A high resolution and high detection efficiency depth-encoding detector for brain positron emission tomography based on a 0.75 mm pitch scintillator array

The quantitative accuracy and precision of brain positron emission tomography (PET) studies can be considerably improved using dedicated brain PET scanners with a uniform high resolution and a high sensitivity across the brain volume. One approach to building such a system is to construct the PET scanner using depth-of-interaction (DOI) encoding detectors with finely segmented and thick crystal arrays. In this paper, the performance of a DOI PET detector based on two 16 × 16 arrays of 2 × 2 mm2 SiPMs coupled to both ends of a 44 × 44 array of 0.69 × 0.69 × 30 mm3 polished LYSO crystals was evaluated at different temperatures (-9°C, 0°C, 10°C, and 20°C) for brain PET applications. The pitch size of the LYSO array is 0.75 mm. The flood histograms show that all the crystal elements in the LYSO array can be resolved except some edge crystals, due to the limited light sharing. The average energy resolution, average DOI resolution, and average timing resolution across crystal elements are 21.1 ± 3.0%, 3.47 ± 0.17 mm, and 1.38 ± 0.09 ns, respectively, which were obtained at a bias voltage of 56.5 V and a temperature of 0°C.

High-impact exercise stimulated localised adaptation of microarchitecture across distal tibia in postmenopausal women

We provided evidence that a 6-month regular hopping exercise intervention can increase trabecular number and possibly trabecular volume fraction of the distal tibia. Our novel localised analysis demonstrated region-specific changes, predominantly in the anterior region, in postmenopausal women.

INTRODUCTION

The localisation of bone remodelling and microarchitectural adaptation to exercise loading has not been demonstrated previously in vivo in humans. The aim of this study is to assess the feasibility of using 3D image registration and high-resolution peripheral quantitative computed tomography (HR-pQCT) to investigate the effect of high-impact exercise on human trabecular bone variables and remodelling rate across the distal tibia.

METHODS

Ten postmenopausal women were recruited for 6-month unilateral hopping exercises, with HR-pQCT scans taken of both exercise leg (EL) and control leg (CL) for each participant before and after the intervention. A 3D image registration was used to ensure measurements were taken at the same region. Short-term reproducibility tests were conducted prior to the assessment using identical setup. The results were assessed comparing CL and EL, and interaction (time × leg) using a two-way repeated measures analysis of variance (RM-ANOVA).

RESULTS

Across the whole tibia, we observed significant increases in trabecular number (Tb.N) (+ 4.4%) and trabecular bone formation rate (tBFR) (3.3%), and a non-significant increase in trabecular bone volume fraction (BV/TV) (+ 1%) in the EL. Regional resorption was higher in the CL than the EL, with this difference being statistically significant at the lateral tibia. In the EL, tBFR was significantly higher in the anterior region than the medial but a trabecular bone resorption rate (tBRR) showed no significant regional variation. Conversely in the CL, both tBFR and tBRR were significantly higher in the anterior and lateral than the medial region.

CONCLUSION

We demonstrated that it was possible to detect exercise-related bone adaptation with 3D registration of HR-pQCT scan data. Regular hopping exercise increased Tb.N and possibly BV/TV across the whole distal tibia. A novel finding of the study was that tBFR and tBRR responses to loading were localised: changes were achieved by formation rate exceeding resorption rate in the exercise leg, both globally and at the anterior region where turnover was greatest.

TRIAL REGISTRATION

clinicaltrials.gov : NCT03225703.

Effect of glucocorticoid therapy on the prognosis of patients with severe and critical COVID-19: a single-center retrospective cohort study

OBJECTIVE

Coronavirus disease 2019 (COVID-19) has elevated mortality in severe and critical patients globally. This study examined the effect of glucocorticoids (GCS) on the time of virus clearance and absorption of lung lesions in severe and critical COVID-19 patients.

