Effect of aberrantly methylated androgen receptor target gene PCDH7 on the development of androgen-independent prostate cancer cells

Siqi Xu,Xiaoyan Wu,Zhihua Tao,Hongsheng Li1,Chenliang Fan,Songjin Chen,Jianwei Guo,Yao Ning,Xuqi Hu 한국유전학회 2020 Genes & Genomics Vol.42 No.3

Background Androgen-independent prostate cancer (AIPC) is an extremely malignant tumor developed from the androgen dependent (ADPC). However, the mechanism of transition process from ADPC to AIPC remains unknown. Objective Here we aimed to identify the androgen receptor (AR) target gene and its roles in AIPC. Methods Target genes of AR were identified by ChIP-seq in AIPC cells. AR target gene PCDH7 was detected by real time PCR and western blot. Methylation of PCDH7 was measured by bisulfite sequencing and bisulfite amplicon sequencing. Cell growth, invasion and apoptosis were measured by CCK-8, transwell and flow cytometry, respectively. Results AR was significantly enriched in the upstream of PCDH7 gene. The expression of PCDH7 was significantly decreased, while the methylation of PCDH7 was increased in the AIPC cells compared to the ADPC cells. DNA methyltransferase inhibitor significantly suppressed the methylation and increased the mRNA and protein level of PCDH7. Moreover, overexpression of DNMT1 remarkably reduced the mRNA and protein level of PCDH7. DNA methyltransferase inhibitor decreased the cell growth and invasion while promote the cell apoptosis in the AIPC cells. AR significantly target PCDH7, whose hypermethylation may repress cell growth and invasion, and promote apoptosis in AIPC. Conclusions This study might provide a novel potential target for the treatment of AIPC.

Determining Osteogenic Differentiation Efficacy of Pluripotent Stem Cells by Telomerase Activity

Siqi Zhang,Yuhua Sun,Yi Sui,Yan Li,Zuyuan Luo,Xiao Xu,Ping Zhou,Shicheng Wei 한국조직공학과 재생의학회 2018 조직공학과 재생의학 Vol.15 No.6

BACKGROUND: Bone tissue engineering based on pluripotent stem cells (PSCs) is a new approach to deal with bone defects. Protocols have been developed to generate osteoblasts from PSCs. However, the low efficiency of this process is still an important issue that needs to be resolved. Many studies have aimed to improve efficiency, but developing accurate methods to determine efficacy is also critical. Studies using pluripotency to estimate efficacy are rare. Telomerase is highly associated with pluripotency. METHODS: We have described a quantitative method to measure telomerase activity, telomeric repeat elongation assay based on quartz crystal microbalance (QCM). To investigate whether this method could be used to determine the efficiency of in vitro osteogenic differentiation based on pluripotency, we measured the pluripotency pattern of cultures through stemness gene expression, proliferation ability and telomerase activity, measured by QCM. RESULTS: We showed that the pluripotency pattern determined by QCM was similar to the patterns of proliferation ability and gene expression, which showed a slight upregulation at the late stages, within the context of the general downregulation tendency during differentiation. Additionally, a comprehensive gene expression pattern covering nearly every stage of differentiation was identified. CONCLUSION: Therefore, this assay may be powerful tools for determining the efficiency of differentiation systems based on pluripotency. In this study, we not only introduce a new method for determining efficiency based on pluripotency, but also provide more information about the characteristics of osteogenic differentiation which help facilitate future development of more efficient protocols.

