Infection of cervical epithelium with high-risk human papilloma virus (hrHPV) might result in productive or transforming cervical intraepithelial neoplasia (CIN) lesions, the morphology of which can ...overlap. In transforming CIN lesions, aberrations in host cell genes accumulate over time, which is necessary for the ultimate progression to cancer. On the basis of (epi)genetic changes, early and advanced transforming CIN lesions can be distinguished. This paves the way for new molecular tools for cervical screening, diagnosis and management of cervical cancer precursor lesions.
Celotno besedilo
Dostopno za:
DOBA, IJS, IZUM, KILJ, NUK, PILJ, PNG, SAZU, UILJ, UKNU, UL, UM, UPUK
A substantial number of microRNAs (miRNAs) is subject to epigenetic silencing in cancer. Although epigenetic silencing of tumour suppressor genes is an important feature of cervical cancer, little is ...known about epigenetic silencing of miRNAs. Since DNA methylation-based silencing of hsa-miR-124 occurs in various human cancers, we studied the frequency and functional effects of hsa-miR-124 methylation in cervical carcinogenesis.
Quantitative MSP analysis of all 3 loci encoding the mature hsa-miR-124 (hsa-miR-124-1/-2/-3) showed methylation in cervical cancer cell lines SiHa, CaSki and HeLa as well as in late passages of human papillomavirus (HPV) type 16 or 18 immortalised keratinocytes. Treatment of SiHa cells with a demethylating agent reduced hsa-miR-124 methylation levels and induced hsa-miR-124 expression. In HPV-immortalised keratinocytes increased methylation levels were related to reduced hsa-miR-124 expression and higher mRNA expression of IGFBP7, a potential hsa-miR-124 target gene. Ectopic hsa-miR-124 expression in SiHa and CaSki cells decreased proliferation rates and migratory capacity. Combined hsa-miR-124-1 and/or hsa-miR-124-2 methylation analysis of 139 cervical tissue specimens showed an increasing methylation frequency from 0% in normal tissues up to 93% in cervical carcinomas. Increased methylation levels of hsa-miR-124-1 and hsa-miR-124-2 were significantly correlated with reduced hsa-miR-124 expression in cervical tissue specimens. Combined hsa-miR-124-1 and/or hsa-miR-124-2 methylation analysis of 43 cervical scrapes of high-risk HPV positive women was predictive of underlying high-grade lesions.
DNA methylation-based silencing of hsa-miR-124 is functionally involved in cervical carcinogenesis and may provide a valuable marker for improved detection of cervical cancer and its high-grade precursor lesions.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
Human papillomavirus (HPV)-related screening technologies and HPV vaccination offer enormous potential for cancer prevention, notably prevention of cervical cancer. The effectiveness of these ...approaches is, however, suboptimal owing to limited implementation of screening programmes and restricted indications for HPV vaccination. Trials of HPV vaccination in women aged up to 55 years have shown almost 90% protection from cervical precancer caused by HPV16/18 among HPV16/18-DNA-negative women. We propose extending routine vaccination programmes to women of up to 30 years of age (and to the 45-50-year age groups in some settings), paired with at least one HPV-screening test at age 30 years or older. Expanding the indications for HPV vaccination and much greater use of HPV testing in screening programmes has the potential to accelerate the decline in cervical cancer incidence. Such a combined protocol would represent an attractive approach for many health-care systems, in particular, countries in Central and Eastern Europe, Latin America, Asia, and some more-developed parts of Africa. The role of vaccination in women aged >30 years and the optimal number of HPV-screening tests required in vaccinated women remain important research issues. Cost-effectiveness models will help determine the optimal combination of HPV vaccination and screening in public health programmes, and to estimate the effects of such approaches in different populations.
Electron transfer (ET) from donor to acceptor is often mediated by nuclear-electronic (vibronic) interactions in molecular bridges. Using an ultrafast electronic-vibrationalvibrational ...pulse-sequence, we demonstrate how the outcome of light-induced ET can be radically altered by mode-specific infrared (IR) excitation of vibrations that are coupled to the ET pathway. Picosecond narrow-band IR excitation of high-frequency bridge vibrations in an electronically excited covalent trans-acetylide platinum(II) donor-bridge-acceptor system in solution alters both the dynamics and the yields of competing ET pathways, completely switching a charge separation pathway off. These results offer a step toward quantum control of chemical reactivity by IR excitation.