PATIENTS AND METHODS

Severe and critical COVID-19 cases diagnosed in Wuhan Pulmonary Hospital from January 7 to February 10, 2020 were analyzed. The generalized linear model was utilized to assess the effects of GCS therapy on the times of nucleic acid test turning negative and improved pulmonary imaging, respectively.

RESULTS

Of 66 patients, 51 (77.3%) and 15 (22.7%) were severe and critical cases, respectively, and aged 62 ± 11 years. A total of 58 patients (87.9%) tested negative, and 56 (84.8%) showed improved lung imaging. Age, thrombocytopenia, CD8 + T cell count, course of GCS therapy, and total dose were correlated with the time of nucleic acid test turning negative (p < 0.05), and sex was correlated with the time of initial pulmonary imaging improvement (p < 0.05). The time of nucleic acid test turning negative in individuals with GCS therapy course ≤ 10 days was shorter than that of the GCS therapy course > 10 days group (p=0.001). No statistical difference was found in the dose, course of GCS, and initial time of improved lung imaging.

CONCLUSIONS

Increasing the dose of GCS and prolonging the course of treatment do not shorten the time of nucleic acid test turning negative or improved absorption of pulmonary lesions. Thus, the rational use of GCS is particularly important.

The mechanism changes during bisphenol A degradation in three iron functionalized biochar/peroxymonosulfate systems: The crucial roles of iron contents and graphitized carbon layers

Three magnetic biochar nanocomposites named as C800-1, C800-2 and C800-3 with increased iron deposition amount, decreased graphitized degree and gradually destroyed graphitized carbon layers, respectively, were prepared using potassium ferrate as activator and corn straw as biomass. C800-1, C800-2 and C800-3 exhibited much different bisphenol A degradation effect in presence of peroxymonosulfate among which C800-3 owned the best catalytic performance. For the degradation mechanism, the dominant role of electron transfer pathway was gradually replaced by the SO₄^•- pathway with the increase of iron amount and the destruction of graphitized carbon layers. This work would provide a simple and feasible method, namely changing the ratio of potassium ferrate and biochar, to manipulate the radical and nonradical degradation pathway in PMS-based organic wastewater purification.

LncRNA DCST1-AS1 regulated cell proliferation, migration, invasion and apoptosis in gastric cancer by targeting miR-605-3p

OBJECTIVE

Gastric cancer (GC) is one of the most common cancers in the world, with a high incidence and a poor prognosis. A large number of lncRNAs have been demonstrated to play multiple important roles in cancer development and progression. LncRNA is usually used as ceRNA and forms a regulatory network with miRNA in gastric cancer. However, the function and regulatory network of lncRNA in gastric cancer have not been fully elucidated.

MATERIALS AND METHODS

The qRT-PCR assay was used to detect DCST1-AS1 and miR-605-3p expression. Western blot was applied to measure the protein expression of CDK4, cyclin D1, MMP-2, MMP-9, cleaved caspase 3, Bcl-2, Bax and β-actin. MTT assay and flow cytometry were performed to assess cell proliferation and apoptosis, respectively. Transwell migration and invasion assay were used to determine cell migration capacity and invasion ability. Luciferase reporter assay was applied to determine the relationship of DCST-AS1 and miR-605-3p in GC.

RESULTS

In this study, we found that DCST1-AS1 was highly expressed while miR-605-3p was low expressed in GC tissues and cells. Moreover, DCST1-AS1 expression negatively regulated miR-605-3p expression in GC. Functionally test demonstrated that knockdown of DCST1 inhibited cell proliferation, migration and invasion as well as promoted cell apoptosis in GC cells. Interestingly, miR-605-3p has been verified to be a target miRNA of DCST1-AS1 with luciferase reporter assay. More than that, the reverse experiment determined that the inhibition of miR-605-3p could alleviate the suppressive effects of low DCST1-AS1 expression on cell growth in GC.

