Design of 2-Pyridone Fluorophores for Brighter Emissions at Longer Wavelengths.

The recent discovery of blue fluorophores with high quantum yields based on pyridone structures inspired the development of new low-molecular-weight fluorophores with bright emissions at tunable wavelengths, which are highly attractive for various applications. In this study, we propose a rational design strategy for 2-pyridone-based fluorophores with bright emissions at long wavelengths. With a detailed understanding of the positional substitution effects on each carbon atom of the 2-pyridone core, we developed a bright blue fluorophore (λabs =377 nm; λem =433 nm; ϵ=13,200 M-1 cm-1 ; ϕF =88 %) through C3 -aryl and C4 -ester substitutions followed by cyclization. Furthermore, by applying the intramolecular charge transfer (ICT) principle, we invented a bright green fluorophore through C3 - and C4 -diester and C6 -aryl substitutions. The ICT fluorophore based on the pyridone structure shows large molar absorptivity (ϵ=20,100 M-1 cm-1 ), longer emission wavelength (λem =539 nm), high emission quantum yield (ϕF =74 %), and large Stokes shift (Δv=5720 cm-1 ), which are comparable to those of practical fluorescent probes.

Fatty Liver Change in Older Adults as an Important Risk Factor for Type 2 Diabetes: A Nationwide Cohort Study.

OBJECTIVE: To examine the association between changes in fatty liver disease (FLD) over time and the risk of type 2 diabetes in elderly individuals with prediabetes. METHODS: A total of 156,984 elderly individuals with prediabetes who underwent national health screening in 2009 and 2011 were followed up through December 31, 2019. The FLD status was defined as a change in the fatty liver index. Prediabetes was defined as impaired fasting glucose levels at baseline. Multivariable Cox proportional hazards regression was used to calculate the hazard ratio and CIs for type 2 diabetes according to the changes in FLD. RESULTS: During a median of 8.35 years of follow-up, type 2 diabetes developed in 29,422 (18.7%) elderly individuals with prediabetes. Multivariable adjusted hazard ratio of type 2 diabetes according to FLD change was 2.22 (95% CI, 2.11 to 2.34) in individuals with persistent FLD compared with those who have never had FLD. Although overall weight loss of 5% or more was associated with a 7% lower risk of type 2 diabetes in total participants, fatty liver status was important. Even with weight loss, those with a history of fatty liver-resolved FLD, new FLD, or persistent FLD-had an increased risk of type 2 diabetes. The risk of type 2 diabetes did not increase in individuals with sustained FLD-free status, regardless of weight change. CONCLUSION: The presence and change of FLD are important factors for the development of type 2 diabetes in elderly individuals with prediabetes.

Spectral Efficiency Improvement Using Bi-Deep Learning Model for IRS-Assisted MU-MISO Communication System.

The intelligent reflecting surface (IRS) is a two-dimensional (2D) surface with a programmable structure and is composed of many arrays. The arrays are used to supervise electromagnetic wave propagation by altering the electric and magnetic properties of the 2D surface. IRS can influentially convert wireless channels to very effectively enhance spectral efficiency (SE) and communication performance in wireless systems. However, proper channel information is necessary to realize the IRS anticipated gains. The conventional technique has been taken into consideration in recent attempts to fix this issue, which is straightforward but not ideal. A deep learning model which is called the long short-term memory (Bi-LSTM) model can tackle this issue due to its good learning capability and it plays a vital role in enhancing SE. Bi-LSTM can collect data from both forward and backward directions simultaneously to provide improved prediction accuracy. Because of the tremendous benefits of the Bi-LSTM model, in this paper, an IRS-assisted Bi-LSTM model-based multi-user multiple input single output downlink system is proposed for SE improvement. A Wiener filter is used to determine the optimal phase of each IRS element. In the simulation results, the proposed system is compared with other DL models and methods for the SE performance evaluation. The model exhibits satisfactory SE performance with a different signal-to-noise ratio compared to other schemes in the online phase.

Incidence and risk factors of hypoparathyroidism and hypocalcemia after hemithyroidectomy.

