The separation of exfoliated cells from the brushes used during cervico-vaginal smears is difficult, a problem which may affect the quality of ribonucleic acid (RNA) extracted. We compared the results of RNA extraction from cervicovaginal cytology samples according to the type of tubes, preservative solutions, and storage temperature. The samples included exfoliated cervico-vaginal cytological specimens from patients with human papilloma virus 16, positive for cervical intraepithelial neoplasia or cervical cancer. Exfoliated cells were obtained by shaking a brush in a conventional rigid vial tube or squeezing the brush in a soft vial tube. RNA quantity and quality were compared between the two tubes. The concentration and purity of RNA (A260/A280 and A260/A230 ratios) was compared amongst five groups: Group 1, standard frozen storage; Group 2-4, RNA stabilization reagents with room temperature [RNAlater RNA Stabilization Reagent, RNAprotect cell Reagent and AllProtect Tissue Reagent]; and Group 5, Surepath Preservative fluid. To demonstrate the utility of the extracted RNA for PCR-based cDNA synthesis, GAPDH and E6 were targeted and gel band densities of GAPDH and E6 were measured. The median RNA concentration was significantly higher in the soft tubes compared with the rigid tubes (100.2 vs. 7.1 ng/μL, p = 0.0209). The purity of the RNA was higher in soft vial tubes than in rigid vials, as measured by A260/280 and A260/ 230 ratios. The RNA concentration, purity, and GAPDH density of groups 1, 2 and 3 were significantly higher than those of groups 4 and 5. Moreover, E6 density of group 1 and 2 was significantly higher than that of group 3, 4 and 5. The use of soft tubes enhanced the mRNA quantity and quality in cervico-vaginal cytology. The products of mRNA extraction using RNAlater RNA Stabilization Reagent and RNAprotect Cell Reagent at room temperature were comparable to those obtained by conventional frozen storage. Our protocol improved the yield and quality of RNA and might produce better results for molecular analysis in cervico-vaginal cytology.

One-step RT-LAMP is a potentially useful and complementary tool that is fast and reasonably sensitive. In addition, one-step RT-LAMP could be useful in environments lacking specialized equipment or expertise.

ObjectiveThe aim of this study was to detect high risk human papillomavirus in cervical cancer with a pretreatment negative high risk human papillomavirus DNA genotype test and to evaluate clinicopathologic characteristics and survival outcomes according to high risk human papillomavirus status.MethodsWe investigated high risk human papillomavirus status in surgical specimens from 30 cases of cervical cancer using polymerase chain reaction. Polymerase chain reaction primers were set to detect the presence of the common L1 and E7 regions of human papillomavirus types 16, 18, 31, 33, 45, 52, and 58. We analyzed the following clinicopathologic parameters to evaluate their relationships with high risk human papillomavirus status: age, histology, stage, tumor size, invasion depth, lymphovascular invasion, and recurrent status.ResultsAmong 30 cases with a pretreatment negative DNA genotype test, high risk human papillomavirus was detected in 12 (40.0%), whereas 18 (60.0%) were negatives. Of 12 high risk human papillomavirus positive cases, 10 (33.3%) were positive for the L1 region, 6 (20.0%) of the 7 types were positive for the E7 region, and 4 (13.1%) were positive for both L1 and E7 regions. According to a multiple logistic regression model, tumor size (odds ratio 7.80; 95% confidence interval 1.476 to 41.216; P=0.0097) and stage (odds ratio 7.00; 95% confidence interval 1.293 to 37.910; P=0.0173) were associated with negative high risk human papillomavirus DNA status. Kaplan–Meier survival plots showed that negative high risk human papillomavirus status was associated with worse disease free survival in contrast with positive high risk human papillomavirus status (P=0.0392).ConclusionsNegative high risk human papillomavirus was found in 60% of cervical cancers with a pretreatment negative DNA genotype test. Moreover, the negative high risk human papillomavirus group was associated with worse survival outcome.

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These results demonstrate that despite the lower purity and integrity of RNA, our RNA preparation protocol is simple and rapid and shows reasonable performance in RT-LAMP.