Human papillomavirus genotype-specific risk in cervical carcinogenesis.

OBJECTIVE: To evaluate the risk of genotype-specific human papillomavirus (HPV) infections for the spectrum of cervical carcinogenesis and the distribution of HPV types according to age and different cervical lesions. METHODS: This study included HPV-positive women who underwent cervical biopsy at the Cheil General Hospital & Women's Healthcare Center between July 1, 2011 and December 31, 2017. HPV genotyping was conducted using a Cheil HPV DNA chip kit. RESULTS: The study sample consisted of 400 normal, 399 cervical intraepithelial neoplasia (CIN) 1, 400 CIN 2, 400 CIN 3, and 389 cervical cancer cases. HPV 16 was the most common type found with a prevalence of 9.5% in normal, 6.8% in CIN 1, 15.0% in CIN 2, 44.5% in CIN 3, and 64.3% in cervical cancer. The most common HPV types were 16, 52, 58, 53, 51, 56, 68, and 18 in all study samples. HPV 16, 31, 33, and 58 were more common in CIN 2/3 and cancer, and HPV 39, 51, 53, 56, 66, and 68 were more common in CIN 1 and normal cases (p<0.001). In CIN 3 and cervical cancer, HPV 16 was the most common type in all age groups. HPV 52 was the most common type in CIN 2 (all age groups) and in CIN 1/normal (age ≤30 years) cases. Among the high-risk HPV types, 16, 31, 33, 52, and 58 showed significant risk for high-grade disease. CONCLUSIONS: HPV 16, 31, 33, 52, and 58 showed the significant risk of high-grade disease for cervical carcinogenesis.

Method to minimize ozone effect on Cy5 fluorescent intensity in DNA microarrays.

Cyanine 5 (Cy5) is an established fluorescent dye in microarray analysis. It is degraded rapidly when exposed to atmospheric ozone during post-hybridization washes, which leads to loss of fluorescent intensity. To minimize this undesirable effect, we coated microarray slides with sodium dodecyl sulfate (SDS) solution at post-hybridization washes. The fluorescent intensities on coated slides were more stable than those on uncoated slide. We also performed the microarrays with SDS solution for a year to check the solution's effectiveness along with seasonal changes of atmospheric ozone level. Consistent results in microarray analysis were obtained using Cy5 dye under atmospheric ozone.

Combined SYBR Green real-time polymerase chain reaction and microarray method for the simultaneous determination of human papillomavirus loads and genotypes.

OBJECTIVE: The aim of this study was to describe the principle of the Cheil HPV DNA Chip assay and evaluate its accuracy. In order to quantify the human papillomavirus (HPV) load and identify HPV genotypes simultaneously, this assay combined the two methods: SYBR Green quantitative real-time polymerase chain reaction (PCR) and DNA microarray. METHODS: We designed novel consensus primer sets that target the conserved region of the HPV L1 gene for quantifying and detecting a broad range of HPV types by quantitative real-time PCR. Subsequently, using the PCR products, DNA microarray was performed with 36 HPV type-specific probes. To validate this method, direct sequencing and correlation analysis among HPV genotype, viral load, and cytological abnormality was performed by Cohen's kappa values, two-sided McNemar chi-square test, Kruskal-Wallis test, and odds ratios. RESULTS: The kappa value of the Cheil HPV DNA Chip was 0.963 (95% confidence interval, 0.919 to 0.98), which was significantly higher than the value of 0.527 (95% confidence interval, 0.447 to 0.59) obtained using a conventional HPV DNA Chip. HPV16 (χ2=62.28, P<0.01), HPV33 (χ2=7.18, P<0.01), and HPV58 (χ2=9.52, P<0.01), which are classified as high-risk HPVs, were detected at significant levels in samples with high-grade lesions. And viral loads tended to be higher in groups with high odds ratios. CONCLUSION: The Cheil HPV DNA Chip is an effective diagnostic assay for simultaneously detecting HPV genotypes and loads in cervical samples.

Development of reference materials to detect 15 different human papillomavirus genotypes.

Accurate human papillomavirus (HPV) typing is essential for evaluating and monitoring HPV vaccines in cervical cancer screening and in epidemiological surveys. In our country, different HPV DNA detection and genotyping methodologies have been established for diagnosing and monitoring HPV-related disease in clinical practice and for research. However, there is a lack of reference materials to standardize the methods for HPV detection and genotyping. In this study, we constructed candidate reference materials comprising 15 targets (13 types of high-risk HPV, two types of low-risk HPV). We evaluated whether the candidate reference materials could be used as the reference for HPV detection and genotyping using quantitative real-time polymerase chain reaction. Standard curves for the wide linear range (10(1)-10(6)copies/µL) produced high correlation regression coefficient R(2) of 0.99. The reaction efficiencies were 96.3% to 101.2% for the standard curves, indicating highly efficient reactions. Specific genotypes were detected in single or multiple mixed samples. Our results suggest that these reference materials may provide useful standards for standardizing quality assurance for different HPV-typing assays and for proficiency testing in diagnostic laboratories.

A convenient preparation of a disaccharide motif and its role in the cytotoxicity of the triterpenoid saponin, alpha-hederin.