PURPOSE: The incidence and risk factors for hypoparathyroidism after total thyroidectomy is well-known. However, the characteristics of hypoparathyroidism and hypocalcemia after hemithyroidectomy have not been investigated well. In this study, we aimed to evaluate the incidence, characteristics, and risk factors of hypoparathyroidism and hypocalcemia after hemithyroidectomy. METHOD: We retrospectively analyzed the medical data of 321 patients who underwent hemithyroidectomy, with or without central neck dissection, from January 2012 to April 2019. We analyzed the serum intact parathyroid hormone (iPTH), calcium, and ionized calcium (iCa) levels serially (preoperatively and postoperatively on the operation day; days 1 and 3; and months 1, 3, 6, and 12) and evaluated risk factors for postoperative hypoparathyroidism and hypocalcemia. RESULTS: The mean iPTH and calcium levels decreased significantly after hemithyroidectomy on the operation day and postoperative days 1 and 3, and returned to the preoperative level at the postoperative 1-month follow-up. The mean iCa level decreased significantly on the operation day and postoperative day 1. Transient hypoparathyroidism and transient hypocalcemia occurred in 16 (5%) and 250 (78%) participants, and they recovered to normal levels postoperatively by 1 month. Eight (2.5%) patients had mild symptoms of hypocalcemia necessitating oral calcium supplementation. No permanent hypoparathyroidism or hypocalcemia was observed. Preoperatively low serum iPTH and calcium levels were associated with transient hypoparathyroidism and hypocalcemia after hemithyroidectomy. CONCLUSION: Approximately 5% and 2.5% of participants showed transient hypoparathyroidism and mild symptomatic hypocalcemia after hemithyroidectomy. The risk factors for transient hypoparathyroidism and hypocalcemia include preoperative low serum iPTH and calcium levels.

Higher Non-High-Density Lipoprotein Cholesterol Was Higher Associated With Cardiovascular Disease Comparing Higher LDL-C in Nine Years Follow Up: Cohort Study.

Objective: Non-high-density lipoprotein cholesterol (non-HDL-C) may be equivalent to or superior to low-density lipoprotein cholesterol (LDL-C) for the prediction of cardiovascular disease (CVD). However, studies comparing the predictive values of LDL-C and non-HDL-C levels for CVD have yielded conflicting results. In this study, we evaluated the relationship between non-HDL-C, LDL-C, and CVD using a large-scale population dataset from the National Health Information Database (NHID). Methods: We performed a retrospective observational cohort study of 3,866,366 individuals ≥ 20 years, from 2009 to 2018, using the NHID. The participants were divided into LDL-C and non-HDL-C quartiles. The outcome variables included stroke, myocardial infarction (MI), and both. All outcomes were analyzed using Cox proportional hazards regression analysis while controlling for baseline covariates (age, sex, smoking, drinking, regular exercise, body mass index, diabetes, hypertension, and statin use). Results: During 9.1 years of mean follow-up, stroke was diagnosed in 60,081 (1.55%), MI in 31,234 (0.81%), and both stroke and MI in 88,513 (2.29%) participants. Multivariate-adjusted hazard ratios (HRs) for patients in the highest non-HDL-C quartile demonstrated that these patients had a higher risk of stroke (HR, 1.254; 95% confidence interval [CI], 1.224-1.285), MI (HR, 1.918; 95% CI, 1.853-1.986), and both (HR, 1.456; 95% CI, 1.427-1.486) compared with participants in the lowest quartile. These were higher than the HRs for patients in the highest LDL-C quartile for stroke (HR, 1.134; 95% CI, 1.108-1.160), MI (HR, 1.601; 95% CI, 1.551-1.653), and both (HR, 1.281; 95% CI, 1.257-1.306). Conclusion: In our large population study, higher non-HDL-C levels were associated with CVD than LDL-C levels.

NAA10 Hypomethylation is associated with particulate matter exposure and worse prognosis for patients with non-small cell lung cancer.

