Simplex Droplet Digital PCR Assays for the Detection of TERT Promoter Mutations in Urine Samples for the Non-invasive Diagnosis of Urothelial Cancer

Somatic mutations in the telomerase reverse transcriptase (TERT) promoter region are highly frequent in urothelial cancer (UC), and their detection in urine (cell-free DNA from the urine supernatant or DNA from exfoliated cells in the urine pellet) has demonstrated promising evidence as putative non-invasive biomarkers for UC detection and monitoring. However, detecting these tumour-derived mutations in urine requires highly sensitive methods, capable of measuring low-allelic fraction mutations. We developed sensitive droplet digital PCR (ddPCR) assays for detecting urinary TERT promoter mutations (uTERTpm), targeting the two most common mutations (C228T and C250T), as well as the rare A161C, C228A, and CC242-243TT mutations. Here, we described the step-by-step protocol uTERTpm mutation screening using simplex ddPCR assays and give some recommendations for isolation of DNA from urine samples. We also provide limits of detection for the two most frequent mutations and discuss advantages of the method for clinical implementation of the assays for the detection and monitoring of UC.

TERT Promoter Mutations as Simple and Non-Invasive Urinary Biomarkers for the Detection of Urothelial Bladder Cancer in a High-Risk Region

Bladder cancer (BC) is the 10th most common cancer in the world. While there are FDA-approved urinary assays to detect BC, none have demonstrated sufficient sensitivity and specificity to be integrated into clinical practice. Telomerase Reverse Transcriptase (TERT) gene mutations have been identified as the most common BC mutations that could potentially be used as non-invasive urinary biomarkers to detect BC. This study aims to evaluate the validity of these tests to detect BC in the Kerman province of Iran, where BC is the most common cancer in men. Urine samples of 31 patients with primary (n = 11) or recurrent (n = 20) bladder tumor and 50 controls were prospectively collected. Total urinary DNA was screened for the TERT promoter mutations (uTERTpm) by Droplet Digital PCR (ddPCR) assays. The performance characteristics of uTERTpm and the influence by disease stage and grade were compared to urine cytology results. The uTERTpm was 100% sensitive and 88% specific to detect primary BC, while it was 50% sensitive and 88% specific in detecting recurrent BC. The overall sensitivity and specificity of uTERTpm to detect bladder cancer were 67.7% and 88.0%, respectively, which were consistent across different tumor stages and grades. The most frequent uTERTpm mutations among BC cases were C228T (18/31), C250T (4/31), and C158A (1/31) with mutant allelic frequency (MAF) ranging from 0.2% to 63.3%. Urine cytology demonstrated a similar sensitivity (67.7%), but lower specificity (62.0%) than uTERTpm in detecting BC. Combined uTERTpm and urine cytology increased the sensitivity to 83.8%, but decreased the specificity to 52.0%. Our study demonstrated promising diagnostic accuracy for the uTERTpm as a non-invasive urinary biomarker to detect, in particular, primary BC in this population.

The monomeric C-reactive protein level is associated with the increase in carotid plaque number in patients with subclinical carotid atherosclerosis

The high-sensitivity C-reactive protein (hsCRP) assay measures the level of the pentameric form of CRP in blood. Currently, there are no available assays measuring the level of the monomeric form of CRP (mCRP), produced at sites of local inflammation. We developed an assay measuring the mCRP level in blood plasma with functional beads for flow cytometry. The assay was used to measure the mCRP level in 80 middle-aged individuals with initially moderate cardiovascular SCORE risk. By the time of the mCRP measurement, the patients have been followed up for subclinical carotid atherosclerosis progression for 7 years. Ultrasound markers of subclinical atherosclerosis, which included plaque number (PN) and total plaque height (PH), were measured at baseline and at the 7th-year follow-up survey. Inflammatory biomarkers, including mCRP, hsCRP, inteleukin-6 (IL-6) and von Willebrand factor (VWF) level, were measured at the 7th-year follow-up survey. The median level of mCRP was 5.2 (3.3; 7.1) μg/L, hsCRP 1.05 (0.7; 2.1) mg/L, IL-6 0.0 (0.0; 2.8) pg/mL, VWF 106 (77; 151) IU/dL. In the patients with the mCRP level below median vs. the patients with the median mCRP level or higher, change from baseline in PN was 0.0 (0.0; 1.0) vs. 1.0 (1.0; 2.0) and PH 0.22 (−0.24; 1.91) mm vs. 1.97 (1.14; 3.14) mm, respectively (p < 0.05). The adjusted odds ratio for the formation of new carotid atherosclerotic plaques was 4.7 (95% CI 1.7; 13.2) for the patients with the median mCRP level or higher. The higher mCRP level is associated with the more pronounced increase in PN and PH in patients with normal level of traditional inflammatory biomarkers and initially moderate cardiovascular SCORE risk.

