Endogenous and artificial miRNAs explore a rich variety of conformations: a potential relationship between secondary structure and biological functionality

Mature microRNAs are short non-coding RNA sequences which upon incorporation into the RISC ribonucleoprotein complex, play a crucial role in regulation of gene expression. However, miRNAs can exist within the cell also as free molecules fulfilling their biological activity. Therefore, it is emerging that in addition to sequence even the structure adopted by mature miRNAs might play an important role to reach the target. Indeed, we analysed by several spectroscopic techniques the secondary structures of two artificial miRNAs selected by computational tool (miR-Synth) as best candidates to silence c-MET and EGFR genes and of two endogenous miRNAs (miR-15a and miR-15b) having the same seed region, but different biological activity. Our results demonstrate that both endogenous and artificial miRNAs can arrange in several 3D-structures which affect their activity and selectivity toward the targets.

Development of methods for the preparation of radiopure 82Se sources for the SuperNEMO neutrinoless double-beta decay experiment

A radiochemical method for producing 82Se sources with an ultra-low level of contamination of natural radionuclides (40K, decay products of 232Th and 238U) has been developed based on cation-exchange chromatographic purification with reverse removal of impurities. It includes chromatographic separation (purification), reduction, conditioning (which includes decantation, centrifugation, washing, grinding, and drying), and 82Se foil production. The conditioning stage, during which highly dispersed elemental selenium is obtained by the reduction of purified selenious acid (H2SeO3) with sulfur dioxide (SO2) represents the crucial step in the preparation of radiopure 82Se samples. The natural selenium (600 g) was first produced in this procedure in order to refine the method. The technique developed was then used to produce 2.5 kg of radiopure enriched selenium (82Se). The produced 82Se samples were wrapped in polyethylene (12 μm thick) and radionuclides present in the sample were analyzed with the BiPo-3 detector. The radiopurity of the plastic materials (chromatographic column material and polypropylene chemical vessels), which were used at all stages, was determined by instrumental neutron activation analysis. The radiopurity of the 82Se foils was checked by measurements with the BiPo-3 spectrometer, which confirmed the high purity of the final product. The measured contamination level for 208Tl was 8–54 μBq/kg, and for 214Bi the detection limit of 600 μBq/kg has been reached.

Circulating free tumor-derived DNA to detect EGFR mutations in patients with advanced NSCLC: French subset analysis of the ASSESS study

Background

The non-interventional ASSESS study (NCT01785888) evaluated the utility of circulating free tumor-derived DNA (ctDNA) from plasma for epidermal growth factor receptor (EGFR) mutation testing in patients with advanced non-small-cell lung cancer (NSCLC), in a real-world setting across 56 centers in Europe and Japan. The high mutation status concordance between 1162 matched tissue/cytology and plasma samples (89%, sensitivity =46%, specificity =97%) suggested that ctDNA is a feasible sample for EGFR mutation analysis. We report data for the French subset of patients (pre-planned analysis).

Methods

Eligible patients (stage IIIA/B/IV locally advanced/metastatic treatment-naive advanced NSCLC) provided diagnostic tissue/cytology and plasma samples. DNA extracted from tissue/cytology samples was subjected to EGFR mutation testing as per local practice; a designated laboratory performed ctDNA extraction/mutation testing of plasma samples. The primary outcome was EGFR mutation status concordance between matched tumor and plasma samples.

Results

Of the 1,311 patients enrolled in the ASSESS trial, 145 were recruited from 9 centers in France. Tumor samples from 130 patients were collected and 126 were evaluable for EGFR mutation analysis. Activating EGFR mutations were identified in 13 of the 126 patient tumor samples (EGFR mutation frequency 10.3%). For plasma testing, 10 of the 145 samples tested were positive for EGFR mutations (EGFR mutation frequency 6.9%). EGFR mutation rate was significantly higher in never- versus ever-smokers (stepwise logistic regression: tumor, P<0.0001; plasma, P=0.0008). Mutation status concordance between 126 matched patient samples was 96.0% [121/126; 95% confidence intervals (CI), 91.0-98.7]. Of the 113 EGFR mutation-negative patient tissue samples, one tested plasma-positive; reanalysis of plasma via two different techniques confirmed the presence of a L858R mutation, indicating a tissue false-negative result. Based on these data, sensitivity of plasma testing was 64.3% (9/14; 95% CI, 35.1-87.2%) and its specificity was 100.0% (112/112; 95% CI, 96.8-100.0%).