Airborne particulate matter (PM) is a major health hazard worldwide and is a key factor in lung cancer, which remains the most common type of malignancy and the leading cause of cancer-related deaths. DNA methylation is a critical mechanism underlying the detrimental effects of PM, however, the molecular link between PM exposure and lung cancer remains to be elucidated. N-α-acetyltransferase 10 (NAA10) is involved in the cell cycle, migration, apoptosis, differentiation, and proliferation. In order to investigate the role of NAA10 in PM-induced pathogenesis processes leading to lung cancer, we determined the expression and methylation of NAA10 in normal human bronchial epithelial (NHBE) cells treated with PM10, PM10-polycyclic aromatic hydrocarbons (PAH), and PM2.5 and evaluated the prognostic value of the NAA10 methylation status in lung cancer patients. Exposure to all PM types significantly increased the expression of NAA10 mRNA and decreased the methylation of the NAA10 promoter in NHBE cells compared with the mock-treated control. NAA10 hypomethylation was observed in 9.3% (13/140) of lung cancer tissue samples and correlated with NAA10 transcriptional upregulation. Univariate and multivariate analyses revealed that NAA10 hypomethylation was associated with decreased survival of patients with lung cancer. Therefore, these results suggest that PM-induced hypomethylation of the NAA10 may play an important role in the pathogenesis of lung cancer and may be used as a potential prognostic biomarker for lung cancer progression. Further studies with large numbers of patients are warranted to confirm our findings.

Epigenetic and genetic inactivation of tumor suppressor miR-135a in non-small-cell lung cancer.

BACKGROUND: Despite therapeutic advances, lung cancer prognosis remains poor. Loss of heterozygosity (LOH) in the 3p21 region is well documented in lung cancer, but the specific causative genes have not been identified. MATERIALS AND METHODS: Here, we aimed to examine the clinical impact of miR-135a, located in the 3p21 region, in lung cancer. miR-135a expression was assessed using quantitative real-time polymerase chain reaction. LOH was analyzed at microsatellite loci D3S1076 and D3S1478, and promoter methylation status was determined by pyrosequencing of resected samples of primary non-small-cell lung cancer (NSCLC). The regulation of telomerase reverse transcriptase (TERT) was evaluated in lung cancer cells H1299 by luciferase report assays after treatment with miR-135a mimics. RESULTS: miR-135a was significantly downregulated in squamous cell cancer (SCC) tumor tissues compared to normal tissues (p = 0.001). Low miR-135a expression was more frequent in patients with SCC (p = 2.9 × 10-4 ) and smokers (p = 0.01). LOH and hypermethylation were detected in 27.8% (37/133) and 17.3% (23/133) of the tumors, respectively. Overall, 36.8% (49/133) of the NSCLC cases harbored either miR-135a LOH or promoter hypermethylation. The frequencies of LOH and hypermethylation were significantly associated with SCCs (p = 2 × 10-4 ) and late-stage (p = 0.04), respectively. MiR-135a inhibited the relative luciferase activity of psiCHECK2-TERT-3'UTR. CONCLUSION: These results suggest that miR-135a may act as a tumor suppressor to play an important role in lung cancer carcinogenesis, which will provide a new insight into the translational value of miR-135a. Further large-scale studies are required to confirm these findings.

Five-Year Oncologic Outcome and Surgical Completeness of Transoral Robotic Thyroidectomy for Papillary Thyroid Carcinoma: Comparison with Conventional Transcervical Thyroidectomy Using Propensity Score Matching.

