BACKGROUND:Methylmalonic acid (MMA), a sensitive biomarker of mitochondrial dysfunction, has been associated with various chronic diseases, but its role in chronic obstructive pulmonary disease (COPD) remains unclear. This study aimed to investigate the association between serum MMA and COPD and the statistical mediation of systemic inflammation. METHODS:Based on NHANES 2013-2014 data, 5139 adults were included. Multivariable logistic regression was used to analyze the association between MMA and COPD. Restricted cubic spline (RCS) assessed non-linear relationships, and statistical mediation analysis examined the mediating effects of inflammatory indices. Subgroup and sensitivity analysis were used to verify the stability of the results. RESULTS:A significant inverted L-shaped non-linear association between MMA and COPD was identified (P for non-linearity = 0.038), with an inflection point at 135 nmol/L (ln-MMA = 4.91). Below this threshold, each one-unit increase in ln-MMA was associated with a 4.59-fold increased odds ratio of COPD (OR = 4.59, 95%CI: 1.54-13.65), whereas the association disappeared above the threshold. Systemic inflammation partially statistically mediated this association (3.7%-10.2%), with monocyte-to-lymphocyte ratio (MLR) and systemic inflammatory response index (SIRI) showing the strongest mediating effects. The results of subgroup analysis and sensitivity analysis were stable. CONCLUSIONS:MMA was nonlinearly associated with COPD prevalence, systemic inflammation statistically accounts for part of this association. MMA may serve as a candidate biomarker for COPD prevalence in future prospective studies, although temporal ordering cannot be established from this cross-sectional analysis.

Oxidative stress is a central driver of environmental stress responses and disease pathogenesis. Increasing evidence indicates that RNA epigenetic regulation, particularly N6-methyladenosine (m6A) modification, represents a critical interface linking redox imbalance to cellular dysfunction. Arsenic, a prototypical redox-active toxicant, provides a robust model for understanding how environmental oxidative stress disrupts m6A-mediated post-transcriptional control. Recent studies demonstrate that arsenic-induced redox perturbation reshapes the expression and activity of m6A writers (METTL3/METTL14), erasers (FTO/ALKBH5), and readers (YTHDF/YTHDC families), leading to widespread alterations in mRNA stability, translation, and metabolic reprogramming. Mechanistic findings from cellular and animal models implicate m6A-dependent pathways in modulating oxidative stress responses, mitochondrial function, inflammation, and senescence—biological processes fundamental to redox biology. These insights reveal that m6A is not merely a downstream marker of stress, but an active mediator of adaptive and maladaptive responses to redox disruption. Despite significant progress, population-level evidence and high-resolution mapping of RNA modifications under oxidative conditions remain limited. Future work integrating advanced epitranscriptomic profiling, multi-omics approaches, and exploration of additional RNA modifications (m7G, m1A, m5C) will be essential for defining how redox-sensitive RNA regulation shapes disease risk. Collectively, this review highlights m6A modification as a dynamic regulatory node connecting environmental redox stress to gene expression control, providing new mechanistic insight and potential targets for intervention in redox-related diseases.

The contractile force exerted by hepatic stellate cells (HSCs) plays a critical role in both physiological and pathological processes in the liver. Endothelin-1 (ET-1), a key inducer of HSC activation and contraction, can rapidly trigger cellular contractions within minutes, placing demands on the spatiotemporal resolution of detection tools. However, existing methods for measuring HSC mechanics often fail to simultaneously achieve precise mechanical quantification, high spatiotemporal resolution, and high-throughput analysis. To address these limitations, we employed a photonic crystal cellular force microscopy system that utilizes structural color changes of a photonic crystal substrate to sensitively detect minute cellular deformations and nanoscale vertical forces. This system integrates single-cell precision, high spatiotemporal resolution, and high-throughput capabilities. Using this platform, we successfully visualized and quantified the subcellular mechanical distribution within minutes during the contraction and migration of individual HSCs. Our findings demonstrate that photonic crystal cellular force microscopy provides a real-time, intuitive, and powerful approach for investigating HSC biomechanics, offering potential mechanical insights into liver disease mechanisms and drug screening.