Conclusions

Data confirm ctDNA as an alternative sample for EGFR mutation analysis in patients with advanced NSCLC.

Anti-HIV activity of new higher order G-quadruplex aptamers obtained from tetra-end-linked oligonucleotides

By combining the ability of short G-rich oligodeoxyribonucleotides (ODNs) containing the sequence 5'CGGA3' to form higher order G-quadruplex (G4) complexes with the tetra-end-linked (TEL) concept to produce aptamers targeting the HIV envelope glycoprotein 120 (gp120), three new TEL-ODNs (1-3) having the sequence 5'CGGAGG3' were synthesized with the aim of studying the effect of G4 dimerization on their anti-HIV activity. Furthermore, in order to investigate the effect of the groups at the 5' position, the 5' ends of 1-3 were left uncapped (1) or capped with either the lipophilic dimethoxytrityl (DMT) (2) or the hydrophilic glucosyl-4-phosphate (3) moieties. The here reported results demonstrate that only the DMT-substituted TEL-ODN 2 is effective in protecting human MT-4 cell cultures from HIV infection (76% max protection), notwithstanding all the three new aptamers proved to be capable of forming stable higher order dimeric G4s when annealed in K+-containing buffer, thus suggesting that the recognition of a hydrophobic pocket on the target glycoprotein by the aptamers represents a main structural feature for triggering their anti-HIV activity.

O'nil Anteversa® mini-plate for stable hip fracture: first experience considerations and outcomes

Hip fractures are associated with a 20% one-year mortality and a 50% loss of function. Over 700,000 deaths are estimated to occur annually worldwide following hip fractures. Concern exist regarding which is the best implant for extracapsular fractures fixation. For a correct positioning of the cephalic screw, a new plate (O'Nil Anteversa® mini-plate, Intrauma, Torino, Italy) with a fixed 8°of anteversion in the axial plane was developed. A total of 22 patients with an intertrochanteric fracture underwent surgery with Anteversa® mini-plate between October 2016 and April 2017. Data collected included patients' age at surgery, gender, fracture type, operative side, surgeon, type of implant, TAD, CalTAD and TADCalTAD. All patients underwent clinical and radiographic evaluations according to the AO Surgery Reference classification. The mean TAD, CalTAD and TADcalTAD for the entire population of study were, respectively, 20.18±7.5 mm, 20.45±7.25 mm, and 40.62±14.44 mm. The mean TAD, CalTAD and TADcalTAD of those patients who experienced mobilisation of the cephalic screw were, respectively, 20.26±5.87 mm, 19.53±5.47 mm, and 39.8±11.16 mm. Three patients experienced mobilisation of the cephalic screw, and none of these had a TAD greater than 25 mm, a CalTAD greater of 25mm or a TADcalTAD greater than 50 mm. This type of device meets the essential requirements for a correct treatment of intertrochanteric fractures in elderly patients. However, the excessive need of attention in each step, and the consequent increased time of surgery, could be seen as a limitation for its use.

Anti-tumour effect of low molecular weight heparin in localised lung cancer: a phase III clinical trial

The anti-tumour and anti-metastatic properties of heparins have not been tested in patients with early stage cancer. Whether adjuvant low molecular weight heparin (LMWH) tinzaparin impacts the survival of patients with resected non-small cell lung cancer (NSCLC) was investigated.

Patients with completely resected stage I, II or IIIA NSCLC were randomly allocated to receive subcutaneous tinzaparin 100 IU·kg−1 once a day for 12 weeks or no treatment in addition to standard of care. The trial was open-label with blinded central adjudication of study outcomes. The primary outcome was overall survival.

