Related Experiment Videos
N-ras mutations in radiation-induced murine leukemic cells
K N Rithidech1, J J Dunn, C R Gordon
1Medical Department, Brookhaven National Laboratory, Upton, NY 11973-5000, USA. rithidech@bnlarm.bnl.gov
Blood Cells, Molecules & Diseases
|January 1, 1996
Summary
Fast neutrons induce more N-ras mutations in radiation-induced myeloid leukemia (ML) in mice. These N-ras mutations are not the initial cause of radiation leukemogenesis, appearing later in the disease progression.
Area of Science:
- Molecular biology
- Radiation oncology
- Genetics
Background:
- Radiation exposure can induce genetic mutations leading to cancer.
- The N-ras gene is frequently implicated in myeloid leukemia (ML).
- Understanding the role of specific radiation types in mutagenesis is crucial for risk assessment.
Purpose of the Study:
- To investigate N-ras gene mutations in radiation-induced ML in mice.
- To compare mutation frequencies induced by different radiation qualities (neutrons vs. photons).
- To determine if N-ras mutations are an initiating event in radiation leukemogenesis.
Main Methods:
- DNA extraction from spleen cells of CBA/Ca mice with induced ML.
- Analysis of N-ras gene exons I, II, and III using Polymerase Chain Reaction-Single Strand Conformational Polymorphism (PCR-SSCP).
- Direct DNA sequencing of PCR products to identify mutation types and locations.
Main Results:
- N-ras mutations were exclusively found in exon II of the N-ras gene.
- Mutations were more prevalent in ML cases induced by fast neutrons compared to photons.
- Silent point mutations and a base transversion in codon 61 were identified.
- N-ras mutations were detected only in overt ML cases, not in early stages.
Conclusions:
- Fast neutrons are more effective than photons in inducing genomic instability at the N-ras locus.
- N-ras mutations are not the initiating event in radiation-induced myeloid leukemia.
- N-ras mutations likely occur downstream of the initiating event in leukemogenesis.