Obesity as a mediator linking sleep-disordered breathing to both impaired fasting glucose and type 2 diabetes.

PURPOSE: To examine whether or not associations between sleep-disordered breathing (SDB) and impaired fasting glucose and type 2 diabetes are mediated by obesity. METHODS: We used cross-sectional data including participants from the Multi-Ethnic Study of Atherosclerosis (MESA). SDB, including obstructive sleep apnea (OSA), hypoxia and sleep fragmentation, was evaluated by polysomnography. Further, five obesity measures related to overall obesity and central obesity were assessed. Mediation analysis was conducted to explore the mediating effect of obesity on these relationships between SDB and impaired fasting glucose and type 2 diabetes. RESULTS: Among 1615 participants, OSA and hypoxia, including apnea hypopnea index (AHI) ≥ 15, percent of total sleep time (TST) with SaO2 < 90% (TST90), oxygen desaturation index (ODI), and lowest oxygen saturation (SaO2), were significantly associated with impaired fasting glucose and type 2 diabetes. In addition, mean SaO2 was also associated with impaired fasting glucose. Mediation analysis showed that these relationships were significantly mediated by all five obesity measures, where central obesity had greater mediating effect than overall obesity. Proportion of mediation of obesity ranged from 21.5 to 62.5% for impaired fasting glucose and 25.85 to 71.6% for type 2 diabetes, with substantial differences found in the subgroup analysis by gender or race/ethnicity. The consistency of the mediating effect was demonstrated across multiple measures of SDB, obesity, and glucose metabolism. CONCLUSION: Obesity, especially central obesity, may play a critical role in the pathway where SDB, including OSA and hypoxia, increases the occurrence of impaired fasting glucose and type 2 diabetes. Weight management is important for patients with SDB to prevent type 2 diabetes.

Evaluating the effects of microparticle addition on mycelial morphology, natural yellow pigments productivity, and key genes regulation in submerged fermentation of Monascus purpureus.

Morphology plays an important role in fungal fermentation and secondary metabolites biosynthesis. One novel technique, microparticle-enhanced cultivation was successfully utilized to control the morphology of Monascus purpureus precisely and enhance the yield of yellow pigments. The production of yellow pigments increased to 554.2 U/ml when 4 g/L 5000 mesh talc added at 24 h. Field emission scanning electron microscope observation indicated that the actual effect depends on the properties of microparticle. Sharp-edged microparticles showed better stimulatory effects than smooth, round-shaped ones. Particle size analysis, scanning electron microscope, and cell integrity evaluation proved obvious morphological changes were induced by talc addition, including smaller mycelial size, rougher hyphae, and decreased cell integrity. Furthermore, the expression levels of MrpigG, MrpigD, MrpigE, and MrpigH were significantly upregulated by the addition of talc. It indicated that the microparticle could not only affect the mycelial morphology, but also influence the expression levels of key genes in biosynthetic pathway of Monascus yellow pigments.

Computed tomography evaluation of extensive intravenous angioleiomyoma: a case report.

BACKGROUND: Uterine angioleiomyoma is a rare variant of leiomyoma, and the main therapy is complete surgery. This study introduces the benefit of three-dimensional computed tomography reconstruction for preoperative preparation. CASE PRESENTATION: A 50-year-old woman presented because of chest distress after activity, with worsening symptoms. After examination, the final diagnosis was uterine angioleiomyoma. The tumour originated in the uterus; grew into the right iliac vein; coursed along the iliac vein, inferior vena cava, and right atrium; and finally invaded the right ventricle. To best complete the surgery, a multidisciplinary surgery was selected. Before the surgery, a three-dimensional computed tomography reconstruction model was created to assess the tumour status, and this model enabled the surgery to be completed successfully. CONCLUSION: Three-dimensional computed tomography reconstruction is of great significance for the preoperative diagnosis of uterine angioleiomyoma and the formulation of surgical treatment plans. Based on its vivid images, surgeons can perform operations more effectively and safely.

