Fragmentation of cell-free fetal DNA in plasma and urine of pregnant women.

OBJECTIVES: We assessed the effect of freezing on fragmentation of fetal DNA in maternal plasma and differences in DNA fragmentation between plasma and urine from pregnant women. METHODS: 1. We prepared seven kinds of real-time PCR assays to amplify different-sized amplicons targeting the SRY gene. Fragmentation of fetal DNA in maternal plasma was compared between new (n=10) and 4-year-old samples (n=10). 2. To investigate differences in fragmentation of fetal DNA between plasma and urine from pregnant women, we amplified three different-sized amplicons and compared DNA fragmentation between plasma and urine (n=7). RESULTS: 1. Relative concentrations of fetal DNA compared to a 63-bp amplicon in new samples were 53.1, 42.0, 9.2 and 2.0% (median) for PCR amplicons of 107, 137, 193 and 313 bp, respectively. Concentrations in 4-year-old samples were 70.4, 40.9, 11.9 and 2.3%, respectively. 2. Although fetal DNA in urine was not detected for 107- and 137-bp amplicons of the SRY sequence, fetal DNA using a 63-bp amplicon was detectable in five of seven cases (71.4%). CONCLUSION: Cell-free fetal DNA in maternal plasma is stable under cryopreservation at -20 degrees C for at least 4 years. Approximately, 60% of fetal DNA in maternal plasma was fragmented to <100-bp long, and fetal DNA in urine was further fragmented. Maternal urine may be usable for detection of fetal DNA, although smaller target size is more important for PCR amplification of fetal DNA in urine than in the analysis of plasma from pregnant women.

The influence of inflammatory cytokines on estrogen production and cell proliferation in human breast cancer cells.

Estrogens play important roles in the development of breast cancer. Inflammatory cytokines such as interleukin-6 (IL-6) and interleukin-1 beta (IL-1 beta) exist at high concentrations in breast cancer tissue. Although these cytokines are thought to exert some effect on cancer growth, their precise mechanism is still unclear. In the present study, we investigated the effects of inflammatory cytokines on aromatase (Arom) and steroid sulfatase (STS), which are estrogen-producing enzymes, and cell proliferation using human breast cancer cell lines (SK-BR-3, MCF-7). IL-6 and IL-1 beta stimulated the activity of Arom and STS. Estrone sulfate (E1-S) had a stimulus effect on cell proliferation of MCF-7. Although IL-6 did not show significant effect on cell proliferation, cell proliferation was significantly increased when IL-6 and E1-S were simultaneously added to the incubation medium. This cell proliferative effect was apparently stronger than the addition of E1-S alone. Addition of IL-1 beta in the presence of E1-S also significantly enhanced cell proliferation though IL-1 beta alone did not show any effect. These results led us to the hypothesis that inflammatory cytokines such as IL-6 and IL-1 beta regulate proliferation of breast cancer cells through estrogen production by steroid-catalyzing enzymes in the tissue.