CONCLUSIONS

We proved the regulatory network of lncRNA DCST1-AS1 for the first time, and also explored and found that lncRNA DCST1-AS1 regulated cell proliferation, migration, invasion and apoptosis by regulation of miR-605-3p, providing a new therapeutic target for gastric cancer treatment.

[Clinical characteristics and prognosis of Waldenström's macroglobulinemia: a clinical data report from a single center]

Objective: To summarize the clinical characteristics and prognosis of 51 patients with Waldenström's macroglobulinemia (WM) and evaluate the efficacy and adverse reactions of ibrutinib in the treatment of WM. Methods: We carried out a single-center retrospective study, including 51 patients with WM of our single center from November 2008 to October 2019. Results: The median age at diagnosis was 65 years with a male-to-female ratio of 2.64∶1. There were 9 (18%) , 21 (41%) , and 21 (41%) ISSWM stage low-, intermediate- and high-risk patients identified, respectively. A total of 27 (73%) patients harbored MYD88(L265P) mutation. The median follow-up time was 38.6 (0.3-120.0) months, the median progression free survival was 46.4 months, and the median overall survival was not reached. The overall remission and major remission rates of patients who received ibrutinib were 87% and 80%, respectively. The median time to achieve at least partial remission of patients treated with ibrutinib was 8 weeks, which was earlier than those treated with other drugs (P<0.05) . Conclusion: WM is often seen in elderly men. MYD88(L265P) had a high frequency in WM. The findings of our study validate the efficacy of ibrutinib monotherapy. Even in patients with advanced age and at high risk of ISSWM, the overall remission rate and major remission rate are high. Ibrutinib is a safe and effective therapy because of its rapid onset and rare serious adverse reactions.

Regulation of circadian behavioural output via clock-responsive miR-276b

Growing evidence indicates that microRNAs play numerous important roles. However, the roles of some microRNAs involved in regulation of circadian rhythm and sleep are still not well understood. In this study, we show that the miR-276b is essential for maintaining both sleep and circadian rhythm by targeting tim, npfr1 and DopR1 genes, with miR-276b deleted mutant flies sleeping more, and vice versa in miR-276b overexpressing flies. Through analysing its promoter, we found that mir-276b is responsive to CLOCK and regulates circadian rhythm through the negative feedback loop of the CLK/CYC-TIM/PER. Furthermore, miR-276b is broadly expressed in the clock neurons and the central complexes such as the mushroom body and the fan-shape body of Drosophila brain, in which up-regulation of miR-276b in tim, npfr1 and DopR1 expressing tissues significantly causes sleep decreases. This study clarifies that the mir-276b is very important for participating in regulation of circadian rhythm and sleep.

[Whole genomic copy number variation score: an indicator of potential diagnostic and prognostic value for lung adenocarcinoma]

Objective: To verify the value of whole genomic copy number variation (WGCNV) detection and scoring system in the diagnosis and prognosis of lung adenocarcinoma. Methods: Seventy-six lung adenocarcinoma specimens including ninety-one tumor samples and twenty adjacent non-tumor lung tissue samples were collected using Laser capture microdissection (LCM). Whole genomic amplification (WGA) was used to enrich DNA and construct a sequencing library for next generation sequencing (NGS). Changes of larger than 5Mb CNV in this study were analyzed and scored. The nuclear grading and score of tumor cells in the surgery and pleural effusion cytology of lung adenocarcinoma specimens were evaluated separately. For each case, we evaluated (1) nuclear size, (2) mitotic counts, (3) nuclear atypia, (4) atypical mitoses. The data of disease-free survive (DFS) and overall survive (OS) were collected for assessing the prognostic value of WGCNV score. Meanwhile, receiver operating characteristic (ROC) and area under curve (AUC) were used to define a cut-off value and evaluate the diagnostic significance in lung adenocarcinoma. Results: The WGCNV scores of twenty adjacent non-tumor lung tissue samples were treated as normal control and all of WGCNV scores of tumor samples range from 0 to 9.95, the median score was 2.7. The WGCNV scores were divided into three groups: low score group <1.74, medium score grade 1.74~4.23, high score grade >4.23. The WGCNV score was positively associated with the nuclear grade scoring (r=0.780 90, P<0.001). The result for evaluation of prognostic value of the WGCNV scores showed that comparing with low WGCNV score group, Hazard Ratio (HR) of medium score group was 4.11 (95%CI=0.72~23.57) and high score group was 2.07 (95%CI=0.30~14.12). These results suggested that the risks of the medium and high WGCNV score group elevated. According to the analysis results of ROC curve, when the cut off value was 0.01, the sensitivity and specificity for lung adenocarcinoma diagnosis were 97.8% and 95.0% respectively, the positive predictive value (PPV) and negative predictive value (NPV) were 99.0% and 90.1%, respectively, the AUC was 0.981. In the differentiation of adenocarcinoma in situ (AIS) and minimally invasive adenocarcinoma (MIA) group and invasive adenocarcinoma group, when the cut off value was 1.8, the sensitivity and specificity between the two groups were 78.1% and 94.4%, and the PPV and NPV were 98.0% and 52.0%, respectively, the AUC was 0.896. Conclusion: This study verifies that WGCNV scoring system has a potential diagnostic and prognostic value in lung adenocarcinoma.