The Effects of High-Intensity Interval Exercise and Hypoxia on Cognition in Sedentary Young Adults.

Background and Objectives: Limited research has evaluated the effects of acute exercise on cognition under different conditions of inspired oxygenation. Thus, the purpose of this study was to examine the effects of high-intensity interval exercise (HIE) under normoxia (inspired fraction of oxygen (FIO2): 0.209) and moderate hypoxia (FIO2: 0.154) on cognitive function. Design: A single-blinded cross-over design was used to observe the main effects of exercise and oxygen level, and interaction effects on cognitive task performance. Methods: Twenty inactive adults (10 males and 10 females, 19⁻27 years old) performed a cognitive task (i.e., the Go/No-Go task) before and immediately after an acute bout of HIE under normoxic and hypoxic conditions. The HIE comprised 10 repetitions of 6 s high-intensity cycling against 7.5% body weight interspersed with 30 s passive recovery. Heart rate, peripheral oxygen saturation (SpO2) and rating of perceived exertion were monitored. Results: The acute bout of HIE did not affect the reaction time (p = 0.204, η² = 0.083) but the accuracy rate decreased significantly after HIE under both normoxic and hypoxic conditions (p = 0.001, η² = 0.467). Moreover, moderate hypoxia had no influence either on reaction time (p = 0.782, η² = 0.004) or response accuracy (p = 0.972, η² < 0.001). Conclusions: These results indicate that an acute session of HIE may impair response accuracy immediately post-HIE, without sacrificing reaction time. Meanwhile moderate hypoxia was found to have no adverse effect on cognitive function in inactive young adults, at least in the present study.

Relationship Between Physical Activity Patterns and Metabolic Syndrome Among Male Coal Miners of Shanxi Province in China.

OBJECTIVE: This study aimed to investigate the relationship between metabolic syndrome (MetS) and physical activity (PA) in different domains among male coal miners of Shanxi Province in China. METHOD: The study was conducted from July 2013 to December 2013. A two-stage stratified cluster sampling method was used. Data regarding the general information of participants were collected by well-trained interviewers. MetS was defined according to IDF criteria. Self-reported PA was obtained with the IPAQ and categorized into three tertiles of intensity levels across occupation, transportation, household, and leisure-time domains. Univariate and multiple logistic regression analysis were applied to compute the odds ratios and their 95% confidence interval (CI). RESULTS: A total of 3076 males aged 18-65 years old were recruited in this cross-sectional study. The prevalence of MetS was 40.5% in the study subjects. The percentages of vigorous-intensity PA in MetS and non-MetS groups were 70.07% and 62.92%, respectively. Participants spent most of their time on occupation (2034 MET-min/w) and transportation (693MET-min/w) domains. Higher-intensity levels in occupation domains were significantly associated with lower risk of MetS (OR: 0.759, 95% CI: 0.633-0.911; OR: 0.627, 95% CI: 0.516-0.762). CONCLUSIONS: Across four types of workers, the relationships between PA domains and MetS were different. For underground and underground auxiliary workers, the negative relationship was found between occupation PA and MetS. For office workers, the negative relationship was found between household PA and MetS. For ground workers, only leisure-time PA had positively related to MetS.

[Application of reverse molecular docking technology in target prediction, active ingredient screening and action mechanism exploration of traditional Chinese medicine].

Traditional Chinese medicine(TCM) modernization has gradually become a worldwide trend. Reverse docking technology has also gradually become a useful tool for TCM modernization. It involves docking a small-molecule drug in the potential binding cavities of a set of clinically relevant macromolecular targets. Detailed analysis of the binding characteristics was used for the ranking of the targets according to the tightness of binding. This process can be used to potentially identify the novel molecular targets for the drug which may be relevant to its mechanism of action or side effect. In order to explore the action mechanism, screen the active ingredients and seek the treating target of TCM, reverse molecular docking technology has been widely used and has achieved remarkable results in recent years. In this review, we summarized the application of reverse molecular docking technology in the target seeking, active ingredients screening and potential mechanism exploration of TCM, which may provide more scientific basis for the clinical research and development of new herbal drugs.