Organoids have emerged as one of the most predictive preclinical models in medical research due to their ability to closely retain the genetic and phenotypic characteristics of original tissues. Nevertheless, the application in the systematic evaluation of innovative medical devices (especially biodegradable metals) remains largely unexplored, whereas conventional analytical approaches have significant limitations in data throughput, objectivity, and reproducibility. Recent advances in deep learning-based artificial intelligence (AI) image analysis offer powerful quantitative tools to overcome this bottleneck. In this study, we established a high-throughput quantitative in vitro evaluation platform for the dynamic assessment of biodegradable metal ions by integrating patient-derived colorectal cancer organoids with an OrganoSeg-based deep learning AI image analysis system. Systematic assessments revealed that Mg2+ and Zn2+ had significant concentration-dependent effects on organoid growth, and the organoid model exhibited sensitivity profiles distinct from conventional cell lines. RNA-seq analysis further revealed that high concentrations of Mg2+ induced cell cycle arrest by activating the p53/CDKN1C signaling axis. In contrast, high concentrations of Zn2+ disrupted intracellular zinc homeostasis by regulating metallothionein family members and the zinc transporter SLC39A10, triggering a robust inflammatory response and ultimately leading to apoptosis. This work not only confirms the considerable potential of integrating organoids with AI technology in the evaluation of medical devices, but also reveals the differential mechanism of action of bioactive metal ions Mg2+ and Zn2+ in a model closer to the human environment. This study establishes a reliable and generalizable paradigm for high-throughput and high-content biomedical research.

Recently, significant advancements have been witnessed in variousin vitrotreatment evaluation models, especially organoids and organs-on-chips.In vitroculture of cancer cells and drug screening are key technical components in functional oncology precision medicine. However, most studies primarily focus on constructing models using established cell lines, with limited integration with clinical diagnosis or patient treatment. This review provides a brief overview of precision medicine models, followed by discussions on the broad spectrum of applications involving two-dimensional tumor cell culture, patient-derived tumor xenograft models, tumor organoids, and tumors-on-chips. It highlights the success rate of patient-derived tumor organoids construction and their application in clinical trials. Recent advancements in tumors-on-chips and organoids-on-chips are elaborated on, alongside with integration of other new generation technologies. Additionally, this review summarizes the advantages and constraints associated with tumor organoids and tumors-on-chips, underscoring their crucial role in the advancement of personalized medicine.

Background: Microplastics and nanoplastics are emerging foodborne contaminants that pose significant and underexplored threats to human health, particularly through their interactions with the gut-brain axis. Scope and approach: Here we provide an in-depth exploration of the mechanistic pathways underlying the toxic effects of micro-and nanoplastics, with a focus on their impact on gut microbiota homeostasis, intestinal barrier integrity, oxidative stress, inflammation, and immune modulation. Drawing on insights from multiple model organisms, including Caenorhabditis elegans, Danio rerio, Drosophila, and rodents, we synthesize current knowledge regarding the diverse ways in which plastic particles disrupt intestinal function and induce systemic toxicity, providing valuable insights into the effects and underlying mechanisms of intestinal toxicity and gut-based external organ impairment. Plastic particles can cause mechanical damage and dysfunction in the intestinal tract and even neuronal damage by altering the intestinal flora. Key findings and conclusions: One of the key innovations of this review is its exploration of the role of micro-and nanoplastics as vectors for dietary pollutants such as heavy metals, organic contaminants, and antibiotics, emphasizing the compounded risks of combined exposures. By integrating findings from various models, we highlight how plastic particles' mechanical, chemical, and physical properties contribute to their toxicity and the challenges these pose to the scientific community. Importantly, we identify significant gaps in understanding, such as the long-term effects of chronic exposure to different plastic types and their potential for cumulative toxicity over time. This review also underscores the urgent need for standardized methodologies to detect and quantify plastic particles in biological systems, and calls for innovative strategies to mitigate their harmful effects through both dietary interventions and pharmaceutical approaches.

