DNA Repair Genes Polymorphisms: Impact on Acute Myeloid Leukemia Patients Outcome

Salah Aref1, Nadia El Menshawy1, Tarek Abou Zeid2

  • 1Hematology Unit, Clinical Pathology Department, Faculty of Medicine, Mansoura University, Egypt.

Abstract

Insights

Specific gene variants in ATM, XRCC6, and LIG4 are linked to lower gene expression in Acute Myeloid Leukemia (AML) patients. This reduced expression impacts patient survival, suggesting a role in therapy optimization.

Area of Science:

  • Genetics
  • Molecular Biology
  • Oncology

Background:

  • ATM, XRCC6, and LIG4 genes are crucial for DNA double-strand break repair and genome stability.
  • Single nucleotide polymorphisms (SNPs) in these genes can alter their expression and function.
  • Understanding SNP effects is vital for assessing their impact on disease outcomes.

Purpose of the Study:

  • To investigate the effect of specific SNPs in DNA repair genes (ATM, XRCC6, LIG4) on gene expression.
  • To determine the association between these gene expression changes and patient outcomes in Acute Myeloid Leukemia (AML).

Main Methods:

  • Cross-sectional study of 95 newly diagnosed AML patients.
  • Evaluation of SNPs (ATM rs189037, XRCC6 rs2267437, LIG4 rs1805388) using Restriction Fragment Length Polymorphism (RFLP).
  • Quantification of gene expression using real-time PCR.

Main Results:

  • Specific SNPs (ATM AA, XRCC6 GG, LIG4 TT) were associated with significant downregulation of corresponding genes (P<0.001).
  • Lower expression of ATM and LIG4 correlated with shorter Overall Survival (OS) and Disease-Free Survival (DFS).
  • Multivariate analysis indicated lower ATM expression as a predictor for OS (HR: 2.02, P=0.020).

Conclusions:

  • Identified SNPs in ATM, XRCC6, and LIG4 are linked to reduced gene expression.
  • Lower ATM and XRCC6 expression predict poorer OS, while lower ATM expression predicts poorer DFS.
  • These findings suggest potential for using these genetic markers in optimizing AML therapy.

Related Concept Videos

Nucleotide Excision Repair01:38

Nucleotide Excision Repair

DNA Distortion and Damage
Cells are regularly exposed to mutagens—factors in the environment that can damage DNA and generate mutations. UV radiation is one of the most common mutagens and is estimated to introduce a significant number of changes in DNA. These include bends or kinks in the structure, which can block DNA replication or transcription. If these errors are not fixed, the damage can cause mutations, which in turn can result in cancer or disease depending on which sequences are...
3.7K
Mismatch Repair01:20

Mismatch Repair

Organisms are capable of detecting and fixing nucleotide mismatches that occur during DNA replication. This sophisticated process requires identifying the new strand and replacing the erroneous bases with correct nucleotides. Mismatch repair is coordinated by many proteins in both prokaryotes and eukaryotes.
The Mutator Protein Family Plays a Key Role in DNA Mismatch Repair
The human genome has more than 3 billion base pairs of DNA per cell. Prior to cell division, that vast amount of genetic...
5.1K
Overview of DNA Repair02:25

Overview of DNA Repair

In order to be passed through generations, genomic DNA must be undamaged and error-free. However, every day, DNA in a cell undergoes several thousand to a million damaging events by natural causes and external factors. Ionizing radiation such as UV rays, free radicals produced during cellular respiration, and hydrolytic damage from metabolic reactions can alter the structure of DNA. Damages caused include single-base alteration, base dimerization, chain breaks, and cross-linkage.
Chemically...
31.4K
Base Excision Repair01:54

Base Excision Repair

One of the common DNA damages is the chemical alteration of single bases by alkylation, oxidation, or deamination. The altered bases cause mispairing and strand breakage during replication. This type of damage causes minimal change to the DNA double helix structure and can be repaired by the base excision repair (BER) pathways. BER corrects damaged DNA sequences by removing the damaged base and restoring the original base sequence using the complementary strand as a template.
The first step of...
22.8K
Long-patch Base Excision Repair01:02

Long-patch Base Excision Repair

Since the discovery of the two BER pathways, there has been a debate about how a cell chooses one pathway over the other and the factors determining this selection. Numerous in vitro experiments have pointed out multiple determinants for the sub-pathway selection. These are:
7.1K
Fixing Double-strand Breaks02:04

Fixing Double-strand Breaks

The double-stranded structure of DNA has two major advantages. First, it serves as a safe repository of genetic information where one strand serves as the back-up in case the other strand is damaged. Second, the double-helical structure can be wrapped around proteins called histones to form nucleosomes, which can then be tightly wound to form chromosomes. This way, DNA chains up to 2 inches long can be contained within microscopic structures in a cell. A double-stranded break not only damages...
12.8K