Our data suggest that the BRCA1 and/or other genes within the interval between BRCA1 and D17S856 on 17q21 may be important in the pathogenesis of prostate cancer.
Our results suggest that a potential tumor suppressor gene(s) may reside in the < 2 Mb region centromeric (inclusive) to the BRCA1 gene and that this tumor suppressor gene(s) may be involved in the formation of prostate cancer.
Analysis of polymorphic loci on 17q in the series of hybrid clones suggested that a tumor suppressor gene associated with prostate cancer was located in a region no more than 28 cM long at 17q12-q22, which includes the BRCA1 gene involved in hereditary breast cancer.
The data suggest that the region distal to BRCA1 may contain 1 or more prostate-specific tumor suppressor genes and that BRCA1 itself plays only a minor role in prostate cancer development.
Further evidence comes from the increased risk of prostate cancer in BRCA1 mutation carriers but more particularly from the recent report of the mapping of a prostate cancer susceptibility gene to chromosome 1.
Four microsatellite polymorphic markers (D8S133, D8S136, and D8S137, for a putative tumor suppressor gene on chromosome 8p, and D17S855, for the BRCA1 gene on chromosome 17q) were used to examine the pattern of allelic loss in prostate cancer from 19 patients who had two or more distantly separate tumors (i.e., located on contralateral sides or separated by at least half the anterior-posterior diameter of the prostate).
We stably expressed wild-type (wt) and tumor-associated mutant BRCA1 transgenes in DU-145, a human prostate cancer cell line with low endogenous expression of BRCA1.
We tested for the BRCA1185delAG frameshift mutation, found in 0.9% of Ashkenazi Jews, and the BRCA2 6174delT mutation, found in 1% of Ashkenazi Jews, in Ashkenazi Jewish men with prostate cancer.
These data suggest that microsatellite instability and loss of unidentified genes on chromosome 8p may be involved in carcinogenesis of the prostate; however, BRCA1 and BRCA2 may not be largely involved in the development of prostate cancer in the Japanese population.
Genes underlying these cancers are now recognized in colorectal cancer (APC, mismatch repair genes, LKB1) and in breast cancer (BRCA1, BRCA2) whereas, in prostate cancer, a locus in chromosome 1 (HPC1) has been proposed on the basis of linkage analysis.
Previous studies indicate that beclin 1 maps to a region approximately 150 kb centromeric to BRCA1 on chromosome 17q21 that is commonly deleted in breast, ovarian, and prostate cancer.
BRCA1 mutation detection was performed on a family having four confirmed cases of ovarian cancer, two cases of breast cancer, and one case each of colon, stomach, and prostate cancer.
Examination of other breast and prostate cancer cell lines revealed that sensitivity to the anti-proliferative effects of 1alpha, 25(OH)2D3 was strongly associated with an ability to modulate BRCA1 protein.
Blood DNA from affected individuals in 38 prostate cancer clusters was analyzed for germ-line mutations in BRCA1 and BRCA2 to assess the contribution of each of these genes to familial prostate cancer.
Although mutations of the breast cancer susceptibility gene 1 (BRCA1) may play important roles in breast and prostate cancers, the detailed mechanism linking the functions of BRCA1 to these two hormone-related tumors remains to be elucidated.
In this study, 22 high-risk prostate cancer families (at least three cases of prostate cancer) were screened by conformation-sensitive gel electrophoresis (CSGE) for mutations in BRCA1 and BRCA2.
These findings indicate that BRCA1 interacts with the components of the JAK-STAT signaling cascade and modulates its activation, which may provide a new critical survival signal for the growth of breast, ovarian and prostate cancers in the presence of normal BRCA1.
The BRCA1 gene was previously found to inhibit the transcriptional activity of the estrogen receptor [ER-alpha] in human breast and prostate cancer cell lines.
A second breast cancer susceptibility gene (BRCA2) operates in some of the same molecular pathways as BRCA1, and mutations of this gene predispose to breast and ovarian cancer and probably to other tumor types, including prostate cancer.