The Comet Assay as a Tool in Human Biomonitoring Studies of Environmental and Occupational Exposure to Chemicals-A Systematic Scoping Review

Biomonitoring of human populations exposed to chemical substances that can act as potential mutagens or carcinogens, may enable the detection of damage and early disease prevention. In recent years, the comet assay has become an important tool for assessing DNA damage, both in environmental and occupational exposure contexts. To evidence the role of the comet assay in human biomonitoring, we have analysed original research studies of environmental or occupational exposure that used the comet assay in their assessments, following the PRISMA-ScR method (preferred reporting items for systematic reviews and meta-analyses extension for scoping reviews). Groups of chemicals were designated according to a broad classification, and the results obtained from over 300 original studies (n = 123 on air pollutants, n = 14 on anaesthetics, n = 18 on antineoplastic drugs, n = 57 on heavy metals, n = 59 on pesticides, and n = 49 on solvents) showed overall higher values of DNA strand breaks in the exposed subjects in comparison with the unexposed. In summary, our systematic scoping review strengthens the relevance of the use of the comet assay in assessing DNA damage in human biomonitoring studies.

Retro-Inverso Collagen Modulator Peptide Derived from Serpin A1 with Enhanced Stability and Activity In Vitro

The rising demand for novel cosmeceutical ingredients has highlighted peptides as a significant category. Based on the collagen turnover modulation properties of SA1-III, a decapeptide derived from a serine protease inhibitor (serpin A1), this study focused on designing shorter, second-generation peptides endowed with improved properties. A tetrapeptide candidate was further modified employing the retro-inverso approach that uses d-amino acids aiming to enhance peptide stability against dermal enzymes. Surprisingly, the modified peptide AAT11RI displayed notably high activity in vitro, as compared to its precursors, and suggested a mode of action based on the inhibition of collagen degradation. It is worth noting that AAT11RI showcases stability against dermal enzymes contained in human skin homogenates due to its rationally designed structure that hampers recognition by most proteases. The rational approach we embraced in this study underscored the added value of substantiated claims in the design of new cosmeceutical ingredients, representing a rarity in the field.

Long-term cryopreservation of potassium bromate positive assay controls for measurement of oxidatively damaged DNA by the Fpg-modified comet assay: results from the hCOMET ring trial

The formamidopyrimidine DNA glycosylase (Fpg)-modified comet assay is widely used for the measurement of oxidatively generated damage to DNA. However, there has not been a recommended long-term positive control for this version of the comet assay. We have investigated potassium bromate as a positive control for the Fpg-modified comet assay because it generates many Fpg-sensitive sites with a little concurrent generation of DNA strand breaks. Eight laboratories used the same procedure for the treatment of monocytic THP-1 cells with potassium bromate (0, 0.5, 1.5, and 4.5 mM) and subsequent cryopreservation in a freezing medium consisting of 50% foetal bovine serum, 40% RPMI-1640 medium, and 10% dimethyl sulphoxide. The samples were analysed by the Fpg-modified comet assay three times over a 3-year period. All laboratories obtained a positive concentration-response relationship in cryopreserved samples (linear regression coefficients ranging from 0.79 to 0.99). However, there was a wide difference in the levels of Fpg-sensitive sites between the laboratory with the lowest (4.2% Tail DNA) and highest (74% Tail DNA) values in THP-1 cells after exposure to 4.5 mM KBrO3. In an attempt to assess sources of inter-laboratory variation in Fpg-sensitive sites, comet images from one experiment in each laboratory were forwarded to a central laboratory for visual scoring. There was high consistency between measurements of %Tail DNA values in each laboratory and the visual score of the same comets done in the central laboratory (r = 0.98, P < 0.001, linear regression). In conclusion, the results show that potassium bromate is a suitable positive comet assay control.

DNA strand break levels in cryopreserved mononuclear blood cell lines measured by the alkaline comet assay: results from the hCOMET ring trial

The comet assay is widely used in biomonitoring studies for the analysis of DNA damage in leukocytes and peripheral blood mononuclear cells. Rather than processing blood samples directly, it can be desirable to cryopreserve whole blood or isolated cells for later analysis by the comet assay. However, this creates concern about artificial accumulation of DNA damage during cryopreservation. In this study, 10 laboratories used standardized cryopreservation and thawing procedures of monocytic (THP-1) or lymphocytic (TK6) cells. Samples were cryopreserved in small aliquots in 50% foetal bovine serum, 40% cell culture medium, and 10% dimethyl sulphoxide. Subsequently, cryopreserved samples were analysed by the standard comet assay on three occasions over a 3-year period. Levels of DNA strand breaks in THP-1 cells were increased (four laboratories), unaltered (four laboratories), or decreased (two laboratories) by long-term storage. Pooled analysis indicates only a modest positive association between storage time and levels of DNA strand breaks in THP-1 cells (0.37% Tail DNA per year, 95% confidence interval: -0.05, 0.78). In contrast, DNA strand break levels were not increased by cryopreservation in TK6 cells. There was inter-laboratory variation in levels of DNA strand breaks in THP-1 cells (SD = 3.7% Tail DNA) and TK6 reference sample cells (SD = 9.4% Tail DNA), whereas the intra-laboratory residual variation was substantially smaller (i.e. SD = 0.4%-2.2% Tail DNA in laboratories with the smallest and largest variation). In conclusion, the study shows that accumulation of DNA strand breaks in cryopreserved mononuclear blood cell lines is not a matter of concern.

Inter-laboratory variation in measurement of DNA damage by the alkaline comet assay in the hCOMET ring trial

The comet assay is a simple and versatile method for measurement of DNA damage in eukaryotic cells. More specifically, the assay detects DNA migration from agarose gel-embedded nucleoids, which depends on assay conditions and the level of DNA damage. Certain steps in the comet assay procedure have substantial impact on the magnitude of DNA migration (e.g. electric potential and time of electrophoresis). Inter-laboratory variation in DNA migration levels occurs because there is no agreement on optimal assay conditions or suitable assay controls. The purpose of the hCOMET ring trial was to test potassium bromate (KBrO3) as a positive control for the formamidopyrimidine DNA glycosylase (Fpg)-modified comet assay. To this end, participating laboratories used semi-standardized protocols for cell culture (i.e. cell culture, KBrO3 exposure, and cryopreservation of cells) and comet assay procedures, whereas the data acquisition was not standardized (i.e. staining of comets and image analysis). Segregation of the total variation into partial standard deviation (SD) in % Tail DNA units indicates the importance of cell culture procedures (SD = 10.9), comet assay procedures (SD = 12.3), staining (SD = 7.9) and image analysis (SD = 0.5) on the overall inter-laboratory variation of DNA migration (SD = 18.2). Future studies should assess sources of variation in each of these steps. On the positive side, the hCOMET ring trial demonstrates that KBrO3 is a robust positive control for the Fpg-modified comet assay. In conclusion, the hCOMET ring trial has demonstrated a high reproducibility of detecting genotoxic effects by the comet assay, but inter-laboratory variation of DNA migration levels is a concern.

Visual comet scoring revisited: a guide to scoring comet assay slides and obtaining reliable results

Measurement of DNA migration in the comet assay can be done by image analysis or visual scoring. The latter accounts for 20%-25% of the published comet assay results. Here we assess the intra- and inter-investigator variability in visual scoring of comets. We include three training sets of comet images, which can be used as reference for researchers who wish to use visual scoring of comets. Investigators in 11 different laboratories scored the comet images using a five-class scoring system. There is inter-investigator variation in the three training sets of comets (i.e. coefficient of variation (CV) = 9.7%, 19.8%, and 15.2% in training sets I-III, respectively). However, there is also a positive correlation of inter-investigator scoring in the three training sets (r = 0.60). Overall, 36% of the variation is attributed to inter-investigator variation and 64% stems from intra-investigator variation in scoring between comets (i.e. the comets in training sets I-III look slightly different and this gives rise to heterogeneity in scoring). Intra-investigator variation in scoring was also assessed by repeated analysis of the training sets by the same investigator. There was larger variation when the training sets were scored over a period of six months (CV = 5.9%-9.6%) as compared to 1 week (CV = 1.3%-6.1%). A subsequent study revealed a high inter-investigator variation when premade slides, prepared in a central laboratory, were stained and scored by investigators in different laboratories (CV = 105% and 18%-20% in premade slides with comets from unexposed and hydrogen peroxide-exposed cells, respectively). The results indicate that further standardization of visual scoring is desirable. Nevertheless, the analysis demonstrates that visual scoring is a reliable way of analysing DNA migration in comets.

