Related Experiment Video
Updated: Dec 29, 2025
In Vivo Model for Testing Effect of Hypoxia on Tumor Metastasis
Published on: December 9, 2016
Development of an Ewing sarcoma cell line with resistance to EWS‑FLI1 inhibitor YK‑4‑279
Erin Conn1, Sarah Hour1, David Allegakoen1
1Department of Oncology, Georgetown University Medical Center, Georgetown University, Washington, DC 20057, USA.
Abstract:
Despite Ewing sarcoma (ES) being the second most common pediatric malignancy of bone and soft tissue, few novel therapeutic approaches have been introduced over the past few decades. ES contains a pathognomonic chromosomal translocation that leads to a fusion protein between EWSR1 and an ets family member, most often FLI1. EWS‑FLI1 is the most common type of fusion protein and is a well‑vetted therapeutic target. A small molecule inhibitor of EWS‑FLI1, YK‑4‑279 (YK) was developed with the intention to serve as a targeted therapy option for patients with ES. The present study investigated resistance mechanisms by developing an ES cell line specifically resistant to YK. The ES cell line A4573 was treated with YK to create resistant cells by long term continuous exposure. The results revealed that resistance in A4573 was robust and sustainable, with a >27‑fold increase in IC50 lasting up to 16 weeks in the absence of the compound. Resistant ES cells were still sensitive to standard of care drugs, including doxorubicin, vincristine and etoposide, which may be valuable in future combination treatments in the clinic. Resistant ES cells revealed an increased expression of CD99. RNA sequencing and qPCR validation of resistant ES cells confirmed an increased expression of ANO1, BRSK2 and IGSF21, and a reduced expression of COL24A1, PRSS23 and RAB38 genes. A functional association between these genes and mechanism of resistance remains to be investigated. The present study created a cell line to investigate YK resistance.
Insights
Researchers developed a Ewing sarcoma cell line resistant to the targeted therapy YK-4-279. This resistant cell line, showing increased CD99 expression, remains sensitive to standard chemotherapy, offering insights into targeted therapy resistance mechanisms.
Area of Science:
- Oncology
- Molecular Biology
- Pharmacology
Background:
- Ewing sarcoma (ES) is a rare pediatric bone and soft tissue cancer with limited therapeutic advancements.
- The EWS-FLI1 fusion protein, resulting from a common chromosomal translocation, is a key therapeutic target in ES.
- YK-4-279 (YK) is a small molecule inhibitor targeting the EWS-FLI1 fusion protein, offering a potential targeted therapy for ES.
Purpose of the Study:
- To investigate the mechanisms of resistance to the EWS-FLI1 inhibitor YK-4-279 in Ewing sarcoma.
- To develop and characterize a YK-4-279 resistant Ewing sarcoma cell line for further study.
Main Methods:
- Generation of a YK-4-279 resistant ES cell line (A4573) through long-term continuous exposure.
- Assessment of drug resistance by measuring IC50 values and sensitivity to standard chemotherapy agents (doxorubicin, vincristine, etoposide).
- Analysis of gene expression changes in resistant cells using RNA sequencing and qPCR, focusing on CD99, ANO1, BRSK2, IGSF21, COL24A1, PRSS23, and RAB38.
Main Results:
- A robust and sustainable YK-4-279 resistance was established in the A4573 cell line, with a >27-fold increase in IC50.
- Resistant cells maintained sensitivity to standard ES chemotherapies, suggesting potential for combination treatments.
- Increased expression of CD99, ANO1, BRSK2, and IGSF21, alongside decreased expression of COL24A1, PRSS23, and RAB38, was observed in resistant cells.
Conclusions:
- A YK-4-279 resistant Ewing sarcoma cell line was successfully created, providing a valuable model for studying resistance mechanisms.
- The observed resistance profile highlights potential therapeutic strategies involving combination treatments with existing chemotherapies.
- Further investigation is warranted to elucidate the functional roles of identified genes in YK-4-279 resistance.
More Related Videos
09:38Establishment and Characterization of Three Afatinib-resistant Lung Adenocarcinoma PC-9 Cell Lines Developed with Increasing Doses of Afatinib
Published on: June 26, 2019
09:58Mapping the Structure-Function Relationships of Disordered Oncogenic Transcription Factors Using Transcriptomic Analysis
Published on: June 27, 2020