OBJECTIVE: This study aimed to evaluate the oncological outcomes and surgical completeness of transoral robotic thyroidectomy (TORT) for papillary thyroid carcinoma (PTC) compared with conventional transcervical thyroidectomy. METHODS: We analyzed 489 patients with PTC who underwent thyroidectomy with or without central neck dissection (CND; 311 conventional thyroidectomy and 178 TORT) between January 2017 and December 2021. Patients with gross invasion of the surrounding structures, revision or completion thyroidectomy, and lateral neck dissection were excluded. Propensity score-matched analysis was performed using eight covariates, including age, sex, extent of thyroidectomy, tumor size, extrathyroidal extension (ETE), radioactive iodine (RAI) ablation, lymphovascular invasion (LVI), and CND. RESULTS: Before propensity score matching (PSM), age, male-to-female ratio, and body mass index were lower in the TORT group. The ratio of total thyroidectomy and CND, tumor size and bilaterality, LVI, and RAI ablation were higher in the conventional group. PSM generated two matched groups of 100 patients each. After PSM, significant differences between the two groups in the baseline analysis disappeared. In the matched samples, the recurrence rate (2% and 0% in the conventional and TORT groups, respectively) and recurrence-free survival curves did not differ between the two groups. The mean thyroid-stimulating hormone (TSH)-stimulated thyroglobulin level in the RAI group and TSH-suppressed thyroglobulin level in the non-RAI group were not different between the two groups. CONCLUSIONS: The 5-year oncologic outcomes and surgical completeness of TORT were comparable with those of conventional thyroidectomy in patients with small, localized, low-risk PTC when performed by experienced surgeons.

A Comprehensive Survey on MIMO Visible Light Communication: Current Research, Machine Learning and Future Trends.

Visible light communication (VLC) has contributed new unused spectrum in addition to the traditional radio frequency communication and can play a significant role in wireless communication. The adaptation of VLC technology enhances wireless connectivity both in indoor and outdoor environments. Multiple-input multiple-output (MIMO) communication has been an efficient technique for increasing wireless communications system capacity and performance. With the advantages of MIMO techniques, VLC can achieve an additional degree of freedom. In this paper, we systematically perform a survey of the existing work based on MIMO VLC. We categorize the types of different MIMO techniques, and a brief description is given. Different problem-solving approaches are given in the subsequent sections. In addition, machine learning approaches are also discussed in sufficient detail. Finally, we identify the future study direction for MIMO-based communication in VLC.

Feasibility of transoral robotic selective neck dissection with or without a postauricular incision for papillary thyroid carcinoma: A pilot study.

Background: The study aimed to evaluate the feasibility of transoral robotic selective neck dissection (SND) with or without a postauricular incision for papillary thyroid carcinoma (PTC). Methods: We studied 14 patients with PTC who underwent robotic SND via the transoral or combined transoral and postauricular approaches. Results: The transoral approach was performed on 10 patients for dissection of levels III and IV. An additional postauricular incision was made on 4 patients for dissection of level II in addition to levels III, IV, and V. The operation was completed successfully in 13 patients, except 1 patient with the procedure conversion due to uncontrolled bleeding from the internal jugular vein. The mean numbers of removed lymph nodes in the lateral compartment were 23.1 ± 9.4 and 38.3 ± 8.5 in the transoral and combined groups. Transient recurrent laryngeal nerve palsy occurred in 1 patient, transient hypoparathyroidism in 3 patients, and chyle leakage in 1 patient. There were no hematomas, mental nerve injuries, surgical space infections, or CO2 embolisms. Conclusion: Transoral robotic SND is feasible with or without a postauricular incision.

Three-dimensional visualization of cerebral blood vessels and neural changes in thick ischemic rat brain slices using tissue clearing.

Blood vessels are three-dimensional (3D) in structure and precisely connected. Conventional histological methods are unsuitable for their analysis because of the destruction of functionally important topological 3D vascular structures. Tissue optical clearing techniques enable extensive volume imaging and data analysis without destroying tissue. This study therefore applied a tissue clearing technique to acquire high-resolution 3D images of rat brain vasculature using light-sheet and confocal microscopies. Rats underwent middle cerebral artery occlusion for 45 min followed by 24 h reperfusion with lectin injected directly into the heart for vascular staining. For acquiring 3D images of rat brain vasculature, 3-mm-thick brain slices were reconstructed using tissue clearing and light-sheet microscopy. Subsequently, after 3D rendering, the fitting of blood vessels to a filament model was used for analysis. The results revealed a significant reduction in vessel diameter and density in the ischemic region compared to those in contralesional non-ischemic regions. Immunostaining of 0.5-mm-thick brain slices revealed considerable neuronal loss and increased astrocyte fluorescence intensity in the ipsilateral region. Thus, these methods can provide more accurate data by broadening the scope of the analyzed regions of interest for examining the 3D cerebrovascular system and neuronal changes occurring in various brain disorders.

