Related Experiment Videos
Search for oncogene mutations in X-ray-transformed mouse 10T1/2 cells by denaturing gradient gel electrophoresis
1Laboratory of Radiobiology, Harvard School of Public Health, Boston, MA 02115.
Abstract:
We have sought evidence for possible mutations within the c-myc, c-Ha-ras and c-Ki-ras loci of X-ray-transformed mouse C3H10T1/2 cell clones using the denaturing gradient gel electrophoresis (DGGE) blot technique. This highly sensitive method was developed to detect any mutations (e.g. single base changes, small deletions) in genomic DNA, by measuring differences in the melting behaviour of short DNA fragments (50-800 bp) obtained by digestion of genomic DNA with several specific 4 bp recognition site restriction enzymes. In this study, genomic DNAs derived from 23 X-ray-transformed clones were digested with several restriction enzymes, electrophorezed on denaturing gradient gel and hybridized to c-myc, c-Ha-ras and c-Ki-ras cDNA probes. No alterations in melting patterns were observed for any of these oncogenes as compared with DNA from 18 control, non-irradiated wild-type 10T1/2 cell clones, suggesting that transformation was not associated with mutation of these genes nor with changes in their patterns of methylation. However, our screening of the large portion of exons 2 and 3 of c-myc as well as of exons 1 and 2 of c-Ha-ras gene cannot exclude the possibility that some sequence differences in the high melting domains of examined fragments were not detected by this assay.
Insights
Researchers investigated mutations in key oncogenes (c-myc, c-Ha-ras, c-Ki-ras) in X-ray-transformed cells. The study found no evidence of mutations in these specific genes, suggesting transformation is not linked to their alteration.
Area of Science:
- Molecular biology
- Cancer research
- Genetics
Background:
- X-ray transformation of mouse C3H10T1/2 cells is a model for studying oncogenesis.
- Oncogenes like c-myc, c-Ha-ras, and c-Ki-ras are frequently implicated in cancer development.
- Detecting mutations in specific gene loci is crucial for understanding cancer mechanisms.
Purpose of the Study:
- To investigate for mutations in the c-myc, c-Ha-ras, and c-Ki-ras genes of X-ray-transformed mouse C3H10T1/2 cell clones.
- To determine if X-ray-induced cell transformation is associated with alterations in these specific oncogenes.
- To assess changes in DNA methylation patterns of these oncogenes.
Main Methods:
- Utilized denaturing gradient gel electrophoresis (DGGE) blot technique for sensitive mutation detection.
- Analyzed genomic DNA from 23 X-ray-transformed clones and 18 control clones.
- Employed restriction enzyme digestion, electrophoresis, and hybridization with c-myc, c-Ha-ras, and c-Ki-ras cDNA probes.
Main Results:
- No alterations in melting patterns were observed for c-myc, c-Ha-ras, or c-Ki-ras genes in transformed cells compared to controls.
- The findings suggest that X-ray-induced transformation was not associated with mutations in these examined oncogenes.
- No changes in the methylation patterns of these oncogenes were detected.
Conclusions:
- The study did not find evidence of mutations in the screened portions of c-myc, c-Ha-ras, and c-Ki-ras genes in X-ray-transformed C3H10T1/2 cells.
- The results indicate that transformation in this model system may not involve mutations in these specific oncogenes.
- The limitations of the DGGE technique mean that undetected sequence differences in specific domains cannot be entirely ruled out.