[Clinical aspects of pregnancy-related lymphocytic hypophysitis]

Objective: To analyze clinical features, diagnosis, treatment and prognosis of pregnancy-related lymphocytic hypophysitis (LyH). Methods: The clinical data of 16 cases diagnosed as pregnancy-related LyH at Chinese PLA General Hospital between October 2010 and November 2019 were reviewed. Results: Sixteen patients were included (aged 20-40 years). All patients' symptoms occurred from the last 2 months of pregnancy to 12 months postpartum, with 6 cases in the third trimester and 10 cases during postpartum, and all the patients were diagnosed after delivery. Six patients had lymphocytic adenohypophysitis (LAH), 4 patients had lymphocytic infundibuloneurohypophysitis (LINH), 4 patients had lymphocytic panhypophysitis (LPH), and 2 had lymphocytic hypothalamitis. Eight patients presented with symptoms of intracranial space-occupying lesions, 14 patients had symptoms of anteriorpituitary hormone deficiencies, 9 patients had central diabetes insipidus (CDI), and 2 had hyperprolactinemia. Pituitary MRI showed that the pituitary presented with diffuse enlargement, pituitary stalk thickening, disappearing of high-intensity signals in posterior pituitary and space-occupying lesions in the infundibulum of hypothalamus. Nine patients were treated with immunosuppressive agent, 3 patients alleviated the space-occupying effects after surgery, and 4 patients recovered spontaneously. Fourteen patients were followed up with a period of 3-98 months. Four patients had a relapse, 2 patients had a complete remission, and 12 patients needed long-term hormone replacement therapy. Conclusions: Clinical manifestations of pregnancy-related LyH are diverse. LyH should be suspected in pregnant or postpartum women with a sellar mass to avoid missed diagnosis or misdiagnosis. Immunosuppressant therapy is effective. Overall, LyH patients have a favorable prognosis.

[Incidence of eating problems and related factors in children aged 1-6 years]

