Orientation-aware plasma cell-free DNA fragmentation analysis in open chromatin regions informs tissue of origin.

Cell-free DNA (cfDNA) in human plasma is a class of biomarkers with many current and potential future diagnostic applications. Recent studies have shown that cfDNA molecules are not randomly fragmented and possess information related to their tissues of origin. Pathologies causing death of cells from particular tissues result in perturbations in the relative distribution of DNA from the affected tissues. Such tissue-of-origin analysis is particularly useful in the development of liquid biopsies for cancer. It is therefore of value to accurately determine the relative contributions of the tissues to the plasma DNA pool in a simultaneous manner. In this work, we report that in open chromatin regions, cfDNA molecules show characteristic fragmentation patterns reflected by sequencing coverage imbalance and differentially phased fragment end signals. The latter refers to differences in the read densities of sequences corresponding to the orientation of the upstream and downstream ends of cfDNA molecules in relation to the reference genome. Such cfDNA fragmentation patterns preferentially occur in tissue-specific open chromatin regions where the corresponding tissues contributed DNA into the plasma. Quantitative analyses of such signals allow measurement of the relative contributions of various tissues toward the plasma DNA pool. These findings were validated by plasma DNA sequencing data obtained from pregnant women, organ transplantation recipients, and cancer patients. Orientation-aware plasma DNA fragmentation analysis therefore has potential diagnostic applications in noninvasive prenatal testing, organ transplantation monitoring, and cancer liquid biopsy.

Chinese normotensive and essential hypertensive reference intervals for plasma aldosterone and renin activity by liquid chromatography-tandem mass spectrometry.

OBJECTIVES: The renin-angiotensin-aldosterone system (RAAS) regulates blood pressure. Plasma renin activities (PRA) and plasma aldosterone concentrations (PAC) are biomarkers related to RAAS. Liquid chromatography-tandem mass spectrometry (LC-MS/MS)-based measurements for PRA and PAC have become popular. Method-specific reference intervals (RIs) are required. METHODS: Routine PRA and PAC services in a Hong Kong teaching hospital were based on LC-MS/MS methods. PRA and PAC RIs were developed for normotensive subjects and essential hypertensive (EH) patients. Healthy volunteers were recruited to establish normotensive RIs. PRA and PAC results of hypertensive patients with urine aldosterone tests for primary aldosteronism (PA) screening were retrieved from the laboratory information system. Patients without PA were included. Patients with secondary hypertension and patients on medications affecting the RAAS were excluded. The central 95% RIs were established based on the recommendations of the Clinical and Laboratory Standards Institute guideline C28-A3. RESULTS: PRA and PAC of 170 normotensive volunteers and 362 EH patients were analysed. There was no sex-specific difference in PRA and PAC for normotensive and EH reference subjects. Differences for PRA and PAC were noted between normotensive subjects aged below 45 and their older counterparts. However, such a difference was only identified for PRA but not PAC in EH patients. Age-specific RIs were established accordingly. CONCLUSIONS: This study presented age-specific LC-MS/MS RIs of PRA and PAC for both normotensive and EH populations for local Chinese in Hong Kong.

Biological augmentation of meniscal repair: a systematic review.

PURPOSE: Orthopedic literature remains divided on the utility of biologic augmentation to optimize outcomes after isolated meniscal repair. The aim of this systematic review is to analyze the clinical outcomes and re-operation rates of biologically augmented meniscal repairs. METHODS: PubMed, CINAHL, Cochrane, and EMBASE databases were queried in October 2020 for published literature on isolated meniscal repair with biological augmentation. Studies were assessed for quality and risk of bias by two appraisal tools. Patient demographics, meniscal tear characteristics, surgical procedure, augmentation type, post-operative rehabilitation, patient reported outcome measures, and length of follow-up were recorded, reviewed, and analyzed by two independent reviewers. RESULTS: Of 3794 articles, 18 met inclusion criteria and yielded 537 patients who underwent biologic augmentation of meniscal repair. The biologically augmented repair rates were 5.8-27.0% with PRP augmentation, 0.0-28.5% with fibrin clot augmentation, 0.0-12.9% with marrow stimulation, and 0.0% with stem cell augmentation. One of seven studies showed lower revision rates with augmented meniscal repair compared to standard repair techniques, whereas five of seven found no benefit. Three of ten studies found significant functional improvement of biologically augmented repair versus standard repair techniques and six of ten studies found no difference. There was significant heterogeneity in methods for biologic preparation, delivery, and post-operative rehabilitation protocols. CONCLUSION: Patients reported significant improvements in functional outcomes scores after repair with biological augmentation, though the benefit over standard repair controls is questionable. Revision rates after biologically augmented meniscal repair also appear similar to standard repair techniques. Clinicians should bear this in mind when considering biologic augmentation in the setting of meniscal repair. LEVEL OF EVIDENCE: IV.

