155 research outputs found

    Lipid-modified G4-decoy oligonucleotide anchored to nanoparticles:delivery and bioactivity in pancreatic cancer cells

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    KRAS is mutated in >90% of pancreatic ductal adenocarcinomas. As its inactivation leads to tumour regression, mutant KRAS is considered an attractive target for anticancer drugs. In this study we report a new delivery strategy for a G4-decoy oligonucleotide that sequesters MAZ, a transcription factor essential for KRAS transcription. It is based on the use of palmitoyl-oleyl-phosphatidylcholine (POPC) liposomes functionalized with lipid-modified G4-decoy oligonucleotides and a lipid-modified cell penetrating TAT peptide. The potency of the strategy in pancreatic cancer cells is demonstrated by cell cytometry, confocal microscopy, clonogenic and qRT-PCR assays

    Potent Apoptotic Response Induced by Chloroacetamidine Anthrathiophenediones in Bladder Cancer Cells.

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    We previously found that two neighboring G-quadruplexes behave as a molecular switch controlling the expression of HRAS (Cogoi, S.; Schekotikhin, A. E.; Xodo, L. E. Nucl. Acids Res. 2014, DOI: 10.1093/nar/gku574). In this study we have designed anthrathiophenediones with two hloroacetamidine-containing side chains (CATDs) as G-quadruplex binders and have examined their anticancer activity in T24 bladder cancer cells bearing mutant HRAS and in T24 xenografts. The designed CATDs (3a 12e), bearing alkyl side chains of different length, penetrate T24 cancer cells more than their analogues with guanidine-containing side chains. The lead compounds 3a and 3c inhibit HRAS expression, metabolic activity, and colony formation in T24 cancer cells. They also activate a strong apoptotic response, as indicated by PARP-1, caspases 3/7, and annexin V/propidium iodide assays. Apoptosis occurs under conditions where cyclin D1 is down-regulated and the cell cycle arrested in G2 phase. Finally, compound 3a inhibits the growth of T24 xenografts and increases the median survival time of nude mice

    Anticancer activity of cationic porphyrins in melanoma tumour-bearing mice and mechanistic in vitro studies

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    Background Porphyrin TMPyP4 (P4) and its C14H28-alkyl derivative (C14) are G-quadruplex binders and singlet oxygen (1O2) generators. In contrast, TMPyP2 (P2) produces 1O2 but it is not a G-quadruplex binder. As their photosensitizing activity is currently undefined, we report in this study their efficacy against a melanoma skin tumour and describe an in vitro mechanistic study which gives insights into their anticancer activity. Methods Uptake and antiproliferative activity of photoactivated P2, P4 and C14 have been investigated in murine melanoma B78-H1 cells by FACS, clonogenic and migration assays. Apoptosis was investigated by PARP-1 cleavage and annexin-propidium iodide assays. Biodistribution and in vivo anticancer activity were tested in melanoma tumour-bearing mice. Porphyrin binding and photocleavage of G-rich mRNA regions were investigated by electrophoresis and RT-PCR. Porphyrin effect on ERK pathway was explored by Western blots. Results Thanks to its higher lipophylicity C14 was taken up by murine melanoma B78-H1 cells up to 30-fold more efficiently than P4. When photoactivated (7.2 J/cm2) in B78-H1 melanoma cells, P4 and C14, but not control P2, caused a strong inhibition of metabolic activity, clonogenic growth and cell migration. Biodistribution studies on melanoma tumour-bearing mice showed that P4 and C14 localize in the tumour. Upon irradiation (660 nm, 193 J/cm2), P4 and C14 retarded tumour growth and increased the median survival time of the treated mice by ~50% (P <0.01 by ANOVA), whereas porphyrin P2 did not. The light-dependent mechanism mediated by P4 and C14 is likely due to the binding to and photocleavage of G-rich quadruplex-forming sequences within the 5\u2032-untranslated regions of the mitogenic ras genes. This causes a decrease of RAS protein and inhibition of downstream ERK pathway, which stimulates proliferation. Annexin V/propidium iodide and PARP-1 cleavage assays showed that the porphyrins arrested tumour growth by apoptosis and necrosis. C14 also showed an intrinsic light-independent anticancer activity, as recently reported for G4-RNA binders. Conclusions Porphyrins P4 and C14 impair the clonogenic growth and migration of B78-H1 melanoma cells and inhibit melanoma tumour growth in vivo. Evidence is provided that C14 acts through light-dependent (mRNA photocleavage) and light-independent (translation inhibition) mechanisms. Keywords: Melanoma B78-H1 cells; Cationic porphyrins; Biodistribution; C57/BL6 mice; Ras genes; G4-RNA; ERK pathwa