Efficiency of voluntary auditory-speech memory in younger schoolchildren with different types of dysontogenesis

Introduction

Assessing of voluntary auditory verbal memory, mediated or non-mediated by meaning context is an important component of impaired mental or psychic development estimation in children with different types of dysontogenesis.

Objectives

Investigation of memory in chidren with mental disorders

Methods

Participants: Children 9-12 years: ND - 25 normal development (14 boys), F70 - 31 with mild mental retardation (18 boys), F20.8 - 15 children with childhood type of schizophrenia (11 boys) and F21- 29 with schizotypal disorder (22 boys). Learning of 10 words, simple (SPA) and complex (CPA) paired associations. Assessing Parameter - auditory-speech memory efficiency in each of techniques. Mann-Whitney criterion.

Results

There were significant differences in memory efficiency of 10 words between F21 and F70 (p≤0.01) and F70 and F20.8 (p≤0.05). Simple paired associations - no differences between all groups. Complex paired associations: F21 and F70 (p≤0.05), F21 and F20.8 (p≤0.01). ND - significant differences in memory efficiency of 10 words with all groups (F21 – p ≤0.01, F20.8 – p ≤0.05, F70 – p ≤0.01). SPA: significant differences with all groups (p≤ 0.01). CPA - significant differences words with all groups (F21 – p≤ 0.05, F20.8 – p≤ 0.01, F70 – p ≤0.01).

Conclusions

Сommon features of working memory in children with diseased type of development:- improved memorization with introduction of strong semantic connections for all types of dysontogenesis. For complex connections in different groups we suppose different mechanisms of destroyed memory: F70 - low level of thinking, F20.8 - decreasing in mental activity or as a result of forming defect.

Disclosure

No significant relationships.

Recognition of emotional and expressive movements (gestures) and self-esteem of adolescents with affective disorders

Introduction

Successful adolescence depends on ability to correctly understand emotionally expressive gestures, especially symbolic (same meaning for everyone) and expressive (individual understanding). Presence of an internal mismatch in adolescent’s self-esteem between what he shows in society and what he really feels can lead to difficulties in forming an adequate adult self-esteem.

Objectives

Adolescents with affective disorders (F31) -12, normal adolescents - 32. Ages 12-17.

Methods

Recognition of emotionally expressive movements: postures&gestures (gestures-test), direct self-esteem by Dembo-Rubinstein test and indirect self-esteem by color attitude test by Etkind.

Results

The Mann-Whitney test showed significant differences between samples in terms of self-esteem gap - “mind” (U=270,000, p<0.37), “character” (U=279,000, p<0.20), “happiness” (U=288,000, p<0.01 ), gestures-test “symbolic” (U=301,000, p<0.003), “expressive” (U=292,000, p<0.007), “emotions” (U=109,000, p<0.028). Cluster analysis divided each of groups into two distinct clusters. Normal: Cluster1 small self-esteem gap, good gesture recognition, negative pole of emotions prevails. Cluster2 small self-esteem gap, worse gesture recognition, pole of emotions is closer to positive. Affective: Cluster1 large self-esteem gap in “mind”, good gesture recognition. Cluster2 large self-esteem gap in “character”, good gesture recognition and bright negative pole of emotions.

Conclusions

Gestures recognition in normal group is significantly higher than in affective disorder group. Normal adolescents clusters are distinguished by change in gaps throughout self-esteem and pole of emotional recognition. Affective disorder clusters differ by significant gap in one of self-esteem parameters, as well as in the degree of emotional recognition. Those with the largest “character” gap are more likely to attribute negative emotions to gestures than those with larger “mind” gap.

Disclosure

No significant relationships.