Mendelian randomization analyses suggest a role for cholesterol in the development of endometrial cancer.

Blood lipids have been associated with the development of a range of cancers, including breast, lung and colorectal cancer. For endometrial cancer, observational studies have reported inconsistent associations between blood lipids and cancer risk. To reduce biases from unmeasured confounding, we performed a bidirectional, two-sample Mendelian randomization analysis to investigate the relationship between levels of three blood lipids (low-density lipoprotein [LDL] and high-density lipoprotein [HDL] cholesterol, and triglycerides) and endometrial cancer risk. Genetic variants associated with each of these blood lipid levels (P < 5 × 10-8 ) were identified as instrumental variables, and assessed using genome-wide association study data from the Endometrial Cancer Association Consortium (12 906 cases and 108 979 controls) and the Global Lipids Genetic Consortium (n = 188 578). Mendelian randomization analyses found genetically raised LDL cholesterol levels to be associated with lower risks of endometrial cancer of all histologies combined, and of endometrioid and non-endometrioid subtypes. Conversely, higher genetically predicted HDL cholesterol levels were associated with increased risk of non-endometrioid endometrial cancer. After accounting for the potential confounding role of obesity (as measured by genetic variants associated with body mass index), the association between genetically predicted increased LDL cholesterol levels and lower endometrial cancer risk remained significant, especially for non-endometrioid endometrial cancer. There was no evidence to support a role for triglycerides in endometrial cancer development. Our study supports a role for LDL and HDL cholesterol in the development of non-endometrioid endometrial cancer. Further studies are required to understand the mechanisms underlying these findings.

Jagged Ends of Urinary Cell-Free DNA: Characterization and Feasibility Assessment in Bladder Cancer Detection.

BACKGROUND: Double-stranded DNA in plasma is known to carry single-stranded ends, called jagged ends. Plasma DNA jagged ends are biomarkers for pathophysiologic states such as pregnancy and cancer. It remains unknown whether urinary cell-free DNA (cfDNA) molecules have jagged ends. METHODS: Jagged ends of cfDNA were detected by incorporating unmethylated cytosines during a DNA end-repair process, followed by bisulfite sequencing. Incorporation of unmethylated cytosines during the repair of the jagged ends lowered the apparent methylation levels measured by bisulfite sequencing and were used to calculate a jagged end index. This approach is called jagged end analysis by sequencing. RESULTS: The jagged end index of urinary cfDNA was higher than that of plasma DNA. The jagged end index profile of plasma DNA displayed several strongly oscillating major peaks at intervals of approximately 165 bp (i.e., nucleosome size) and weakly oscillating minor peaks with periodicities of approximately 10 bp. In contrast, the urinary DNA jagged end index profile showed weakly oscillating major peaks but strongly oscillating minor peaks. The jagged end index was generally higher in nucleosomal linker DNA regions. Patients with bladder cancer (n = 46) had lower jagged end indexed of urinary DNA than participants without bladder cancer (n = 39). The area under the curve for differentiating between patients with and without bladder cancer was 0.83. CONCLUSIONS: Jagged ends represent a property of urinary cfDNA. The generation of jagged ends might be related to nucleosomal structures, with enrichment in linker DNA regions. Jagged ends of urinary DNA could potentially serve as a new biomarker for bladder cancer detection.

Preferred end coordinates and somatic variants as signatures of circulating tumor DNA associated with hepatocellular carcinoma.