This review elaborates on the accuracy and feasibility of human papillomavirus (HPV) self‐sampling, i.e., offering self‐sampling of (cervico‐)vaginal cell material by women themselves in nonclinical ...settings for high‐risk HPV (hrHPV) detection in the laboratory, for cervical screening. To that end a bibliographic database search (PubMed) was performed to identify studies (published between January 1992 and January 2012) that compared clinical accuracy of HPV testing on self‐sampled material with that of cytology or HPV testing on clinician‐taken samples, and studies comparing response to offering HPV self‐sampling with a recall invitation. Overall, hrHPV testing on self‐samples appeared to be at least as, if not more, sensitive for cervical intraepithelial neoplasia grade 2 or worse (CIN2+) as cytology on clinician‐obtained cervical samples, though often less specific. In most studies, hrHPV testing on self‐ and clinician‐sampled specimens is similarly accurate with respect to CIN2+ detection. Variations in clinical performance likely reflect the use of different combinations of collection devices and HPV tests. Because it is known that underscreened women are at increased risk of cervical cancer, targeting non‐attendees of the screening program could improve the effectiveness of cervical screening. In developed countries offering self‐sampling has shown to be superior to a recall invitation for cytology in re‐attracting original non‐attendees into the screening program. Additionally, self‐testing has shown to facilitate access to cervical screening for women in low resource areas. This updated review of the literature suggests that HPV self‐sampling could be an additional strategy that can improve screening performance compared to current cytology‐based call‐recall programs.
Human papillomavirus (HPV) infection has been etiologically linked to oropharyngeal squamous cell carcinoma (OPSCC). The prevalence of HPV‐positive OPSCC varies between studies, ranging from 20 to ...90%. This may be related to the lack of a standardized HPV detection assay as well as to the time period in which HPV prevalence is investigated, as rising incidence rates are reported over the last decades. Here, we validated our previously defined test algorithm for HPV detection in formalin‐fixed paraffin‐embedded (FFPE) tumor specimen consisting of p16INK4A immunostaining followed by high‐risk HPV DNA detection by GP5+/6+ PCR on the positive cases (Smeets et al., Int J Cancer 2007;121:2465–72). In addition, we analyzed HPV prevalence rates in OPSCCs in the years 1990–2010. The test algorithm was validated on a consecutive series of 86 OPSCCs collected during 2008–2011, of which both fresh frozen and FFPE samples were available. We performed HPV‐E6 RT‐PCR on the frozen samples as gold standard and applied the algorithm to the corresponding FFPE samples. The test algorithm showed an accuracy of 98%. Using the validated algorithm, we determined the presence of an oncogenic HPV infection in 240 OPSCCs of patients diagnosed in the years 1990–2010 at our center. A significant increase in the proportion of HPV‐positive samples was observed, from 5.1% in 1990 to 29.0% in 2010 (p = 0.001). In conclusion, we confirmed the accuracy of the test algorithm for HPV detection in FFPE tumor specimen and we found a significant increase in the prevalence of HPV in OPSCC over the last two decades at our center.
What's new?
We validated our previously defined test algorithm for human papillomavirus (HPV) detection in formalin‐fixed paraffin‐embedded tumor specimen. The test algorithm showed an accuracy of 98%, and using this validated algorithm we found a significant increase in the proportion of HPV‐positive oropharyngeal squamous cell carcinomas (OPSCCs) from 5.1% in 1990 to 29.0 % in 2010. A reliable HPV detection assay is urgently awaited and the rapidly rising proportion of HPV‐induced OPSCC in the Netherlands is worrying
Summary Background 15% of women treated for high-grade cervical intraepithelial neoplasia (CIN grade 2 or 3) develop residual or recurrent CIN grade 2 or 3 or cervical cancer, most of which are ...diagnosed within 2 years of treatment. To gain more insight into the long-term predictive value of different post-treatment strategies, we assessed the long-term cumulative risk of post-treatment CIN grade 2 or 3 or cancer and different follow-up algorithms to identify women at risk of residual or recurrent disease. Methods Women who were included in three studies in the Netherlands and who were treated for CIN grade 2 or 3 between July, 1988, and November, 2004, were followed up by cytology and testing for high-risk human papillomavirus (hrHPV) at 6, 12, and 24 months after treatment, and subsequently received cytological screening every 5 years. The primary endpoint was the cumulative risk of post-treatment CIN grade 2 or