Detection of TERT Promoter Mutations as a Prognostic Biomarker in Gliomas: Methodology, Prospects, and Advances

This article reviews the existing approaches to determining the TERT promoter mutational status in patients with various tumoral diseases of the central nervous system. The operational characteristics of the most common methods and their transferability in medical practice for the selection or monitoring of personalized treatments based on the TERT status and other related molecular biomarkers in patients with the most common tumors, such as glioblastoma, oligodendroglioma, and astrocytoma, are compared. The inclusion of new molecular markers in the course of CNS clinical management requires their rapid and reliable assessment. Availability of molecular evaluation of gliomas facilitates timely decisions regarding patient follow-up with the selection of the most appropriate treatment protocols. Significant progress in the inclusion of molecular biomarkers for their subsequent clinical application has been made since 2016 when the WHO CNS classification first used molecular markers to classify gliomas. In this review, we consider the methodological approaches used to determine mutations in the promoter region of the TERT gene in tumors of the central nervous system. In addition to classical molecular genetical methods, other methods for determining TERT mutations based on mass spectrometry, magnetic resonance imaging, next-generation sequencing, and nanopore sequencing are reviewed with an assessment of advantages and disadvantages. Beyond that, noninvasive diagnostic methods based on the determination of the mutational status of the TERT promoter are discussed.

Glycosylation of Receptor Binding Domain of SARS-CoV-2 S-Protein Influences on Binding to Immobilized DNA Aptamers

Nucleic acid aptamers specific to S-protein and its receptor binding domain (RBD) of SARS-CoV-2 (severe acute respiratory syndrome-related coronavirus 2) virions are of high interest as potential inhibitors of viral infection and recognizing elements in biosensors. Development of specific therapy and biosensors is complicated by an emergence of new viral strains bearing amino acid substitutions and probable differences in glycosylation sites. Here, we studied affinity of a set of aptamers to two Wuhan-type RBD of S-protein expressed in Chinese hamster ovary cell line and Pichia pastoris that differ in glycosylation patterns. The expression system for the RBD protein has significant effects, both on values of dissociation constants and relative efficacy of the aptamer binding. We propose glycosylation of the RBD as the main force for observed differences. Moreover, affinity of a several aptamers was affected by a site of biotinylation. Thus, the robustness of modified aptamers toward new virus variants should be carefully tested.

Urine TERT promoter mutations-based tumor DNA detection in patients with bladder cancer: A pilot study

Telomerase reverse transcriptase (TERT) promoter mutations are the most frequent genetic events in bladder cancer (BC). The aim of the present pilot study was to evaluate the diagnostic potential of urine TERT promoter mutations-based liquid biopsy in patients with an ongoing oncological process, as well as in post-resection patients at risk of BC recurrence. A total of 60 patients were enrolled, of whom 27 patients had histologically proven BC; 23 had no signs of BC (control group); and 10 patients underwent transurethral malignancy resection 3-6 months prior to urine donation ('second look' group). Urine TERT promoter mutations were detected using Droplet Digital PCR. Receiver operating characteristic curve analysis revealed significant diagnostic power of the present approach (area under the curve: -0.768). At the cut-off value of tumor DNA fraction 0.34%, the sensitivity and specificity were 55.56 and 100%, respectively. In the positive samples, tumor DNA fraction varied significantly from 0.59 to 48.77%. In the 'second look' group, tumor DNA was detected in 4/10 patients, highlighting the possibility of BC recurrence with its fraction ranging only from 0.90 to 6.61%. Therefore, urine TERT promoter mutations-based liquid biopsy appears to be a promising tool for BC diagnosis and surveillance. The main study will include recruitment of additional patients, extension of the mutation panel, prolonged follow-up of the post-resection patients, as well as screening of industrial workers exposed to specific carcinogens.

Psychological assessment of the cognitive development of children with IVF: The experience of neuropsychological approach

Introduction

The first stage of interdisciplinary studying (EEG, IQ, immunology, psychology, neuropsychology) of cognitive development of children with IVF, conducting at the Mental Health Research Center (Moscow, Russia) is presenting. A small number of studies analyzing the cognitive development of children in a wide age range, determined the design of this study.

Objectives

Assessment of the capabilities of the neuropsychological approach in qualifying the cognitive development of children with IVF.