In 549 patients randomised to tinzaparin (n=269) or control (n=280), mean±sd age was 61.6±8.9 years, 190 (34.6%) patients had stage II−III disease, and 220 (40.1%) patients received adjuvant chemotherapy. Median follow-up was 5.7 years. There was no significant difference in overall survival between groups (hazard ratio (HR) 1.24, 95% CI 0.92–1.68; p=0.17). There was no difference in the cumulative incidence of recurrence between groups (subdistribution HR 0.94, 95% CI 0.68–1.30; p=0.70).

Adjuvant tinzaparin had no detectable impact on overall and recurrence-free survival of patients with completely resected stage I−IIIA NSCLC. These results do not support further clinical evaluation of LMWHs as anti-tumour agents.

Stabilization vs. destabilization of G-quadruplex superstructures: the role of the porphyrin derivative having spermine arms

The interaction of the porphyrin derivative H₂TCPPSpm4, having spermine pendants in the four meso positions, with the G-quadruplex (GQ) structure formed by the DNA aptamer TGGGAG has been investigated by means of UV, electronic circular dichroism and PAGE studies. The results reported here demonstrate that the porphyrin derivative is capable of stabilizing or destabilizing the higher-ordered structures of parallel GQs, depending on the method used to reach their relative stoichiometry (titration vs. single addition). Noteworthily, when two equivalents of H₂TCPPSpm4 were mixed directly with one equivalent of the (TGGGAG)₄ GQ to reach a 2 : 1 H₂TCPPSpm4 : GQ ratio T_1/2 higher than 80 °C was also observed confirming the presence of higher-ordered GQ structures.

miR302 regulates SNAI1 expression to control mesangial cell plasticity

Cell fate decisions are controlled by the interplay of transcription factors and epigenetic modifiers, which together determine cellular identity. Here we elaborate on the role of miR302 in the regulation of cell plasticity. Overexpression of miR302 effected silencing of the TGFβ type II receptor and facilitated plasticity in a manner distinct from pluripotency, characterized by increased expression of Snail. miR302 overexpressing mesangial cells also exhibited enhanced expression of EZH2 coincident with Snail upregulation. esiRNA silencing of each component suggest that Smad3 and EZH2 are part of a complex that regulates plasticity and that miR302 regulates EZH2 and Snail independently. Subsequent manipulation of miR302 overexpressing cells demonstrated the potential of using this approach for reprogramming as evidenced by de novo expression of the tight junction components ZO-1 and E-cadherin and the formation of ZO-1 containing tight junctions. Understanding the processes through which dynamic epigenetic silencing is controlled in adults cells will allow us to address the epigenetic state of acquired disease and whether original states, regenerative in nature, can be restored with therapy.

Management of malignant pleural mesothelioma: a French multicenter retrospective study (GFPC 0802 study)

BACKGROUND

Malignant pleural mesothelioma (MPM) is a rare disease with poor prognosis in spite of significant improvement in survival, due to new chemotherapy regimens. We describe here patients' profiles and management in daily practice in France.

METHODS

Observational retrospective study. Data were collected from medical files. All patients with histologically proven MPM diagnosed from January 2005 to December 2008 were included in the participating sites.

RESULTS

Four hundred and six patients were included in 37 sites: mean age 68.9 ± 9.8 years, male predominance (sex ratio 3.27), latency of the disease 45.7 years, epithelioïd type 83 %. Diagnosis was made using thoracoscopy in 80.8 % of patients. Radical surgery was performed in 6.2 % of cases. Chemotherapy was administered to 74.6 % of patients. First line regimens consisted mainly of platinum + pemetrexed (91 %) or pemetrexed alone (7 %). Objective response rate was 17.2 % and another 41.6 % of patients experienced disease stabilization. Half of these patients underwent second line chemotherapy (platinium + pemetrexed 31.6 %, pemetrexed alone 24.6 %), resulting in a 6 % response rate. Third-line chemotherapy (56 patients) yielded disease control in 5.4 % of cases.

CONCLUSIONS

The management of MPM in France is usually in accordance with guidelines. Response rates are somewhat lower than those described in clinical trials.