Asymmetric Contribution of Blastomere Lineages of First Division of the Zygote to Entire Human Body Using Post-Zygotic Variants.

BACKGROUND: In humans, after fertilization, the zygote divides into two 2n diploid daughter blastomeres. During this division, DNA is replicated, and the remaining mutually exclusive genetic mutations in the genome of each cell are called post-zygotic variants. Using these somatic mutations, developmental lineages can be reconstructed. How these two blastomeres are contributing to the entire body is not yet identified. This study aims to evaluate the cellular contribution of two blastomeres of 2-cell embryos to the entire body in humans using post-zygotic variants based on whole genome sequencing. METHODS: Tissues from different anatomical areas were obtained from five donated cadavers for use in single-cell clonal expansion and bulk target sequencing. After conducting whole genome sequencing, computational analysis was applied to find the early embryonic mutations of each clone. We developed our in-house bioinformatics pipeline, and filtered variants using strict criteria, composed of mapping quality, base quality scores, depth, soft-clipped reads, and manual inspection, resulting in the construction of embryological phylogenetic cellular trees. RESULTS: Using our in-house pipeline for variant filtering, we could extract accurate true positive variants, and construct the embryological phylogenetic trees for each cadaver. We found that two daughter blastomeres, L1 and L2 (lineage 1 and 2, respectively), derived from the zygote, distribute unequally to the whole body at the clonal level. From bulk target sequencing data, we validated asymmetric contribution by means of the variant allele frequency of L1 and L2. The asymmetric contribution of L1 and L2 varied from person to person. CONCLUSION: We confirmed that there is asymmetric contribution of two daughter blastomeres from the first division of the zygote across the whole human body.

Particulate matter-induced hypomethylation of Alu and LINE1 in normal human bronchial epithelial cells and epidermal keratinocytes.

BACKGROUND: Airborne particulate matter (PM), a complex mixture of organic and inorganic compounds, is a major public health concern due to its adverse health effects. Understanding the biological action of PM is of particular importance in the improvement of public health. Differential methylation of repetitive elements (RE) by PM might have severe consequences for the structural integrity of the genome and on transcriptional activity, thereby affecting human health. This study aimed to evaluate the effect of inhaled and non-inhaled PM (PM2.5, PM10, and PM10-PAH) exposure on DNA methylation. We quantitatively measured the methylation content of Alu and LINE1 in PM-treated normal human bronchial epithelial cells (NHBE) and normal human epidermal keratinocytes (NHEK) by using whole-genome bisulfite sequencing and pyrosequencing. RESULTS: All PMs exposure significantly lowered Alu and LINE1 methylation in both cells than in mock-treated controls. Hypomethylation was more prominent in PM10-PAH exposed-NHBE and PM10 exposed-NHEK. Alu and LINE1 methylation change exhibited different sensitivity according to the subfamily evolutionary ages, with stronger effects on the oldest L1-M and Alu J in NHBE, and oldest L1-M and youngest Alu S in NHEK. CONCLUSIONS: These results demonstrate that the differential susceptibility of PM-induced hypomethylation of Alu and LINE1 depends upon RE evolutionary age and PM type.

Association Between Obesity and Cardiovascular Disease in Elderly Patients With Diabetes: A Retrospective Cohort Study.