Objective: To analyze the incidence of eating problems and risk factors in children aged 1-6 years, and provide evidence for formulating relevant prevention and control strategies. Methods: From June to December 2019, two community health service centers and two kindergartens were randomly selected in Shunyi district of Beijing by using stratified random cluster sampling method. Self-designed questionnaires were used to collect data on individual information, family information, and the incidence of eating problems and related factors. Multivariable logistic regression analysis was conducted to identify related factors. Results: A total of 2 391 valid questionnaires were returned, the analysis result indicated that 1 432 children had at least one eating behavior problem, the incidence rate was 59.9%. The most common eating problem was inattention while eating (48.8%), followed by irregular eating position (14.0%), picky eaters (13.0%), excessive eating time (11.2%), excessive snacks intake (9.0%), and soup with rice (4.6%). The mother's education level, family income level, main caregivers and family members' attitudes toward child's eating were related factors for eating behavior problems in children. Mothers with high education level (OR=0.528, 95%CI: 0.431-0.647) and family with high income level (OR=0.656, 95%CI: 0.473- 0.909) were the protective factors for child's poor eating behaviors. Grandparent caring (OR=1.366, 95%CI: 1.151-1.622), coaxing or forcing child to eat (OR=1.581, 95%CI: 1.284-1.947) were the risk factors for child's poor eating behavior. Conclusion: The incidence of eating problems was high in children aged 1-6 years. It is necessary to strengthen the intervention in families with low-income and low-education levels and children raised by grandparents to reduce the incidence of poor eating behaviors in children.

[Current status of depression among workers in a petrochemical enterprise in Liaoning Province, China and related influencing factors]

Objective: To investigate the influencing factors for depression among workers in a petrochemical enterprise and the association of occupational stress and occupational environment with depression, and to provide a scientific basis for the improvement of mental health and the prevention and treatment of depression among workers in petrochemical enterprises. Methods: A cross-sectional study was performed in March 2018, and cluster sampling was used to select 1888 workers from a petrochemical enterprise in Liaoning Province, China for a questionnaire survey. A total of 1888 questionnaires were collected, among which there were 1521 usable questionnaires, with an effective recovery rate of 80.56%. The general status of the workers in this petrochemical enterprise was investigated, and Center for Epidemiologic Studies Depression Scale (CES-D) , Effort-Reward Imbalance (ERI) , and Perceived Work Environment (PWE) were used to evaluate depression, occupational stress, and occupational environment. Constituent ratio was used to describe the distribution of different demographic features, work conditions, and lifestyles among the workers in this petrochemical enterprise. One-way analysis of variance and the t-test were used to compare the scores of depressive tendency between the workers with different features. Pearson correlation analysis was used to investigate the correlation of occupational stress and occupational environment with depression. Multivariate hierarchical regression analysis was used to investigate the influencing factors for depression. Results: The score of depression tendency was 18.94±9.21 in the workers in this petrochemical enterprise, and the incidence rate of depression symptoms was 59.8% (909/1521) . The workers who were aged <35 years, lived alone or in widowhood, or had an income of ≤4000 yuan tended to have a high score of depression tendency. And ordinary workers, oil-refining workers, workers with night shift and non-fixed shift, and workers with a lack of physical exercise and low sleep quality tended to have a high score of depression tendency (P<0.05) . The dimensions of extrinsic and intrinsic efforts of occupational stress and severity of occupational environment were positively correlated with depression (r=0.254, 0.242, 0.274, P<0.01) . And the dimension of reward was negatively correlated with depression (r=-0.348, P<0.01) . The multivariate hierarchical regression analysis showed that occupational stress and occupational environment had a marked predictive effects on depression, with an explained variance of 18.4% and 12.1%, respectively. Conclusion: There is a high level of depression tendency among workers in petrochemical enterprises, and demographic features, work conditions, lifestyle, occupational stressors, and occupational environment factors are influencing factors for depression.

[Analysis of the HIV antibody screening results among the preoperative examination patients in Beijing Tongren Hospital from 2008 to 2018]

