YAP1 Knockdown and Panobinostat Treatment Increase Apoptotic Response and Decrease Gene Expression in Ewing Sarcoma Cells

Authors

• Luna Collazo-Garcia, St Marys UniversityFollow
• Alejandra Favela Santos, St Marys UniversityFollow
• Madeline Torres-Salazar, St Marys UniversityFollow
• Isabella Toscano, St Marys UniversityFollow
• Terry Jo Shackleford, St Marys UniversityFollow

Files

Publication Date

Spring 5-10-2026

Keywords

Ewing Sarcoma, Pediatric Cancer, YAP1, Panobinostat, Apoptosis, Proliferation, Migration, qRTPCR, Incucyte, Tissue Culture

Description

Ewing sarcoma (EWS) is considered to be one of the most aggressive pediatric malignancies, often characterized by its dysregulated gene expression driven by oncogenic fusion proteins. The Hippo signaling effector Yes-associated protein 1 (YAP1) has been known in promoting cell proliferation, survival, and therapeutic resistance in multiple cancers. However, its role in Ewing sarcoma response to treatment remains unclear. This study investigated whether YAP1 knockdown enhances the sensitivity of Ewing sarcoma cells to the histone deacetylase inhibitor Panobinostat. Ewing sarcoma, ES8, cells were transfected with a YAP1-targeting siRNA (siYAP1) or a non-targeting control (siControl) and treated with DMSO, 0.1 μM, or 1.0 μM Panobinostat. Cell proliferation and apoptosis were monitored over time using the Incucyte S3 Live-Cell Analysis System. Apoptosis was assessed through caspase 3/7 activity, and YAP1 gene expression was quantified using qRT-PCR. Panobinostat treatment resulted in a dose-dependent decrease in cell proliferation and increase in apoptotic activity. While YAP1 knockdown alone reduced proliferation and modestly increased apoptosis compared to controls. qRT-PCR confirmed a significant reduction in YAP1 expression following siRNA treatment. However, the combined effect of YAP1 knockdown and Panobinostat did not produce a strong increase in apoptosis beyond drug treatment alone.These findings suggest that while YAP1 contributes to Ewing sarcoma cell growth and survival, Panobinostat is the primary driver of apoptosis under these conditions. Thus, further studies are needed to determine whether YAP1 plays a context-dependent role in therapeutic sensitivity.

Collection

Cell and Molecular Methods

Format

pdf

Size or Duration

14 Pages

City

San Antonio

Creative Commons License

This work is licensed under a Creative Commons Attribution-NonCommercial-No Derivative Works 4.0 International License.

Recommended Citation

Collazo-Garcia, Luna; Santos, Alejandra Favela; Torres-Salazar, Madeline; Toscano, Isabella; and Shackleford, Terry Jo, "YAP1 Knockdown and Panobinostat Treatment Increase Apoptotic Response and Decrease Gene Expression in Ewing Sarcoma Cells" (2026). Cell and Molecular Methods. 10.
https://commons.stmarytx.edu/biostulab25/10