Objective: Investigate the frequency of loss of heterozygosity (LOH) at chromosome arm the short arm chromosome 3p14, 25 in the serum DNA from ovarian cancer and its clinical application.
Methods: Thirty-eight ovarian cancer serum samples with 18 corresponding tumor tissues and 8 benign ovarian tumors were obtained, and DNA samples extracted from serum and tissue were examined for 3p14, 25 LOH by using of polymerase chain reaction with four polymorphic microsatellite markers (D3S1029, D3S1228, D3S1300, D3S1481).
Results: Matched serum and tissue DNAs from 18 ovarian cancer patients showed significant concordance of 3p14, 25 LOH (P < 0.05). 3p14, 25 LOH in at least one of four loci occurred in 29 out of 38 (76%) serum samples, while 17 serum samples (45%) exhibited LOH at more than one locus. According to International Federation of Gynecology and Obstetrics (FIGO) staging, there was a trend that the rate of LOH was higher in advanced stages, and the frequency of loss in stage II, III, IV was 2/4, 78%, 8/9 respectively. It was also found that the number of microsatellite markers with 3p14, 25 LOH was increased with tumor progressed. No significant association of pathological types with LOH in serum DNA could be demonstrated except at locus D3S1029.
Conclusions: Since the strong correlation of 3p14, 25 LOH between serum DNA and tumor tissue DNA, as well as the frequency of 3p14, 25 LOH associated with malignancy of ovarian cancer, it is suggested that detection of serum DNA 3p14, 25 LOH may be used as a molecular marker for staging and monitoring human ovarian cancer.