[Expression and clinical significance of Dyrk1b in the specimens and cells of cervical lesions].

OBJECTIVE: To detect and explore the expression and clinical significance of dual specificity tyrosine phosphorylation regulated kinase1b (Dyrk1b) in the specimens and cells of cervical lesions. METHODS: (1) All the data were collected from 75 patients with cervical cancer and 52 cases with squamous intraepithelial lesion (SIL) admitted in the First Affiliated Hospital of Dalian Medical College during Jan. 2011 to Dec. 2013 and confirmed by pathological examination, included 60 cases of stage Ⅰ and 15 cases of stage Ⅱ, 12 cases with low-grade squamous intraepithelial lesion (LSIL) and 40 cases with high-grade squamous intraepithelial lesion (HSIL). While, 28 cases with chronic cervicitis were chosen as the control group. The protein expression of Dyrk1b was detected by immunohistochemistry among the four groups. (2) The expression of Dyrk1b in HeLa and SiHa cells were detected by western blot method and the expression of Dyrk1b protein were also detected after treatment of AZ191 (5, 10 µmol/L) for 48 hours in HeLa and SiHa cells. (3) The cellular survival and proliferation of HeLa and SiHa cells treated by different concentrations of AZ191 (2.5, 5, 10, 25, 50, 100 µmol/L) for 48 hours were detected by methyl thiazolyl tetrazolium (MTT) assay. (4) The rate of apoptosis of HeLa and SiHa cells was detected by flowcytometry after treatment of AZ191 (5, 10 µmol/L) for 48 hours. RESULTS: (1) The positive rates of Dyrk1b protein in chronic cervicitis, LSIL, HSIL and cervical squamous cancer by immunohistochemistry were 11%(3/28), 1/12, 42% (17/40) and 71% (53/75), respectively. The expression of Dyrk1b in cervical squamous cancer and HISL were higher than those in LSIL and chronic cervicitis (P<0.01), there were significant difference between cervical squamous cancer and HSIL, or between HSIL and LSIL (all P<0.05), while there were not significant difference between LSIL and chronic cervicitis (P>0.05). Expression of Dyrk1b was correlated with stromal invasion depth of cervical cancer (P<0.05), but not with age, clinical stage, lymph node metastasis, and serum squamous cell carcinom antigen (SCC-Ag) levels (all P>0.05). (2) Dyrk1b protein was expressed in different levels in HeLa and SiHa cells, and the expression of Dyrk1b was decreased gradually as the increased of the concentration of AZ191 in both HeLa and SiHa cells by treatment of AZ191 for 48 hours. (3) Different concentration of AZ191 treated on cervical cancer cells could inhibit the cellular proliferation and induce cell apoptosis in a concentration-dependent manner (P<0.01), concomitant to the decreased cell survival rate. The apoptosis rate of HeLa and SiHa were increased significantly after 10 µmol/L AZ191-treatment for 48 hours, but no any difference induced by 5 µmol/L AZ191-treatment compared to control group. Also,there was no any difference between Hela and SiHa cells in either inhibitory effect or apoptosis rate induced by AZ191. CONCLUSIONS: Dyrk1b is over-expressed in either specimens or cells of cervical cancer. The expression of Dyrk1b protein in cervical lesions is increased as the progression of disease. Dyrk1b inhibitor AZ191 could inhibit cellular proliferation and induce apoptosis in a concentration-dependent manner in cervical cancer cells.

Elevated GAPDH expression is associated with the proliferation and invasion of lung and esophageal squamous cell carcinomas.