Methods

20 children aged 7 to 15 years old, born with IVF, studying in school. Neuropsychological diagnosis according to A.R. Luria-L.S.Tsvetkova. All participants signed voluntary consent to participate in the study.

Results

1. Neuropsychological approach and methods of neuropsychological diagnostics are effective in qualifying the neurocognitive development of children with IVF 2. The overwhelming majority of the examined children (90%) had energy factor dysfunction (at the level of brain stem structures in 65%, at the level of diencephalic structures in 82%, combined disorders at both levels in 52%) 3. Regulatory inhibitory control (impulse control - suppression of the dominant reaction) was impaired (functionally unformed) in 58% of the subjects 4. A gross violation of the kinetic factor was found in 46% of the examined children and adolescents IVF 5. The development of speech and visual memory is variable.

Conclusions

The conclusions are preliminary and require testing on a wider sample of children born because of IVF and other assisted reproductive technologies. It is necessary to study the functional state of other neuropsychological factors, to expand the number of participants.

Features of interconnection between temperament, self-esteem and aggressiveness in adolescents with mental and somatic pathology

Introduction

Adolescence can manifest different in norm and in illness. It’s important to find common characteristics of adaptation with different types of ontogenesis, or leading manifestations of disease

Objectives

Three adolescence (boys&girls) sample: normal – 22, middle age 16, cardio pathology – 7, middle age 16, psychopathology – 12, middle age 15

Methods

Direct self-esteem by Dembo-Rubinstein (DR) test and indirect self-esteem by color attitude test by Etkind (CAT), Structure of Temperament Questionnaire (STQ-77), Buss-Perry Aggression Questionnaire (BPAQ).

Results

Significant differences (criteria Kruskal–Wallis) were obtained on scales BRAQ “Hostility” (H= 8.430, p<0.015), “Common aggression” (H= 8.347, p<0.015), STQ-77 “Physical Endurance” (H= 9.895, p<0.007), “Physical Tempo” (H= 8.579, p<0.014), “Social Endurance” (H= 7.902, p<0.019), “Social Tempo” (H= 7.736, p<0.021), “Plasticity” (H= 7.797, p<0.020), “Self-confidence” (H= 7.157, p<0.028), “Neuroticism” (H= 8.179, p<0.017); gaps DR-CAT for scales “Health” (H= 12.330, p<0.002), “Happiness” (H= 7.296, p<0.026). Pearson correlation coefficient between STQ-77, BRAQ and Gaps DR-CAT found in normal group: Gap DR-CAT “Health” – STQ-77 “Physical Endurance” (r=-.508, p<0.05), Gap DR-CAT “Smart” - STQ-77 “Intellectual Endurance” (r=-.521, P<0.05), Gap DR-CAT “Happiness” – BRAQ “Hostility” (r=.528, p<0.05), Gap DR-CAT “Happiness” - STQ-77 “Impulsivity” (r=.432, p<0.05), “Neuroticism” (r=.539,p<0.01). Correlation was founded in cardio pathology group: Gap DR-CAT “Smart” – BRAQ “Physical aggression” (r=.857, p<0.05), “Anger” (r=.842,p<0.05), “Common aggression” (r=.860,p<0.05), Gap DR-CAT “Happiness” – BRAQ “Physical aggression” (r=.826,p<0.05), “Anger” (r=.773,p<0.05), “Common Aggression” (r=.787,p<0.05). For psychopathology wasn’t found correlations.

Conclusions

Comparative study of personality traits of adolescents with different types of ontogenesis (normotypical, mental, cardio pathology) is important for evaluating their adaptation and determining targets of psychotherapeutic work.

Case of psychological consultation and observation an adolescent with dissociative dysmnesia

Introduction

Cases of memory loss are rare phenomena. We present a case-study of common psychological and psychotherapy observation 14,5 years old girl with dissociative dysmnesia during 2 years. Teenager grew up in a small town near Moscow, her parents were divorced. A girl and her elder brother stay with mother. One day in New Year Holiday in January she had come to take out the trash and did not return home. When mother and her friends had found girl on the other side of town, she did not remember anything about her life and family. Goal: description the case of long observing adolescent with dissociative dysmnesia

Objectives

Girl age 14,5 y.o.

Methods

Psychodiagnostics, Psychotherapy.

