Related Experiment Videos
Genetic alterations on chromosome 17 distinguish different types of epithelial ovarian tumors
M Pieretti1, D E Powell, H H Gallion
1Department of Pathology, Markey Cancer Center, University of Kentucky Medical Center, Lexington 40536-0093, USA.
Abstract:
Epithelial tumors of the ovary are the most common ovarian tumors of adult women. They exist in several different histological patterns and exhibit varying degrees of aggressiveness. Molecular genetic studies in epithelial ovarian cancer have shown that loss of heterozygosity (LOH) for regions of chromosome 17 is a common event, probably reflecting the inactivation of one or more tumor suppressor genes present on this chromosome. We examined 87 sporadic epithelial ovarian tumors of different grade and histological type at 16 loci on this chromosome and found that 35% of them showed LOH for chromosome 17. Of these, 84% showed LOH for all informative markers, suggesting that loss of the entire chromosome 17 homologue may have occurred. Interestingly, chromosome 17 loss was observed frequently in serous tumors (49%), was less common in endometrioid tumors (15%), and was rare in mucinous tumors (4%) (P = .01 and P = .0002, respectively). Our findings support the concept that the histological subtypes of epithelial ovarian cancer may be the result of different molecular genetic events.
Insights
Loss of chromosome 17 is common in epithelial ovarian tumors, particularly serous types. This genetic event may explain different ovarian cancer subtypes and their aggressiveness.
Area of Science:
- Oncology
- Genetics
- Gynecologic Pathology
Background:
- Epithelial ovarian tumors are common in adult women, presenting diverse histological patterns and aggressiveness.
- Molecular genetic studies indicate loss of heterozygosity (LOH) on chromosome 17 is frequent in epithelial ovarian cancer, suggesting tumor suppressor gene inactivation.
Purpose of the Study:
- To investigate the frequency and patterns of chromosome 17 LOH in sporadic epithelial ovarian tumors.
- To determine if LOH on chromosome 17 correlates with specific histological subtypes of ovarian cancer.
Main Methods:
- Analysis of 87 sporadic epithelial ovarian tumors of varying grades and histological types.
- Examination of LOH at 16 specific loci on chromosome 17.
Main Results:
- Loss of heterozygosity (LOH) for chromosome 17 was observed in 35% of the epithelial ovarian tumors studied.
- A significant majority (84%) of tumors with LOH showed loss across all informative markers, suggesting whole chromosome loss.
- Chromosome 17 loss was significantly more frequent in serous tumors (49%) compared to endometrioid (15%) and mucinous (4%) subtypes.
Conclusions:
- The findings support the hypothesis that distinct molecular genetic events, including chromosome 17 loss, underlie the different histological subtypes of epithelial ovarian cancer.
- Chromosome 17 alterations are a key feature in the pathogenesis of specific epithelial ovarian cancer subtypes.