Venetoclax, an inhibitor that selectively targets B cell lymphoma-2 (BCL-2) that has been approved for treating adult acute myeloid leukemia (AML) in combination with hypomethylating agents. However, its short duration of response and emergence of resistance are significant issues. In this study, we found that the sensitivity of AML cells to venetoclax was considerably enhanced by ML385, an inhibitor of the ferroptosis factor nuclear transcription factor erythroid 2-related factor 2 (NRF2). Using AML samples, we verified that NRF2 and its target gene ferritin heavy chain 1 (FTH1) were highly expressed in patients with AML and correlated with poor prognosis. Downregulation of NRF2 could inhibit FTH1 expression and significantly enhance the venetoclax-induced labile iron pool and lipid peroxidation. By contrast, NRF2 overexpression or administration of the reactive oxygen species inhibitor N-acetylcysteine and vitamin E could effectively suppress the anti-AML effects of ML385+venetoclax. Furthermore, the ferroptosis inducer erastin increased the anti-AML effects of venetoclax. Our study demonstrated that NRF2 inhibition could enhance the AML cell death induced by venetoclax via the ferroptosis pathway. Thus, the combination of ML385 with venetoclax may offer a favorable strategy for AML treatment.

Background B-cell acute lymphoblastic leukemia (B-ALL) is one of the common hematological malignancies, and dysfunction of the IKAROS leukemia suppressor is a hallmark of high-risk B-ALL with high relapse rates and poor outcome (N Engl J Med, 2009, 360:470; Blood 2015, 126:1813). We reported that the Casein kinase II inhibitor CX4945 showed therapeutic efficacy in high-risk B-ALL by reducing the phosphorylation of IKAROS and restoring its function (Blood 2015, 126:1813; 2020, 136:1520; Leukemia 2021, 35:1267). However, CX4945 has relatively poor bioavailability and a rapid degradation rate (Arch Pharm Res 2013, 36:840) and nanoparticle encapsulation may significantly improve the therapeutic efficacy of the drug by increasing its bioavailability and stability. On the other hand, the homing of ALL cells to the bone marrow relies on the regulation of the C-X-C chemokine receptor 4 (CXCR4), which specifically binds to CXCL12 ligand secreted by bone marrow stromal cells (Blood 2015, 126:1297). Thus, the biomimetic nanodrugs coated with stromal cell membranes can facilitate the drugs to leukemia niches in the bone marrow. This study aims to develop a biomimetic Nanodrug Delivery System to improve biocompatibility and enhance the specific targeting of the CX4945 on high-risk B-ALL in vivo. Methods The morphology, elemental composition, size, surface charge, and polymer dispersity index of the biomimetic nanodrug CX4945@PLGA-PEG@CM NPs were analyzed by transmission electron microscopy, scanning electron microscopy, and dynamic light scattering to characterize the nanoparticles (Bioact Mater 2022, 18:526 ). The encapsulation efficiency, drug loading, and drug release behavior of nanoparticles were tested by UV-visible absorption spectroscopy (Drug Deliv 2021, 28:2480). The blood compatibility of CX4945@PLGA-PEG@CM NPs was determined by a microplate reader. Cell Counting Kit-8 (CCK-8) to assess cell viability. Results The results showed that all nanoparticles were spherical under transmission electron microscopy, and there was a clear cell membrane shell on the surface of CX4945@PLGA-PEG@CM NPs. The elemental analysis of scanning electron microscopy contained Cl, P, and S elements, confirming the successful preparation of CX4945@PLGA-PEG@CM NPs. The encapsulation rate was about 74% and the drug loading capacity was about 3.5%. Furthermore, CX4945@PLGA-PEG@CM NPs could prolong the drug circulation time. The stability of the drug delivery system was related to the safety and effectiveness of the drug delivery process. When CX4945@ PLGA-PEG@ CM NPs were immersed in distilled water for 7 days or incubated under physiological conditions for 72 hours, the biomimetic nanomedicine exhibited significant stability. The safety of nanomedicines determines whether they can be widely used in the clinic. Both CX4945@PLGA-PEG NPs or CX4945@PLGA-PEG@CM NPs showed no obvious hemolysis and good biocompatibility. We explore the cytotoxicity of the nanodrugs on the NALM6 B-ALL cells with high expression of CXCR4. Results showed both CX4945@PLGA-PEG@CM Nps and CX4945@PLGA-PEG NPs showed dose-dependent cytotoxicity on the cells, and their effect is significantly enhanced compared to CX4945 only control. CX4945@PLGA-PEG@CM NPs showed significantly higher cytotoxicity compared with CX4945@PLGA-PEG NPs and free CX4945 drug in the cells. The strongness of the cytotoxic effect is in order of CX4945@ PLGA-PEG@ CM > CX4945@PLGA-PEG > free CX4945 drug. Conclusions We successfully generated two new nanodrugs,CX4945@PLGA-PEG@CM NPs and CX4945@PLGA-PEG NPs with strong cytotoxicity effects on B-ALL cells. CX4945@PLGA-PEG@CM NPs is a biomimetic nanodrug with a core-shell structure, which has high stability and biocompatibility to delay the release of CX4945 drug and improve the bioavailability of the drug. Our study not only provides the evidence to get a better CK2 inhibitor for the therapy of B-ALL but also provides a theoretical basis using a biomimetic nano-delivery system to optimize drug treatment and even a new possibility for hematological drug research.