Exosomes: Potential Next-Generation Nanocarriers for the Therapy of Inflammatory Diseases

Inflammatory diseases are common pathological processes caused by various acute and chronic factors, and some of them are autoimmune diseases. Exosomes are fundamental extracellular vesicles secreted by almost all cells, which contain a series of constituents, i.e., cytoskeletal and cytosolic proteins (actin, tubulin, and histones), nucleic acids (mRNA, miRNA, and DNA), lipids (diacylglycerophosphates, cholesterol, sphingomyelin, and ceramide), and other bioactive components (cytokines, signal transduction proteins, enzymes, antigen presentation and membrane transport/fusion molecules, and adhesion molecules). This review will be a synopsis of the knowledge on the contribution of exosomes from different cell sources as possible therapeutic agents against inflammation, focusing on several inflammatory diseases, neurological diseases, rheumatoid arthritis and osteoarthritis, intestinal bowel disease, asthma, and liver and kidney injuries. Current knowledge indicates that the role of exosomes in the therapy of inflammation and in inflammatory diseases could be distinctive. The main limitations to their clinical translation are still production, isolation, and storage. Additionally, there is an urgent need to personalize the treatments in terms of the selection of exosomes; their dosages and routes of administration; and a deeper knowledge about their biodistribution, type and incidence of adverse events, and long-term effects of exosomes. In conclusion, exosomes can be a very promising next-generation therapeutic option, superior to synthetic nanocarriers and cell therapy, and can represent a new strategy of effective, safe, versatile, and selective delivery systems in the future.

From Industrial Food Waste to Bioactive Ingredients: A Review on the Sustainable Management and Transformation of Plant-Derived Food Waste

According to the United Nations, approximately one-third of the food produced for human consumption is wasted. The actual linear "Take-Make-Dispose" model is nowadays obsolete and uneconomical for societies and the environment, while circular thinking in production systems and its effective adoption offers new opportunities and benefits. Following the "Waste Framework Directive" (2008/98/CE), the European Green Deal, and the actual Circular Economy Action Plan, when prevention is not possible, recovering an unavoidable food waste as a by-product represents a most promising pathway. Using last year's by-products, which are rich in nutrients and bioactive compounds, such as dietary fiber, polyphenols, and peptides, offer a wake-up call to the nutraceutical and cosmetic industry to invest and develop value-added products generated from food waste ingredients.

Testicular and Haematological Cancer Induce Very High Levels of Sperm Oxidative Stress

Cancer impairs spermatogenesis, whereas results on sperm DNA integrity are controversial and no data are available about sperm oxidative stress. In cancer patients, we detected sperm DNA fragmentation (sDF) and both viable (ROS production in viable sperm fraction/viable spermatozoa) and total (ROS production in viable sperm fraction/total spermatozoa) oxidative stress. We found that cancer (22.50 (17.00-26.75)%, n = 85) increased sDF with respect to the control groups in both normozoospermic subfertile patients (NSP) (12.75 (8.63-14.88)%, n = 52, p < 0.001) and in healthy donors (HD) (8.50 (7.00-14.00)%, n = 19, p < 0.001). The induction of viable oxidative stress (n = 96) with cancer was even higher: 36.60 (24.05-58.65)% versus 11.10 (8.63-14.90)% in NSP (p < 0.001) and 9.60 (8.00-14.03)% in HD (p < 0.001). Similar, albeit lower, differences were found for total oxidative stress. SDF sharply correlated to viable oxidative stress when we considered all subjects (cancer patients and controls) (r = 0.591, p < 0.001, n = 134), but no correlation was found when only cancer patients were studied (r = 0.200; p > 0.05, n = 63). In conclusion, cancer significantly increases sDF and sperm oxidative stress levels. Additional mechanisms to oxidative attack might be responsible for increased sDF in cancer patients. Because sperm oxidative stress might affect the outcomes of sperm cryopreservation, of cancer treatments and of sperm epigenoma, the detection of oxidative stress could be of help in managing the reproductive issues of cancer patients.

Chemoenzymatic Synthesis of Glycopeptides to Explore the Role of Mucin 1 Glycosylation in Cell Adhesion

Posttranslational modifications affect protein biology in physiological and pathological conditions. Efficient methods for the preparation of peptides and proteins carrying defined, homogeneous modifications are fundamental tools for investigating these functions. In the case of Mucin 1 (MUC1) an altered glycosylation pattern is observed in carcinogenesis. To better understand the role of MUC1 glycosylation in interaction and adhesion of cancer cells, we prepared a panel of homogeneously O-glycosylated MUC1 peptides using a quantitative chemoenzymatic approach. Cell adhesion experiments with MCF-7 cancer cells on surfaces carrying up to 6 differently glycosylated MUC1 peptides demonstrated that different glycans significantly impact adhesion. This finding suggests a distinct role of MUC1 glycosylation patterns in cancer cell migration and/or invasion. To decipher the molecular mechanism for the observed adhesion we investigated conformation of the glycosylated MUC1 peptides by NMR. These experiments revealed only minor differences in peptide structure, therefore clearly relating the adhesion behaviour to the type and number of glycans linked to MUC1.

P-068 Oxidative stress and DNA fragmentation of spermatozoa in patients with cancer

Study question

Does cancer increase sperm DNA fragmentation (sDF) level by increasing oxidative stress in human spermatozoa?

Summary answer

Cancer increases both sDF and oxidative stress, but further studies are necessary to understand whether higher levels of ROS are responsible for sperm DNA damage.

What is known already

In recent years, it has been emerging that not only oncological therapies but also cancer itself can induce abnormal spermatogenesis. In addition, several Authors reported that occurrence of malignancy provokes also increases of sperm DNA damage, although such finding was not confirmed by others and the possible mechanisms responsible for such damage are presently unknown

Study design, size, duration

This was a prospective observational study conducted from 2018 to today, conducted in 102 patients affected by cancer and in 66 control subjects.

Participants/materials, setting, methods

We recruited 102 patients affected by cancer and 66 male partners of infertile couples as control subjects, in the Andrology Clinic of University of Florence. Control subjects were normozoospermic with absence of leukocytospermia, semen viscosity, smoking habit and recent antibiotic therapies. In the recruited men, we evaluated standard semen parameters, sperm DNA Fragmentation with SCD (Sperm Chromatin Dispersion) Test and oxidative stress as percentage of viable spermatozoa with MitoSOX™ Red labeling on total viable spermatozoa.

Main results and the role of chance

We found poorer standard semen parameters (sperm motility, concentration and number) in cancer patients (both testicular and hematological ones) with respect to control group, whereas no differences were observed between the two types of cancer. Testicular, but not hematological patients, were younger than control subjects. No difference was seen in the other tested characteristics (sperm morphology, abstinence, semen volume and pH, BMI). Regarding sDF, we found higher median values [IQR] in cancer patients (total: 22.25[17.00-25.95], n = 68; hematological: 23.00[20.13-26.38], n = 28; testicular: 21.13[16.13-25.73], n = 40) vs control subjects (12.50[8.25-14.75], n = 53); p &lt; 0.05, test U di Mann-Whitney. In addition, the amount of sperm oxidative stress was dramatically higher in patients with cancer (total:38.92[24.90-58.87], n = 79; hematological: 38.85[24.98-50.77], n = 34; testicular: 38.92[20.59-63.59], n = 45) vs control subjects (11.50[8.38-17.20], n = 62); p &lt; 0.05, test U di Mann-Whitney. We also studied the occurrence of a correlation between levels of sDF and oxidative stress. We found a sharp correlation when both cancer patients and control subjects were analysed (Spearman coefficient = 0.62, p &lt; 0.001, n = 103), but such correlation was completely lost when only cancer patients were considered (Spearman coefficient = 0.10, p &gt; 0.05, n = 50). This finding suggests that mechanisms different from ROS attack to DNA could explain the increase of sDF levels in cancer patients.

Limitations, reasons for caution

The study did not investigate, because of scarce availability of semen samples from cancer patients, other possible mechanisms (i.e apoptosis, defects in sperm chromatin maturation, failure in DNA system repair) which could cause the observed increase of sperm DNA damage in such patients.

Wider implications of the findings

Cancer patients show high levels of both sDF and oxidative stress. This finding rises concern, as cancer patients cryopreserve semen for using it with Assisted Reproductive Tecnhologies and both parameters represent a threat for natural and assisted reproduction. In addition, emerging evidence suggest that oxidative stress may alter sperm epigenome.

Trial registration number

not applicable

POS1307 HEMATOLOGICAL MANIFESTATIONS IN THE PRESENCE OF ANTIPHOSPHOLIPID ANTIBODIES IN A PEDIATRIC COHORT

Background

Antiphospholipid syndrome (APS) is an autoimmune disease characterized by thrombotic events (TEs) and/or pregnancy morbidity, in association with two consecutive positive determinations (at least 12 weeks apart) of antiphospholipid antibodies (aPLs). Several manifestations which are not considered clinical criteria of APS have been identified, including hematologic disorders. 1

Objectives

To identify the different variables associated with the development of hematological manifestations in the presence of aPLs in a pediatric cohort.