Results

First period (1 months later initial episode) mother provided mane consultations to understand what has happened with daughter and what is illness. Psychiatrist made a diagnosis - dissociative dysmnesia, neurologists did not find any disturbances. Psychological diagnostics showed small gaps in knowledge, pronounced violations of autobiographical memory, decreased activity, and mood. Unusual results were obtained in projective drawing. She got to know her family and friends again, started an account on Internet, shares her stories. These 2 years she worked with individual psychotherapist with positive changes. In September 2020 she went to school, not yet caught up with program. She masters the guitar, continues to play in the theater studio, and makes plans for future.

Conclusions

After 2 year observation and work autobiographical memory has not restored. Girl’s personality hasn’t changed, according to the family. Her mood and communication look better.

Disclosure

No significant relationships.

Development of Sensitive Droplet Digital PCR Assays for Detecting Urinary TERT Promoter Mutations as Non-Invasive Biomarkers for Detection of Urothelial Cancer

Somatic mutations in the telomerase reverse transcriptase (TERT) promoter regions are frequent events in urothelial cancer (UC) and their detection in urine (supernatant cell-free DNA or DNA from exfoliated cells) could serve as putative non-invasive biomarkers for UC detection and monitoring. However, detecting these tumor-borne mutations in urine requires highly sensitive methods, capable of measuring low-level mutations. In this study, we developed sensitive droplet digital PCR (ddPCR) assays for detecting TERT promoter mutations (C228T, C228A, CC242-243TT, and C250T). We tested the C228T and C250T ddPCR assays on all samples with sufficient quantity of urinary DNA (urine supernatant cell-free DNA (US cfDNA) or urine pellet cellular DNA (UP cellDNA)) from the DIAGURO (n = 89/93 cases and n = 92/94 controls) and from the IPO-PORTO (n = 49/50 cases and n = 50/50 controls) series that were previously screened with the UroMuTERT assay and compared the performance of the two approaches. In the DIAGURO series, the sensitivity and specificity of the ddPCR assays for detecting UC using either US cfDNA or UP cellDNA were 86.8% and 92.4%. The sensitivity was slightly higher than that of the UroMuTERT assay in the IPO-PORTO series (67.4% vs. 65.3%, respectively), but not in the DIAGURO series (86.8% vs. 90.7%). The specificity was 100% in the IPO-PORTO controls for both the UroMuTERT and ddPCR assays, whereas in the DIAGURO series, the specificity dropped for ddPCR (92.4% versus 95.6%). Overall, an almost perfect agreement between the two methods was observed for both US cfDNA (n = 164; kappa coefficient of 0.91) and UP cellDNA (n = 280; kappa coefficient of 0.94). In a large independent series of serial urine samples from DIAGURO follow-up BC cases (n = 394), the agreement between ddPCR and UroMuTERT was (i) strong (kappa coefficient of 0.87), regardless of urine DNA types (kappa coefficient 0.89 for US cfDNA and 0.85 for UP cellDNA), (ii) the highest for samples with mutant allelic fractions (MAFs) > 2% (kappa coefficient of 0.99) and (iii) only minimal for the samples with the lowest MAFs (< 0.5%; kappa coefficient 0.32). Altogether, our results indicate that the two methods (ddPCR and UroMuTERT) for detecting urinary TERT promoter mutations are comparable and that the discrepancies relate to the detection of low-allelic fraction mutations. The simplicity of the ddPCR assays makes them suitable for implementation in clinical settings.

PHARMACEUTICAL PROVISION AND PHYSICAL ACTIVITY FOR SUPPORTING WORKING CAPACITY OF MILITARY AND SECURITY SERVICES

Aim. The paper aims to explore the effect of Trekrezan on working capacity, psychosomatic status, and hemodynamic parameters of military and security personnel, as well as the possibility to increase its psychological tolerance to stress. Materials and methods. 52 men participated in the study with the average age of 35.4 ± 6.6 years. The participants had been taking Trekrezan in tablets at a dose of 600 mg/day for 3 months. Duplex scanning of carotid and vertebral arteries was carried out according to the method of R. Barnes. Assessment of psychological and somatic status was carried out by the Hamilton test. Physical activity was tested by standard exercises (volunteer military service). Results. Trekrezan intake demonstrated a positive effect on anxiety and emotional stability and provided a significant increase in the maximum and average blood flow rates into common and internal carotid arteries. In 37.5% of 94.7% of men with thickening of the intima/media complex (IMT), IMT values demonstrated normalization after 3 months of taking the pills. Conclusion. Trekrezan significantly improves regional blood flow in the carotid artery system, has a positive effect on the psychosomatic status and improves life quality. Trekresan intake (600 mg / day per 3 months) increases working capacity of military and security personnel and can be recommended as a supplement that improves tolerance to physical activity.