B-cell lymphoma/leukaemia 11B (BCL11B) is an essential transcriptional regulator of T cells and is engaged in regulating vital biological processes including T-cell development, proliferation, differentiation and survival.1, 2 Previous studies have shown that BCL11B exhibits abnormally high expression levels in cases of T-cell acute lymphoblastic leukaemia (T-ALL) and that its deletion can significantly induce apoptosis of T-ALL cells.3, 4 However, the molecular mechanism underlying this process remains unclear. Here, we identified X-ray repair cross complementing protein 5 (XRCC5) as a binding protein of BCL11B and XRCC5 may regulate BCL11B expression in both transcriptional and protein level to inhibit the apoptosis of T-ALL. In addition, we also found a new target gene of BCL11B namely Chromosome 11 Open Reading Frame 21 (C11ORF21), which also has an effect on the pathogenesis of T-ALL. Our study indicates that the XRCC5/BCL11B/C11ORF21 signalling pathway is a potential target in the treatment of T-ALL. In this study, immunoprecipitation and mass spectrometry (MS) were first used to screen for binding proteins of BCL11B. In three T-ALL cell lines, CCRF, JURKAT and MOLT4, proteins binding BCL11B were identified through immunoprecipitation followed by MS (Figure 1A). Interestingly, XRCC5 was repeatedly identified in the MS data of all the three T-ALL cell lines, and was confirmed in the CCRF and 293T cells (Figure 1B,C). This result demonstrated that XRCC5 has an interaction with BCL11B. XRCC5 was initially recognised for its role in mending double-stranded DNA breaks; henceforth, it was deemed to promote therapeutic resistance against cancerous cells, induced by DNA-damaging agents.5-7 We then found XRCC5 binds to the X1 region of BCL11B, which contains Leucine-zipper domain that is responsible for sequence specific DNA binding (Figure 1D), indicating XRCC5 may function as a co-transcription factor with BCL11B to modulate the downstream gene expression. In addition, we also found that XRCC5 was significantly up-regulated in primary T-ALL cells and positively correlated with BCL11B expression (Figure 2A–D). Moreover, both BCL11B and XRCC5 expressions were inhibited in CCRF and JURKAT treated with Doxorubicin or Vincristine (Figure 2E,F), suggesting that targeting the XRCC5/BCL11B signalling pathway holds promise for the diagnosis and therapeutic intervention of T-ALL. These results suggest that expression of XRCC5 correlated with expression of BCL11B and play important roles in regulating the survival of T-ALL cells. We have previously shown that inhibition of BCL11B expression could significantly induce apoptosis in T-ALL cells8; thus, we next explored the function of XRCC5 in the survival of T-ALL cells. XRCC5 was shown to be effectively knocked down by siRNA (Figure 3A,B). As expected, the knockdown of XRCC5 promotes the apoptosis of CCRF and JURKAT cells (Figure 3C). It is noteworthy that the combination of XRCC5 and BCL11B siRNA treatment significantly enhanced CCRF and JURKAT cell apoptosis compared to single-gene siRNA (Figure 3D). In addition, down-regulation of XRCC5 can inhibit the expression of BCL11B. In contrast, inhibition of BCL11B has no effect on XRCC5 (Figure S1), suggesting that XRCC5 is an upstream regulator of BCL11B. Taken together, these data confirmed the involvement of XRCC5 and BCL11B in T-ALL survival. To delve deeper into the mechanism of XRCC5/BCL11B regulating T-ALL cell survival, we took the intersection of the differential genes and the genes strongly related to BCL11B in the GSE13159 dataset, and differential genes in the CCRF-siBCL11B dataset, and then C11ORF21, the downstream gene of BCL11B was screened (Figure 4A,B). Subsequently, we analysed the expression of C11ORF21 in 40 samples of T-ALL patients from our clinical centre and the data from GEO database (GSE13159). In contrast to XRCC5 and BCL11B, C11ORF21 was significantly down-regulated in T-ALL, and there was an inverse correlation between the expression of C11ORF21 and that of BCL11B (Figure 4C–F). In addition, C11ORF21 expression was activated when T-ALL was treated with Doxorubicin or Vincristine (Figure 4G,H). These results suggest that BCL11B may