MicroRNAs as markers of progression in cervical cancer: a systematic review.

BACKGROUND: Invasive cervical cancer (ICC) is caused by high-risk human papillomavirus types (HR-HPVs) and is usually preceded by a long phase of intraepithelial neoplasia (CIN). Before invasion, (epi) genetic changes, potentially applicable as molecular markers within cervical screening, occur in HPV host cells. Epigenetic alterations, such as dysregulation of microRNA (miRNA) expression, are frequently observed in ICC. The mechanisms and role of miRNA dysregulation in cervical carcinogenesis are still largely unknown. METHODS: We provide an overview of the studies investigating miRNA expression in relation to ICC progression, highlighting their common outcomes and their weaknesses/strengths. To achieve this, we systematically searched through Pubmed database all articles between January 2010 and December 2017. RESULTS: From the 24 studies retrieved, miR-29a and miR-21 are the most frequently down- and up-regulated in ICC progression, respectively. Microarray-based studies show a small overlap, with miR-10a, miR-20b, miR-9, miR-16 and miR-106 found repeatedly dysregulated. miR-34a, miR-125 and miR-375 were also found dysregulated in cervical exfoliated cells in relation to cancer progression. CONCLUSIONS: The pivotal role of miRNAs in ICC progression and initial development is becoming more and more relevant. Available studies are essentially based on convenience material, entailing possible selection bias, and frequently of small size: all these points still represent a limitation to a wide comprehension of miRNAs relevant for ICC. The targeted approach instead of a genome-wide investigation still precludes the identification of all the relevant miRNAs in the process. The implementation of deep sequencing on large scale population-based studies will help to discover and validate the relation between altered miRNA expression and CC progression for the identification of biomarkers. Optimally, once explored on a miRNome scale, small specific miRNA signatures maybe used in the context of screening.

Prevalence of cervical colonization by Ureaplasma parvum, Ureaplasma urealyticum, Mycoplasma hominis and Mycoplasma genitalium in childbearing age women by a commercially available multiplex real-time PCR: An Italian observational multicentre study.

BACKGROUND: Mycoplasmas are frequently isolated from the genital tract. New molecular PCR-based methods for the detection of mycoplasmas can better define the real epidemiology of these microorganisms. The aim of this study was to evaluate the prevalence of mycoplasmas in a population of childbearing age women by means of PCR. METHODS: This 21-month multicentre observational study was conducted at four Italian clinical microbiology laboratories. Women reporting symptoms of vaginitis/cervicitis, or with history of infertility, pregnancy, miscarriage or preterm birth were included. Detection of Ureaplasma parvum, Ureaplasma urealyticum, Mycoplasma hominis, Mycoplasma genitalium was performed from cervical swabs by means of a commercially available multiplex real-time PCR. RESULTS: a total of 1761 women fulfilled the inclusion criteria and were included in the study. The overall prevalence was: U. parvum 38.3%, U. urealyticum 9%, M. hominis 8.6% and M. genitalium 0.6%. The proportion of foreign patients positive for U. parvum was significantly higher compared to Italian patients (37% vs 30.1%, p = 0.007) and also for overall mycoplasma colonization (53.4% vs 45.8%, p = 0.011). The number of symptomatic patients positive for M. hominis was significantly higher than that of negative controls (2.9% vs 1%, p = 0.036). A significant positive trend in mycoplasma colonization was found in relation to the pregnancy week for U. urealyticum (p = 0.015), M. hominis (p = 0.044) and for overall mycoplasma colonization (p = 0.002). CONCLUSION: multiplex RT-PCR can be a valuable tool to evaluate the real epidemiology of cervical mycoplasma colonization.