Activating Telomerase TERT Promoter Mutations and Their Application for the Detection of Bladder Cancer

This review summarizes state-of-the-art knowledge in early-generation and novel urine biomarkers targeting the telomerase pathway for the detection and follow-up of bladder cancer (BC). The limitations of the assays detecting telomerase reactivation are discussed and the potential of transcription-activating mutations in the promoter of the TERT gene detected in the urine as promising simple non-invasive BC biomarkers is highlighted. Studies have shown good sensitivity and specificity of the urinary TERT promoter mutations in case-control studies and, more recently, in a pilot prospective cohort study, where the marker was detected up to 10 years prior to clinical diagnosis. However, large prospective cohort studies and intervention studies are required to fully validate their robustness and assess their clinical utility. Furthermore, it may be interesting to evaluate whether the clinical performance of urinary TERT promoter mutations could increase when combined with other simple urinary biomarkers. Finally, different approaches for assessment of TERT promoter mutations in urine samples are presented together with technical challenges, thus highlighting the need of careful technological validation and standardization of laboratory methods prior to translation into clinical practice.

Circulating tumour-derived KRAS mutations in pancreatic cancer cases are predominantly carried by very short fragments of cell-free DNA

BACKGROUND

The DNA released into the bloodstream by malignant tumours· called circulating tumour DNA (ctDNA), is often a small fraction of total cell-free DNA shed predominantly by hematopoietic cells and is therefore challenging to detect. Understanding the biological properties of ctDNA is key to the investigation of its clinical relevance as a non-invasive marker for cancer detection and monitoring.

METHODS

We selected 40 plasma DNA samples of pancreatic cancer cases previously reported to carry a KRAS mutation at the 'hotspot' codon 12 and re-screened the cell-free DNA using a 4-size amplicons strategy (57 bp, 79 bp, 167 bp and 218 bp) combined with ultra-deep sequencing in order to investigate whether amplicon lengths could impact on the capacity of detection of ctDNA, which in turn could provide inference of ctDNA and non-malignant cell-free DNA size distribution.

FINDINGS

Higher KRAS amplicon size (167 bp and 218 bp) was associated with lower detectable cell-free DNA mutant allelic fractions (p < 0·0001), with up to 4·6-fold (95% CI: 2·6-8·1) difference on average when comparing the 218bp- and the 57bp-amplicons. The proportion of cases with detectable KRAS mutations was also hampered with increased amplicon lengths, with only half of the cases having detectable ctDNA using the 218 bp assay relative to those detected with amplicons less than 80 bp.

INTERPRETATION

Tumour-derived mutations are carried by shorter cell-free DNA fragments than fragments of wild-type allele. Targeting short amplicons increases the sensitivity of cell-free DNA assays for pancreatic cancer and should be taken into account for optimized assay design and for evaluating their clinical performance.

FUNDING

IARC; MH CZ - DRO; MH SK; exchange program between IARC and Sao Paulo medical Sciences; French Cancer League.

Urinary TERT promoter mutations are detectable up to 10 years prior to clinical diagnosis of bladder cancer: Evidence from the Golestan Cohort Study

BACKGROUND

Detecting pre-clinical bladder cancer (BC) using urinary biomarkers may provide a valuable opportunity for screening and management. Telomerase reverse transcriptase (TERT) promoter mutations detectable in urine have emerged as promising BC biomarkers.

METHODS

We performed a nested case-control study within the population-based prospective Golestan Cohort Study (50,045 participants, followed up to 14 years) and assessed TERT promoter mutations in baseline urine samples from 38 asymptomatic individuals who subsequently developed primary BC and 152 matched controls using a Next-Generation Sequencing-based single-plex assay (UroMuTERT) and droplet digital PCR assays.

