miRNA expression profiling of 51 human breast cancer cell lines reveals subtype and driver mutation-specific miRNAs

INTRODUCTION: Breast cancer is a genetically and phenotypically complex disease. To understand the role of miRNAs in this molecular complexity, we performed miRNA expression analysis in a cohort of molecularly well-characterized human breast cancer cell lines to identify miRNAs associated with the most common molecular subtypes and the most frequent genetic aberrations. METHODS: Using a microarray carrying LNA™ modified oligonucleotide capture probes), expression levels of 725 human miRNAs were measured in 51 breast cancer cell lines. Differential miRNA expression was explored by unsupervised cluster analysis and was then associated with the molecular subtypes and genetic aberrations commonly present in breast cancer. RESULTS: Unsupervised cluster analysis using the most variably expressed miRNAs divided the 51 breast cancer cell lines into a major and a minor cluster predominantly mirroring the luminal and basal intrinsic subdivision of breast cancer cell lines. One hundred and thirteen miRNAs were differentially expressed between these two main clusters. Forty miRNAs were differentially expressed between basal-like and normal-like/claudin-low cell lines. Within the luminal-group, 39 miRNAs were associated with ERBB2 overexpression and 24 with E-cadherin gene mutations, which are frequent in this subtype of breast cancer cell lines. In contrast, 31 miRNAs were associated with E-cadherin promoter hypermethylation, which, contrary to E-cadherin mutation, is exclusively observed in breast cancer cell lines that are not of luminal origin. Thirty miRNAs were associated with p16(INK4 )status while only a few miRNAs were associated with BRCA1, PIK3CA/PTEN and TP53 mutation status. Twelve miRNAs were associated with DNA copy number variation of the respective locus. CONCLUSION: Luminal-basal and epithelial-mesenchymal associated miRNAs determine the subdivision of miRNA transcriptome of breast cancer cell lines. Specific sets of miRNAs were associated with ERBB2 overexpression, p16(INK4a )or E-cadherin mutation or E-cadherin methylation status, which implies that these miRNAs may contribute to the driver role of these genetic aberrations. Additionally, miRNAs, which are located in a genomic region showing recurrent genetic aberrations, may themselves play a driver role in breast carcinogenesis or contribute to a driver gene in their vicinity. In short, our study provides detailed molecular miRNA portraits of breast cancer cell lines, which can be exploited for functional studies of clinically important miRNAs

SUSTAINABLE DENTISTRY. TO REDUCE OUR IMPACT ON THE ENVIRONMENT

Aim: The European Parliament has voted In march 2019 for a ban of single-use plastics to come into force by 2021. Dentistry objectives are to diminish its environmental footprint by adopting the 4R’s conceptreduce, reuse, recycle, rethink-and through the switch to eco-friendly home oral hygiene products. Aim of this study was to evaluate the impact of at-home oral hygiene products on environment. Methods: Literature searches of free text and MeSH terms were performed using MedLine (PubMed), Scopus, and the Cochrane Library (from 1950 to March 2020). All searches were conducted using a combination of subject headings and free-text terms; the final search strategy was determined through several pre-searches. Results: The search strategy identified 23 potential articles: 8 from PubMed, 10 from Scopus and 5 from Cochrane. Most of the available studies focused on the environmental impact of toothbrush and on green alternatives. Precise data on Italian market were not available, as only estimates of consumption were found by search. More detailed data were available about the US market, where 1 billion toothbrushes are thrown away every year and this amount is enough to run around the Earth 4 times. Fifty million pounds of toothbrushes end in landfills in the US every year. Toothbrushes are made from propylene plastic and nylon, which are sourced non-renewable fossil fuels. The handle is made of polypropylene plastic, and when discarded isn’t recycled and it doesn't biodegrade. The bristles are made from nylon, and manufacturing it creates nitrous oxide, a greenhouse gas 300 times more potent than carbon dioxide. These plastics may end up in the oceans. It's estimated that by 2050 there will be more plastic than fish in the oceans. The same concept may be used when talking about dental floss, that is 100% nylon made. Eco-friendly alternatives for toothbrushes are: i) wooden toothbrush with pig bristles, 100% biodegradable, not suitable for those with ethical concerns or vegan; ii) wooden toothbrush with nylon bristles, that have to be separated and thrown in the mixed waste; iii) silicone based toothbrushes; iv) plastic handle toothbrushes with changeable bristles. Alternatives for nylon dental floss are: i) silk wax floss, contained in glass and aluminum dispensers with floss- refills on sale; ii) silk and beeswax floss, in a cardboard or bio-plastic box, that are completely biodegradable. Scanty data are available on the efficacy and efficiency of these products on oral hygiene. Further clinical studies are needed to validate the eco-friendly alternatives of traditional toothbrushes and dental flosses. Conclusion: In conclusion, consciousness about the environmental impact of oral hygiene products should increase among stakeholders and decision makers. Further research should concentrate efforts on development and production of sustainable and eco-friendly alternatives with proved clinical efficacy