Circulating tumor-derived cell-free DNA (ctDNA) analysis offers an attractive noninvasive means for detection and monitoring of cancers. Evidence for the presence of cancer is dependent on the ability to detect features in the peripheral circulation that are deemed as cancer-associated. We explored approaches to improve the chance of detecting the presence of cancer based on sequence information present on ctDNA molecules. We developed an approach to detect the total pool of somatic mutations. We then investigated if there existed a class of ctDNA signature in the form of preferred plasma DNA end coordinates. Cell-free DNA fragmentation is a nonrandom process. Using plasma samples obtained from liver transplant recipients, we showed that liver contributed cell-free DNA molecules ended more frequently at certain genomic coordinates than the nonliver-derived molecules. The abundance of plasma DNA molecules with these liver-associated ends correlated with the liver DNA fractions in the plasma samples. Studying the DNA end characteristics in plasma of patients with hepatocellular carcinoma and chronic hepatitis B, we showed that there were millions of tumor-associated plasma DNA end coordinates in the genome. Abundance of plasma DNA molecules with tumor-associated DNA ends correlated with the tumor DNA fractions even in plasma samples of hepatocellular carcinoma patients that were subjected to shallow-depth sequencing analysis. Plasma DNA end coordinates may therefore serve as hallmarks of ctDNA that could be sampled readily and, hence, may improve the cost-effectiveness of liquid biopsy assessment.

Glenoid Pathology, Skeletal Immaturity, and Multiple Preoperative Instability Events Are Risk Factors for Recurrent Anterior Shoulder Instability After Arthroscopic Stabilization in Adolescent Athletes.

PURPOSE: To identify risk factors for recurrent shoulder instability after arthroscopic stabilization in adolescent athletes. METHODS: A retrospective case-control study was undertaken of all patients younger than 18 years undergoing arthroscopic shoulder stabilization for anterior instability between 2009 and 2016. Two patient cohorts were identified: (1) patients with recurrent instability (frank dislocations or subluxations) after arthroscopic stabilization and (2) an age- and sex-matched cohort of patients with no recurrent instability at a minimum of 2 years' follow-up from index surgery. Patient demographic, injury, radiographic, and surgical variables were recorded. Variables with P < .10 on univariate analysis were entered into a binary logistic multivariate regression analysis. RESULTS: We identified 35 patients (20.5%) in whom arthroscopic stabilization failed at a mean of 1.2 ± 1.0 years after their index surgical procedure. A separate age- and sex-matched cohort of 35 patients with no evidence of recurrent instability was identified (mean follow-up, 5.4 ± 2.0 years; minimum follow-up, 2 years). Univariate analysis identified increased glenoid bone loss (P = .039), decreased glenoid retroversion (P = .024), and more than 1 instability event prior to surgery (P = .017) as significant risk factors for recurrent instability. Multivariate regression analysis revealed that glenoid retroversion less than 6°, skeletal immaturity, and more than 1 prior instability event significantly and independently predicted future recurrence. The risk of recurrence after arthroscopic stabilization was increased by 3 times in patients with 2 risk factors and by 4 times in patients with all 3 risk factors. CONCLUSIONS: Anterior glenoid bone loss, glenoid version, skeletal immaturity, and multiple preoperative instability events are risk factors for failed arthroscopic stabilization in adolescent athletes with anterior instability. LEVEL OF EVIDENCE: Level III, case-control study.

Anticoagulation and antiplatelet therapy post coronary artery bypass surgery.

BACKGROUND: Coronary artery bypass grafting (CABG) is the gold standard treatment for patients with multivessel coronary heart disease. Although its use has proven long-term survival benefits, there is a relative degree of graft failure which increases morbidity and mortality rates. DISCUSSION: This review discusses clinical outcomes following antiplatelet and anticoagulant therapy after CABG. There is wide variation of evidence about the use of clopidogrel or ticagrelor to aspirin postoperatively in relation to improving graft patency rates or clinical outcomes over the use of aspirin alone. These dual therapies may have significant protective effects in patients undergoing off-pump CABG. Recent studies suggest that superior outcomes may be attained by combining prasugrel with aspirin. Further research is needed to evaluate this, as well as compare the effectiveness of different dual antiplatelet regimens. There is weak evidence for post-CABG anticoagulation, with warfarin and rivaroxaban providing no protection against graft failure but decreasing long-term major adverse cardiac events. Anticoagulation seems to be indicated only in post-CABG patients at high risk of future ischemic events. CONCLUSION: The use of dual anti-platelet therapy post coronary artery bypass surgery needs further research. Potentially, selective patient groups will benefit more from the addition of thienopyridine antiplatelets or anticoagulants to aspirin after CABG.