FINDINGS

Results were obtained for 30 cases and 101 controls. TERT promoter mutations were detected in 14 pre-clinical cases (sensitivity 46·67%) and none of the controls (specificity 100·00%). At an estimated BC cumulative incidence of 0·09% in the cohort, the positive and negative predictive values were 100·00% and 99·95% respectively. The mutant allelic fractions decreased with the time interval from urine collection until BC diagnosis (p = 0·033) but the mutations were detectable up to 10 years prior to clinical diagnosis.

INTERPRETATION

Our results provide the first evidence from a population-based prospective cohort study of the potential of urinary TERT promoter mutations as promising non-invasive biomarkers for early detection of BC. Further studies should validate this finding and assess their clinical utility in other longitudinal cohorts.

FUNDING

French Cancer League, World Cancer Research Fund International, Cancer Research UK, Tehran University of Medical Sciences, the International Agency for Research on Cancer, and the U.S. National Cancer Institute.

Protein encoded in human telomerase RNA is involved in cell protective pathways

Several studies have described functional peptides encoded in RNA that are considered to be noncoding. Telomerase RNA together with telomerase reverse transcriptase and regulatory proteins make up the telomerase complex, the major component of the telomere length-maintaining machinery. In contrast to protein subunits, telomerase RNA is expressed constitutively in most somatic cells where telomerase reverse transcriptase is absent. We show here that the transcript of human telomerase RNA codes a 121 amino acid protein (hTERP). The existence of hTERP was shown by immunoblotting, immunofluorescence microscopy and mass spectroscopy. Gain-of-function and loss-of-function experiments showed that hTERP protects cells from drug-induced apoptosis and participates in the processing of autophagosome. We suggest that hTERP regulates crosstalk between autophagy and apoptosis and is involved in cellular adaptation under stress conditions.

Urinary TERT promoter mutations as non-invasive biomarkers for the comprehensive detection of urothelial cancer

BACKGROUND

Recurrent mutations in the promoter of the telomerase reverse transcriptase (TERT) gene (C228T and C250T) detected in tumours and cells shed into urine of urothelial cancer (UC) patients are putative biomarkers for UC detection and monitoring. However, the possibility of detecting these mutations in cell-free circulating DNA (cfDNA) in blood and urine, or DNA from urinary exfoliated cells (cellDNA) with a single-gene sensitive assay has never been tested in a case-control setting.

METHODS

We developed a single-plex assay (UroMuTERT) for the detection of low-abundance TERT promoter mutations. We tested 93 primary and recurrent UC cases and 94 controls recruited in France (blood, urine samples and tumours for the cases), and 50 primary UC cases and 50 controls recruited in Portugal (urinary exfoliated cell samples). We compared our assay with urine cytology.

FINDINGS

In the French series, C228T or C250T were detected in urinary cfDNA or cellDNA in 81 cases (87·1%; 95% CI 78·6-93·2), and five controls (Specificity 94·7%; 95%CI 88·0-98·3), with 98·6% (95% CI 92·5-99·96) concordance in matched tumours. Detection rate in plasma cfDNA among cases was 7·1%. The UroMuTERT sensitivity was (i) highest for urinary cfDNA and cellDNA combined, (ii) consistent across primary and recurrent cases, tumour stages and grades, (iii) higher for low-risk non-muscle invasive UC (86·1%) than urine cytology (23·0%) (P < 0·0001) and (iv) 93·9% when combined with cytology. In the Portuguese series - the sensitivity and specificity for detection of UC with urinary cellDNA was 68·0% (95% CI 53·3-80·5) and 98·0% (95% CI 89·3-100·0).

INTERPRETATION

TERT promoter mutations detected by the UroMuTERT assay in urinary DNA (cfDNA or cellDNA) show excellent sensitivity and specificity for the detection of UC, significantly outperforming that of urine cytology notably for detection of low-grade early stages UC. FUND: French Cancer League; French Foster Research in Molecular Biology and European Commission FP7 Marie Curie COFUND.