Methods

Multicentric historical cohort of children ≤ 18 years from three Spanish and one Italian tertiary referral hospitals with at least 2 positive determinations (≥12 weeks apart) of IgG/IgM anticardiolipin (aCL), IgG/IgM anti β2-glycoprotein I (aβ2GP) and/or LA. Demographic, clinical and analytical data were collected. A bivariate and multivariate analysis were carried out. Multicollinearity was also explored to build the model.

Results

131 children were included. Demographic, clinical, analytical data; and results of bivariant analysis are shown in Table 1.

Table 1.

Demographic characteristics; non-thrombotic clinical manifestations; immunologic laboratory findings; and bivariate analysis according to each specific entity and the occurrence of “hematological” manifestations. Categorical variables expressed as number (n) and percentage (%); Numerical variables with normal distribution expressed as mean and SD (standard deviation). * p<0.05.

VariablesTotaln= 131Hematological manifestationsn= 55Absence of hematological manifestationsn= 76P-valueSex, female, n (%)85 (64.9)39 (70.9)46 (60.5)0.219Age, years, mean (SD)10.9 (5.1)10.8 (5.03)10.9 (5.2)0.974Rage, n (%)0.126 Caucasian105 (81.4)43 (79.6)62 (82.7) Maghreb9 (7)2 (3.7)7 (9.3) Latinoamerican8 (6.2)6 (11.1)2 (2.7) Asian5 (3.9)3 (5.6)2 (2.7)Family history of AIDs, n (%)33 (25.2)17 (33.3)16 (21.1)0.122SLE diagnosis, n (%)34 (26)20 (36.4)14 (18.4)0.021*Thrombotic events, n (%)16 (12.2)7 (12.7)9 (11.8)0.879Hematological, n (%)55 (42)--- Thrombocytopenia30 (22.9) Leucopenia16 (8.4) Hemolytic anemia7 (5.3) Evans syndrome2 (1.2)Neurological, n (%)26 (20)10 (18.2)16 (21.3)0.657 Chorea8 (6.1) Epilepsy5 (3.8) Migraine4 (3)Cutaneous, n (%)23 (17.6)6 (10.9)17 (22.4)0.089 Raynaud17 (13) Livedo5 (3.1)Cardiac, n (%)22 (16.8)12 (21.8)10 (13.2)0.191Renal, n (%)2 (1.5)0 (0)2 (2.6)0.225aCL, n (%) IgG54 (41.2)24 (43.6)30 (39.5)0.633 IgM31 (23.7)20 (36.4)11 (14.5)0.004*aB2GP, n (%) IgG59 (45)29 (52.7)30 (39.5)0.132 IgM24 (18.3)16 (29.1)8 (10.5)0.007*LA, n (%)76 (58.5)37 (67.3)39 (52)0.081aPL profile, n (%) Simple76 (58)25 (45.5)51 (67.1)0.008* Double30 (22.9)13 (23.6)17 (22.4) Triple25 (19.1)17 (30.9)8 (10.5)ANA +, n (%)72 (59.5)33 (66)39 (54.9)0.222

The multivariate analysis identified as independent risk factors to develop a hematological manifestation, children with: SLE diagnosis [OR 1.2, 95 CI (0.5-5.8), p= 0.015], cutaneous manifestations [OR 1.01, 95 CI (0.6 -2.8), p= 0.091], LA + [OR 0.8, 95 CI (0.4 -3.6), p= 0.058], and IgG aβ2GP + [OR 0.9, 95 CI (0.4 - 3.9), p= 0.048]. Sex, age, familiar history of AIDs or IgM B2GP+ did not show a higher risk.

Conclusion

Non-criteria manifestations, specially hematologic disorders, are the most frequent events in the presence of aPLs in our cohort. Cutaneous manifestations, a positive personal history of SLE, LA positivity and IgG aβ2GP positivity were associated with a higher risk of developing hematological manifestations. Therefore, their inclusion as APS classification criteria should be considered.

References

[1]Abreu MM, Danowski A, Wahl DG, et al. The relevance of “non-criteria” clinical manifestations of antiphospholipid syndrome: 14th International Congress on Antiphospholipid Antibodies Technical Task Force Report on Antiphospholipid Syndrome Clinical Features. Autoimmun Rev. 2015

Disclosure of Interests

None declared

The comet assay for the evaluation of gut content genotoxicity: Use in human studies as an early biomarker of colon cancer risk

This short narrative review describes the use of the comet assay to evaluate the formation of genotoxic compounds in the gut lumen in human studies. The fecal water genotoxicity assay is based on ability of the gut content to induce genotoxicity in a cellular model, employing the aqueous component of the feces (fecal water) as this is supposed to contain most of the reactive species and to convey them to the intestinal epithelium. This non-invasive and low-cost assay has been demonstrated to be associated with colon cancer risk in animal models, and although the final validation against human tumors is lacking, it is widely used as a colo-rectal cancer risk biomarker in human nutritional intervention studies. The contribution given to the field of nutrition and cancer by the FW genotoxicity assay is highlighted, particularly in conjunction with other risk biomarkers, to shed light on the complex relationship among diet, microbiota, individual subject characteristics and the formation of genotoxic compounds in the gut.

Olive phenols preserve lamin B1 expression reducing cGAS/STING/NFκB-mediated SASP in ionizing radiation-induced senescence

Senescence occurs upon critical telomere shortening, or following DNA damage, oncogenic activation, hypoxia and oxidative stress, overall referred to stress-induced premature senescence (SIPS). In response to DNA damage, senescent cells release cytoplasmic chromatin fragments (CCFs), and express an altered secretome, the senescence-associated secretory phenotype (SASP), which contributes to generate a pro-inflammatory and pro-tumoral extracellular milieu. Polyphenols have gained significant attention owing to their anti-inflammatory and anti-tumour activities. Here, we studied the effect of oleuropein aglycone (OLE) and hydroxytyrosol (HT) on DNA damage, CCF appearance and SASP in a model of irradiation-induced senescence. Neonatal human dermal fibroblasts (NHDFs) were γ-irradiated and incubated with OLE, 5 µM and HT, 1 µM. Cell growth and senescence-associated (SA)-β-Gal-staining were used as senescence markers. DNA damage was evaluated by Comet assay, lamin B1 expression, release of CCFs, cyclic GMP-AMP Synthase (cGAS) activation. IL-6, IL-8, MCP-1 and RANTES were measured by ELISA assay. Our results showed that OLE and HT exerted a protective effect on 8 Gy irradiation-induced senescence, preserving lamin B1 expression and reducing cGAS/STING/NFκB-mediated SASP. The ability of OLE and HT to mitigate DNA damage, senescence status and the related SASP in normal cells can be exploited to improve the efficacy and safety of cancer radiotherapy.

Colon fibroblasts from Pirc rats (F344/NTac-Apcam1137 ) exhibit a proliferative and inflammatory phenotype that could support early stages of colon carcinogenesis

The role of fibroblast APC mutation in carcinogenesis is not clear. Apc^+/− colon fibroblasts have been previously characterized: however, little is known about their behavior at very early‐stage of colon carcinogenesis. We cultured colon mucosa fibroblasts (PCF, Apc^+/−) of Pirc rats (F344/NTac‐Apc^am1137) at an early stage of tumorigenesis, in absence of preneoplastic lesions, and of age‐matched wt (WCF): DNA damage levels, inflammatory phenotype and the expression of known markers of CAFs were analyzed. The latter were also assessed by microarray analysis on colon normal mucosa of Pirc and wt animals. PCF exhibited higher proliferative rates (P < .001) and delayed replicative senescence onset (P < .05) compared to WCF, along with a lower level of oxidative DNA damage (P < .05). Furthermore, a constitutively higher expression of COX‐2 and sensitivity to inflammatory stimuli was found in PCF compared to WCF (P < .05), accompanied by higher invasive capability (P < .05) and presence of cytoplasmic chromatin foci (cytoplasmic chromatin foci, P < .05). However, they neither expressed CAFs markers (α‐SMA, IL‐6) nor responded to CAFs activating stimuli (TGF‐β). Accordingly, CAFs markers and activating stimuli resulted down‐regulated in Pirc normal mucosa compared to wt, whereas DNA damage response and tolerance pathways were overexpressed. These data show for the first time that a proliferative and inflammatory phenotype characterizes Apc^+/− colon fibroblasts since very early stages of colon tumorigenesis, and indicate a role of Apc mutation in driving fibroblast phenotypic alterations that could support the establishment of a protumorigenic environment. Early pharmacological targeting of these dysfunctions might impact on tumor prevention in FAP patients.