Objective: To understand the HIV antibody screening results among the preoperative examination patients in Beijing Tongren Hospital from 2008 to 2018. Methods: A retrospective analysis of the HIV antibody screening data of thepreoperative examination patients from 2008 to 2018 in Beijing Tongren Hospital was performed with software SPSS19.0. Trend chi-square was used to analyze the positive rate, age, marital status, household registration and so on. Results: Among the 750 013 clinical patients, 428 (0.057%) cases were screened anti-HIV positive and 370(0.049%) cases were confirmed anti-HIV positive when detected with western blotting.Most of the HIV-infectedindividuals were non-Beijing nationality, accounting for 60.27%.Among the 370 HIV-infected patients, there were 334 males (90.27%) and 36 females (9.73%). The age was distributed mainly between 20-40 years old (62.43%), secondly between 40-60 years old (28.65%).361 (97.57%)HIV-infected cases were transmitted by the sex and the MSM men increased from 2008 to 2018 (trend χ²=7.307, P=0.007). There were 22 cases (5.95%) with HBsAg positive, 11 cases (2.97%) with anti-HCV positive. Among the 159 HIV-positive patients (42.97%) companied with syphilis specific antibody positive, there were 64 cases (17.30%) with TRUST tests positive. Additionally, 178 (48.11%) HIV-infected patientsfirst visited doctors because of ocular disease in the hospital; secondly, 71 (19.19%) HIV-infected patientsfirst visited the dermatology. Conclusions: The number of HIV-infected patientsmarkedly increased from 2008 to 2018. The sexual transmission is still the main pathway for HIV infection, particularly homosexual transmission. Moreover, the results indicate that it is necessary to detect HIV antibody for the ocular disease patients.

PINK1 in normal human melanocytes: first identification and its effects on H2 O2 -induced oxidative damage

BACKGROUND

Oxidative stress plays an important role in initiating the destruction of melanocytes, which could be one possible mechanism of vitiligo. PINK1 is an outer membrane protein of mitochondria, which protects many cells from oxidative stress through regulating mitochondrial function. However, the role of PINK1 and its effects on oxidative damage in melanocytes have not been elucidated.

AIM

To investigate the expression and effects of PINK1 on oxidative stress in human melanocytes.

METHODS

Quantitative reverse transcription-PCR and western blot analysis were used to analyse the expression of PINK1 in PIG1 melanocyte and gene downregulation models. Levels of cell viability, cell apoptosis and intracellular reactive oxygen species (ROS), mitochondrial morphology, mitochondrial membrane potential (MMP) and mitochondrial permeability transition pore (MPTP) opening were measured in PIG1 models transfected with PINK1 small interfering RNA with or without hydrogen peroxide (H₂ O₂ ).

RESULTS

We first observed the expression of PINK1 in human PIG1 melanocytes and found that downregulation of PINK1 made melanocytes more sensitive to oxidative stress induced by H₂ O₂ , with more cell apoptosis and increased intracellular ROS. Meanwhile, downregulation of PINK1 caused morphological changes in mitochondria, decreased the MMP and increased MPTP opening.

CONCLUSIONS

Our study found PINK1 plays an essential role in protecting human melanocytes from oxidative stress.

Isolation of a Bacillus cereus strain HBL-AI and its application for production of Trans-4-hydroxy-l-proline

A new trans-4-hydroxy-l-proline (trans-Hyp) producing Bacillus cereus HBL-AI, was isolated from the air, which was screened just using l-proline as carbon and energy sources. This strain exhibited 73·4% bioconversion rate from initial l-proline (3 g l^-1 ) to trans-Hyp. By sequencing the genome of this bacterium, 6244 coding sequences were obtained. Genome annotation analysis and functional expression were used to identify the proline-4-hydroxylase (BP4H) in HBL-AI. This enzyme belonged to a family of 2-oxoglutarate-related dioxygenases, which required 2-oxoglutarate and O₂ as co-substrates for the reaction. Homologous modelling indicated that the enzyme had two monomers and contained conserved motifs, which included a distorted 'jelly roll' β strand core and the residues (HXDXnH and RXS). The engineering Escherichia coli 3 Δ W3110/pTrc99a-proba-bp4h was constructed using BP4H, which transformed glucose to trans-Hyp in one step with high concentration of 46·2 g l^-1 . This strategy provides a green and efficient method for synthesis of trans-Hyp and thus has a great potential in industrial application.

MicroRNA-449b-5p promotes the progression of osteoporosis by inhibiting osteogenic differentiation of BMSCs via targeting Satb2

OBJECTIVE

We aimed to explore the role of microRNA-449b-5p in osteogenic differentiation of bone marrow mesenchymal stem cells (BMSCs) and its mechanism of action.