Glyceraldehyde-3-phosphate dehydrogenase, is one of the most investigated housekeeping genes and widely used as an internal control in analysis of gene expression levels. The present study was designed to assess whether GAPDH is associated with cancer cell growth and progression and, therefore may not be a good internal control in cancer research. Our results from clinical tissue studies showed that the levels of GAPDH protein were significantly up-regulated in lung squamous cell carcinoma tissues, compared with the adjacent normal lung tissues, and this was confirmed by western blotting and immunohistochemistry. GAPDH knockdown by siRNA resulted in significant reductions in proliferation, migration, and invasion of lung squamous carcinoma cells in vitro. In a nude mouse cancer xenograft model, GAPDH knockdown significantly inhibited the cell proliferation and migration/invasion in vivo. In summary, GAPDH may not be an appropriate internal control for gene expression studies, especially in cancer research. The role of GAPDH in cancer development and progression should be further examined in pre-clinical and clinical studies.

Non-adiabatic conformation distortion charge transfer enables dual emission of thermally activated delayed fluorescence and room temperature phosphorescence.

In this work, we report for the first time that thiophenol-substituted naphthalimide can achieve thermally activated delayed fluorescence (TADF) and room temperature phosphorescence (RTP) simultaneously through non-conjugated flexible connection. Herein, we explain that the enhancement of intersystem crossing (ISC) between the singlet excited state and triplet excited states in NISPh is mainly caused by the non-adiabatic conformation distortion charge transfer (CDCT) of the excited states. More precisely, CDCT results in the conformation matching and energy barrier decrease between the excited states. In addition, the electronic and vibration coupling is further enhanced in NISPh. Our work substantiates a rational design strategy for the development of simple purely organic materials to achieve dual emission of TADF and RTP.

The mediating effect of 24-h time-use behaviors on the relationship between depression and mortality: A compositional mediation analysis for survival outcomes.

BACKGROUND: A compositional mediation model of survival outcomes was established to explore whether 24-h time-use behaviors mediate the relationship between depression and mortality. METHODS: 4137 adults from the National Health and Nutrition Examination Survey (NHANES 2005-2006) were followed up to 2019. Cox proportional hazards regression model was used to estimate the total effect of depression on mortality. Compositional data analysis was used to examine the relationship between 24-h time-use compositions and mortality. Furthermore, we constructed a compositional mediation model for survival outcomes to investigate the mediating effect of 24-h time-use behaviors on depression and mortality. RESULTS: Compared with participants without depression, depressive patients had a significantly higher risk of overall mortality (HR = 1.49, 95 % CI: 1.25,1.79), cardiovascular disease -specific mortality (HR =1.89, 95 % CI: (1.37,2.63)) and mortality from causes other than cardiovascular disease or cancer (HR = 1.62, 95 % CI: (1.25,2.08)). Physical activity, especially moderate-to-vigorous physical activity, significantly mediated the relationship between depression and all-cause and CVD-specific mortality. LIMITATIONS: Despite being a cohort study, the exposure and mediatiors were measured at the baseline. Further research is necessary to require a temporal order between the exposure and mediating variables. CONCLUSIONS: Our findings indicate that 24-h time-use behaviors link depression to mortality. In particular, increasing the time spent on physical activity can reduce the risk of death in patients with depression. This finding provides potential interventions for reducing the risk of death in patients with depression.

Annexin A7 suppresses lymph node metastasis of hepatocarcinoma cells in a mouse model.

BACKGROUND: Hepatocellular carcinoma (HCC) is one of the leading causes of cancer death in China. This study investigated the effects of Annexin A7 (ANXA7) on the inhibition of HCC lymph node metastasis in a mouse model. METHODS: The stable knockup and knockdown of Annexin A7-expressing HCC cells using Annexin A7 cDNA and shRNA vectors, respectively, were injected into a mouse footpad to establish primary and metastatic tumors in mice. On the 14th, 21st, and 28th days after HCC cells inoculation, the mice were sacrificed for inspection of primary and secondary tumors and immunohistochemistry of Annexin A7 expression. RESULTS: The lymph node metastasis rate of the FANXA7-control group was 77%, and the lymph node metastasis rate of the FANXA7-down group was 100% (p<0.05). In contrast, the lymph node metastasis rate of the PANXA7-up group was 0% and that of the PANXA7-control group was 36% (p<0.05). Furthermore, immunohistochemistry experiments revealed that the subcellular localization of Annexin A7 protein in both primary and lymph node-metastasized tumors was mainly in the cytosol. In addition, the expression of the 47 kDa and 51 kDa isoforms of Annexin A7 protein changed during tumor progression. CONCLUSION: This study indicated that Annexin A7 expression was able to inhibit HCC lymph node metastasis, whereas knockdown of Annexin A7 expression significantly induced HCC metastasis to local lymph nodes.