What's new?

Heterozygous mutations in APC represent the earliest event in sporadic colorectal carcinogenesis onset and cause familial adenomatous polyposis syndrome. However, the role of APC‐mutated fibroblasts remains unclear. Here, Apc^+/‐ fibroblasts isolated from apparently‐normal colon tissue of Pirc rats showed proliferative, inflammatory features and resistance to oxidative DNA damage, although they did not show cancer‐associated fibroblast features. These data suggest that, at the very early stages of colon tumourigenesis, Apc‐mutated colon fibroblasts favour the establishment of a pro‐tumourigenic environment for pre‐neoplastic lesion development. Early pharmacological targeting of these dysfunctions might be valuable for tumour prevention in familial adenomatous polyposis patients.

Parvovirus B19 (B19V) induces cellular senescence in human dermal fibroblasts: putative role in SSc-associated fibrosis

OBJECTIVE

Emerging evidence demonstrates that excessive accumulation of senescent cells is associated with some chronic diseases and suggests a pathogenic role of cellular senescence in fibrotic processes, such as that occurring in aging or in systemic sclerosis (SSc). Recently, we demonstrated that parvovirus B19 (B19V) activates normal human dermal fibroblasts and induces expression of different profibrotic/proinflammatory genes. This observation prompted us to investigate whether it is also able to induce fibroblast senescence as a potential pathogenetic mechanism in B19V-induced fibrosis.

METHODS

Primary cultures of fibroblasts were infected with B19V and analyzed for the acquisition of senescence markers, such as morphological modifications, senescence-associated beta-galactosidase (SA-β-gal) activity, DNA damage response (DDR) and expression of senescence-associated secretory phenotype (SASP)-related factors.

RESULTS

We demonstrated that B19V-infected fibroblasts develop typical senescence features such as enlarged and flat-shaped morphology and SA-β-gal activity similar to that observed in SSc skin fibroblasts. They also developed a SASP-like phenotype characterized by mRNA expression and release of some proinflammatory cytokines, along with activation of transcription factor NFkB. Moreover, we observed B19V-induced DNA damage with the comet assay: a subpopulation of fibroblasts from B19V-infected cultures showed a significant higher level of DNA strand breaks and oxidative damage compared with mock-infected cells. Increased level and nuclear localization of ɣH2AX, a hallmark of DNA damage response, were also found.

CONCLUSIONS

B19V-induced senescence and production of SASP-like factors in normal dermal fibroblasts could represent a new pathogenic mechanism of non-productive B19V infection, which may have a role in the fibrotic process.

Phenolic Compounds and Triterpenes in Different Olive Tissues and Olive Oil By-Products, and Cytotoxicity on Human Colorectal Cancer Cells: The Case of Frantoio, Moraiolo and Leccino Cultivars (Olea europaea L.)

Phenolic and triterpenoid compounds of the olive tree are recognized as having a key role in health promotion, thanks to their multiple protective actions in humans. To expand the source of these bioactive compounds, the phenolic and triterpenoid profiles of leaf, branch, destoned fruit, destoned pomace, shell, seed, and extra virgin olive oil from the Frantoio, Leccino, and Moraiolo olive cultivars were simultaneously characterized by HPLC-DAD-MS. Overall, 43 molecules were quantitated and expressed on the obtained dry extracts. Oleuropein was mainly concentrated in branches (82.72 g/kg), fruits (55.79 g/kg), leaves (36.71 g/kg), and shells (1.26 g/kg), verbascoside (4.88 g/kg) in pomace, and nüzhenide 11-methyl oleoside (90.91 g/kg) in seeds. Among triterpenoids, which were absent in shells, the highest amount of oleanolic acid was found in olive leaves (11.88 g/kg). HCT-116 colorectal cells were chosen to assess the cytotoxicity of the dry extract, using the phytocomplex from Frantoio, which was the richest in phenols and triterpenoids. The IC₅₀ was also determined for 13 pure molecules (phenols and terpenoids) detected in the extracts. The greatest inhibition on the cell’s proliferation was induced by the branch dry extract (IC₅₀ 88.25 μg/mL) and by ursolic acid (IC₅₀ 24 μM). A dose-dependent relationship was observed for the tested extracts.

Characterization of substituted piperazines able to reverse MDR in Escherichia coli strains overexpressing resistance-nodulation-cell division (RND) efflux pumps

BACKGROUND

MDR in bacteria is threatening to public health. Overexpression of efflux pumps is an important cause of MDR. The co-administration of antimicrobial drugs and efflux pump inhibitors (EPIs) is a promising approach to address the problem of MDR.

OBJECTIVES

To identify new putative EPIs and to characterize their mechanisms of action.

METHODS

The effects of four selected piperazine derivatives on resistance-nodulation-cell division (RND) pumps was evaluated in Escherichia coli strains overexpressing or not expressing RND pumps by assays aimed at evaluating antibiotic potentiation, membrane functionality, ethidium bromide accumulation and AcrB expression. The cytotoxicity of selected piperazines towards primary cultures of human dermal fibroblasts was also investigated.

RESULTS

Four molecules enhanced levofloxacin activity against strains overexpressing RND efflux pumps (AcrAB-TolC and AcrEF-TolC), but not against RND pump-deficient strains. They had little effects on membrane potential. Molecule 4 decreased, whereas the other three increased, membrane permeability compared with untreated control cells. The four molecules showed differences in the specificity of interaction with RND efflux pumps, by inactivating the transport of one or more antibiotics, and in the levels of ethidium bromide accumulation and of acrB expression inhibition.

CONCLUSIONS

Piperazine derivatives are good candidates as inhibitors of RND efflux pumps. They decreased the activity of RND pumps by mixed mechanisms of action. Small structural differences among the molecules can be critical in defining their behaviour.

Novel methods to detect ROS in viable spermatozoa of native semen samples

A crucial issue in male infertility work-up is to have reliable methods to detect oxidative stress in native semen samples. Here, we explored flow cytometric detection of Reactive Oxygen Species (ROS) in viable spermatozoa using native semen samples. To this aim, we challenged three fluorescent probes: CM-H2DCFDA, CellROX Green and MitoSOX Red. After excluding all non-sperm cells, each probe was coupled to a suitable stain to eliminate also semen apoptotic bodies and non-viable spermatozoa: Merocyanine 540 (M540) for CM-H2DCFDA and CellROX Green, and LIVE/DEAD Fixable Green Dead Cell Stain (LD-G) for MitoSOX Red. We found that CM-H2DCFDA was confined in the sperm midpiece, whereas CellROX Green and MitoSOX Red were localized in the head of spermatozoa. Treatment with H₂O₂ highly increased MitoSOX Red fluorescence (36.20 ± 5.24 vs 18.02 ± 2.25, %, p < 0.01), but not, or only slightly, the labelling with CMH2DCFDA (2.57 ± 1.70 vs 2.77 ± 1.43, p > 0.05) and CellROX Green (5.34 ± 3.18 vs 3.76 ± 2.04, p < 0.05), respectively. Menadione treatment highly increased CellROX Green (10.13 ± 5.85 vs 3.82 ± 2.70, p < 0.01) and MitoSOX Red (69.20 ± 27.14 vs 21.18 ± 7.96, %, p < 0.05), but not CM-H2DCFDA fluorescence (8.30 ± 11.56 vs 7.30 ± 9.19, p > 0.05). Further, only MitoSOX Red was able to detect spontaneous ROS generation during in vitro sperm incubation. We also detected DNA fragmentation by Comet and SCD Assay after sorting MitoSOX Red positive and negative sperm viable fractions. Results indicated that MitoSOX labelling in viable spermatozoa was strictly associated to sperm DNA fragmentation. In conclusion, MitoSOX Red/LD-G appears to be a promising method to detect oxidative stress in human semen for male infertility work-up.

DNA damage in circulating leukocytes measured with the comet assay may predict the risk of death

The comet assay or single cell gel electrophoresis, is the most common method used to measure strand breaks and a variety of other DNA lesions in human populations. To estimate the risk of overall mortality, mortality by cause, and cancer incidence associated to DNA damage, a cohort of 2,403 healthy individuals (25,978 person-years) screened in 16 laboratories using the comet assay between 1996 and 2016 was followed-up. Kaplan–Meier analysis indicated a worse overall survival in the medium and high tertile of DNA damage (p < 0.001). The effect of DNA damage on survival was modelled according to Cox proportional hazard regression model. The adjusted hazard ratio (HR) was 1.42 (1.06–1.90) for overall mortality, and 1.94 (1.04–3.59) for diseases of the circulatory system in subjects with the highest tertile of DNA damage. The findings of this study provide epidemiological evidence encouraging the implementation of the comet assay in preventive strategies for non-communicable diseases.