    The regulatory G4 motif of the Kirsten ras (KRAS) gene is sensitive to guanine oxidation: Implications on transcription

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    KRAS is one of the most mutated genes in human cancer. It is controlled by a G4 motif located upstream of the transcription start site. In this paper, we demonstrate that 8-oxoguanine (8-oxoG), being more abundant in G4 than in non-G4 regions, is a new player in the regulation of this oncogene. We designed oligonucleotides mimicking the KRAS G4-motif and found that 8-oxoG impacts folding and stability of the G-quadruplex. Dimethylsulphate-footprinting showed that the G-run carrying 8-oxoG is excluded from the G-tetrads and replaced by a redundant G-run in the KRAS G4-motif. Chromatin immunoprecipitation revealed that the base-excision repair protein OGG1 is recruited to the KRAS promoter when the level of 8-oxoG in the G4 region is raised by H2O2. Polyacrylamide gel electrophoresis evidenced that OGG1 removes 8-oxoG from the G4-motif in duplex, but when folded it binds to the G-quadruplex in a non-productive way. We also found that 8-oxoG enhances the recruitment to the KRAS promoter of MAZ and hnRNP A1, two nuclear factors essential for transcription. All this suggests that 8-oxoG in the promoter G4 region could have an epigenetic potential for the control of gene expression

    Rare spontaneous monochorionic dizygotic twins: a case report and a systematic review

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    Background: Monochorionic dizygotic twins are a rare condition, mostly related to assisted reproductive technology. This type of twinning is burdened by the same risk of pregnancy complications found in monochorionic monozygotic pregnancies. Case presentation: We report a case of spontaneous monochorionic dizygotic twins sharing situs inversus abdominalis and isolated levocardia, with only one twin affected by biliary atresia with splenic malformation syndrome. We also conducted a literature review of the 14 available documented monochorionic dizygotic twin gestations spontaneously conceived. Conclusions: It is still unclear how this unusual type of twinning can occur in spontaneous conception. The evidence so far suggest the importance to timely diagnose the chorionicity, in order to adequately manage the typical complications associated with monochorionicity

    Birth control knowledge among freshmen of four Italian universities

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    Since sexual health education (SHE) is not mandatory in Italian schools, we conducted a survey on freshmen of four Italian university campuses in 2012 to investigate the respective level of sexual health knowledge (SHK) in relation to birth control, with the aim to inform public health policy makers. A convenience strategy was employed to sample 4,552 freshmen registered with various undergraduate courses at four Italian universities: Padua university (Veneto Region); university of Milan (Lombardy Region); university of Bergamo (Lombardy Region); university of Palermo (Sicily Region). We investigated the level of SHK on birth control using 6 proxy indicators: (1) the average length of a woman\u2019s period [outcome with 3 levels: wrong (base) vs. acceptable vs. correct]; (2) the most fertile interval within a woman\u2019s period (binary outcome: correct vs. wrong answer); (3) the event between the end of a period and the beginning of the next cycle (binary outcome: correct vs. wrong answer); (4) the average survival of spermatozoa in the womb (binary outcome: correct vs. wrong answer); (5) the concept of contraception (binary outcome: correct vs. wrong answer); (6) the efcacy of various contraceptives to prevent unintended pregnancies (linear score: 0\u201317). We ftted 6 separate models of multiple regression: multinomial for outcome 1; logistic for outcomes 2, 3, 4, 6; linear for outcome 6. Statistical estimates were adjusted for a number of socio-demographic factors. Results were expressed as odds ratios (OR) for the 4 multiple logistic regression models, linear coefcients (RC) for the linear regression model and relative risk ratio (RRR) for the multinomial logistic regression model. The level of signifcance of each risk estimate was set at 0.05. The level of SHK of freshmen sampled was rather low, as 60% interviewees did not know the average length of a woman\u2019s period, the average survival of spermatozoa in the womb and the concept of contraception, whilst the most fertile interval within a woman\u2019s period was known only to 55% of interviewees. The mean score of SHK on the efcacy of various contraceptive methods was only 5 (scale 0\u201317). Some categories of students were consistently and signifcantly less knowledgeable on birth control at multivariable analysis: males; students from the university of Palermo; those with vocational secondary school education and those not in a romantic relationship at the time the survey was conducted. The results of this survey clearly call for the introduction of SHE programs in Italian schools, as already done in several European countries. School SHE should start as early as possible, ideally even before secondary school. SHE should be holistic and delivered with a multiple agency coordinated approach involving the Ministry of Health, the Ministry of Education, University and Scientifc Research (MIUR), families, schools, public health departments, primary health care providers, pharmacists, media, other

