Abstract A053 Investigating mechanisms responsible for MAP kinase pathway resistance in RAS-altered neuroblastoma cells
Notice bibliographique
Résumé
Abstract Neuroblastoma (NB) is the most common pediatric solid tumor, responsible for about 15% of childhood cancer-related mortality in the United States. Multiple therapies have been established, which include chemotherapy, radiotherapy, immunotherapy and molecularly-targeted therapy, however resistance to these therapies is the major hinderance in curing NB. RAS pathway mutations are prevalent in relapsed NB and are associated with a poorer overall survival. Therefore, comprehending the mechanisms leading to therapy resistance has become an urgent need. In this study, we attempted to identify the resistance mechanism of NB cell lines towards RAS inhibitors. RAS-altered NB cell lines are treated with trametinib, a MAP kinase pathway inhibitor to perform cell viability assays, immunoblotting and RT PCR. Copy number alteration and translocation studies are performed using spectral karyotyping (SKY) and multiplex interphase fluorescent in-situ hybridization (miFISH). We observed that unlike other RAS-altered NB cell lines (SK-N-AS, CHP-212, LA-N-6, SK-N-BE(2)-C), NB-Eb-C1, which harbors a KRAS G12D mutation shows resistance to both MRTX1133 (KRAS G12D direct inhibitor) and trametinib. Immunoblot against crucial genes regulating NB showed high expression of MYCN, the most relevant biomarker of high-risk neuroblastoma. MYCN is unfortunately undruggable hence, standard treatment for MYCN-amplified neuroblastoma patients does not include targeting MYCN itself. We therefore pursued a hypothesis-driven approach towards identifying possible mechanisms responsible for MYCN driven MEKi-resistance in RAS pathway-altered NB cells. MYCN is known to cross talk with the RAS pathway, however this mechanism is not well understood in NB. Therefore, we performed the clonal assessment of NB cell lines using miFISH and to the best of our knowledge are the first to report that, NB-Eb-C1 has a hypertriploid to hypotetraploid baseline with a low copy-number gain of MYCN. To have a profound understanding of the functionality of MYCN in NB, we have taken 3 different NB cell lines with varied MYCN status. CHP-212 (MYCN amplified-extrachromosomal), SK-N-BE(2)-C (MYCN amplified-homogenously staining region), SK-N-AS (MYCN neutral). SKY and FISH revealed that the MYCN copy-number gain in NBEB cells is the result of a translocation between chromosome 2 and 5 involving MYCN. Of note, another frequently abnormally expressed gene in NB, ALK, is co-translocated with MYCN suggesting potential involvement of both genes in imparting chemoresistance. To understand the mechanism of MYCN overexpression in NBEB we will be performing HiC to check for promoter/enhancer hijacking. Also, to better define this translocation and studying other translocations involved we are performing optical genome mapping using BioNano. Other functional experiments will be performed to look at the impact of the RAS/MAPK alteration on MYCN protein stability. We are confident that this study will contribute towards developing new combinations of targeted therapies to improve outcomes in RAS-altered NB. Citation Format: Subhra Dash, Kerstin Heselmeyer-Haddad, Stacy Stauffer, Lucas Stauffer, Danny Wangsa, Marielli E. Yohe. Investigating mechanisms responsible for MAP kinase pathway resistance in RAS-altered neuroblastoma cells [abstract]. In: Proceedings of the AACR Special Conference in Cancer Research: Advances in Pediatric Cancer Research; 2024 Sep 5-8; Toronto, Ontario, Canada. Philadelphia (PA): AACR; Cancer Res 2024;84(17 Suppl):Abstract nr A053.
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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 | 0,000 |
| Bibliométrie | 0,000 | 0,000 |
| 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) | 0,003 | 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 ».