Rehabilitation variability after rotator cuff repair.

BACKGROUND: There has been increasing recognition of the importance for standardized postoperative rehabilitation protocols. Despite published guidelines in 2016 by the American Society of Shoulder and Elbow Therapists (ASSET), optimal postoperative rehabilitation after rotator cuff repair (RCR) remains an area of active academic debate. The goals of this study were (1) to assess the variability of RCR rehabilitation protocols published online, (2) to study the congruence between online RCR rehabilitation protocols and the ASSET consensus statement, and (3) to identify differences in online RCR rehabilitation protocols from before and after 2016. METHODS: A web-based search was conducted for publicly available RCR rehabilitation protocols from websites of all Accreditation Council for Graduate Medical Education (ACGME) academic orthopedic institutions. A supplemental 10-page Google search was also performed with the search terms "rotator cuff repair rehabilitation protocol." Collected protocols were grouped by tear size (small/medium or large/massive) and examined for information relating to the following categories: protocol demographics, adjunctive therapy use, immobilization/range of motion, and strengthening. Findings were compared to the ASSET statement's recommendations. Protocols published before and after ASSET's 2016 publication were compared for differences. RESULTS: A total of 66 online RCR rehabilitation protocols were collected. Only 16 of 187 (8.5%) ACGME institutions provided online RCR rehabilitation protocols. The collected protocols recommend more aggressive rehabilitation in comparison to ASSET, specifically regarding immobilization time, passive range of motion initiation, active assisted range of motion initiation, and strengthening initiation (P < .001). Protocols published after 2016 trended toward more conservative recommendations in comparison to protocols published before 2016. Regardless of this trend, the majority of these recommendations were still largely more aggressive than ASSET's recommendations. CONCLUSION: Despite an attempt by ASSET to provide standardization, this study highlights the marked variations that still exist regarding RCR rehabilitation. Additionally, online RCR rehabilitation protocols tend to make more aggressive recommendations than the ASSET consensus statement. Further research is needed to address these variations and to either validate, alter, or reject the ASSET recommendations.

Comprehensive characterization and resolution of discrepant spectrophotometric bilirubin results in patients on eltrombopag therapy.

Background Eltrombopag is a thrombopoietin receptor agonist used for the treatment of thrombocytopenic conditions. It can cause pH-dependent discoloration of plasma/serum. Eltrombopag is potentially hepatotoxic. It can affect the assessment of hyperbilirubinemia because of its (i) absorbance at ~450 nm (bilirubin), (ii) absorbance at ~550 nm (diazo-bilirubin) and (iii) it can cause yellowish discoloration of the eyes at normal circulating bilirubin levels. Methods We collected 66 samples from patients on a range of eltrombopag dosages up to 150 mg daily. Bilirubin was measured using multiple routine spectrophotometric analyzers, the Doumas reference method and high-performance liquid chromatography (HPLC). Plasma/serum eltrombopag concentrations were determined using liquid chromatography tandem mass spectrometry (LC-MS/MS). Spike-in and admixture experiments delineated the effects of eltrombopag and its metabolites. Results Forty-nine of 52 samples from patients on ≥50 mg daily eltrombopag therapy showed significantly discrepant inter-analyzer total bilirubin results, a difference up to 64 µmol/L (3.7 mg/dL). In one sample, total bilirubin varied from 8 to 65 µmol/L (0.4-3.8 mg/dL) by different routine analyzers, with direct bilirubin ≤4 µmol/L (0.2 mg/dL). There was a positive correlation between total bilirubin difference and plasma eltrombopag concentration (r = 0.679), and spike-in experiments demonstrated that Beckman AU and Doumas reference methods were susceptible to positive interference. HPLC can quantify bilirubin after separating eltrombopag, and results suggest different analyzers are affected to varying degrees by eltrombopag and its metabolites. Conclusions Eltrombopag and its metabolites can cause positive interference to the spectrophotometric measurements of total bilirubin. Accurate measurements of total bilirubin may improve our understanding of the prevalence of hyperbilirubinemia in patients on eltrombopag therapy.