Enhanced Vasculogenic Capacity Induced by 5-Fluorouracil Chemoresistance in a Gastric Cancer Cell Line

Chemotherapy is still widely used as a coadjutant in gastric cancer when surgery is not possible or in presence of metastasis. During tumor evolution, gatekeeper mutations provide a selective growth advantage to a subpopulation of cancer cells that become resistant to chemotherapy. When this phenomenon happens, patients experience tumor recurrence and treatment failure. Even if many chemoresistance mechanisms are known, such as expression of ATP-binding cassette (ABC) transporters, aldehyde dehydrogenase (ALDH1) activity and activation of peculiar intracellular signaling pathways, a common and universal marker for chemoresistant cancer cells has not been identified yet. In this study we subjected the gastric cancer cell line AGS to chronic exposure of 5-fluorouracil, cisplatin or paclitaxel, thus selecting cell subpopulations showing resistance to the different drugs. Such cells showed biological changes; among them, we observed that the acquired chemoresistance to 5-fluorouracil induced an endothelial-like phenotype and increased the capacity to form vessel-like structures. We identified the upregulation of thymidine phosphorylase (TYMP), which is one of the most commonly reported mutated genes leading to 5-fluorouracil resistance, as the cause of such enhanced vasculogenic ability.

Potassium bromate as positive assay control for the Fpg-modified comet assay

The comet assay is a popular assay in biomonitoring studies. DNA strand breaks (or unspecific DNA lesions) are measured using the standard comet assay. Oxidative stress-generated DNA lesions can be measured by employing DNA repair enzymes to recognise oxidatively damaged DNA. Unfortunately, there has been a tendency to fail to report results from assay controls (or maybe even not to employ assay controls). We believe this might have been due to uncertainty as to what really constitutes a positive control. It should go without saying that a biomonitoring study cannot have a positive control group as it is unethical to expose healthy humans to DNA damaging (and thus potentially carcinogenic) agents. However, it is possible to include assay controls in the analysis (here meant as a cryopreserved sample of cells i.e. included in each experiment as a reference sample). In the present report we tested potassium bromate (KBrO3) as a positive comet assay control for the formamidopyrimidine DNA glycosylase (Fpg)-modified comet assay. Ten laboratories used the same procedure for treatment of monocytic THP-1 cells with KBrO3 (0.5, 1.5 and 4.5 mM for 1 h at 37°C) and subsequent cryopreservation. Results from one laboratory were excluded in the statistical analysis because of technical issues in the Fpg-modified comet assay. All other laboratories found a concentration-response relationship in cryopreserved samples (regression coefficients from 0.80 to 0.98), although with different slopes ranging from 1.25 to 11.9 Fpg-sensitive sites (%DNA in tail) per 1 mM KBrO3. Our results demonstrate that KBrO3 is a suitable positive comet assay control.

Collection and storage of human white blood cells for analysis of DNA damage and repair activity using the comet assay in molecular epidemiology studies

DNA damage and repair activity are often assessed in blood samples from humans in different types of molecular epidemiology studies. However, it is not always feasible to analyse the samples on the day of collection without any type of storage. For instance, certain studies use repeated sampling of cells from the same subject or samples from different subjects collected at different time-points, and it is desirable to analyse all these samples in the same comet assay experiment. In addition, flawless comet assay analyses on frozen samples open up the possibility of using this technique on biobank material. In this article we discuss the use of cryopreserved peripheral blood mononuclear cells (PBMCs), buffy coat (BC) and whole blood (WB) for analysis of DNA damage and repair using the comet assay. The published literature and the authors' experiences indicate that various types of blood samples can be cryopreserved with only a minor effect on the basal level of DNA damage. There is evidence to suggest that WB and PBMCs can be cryopreserved for several years without much effect on the level of DNA damage. However, care should be taken when cryopreserving WB and BCs. It is possible to use either fresh or frozen samples of blood cells, but results from fresh and frozen cells should not be used in the same dataset. The article outlines detailed protocols for the cryopreservation of PBMCs, BCs and WB samples.

Synthesis of functionalised organochalcogenides and in vitro evaluation of their antioxidant activity

Differently substituted β-hydroxy- and β-amino dialkyl and alkyl-aryl tellurides and selenides have been prepared through ring-opening reactions of epoxides and aziridines with selenium- or tellurium-centered nucleophiles. The antioxidant properties and the cytotoxicity of such compounds have been investigated on normal human dermal fibroblasts. Most of the studied compounds exhibited a low cytotoxicity and a number of them proved to be non-toxic, not showing any effect on cell viability even at the highest concentration used (100 μM). The obtained results showed a significant antioxidant potential of the selected organotellurium compounds, particularly evident under conditions of exogenously induced oxidative stress. The antioxidant activity of selenium-containing analogues of active tellurides has also been evaluated on cells, highlighting that the replacement of Se with Te brought about a significant increase in the peroxidase activity.

The hCOMET project: International database comparison of results with the comet assay in human biomonitoring. Baseline frequency of DNA damage and effect of main confounders

The alkaline comet assay, or single cell gel electrophoresis, is one of the most popular methods for assessing DNA damage in human population. One of the open issues concerning this assay is the identification of those factors that can explain the large inter-individual and inter-laboratory variation. International collaborative initiatives such as the hCOMET project - a COST Action launched in 2016 - represent a valuable tool to meet this challenge. The aims of hCOMET were to establish reference values for the level of DNA damage in humans, to investigate the effect of host factors, lifestyle and exposure to genotoxic agents, and to compare different sources of assay variability. A database of 19,320 subjects was generated, pooling data from 105 studies run by 44 laboratories in 26 countries between 1999 and 2019. A mixed random effect log-linear model, in parallel with a classic meta-analysis, was applied to take into account the extensive heterogeneity of data, due to descriptor, specimen and protocol variability. As a result of this analysis interquartile intervals of DNA strand breaks (which includes alkali-labile sites) were reported for tail intensity, tail length, and tail moment (comet assay descriptors). A small variation by age was reported in some datasets, suggesting higher DNA damage in oldest age-classes, while no effect could be shown for sex or smoking habit, although the lack of data on heavy smokers has still to be considered. Finally, highly significant differences in DNA damage were found for most exposures investigated in specific studies. In conclusion, these data, which confirm that DNA damage measured by the comet assay is an excellent biomarker of exposure in several conditions, may contribute to improving the quality of study design and to the standardization of results of the comet assay in human populations.

Susceptibility of cosmeceutical peptides to proteases activity: Development of dermal stability test by LC-MS/MS analysis

Recently, several peptides are used as active ingredients in topical cosmetic formulations, few information are available on their dermal stability against proteases. In this study, it was developed a simple and reliable assay to evaluate the stability of cosmeceutical peptides in skin homogenates. The quantification of studied peptides was performed by liquid chromatography coupled with a triple quadrupole mass spectrometer operating in tandem mass spectrometry mode (LC-MS/MS) and the conditions were tuned through energy resolved MS/MS (ERMS) experiments. The sample preparation procedure was carried out on rat skin homogenates by employing pal-KTTKS (reference peptide and the parameters that may affect the assay results were evaluated, including substrate concentration, dilution of skin homogenate, protein concentration and batch-to-batch variation of the homogenate. The optimized conditions were applied to check the degradation profile of pal-KTTKS in human skin samples and the obtained results were compared. Finally, the degradation profiles of SA1-III and pamSA1-III, recently described as cosmeceutical peptides, in human skin homogenate were evaluated. The results showed that proposed peptides are stable toward proteases for up to 8 h of incubation. Thanks to this characteristic, these peptides can be considered very interesting candidates as active ingredients for creams intended for a daily application.

A clinical, histopathological and laboratory study of 19 consecutive Italian paediatric patients with chilblain-like lesions: lights and shadows on the relationship with COVID-19 infection

Background

Acral chilblain‐like lesions are being increasingly reported during COVID‐19 pandemic. However, only few patients proved positivity for SARS‐CoV‐2 infection. The relationship between this skin manifestation and COVID‐19 infection has not been clarified yet.

Objective

To thoroughly characterize a prospective group of patients with chilblain‐like lesions and to investigate the possible relationship with SARS‐CoV‐2 infection.

Methods

Following informed consent, patients underwent (i) clinical evaluation, (ii) RT‐PCR and serology testing for SARS‐CoV‐2, (iii) digital videocapillaroscopy of finger and toe nailfolds, (iv) blood testing to screen for autoimmune diseases and coagulation anomalies, and (v) skin biopsy for histopathology, direct immunofluorescence and, in selected cases, electron microscopy.