ORGANIC TOOTHPASTE FORMULATIONS: AN OVERVIEW

Aim: Aim of this study was to conduct a literature overview to: (i) identify and classify the ingredients of organic toothpastes; (ii) evaluate each ingredient adverse events associated with use. Methods: A list of available organic toothpastes currently marketed in Italy was compiled. Then Google Scholar database was searched to classify each ingredient. The known adverse events associated with use were listed. Results: Twenty organic toothpastes marketed in Italy were included in this study. A total of 70 single ingredients were coded: 62 (88.2%) and 8 (11.8%) ingredients were classified as active and inactive, respectively. Overall, 15 (21%) ingredients were associated with an adverse event. Almost half of the inactive ingredients presented an adverse known event associated with its long-term use. Enamel demineralization, skin and eye irritation were the main reported adverse events. Conclusion: Based on the findings of this overview, organic toothpastes formulations are characterized by favorable biocompatibility. Toothpastes ingredients with potentially known adverse events, like synthetic polymers like PEG and carbomers, detergent agents like sodium lauryl sulfate and Triclosan were not listed in the organic formulations. Organic formulations may be preferred for daily use, however further research to validate the clinical efficacy is required

FUNCTIONAL FOODS: GREEN TEA AND ORAL HEALTH

Aim: The definition of “functional foods” is: “healthful foods or food ingredients that have a potential health benefit beyond their nutrient content when consumed regularly in typical quantities as part of a varied diet”. Aim of this study was to evaluate the health-promoting effects of green tea on oral health. Methods: This review was conducted according to the PRISMA statement. In vivo studies on dentate humans were included without restriction on language and year of publication. Literature searches were performed using MedLine (PubMed), Scholar and Scopus. The following characteristics were collected :study year, type and setting; age, size and recruitment sample; case and control interventions; pre-treatment and cointervention; vehicle, daily dose and the total dose; consumption frequency and length; wash out period in RCTs with cross-over design; follow-up, drop-out and sample size at follow-up. Results: Ten studies were included in this review. All the included studies were published in the last ten years. The vehicle products for green tea were: mouth rinse, chewing gum, toothpaste, drinking tea, strips. The Jadad-scale for RCTs evaluated the included studies with high quality. The health-promoting effects of green tea are due to its polyphenol components (catechins). Moreover, the polyphenol concentration in green tea is higher than in black tea, with a greater antioxidant and anti-inflammatory effects, and antibacterial, antiviral, antimutagenic and antiaging properties.The preventive role of green tea in the development and progression of oral diseases has been shown in chronic periodontitis within effects on periodontopathogens and on host immune reactions. Conclusion: In conclusion, there is a growing number of clinical trials investigating the use of green tea as an adjunct to the prevention and treatment of oral diseases. Further studies are needed to validate its use in comparison with the standard of care