Paget-Schroetter syndrome in athletes: a comprehensive and systematic review.

BACKGROUND: Paget-Schroetter syndrome (PSS) is a rare condition of axillosubclavian vein thrombosis often seen in athletes with a history of repetitive external rotation and abduction of the shoulder. The purpose of this review was to analyze the literature and characterize PSS in the athletic population, including risk of PSS by sport. We also provide a comprehensive review of PSS to inform clinicians on the pathophysiology, detection, and management of the condition. METHODS: Four databases were reviewed to identify cases of PSS occurring in athletes. Data on patient demographics, reported sport, diagnosis, treatment, management, return to sport, and complications were extracted and analyzed by 2 independent reviewers. RESULTS: Of the 123 cases of PSS identified, baseball and weight lifting had the highest incidence (26.8% and 19%, respectively), followed by swimming, football, and basketball. The average return to sport was 4.7 months, and 26.7% of subjects reported complications, most commonly pulmonary embolism. CONCLUSION: In athletes presenting with upper extremity pain and swelling with a history of playing baseball or weight lifting, PSS should be higher on a clinicians differential diagnosis list. Swimmers, football, and basketball players are less likely to present with PSS but are still more likely than other types of athletes to develop the condition. Clinician awareness of PSS in athletes is critical to avoid delays in treatment and misdiagnosis, and to allow for a timely return to sport with minimal complications.

A Common Variant at the 14q32 Endometrial Cancer Risk Locus Activates AKT1 through YY1 Binding.

A recent meta-analysis of multiple genome-wide association and follow-up endometrial cancer case-control datasets identified a novel genetic risk locus for this disease at chromosome 14q32.33. To prioritize the functional SNP(s) and target gene(s) at this locus, we employed an in silico fine-mapping approach using genotyped and imputed SNP data for 6,608 endometrial cancer cases and 37,925 controls of European ancestry. Association and functional analyses provide evidence that the best candidate causal SNP is rs2494737. Multiple experimental analyses show that SNP rs2494737 maps to a silencer element located within AKT1, a member of the PI3K/AKT/MTOR intracellular signaling pathway activated in endometrial tumors. The rs2494737 risk A allele creates a YY1 transcription factor-binding site and abrogates the silencer activity in luciferase assays, an effect mimicked by transfection of YY1 siRNA. Our findings suggest YY1 is a positive regulator of AKT1, mediating the stimulatory effects of rs2494737 increasing endometrial cancer risk. Identification of an endometrial cancer risk allele within a member of the PI3K/AKT signaling pathway, more commonly activated in tumors by somatic alterations, raises the possibility that well tolerated inhibitors targeting this pathway could be candidates for evaluation as chemopreventive agents in individuals at high risk of developing endometrial cancer.

Noninvasive Detection of Bladder Cancer by Shallow-Depth Genome-Wide Bisulfite Sequencing of Urinary Cell-Free DNA for Methylation and Copy Number Profiling.

BACKGROUND: The current diagnosis and monitoring of bladder cancer are heavily reliant on cystoscopy, an invasive and costly procedure. Previous efforts in urine-based detection of bladder cancer focused on targeted approaches that are predicated on the tumor expressing specific aberrations. We aimed to noninvasively detect bladder cancer by the genome-wide assessment of methylomic and copy number aberrations (CNAs). We also investigated the size of tumor cell-free (cf)DNA fragments. METHODS: Shallow-depth paired-end genome-wide bisulfite sequencing of urinary cfDNA was done for 46 bladder cancer patients and 39 cancer-free controls with hematuria. We assessed (a) proportional contribution from different tissues by methylation deconvolution, (b) global hypomethylation, (c) CNA, and (d) cfDNA size profile. RESULTS: Methylomic and copy number approaches were synergistically combined to detect bladder cancer with a sensitivity of 93.5% (84.2% for low-grade nonmuscle-invasive disease) and a specificity of 95.8%. The prevalence of methylomic and CNAs reflected disease stage and tumor size. Sampling over multiple time points could assess residual disease and changes in tumor load. Muscle-invasive bladder cancer was associated with a higher proportion of long cfDNA, as well as longer cfDNA fragments originating from genomic regions enriched for tumor DNA. CONCLUSIONS: Bladder cancer can be detected noninvasively in urinary cfDNA by methylomic and copy number analysis without previous knowledge or assumptions of specific aberrations. Such analysis could be used as a liquid biopsy to aid diagnosis and for potential longitudinal monitoring of tumor load. Further understanding of the differential size and fragmentation of cfDNA could improve the detection of bladder cancer.