Enhanced control structure design for an industrial off-gas system: Simple reconfigurations benefit the economy.

For control structure design of the industrial off-gas benchmark system, application of the Skogestad's state-of-art design procedure has suggested the scrubber inlet pressure (P si in the roaster) and one of the fan speeds (N fan1 or N_fan2 in the furnace) as the self-optimizing controlled variables CVs. In this study, we stress and advocate the gSOC-plus-BAB approach as an enhanced design toolkit for the classical and systematical design procedure. The gSOC (global self-optimizing control) is able to efficiently solve measurement combinations as CVs with improved economic performances, while the BAB (branch and bound) algorithm serves to fast screen promising measurement subsets for large-scale problems. Using the enhanced design for the off-gas system, our new findings are to control the combination of roaster's ID fan outlet pressures, 0.494P IDfan1+0.506P IDfan2 (setpoint: -257.04 Pa), and the furnace's fan pressure difference, P IDfan1- P IDfan2 (setpoint: 0). Such simple reconfigurations can dramatically reduce the average economic loss by 53.3% for the roaster and even achieve perfect optimal control for the furnace. Both steady state and dynamic evaluations are carried out to validate the reconfigured control structures. © 2017 Elsevier Inc. All rights reserved.

Peer champions responses to nudge-based strategies designed to reduce prolonged sitting behaviour: Lessons learnt and implications from lived experiences of non-compliant participants.

Occupational sedentariness is problematic for office-based workers because of their prolonged sitting periods and the advent of technology which reduces work-based movement. A common workplace strategy to deal with this preventable health risk is to have workers engage in brief movement breaks throughout the workday. To date, the use of interventions underpinned by individual self-regulation has had less than optimal impact on changing workers sedentary work behaviours. An alternative design for workplace interventions is the use of nudge theory. Nudge theory incorporates strategies that are delivered at the point of choice designed to influence individual decision making regarding alternative behaviour options. In this study, desk-based workers were exposed to two nudge strategies which suggested alternative behaviours of regular standing and taking movement breaks during work periods to the default behaviours of prolonged sitting and sedentary work behaviour. A small group of women managers who served as peer champions (n = 6), withdrew early from the study, and then took part in an exit interview to gain an understanding of their experiences of being exposed to the two nudge strategies. Verbatim transcripts were analysed using inductive, reflexive thematic analysis. Two major themes with seven second order themes central to their experiences were extracted: facilitative behaviour and feelings (advocacy, acceptance & facilitative burden) and dysfunctional behaviours and feelings (dysfunctional behaviour & feelings, control, reactance & presenteeism). Participants initially perceived a positive exchange associated with exposure to nudge strategies. Yet, participants' emotional connection to their work roles and behaviour were perceived as a negative exchange. Participants cited numerous maladaptive feelings because of a perception of incongruency with the established work normative behaviour. These findings reveal that nudge strategies of reduced choice and social norms are viable, but perceptions of monitoring can moderate adherence.

Retraction Notice to: A Novel Mechanism of Doxorubicin Resistance and Tumorigenesis Mediated by MicroRNA-501-5p-Suppressed BLID.

[This retracts the article DOI: 10.1016/j.omtn.2018.06.011.].

Expression patterns of prion protein gene in differential genotypes sheep: quantification using molecular beacon real-time RT-PCR.