    Oxidative Stress Is Increased in Combined Oral Contraceptives Users and Is Positively Associated with High-Sensitivity C-Reactive Protein

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    Information concerning the mechanisms underlying oxidative stress and low-grade inflammation in young healthy women predisposing eventually to future diseases is scarce. We investigated the relationship of oxidative stress and high-sensitivity C-reactive protein (hsCRP) in fertile-age women by oral combined contraceptive (OC) use. Caucasian Italian healthy non-obese women (n = 290; 100 OC-users; 190 non-OC-users; mean age 23.2 \ub1 4.7 years) were analyzed. Blood hydroperoxides, as oxidative stress biomarkers, were assessed by Free Oxygen Radical Test (FORT). Serum hsCRP was determined by an ultra-sensitive method (hsCRP). Markedly elevated oxidative stress ( 65400 FORT Units) was found in 77.0% of OC-users and 1.6% of non-OC-users, odds ratio (OR) = 209, 95% CI = 60.9-715.4, p < 0.001. Elevated hsCRP levels 65 2.0 mg/L, considered risky for cardiovascular diseases (CVDs), were found in 41.0% of OC-users and 9.5% of non-OC-users, OR = 6.6, 95%CI 3.5-12.4, p < 0.001. Hydroperoxides were strongly positively correlated to hsCRP in all women (rs = 0.622, p < 0.001), in OC-users (rs = 0.442, p < 0.001), and in non-OC-users (rs = 0.426, p < 0.001). Women with hydroperoxides 65 400 FORT Units were eight times as likely to have hsCRP 65 2 mg/L. In non-OC-users only, hydroperoxides values were positively correlated with weight and body mass index, but negatively correlated with red meat, fish and chocolate consumption. Our research is the first finding a strong positive correlation of serum hydroperoxides with hsCRP, a marker of low-grade chronic inflammation, in young healthy women. Further research is needed to elucidate the potential role of these two biomarkers in OC-use associated side-effects, like thromboembolism and other CVDs

    A Survey on Knowledge, Prevention, and Occurrence of Sexually Transmitted Infections among Freshmen from Four Italian Universities

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    Background. The peak of sexually transmitted infections (STI) among adolescents/young adults suggests a low level of prevention. In order to assess whether the level of sexual health education (SHE), received by several channels, was effective at improving sexual behaviors, we conducted a survey among freshmen from four Italian universities. Methods. This observational cross-sectional study was carried out with an anonymous self-reported paper questionnaire, administered during teaching lectures to university freshmen of the northern (Padua, Bergamo, and Milan campuses) and southern (Palermo campus) parts of the country. Knowledge of STI (a linear numerical score), knowledge of STI prevention (dichotomous variable: yes vs. no) and previous STI occurrence (polytomous variable: "no"; "don't know"; "yes") were the outcomes in the statistical analysis. Results. The final number of freshmen surveyed was 4552 (97.9% response rate). The mean age of respondents was 21.4 ± 2.2 years and most of them (70.3%) were females. A total of 60% of students were in a stable romantic relationship. Only 28% respondents knew the most effective methods to prevent STI (i.e., condom and sexual abstinence), with a slightly higher prevalence of correct answers among females (31.3%) than males (25.8%). Students with history of STIs were 5.1%; they reported referring mostly to their general practitioner (GP) (38.1%) rather than discussing the problem with their partner (13.1%). At multivariable analysis, a significantly higher level of STI knowledge was observed in older students (25+ years of age), biomedical students, and those from a non-nuclear family; lower levels were found among students of the University of Palermo, and those who completed a vocational secondary school education. Those who had less knowledge about the most effective tools to prevent STIs included males, students from the University of Palermo, students registered with educational sciences, economics/political sciences, those of foreign nationality, and those whose fathers had lower educational levels. The risk of contracting a STI was significantly lower only in students not in a stable relationship (relative risk ratio, RRR = 0.67; 95% confidence interval, 95%CI = 0.48; 0.94), whereas such risk was significantly higher in students with higher STI knowledge (RRR = 1.15; 95%CI = 1.08; 1.22). Discussion and Conclusions. University freshmen investigated in this study had poor knowledge of STIs and their prevention. Unexpectedly, those with higher levels of knowledge had an increased risk of STIs. There have been no educational interventions-with good quality and long-term follow-ups-that increased the confidence that such SHE programs could have population level effects. A new high-quality study is therefore recommended to assess the effectiveness of an intervention generating behavioral changes; increasing only STI knowledge may not be sufficient

