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Updated: Jul 23, 2025
Studying Triple Negative Breast Cancer Using Orthotopic Breast Cancer Model
Published on: March 20, 2020
MCAK Inhibitors Induce Aneuploidy in Triple-Negative Breast Cancer Models
John C Smith1, Stefan Husted2, Jay Pilrose3
1Medical Sciences, Indiana School of Medicine-Bloomington, Bloomington, IN 47405, USA.
Abstract:
Standard of care for triple-negative breast cancer (TNBC) involves the use of microtubule poisons such as paclitaxel, which are proposed to work by inducing lethal levels of aneuploidy in tumor cells. While these drugs are initially effective in treating cancer, dose-limiting peripheral neuropathies are common. Unfortunately, patients often relapse with drug-resistant tumors. Identifying agents against targets that limit aneuploidy may be a valuable approach for therapeutic development. One potential target is the microtubule depolymerizing kinesin, MCAK, which limits aneuploidy by regulating microtubule dynamics during mitosis. Using publicly available datasets, we found that MCAK is upregulated in triple-negative breast cancer and is associated with poorer prognoses. Knockdown of MCAK in tumor-derived cell lines caused a two- to five-fold reduction in the IC50 for paclitaxel, without affecting normal cells. Using FRET and image-based assays, we screened compounds from the ChemBridge 50 k library and discovered three putative MCAK inhibitors. These compounds reproduced the aneuploidy-inducing phenotype of MCAK loss, reduced clonogenic survival of TNBC cells regardless of taxane-resistance, and the most potent of the three, C4, sensitized TNBC cells to paclitaxel. Collectively, our work shows promise that MCAK may serve as both a biomarker of prognosis and as a therapeutic target.
Insights
Targeting MCAK, a protein that limits aneuploidy, shows promise for treating triple-negative breast cancer (TNBC). Inhibiting MCAK sensitizes TNBC cells to paclitaxel and may serve as a prognostic biomarker.
Area of Science:
- Oncology
- Molecular Biology
- Genetics
Background:
- Standard treatment for triple-negative breast cancer (TNBC) uses paclitaxel, a microtubule poison that induces aneuploidy.
- While initially effective, paclitaxel treatment often leads to dose-limiting peripheral neuropathies and the development of drug-resistant tumors.
- Identifying novel therapeutic targets is crucial for overcoming resistance and improving TNBC treatment outcomes.
Purpose of the Study:
- To investigate the role of the microtubule depolymerizing kinesin, MCAK, as a potential therapeutic target in TNBC.
- To determine if MCAK inhibition can sensitize TNBC cells to paclitaxel and overcome drug resistance.
- To evaluate MCAK as a prognostic biomarker in TNBC.
Main Methods:
- Analysis of publicly available datasets to assess MCAK expression and its correlation with prognosis in TNBC.
- In vitro knockdown of MCAK in TNBC cell lines to evaluate its effect on paclitaxel sensitivity.
- High-throughput screening of a compound library to identify MCAK inhibitors using FRET and image-based assays.
Main Results:
- MCAK is upregulated in TNBC and associated with poorer patient prognoses.
- MCAK knockdown significantly reduced paclitaxel IC50 in TNBC cells without affecting normal cells.
- Three novel MCAK inhibitors were identified, which induced aneuploidy, reduced TNBC cell survival, and sensitized cells to paclitaxel.
Conclusions:
- MCAK is a promising therapeutic target for TNBC, potentially overcoming paclitaxel resistance.
- MCAK inhibition represents a viable strategy to enhance the efficacy of existing chemotherapies.
- MCAK may serve as a valuable prognostic biomarker for triple-negative breast cancer.
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