Proprietary AML Cell Lines: Best-in-Class Models for High-Throughput Drug Screening and Target Validation

This invention comprises a set of proprietary cell lines that model aggressive Acute Myeloid Leukemia (AML) by expressing constitutively active forms of the myeloid Src-family kinases, Fgr and Hck. These novel lines serve as highly predictive and sensitive tools for drug discovery, allowing researchers to quickly screen compounds, identify therapeutic vulnerabilities, and validate drug targets against a critical oncogenic pathway in AML.

Description

The core of this invention is the engineered TF-1 cell line variants, which have been transformed by the expression of CC-Hck or CC-Fgr (Src-family kinases fused to a coiled-coil domain). This fusion forces the kinases into a state of constitutive, oncogenic activation, replicating a critical mechanism found in high-risk AML. This transformation is validated by the cells' ability to grow independent of normal cytokine signals (GM-CSF-independent phenotype) and their enhanced proliferation in vivo, resulting in significant tumor burden. Crucially, the engineered cell lines exhibit an acquired, extreme dependency on the active kinase for survival. This dependency makes them up to 1,000-fold more sensitive to Src-family kinase inhibitors compared to their non-transformed counterparts. This hypersensitivity makes these models superior to standard AML cell lines for identifying and testing inhibitors, providing a uniquely powerful and high-fidelity screening platform. Furthermore, the cell lines link the active kinases to specific downstream pathways (mTORC1-S6K and Fak), making them ideal for testing combination therapy strategies that target the entire signaling axis to overcome resistance.

Applications

- High-Throughput Screening (HTS): Used by pharmaceutical and biotechnology companies to screen chemical libraries for novel or potent inhibitors of activated Fgr and Hck.
- Target Validation: Employed to validate the efficacy of new or existing drug candidates that target Fgr, Hck, and their downstream signaling partners (mTORC1/S6K and Fak) in AML.
- Drug Resistance Studies: Utilized to develop and test strategies to prevent or overcome acquired drug resistance in AML treatment.
- Companion Diagnostic Development: Serving as a reliable, consistent biological standard for developing and calibrating assays that detect the relevant activated kinase targets in patient samples.

Advantages

- Superior Screening Sensitivity: Exhibit over a 1,000-fold increase in sensitivity to Src-family kinase inhibitors, providing a clear and unparalleled therapeutic window for drug testing.
- Biologically Relevant Model: The cell lines accurately reflect a high-risk oncogenic mechanism in AML (constitutive Fgr/Hck activation), offering better translational relevance than many standard models.
- Ideal for Combination Therapy: Mechanistically link the target kinases to mTORC1-S6K and Fak pathways, making them perfect tools to screen synergistic combination drugs for preventing acquired resistance.
- Robust Phenotype: Demonstrate a clear, measurable cytokine-independent growth phenotype that is easily quantifiable for high-throughput screening applications.
- Preclinical Predictiveness: Proven to form aggressive tumors in vivo in mouse xenograft models, validating their utility for in vivo preclinical studies and efficacy testing.

Invention Readiness

The engineered cell lines are fully established and functionally validated, with robust in vitro and in vivo data generated. Specifically, data shows that the lines successfully mimic aggressive AML by exhibiting cytokine-independent growth and dramatically enhanced sensitivity to Src-family kinase inhibitors (nanomolar IC50). Furthermore, proteomic data has been generated to precisely define the activated downstream pathways (mTORC1/S6K and Fak). These cell lines are ready for immediate use as a screening platform. Further studies needed include utilizing the cell lines to directly test and confirm the superior efficacy of the proposed combination therapy approach in vivo and optimizing their scale-up for industrial high-throughput screening.

IP Status

Research Tool

Related Publication(s)

Shu, S. T., Chen, L., Gonzalez-Areizaga, G., & Smithgall, T. E. (2025). Constitutive activation of the Src-family kinases Fgr and Hck enhances the tumor burden of acute myeloid leukemia cells in immunocompromised mice. Scientific Reports, 15(1). https://doi.org/10.1038/s41598-024-83740-6