Results

Nineteen patients, all adolescents (mean age: 14 years), were recruited. 11/19 (58%) of them and/or their cohabitants reported flu‐like symptoms one to two months prior to skin manifestation onset. Lesions were localized to toes and also heels and soles. Videocapillaroscopy showed pericapillary oedema, dilated and abnormal capillaries, and microhaemorrhages both in finger and toe in the majority of patients. Major pathological findings included epidermal basal layer vacuolation, papillary dermis oedema and erythrocyte extravasation, perivascular and perieccrine dermal lymphocytic infiltrate, and mucin deposition in the dermis and hypodermis; dermal vessel thrombi were observed in two cases. Blood examinations were normal. Nasopharyngeal swab for SARS‐CoV‐2 and IgG serology for SARS‐CoV‐2 nucleocapsid protein were negative. Importantly, IgA serology for S1 domain of SARS‐CoV‐2 spike protein was positive in 6 patients and borderline in 3.

Conclusions

Chilblain‐like lesions during COVID‐19 pandemic have specific epidemiologic, clinical, capillaroscopic and histopathological characteristics, which distinguish them from idiopathic perniosis. Though we could not formally prove SARS‐CoV‐2 infection in our patients, history data and the detection of anti‐SARS‐COV‐2 IgA strongly suggest a relationship between skin lesions and COVID‐19. Further investigations on the mechanisms of SARS‐CoV‐2 infection in children and pathogenesis of chilblain‐like lesions are warranted.

Oxidative Stress and Inflammation as Targets for Novel Preventive and Therapeutic Approches in Non Communicable Diseases

As recently reported by the World Health Organization (WHO), Non-Communicable Diseases (NCDs) has been rising over the last century representing the main cause of death and disability for the general population regardless of age, region, or gender [...].

Chronic Resveratrol Treatment Reduces the Pro-angiogenic Effect of Human Fibroblast "Senescent-Associated Secretory Phenotype" on Endothelial Colony-Forming Cells: The Role of IL8

Senescent cells are characterized by an increased secretion of inflammatory and growth factors, known as the "senescence-associated secretory phenotype" (SASP), producing a pro-tumoral and pro-angiogenic microenvironment. This work proposes chronic resveratrol treatment (5 µM for 5 weeks, termed R5) of senescent MRC5 fibroblasts as a mean to mimic and target the angiogenic trait of stromal fibroblast SASP. Senescent fibroblast conditioned medium (CM sen) was effective in enhancing the angiogenic properties of endothelial colony-forming cells (ECFCs), that is, invasive activity and capillary morphogenesis capability in vitro, that were significantly reduced when conditioned media were collected after resveratrol pretreatment (CM senR5). The attenuation of ECFC angiogenic phenotype induced by CM senR5 was accompanied by reduced protein levels of epidermal growth factor and urokinase plasminogen activator receptors (EGFR, uPAR), and by a related decreased activation of receptor-tyrosine-kinase signaling pathways. IL8 levels were found reduced in CM senR5 compared to CM sen, with the associated reduction of IL8-CXCR2 binding in ECFCs. IL8-subtraction mitigated the pro-angiogenic features of CM sen and the associated intracellular signaling in ECFCs, indicating a prominent role of IL8 in the pro-angiogenic effects of CM sen. IL8 modulation is an important mechanism underlying the antiangiogenic activity of resveratrol on MRC5 SASP.

DNA damage in colon mucosa of Pirc rats, an Apc-driven model of colon tumorigenesis

APC mutation is the first event triggering colon carcinogenesis (CRC). The contribution of APC to colon mucosa DNA damage is not well characterized yet. Similarly, the role of genotoxin-producer gut microorganisms is unclear. DNA strand breaks and oxidative damage were measured in Pirc rats, mutated in Apc, with the COMET assay at age 1 (T₁) and 11 months (T₁₁), i.e. in absence and presence of colon adenomas. In Pirc colon mucosa a 2-fold increase in the mean level of DNA oxidative damage was found at T₁₁ compared to T₁. Moreover, the analysis of DNA damage distribution showed that the proportion of Pirc mucosa cells in the highest DNA damage class was increased compared to wt rats at T₁ and T₁₁ months (p < 0.05 and <0.001, respectively). The analysis of colon mucosa-associated microbiota composition showed that this result was not attributable to the presence of genotoxin-producer bacteria B. fragilis nor E. coli. However, Pirc colon mucosa was enriched in Clostridium cluster XI, harmful bacteria in the large intestine, while the wt colon mucosa was enriched in Clostridium cluster IV. This work provides an original way to investigate the interplay between Apc and gut microbiota in affecting DNA stability during CRC.

Fecal microbiome as determinant of the effect of diet on colorectal cancer risk: comparison of meat-based versus pesco-vegetarian diets (the MeaTIc study)

Background

Convincing evidence suggests that the risk of colorectal cancer (CRC) is increased by the typical Western diet characterized by high consumption of red and processed meat. In addition, some epidemiological studies suggest a reduction in the risk of CRC associated with fish consumption. The role of the gut microbiome in this diet-associated risk is not well understood.

Methods/design

This is a randomized parallel open clinical trial comprising a total of 150 clinically healthy subjects randomly assigned to three groups: a meat-based diet of which 4 portions per week are red meat (1 portion = 150 g), 3 portions per week are processed meat (1 portion = 50 g), and 1 portion per week is poultry (1 portion = 150 g), for a total amount of 900 g per week of meat and derivatives; a meat-based diet supplemented with alpha-tocopherol; and a pesco-vegetarian diet excluding fresh and processed meat and poultry, but which includes 3 portions per week of fish for a total amount of 450 g per week. Each intervention will last 3 months. The three diets will be isocaloric and of three different sizes according to specific energy requirements. Anthropometric measurements, body composition, and blood and fecal samples will be obtained from each participant at the beginning and end of each intervention phase. The measure of the primary outcome will be the change from baseline in DNA damage induced by fecal water using the comet assay in a cellular model. Secondary outcome measures will be changes in the profile of fecal microbiomes, global fecal and urinary peroxidation markers, and neoplastic biomarkers.

Discussion

Although epidemiological data support the promoting role of meat and the possible protective role of fish in colon carcinogenesis, no study has directly compared dietary profiles characterized by the presence of these two food groups and the role of the gut microbiome in these diet-associated CRC risks. This study will test the effect of these dietary profiles on validated CRC risk biomarkers.

Trial registration

ClinicalTrials.gov, NCT03416777. Registered on 3 May 2018.

miR-210-3p mediates metabolic adaptation and sustains DNA damage repair of resistant colon cancer cells to treatment with 5-fluorouracil

Chemoresistance is the primary cause of chemotherapy failure. Compelling evidence shows that micro RNAs (miRNAs) contribute to reprogram cancer cells toward a resistant phenotype. We investigate the role of miRNAs in the response to acute treatment with 5-FU in colon cancer-resistant cells. We performed a global gene expression profile for the entire miRNA genome and found a change in the expression of four miRNAs following acute treatment with 5-FU. Among them, we focused on miR-210-3p, previously described as a key regulator of DNA damage repair mechanisms and mitochondrial metabolism. We show that miR-210-3p downregulation enables resistant cells to counteract the toxic effect of the drug increasing the expression of RAD-52 protein, responsible for DNA damage repair. Moreover, miR-210-3p downregulation enhances oxidative phosphorylation (OXPHOS), increasing the expression levels of succinate dehydrogenase subunits D, decreasing intracellular succinate levels and inhibiting HIF-1α expression. Altogether, these adaptations lead to increased cells survival following drug exposure. These evidence suggest that miR-210-3p downregulation following 5-FU sustains DNA damage repair and metabolic adaptation to counteract drug treatment.

Opioid response in paediatric cancer patients and the Val158Met polymorphism of the human catechol-O-methyltransferase (COMT) gene: an Italian study on 87 cancer children and a systematic review

Background

Genetic polymorphisms in genes involved in pain modulation have been reported to be associated to opioid efficacy and safety in different clinical settings.

Methods

The association between COMT Val158Met polymorphism (rs4680) and the inter-individual differences in the response to opioid analgesic therapy was investigated in a cohort of 87 Italian paediatric patients receiving opioids for cancer pain (STOP Pain study). Furthermore, a systematic review of the association between opioid response in cancer patients and the COMT polymorphism was performed in accordance with the Cochrane Handbook and the Prisma Statement.

Results

In the 87 paediatric patients, pain intensity (total time needed to reach the lowest possible level) was significantly higher for G/G than A/G and A/A carriers (p-value = 0.042). In the 60 patients treated only with morphine, the mean of total dose to reach the same pain intensity was significantly higher for G/G than A/G and A/A carriers (p-value = 0.010). Systematic review identified five studies on adults, reporting that opioid dose (mg after 24 h of treatment from the first pain measurement) was higher for G/G compared to A/G and A/A carriers.

