A STUDY TO ANALYZE CERVICAL RIPENING FACTORS WITH SCRAPED ENDOCERVICAL CELLS

Abstract

The biochemical changes in the uterine cervices during pregnancy in real time are not known. To develop a new method for evaluating the change in mRNA levels in the uterine cervix during pregnancy, we performed several basic studies for endocervical cell sampling and RNAextraction from the endocervical cells. The candidates for this research were healthy pregnant women without labor. Endocervical cells were collected with a Dacron swab or a Cytobrush^® instrument. To determine the efficiency of sample collection, we evaluated samples by the Papanicolaou smear method. The efficiency of RNA extraction was also examined. Synthetic oligonucleotide designed to specifically target cyclooxygenase 2 (Cox-2), matrix metalloproteinase-3 (MMP-3), tissue inhibitors of metalloproteinase (TIMP-1), and inducible nitric oxide synthase (iNOS) were used in RT-PCR. The expression of Cox-2 mRNA in endocervical cells obtained from normal pregnant women (9 in the second trimester and 8 in the third trimester) were measured by real-time PCR. The Cytobrush collection method made it possible to obtain RNA from endocervical cells with satisfactory quantity and quality. The mRNA of Cox-2, TIMP-1, iNOS, and MMP-3 cDNAs were successfully amplified. Expression of Cox-2 mRNA was significantly higher in term cells (0.10±0.06 copy/β-actin copy) than in second trimester pregnancy cells (0.03±0.04 copy/β -actin copy) (p<0.05) . Collection of endocervical cells and quantitative analysis of mRNA extracted from these cells were possible by the brushing method. These results suggest that this simple, noninvasive method may be useful in a clinical setting to analyze cervical ripening and predict preterm delivery.