Erlotinib versus carboplatin and paclitaxel in advanced lepidic adenocarcinoma: IFCT-0504

The IFCT-0504 phase II trial evaluated the efficacy of erlotinib versus carboplatin-paclitaxel (CP) as first-line treatment in 130 cases of advanced lepidic-predominant adenocarcinoma (ADC).The primary objective of the study was treatment efficacy, evaluated based on an end-point of disease control at 16 weeks.The primary objective was met, with a disease control in 35 (53%) out of 66 patients treated with CP and in 25 (39.1%) out of 64 patients treated with erlotinib. Median progression-free survival (PFS) for the total population was 3.6 months. The disease control rate did not differ between either the therapeutic arms or pathological subtypes, whereas there was a strong interaction between treatment arms and tumour pathological subtypes for PFS (p=0.009). Mucinous tumour patients treated with erlotinib exhibited an increased progression risk (hazard ratio 3.4, 95% CI 1.7-6.5; p≤0.001). The PFS for nonmucinous tumour patients was similar in both arms. Median overall survival was 20.1 months and did not differ between therapeutic arms. These findings were not further elucidated by molecular analyses and the toxicity profiles were as expected.Our study demonstrated the dominant role of CP alongside erlotinib in the management of advanced lepidic ADC. Based on these findings, erlotinib should not be administered in first-line therapy to patients with lepidic ADC in the absence of an epidermal growth factor receptor mutation.

Outstanding effects on antithrombin activity of modified TBA diastereomers containing an optically pure acyclic nucleotide analogue

Herein, we report optically pure modified acyclic nucleosides as ideal probes for aptamer modification. These new monomers offer unique advantages in exploring the role played in thrombin inhibition by a single residue modification at key positions of the TBA structure.

Two biomarker-directed randomized trials in European and Chinese patients with nonsmall-cell lung cancer: the BRCA1-RAP80 Expression Customization (BREC) studies

BACKGROUND

In a Spanish Lung Cancer Group (SLCG) phase II trial, the combination of BRCA1 and receptor-associated protein 80 (RAP80) expression was significantly associated with outcome in Caucasian patients with nonsmall-cell lung cancer (NSCLC). The SLCG therefore undertook an industry-independent collaborative randomized phase III trial comparing nonselected cisplatin-based chemotherapy with therapy customized according to BRCA1/RAP80 expression. An analogous randomized phase II trial was carried out in China under the auspices of the SLCG to evaluate the effect of BRCA1/RAP80 expression in Asian patients.

PATIENTS AND METHODS

Eligibility criteria included stage IIIB-IV NSCLC and sufficient tumor specimen for molecular analysis. Randomization to the control or experimental arm was 1 : 1 in the SLCG trial and 1 : 3 in the Chinese trial. In both trials, patients in the control arm received docetaxel/cisplatin; in the experimental arm, patients with low RAP80 expression received gemcitabine/cisplatin, those with intermediate/high RAP80 expression and low/intermediate BRCA1 expression received docetaxel/cisplatin, and those with intermediate/high RAP80 expression and high BRCA1 expression received docetaxel alone. The primary end point was progression-free survival (PFS).

RESULTS

Two hundred and seventy-nine patients in the SLCG trial and 124 in the Chinese trial were assessable for PFS. PFS in the control and experimental arms in the SLCG trial was 5.49 and 4.38 months, respectively [log rank P = 0.07; hazard ratio (HR) 1.28; P = 0.03]. In the Chinese trial, PFS was 4.74 and 3.78 months, respectively (log rank P = 0.82; HR 0.95; P = 0.82).

CONCLUSION

Accrual was prematurely closed on the SLCG trial due to the absence of clinical benefit in the experimental over the control arm. However, the BREC studies provide proof of concept that an international, nonindustry, biomarker-directed trial is feasible. Thanks to the groundwork laid by these studies, we expect that ongoing further research on alternative biomarkers to elucidate DNA repair mechanisms will help define novel therapeutic approaches.

TRIAL REGISTRATION

NCT00617656/GECP-BREC and ChiCTR-TRC-12001860/BREC-CHINA.