CONTEXT: Some studies have suggested that patients with type 2 diabetes mellitus (T2DM) concomitant with obesity have better clinical outcomes than normal-weight patients with T2DM. OBJECTIVE: We evaluated associations among obesity, cardiovascular disease (CVD) events, and mortality in elderly patients with T2DM without CVD. METHODS: This retrospective observational study from 2009 to 2017, with a mean follow-up of 7.26 years, included 249 903 elderly (≥ 65 years) patients with T2DM and no preexisting CVD from the Korean National Health Information Database. We categorized subjects according to body mass index (BMI) and waist circumference (WC) and analyzed a composite of stroke, myocardial infarction, and all-cause death using Cox proportional hazards regression analysis, adjusting for baseline covariates. RESULTS: The incidence rate of composite primary outcomes was 30.95/1000 person-years. The primary outcome risk had an L-shaped and a U-shaped association with BMI and WC, respectively. In the multivariable Cox proportional hazard models, the risk of primary composite outcomes in the highest BMI group (≥ 30 kg/m2; hazard ratio [HR] = 0.824; 95% CI, 0.794-0.855) was lower than in the normal BMI group (≥ 18.5 and < 23 kg/m2). Conversely, that in the highest WC group (≥ 100 cm/≥ 95 cm; men/women; HR = 1.434; 95% CI, 1.384-1.486) was higher than in the normal WC group (< 90 cm/< 85 cm; men/women). CONCLUSION: Our study with elderly patients with diabetes results suggest that while BMI is an inadequate risk indicator for outcomes related to obesity, WC is a suitable alternative.

Formation of the Tertiary Sulfonamide C(sp3)-N Bond Using Alkyl Boronic Ester via Intramolecular and Intermolecular Copper-Catalyzed Oxidative Cross-Coupling.

A synthetic strategy for the formation of C(sp3)-N bonds, particularly through a copper-catalyzed oxidative cross-coupling, is rare. Herein, we report a novel synthetic approach for the preparation of tertiary sulfonamides via copper-catalyzed intra- and intermolecular oxidative C(sp3)-N cross-coupling reactions. This method allows the utilization of the readily available C(sp3)-based pinacol boronate as a substrate and the tolerance of a wide range of functional groups under mild reaction conditions. The success of this strategy relies on the unprecedented additive effects of silanol and NaIO4.

Blood Pressure and Cardiovascular Disease in Older Patients With Diabetes: Retrospective Cohort Study.

Background Blood pressure (BP) targets in elderly patients with diabetes remain unclear. We evaluated the association between BP and cardiovascular disease in elderly patients with diabetes without cardiovascular disease or heart failure. Methods and Results We performed a retrospective cohort study of 225 563 elderly (aged ≥65 years) patients with diabetes without cardiovascular disease or heart failure from 2009 to 2017 using the National Health Information Database. We divided the participants by systolic BP (SBP) and diastolic BP. Primary composite outcomes were stroke, myocardial infarction, heart failure, and all-cause death analyzed by Cox proportional hazards regression analysis adjusted for baseline covariates. During a median follow-up of 7.76 years, the incidence rate of primary composite outcomes was 26.62 per 1000 person-years. In multivariable Cox proportional hazard modeling, the risk of the primary outcome had a U-curved association with SBP/diastolic blood pressure with a nadir between 120 and 129 mm Hg/65 and 69 mm Hg, respectively. Hypertension medication was associated with lower risk of primary composite outcomes in SBP ≥140 mm Hg (P for interaction for SBP <0.001) and diastolic blood pressure ≥90 mm Hg (P for interaction for diastolic blood pressure=0.018). In participants aged ≥80 years, SBP ≥160 mm Hg was only a marginally higher risk for primary composite outcomes (hazard ratio=1.11; 95% CI, 0.98-1.24). Conclusions In this large sample of older Korean patients with diabetes, cardiovascular events were more common in people with resting SBP or diastolic BP ≥140 or 95 mm Hg, respectively, and also more common in people with resting SBP or diastolic BP <120 or 65 mm Hg, respectively.

Framingham Risk Score Assessment in Subjects with Pre-diabetes and Diabetes: A Cross-Sectional Study in Korea.

