Generation and Isolation of Cell Cycle-arrested Cells with Complex Karyotypes
April 13th, 2018
Aneuploidy leads to genome instability, which eventually produces cell cycle-arrested cells with complex karyotypes. This paper provides a simple and convenient method to isolate aneuploid cells with complex karyotypes that cease to divide.
The overall goal of this protocol is to provide a simple method to generate and isolate cell cycle-arrested cells with complex karyotypes. This method can provide answers to key questions in the field of aneuploidy research, such as the interaction of the immune system with aneuploid cells. The main advantage of this technique is that it generates a cell population that harbors only complex karyotypes.
To begin the synchronization of RPE-1 hTERT cells, use freshly thawed cells and dispense them into a 10 centimeter tissue culture dish using eight milliliters of standard growth medium. Next, use a hemocytometer to determine the cell number. Then, incubate the cells overnight.
The following day, replace the standard growth medium with medium containing five millimolar thymidine. Incubate for 24 hours at 37 degrees Celsius to synchronize cells at the G1S border. After 24 hours, wash the cells three times with PBS.
Then, add standard growth medium to the washed cells and incubate for six hours at 37 degrees Celsius. First, wash the cells with 10 milliliters of PBS. Then, add medium containing 500 nanomolar Mps1 Inhibitor reversine.
Incubate for 12 hours at 37 degrees Celsius. The following day, wash the cells three times with PBS. Then, add standard growth medium and return the plates to the incubator.
Approximately 72 hours after the first aberrant mitosis, wash the cells with 10 milliliters of PBS. Then, add medium containing 330 nanomolar nocodazole. Incubate for 12 hours at 37 degrees Celsius.
The next day, aspirate the nocodazole medium. Then add three milliliters of PBS to the dish and tap the side of the plate to shake-off the mitotic cells. Rotate the plate between each tap to allow even removal of mitotic cells.
After the initial shake-off, aspirate any liquid adhered to the lid and edge of the plate. Then, check the plate under the microscope at 10X magnification. Then wash the cells with five milliliters of PBS.
Next, add medium containing 330 nanomolar nocodazole. Incubate for 12 hours at 37 degrees Celsius. After the final shake-off, add 10 milliliters of standard growth medium.
Incubate the cells for 12 to 24 hours at 37 degrees Celsius before performing the assays. The cells remaining on the plate are referred to as arrested with complex karyotype or ArCK cells. This protocol describes a simple method to isolate ArCK cells and several features specific to ArCK cells are analyzed to confirm their isolation.
ArCK cells show increased levels of cell cycle inhibitors p53, p21, and p16 in the immunoblot analysis, while euploid and aneuploid cycling cells do not. Additionally, ArCK cells are positive for senescence associated beta-Galactosidase, which stains blue-green while euploid control cells are not. Segmentation plots reveal that ArCK cells are aneuploid, characterized by multiple, random chromosome gains and chromosome losses.
Segmentation plots show the copy number of single cells from chromosome one to X, relative to a euploid reference log two scale. While attempting this procedure, it's important to make sure to remove all mitotic cells during each shake-off. After performing this procedure, other methods such as cytokine assays can be performed.
These assays will help in answering additional questions such as the ability of ArCK cells to interact with the cells of the immune system. Don't forget that nocodazole is hazardous. Appropriate personal protective equipment should be worn while using this reagent.
Once mastered, this technique can be used to efficiently isolate ArCK cells in vitro. This procedure can be done in seven days if performed properly.
Overview
This study presents a straightforward method for isolating aneuploid cells with complex karyotypes that are arrested in the cell cycle. The technique aims to enhance understanding of aneuploidy and its implications in cellular behavior and immune interactions.
Key Study Components
Area of Science
- Cell Biology
- Genetics
- Neuroscience
Background
- Aneuploidy is associated with genome instability.
- Cells with complex karyotypes often cease to divide.
- Understanding these cells can provide insights into cancer and other diseases.
- Isolation of these cells can facilitate further research into their properties.
Purpose of Study
- To develop a method for generating and isolating cell cycle-arrested cells.
- To investigate the characteristics of aneuploid cells.
- To explore the interaction between aneuploid cells and the immune system.
Methods Used
- Synchronization of RPE-1 hTERT cells using thymidine and nocodazole.