Determination of the transcription level of cellular prion protein (PrP(C)) is essential for understanding its role in organisms and revealing mechanism of susceptibility and resistance to scrapie. However, the expression of prion protein (PrP) mRNA in sheep has not been quantified in great detail in digestive tract which is important during scrapie spread through oral route. Herein, we report on measurement of sheep PrP mRNA using absolute quantitative real-time RT-PCR. Total RNA was isolated from five different regions of the central nervous system (CNS), four regions of lymphoid system, eleven regions of digestive tract, and two reproductive organ tissues of eight sheep of two different genotypes (ARR/ARQ and ARH/ARQ) and PrP mRNA was quantified by real-time RT-PCR using molecular beacon. The results showed that highest levels of PrP mRNA were expressed in thalamus and cerebrum (P < 0.01) of CNS examined, followed by cerebellum, spinal cord, and brain stem. In peripheral organs examined, lymph tissue showed moderate level of PrP expression similar to that in digestive tract and reproduction organs. PrP expression levels in the same tissue of different genotype sheep had significant variation. Our study provided the first detail, tissue-specific and genotype-specific data of PrP mRNA expression in sheep for further studies of pathogenesis of prion diseases.

The Road to the Beijing Winter Olympics and Beyond: Opinions and Perspectives on Physiology and Innovation in Winter Sport.

Beijing will host the 2022 Winter Olympics, and China strengthens research on various aspects to allow their athletes to compete successfully in winter sport. Simultaneously, Government-directed initiatives aim to increase public participation in recreational winter sport. These parallel developments allow research to advance knowledge and understanding of the physiological determinants of performance and health related to winter sport. Winter sport athletes often conduct a substantial amount of training with high volumes of low-to-moderate exercise intensity and lower volumes of high-intensity work. Moreover, much of the training occur at low ambient temperatures and winter sport athletes have high risk of developing asthma or asthma-related conditions, such as exercise-induced bronchoconstriction. The high training volumes require optimal nutrition with increased energy and dietary protein requirement to stimulate muscle protein synthesis response in the post-exercise period. Whether higher protein intake is required in the cold should be investigated. Cross-country skiing is performed mostly in Northern hemisphere with a strong cultural heritage and sporting tradition. It is expected that innovative initiatives on recruitment and training during the next few years will target to enhance performance of Chinese athletes in classical endurance-based winter sport. The innovation potential coupled with resourcing and population may be substantial with the potential for China to become a significant winter sport nation. This paper discusses the physiological aspects of endurance training and performance in winter sport highlighting areas where innovation may advance in athletic performance in cold environments. In addition, to ensure sustainable development of snow sport, a quality ski patrol and rescue system is recommended for the safety of increasing mass participation.

Thermally Activated Delayed Fluorescence Enabled by Reversed Conformational Distortion for Blue Emitters.

In this work, we present for the first time a general strategy via molecular reversed conformational distortion for thermally activated delayed fluorescence (TADF). A model purely organic compound named BNNIO with a common fluorophore flexibly linked to benzene by an oxygen atom is rationally designed and successfully synthesized. Moreover, the rate constant of reverse intersystem crossing reaches 2.34 × 104 s-1 as determined by transient spectroscopy. As a result, TADF emission of BNNIO is observed with a photoluminescence quantum yield of 90.72% and a lifetime of 84.76 µs at 415 nm. This universal regulation strategy undoubtedly opens a new avenue for the development of novel purely organic blue light-emitting materials.

Expression of BMP7 in cervical cancer and inhibition of epithelial­mesenchymal transition by BMP7 knockdown in HeLa cells.