Identification of drug target candidates of the swine pathogen Actinobacillus pleuropneumoniae by construction of protein–protein interaction network

Siqi Li,Zhipeng Su,Chengjun Zhang,Zhuofei Xu,Xiaoping Chang,Jiawen Zhu,Ran Xiao,Lu Li,Rui Zhou 한국유전학회 2018 Genes & Genomics Vol.40 No.8

Porcine pleuropneumonia caused by Actinobacillus pleuropneumoniae has led to severe economic losses in the pig industry worldwide. A. pleuropneumoniae displays various levels of antimicrobial resistance, leading to the dire need to identify new drug targets. Protein–protein interaction (PPI) network can aid the identification of drug targets by discovering essential proteins during the life of bacteria. The aim of this study is to identify drug target candidates of A. pleuropneumoniae from essential proteins in PPI network. The homologous protein mapping method (HPM) was utilized to construct A. pleuropneumoniae PPI network. Afterwards, the subnetwork centered with H-NS was selected to verify the PPI network using bacterial two-hybrid assays. Drug target candidates were identified from the hub proteins by analyzing the topology of the network using interaction degree and homologous comparison with the pig proteome. An A. pleuropneumoniae PPI network containing 2737 non-redundant interaction pairs among 533 proteins was constructed. These proteins were distributed in 21 COG functional categories and 28 KEGG metabolic pathways. The A. pleuropneumoniae PPI network was scale free and the similar topological tendencies were found when compared with other bacteria PPI network. Furthermore, 56.3% of the H-NS subnetwork interactions were validated. 57 highly connected proteins (hub proteins) were identified from the A. pleuropneumoniae PPI network. Finally, 9 potential drug targets were identified from the hub proteins, with no homologs in swine. This study provides drug target candidates, which are promising for further investigations to explore lead compounds against A. pleuropneumoniae.

Batch Fabrication and Characterization of ZnO/PLGA/PCL Nanofiber Membranes for Antibacterial Materials

Siqi Li,Jing Yin,Lan Xu 한국섬유공학회 2022 Fibers and polymers Vol.23 No.5

As biomaterials with excellent biocompatibility, biodegradation and low toxicity, poly(ε-caprolactone) (PCL) andpoly(lactic-co-glycolic acid) (PLGA) are extensively applied as wound dressing and surgical suture in biomedical field. Inthis paper, an oblique section free surface electrospinning (OSFSE) apparatus was utilized to prepare high-quality and highoutputZnO/PLGA/PCL nanofiber membranes (NFMs) for antibacterial materials, which could significantly increase theproduction of ZnO/PLGA/PCL NFMs from 0.01-0.1 g/h of traditional electrospinning to 30.84 g/h of OSFSE. The influencesof the weight proportion of PLGA and PCL on the viscosity and conductivity of electrospinning solutions along with theyield, morphology and wettability of PLGA/PCL NFMs were researched, and the optimum weight ratio of 6:4 wasdetermined. Then the effects of ZnO contents on the electrospinning solution properties as well as the yield, morphology,structure, wettability, mechanical property and antibacterial performance of ZnO/PLGA/PCL NFMs with the optimal ratio ofPLGA and PCL were studied. The results illustrated that additive nano-ZnO could improve markedly the antibacterial effectof NFMs, and the NFMs with 3 wt% nano-ZnO had excellent antibacterial effect on Escherichia coli (95.3 %) andStaphylococcus aureus (95.7 %).

Comparison of Endocrine Therapies in Hormone Receptor-Positive and Human Epidermal Growth Factor Receptor 2-Negative Locally Advanced or Metastatic Breast Cancer: A Network Meta-Analysis

Siqi Liu,Xin Sun,Xiaohui Xu,Fangcai Lin 한국유방암학회 2020 Journal of breast cancer Vol.23 No.5