- Cell shake-off technique to isolate mitotic cells.
- Immunoblot analysis to assess cell cycle inhibitors.
- Senescence-associated beta-Galactosidase staining for identification of ArCK cells.
Main Results
- ArCK cells exhibit increased levels of cell cycle inhibitors.
- These cells are positive for senescence-associated markers.
- Segmentation plots confirm aneuploidy in isolated cells.
- The method effectively isolates cells with complex karyotypes.
Conclusions
- The protocol provides a reliable way to study aneuploid cells.
- Isolated ArCK cells can be used for further research on immune interactions.
- Proper execution of the method can yield results within a week.
Frequently Asked Questions
Executive Industry Relevance
Isolating cell cycle-arrested cells with complex karyotypes enables mechanistic de-risking of aneuploidy-driven phenotypes in discovery biology. This approach supports target validation by providing a reproducible system to study chromosomal instability and its impact on cellular senescence, inflammation, and immune interactions. The method’s reliance on standard tissue culture techniques enhances scalability and cross-functional adoption in early-stage R&D pipelines.
Strategic Applications in Biopharma R&D
Early Discovery & Target Validation
- Scientific Value: Enables interrogation of therapeutic hypotheses linking aneuploidy to genome instability and pro-inflammatory phenotypes.
- Operational Value: Provides a standardized, low-cost workflow for generating ArCK cells using thymidine, reversine, and nocodazole synchronization.
Screening & Assay Development
- Scientific Value: Generates a defined cell population with complex karyotypes for quantitative analysis of senescence markers and cytokine secretion.
- Operational Value: Supports assay standardization through consistent isolation of arrested cells via shake-off and nocodazole treatment.
Translational & Preclinical Research
- Scientific Value: Facilitates study of aneuploid cell interactions with immune cells, informing immunomodulatory target assessment.
- Operational Value: Enables downstream functional assays such as cytokine profiling and senescence-associated beta-Galactosidase staining to validate phenotypic outputs.
Pipeline & Workflow Integration
The method fits within the discovery continuum from target hypothesis testing to phenotypic screening, particularly for mechanisms involving chromosomal instability and stress response pathways.
- Discovery Biology: Supports mechanistic de-risking by isolating cells with defined karyotypic complexity to clarify causal links between aneuploidy and cellular phenotypes.
- Screening: Enables reproducible preparation of ArCK cells for high-content analysis of cell cycle inhibitors and secretory profiles.
- Analytics: Provides quantitative outputs including immunoblot detection of p53, p21, p16 and segmentation plots for single-cell copy number variation.
- Translational Research: Connects to immune interaction studies, supporting biomarker exploration in senescence-associated secretory phenotypes.
- Enterprise Reuse: Uses accessible reagents and standard culture equipment, allowing adaptation across laboratories without specialized infrastructure.
Operational & Enterprise Impact
- Scientific Value: Reduces mechanistic ambiguity in aneuploidy research by providing a defined arrest model with complex karyotypes.
- Operational Value: Delivers a seven-day protocol with high specificity for ArCK cells, improving throughput and reproducibility.
- Strategic Value: Informs go/no-go decisions by enabling early assessment of aneuploidy-driven biological risks in target pathways.
- Portfolio Impact: Supports risk-adjusted prioritization of targets linked to chromosomal instability and senescence.
Implementation Considerations
- Requires expertise in cell synchronization techniques and mitotic shake-off procedures.
- Dependent on access to standard tissue culture incubators, hemocytometers, and fluorescence or brightfield microscopy for validation.
- Necessitates standardization of nocodazole handling and wash steps to ensure complete removal of mitotic cells across replicates.
- Adaptation to other cell lines may require optimization of thymidine, reversine, and nocodazole concentrations and timing.
- Limited to in vitro models; primary tissue or in vivo applicability not addressed in source material.
Biopharma FAQs
Chapters in this video
0:04
Title
0:32
Synchronization of RPE-1 hTERT Cells
1:34
Generation of Aneuploid Cells by Interference with the Activity of the Mitotic Kinase Mps1 and Removal of Aneuploid Cycling Cells to Enrich the ArCK Population
3:36
Results: In Vitro Isolation and Characterization of Aneuploid Cells with Complex Karyotypes (ArCK)
4:35
Conclusion
