Expression variations of DNA damage response genes ATM and ATR in blood cancer patients

Aamir Parvez1, Ishrat Mahjabeen1, Azhar Mehmood1

  • 1Cancer Genetics and Epigenetics Laboratory, Department of Biosciences, COMSATS University Islamabad, Park Road Tarlai Kalan, Islamabad, Pakistan.

Hematological malignancies (HM) constitute a variety of cancers originating in blood, bone marrow (BM), and lymphatic systems. During the last two decades, the incidence of HM has dramatically increased worldwide. The etiology of HM is still debatable. Genetic instability is a major risk factor for HM. DDR network is a complex signal transduction cellular machinery that detects DNA damage and activates cellular repair factors, thus maintaining genomic integrity. DDR network detects a variety of DNA damage and triggers the activation of cell cycle control, DNA repair, senescence, and apoptosis. Among the DNA repairing pathways, the DNA damage response (DDR) pathway includes DNA damage signaling apparatus such as ATM and ATR genes. ATM tends to detect double-strand breaks (DSBs) while ATR detects single-strand DNA (ssDNA). The study was conducted to observe the expression deregulations of DNA damage response (DDR) pathway genes (ATM, ATR) at mRNA level in 200 blood cancer patients and 200 controls. The real-time PCR was used to analyze the expression of the target genes. The expression results showed statistically significant downregulation of ATM (p < 0.0001) and ATR (p < 0.0001) genes in blood cancer patients vs. controls. Moreover, a significant downregulation of ATM (p < 0.0001) and ATR (p < 0.0001) was obtained in chemotherapy-treated patients vs. healthy controls. The results suggest that dysregulation in ATM and ATR genes may be associated with increased blood cancer risk.

Related Concept Videos

DNA Damage can Stall the Cell Cycle02:37

DNA Damage can Stall the Cell Cycle

In response to DNA damage, cells can pause the cell cycle to assess and repair the breaks. However, the cell must check the DNA at certain critical stages during the cell cycle. If the cell cycle pauses before DNA replication, the cells will contain twice the amount of DNA. On the other hand, if cells arrest after DNA replication but before mitosis, they will contain four times the normal amount of DNA. With a host of specialized proteins at their disposal,cells must use the right protein at...
9.2K
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...
3.6K
The Intrinsic Apoptotic Pathway01:31

The Intrinsic Apoptotic Pathway

Internal cellular stress, such as cellular injury or hypoxia, triggers intrinsic apoptosis. The B-cell lymphoma 2 (Bcl-2) family of proteins are the primary regulators of the intrinsic apoptotic pathway. For example, during DNA damage, checkpoint proteins, such as Ataxia Telangiectasia Mutated (ATM protein) and Checkpoints Factor-2 (Chk2) proteins, are activated. These proteins phosphorylate p53 which further activates pro-apoptotic proteins, such as Bax, Bak, PUMA, and Noxa, and inhibits...
6.6K
DNA Damage Can Stall the Cell Cycle02:37

DNA Damage Can Stall the Cell Cycle

2.6K
Mutations01:35

Mutations

Mutations are changes in the sequence of DNA. These changes can occur spontaneously or they can be induced by exposure to environmental factors. Mutations can be characterized in a number of different ways: whether and how they alter the amino acid sequence of the protein, whether they occur over a small or large area of DNA, and whether they occur in somatic cells or germline cells.
Chromosomal Alterations Are Large-Scale Mutations
While point mutations are changes in a single nucleotide in...
38.3K
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...
31.2K