Related Experiment Videos
Somatic mutations and human breast cancer. A status report
R Callahan1, C S Cropp, G R Merlo
1National Cancer Institute, Bethesda, MD 20892.
Cancer
|March 15, 1992
Summary
This study analyzed human breast tumor DNA, finding frequent amplification of proto-oncogenes and loss of heterozygosity (LOH) on multiple chromosomes. Specific mutation patterns define tumor subsets, with p53 gene mutations common in 17p LOH cases.
Area of Science:
- Oncology
- Genetics
- Molecular Biology
Background:
- Primary human breast tumors exhibit genetic alterations.
- Proto-oncogenes and tumor suppressor genes play critical roles in tumorigenesis.
Purpose of the Study:
- To systematically analyze genetic alterations in primary human breast tumors.
- To identify frequently amplified proto-oncogenes and regions with loss of heterozygosity (LOH).
- To investigate the prevalence of p53 gene mutations in relation to LOH.
Main Methods:
- Systematic DNA analysis of primary human breast tumors.
- Detection of proto-oncogene amplification (c-myc, int-2, c-erbB2).
- Assessment of loss of heterozygosity (LOH) across various chromosomal regions.
- Comprehensive molecular analysis of the p53 gene.
Main Results:
- Frequent amplification of c-myc, int-2, and c-erbB2 proto-oncogenes observed.
- Significant LOH detected on chromosomes 1p, 1q, 3p, 7, 11p, 13q, 17p, 17q, and 18q.
- Specific tumor subsets identified by distinct mutation profiles, e.g., co-occurring LOH on 11p, 17p, and 18q.
- Point mutations in the p53 gene found in 46% of tumors analyzed, particularly those with 17p LOH.
Conclusions:
- Genetic alterations, including proto-oncogene amplification and LOH, are common in human breast tumors.
- Distinct genetic profiles can stratify breast tumors into specific subsets.
- The p53 gene is frequently mutated in breast tumors, suggesting its role as a tumor suppressor.
- Further research into tumor suppressor genes within LOH regions is warranted.