We aimed to explore what kind of endocrine treatments are optimal for hormone receptor-positive and human epidermal growth factor receptor 2-negative locally advanced or metastatic breast cancer in some specific clinical situations. We searched randomized controlled trials in Embase, Medline, the Cochrane library, and PubMed from inception to April 1, 2020 and performed a network meta-analysis based on a Bayesian fixed-effects model. Progression-free survival (PFS) with hazard ratios and corresponding 95% confidence interval was defined as the primary endpoint, while overall survival (OS), objective response rate (ORR), clinical benefit rate and serious adverse events were used as secondary endpoints. A total of 35 studies involving 12,285 patients and 24 treatment options were included. In general, most co-treatment options prolonged PFS compared to single-agent therapy, of which aromatase inhibitor (AI) plus everolimus and fulvestrant plus palbociclib were probably the most effective agents, and the latter had the best safety record. However, despite the superior efficacy of fulvestrant plus capecitabine for PFS and OS, palpable toxic effects have been demonstrated for this treatment, so its application must be scrupulously considered. The results of subgroup analysis indicated that fulvestrant combined with palbociclib improved prognosis for phosphatidylinositol 3-kinase (PI3K)-mutated patients, PI3K-unmutated patients, patients with endocrine therapy resistance, and visceral metastatic patients, while no obvious improvement was detected in OS. Moreover, the efficacy of fulvestrant plus cyclin-dependent kinase 4/6 (CDK4/6) inhibitors was slightly better than that of AI plus CDK4/6 inhibitors, while AI plus everolimus was more efficacious than fulvestrant combined with everolimus in terms of PFS, OS, and ORR. In conclusion, our results provide moderate evidence that fulvestrant plus palbociclib and AI plus everolimus were the most effective treatments, while the efficacy and safety of fulvestrant plus palbociclib was obviously superior in some specific clinical situations.

Non-square colour image scrambling based on two-dimensional Sine-Logistic and Henon map

( Siqi Zhou ),( Feng Xu ),( Ping Ping ),( Zaipeng Xie ),( Xin Lyu ) 한국인터넷정보학회 2017 KSII Transactions on Internet and Information Syst Vol.11 No.12

Image scrambling is an important technology in information hiding, where the Arnold transformation is widely used. Several researchers have proposed the application of Henon map in square image scrambling, and certain improved technologies require scrambling many times to achieve a good effect without resisting chosen-plaintext attack although it can be directly applied to non-square images. This paper presents a non-square image scrambling algorithm, which can resist chosen-plaintext attack based on a chaotic two-dimensional Sine Logistic modulation map and Henon map (2D-SLHM). Theoretical analysis and experimental results show that the proposed algorithm has advantages in terms of key space, efficiency, scrambling degree, ability of anti-attack and robustness to noise interference.

The effects of aging for improving wastewater sludge electro-dewatering performances

Hang Lv,Daoguang Liu,Siqi Xing,Dandan Wu,Fang Wang,Jiakuan Yang,Xu Wu,Wenbiao Zhang,Xiaohu Da 한국공업화학회 2019 Journal of Industrial and Engineering Chemistry Vol.80 No.-

The effects of sludge aging on improving sludge electro-dewatering (SED) performance were studied,with the sludge properties variation during aging process investigated. Sludge electro-dewateringperformances were explored by constant voltage method (25 V) on various samples. The organic matterin the extracellular polymeric substances (EPS) was gradually consumed and decomposed during sludgeaging process. Under identical electro-dewatering conditions, dewaterability and time-space yield ofaged sludge achieved 49.33% solid content and 223.46 kg m 2 h 1 respectively. Such results indicate thebeneficial effects of sludge aging process in terms of SED performances, which needs further explorationinto fundamental mechanisms.

Batch Preparation and Characterization of Anthocyanin/CS/PEO Nanofiber Membranes for Food Packages

Adnan Ahmed,Meng Zhang,Siqi Li,Lan Xu 한국섬유공학회 2023 Fibers and polymers Vol.24 No.9

Chitosan (CS), as a biocompatible and biodegradable nature polymer, has excellent antibacterial property. Poly(ethylene oxide) (PEO), as a biomaterial with thermal stability, biocompatibility and biodegradability, has good spinnability. Anthocyanin, as a natural colorant agent with different molecular structures under different pH values, has good antibacterial and antioxidant properties and can be applied as a pH indicator. Electrospun nanofiber membranes (NFMs) show great application prospects in food packaging due to their unique structural and functional advantages. In this work, anthocyanin/CS/PEO nanofiber membranes (NFMs) for food packaging were batch prepared by the spherical section free surface electrospinning (SSFSE), and their yield reached 5.8 ± 0.4 g/h. The morphology, structure and properties of CS-based NFMs were explored, which showed that they were hydrophilic and had excellent antibacterial activity against Escherichia coli (E. coli) and Staphylococcus aureus (S. aureus). Among them, anthocyanin/CS/PEO NFMs exhibited better mechanical properties and high antioxidant activity. Furthermore, the color changes of anthocyanin/CS/PEO NFMs at different pH values were investigated, illustrating that they could be used as a visual monitoring food packaging, and their application effects in beef storage were studied.

