Related Experiment Video
Updated: Aug 29, 2026
The Micronucleus Assay on Cryopreserved Whole Blood
Published on: February 23, 2024
Influence of altered apoptosis in human lymphoblastoid cell lines on micronucleus frequency
Vladimir Vukicevic1, Katja Kampfinger, Helga Stopper
1Department of Toxicology, University of Würzburg, D-97078 Würzburg, Germany.
Abstract:
Defects in apoptosis play a decisive role in both tumorigenesis and drug resistance in tumor treatment. The purpose of this study was to investigate the balance between formation of genomic damage and induction of apoptosis upon genotoxic stress. For this, we influenced the apoptotic response and measured the amount of genomic damage expressed as micronucleus formation after treatment with the topoisomerase II inhibitor etoposide. Apoptosis was reduced by the addition of pifithrin (PFT) alpha and enhanced by transient transfection with bcl-2 antisense-oligonucleotide in Bcl-2-overexpressing cells. We used three human lymphoblastoid cell lines with different p53 status (TK6, wild-type p53; WTK1, mutated p53; NH32, p53 double knockout). Under conditions of reduced apoptosis, micronucleus formation was also reduced. When apoptosis was increased, micronucleus formation remained unchanged or was also increased. Overall, we did not find an expected inverse correlation between induction of apoptosis and genomic damage.
Insights
This study explored the link between apoptosis and genomic damage. Researchers found no inverse correlation, indicating that reduced apoptosis did not necessarily increase DNA damage, contrary to expectations.
Area of Science:
- Cell Biology
- Genetics
- Cancer Research
Background:
- Defects in apoptosis are crucial in cancer development and treatment resistance.
- Understanding the interplay between DNA damage and apoptosis is vital for effective cancer therapies.
Purpose of the Study:
- To investigate the relationship between genomic damage formation and apoptosis induction under genotoxic stress.
- To determine if reduced apoptosis leads to increased genomic damage.
Main Methods:
- Utilized three human lymphoblastoid cell lines with varying p53 statuses (wild-type, mutated, and knockout).
- Administered etoposide, a topoisomerase II inhibitor, to induce genotoxic stress.
- Modulated apoptosis using pifithrin alpha (to reduce) and bcl-2 antisense-oligonucleotide (to enhance).
- Quantified genomic damage via micronucleus formation.
Main Results:
- Reduced apoptosis led to a decrease in micronucleus formation.
- Increased apoptosis resulted in unchanged or increased micronucleus formation.
- The study did not observe the anticipated inverse correlation between apoptosis induction and genomic damage.
Conclusions:
- The balance between apoptosis and genomic damage is complex and not inversely correlated as hypothesized.
- Findings suggest that modulating apoptosis may not directly predict changes in genomic damage levels in response to genotoxic agents.
