BLM

Definition

BLM stands for Base Excision Repair, a crucial DNA repair mechanism that removes damaged or non-canonical bases from the DNA strand and replaces them with the correct ones. This process is vital for maintaining genomic stability, as it helps prevent mutations that could lead to various diseases, including cancer. BLM also refers to the Bloom syndrome gene, which plays a significant role in the maintenance of DNA integrity and repair processes, linking it directly to cellular responses to DNA damage.

5 Must Know Facts For Your Next Test

1. BLM is essential for repairing non-helix-distorting lesions in DNA, helping to maintain genetic fidelity.
2. The Bloom syndrome gene, when mutated, leads to an increased risk of cancer due to impaired DNA repair mechanisms.
3. BLM functions by first recognizing damaged bases, followed by excision, followed by synthesis of the correct base to restore DNA integrity.
4. Defects in BLM-related repair pathways can result in chromosomal instability, which is a hallmark of many cancers.
5. Base excision repair is particularly important in response to oxidative stress, as reactive oxygen species can cause base modifications.

Review Questions

• How does Base Excision Repair contribute to cellular health and what are the consequences of its failure?
  • Base Excision Repair (BER) is vital for maintaining cellular health by correcting small-scale DNA damage that could lead to mutations. When BER fails, damaged bases remain in the DNA, potentially leading to errors during replication and ultimately resulting in mutations that can cause diseases like cancer. This repair mechanism ensures genomic stability, emphasizing its importance in preventing genomic disorders.
• Discuss the relationship between the Bloom syndrome gene and its role in maintaining DNA integrity.
  • The Bloom syndrome gene encodes a helicase involved in various DNA processes, including replication and repair. Mutations in this gene compromise the cell's ability to conduct efficient DNA repair through mechanisms such as homologous recombination and base excision repair. This impairment leads to increased rates of chromosomal abnormalities and a heightened predisposition to cancer, underscoring the gene's critical role in maintaining genomic integrity.
• Evaluate how disruptions in Base Excision Repair mechanisms can impact cancer therapy and patient outcomes.
  • Disruptions in Base Excision Repair mechanisms can significantly impact cancer therapy by altering tumor cell responses to chemotherapeutic agents. Many cancer treatments induce DNA damage; if BER is compromised, cancer cells may become more resistant to these therapies due to an inability to effectively repair induced lesions. Consequently, understanding BLM and related pathways not only aids in predicting treatment responses but also helps tailor personalized approaches to improve patient outcomes.

Related terms

DNA Glycosylases: Enzymes that initiate base excision repair by recognizing and removing damaged bases from DNA.

Nucleotide Excision Repair (NER): A DNA repair mechanism that removes bulky DNA adducts and repairs extensive DNA damage involving multiple bases.

Homologous Recombination: A DNA repair process that uses a homologous sequence as a template to accurately repair double-strand breaks in DNA.