Between 2002-2005, probands from 300 US families with 4 or more cases of breast or ovarian cancer but with negative (wild-type) commercial genetic test results for BRCA1 and BRCA2 were screened by multiple DNA-based and RNA-based methods to detect genomic rearrangements in BRCA1 and BRCA2 and germline mutations of all classes in CHEK2, TP53, and PTEN.
BRCA1 and BRCA2 mutations confer very high risks of breast and ovarian cancer. p53 and PTEN mutations lead to very high breast cancer risks associated with rare cancer syndromes.
One patient exhibited mutations both in PIK3CA and PTEN at discordant sites between endometrial and ovarian carcinomas, whereas the other 4 exhibited concordant mutations.
Among several series of ovarian cancers, the frequency of loss of heterozygosity (LOH) of markers flanking and within PTEN, is approximately 30 to 50%, and the somatic intragenic PTEN mutation frequency is <10%.
In these cases, there is a high frequency of atypia in the endometriosis, and the endometriosis and the associated ovarian carcinoma may show identical PTEN mutations.
Alterations in beta-catenin and PTEN genes, as well as MSI, are frequent in low-stage ovarian carcinomas of endometrioid type that have a favorable prognosis.
In two of the five cases of clinically synchronous cancers, identical or progressive PTEN mutations were found in both the endometrial and ovarian cancers, suggesting that the ovarian tumor is a metastasis from the endometrial primary.
PTEN, a tumor suppressor commonly mutated (50%) in endometrial carcinoma, is found mutated in endometrioid carcinoma of the ovary, but not in other forms of ovarian cancer.
Although many tumors presented a single lesion (28/93, of which 23 overexpressed PIK3CA, 1 overexpressed AKT and 4 had lost PTEN), many OC (35/93) presented multiple alterations within the PI3K pathway.
Subcutaneously transplanted nude mice, as a model of human ovarian cancer, were used to test the effects of PTEN and KRT10 on cisplatin resistance of ovarian cancer in vivo.
The purpose of this study was to determine whether upregulation of PTEN gene by transfection wild-type PTEN gene to ovarian cancer cells can inhibit growth and migration and to explore the potential for PTEN gene therapy of ovarian cancers.
These findings indicate that deregulation of miRNAs is a recurrent event in human ovarian cancer and that miR-214 induces cell survival and cisplatin resistance primarily through targeting the PTEN/Akt pathway.