,001 |
Scores machine (provisoires)
Les deux têtes enseignantes du modèle étudiant, lues sur ce travail. Un score ordonne la base pour la relecture; il n'affirme jamais une catégorie, et le statut de validation accompagne chaque rangée tel quel.
Scores de référence d'un modèle non mature (critères de maturité non atteints, 7 itérations). Un score ordonne; il n'affirme jamais une catégorie.
score_only:v0-immature-baseline · tel quel depuis la passe de notation : score_only signifie que le nombre peut ordonner les travaux, et qu'aucune étiquette de catégorie n'en découleClassification
machine, non validéePrédiction automatique; un appel candidat d’une seule source (Gemma direct ou Codex distillé), pas un consensus.
Le détail, modèle par modèle et score par score, se trouve en fin de page sous « Comment cette classification a été obtenue ».