    Peri-Operative Management of Patients Undergoing Fenestrated-Branched Endovascular Repair for Juxtarenal, Pararenal and Thoracoabdominal Aortic Aneurysms: Preventing, Recognizing and Treating Complications to Improve Clinical Outcomes

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    The advent and refinement of complex endovascular techniques in the last two decades has revolutionized the field of vascular surgery. This has allowed an effective minimally invasive treatment of extensive disease involving the pararenal and the thoracoabdominal aorta. Fenestrated-branched EVAR (F/BEVAR) now represents a feasible technical solution to address these complex diseases, moving the proximal sealing zone above the renal-visceral vessels take-off and preserving their patency. The aim of this paper was to provide a narrative review on the peri-operative management of patients undergoing F/BEVAR procedures for juxtarenal abdominal aortic aneurysm (JAAA), pararenal abdominal aortic aneurysm (PRAA) or thoracoabdominal aortic aneurism (TAAA). It will focus on how to prevent, diagnose, and manage the complications ensuing from these complex interventions, in order to improve clinical outcomes. Indeed, F/BEVAR remains a technically, physiologically, and mentally demanding procedure. Intraoperative adverse events often require prolonged or additional procedures and complications may significantly impact a patient’s quality of life, health status, and overall cost of care. The presence of standardized preoperative, perioperative, and postoperative pathways of care, together with surgeons and teams with significant experience in aortic surgery, should be considered as crucial points to improve clinical outcomes. Aggressive prevention, prompt diagnosis and timely rescue of any major adverse events following the procedure remain paramount clinical needs

    G-quadruplex formation within the promoter of the KRAS proto-oncogene and its effect on transcription

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    In human and mouse, the promoter of the KRAS gene contains a nuclease hypersensitive polypurine–polypyrimidine element (NHPPE) that is essential for transcription. An interesting feature of the polypurine G-rich strand of NHPPE is its ability to assume an unusual DNA structure that, according to circular dichroism (CD) and DMS footprinting experiments, is attributed to an intramolecular parallel G-quadruplex, consisting of three G-tetrads and three loops. The human and mouse KRAS NHPPE G-rich strands display melting temperature of 64 and 73°C, respectively, as well as a K(+)-dependent capacity to arrest DNA polymerase. Photocleavage and CD experiments showed that the cationic porphyrin TMPyP4 stacks to the external G-tetrads of the KRAS quadruplexes, increasing the T(m) by ∼20°C. These findings raise the intriguing question that the G-quadruplex formed within the NHPPE of KRAS may be involved in the regulation of transcription. Indeed, transfection experiments showed that the activity of the mouse KRAS promoter is reduced to 20% of control, in the presence of the quadruplex-stabilizing TMPyP4. In addition, we found that G-rich oligonucleotides mimicking the KRAS quadruplex, but not the corresponding 4-base mutant sequences or oligonucleotides forming quadruplexes with different structures, competed with the NHPPE duplex for binding to nuclear proteins. When vector pKRS-413, containing CAT driven by the mouse KRAS promoter, and KRAS quadruplex oligonucleotides were co-transfected in 293 cells, the expression of CAT was found to be downregulated to 40% of the control. On the basis of these data, we propose that the NHPPE of KRAS exists in equilibrium between a double-stranded form favouring transcription and a folded quadruplex form, which instead inhibits transcription. Such a mechanism, which is probably adopted by other growth-related genes, provides useful hints for the rational design of anticancer drugs against the KRAS oncogene
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