higher by December, 2009. We also assessed the cumulative risk of CIN grade 2 or higher in women with three consecutive negative cytological smears and women with negative co-testing with cytology and hrHPV at months 6 and 24. This study is registered in the Dutch trial register, NTR1468. Findings 435 women were included, 76 (17%) of whom developed post-treatment CIN grade 2 or higher, of which 39 were CIN grade 3 or higher. The 5-year risk of developing post-treatment CIN grade 2 or higher was 16·5% (95% CI 13·0–20·7) and the 10-year risk was 18·3% (13·8–24·0). The 5-year risk of developing post-treatment CIN grade 3 or higher was 8·6% (95% CI 6·0–12·1) and the 10-year risk was 9·2% (5·8–14·2). Women with three consecutive negative cytological smears had a CIN grade 2 or higher risk of 2·9% (95% CI 1·2–7·1) in the next 5 years and of 5·2% (2·1–12·4) in the next 10 years. The 5-year risk of CIN grade 3 or higher was 0·7% (95% CI 0·0–3·9) and the 10-year risk was 0·7% (0·0–6·3). Women with negative results for co-testing had a 5-year risk of CIN grade 2 or higher of 1·0% (95% CI 0·2–4·6) and a 10-year risk of 3·6% (1·1–10·7). The 5-year risk of CIN grade 3 or higher was 0·0% (95% CI 0·0–3·0) and the 10-year risk was 0·0% (0·0–5·3). Interpretation The 5-year risk of post-treatment CIN grade 2 or higher in women with three consecutive negative cytological smears or negative co-testing for cytology and hrHPV at 6 and 24 months was similar to that of women with normal cytology in population-based screening and therefore justifies their return to regular screening. Funding VU University Medical Center, Erasmus University Medical Center, Netherlands.
Hematite microparticles are becoming increasingly important components in the soft matter field. The remarkable combination of magnetic and photocatalytic properties that characterize them, coupled ...with the variety of uniform and monodisperse shapes that they can be synthesized in, makes them a one of a kind colloidal model system. Thanks to these properties, hematite microparticles have been recently applied in several important soft matter applications, spanning from novel colloidal building blocks for self-assembly to necessary tools to investigate and understand fundamental problems. In this review article we provide a detailed overview of the traditional methods available for the preparation of hematite microparticles of different shapes, devoting special attention on some of the most common hiccups that could hider a successful synthesis. We furthermore review the particles' most important physico-chemical properties and their most relevant applications in the soft matter field.
Hematite microparticles are becoming increasingly important components in the soft matter field. This review summarizes methods for their preparation, and gives an overview of their physico-chemical properties and current applications.
Little is known about the alterations in microRNA (miRNA) expression patterns during the consecutive stages of cervical cancer development and their association with chromosomal instability. In this ...study, miRNA expression in normal cervical squamous epithelium, high-grade precancerous lesions (cervical intraepithelial neoplasia (CIN2-3)), squamous cell carcinomas (SCCs) and adenocarcinomas (AdCAs) was integrated with previously generated chromosomal profiles of the same samples. Significantly differential expression during the consecutive stages of cervical SCC development was observed for 106 miRNAs. Of these differentially expressed miRNAs, 27 showed early transiently altered expression in CIN2-3 lesions only, 46 miRNAs showed late altered expression in SCCs only and 33 showed continuously altered expression in both CIN2-3 and SCCs. Altered expression of five significantly differentially expressed miRNAs, hsa-miR-9 (1q23.2), hsa-miR-15b (3q25.32), hsa-miR-28-5p (3q27.3), hsa-miR-100 and hsa-miR-125b (both 11q24.1), was directly linked to frequent chromosomal alterations. Functional analyses were performed for hsa-miR-9, representing a potential oncogene with increased expression linked to a chromosomal gain of 1q. Hsa-miR-9 overexpression was found to increase cell viability, anchorage-independent growth and migration in vitro. Upon organic raft culturing, hsa-miR-9 hampered differentiation and induced proliferation in all strata of the epithelial layer. These findings support a potential oncogenic function of hsa-miR-9 in cervical cancer. In summary, differential expression of 106 miRNAs, partly associated with chromosomal alterations, was observed during cervical SCC development. Altered expression of hsa-miR-9 associated with a chromosomal gain of chromosome 1q was shown to be functionally relevant, underlining the importance of deregulated miRNA expression in cervical carcinogenesis.
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