Abstract P3-06-10: Temozolomide & vorinostat as a targeted therapy strategy for triple negative breast cancer
Notice bibliographique
Résumé
Abstract Approximately 15% of newly diagnosed breast cancers (BC) are classified as triple negative (TNBC), which have a worse prognosis than hormonal receptor-positive BCs. Standard treatment for TNBC includes cytotoxic chemotherapies that are associated with significant toxicities. Currently the only targeted therapy (PARP inhibition) exists for the 10% of TNBC patients who have germline BRCA mutations. There is an ongoing unmet need for TNBC that may include targeted strategies to improve outcomes. The alkylating agent temozolomide (TMZ) is an oral chemotherapy drug used in the treatment of glioblastomas. The therapeutic benefit of TMZ largely depends on cells not being able to fully repair the DNA damage it causes. O6-methylguanine-DNA methyltransferase (MGMT) is normally expressed and able to repair damage caused by TMZ; however, MGMT is often silenced by promoter methylation in many tumours (mMGMT), and such tumours show a better response to TMZ than those with unmethylated promoters (uMGMT). MGMT has been shown to be methylated in up to 50% of TNBC, suggesting TMZ may be a targeted treatment option. Additionally, studies in other tumour sites suggest that adding an HDAC inhibitor (HDACi) to TMZ can increase response and early phase trials have shown this combination is well tolerated. We have previously shown cytotoxicity with TMZ in mMGMT TNBC cell lines and now hypothesize that the addition of HDAC inhibition to TMZ will have synergistic effects. Using in vitro models, we explored the efficacy of Vorinostat (HDACi) alone and in combination with TMZ and/or cisplatin utilizing TNBC cell lines: HTB132 (uMGMT) and HTB26 (mMGMT). Cytotoxicity assays were utilized to determine median effective dose (EC50) for each treatment and then we performed EC50 synergy testing. Percent viability was calculated as the absorbance ratio of treated/untreated cells X 100. The EC50 was then determined by calculating the intercept of the log effect vs log RV dose. We found that Cisplatin and HDAC inhibition showed similar cytotoxicities in both cell lines. The addition of cisplatin to either TMZ or HDACi increased cytotoxicity compared to either treatment alone in the mMGMT cell line HTB26; however, the addition of cisplatin to TMZ in the uMGMT cell line showed the greatest cytotoxicity. Interestingly, we also saw an increase in cytotoxicity when cells were treated with the combination TMZ and HDACi, regardless of methylation status of the MGMT promotor. Finally, the triple combination therapy did not increase cytotoxicity. Although HDAC inhibition showed cytotoxicity regardless of methylation status of the MGMT promotor; it was increased by the combination with TMZ in both cell lines evaluated. Further, the addition of cisplatin to TMZ did not improve cytotoxicity in the mMGMT cell line but did increase cytotoxicity in the uMGMT cell line. There appears to be no benefit to triple therapy in either cell line. We are currently evaluating these combinations in a xenograft murine model to provide pre-clinical support for a Phase II funded clinical trial in TNBC patients. Citation Format: Elizabeth N Kornaga, Ailian Yang, Kathy Gratton, Zhong Qiao Shi, Nancy A Nixon, Gloria Roldan Urgoiti, Don G Morris. Temozolomide & vorinostat as a targeted therapy strategy for triple negative breast cancer [abstract]. In: Proceedings of the 2019 San Antonio Breast Cancer Symposium; 2019 Dec 10-14; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2020;80(4 Suppl):Abstract nr P3-06-10.
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 | 0,000 |
| 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 | 0,001 |
| Charge utile insuffisante (le modèle a refusé de juger) | 0,011 | 0,003 |
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 ».