MATERIALS AND METHODS

Quantitative Real Time-Polymerase Chain Reaction (qRT-PCR) assay was used to detect the expression levels of microRNA-449b-5p and osteogenic markers including RUNX2, OCN during BMSCs differentiation. The microRNA-449b-5p mimic and microRNA-449b-5p inhibitors were transfected into BMSCs to achieve microRNA-449b-5p overexpression and knockdown, then the expressions of osteogenic markers were detected by qRT-PCR. The ALP activity staining and the alizarin red staining were used to detect the activity of ALP and the mineralization ability of cells after overexpression and knockdown of microRNA-449b-5p. Binding sites for microRNA-449b-5p and Satb2 were predicted by TargetScan, the PicTar and microRNAanda programs, and confirmed by dual-luciferase reporter gene assay. The relationship between microRNA-449b-5p and Satb2 was analyzed by QRT-PCR and Western blot. The microRNA-449b-5p inhibitor and shSATB2 lentivirus were simultaneously transfected in BMSCs, and the expression levels of RUNX2, OCN and ALP were detected by qRT-PCR and ALP activity assays.

RESULTS

microRNA-449b-5p expression gradually decreased during osteogenic differentiation. Overexpression of microRNA-449b-5p inhibited BMSCs differentiation by down-regulating ALP activity, RUNX2, and OCN expression, while the opposite result was observed after knockdown of microRNA-449b-5p. MicroRNA-449b-5p can bind to the 3'UTR end of Satb2, which was involved in the osteogenic differentiation of microRNA-449b-5p-regulated BMSCs, and silencing of Satb2 can abolish the positive effect of the microRNA-449b-5p inhibitor on osteoblasts differentiation.

CONCLUSIONS

microRNA-449b-5p could aggravate osteoporosis by inhibiting osteogenic differentiation of BMSCs through targeting Satb2.

MiR-296-5p inhibits cell invasion and migration of esophageal squamous cell carcinoma by downregulating STAT3 signaling

OBJECTIVE

Many studies have emphasized the function of microRNA-296 (miR-296) that inhibits tumor formation. To some extent, the role of miR-296 in esophageal squamous cell carcinoma (ESCC) remains misleading. Therefore, the current research was designed to investigate the regulatory mechanisms of miR-296 and signal transducer and activator of transcription 3 (STAT3) in ESCC.

PATIENTS AND METHODS

The mRNA expression of miR-296-5p and STAT3 in ESCC tissues or cell lines was measured via quantitative Real Time-Polymerase Chain Reaction (qRT-PCR). The protein level of STAT3 was measured by Western blotting assay. The Luciferase reporter assay was used to verify the binding sites between miR-296-5p and STAT3. The transwell assay was employed to identify cell migration and invasion.

RESULTS

Down-regulation of miR-296-5p was detected in ESCC tissues and cell lines (p<0.01). Additionally, miR-296-5p was found to target STAT3 directly. Functionally, up-regulation of miR-296-5p or down-regulation of STAT3 significantly inhibited cell migration and invasion in ESCC.

CONCLUSIONS

MiR-296-5p inhibited cell invasion and migration in ESCC by downregulating STAT3. The overexpression of miR-296-5p by targeting STAT3 suppressed tumorigenesis of ESCC cells.

Inhibition effect of exosomes-mediated Let-7a on the development and metastasis of triple negative breast cancer by down-regulating the expression of c-Myc

OBJECTIVE

Triple negative breast cancer is typically characterized by high malignancy, easy recurrence and metastasis, and poor prognosis. However, effective treatment for triple negative breast cancer has not yet been identified. Our research explores the underlying mechanisms of exosomes in transporting Let-7a and regulating c-Myc gene and their roles in the development of triple negative breast cancer, and to provide new ideas for targeted therapy of triple negative breast cancer.