Conclusions

Present research suggests that the A allele in COMT polymorphism could be a marker of opioid sensitivity in paediatric cancer patients (STOP Pain), as well as in adults (Systematic Review), indicating that the polymorphism impact could be not age-dependent in the cancer pain context.

Trial registration

Registration number: CRD42017057831.

Electronic supplementary material

The online version of this article (10.1186/s12885-019-5310-4) contains supplementary material, which is available to authorized users.

Dietary Extra-Virgin Olive Oil Polyphenols Do Not Attenuate Colon Inflammation in Transgenic HLAB-27 Rats but Exert Hypocholesterolemic Effects through the Modulation of HMGCR and PPAR-α Gene Expression in the Liver

BACKGROUND

Human studies have demonstrated that olive oil phenolic compounds reduce inflammatory markers associated with chronic diseases.

OBJECTIVES

To explore the anti-inflammatory effects of extra-virgin olive oil polyphenols in an experimental model of inflammatory bowel disease (IBD).

METHODS

HLA-B27 transgenic rats were fed an AIN-76 diet containing 10% corn oil (CO) or extra-virgin olive oil with high (EVOO) or low phenolic content (ROO) for 3 months. Wild-type rats (WT) were fed the CO diet.

RESULTS

CO-fed HLA-B27 animals developed intestinal inflammation characterized by diarrhea, increased myeloperoxidase activity, and mucosal injury. None of these parameters were influenced by EVOO. Gene expression profiling indicated that proinflammatory pathways were upregulated in the colon mucosa of CO-fed HLA-B27 rats compared to WT, and this was further confirmed by RT-PCR for the iNOS, TNFα, and IL1β genes. EVOO significantly reduced TNFα gene expression in the colon mucosa and decreased total cholesterol blood levels compared to CO HLA-B27 rats (89.43 ± 3.66 vs. 111.5 ± 8.10 mg/dL, p < 0.05). This latter effect with EVOO was associated with reduced HMGCR and increased PPAR-α hepatic gene expression, compared to ROO.

CONCLUSION

These data indicate that olive oil polyphenols do not control colon inflammation in HLA-B27 transgenic rats but exert a positive effect on blood lipids by reducing total cholesterol levels. This preliminary result suggests the need to explore the efficacy of EVOO rich in polyphenols as a complementary strategy for managing hypercholesterolemia and to potentially limit statin-associated myotoxicity.

Folate, genomic stability and colon cancer: The use of single cell gel electrophoresis in assessing the impact of folate in vitro, in vivo and in human biomonitoring

Intake of folate (vitamin B₉) is strongly inversely linked with human cancer risk, particularly colon cancer. In general, people with the highest dietary intake of folate or with high blood folate levels are at a reduced risk (approx. 25%) of developing colon cancer. Folate acts in normal cellular metabolism to maintain genomic stability through the provision of nucleotides for DNA replication and DNA repair and by regulating DNA methylation and gene expression. Folate deficiency can accelerate carcinogenesis by inducing misincorporation of uracil into DNA, by increasing DNA strand breakage, by inhibiting DNA base excision repair capacity and by inducing DNA hypomethylation and consequently aberrant gene and protein expression. Conversely, increasing folate intake may improve genomic stability. This review describes key applications of single cell gel electrophoresis (the comet assay) in assessing genomic instability (misincorporated uracil, DNA single strand breakage and DNA repair capacity) in response to folate status (deficient or supplemented) in human cells in vitro, in rodent models and in human case-control and intervention studies. It highlights an adaptation of the SCGE comet assay for measuring genome-wide and gene-specific DNA methylation in human cells and colon tissue.

Serpin A1 and the modulation of type I collagen turnover: Effect of the C-terminal peptide 409-418 (SA1-III) in human dermal fibroblasts

The pharmacological modulation of collagen turnover is a strategy potentially useful in different skin conditions. The serine protease inhibitor Serpin A1 and portions of its C-terminal region have been investigated as collagen modulators. To clarify the mechanisms by which the C-terminal 409-418 peptide SA1-III increases extracellular type I collagen levels, to compare its activities range with that of the originator molecule Serpin A1, and to evaluate its efficacy in primary cultures from adult and aged human subjects. The different forms of type I collagen were analyzed by means of western blot in cell lysates and cell-conditioned media of primary human dermal fibroblasts obtained from subjects of different ages. Gelatin zymography was used to investigate the degrading enzymes. Cell viability and in vitro wound healing tests were used to evaluate cell proliferation. The SA1-III peptide increased extracellular collagen levels by reducing degradation, with no effect on cellular biosynthesis or cell proliferation mechanisms. A reduced level of MMP-2 and MMP-9 was also found in cell media upon peptide treatment. No peptide effect was detected on inflammatory mediators gene expression in resting and LPS-stimulated fibroblasts, or in the wound healing test. The SA1-III peptide is a good collagen modulator candidate, protecting collagen against degradation without detectable actions on biosynthesis, acting at reasonably low concentrations, and non-interfering with cell proliferation. It is effective in primary fibroblasts from young and aged subjects. These effects can prove useful in pathological and physiological skin conditions in which collagen degradation is excessive compared to the synthetic capacity.

Characterization of serious adverse drug reactions as cause of emergency department visit in children: a 5-years active pharmacovigilance study

Background

To describe frequency, preventability and seriousness of adverse drug reactions (ADRs) in children as cause of emergency department (ED) admission and to evaluate the association between specific factors and the reporting of ADRs.

Methods

A retrospective analysis based on reports of suspected ADRs collected between January 1st, 2012 and December 31st, 2016 in the ED of Meyer Children’s Hospital (Italy). Demographics, clinical status, suspected drugs, ADR description, and its degree of seriousness were collected. Logistic regression was used to estimate the reporting odds ratios (RORs) with 95% confidence intervals (CIs) of potential predictors of ADR seriousness.

Results

Within 5 years, we observed 834 ADRs (1100 drug-ADR pairs), of whom 239 were serious; of them, 224 led to hospitalization. Patients were mostly treated with one drug. Among patients treated with more than one drug, 78 ADRs presented a potential interaction. The most frequently reported ADRs involved gastrointestinal system. The most frequently reported medication class was antinfectives. Risk of serious ADR was significantly lower in children and infants compared to adolescents (ROR 0.41 [95% CI: 0.27–0.61] and 0.47 [0.32–0.71], respectively), and it was significantly increased in subjects exposed to more than one drug (ROR 1.87 [1.33–2.62] and 3.01 [2.07–4.37] for subjects exposed to 2 and 3 or more drugs, respectively). Gender, interactions and off-label drug use did not influence the risk of serious ADRs.

Conclusion

Active surveillance in pharmacovigilance might represent the best strategy to estimate and characterize the clinical burden of ADRs in children.

Electronic supplementary material

The online version of this article (10.1186/s40360-018-0207-4) contains supplementary material, which is available to authorized users.

Aging related changes in circulating reactive oxygen species (ROS) and protein carbonyls are indicative of liver oxidative injury

•

Circulating ROS and protein carbonyls increase as early as middle age.

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Oxidative DNA damage is increased in the liver of middle age rats.

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DNA damage repairing capacity is reduced in the liver of middle age rats.

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Circulating protein carbonyls are indicative of oxidative liver injury.

Oxidative stress, defined as an imbalance between the production of reactive oxygen species (ROS) and antioxidant defense mechanisms, plays a major role in inducing oxidative damage and cellular impairment, resulting in a general decline of the physiological functions. The aim of this work was to evaluate age-related changes in circulating ROS levels and plasma protein carbonyls, in very young (2 months aged), young (8 months aged) and in middle age (15 months aged) F344 rats. In addition, the DNA oxidative marker 8-hydroxy-2′-deoxyguanosine (8-OHdG) and the expression of the DNA repair enzymes APE1, OGG1 and UNG genes were also measured in the liver of these animals. We also determined whether systemic oxidative stress reflects oxidative injury at organ level. Our results demonstrate that the increase in circulating ROS and protein carbonyl content occurs as early as middle age. Moreover, increased 8-OHdG in the liver of 15-month-old rats was at least in part associated with a reduced DNA damage repairing capacity as suggested by the down-regulation of APE1 gene expression. In addition, we demonstrated for the first time, that plasma carbonyls and liver 8-OHdG are well correlated, suggesting that plasma protein carbonyls may be used as a surrogate marker of oxidative injury in target organs.