GWAS meta-analysis of 16 852 women identifies new susceptibility locus for endometrial cancer.

Endometrial cancer is the most common gynecological malignancy in the developed world. Although there is evidence of genetic predisposition to the disease, most of the genetic risk remains unexplained. We present the meta-analysis results of four genome-wide association studies (4907 cases and 11 945 controls total) in women of European ancestry. We describe one new locus reaching genome-wide significance (P < 5 × 10 -8) at 6p22.3 (rs1740828; P = 2.29 × 10 -8, OR = 1.20), providing evidence of an additional region of interest for genetic susceptibility to endometrial cancer.

Identification and characterization of novel associations in the CASP8/ALS2CR12 region on chromosome 2 with breast cancer risk.

Previous studies have suggested that polymorphisms in CASP8 on chromosome 2 are associated with breast cancer risk. To clarify the role of CASP8 in breast cancer susceptibility, we carried out dense genotyping of this region in the Breast Cancer Association Consortium (BCAC). Single-nucleotide polymorphisms (SNPs) spanning a 1 Mb region around CASP8 were genotyped in 46 450 breast cancer cases and 42 600 controls of European origin from 41 studies participating in the BCAC as part of a custom genotyping array experiment (iCOGS). Missing genotypes and SNPs were imputed and, after quality exclusions, 501 typed and 1232 imputed SNPs were included in logistic regression models adjusting for study and ancestry principal components. The SNPs retained in the final model were investigated further in data from nine genome-wide association studies (GWAS) comprising in total 10 052 case and 12 575 control subjects. The most significant association signal observed in European subjects was for the imputed intronic SNP rs1830298 in ALS2CR12 (telomeric to CASP8), with per allele odds ratio and 95% confidence interval [OR (95% confidence interval, CI)] for the minor allele of 1.05 (1.03-1.07), P = 1 × 10(-5). Three additional independent signals from intronic SNPs were identified, in CASP8 (rs36043647), ALS2CR11 (rs59278883) and CFLAR (rs7558475). The association with rs1830298 was replicated in the imputed results from the combined GWAS (P = 3 × 10(-6)), yielding a combined OR (95% CI) of 1.06 (1.04-1.08), P = 1 × 10(-9). Analyses of gene expression associations in peripheral blood and normal breast tissue indicate that CASP8 might be the target gene, suggesting a mechanism involving apoptosis.

Fine-mapping of the HNF1B multicancer locus identifies candidate variants that mediate endometrial cancer risk.

Common variants in the hepatocyte nuclear factor 1 homeobox B (HNF1B) gene are associated with the risk of Type II diabetes and multiple cancers. Evidence to date indicates that cancer risk may be mediated via genetic or epigenetic effects on HNF1B gene expression. We previously found single-nucleotide polymorphisms (SNPs) at the HNF1B locus to be associated with endometrial cancer, and now report extensive fine-mapping and in silico and laboratory analyses of this locus. Analysis of 1184 genotyped and imputed SNPs in 6608 Caucasian cases and 37 925 controls, and 895 Asian cases and 1968 controls, revealed the best signal of association for SNP rs11263763 (P = 8.4 × 10(-14), odds ratio = 0.86, 95% confidence interval = 0.82-0.89), located within HNF1B intron 1. Haplotype analysis and conditional analyses provide no evidence of further independent endometrial cancer risk variants at this locus. SNP rs11263763 genotype was associated with HNF1B mRNA expression but not with HNF1B methylation in endometrial tumor samples from The Cancer Genome Atlas. Genetic analyses prioritized rs11263763 and four other SNPs in high-to-moderate linkage disequilibrium as the most likely causal SNPs. Three of these SNPs map to the extended HNF1B promoter based on chromatin marks extending from the minimal promoter region. Reporter assays demonstrated that this extended region reduces activity in combination with the minimal HNF1B promoter, and that the minor alleles of rs11263763 or rs8064454 are associated with decreased HNF1B promoter activity. Our findings provide evidence for a single signal associated with endometrial cancer risk at the HNF1B locus, and that risk is likely mediated via altered HNF1B gene expression.

