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Published on: March 27, 2020
Induction of stable drug resistance in human breast cancer cells using a combinatorial zinc finger transcription
Jeongeun Lee1, Andrew S Hirsh, Ben S Wittner
1Molecular Pathology Unit, Massachusetts General Hospital, Charlestown, Massachusetts, United States of America.
Abstract:
Combinatorial libraries of artificial zinc-finger transcription factors (ZF-TFs) provide a robust tool for inducing and understanding various functional components of the cancer phenotype. Herein, we utilized combinatorial ZF-TF library technology to better understand how breast cancer cells acquire resistance to fulvestrant, a clinically important anti-endocrine therapeutic agent. From a diverse collection of nearly 400,000 different ZF-TFs, we isolated six ZF-TF library members capable of inducing stable, long-term anti-endocrine drug-resistance in two independent estrogen receptor-positive breast cancer cell lines. Comparative gene expression profile analysis of the six different ZF-TF-transduced breast cancer cell lines revealed five distinct clusters of differentially expressed genes. One cluster was shared among all 6 ZF-TF-transduced cell lines and therefore constituted a common fulvestrant-resistant gene expression signature. Pathway enrichment-analysis of this common fulvestrant resistant signature also revealed significant overlap with gene sets associated with an estrogen receptor-negative-like state and with gene sets associated with drug resistance to different classes of breast cancer anti-endocrine therapeutic agents. Enrichment-analysis of the four remaining unique gene clusters revealed overlap with myb-regulated genes. Finally, we also demonstrated that the common fulvestrant-resistant signature is associated with poor prognosis by interrogating five independent, publicly available human breast cancer gene expression datasets. Our results demonstrate that artificial ZF-TF libraries can be used successfully to induce stable drug-resistance in human cancer cell lines and to identify a gene expression signature that is associated with a clinically relevant drug-resistance phenotype.
Insights
Artificial zinc-finger transcription factors (ZF-TFs) can induce drug resistance in breast cancer cells. This study identified a common gene signature associated with fulvestrant resistance and poor prognosis.
Area of Science:
- Cancer biology
- Molecular oncology
- Drug resistance mechanisms
Background:
- Fulvestrant is a key anti-endocrine therapy for estrogen receptor-positive breast cancer.
- Acquisition of drug resistance limits the long-term efficacy of fulvestrant treatment.
- Understanding resistance mechanisms is crucial for developing improved therapeutic strategies.
Purpose of the Study:
- To investigate the mechanisms of fulvestrant resistance in breast cancer using artificial zinc-finger transcription factor (ZF-TF) libraries.
- To identify a gene expression signature associated with acquired fulvestrant resistance.
- To explore the clinical relevance of the identified resistance signature.
Main Methods:
- Utilized a combinatorial library of nearly 400,000 artificial ZF-TFs to induce drug resistance in breast cancer cell lines.
- Performed comparative gene expression profiling on ZF-TF-transduced cells.
- Conducted pathway enrichment analysis on differentially expressed genes.
- Interrogated public human breast cancer datasets to assess the prognostic value of the resistance signature.
Main Results:
- Isolated six ZF-TF library members that induced stable, long-term fulvestrant resistance in breast cancer cells.
- Identified a common gene expression signature shared across all resistant cell lines.
- This signature overlapped with estrogen receptor-negative states and resistance to other anti-endocrine agents.
- Unique gene clusters were associated with myb-regulated genes.
- The common resistance signature was linked to poor prognosis in independent patient datasets.
Conclusions:
- Artificial ZF-TF libraries are effective tools for inducing and studying stable drug resistance in cancer cell lines.
- A novel gene expression signature associated with fulvestrant resistance and poor clinical outcome was identified.
- This signature provides insights into resistance mechanisms and potential therapeutic targets in breast cancer.
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