Related Experiment Video

Updated: Aug 14, 2026

In Vitro Scratch Assay to Demonstrate Effects of Arsenic on Skin Cell Migration
09:24

In Vitro Scratch Assay to Demonstrate Effects of Arsenic on Skin Cell Migration

Published on: February 23, 2019

Lack of poly(ADP-ribose) polymerase-1 gene product enhances cellular sensitivity to arsenite

Anuradha Poonepalli1, Lakshmidevi Balakrishnan, Aik Kia Khaw

  • 1Genome Stability Laboratory, Department of Physiology, National University of Singapore.

Cancer Research
|December 3, 2005
PubMed

Insights

Poly(ADP-ribose) polymerase-1 (PARP-1) is crucial for maintaining genomic stability against arsenite exposure. PARP-1 deficiency exacerbates arsenite-induced DNA damage, telomere attrition, and cell death, highlighting its protective role.

Area of Science:

  • Toxicology
  • Genetics
  • Molecular Biology

Background:

  • Arsenite (As3+) is a known carcinogen that causes toxicity partly through reactive oxygen species generation.
  • Identifying genetic factors influencing arsenic mutagenicity and carcinogenicity is vital for public health.
  • Poly(ADP-ribose) polymerase (PARP) plays a key role in maintaining genomic DNA stability.

Purpose of the Study:

  • To investigate the role of PARP-1 in the cytotoxic and genotoxic effects induced by arsenite.
  • To understand how PARP-1 deficiency impacts cellular responses to arsenite exposure.

Main Methods:

  • Comparison of arsenite effects on PARP-1 knockout (PARP-1-/-) and wild-type (PARP-1+/+) mouse embryonic fibroblasts (MEFs).
  • Assessment of telomere attrition, DNA damage (alkaline comet assay), micronuclei induction, and gene expression changes (microarray).

Main Results:

  • PARP-1-/- MEFs exhibited significantly more telomere attrition (40%) than PARP-1+/+ MEFs (10-20%) after arsenite treatment.
  • PARP-1 deficiency led to elevated DNA damage and increased micronuclei induction, indicating impaired DNA repair and genomic instability.
  • A correlation between telomere reduction and enhanced apoptotic death was observed in PARP-1 null cells.
  • Arsenite treatment altered the expression of approximately 311 genes, primarily involved in stress response and cell maintenance.

Conclusions:

  • PARP-1 plays a critical role in protecting cells against arsenite-induced genotoxicity and cytotoxicity.
  • Telomere attrition may act as a trigger for enhanced apoptosis in PARP-1 deficient cells exposed to arsenite.
  • PARP-1 is essential for maintaining chromosome and genome stability following arsenite-induced DNA damage.

More Related Videos

Visualization and Quantitative Analysis of Genotoxin-Induced PARP1/PARP2 Activation in Cells Using a Fluorescent Fusion Protein-Based Reporter07:53

Visualization and Quantitative Analysis of Genotoxin-Induced PARP1/PARP2 Activation in Cells Using a Fluorescent Fusion Protein-Based Reporter

Published on: April 17, 2026

Related Concept Videos

Pharmacogenetics of Drug Targets: β₂-Adrenergic Receptors, Apo E, Thymidylate Synthase01:11

Pharmacogenetics of Drug Targets: β₂-Adrenergic Receptors, Apo E, Thymidylate Synthase

Genetic polymorphisms in drug targets have emerged as critical determinants of interindividual variability in drug response and toxicity. Pharmacogenomic investigations increasingly focus on identifying these variations to personalize and optimize therapeutic interventions. A drug target may be a receptor, enzyme, or signaling protein involved in pharmacologic responses or disease-related pathways. While early pharmacogenetic studies focused primarily on drug metabolism, current research...
Abnormal Proliferation02:23

Abnormal Proliferation

Under normal conditions, most adult cells remain in a non-proliferative state unless stimulated by internal or external factors to replace lost cells. Abnormal cell proliferation is a condition in which the cell's growth exceeds and is uncoordinated with normal cells. In such situations, cell division persists in the same excessive manner even after cessation of the stimuli, leading to persistent tumors. The tumor arises from the damaged cells that replicate to pass the damage to the daughter...
Biosynthesis of Nucleic Acids01:28

Biosynthesis of Nucleic Acids

Nucleic acid biosynthesis is a fundamental biochemical process that produces the purine and pyrimidine nucleotides essential for DNA and RNA synthesis. This pathway maintains a balanced nucleotide pool, preventing imbalances that could jeopardize genetic integrity and cellular function. Given the crucial role of nucleotides, their synthesis is tightly regulated to ensure proper cellular homeostasis.Purine BiosynthesisThe biosynthesis of purine nucleotides begins with ribose-5-phosphate, a...
Stringent Response in E. coli01:23

Stringent Response in E. coli

Bacterial growth is closely tied to nutrient availability, with cells proliferating exponentially under favorable conditions and entering a stationary phase when resources become scarce. This transition is mediated by a regulatory mechanism known as the stringent response, which allows bacteria to adapt to nutrient deprivation by modulating gene expression and metabolic activity.During nutrient scarcity, intracellular amino acid levels decline. It results in the accumulation of uncharged tRNAs...
Allosteric Proteins-ATCase01:19

Allosteric Proteins-ATCase

Binding sites linkages can regulate a protein's function.  For example, enzyme activity is often regulated through a feedback mechanism where the end product of the biochemical process serves as an inhibitor.
Aspartate transcarbamoylase (ATCase) is a cytosolic enzyme that catalyzes the condensation of L-aspartate and carbamoyl phosphate to  N-carbamoyl-L-aspartate. This reaction is the first step in pyrimidine biosynthesis. UTP and CTP, the end products of the pyrimidine synthesis pathway,...
Diversity of Archaea IV01:29

Diversity of Archaea IV

Hyperthermophilic archaea are a group of extremophiles thriving at temperatures above 80°C, often in hydrothermal vents and volcanic soils where conditions surpass the boiling point of water. At such temperatures, proteins, membranes, and DNA in most organisms degrade, but hyperthermophiles have evolved remarkable adaptations to maintain stability and function.Unique Cellular FeaturesHyperthermophilic membranes are composed of a monolayer of biphytanyl tetraether lipids, which resist thermal...