Related Experiment Videos
ras and p53 genes in male breast cancer
P J Dawson1, K R Schroer, S R Wolman
1Department of Pathology & Laboratory Medicine, University of South Florida, Tampa 33612, USA.
Abstract:
We have studied the roles of Ki-ras oncogene and p53 tumor suppressor gene in a series of 20 cases of male breast cancer and one papilloma of the male breast. Ki-ras was detected in 50-microns sections after digestion with proteinase K and SDS. DNA was amplified by polymerase chain reaction, dot blotted, and mutations were screened with labeled ras mutation-specific oligonucleotides. Wild-type and mutant p53 protein were detected with antibodies CM1 and DO7, using the avidin-biotin-peroxidase method. Two of 17 carcinomas showed Ki-ras mutations, both in codon 12 (gly --> lys and gly --> arg). Five of 20 male breast cancers (25%), including one large intraductal carcinoma, expressed mutant p53 protein. Although the incidence of mutant p53 expression in male breast cancer is similar to that in women, Ki-ras mutations are not significantly increased.
Insights
This study investigated the Ki-ras oncogene and p53 tumor suppressor gene in male breast cancer. Ki-ras mutations were infrequent, while mutant p53 protein expression was observed in 25% of cases, similar to female breast cancer.
Area of Science:
- Oncology
- Molecular Biology
- Genetics
Background:
- Male breast cancer is rare, and the molecular alterations driving its development are not well understood.
- Investigating oncogenes and tumor suppressor genes provides insight into cancer pathogenesis.
Purpose of the Study:
- To examine the roles of the Ki-ras oncogene and p53 tumor suppressor gene in male breast cancer.
- To compare the molecular profiles with those found in female breast cancer.
Main Methods:
- Analysis of 20 male breast cancer cases and one papilloma.
- Detection of Ki-ras mutations using polymerase chain reaction and oligonucleotide screening.
- Assessment of p53 protein expression (wild-type and mutant) via immunohistochemistry.
Main Results:
- Ki-ras mutations were found in 2 of 17 carcinomas, specifically in codon 12.
- Mutant p53 protein was expressed in 5 of 20 male breast cancer cases (25%).
- The incidence of mutant p53 expression was comparable to that observed in female breast cancer.
Conclusions:
- Ki-ras mutations are not significantly increased in male breast cancer.
- Mutant p53 protein expression occurs in a subset of male breast cancers at a rate similar to female breast cancer.
- Further research is needed to elucidate the specific molecular pathways in male breast cancer.