Abstract A30: Alisertib acts synergistically with sonidegib by modulating primary cilia assembly in a pediatric RELA ependymoma cell line
Bibliographic record
Abstract
Abstract Introduction: Recently we found that RELA ependymomas (EPN) demonstrate inappropriate activation of the Hedgehog (Hh) pathway. However, how this activation is modulated remains to be investigated. Primary cilia are essential to positive and negative modulation of Hh signaling and changes in ciliation seem to be linked to Hh drug resistance in pediatric cancers. In contrast, targeting cilia integrity by molecules that prevents ciliary disassembly, such as Aurora-A (AURKA), has been shown to overcome this resistance. However, the role of the Hh pathway and the prevalence and function of cilia in pediatric RELA ependymoma (EPN) subgroup have not been examined. Thus, we explored the effect of Hh inhibitor, sonidegib, alone or in combination with Alisertib, AURKA inhibitor, in EPN RELA cell line. Methods: Hh pathway activation of RELA cell line (BXD-1425) was evaluated by immunostaining using ARL13B, a marker specific for ciliary membranes, proto-oncogene Smoothened (SMO) and Hh effector, GLI, antibodies in untreated cells or after stimulation with SMO agonist (SAG). Western blot was performed for protein expression of GLI1, GLI2, and full-length (FL) and repressor form (R) of Hh transcriptional program GLI3. Cell proliferation was assessed by CCK8 assay. Cell apoptosis was detected with Annexin V-FITC by flow cytometry. Results: We showed that EPN RELA cell line is frequently ciliated. Fluorescence intensity showed SMO and GLI recruitment to cilia in both BXD untreated cells and after stimulation with SAG, implicating in activation of Hh signals. Surprisingly, sonidegib treatment reduced ciliary formation in BXD cell line. Cilia loss was followed by increase of GLI recruitment to cilia and GLI2 expression, potentially by reduction of GLI3R. Our results indicate that impaired GLI processing probably by cilia disruption could explain persistent activation of downstream Hh pathway. To test this hypothesis, we targeted the cilia integrity through the combination of sonidegib with alisertib, to see if the cilia maintenance might affect Hh function and overcome sonidegib resistance. The combination prevented the primary cilia disruption followed by upregulation of GLI3R and downregulation of GLI recruitment to cilia, GLI2, and GLI3FL expression. Our data point towards to a synergistic combination that enhances sonidegib efficiency by primary cilia preservation, reducing cell proliferation and increasing apoptosis BXD cells compared to drugs alone treatment. Conclusion: Our findings suggest a synergistic combination of sonidegib with alisertib that enhances the inhibition of Hh major effectors such as GLIs (GLI2 and GLI3FL) and induces GLI3R expression. Our data suggest that combination of these agents may represent a novel approach for treatment of ST-EPN-RELA tumors to overcome chemoresistance and these mechanisms are potentially mediated by primary cilia, a key regulator for Hh activity. Citation Format: Taciani de Almeida Magalhães, Gustavo Alencastro Veiga Cruzeiro, Kleiton Silva Borges, Cherry Liu Yulu, Graziella Ribeiro de Souza, Keteryne Rodrigues da Silva, Carlos Alberto Scridelli, Adrian Salic, Luiz Gonzaga Tone. Alisertib acts synergistically with sonidegib by modulating primary cilia assembly in a pediatric RELA ependymoma cell line [abstract]. In: Proceedings of the AACR Special Conference on the Advances in Pediatric Cancer Research; 2019 Sep 17-20; Montreal, QC, Canada. Philadelphia (PA): AACR; Cancer Res 2020;80(14 Suppl):Abstract nr A30.
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How this classification was reachedexpand
Full frame distilled prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. Learned from the 10,348 direct Codex labels and 10,348 direct Gemma labels. Candidate is the union of thresholded teacher heads; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels or direct frontier model labels.
Codex and Gemma teacher scores by category
| Category | Codex | Gemma |
|---|---|---|
| Metaresearch | 0.001 | 0.001 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.000 |
| Bibliometrics | 0.000 | 0.000 |
| Science and technology studies | 0.000 | 0.000 |
| Scholarly communication | 0.000 | 0.000 |
| Open science | 0.000 | 0.000 |
| Research integrity | 0.000 | 0.001 |
| Insufficient payload (model declined to judge) | 0.000 | 0.000 |
Machine scores (provisional)
The two teacher heads of the student model, read on this work. A score orders the frame for review; it never asserts a category, and the validation status ships verbatim with every row.
Baseline scores from an immature model (maturity gate not passed, 7 training rounds). Scores rank; they never assert a category.
score_only:v0-immature-baseline · verbatim from the scoring run: score_only means the number may rank works, and no category label ships from itClassification
machine, unvalidatedMachine predicted; a candidate call from one teacher head, not a consensus.
How this classification was reached, model by model and score by score, is at the end of the page under "How this classification was reached".