Prospective screening for ALK: clinical features and outcome according to ALK status

The aim of this study was to analyse the clinico-pathological characteristics and outcomes of a cohort of French patients who were prospectively screened for Anaplastic Lymphoma Kinase (ALK) rearrangement. One hundred and sixteen consecutive patients screened for ALK rearrangement to be recruited into a crizotinib registration trial were included from eight French centres. ALK rearrangement was detected by fluorescence in situ hybridization. Seventeen patients (14.6%) were positive for ALK. ALK+ patients were younger (p = 0.049) and more likely to be males (p=0.032), non- or light-smokers (p = 0.048) and without underlying respiratory disease (p=0.025) compared to ALK- patients. Thyroid-transcription factor-1 expression was present in all ALK+ tumours. ALK+ tumours tended to have lymph node and brain metastases. In multivariate analyses, gender, smoking history and N stage were independently associated with ALK status. Median overall survival (OS) was not reached for ALK+ patients and was significantly longer than for ALK- patients (hazard ratio for death for ALK- patients 2.98; 95% CI [1.29-6.90], p=0.01). French ALK+ patients present a specific phenotype. ALK rearrangement should be determined to improve OS with an effective targeted therapy.

Studies on the influence of inversion of polarity sites on the dG residues glycosidic conformation in quadruplex structures

Insights into the influence of inversion of polarity sites on the dG residues glycosidic conformation in quadruplexes is presented. The NMR studies concern modified oligodeoxynucleotides based on the quadruplex forming sequence TGGGT.

A topological classification of G-quadruplex structures

A topological classification of most quadruplex structures is proposed, based on two main characteristics: 1) the relative orientation of the strands and 2) the nature of the loops connecting the strands.

[Splenic metastasis from a bronchial carcinoma]

INTRODUCTION

Isolated splenic metastases from a bronchial carcinoma, without other visceral metastatic involvement, are exceptionally uncommon.

CASE REPORT

The authors report the finding of an isolated splenic metastasis 21 months after a left pneumonectomy for an undifferentiated large cell carcinoma, initially staged pT3N1M0. The splenic metastasis presented as a major deterioration in general health and sharp pains in the left hypochondrium. Splenectomy confirmed the metastatic nature of the splenic tumour and relieved the severe abdominal pains. Two years after the splenectomy and with out adjuvant treatment the patient remains in complete remission.

CONCLUSION

Splenectomy for a metastasis from a bronchial carcinoma should avoid the later complications of this type of metastasis: severe abdominal pain, splenic rupture and compression of neighbouring vessels. If the bronchial carcinoma is controlled locally and the splenic metastasis is isolated, splenectomy offers, perhaps, a further chance of prolonged survival.

[Choroidal metastases in lung cancer]

INTRODUCTION

Ocular metastases are rare and their diagnosis can be difficult, being dependent on a combination of clinical examination of the eye, ultrasound, angiography and magnetic resonance imaging.

CLINICAL CASE

We describe two cases of cases of choroidal metastases in patients with a bronchogenic carcinoma. In both cases the metastases presented at a late stage in the disease and occurred in association with cerebral metastases. One patient had an epidermoid tumour the other a small cell carcinoma. Loss of visual acuity, which was slowly progressive in the first case and abrupt in the second, led to the diagnosis of choroidal metastases. Following radiotherapy in a dose of 30 Gray delivered to the posterior segment of the eye, both patients' visual acuity recovered to near normal within a few weeks.

CONCLUSION

If patients with lung cancer develop visual disturbance the possibility of choroidal metastases should be considered. Ocular radiotherapy can often ameliorate disabling visual disturbance, significantly improving quality of life.

Synthesis of 5-methylamino-2'-deoxyuridine derivatives

Reductive amination of 3',5'-O-(tetraisopropyldisilyloxane-1,3-diyl)-2'-deoxy-5-formyluridine with several aliphatic and aromatic amines, in various solvents, is described. In the case of aliphatic amines, the expected C-5 substituted methylamino pyrimidine nucleosides are formed along with by-products deriving from opening of the pyrimidine ring. Relative amounts of the by-products depend upon the polarity of the solvent employed.

