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Updated: Dec 8, 2025
A Method for Screening and Validation of Resistant Mutations Against Kinase Inhibitors
Published on: December 7, 2014
CRISPR/Cas9 genome-wide loss-of-function screening identifies druggable cellular factors involved in sunitinib
Peter Makhov1, Ji A Sohn2, Ilya G Serebriiskii3,4
1Molecular Therapeutics Program, Fox Chase Cancer Center, Philadelphia, PA, USA. Petr.Makhov@fccc.edu.
Background:
Multi-targeted tyrosine kinase inhibitors (TKIs) are the standard of care for patients with advanced clear cell renal cell carcinoma (ccRCC). However, a significant number of ccRCC patients are primarily refractory to targeted therapeutics, showing neither disease stabilisation nor clinical benefits.
Methods:
We used CRISPR/Cas9-based high-throughput loss of function (LOF) screening to identify cellular factors involved in the resistance to sunitinib. Next, we validated druggable molecular factors that are synthetically lethal with sunitinib treatment using cell and animal models of ccRCC.
Results:
Our screening identified farnesyltransferase among the top hits contributing to sunitinib resistance in ccRCC. Combined treatment with farnesyltransferase inhibitor lonafarnib potently augmented the anti-tumour efficacy of sunitinib both in vitro and in vivo.
Conclusion:
CRISPR/Cas9 LOF screening presents a promising approach to identify and target cellular factors involved in the resistance to anti-cancer therapeutics.
Insights
Researchers identified farnesyltransferase as a key factor in clear cell renal cell carcinoma (ccRCC) resistance to sunitinib. Inhibiting this enzyme with lonafarnib enhanced sunitinib
Area of Science:
- Oncology
- Molecular Biology
- Drug Discovery
Background:
- Multi-targeted tyrosine kinase inhibitors (TKIs) are standard treatment for advanced clear cell renal cell carcinoma (ccRCC).
- A significant portion of ccRCC patients exhibit primary resistance to TKIs, experiencing no disease stabilization or clinical benefit.
Purpose of the Study:
- To identify cellular factors contributing to sunitinib resistance in ccRCC using a high-throughput screening approach.
- To validate druggable molecular targets that are synthetically lethal with sunitinib in ccRCC models.
Main Methods:
- Employed CRISPR/Cas9-based high-throughput loss-of-function (LOF) screening to identify resistance factors.
- Validated identified targets using in vitro and in vivo ccRCC cell and animal models.
Main Results:
- Farnesyltransferase was identified as a major factor in sunitinib resistance in ccRCC.
- Combined treatment with lonafarnib (a farnesyltransferase inhibitor) and sunitinib demonstrated potent anti-tumour efficacy in vitro and in vivo.
Conclusions:
- CRISPR/Cas9 LOF screening is a valuable method for discovering and targeting cellular factors involved in therapeutic resistance.
- Targeting farnesyltransferase represents a potential strategy to overcome sunitinib resistance in ccRCC.