The aim of the present study was to investigate the expression of bone morphogenetic protein 7 (BMP7) in cervical cancer tissues, the effect of BMP7 on the proliferation, migration and epithelial­mesenchymal transition (EMT) of cervical cancer HeLa cells and the possible mechanism involved. Immunohistochemistry was used to stain the cervical cancer tissues and benign or precancerous lesions. Lentivirus containing BMP7 knockdown was transfected in HeLa cells and western blotting was performed to analyze BMP7 expression. At the same time, the influence of BMP7 knockdown on the expression of phosphorylated (p)­mothers against decapentaplegic homolog 1/5/9 and EMT­related markers [epithelial­cadherin, neural­cadherin, Vimentin, Snail and Slug] was detected. Cell Counting Kit­8 was used to detect cell proliferation. Transwell migration and invasion assays were performed to measure cell invasion and migration. The cell cycle was detected by flow cytometry. Compared with normal cervical epithelial and paracancerous cells, the positive rate of BMP7 expression in cervical cancer tissues was significantly increased. As compared with the control group, the expression of BMP7 was decreased in HeLa cells transfected with lentivirus. The knockdown of BMP7 in cervical cancer HeLa cells inhibited cell proliferation, migration and invasion, resulted in G1 cell cycle arrest and reversed the EMT process. In addition, the expression of p­Smad1/5/9 was significantly decreased in HeLa cells with BMP7 knockdown. BMP7 is expected to be a possible target for the treatment of cervical cancer.

Facile synthesis of highly efficient fluorescent carbon dots for tetracycline detection.

Rampant use of tetracycline in animal feed is a threat to food security, the environment, and human health because of the risk of drug residues. Therefore, it is necessary to establish a sensitive, efficient, and reliable method for qualitative and quantitative detection of tetracycline. In this paper, we synthesized fluorescent carbon dots (FCDs) by thermal cracking of crab shell waste, and obtained a fluorescence quantum yield of 30%. Characterization of the FCDs by transmission electron microscopy, Fourier-transform infrared spectroscopy, ultraviolet visible absorption spectroscopy, and photoluminescence spectroscopy showed that they were fluorescent and evenly distributed with an average size of approximately 10 nm. We designed a sensitive probe for detecting tetracycline using the fluorescence intensity change of the FCDs. This method is sensitive, inexpensive, and environmentally friendly. The concentration of tetracycline was examined by comparing the fluorescence intensities of the FCDs before and after tetracycline addition. The limit of detection for tetracycline was 0.005 mg/L (signal-to-noise ratio = 3), which is promising for method development.

METTL3 serves an oncogenic role in human ovarian cancer cells partially via the AKT signaling pathway.

Methyltransferase-like 3 (METTL3) has been identified as a methyltransferase responsible for N6-methyla-denosine (m6A) modification of mRNA. METTL3 functions in tumorigenesis and tumor development by promoting the translation of oncoproteins; however, the role of METTL3 in ovarian cancer has not been extensively studied. The present study performed immunohistochemistry to detect METTL3 expression levels in 52 samples of ovarian cancer tissue paired with corresponding paracancerous tissue. RNA interference was conducted to downregulate the expression levels of METTL3 in the SKOV3 and OVCAR3 ovarian cancer cell lines. Reverse transcription-quantitative PCR and western blot analysis demonstrated the effects of METTL3 knockdown on mRNA and protein levels, respectively. CCK-8, colony formation, apoptosis and Transwell assays were also performed. The results demonstrated that METTL3 exhibited significantly higher expression levels in ovarian cancer tissues compared with corresponding paracancerous tissue. High METTL3 expression levels were associated with large tumors, lymph node metastasis and high pathological grade. Cell proliferation analysis revealed that METTL3 knockdown reduced the proliferation and clonogenic ability of SKOV3 and OVCAR3 cells. Apoptotic rates were increased in METTL3-silenced ovarian cancer cells, which may have been mediated by the activation of the mitochondrial apoptosis pathway, and METTL3 knockdown reduced cell invasion. METTL3 knockdown downregulated the phosphorylation levels of AKT and the expression of the downstream effector Cyclin D1. These results suggested that METTL3 may serve an oncogenic function in the progression of human ovarian cancer cells partially through the AKT signaling pathway, indicating that METTL3 may be a potentially novel therapeutic target for the treatment of ovarian cancer.