Pomegranate By-Products in Colorectal Cancer Chemoprevention: Effects in Apc-Mutated Pirc Rats and Mechanistic Studies In Vitro and Ex Vivo

SCOPE

To investigate the effect of pomegranate mesocarp, a polyphenol-rich by-product of juice production, in colorectal cancer (CRC) chemoprevention.

METHODS AND RESULTS

A mesocarp decoction (PMD) is administered for 6 weeks in the diet to Pirc rats, mutated in Apc, a key-gene in CRC. Mucin-depleted foci (MDFs), as CRC biomarkers, are reduced in PMD-fed rats compared to controls (MDF/colon: 34 ± 4 versus 47 ± 3, p = 0.02). There is an increase in apoptosis in MDFs from PMD-treated rats compared to controls (2.5 ± 0.2 versus 1.6 ± 0.2, p < 0.01). To elucidate the involved mechanisms, two colon-relevant metabolites of the polyphenolic and fiber PMD components, urolithin-A (u-A) and sodium butyrate (SB), are tested alone or in combination in vitro (colon cancer cells), and ex vivo in adenoma (AD) and normal mucosa (NM) from Pirc rats. u-A 25 μm plus SB 2.5 mm (USB) causes a significant reduction in COX-2 protein expression compared to untreated controls (about -70% in cancer cell cultures, AD, and NM), and a strong increase in C-CASP-3 expression in cells (about ten times), in AD and NM (+74 and +69%).

CONCLUSION

These data indicate a chemopreventive activity of PMD due, at least in part, to pro-apoptotic and anti-inflammatory action of its metabolites that could be exploited in high-risk patients.

Chronic Resveratrol Treatment Inhibits MRC5 Fibroblast SASP-Related Protumoral Effects on Melanoma Cells

Cellular senescence is related to organismal aging and is observed after DNA damaging cancer therapies, that induce tumor-suppressive modifications, but it is characterized by a strong increase in secreted factors, termed the "senescence-associated secretory phenotype" (SASP). Particularly, SASP from stroma senescent fibroblasts creates a cancer-favoring microenvironment, providing targets for anti-cancer interventions. In the present article, chronic treatment (5 weeks) with 5 µM resveratrol has been used to modulate senescence-related protumoral features of MRC5 fibroblasts, reducing SASP-related interleukins IL1α, IL1β, IL6, and IL8; transforming-growth-factor-β (TGFβ); matrix metallo-proteinases MMP3 and MMP2; urokinase plasminogen activator (uPA); receptor proteins uPAR, IL6R, insulin growth factor receptor-1 (IGF-1R), TGFβ-R2, and CXCR4. The cellular nuclear-factor-kB (NF-kB) protein level was also reduced, confirming its role in the induction of SASP. Resveratrol pretreated MRC5 fibroblasts were resistant to activation by TGFβ. Resveratrol treatment of senescent MRC5 induced the production of conditioned media (CM) which counteracted the protumoral effect of senescent CM on A375 and A375-M6 melanoma cell proliferation and invasiveness, and reduced the expression of epithelial-to-mesenchymal transition markers related to malignant features. This experimental approach proposes a treatment that targets the senescent stromal cell phenotype to induce an anti-tumor hosting microenvironment, which is suitable for both preventive and therapeutic purposes.

Nutrigenomics of extra-virgin olive oil: A review

Nutrigenomics data on the functional components of olive oil are still sparse, but rapidly increasing. Olive oil is the main source of fat and health-promoting component of the Mediterranean diet. Positive effects have been observed on genes involved in the pathobiology of most prevalent age- and lifestyle-related human conditions, such as cancer, cardiovascular disease and neurodegeneration. Other effects on health-promoting genes have been identified for bioactive components of olives and olive leafs. Omics technologies are offering unique opportunities to identify nutritional and health biomarkers associated with these gene responses, the use of which in personalized and even predictive protocols of investigation, is a main breakthrough in modern medicine and nutrition. Gene regulation properties of the functional components of olive oil, such as oleic acid, biophenols and vitamin E, point to a role for these molecules as natural homeostatic and even hormetic factors with applications as prevention agents in conditions of premature and pathologic aging. Therapeutic applications can be foreseen in conditions of chronic inflammation, and particularly in cancer, which will be discussed in detail in this review paper as major clinical target of nutritional interventions with olive oil and its functional components. © 2016 BioFactors, 43(1):17-41, 2017.

Serpin A1 C-Terminal Peptides as Collagen Turnover Modulators

The modulation of collagen turnover can be a relevant pharmacological target in the context of treating either pathological or pathophysiological conditions, such as collagen-related diseases and skin aging. Our recent work has focused on the search for short-chain peptides as lead compounds for further development of compounds that enhance the production of type I collagen. In this study we selected and synthesized overlapping peptides of the C-terminal portion of serpin A1 (residues 393-418), the impact of which on collagen production has been reported previously, in order to identify shorter and still active fragments and to provide insight on the mechanisms involved. The biological activity of each fragment was evaluated with cultured normal human dermal fibroblasts, and changes in the amounts of collagen were monitored in collected culture media by a sandwich ELISA technique developed in house. Interestingly, we identified a decapeptide, termed SA1-III (Ac-MGKVVNPTQK-NH2 ), as a promising candidate for our purposes; it is able to induce a significant increase in type I collagen levels in the culture medium of treated cells at micromolar concentrations.

Analysis of persistence of human papillomavirus infection in men evaluated by sampling multiple genital sites

OBJECTIVE

Although human papillomavirus (HPV) infection has been studied extensively in women, data on male infection are limited. The purpose of this study was to investigate persistence of HPV infection at multiple genital sites in men and to define potential associations with socio-behavioural characteristics.

PATIENTS AND METHODS

Penile, urethral and seminal specimens were tested by the INNO-LiPA HPV system (Innogenetics) and a PCR assay. Persistence was defined as the detection of same HPV type at ≥ 2 consecutive visits. The Kaplan-Meier method and the log-rank test were applied to estimate the likelihood of persistence.

RESULTS

A total of 50 men (median age: 33 years) were followed for a median of 14.7 months. Altogether, 49%, 36%, 26% and 11% of baseline HPV-positive men had 6-, 12-, 18- and 24-month persistent infection with any HPV type, respectively. The 6-, 12- and 18- month persistence was more common for oncogenic HPV infections; 24-month persistence was similar. The median duration of persistence was 21.7 months for any HPV. The median duration of persistence for any HPV type was significantly longer in the penile sample (22.5 months, 95% CI: 18.3-26.7) than the semen sample (15.3 months, 95% CI: 14.5-16.1).

CONCLUSIONS

Over a third of type-specific HPV infections in men remained persistent over a 24-month period. The median duration of HPV infection was longer in penile samples compared to seminal samples. As being increasing the attention of HPV vaccination as a potential preventive approach also for men, it is imperative to obtain additional insight on natural history of HPV infection in men, particularly as far as incidence and duration are concerned.

Double demonstration of oncogenic high risk human papilloma virus DNA and HPV-E7 protein in oral cancers

Oncogenic HPVs are necessarily involved in cervical cancer but their role in oral carcinogenesis is debated. To detect HPV in oral cancer, 38 cases of formalin fixed-paraffin embedded OSCC were studied by both DNA genotyping (MY09/11 L1 consensus primers in combination with GP5-GP6 primer pair followed by sequencing) and immunohistochemistry (monoclonal Abs against capsid protein and HPV-E7 protein, K1H8 DAKO and clone 8C9 INVITROGEN, respectively). HPV-16 tonsil cancer was used as positive control. The overall prevalence of HPV infection in OSCCs was 10.5%. Amplification of DNA samples showed single HPV DNA infection in 3 cases (HPV16; HPV53; HPV70) and double infection in one case of cheek cancer (HPV31/HPV44). The overall HR-HPV prevalence was 7.5%. E-7 antigen was immunohistochemically detected in all HPV-positive cases. HPV+ OSCC cases showed an overall better outcome than HPV negative oral cancers, as evaluated by Kaplan-Meier curves. HPVs exert their oncogenic role after DNA integration, gene expression of E5, E6 and E7 loci and p53/pRb host proteins suppression. This study showed that HPV-E7 protein inactivating pRb is expressed in oral cancer cells infected by oncogenic HPV other than classical HR-HPV-16/18. Interestingly HPV-70, considered a low risk virus with no definite collocation in oncogenic type category, gives rise to the expression of HPV-E7 protein and inactivate pRb in oral cancer. HPV-70, as proved in current literature, is able to inactivates also p53 protein, promoting cell immortalization. HPV-53, classified as a possible high risk virus, expresses E7 protein in OSCC, contributing to oral carcinogenesis. We have identified among OSCCs, a subgroup characterized by HPV infection (10.5%). Finally, we have proved the oncogenic potential of some HPV virus types, not well known in literature.