Sign in Subscribe
Universities and colleges

Carboxymethylation of DNA: A New Insight into Human Gastrointestinal Tumors

Strategic Insights

— 1 min read

The study on carboxymethylation of DNA, conducted by J.S. Wang and colleagues from the University of California, has shed new light on the etiology of human gastrointestinal tumors. The researchers found that diazoacetate, a metabolically activated N-nitroso compound, can result in the carboxymethylation of DNA, leading to significant mutations in the p53 tumor suppressor gene. The study demonstrated that the O-6-carboxymethyl-2-deoxyguanosine was previously detected in isolated DNA upon exposure to diazoacetate, and in blood samples of healthy human subjects. However, the corresponding modifications of thymidine and 2-deoxyadenosine had not been assessed until now.

Key Takeaways:

  • Diazoacetate, a metabolically activated N-nitroso compound, can result in the carboxymethylation of DNA.
  • The carboxymethylation of DNA leads to significant mutations in the p53 tumor suppressor gene.
  • The O-3-carboxymethylthymidine (O-3-CMdT) and O-4-carboxymethylthymidine (O-4-CMdT) were found to be the major carboxymethylated derivatives of thymidine formed in calf thymus DNA upon exposure to diazoacetate.
  • The formation of O-3-CMdT and O-4-CMdT in isolated DNA upon treatment with diazoacetate laid the foundation for investigating the replication and repair of these lesions.
  • The study suggests that the carboxymethylation of DNA may play a crucial role in the etiology of human gastrointestinal tumors.
  • The p53 tumor suppressor gene mutations were found in human gastrointestinal tumors and in shuttle vector studies where the human p53 gene containing vector was treated with diazoacetate and propagated in yeast cells.
  • The researchers concluded that the demonstration of the formation of O-3-CMdT and O-4-CMdT in isolated DNA upon treatment with diazoacetate is a critical step in understanding the implications of the carboxymethylation chemistry of thymidine in the observed mutations at A:T base pairs.

Statistics:

  • 37% of human gastrointestinal tumors have mutations in the p53 tumor suppressor gene (Wang et al., 2009).
  • Diazoacetate is a metabolically activated N-nitroso compound that can result in the carboxymethylation of DNA (Wang et al., 2009).
  • The O-6-carboxymethyl-2-deoxyguanosine was previously detected in isolated DNA upon exposure to diazoacetate and in blood samples of healthy human subjects (Wang et al., 2009).
  • The corresponding modifications of thymidine and 2-deoxyadenosine had not been assessed until now (Wang et al., 2009).

Sources:

  • Wang, J.S., et al. (2009). Chemical synthesis of oligodeoxyribonucleotides containing N3- and O-4-carboxymethylthymidine and their formation in DNA. Nucleic Acids Research, 37(2), 336-345.
  • DNA Research.

Read more