Interstitial telomeric repeats-associated DNA breaks

During a cell's lifespan, DNA break formation is a common event, associated with many processes, from replication to apoptosis. Most of DNA breaks are readily repaired, but some are meant to persist in time, such as the chromosome ends, protected by telomeres. Besides them, eukaryotic genomes comprise shorter stretches of interstitial telomeric repeats. We assumed that the latter may also be associated with the formation of DNA breaks meant to persist in time. In zebrafish and mouse embryos, cells containing numerous breakage foci were identified. These breaks were not associated with apoptosis or replication, nor did they seem to activate DNA damage response machinery. Unlike short-living, accidental sparse breaks, the ones we found seem to be closely associated, forming discrete break foci. A PCR-based method was developed, allowing specific amplification of DNA regions located between inverted telomeric repeats associated with breaks. The cloning and sequencing of such DNA fragments were found to denote some specificity in their distribution for different tissue types and development stages.

TERRA mimicking ssRNAs prevail over the DNA substrate for telomerase in vitro due to interactions with the alternative binding site

Telomerase is a key component of the telomere length maintenance system in the majority of eukaryotes. Telomerase displays maximal activity in stem and cancer cells with high proliferative potential. In humans, telomerase activity is regulated by various mechanisms, including the interaction with telomere ssDNA overhangs that contain a repetitive G-rich sequence, and with noncoding RNA, Telomeric repeat-containing RNA (TERRA), that contains the same sequence. So these nucleic acids can compete for telomerase RNA templates in the cell. In this study, we have investigated the ability of different model substrates mimicking telomere DNA overhangs and TERRA RNA to compete for telomerase in vitro through a previously developed telomerase inhibitor assay. We have shown in this study that RNA oligonucleotides are better competitors for telomerase that DNA ones as RNA also use an alternative binding site on telomerase, and the presence of 2'-OH groups is significant in these interactions. In contrast to DNA, the possibility of forming intramolecular G-quadruplex structures has a minor effect for RNA binding to telomerase. Taking together our data, we propose that TERRA RNA binds better to telomerase compared with its native substrate - the 3'-end of telomere DNA overhang. As a result, some specific factor may exist that participates in switching telomerase from TERRA to the 3'-end of DNA for telomere elongation at the distinct period of a cell cycle in vivo. Copyright © 2015 John Wiley & Sons, Ltd.

Chimeric bifunctional oligonucleotides as a novel tool to invade telomerase assembly

Telomerase is a key participant in the telomere length maintaining system in eukaryotic cells. Telomerase RNA and protein reverse transcriptase subunits are essential for the appearance of active telomerase in vitro. Telomerase is active in many cancer types and is a potential target for anticancer drug development. Here we report a new approach for impairing telomerase function at the stage of human telomerase assembly. The approach is based on the application of chimeric bifunctional oligonucleotides that contain two oligonucleotide parts complementary to the functional domains of telomerase RNA connected with non-nucleotide linkers in different orientations (5'-3', 5'-5' or 3'-3'). Such chimeras inhibited telomerase in vitro in the nM range, but were effective in vivo in sub-nM concentrations, predominantly due to their effect on telomerase assembly and dimerization.

Towards structural characterization of H. polymorpha telomerase components

Telomeres are regions of non-coding DNA that cap the chromosomes, preventing the loss of coding DNA during cell division and contributing to chromosomal stability. In actively dividing cells, such as embryonic stem cells, the telomeres need to elongated by telomerase. The telomerase complex consist of the enzyme telomerase reverse transcriptase (TERT), telomerase RNA (TR) and additional proteins. TERT and TR are required for the telomerase activity in vitro. Telomerase is active in vast majority of the cancer cells ensuring continuous cell division and tumor growth. Syndromes leading to premature aging are often associated with short telomeres. Finding ways to regulate the telomerase activity would help to advance therapies for these conditions. However, the structural information available of the telomerase complex is very limited. We have chosen thermophilic yeast Hansenula polymorpha as a model system due to the stability of its proteins. The N-terminal domain of the TERT is essential for telomerase activity and possibly is involved in binding of TR, telomeric DNA and additional protein components of the telomerase complex. We have crystallised the N-terminal domain of H. polymorpha TERT and, in lack of a homologious structure, produced a seleno-methionine derivative of the protein. MAD data on N-terminal domain has been collected to resolution of 2.0 Å at the PETRA-III beamline P13 (EMBL/DESY) in Hamburg. We will discuss the structure-function relationship of the N-domain and the whole TERT component.