Candidate locus analysis of the TERT-CLPTM1L cancer risk region on chromosome 5p15 identifies multiple independent variants associated with endometrial cancer risk.

Several studies have reported associations between multiple cancer types and single-nucleotide polymorphisms (SNPs) on chromosome 5p15, which harbours TERT and CLPTM1L, but no such association has been reported with endometrial cancer. To evaluate the role of genetic variants at the TERT-CLPTM1L region in endometrial cancer risk, we carried out comprehensive fine-mapping analyses of genotyped and imputed SNPs using a custom Illumina iSelect array which includes dense SNP coverage of this region. We examined 396 SNPs (113 genotyped, 283 imputed) in 4,401 endometrial cancer cases and 28,758 controls. Single-SNP and forward/backward logistic regression models suggested evidence for three variants independently associated with endometrial cancer risk (P = 4.9 × 10(-6) to P = 7.7 × 10(-5)). Only one falls into a haplotype previously associated with other cancer types (rs7705526, in TERT intron 1), and this SNP has been shown to alter TERT promoter activity. One of the novel associations (rs13174814) maps to a second region in the TERT promoter and the other (rs62329728) is in the promoter region of CLPTM1L; neither are correlated with previously reported cancer-associated SNPs. Using TCGA RNASeq data, we found significantly increased expression of both TERT and CLPTM1L in endometrial cancer tissue compared with normal tissue (TERT P = 1.5 × 10(-18), CLPTM1L P = 1.5 × 10(-19)). Our study thus reports a novel endometrial cancer risk locus and expands the spectrum of cancer types associated with genetic variation at 5p15, further highlighting the importance of this region for cancer susceptibility.

Much of the genetic risk of colorectal cancer is likely to be mediated through susceptibility to adenomas.

Several single-nucleotide polymorphisms (SNPs) have been associated with colorectal cancer (CRC) susceptibility. Most CRCs arise from adenomas, and SNPs therefore might affect predisposition to CRC by increasing adenoma risk. We found that 8 of 18 known CRC-associated SNPs (rs10936599, rs6983267, rs10795668, rs3802842, rs4444235, rs1957636, rs4939827, and rs961253) were over-represented in CRC-free patients with adenomas, compared with controls. Ten other CRC-associated SNPs (rs6691170, rs6687758, rs16892766, rs7136702, rs11169552, rs4779584, rs9929218, rs10411210, rs4813802, and rs4925386) were not associated significantly with adenoma risk. Genetic susceptibility to CRC in the general population is likely to be mediated in part by predisposition to adenomas.

MHC class I modulates NMDA receptor function and AMPA receptor trafficking.

Proteins of the major histocompatibility complex class I (MHCI) are known for their role in immunity and have recently been implicated in long-term plasticity of excitatory synaptic transmission. However, the mechanisms by which MHCI influences synaptic plasticity remain unknown. Here we show that endogenous MHCI regulates synaptic responses mediated by NMDA-type glutamate receptors (NMDARs) in the mammalian central nervous system (CNS). The AMPA/NMDA ratio is decreased at MHCI-deficient hippocampal synapses, reflecting an increase in NMDAR-mediated currents. This enhanced NMDAR response is not associated with changes in the levels, subunit composition, or gross subcellular distribution of NMDARs. Increased NMDAR-mediated currents in MHCI-deficient neurons are associated with characteristic changes in AMPA receptor trafficking in response to NMDAR activation. Thus, endogenous MHCI tonically inhibits NMDAR function and controls downstream NMDAR-induced AMPA receptor trafficking during the expression of plasticity.