PATIENTS AND METHODS

Based on previous studies that focused on the roles of c-Myc and Let-7a in the development of triple negative breast cancer, triple negative breast cancer cell lines have been constructed by c-Myc knockout and overexpression of Let-7a, respectively, to evaluate the effects of c-Myc, and Let-7a, as well as exosomes transmitting Let-7a on the development of triple negative breast cancer.

RESULTS

Let-7a, which is mediated by exosomes, inhibited proliferation, migration, and invasion of MDA-MB-231 cells by binding on the 3'UTR region of the c-Myc gene and silencing of the c-Myc expression.

CONCLUSIONS

Our study revealed the role of c-Myc, Let-7a, and exosomes in the development of triple negative breast cancer, which lay the theoretical foundation for further usage of exosomes to construct tumor killing vectors and for exploring specific targets for triple negative breast cancer.

Long noncoding RNA LUCAT1 promotes cervical cancer cell proliferation and invasion by upregulating MTA1

OBJECTIVE

Recent researches have revealed the role of long noncoding RNAs (lncRNAs) in the development of tumors. In this study, lncRNA LUCAT1 was explored to identify how it affected the progression of cervical cancer.

PATIENTS AND METHODS

Quantitative Real-time polymerase chain reaction (qRT-PCR) was used to detect LUCAT1 expression in both cervical cancer cells and tissue samples. Moreover, the associations between LUCAT1 expression level and patients' overall survival rate were explored, respectively. In addition, cell proliferation assay and transwell assay were conducted. Furthermore, the underlying mechanism was explored via performing qRT-PCR and Western blot assay.

RESULTS

By comparing with the expression level in corresponding ones, the LUCAT1 expression level in cervical cancer samples was significantly higher. Moreover, expression level of LUCAT1 was negatively correlated with patients' overall survival time. In addition, after LUCAT1 was overexpressed, cell proliferation, cell invasion and migration capacities were promoted in vitro. In addition, the mRNA and protein expressions of MTA1 were upregulated after LUCAT1 was overexpressed. Furthermore, it was found that the expression level of MTA1 was positively related to LUCAT1 expression level in cervical cancer tissues.

CONCLUSIONS

We showed that LUCAT1 could enhance proliferation, invasion and migration of cervical cancer cells through upregulating MTA1, which might offer a potential therapeutic choice for patients with cervical cancer.

Dexmedetomidine attenuates myocardial ischemia/reperfusion injury through regulating lactate signaling cascade in mice

OBJECTIVE

The aim of this study was to investigate the role of dexmedetomidine (Dex) in lactate signaling cascade and myocardial ischemia/reperfusion (I/R) injury in mice.

MATERIALS AND METHODS

The left anterior descending of the coronary artery was ligatured for 30 min and then reperfused for 6 h to induce myocardial I/R injury in mice. Heart samples were collected and the levels of lactate, SOD and MDA were measured. Infarct size and myocardium were stained with triphenyltetrazolium chloride and TUNEL, respectively. In addition, the expression levels of MCT1, cytochrome c, cleaved caspase-9 and -3 were detected by Western blot.

RESULTS

The myocardial infarct size, lactate and MDA levels of the I/R group were significantly increased, whereas the SOD activity was decreased. However, Dex significantly reduced the myocardial infarct size, as well as lactate and MDA levels in contrast to the I/R group. Meanwhile, the SOD activity was remarkably increased. The expression levels of MCT1, cytochrome c, cleaved caspase-9 and -3 were significantly increased in the I/R group. In addition, Dex administration further increased the expression of MCT1, whereas decreased the expressions of cytochrome c, cleaved caspase-9 and -3 in contrast to the I/R group.

CONCLUSIONS

Dex elevated the expression of mitochondrial MCT1 and inhibited oxidative stress and the activation of mitochondria-dependent apoptosis in mice. This indicated that Dex attenuated myocardial I/R injury by regulating lactate signaling cascade.