Solid-phase synthesis of oligonucleotides containing a bipyridine ligand at the 3'-3' inversion of polarity site

The preparation of a solid support useful for the synthesis of oligonucleotides with a 3'-3' inversion of polarity, via a linker containing a chelating molecule, namely 2,2'-bipyridine, is described.

[Pulmonary lymphangioleiomyomatosis in a menopaused woman]

We report an unusual case of pulmonary lymphangioleiomyomatosis in a menopaused woman who had been taking estrogen hormone replacement therapy for several years. The characteristic feature of this uncommon disease is a proliferation of non-tumoral abnormal smooth muscle cells within the alveolar walls, and around the bronchi, lymph nodes and blood vessels. About twenty cases of pulmonary lymphangioleiomyomatosis have been described in menopaused women, who generally were taking estrogen hormone replacement therapy. This subpopulation does not appear to present any particular clinical, functional or radiographic features.

Use of automated solid-phase extraction equipment for the determination of isoniazid in milk

The possibility of using automated equipment for solid phase extraction of isoniazid from milk has been investigated. This equipment provides two noteworthy advantages: it shortens the time of analysis and avoids SPE column plugging, stabilizing flow rates. After setting the correct programme on software controlling the equipment, some validation parameters have been determined to obtain recovery and repeatability data. The mean recovery for spiked samples resulted in the range 75-95%, the standard error ranged from -5 to -20% while the RSD varied from 2 to 22%. Therefore the method can be considered reliable and fast.

Use of automated solid-phase extraction equipment for the determination of ivermectin residues in animal liver by HPLC

An improvement of the method commonly used for the determination of ivermectin is proposed. An automatic system is used for the solid-phase extraction column purification stage in order to provide more efficient and fast sample preparation, prior to separation and quantification by HPLC. Some tests were performed to obtain recovery and repeatability data. The mean recovery for spiked samples (five replicates twice at three concentration levels) was more than 90% in the concentration range 7.5-30 ng g-1. The tests for accuracy (five replicates at three concentration levels) gave a standard error of -2.0% at the highest and -19.2% at the lowest concentration. Concerning repeatability data (five replicates twice at three concentration levels), in the concentration range 7.5-30 ng g-1 the RSD varied from 9.29 to 2.15%. The described method was used in a survey on the presence of ivermectin in food-producing animals in two regions of southern Italy; no positives out of 250 liver samples were found.

Clenbuterol residues in non-liver containing meat as a cause of collective food poisoning

beta 2-adrenergic agonists, particularly clenbuterol, are illegally used as growth promoters to obtain lean in meat. Their administration in feedlots can constitute a severe risk for animal welfare and exposes consumers to involuntary drug consumption at pharmacological active concentrations. Reported poisoning episodes have been associated with the consumption of beef liver where clenbuterol residues concentrate. In August 1996, 62 persons asked for medical help at the emergency rooms of 2 hospitals near the city of Caserta (Italy). Their clinical profile was characteristic of previously occurring clenbuterol intoxication, which reported superventricular extrasystoles and atrial fibrillation. All patients had non-liver beef meat consumption 10-30 min to 2-3 h before symptoms developed. An ELISA screening test specific for clenbuterol confirmed the drug's presence. Definitive confirmation of clenbuterol and determination of the drug content in meat samples were obtained by GC-MS, using 2 different derivatization. Concentrations in the meats ranged from 0.8 to 7.4 mg/kg. These analytical data provided evidence of the seriousness of the poisoning and helped the National Health System identify other possible misinterpreted cases. This case demonstrates that clenbuterol poisoning can also occur after consumption of beef meat other than liver.

Polychlorinated biphenyls and dichlorodiphenyl trichloroethane in human milk. A review

Polychlorinated biphenyls (PCBs) and dichlorodiphenyl trichloroethane (DDT) are the most frequent chemical contaminants present in human milk. Factors involving the levels of PCBs and DDT in human milk are revised. Allowable daily intake of both contaminants is indicated as well as their effect on human exposure are discussed. Since available data suggest that these contaminants are available for redistribution to the lactating mammary gland, we stress the importance of a dietary regimen to breast fed mothers in order to prevent the mobilization of body fat stores for milk fat synthesis.