The sugar structures of triterpenoid saponins, such as alpha-hederin, are intimately associated with their antitumor activities and other biological activities. The alpha-L: -rhamnopyranosyl-(1-->2)-alpha-L: -arabinopyranoside group of alpha-hederin alters the cytotoxicity of its aglycon, hederagenin. This study explored the role of this saccharide unit in the cytotoxic effect of alpha-hederin and the possibility of its use as a carrier moiety in prodrugs of anticancer agents. A new convenient and practical procedure for the preparation of 4-methoxybenzoyl-2,3,4-tri-O-benzoyl-alpha-L: -rhamnopyranosyl-(1-->2)-3,4-O-dibenzoyl-beta-L: -arabinopyranoside (2) from 4-methoxybenzoyl-beta-L: -arabinopyranoside was accomplished using four steps with an overall yield of 63%. The use of BF(3)-OEt(2) as a catalyst in the glycosylation step in this procedure had a large advantage over the TMSOTf catalyst used in the usual method. Moreover, the key intermediate obtained in this procedure, 4-methoxybenzoyl-2,3,4-tri-O-benzoyl-alpha-L: -rhamnopyranosyl-(1-->2)-alpha-L: -arabinopyranoside (7), was selectively transformed to 4-methoxybenzoyl-2,3,4-tri-O-benzoyl-alpha-L: -rhamnopyranosyl-(1-->2)-4-O-acetyl-alpha-L: -arabinopyranoside (9) and 4-methoxybenzoyl-2,3,4-tri-O-benzoyl-alpha-L: -rhamnopyranosyl-(1-->2)-3-O-benzoyl-beta-L: -arabinopyranoside (10). These derivatives did not show any cytotoxicity against human cancer cell lines. Thus the 3-O-alpha-L: -rhamnopyranosyl-(1-->2)-alpha-L: -arabinopyranoside could be used as a nontoxic carrier moiety to enhance the activity of anticancer drugs.

Phytohormone abscisic acid control RNA-dependent RNA polymerase 6 gene expression and post-transcriptional gene silencing in rice cells.

RNA-dependent RNA polymerase 6 (RDR6) catalyses dsRNA synthesis for post-transcriptional gene silencing (PTGS)-associated amplification and the generation of endogeneous siRNAs involved in developmental determinations or stress responses. The functional importance of RDR6 in PTGS led us to examine its connection to the cellular regulatory network by analyzing the hormonal responses of RDR6 gene expression in a cultured cell system. Delivery of dsRNA, prepared in vitro, into cultured rice (Oryza sativa cv. Japonica Dongjin) cells successfully silenced the target isocitrate lyase (ICL) transcripts. Silencing was transient in the absence of abscisic acid (ABA), while it became persistent in the presence of ABA in growth medium. A transcription assay of the OsRDR6 promoter showed that it was positively regulated by ABA. OsRDR6-dependent siRNA(ICL) generation was also significantly up-regulated by ABA. The results showed that, among the five rice OsRDR isogenes, only OsRDR6 was responsible for the observed ABA-mediated amplification and silencing of ICL transcripts. We propose that ABA modulates PTGS through the transcriptional control of the OsRDR6 gene.

Facile synthesis of trisaccharide moiety corresponding to antitumor activity in triterpenoid saponins isolated from Pullsatilla roots.

A trisaccharide found in triterpenoid saponins isolated from Pullsatilla roots appears as an important promoiety for the enhancement of anticancer activity of their aglycones. Thus a facile synthetic method for a trisaccharide moiety, allyl-2,3,4-tri-O-benzoyl-alpha-L-rhamnopyranosyl-(1-->2)-[2,3,4,6-tetra-O-benzoyl-beta-D-glucopyranosyl-(1-->4)]-3-O-benzoyl-beta-L-arabinopyranoside (3), has been firstly developed through the regio- and stereoselective glycosylations from arabinose in total 16% yield via route 2 (eight steps). In this synthetic procedure, the protection of anomeric -OH of L-arabinose with equatorially oriented allyl group unlike with the axial 4-methoxybenzyl protecting group well promoted glycosyl bond formation between alpha-L-rhamnopyranosyl trichloroacetimidate and 2-OH of arabinose. As expected, the synthesized trisaccharide moiety 3 has no cytotoxicity (ED50: >100 microM) against three human cancer cell lines (A-549, SK-OV-3, and SK-MEL-2), respectively.

Evaluation of anticancer activity of 4-vinyl-1-arylsulfonylimidazolidinones.

To continue exploration of structure activity relationship of novel 1-(indoline-5-sulfonyl)-4-phenylimidazolidinones (1) reported as anticancer agent with broad spectrum, three 1-(arylsulfonyl)-4-vinylimidazolidinones (2) were synthesized from methyl serinate (3) in 8 steps. Reaction of intermediate 2-phenoxycarbonylaminobut-3-enyl p-toluenesulfonate (10) with arylsulfonamide in the presence of potassium carbonate produced corresponding 2 and N-(4-vinyloxazolidin-2-yl)arylsulfonamide 11 in approximately equal ratio. This reaction is believed to undergo through urea intermediate 16 as shown in scheme 3. 1-Arylsufonyl-4-vinylimidazolidinones 2 show much reduced activity against human colon carcinoma (Colo205), human chronic myelogenous leukemia (K562), and human ovarian adenocarcinoma (SK-OV-3) and compatible activity against human lung carcinoma (A549) compared to 1. Therefore phenyl at 4-position should be the optimum planar motif for the activity of 1.