Negative sequence control for DC voltage balancing in three‑phase cascaded H‑bridge rectifiers considering DC‑port failures

Xinyu Zhu,Xiao Liang,Kaiyue Gong,Xu Peng,Jun Cai,Xiaohan Liu,Chao Zhou,Siqi An,Chao Wu,Pengcheng Han 전력전자학회 2022 JOURNAL OF POWER ELECTRONICS Vol.22 No.12

As a vital component of power electronic transformers (PET), the reliability of a cascaded H-bridge rectifier (CHBR) is essential. Therefore, in this paper, a DC-port voltage balance strategy considering DC-port failure is researched to ensure the stable operation of a CHBR. However, if the DC-port voltage balance strategy is adopted to realize the single-phase balance of a CHBR, the three-phase currents become unbalanced. This paper uses a negative sequence control (NSC) strategy that is conducive to balancing DC-port voltage to achieve three-phase current balance. For the DC-port voltage balance, the matrix generation modulation (MGM) algorithm is proposed. In addition, the DC-port voltage balance boundary is analyzed to determine the range of the DC-port voltage balance in the CHBR. A 3-module cascading topology is adopted to demonstrate the MGM algorithm and the NSC strategy. Through experiments, results show the correctness and feasibility of the proposed strategy.

Cycle-Consistent Generative Adversarial Network: Effect on Radiation Dose Reduction and Image Quality Improvement in Ultralow-Dose CT for Evaluation of Pulmonary Tuberculosis

Yan Chenggong,Lin Jie,Li Haixia,Xu Jun,Zhang Tianjing,Chen Hao,Woodruff Henry C.,Wu Guangyao,Zhang Siqi,Xu Yikai,Lambin Philippe 대한영상의학회 2021 Korean Journal of Radiology Vol.22 No.6

Objective: To investigate the image quality of ultralow-dose CT (ULDCT) of the chest reconstructed using a cycle-consistent generative adversarial network (CycleGAN)-based deep learning method in the evaluation of pulmonary tuberculosis. Materials and Methods: Between June 2019 and November 2019, 103 patients (mean age, 40.8 ± 13.6 years; 61 men and 42 women) with pulmonary tuberculosis were prospectively enrolled to undergo standard-dose CT (120 kVp with automated exposure control), followed immediately by ULDCT (80 kVp and 10 mAs). The images of the two successive scans were used to train the CycleGAN framework for image-to-image translation. The denoising efficacy of the CycleGAN algorithm was compared with that of hybrid and model-based iterative reconstruction. Repeated-measures analysis of variance and Wilcoxon signedrank test were performed to compare the objective measurements and the subjective image quality scores, respectively. Results: With the optimized CycleGAN denoising model, using the ULDCT images as input, the peak signal-to-noise ratio and structural similarity index improved by 2.0 dB and 0.21, respectively. The CycleGAN-generated denoised ULDCT images typically provided satisfactory image quality for optimal visibility of anatomic structures and pathological findings, with a lower level of image noise (mean ± standard deviation [SD], 19.5 ± 3.0 Hounsfield unit [HU]) than that of the hybrid (66.3 ± 10.5 HU, p < 0.001) and a similar noise level to model-based iterative reconstruction (19.6 ± 2.6 HU, p > 0.908). The CycleGAN-generated images showed the highest contrast-to-noise ratios for the pulmonary lesions, followed by the model-based and hybrid iterative reconstruction. The mean effective radiation dose of ULDCT was 0.12 mSv with a mean 93.9% reduction compared to standard-dose CT. Conclusion: The optimized CycleGAN technique may allow the synthesis of diagnostically acceptable images from ULDCT of the chest for the evaluation of pulmonary tuberculosis.