BACKGROUND: This study aimed to evaluate cardiovascular risk in subjects with pre-diabetes and diabetes in Korea. METHODS: In this pan-Korean, non-interventional, cross-sectional study, data were collected from medical records of 10 hospitals between November 2013 and June 2014. Subjects (aged ≥40 years) with medical records of dysglycemia and documentation of total cholesterol level, high-density lipoprotein cholesterol level, systolic blood pressure, and smoking status in the past 6 months were included. The primary endpoint was to determine the Framingham risk score (FRS). The relationships between FRS and cardiovascular risk factors, glycated hemoglobin, and insulin usage were determined by multiple linear regression analyses. RESULTS: Data from 1,537 subjects with pre-diabetes (n=1,025) and diabetes (n=512) were analyzed. The mean FRS (mean±standard deviation) in subjects with pre-diabetes/diabetes was 13.72±8.77. FRS was higher in subjects with diabetes than pre-diabetes (P<0.001). FRS in men with pre-diabetes was comparable to that in women with diabetes (13.80±7.37 vs. 13.35±7.13). FRS was elevated in subjects who consumed alcohol (2.66, P=0.033) and with obesity-class II (6.10, P=0.015) among subjects with diabetes (n=199), and was elevated in patients with left ventricular hypertrophy (11.10, P=0.005), those who consumed alcohol (3.06, P=0.000), were pre-obese (3.21, P=0.002), or were obesity-class I (2.89, P=0.002) among subjects with pre-diabetes (n=306) in comparison to subjects without these coexisting risk factors. CONCLUSION: Overall, Korean subjects with pre-diabetes and diabetes have an increased cardiovascular risk, which is significantly higher in those subjects with diabetes than with pre-diabetes. The present data can be used to develop measures to prevent and manage cardiovascular complications in Koreans with impaired glucose metabolism.

Cisplatin Resistance in Epstein-Barr-Virus-Associated Gastric Carcinoma Acquired through ATM Methylation.

Epstein-Barr-virus-associated gastric carcinoma (EBVaGC), first reported in 1992, currently accounts for 10% of all gastric carcinoma worldwide. EBVaGC has unique DNA hypermethylation phenotypes that allow for higher proportions of DNA methylation than any other gastric cancer. CpG islands in the gene promoter region are one of the major regions in which DNA methylation controls gene transcription. Despite cisplatin-based chemotherapy being one of the standard treatment regimens for advanced gastric cancer, including EBVaGC, cisplatin alone or in combination with 5-fluorouracil has been limited by its less potent anticancer activity and the occurrence of cisplatin resistance. Accordingly, the current study evaluated the anticancer activities of a combination of cisplatin and 5-Azacytidine (5-AZA) against EBVaGC. Our findings showed that cisplatin upregulated the DNMT3A gene, whereas shRNA-targeted removal of DNMT3A mRNA contributed to cisplatin-mediated EBV lytic reactivation. Moreover, the removal of DNMT3A mRNA upregulated the ATM gene through DNA demethylation on the ATM promoter. Furthermore, CRISPR/Cas9-targeted removal of the ATM gene resulted in significantly reduced cell susceptibility and EBV lytic reactivation by a combination of cisplatin and DNMT3A inhibitor 5-AZA. Finally, 5-AZA exhibited a synergistic effect with cisplatin in anti-EBV and anti-EBVaGC activities by increasing drug susceptibility and EBV lytic reactivation. The aforementioned results suggest that cisplatin combined with DNA methylation inhibitors could be a novel therapeutic approach for EBVaGC.

Clonal dynamics in early human embryogenesis inferred from somatic mutation.

Cellular dynamics and fate decision in early human embryogenesis remain largely unknown owing to the challenges of performing studies in human embryos1. Here, we explored whole-genomes of 334 single-cell colonies and targeted deep sequences of 379 bulk tissues obtained from various anatomical locations of seven recently deceased adult human donors. Using somatic mutations as an intrinsic barcode, we reconstructed early cellular phylogenies that demonstrate (1) an endogenous mutational rate that is higher in the first cell division but decreases to approximately one per cell per cell division later in life; (2) universal unequal contribution of early cells to embryo proper, resulting from early cellular bottlenecks that stochastically set aside epiblast cells within the embryo; (3) examples of varying degrees of early clonal imbalances between tissues on the left and right sides of the body, different germ layers and specific anatomical parts and organs; (4) emergence of a few ancestral cells that will substantially contribute to adult cell pools in blood and liver; and (5) presence of mitochondrial DNA heteroplasmy in the fertilized egg. Our approach also provides insights into the age-related mutational processes and loss of sex chromosomes in normal somatic cells. In sum, this study provides a foundation for future studies to complete cellular phylogenies in human embryogenesis.