directly inhibit the expression of C11ORF21 which may benefit T-ALL cell survival. Furthermore, we confirmed that down-regulating the expression of BCL11B in JURKAT cells activated the expression of C11ORF21 (Figure 4I,J). In order to determine whether BCL11B can directly transcriptionally regulate the expression of C11ORF21, we found multiple BCL11B binding sites in the C11ORF21 gene through CUT-tag combined sequencing technology (Figure 4K). Taken together, these findings suggest that C11ORF21 serves as a novel BCL11B target gene involved in the regulation of T-ALL cell survival. C11ORF21 is a novel gene situated within the human chromosome 11p15.5 locus, with potential implications in Beckwith–Wiedemann syndrome and cancers.9 By northern blotting, this gene was found to exhibit exclusive expression solely in the human heart. Demonstration of C11ORF21–EGFP fusion protein proved that the encoding of a 132-amino acid protein by C11ORF21, predominantly situated within the cytoplasm.9 Until now, the biological function of C11ORF21 has not been elucidated. Recently, Matsumoto et al. showed that C11ORF21 is a novel target gene of RUNX1, while the fusion protein RUNX1–ETO inhibited C11ORF21 expression in AML1–ETO leukaemia.10 These findings suggest that RUNX1 was recruited as co-factor to around all classes of target genes of BCL11B in the T-cell fate commitment.1 Thus, BCL11B and RUNX1 may bind together to repress the expression of C11ORF21 in T-ALL, therefore, targeting C11ORF21 might be a latent way to treat T-ALL. However, the co-regulation of RUNX1 and BCL11B remained to be explore in the future. Taken together, using immunoprecipitation, real-time quantitative polymerase chain reaction, siRNA and other methods, our work suggests that XRCC5 can bind to BCL11B, subsequently suppressing C11ORF21, and facilitating the survival of T-ALL cells (Figure S2). However, there are limitations in this study, which are needed to further investigation. First, the molecular mechanism underlying the regulation of BCL11B by XRCC5 is not yet fully elucidated. Second, although XRCC5 and C11ORF21 have been found to be dysregulation in T-ALL, their roles in vivo, along with their involvement in T-ALL development and treatment, remain to be extensively investigated. In conclusion, the XRCC5/BCL11B/C11ORF21 axis has a crucial role in the development of T-ALL and may serve as a promising candidate for therapeutic interventions against T-ALL. Xibao Yu, Yuchen Li and Pengyue Yang performed the experiments, wrote the paper and analysed the data. Yan Wang, Xuan Liu and Letong Cai helped analyse the data. Jing Lai, Yue Zhang and Xianfeng Zha diagnosed and treated the patients and collected clinical samples. Grzegorz Krzysztof Przybylski helped to edit the results and revise the manuscript. Yangqiu Li, Ling Xu and Xibao Yu designed the study and wrote the manuscript. All the authors read and approved the final manuscript. We acknowledge the GEO (https://www.ncbi.nlm.nih.gov/geo/) (GSE13159) for providing the datasets. This work was supported in part by the Intergovernmental International Cooperation on Scientific and Technological Innovation Project of Chinese Ministry of Science and Technology (no. 2017YFE0131600), the National Natural Science Foundation of China (nos. 82200167 and 82000108), the Guangdong Basic and Applied Basic Research Foundation (no. 2021A1515110140), the National Innovation and Entrepreneurship Training Program for Undergraduate (no. 202310559052) and the National Centre for Research and Development, Poland (no. WPC/BCL/2019). The authors declare they have no conflicts of interest. The study (no. 20220223) was approved by the Ethics Committee of the Affiliated Hospitals of Jinan University. Please note: The publisher is not responsible for the content or functionality of any supporting information supplied by the authors. Any queries (other than missing content) should be directed to the corresponding author for the article.

OBJECTIVE:To carry out optical genome mapping (OGM) for a Chinese pedigree with a rare paracentric reverse insertion of chromosome 17.METHODS:A high-risk pregnant woman identified at the Prenatal Diagnosis Center of Hangzhou Women's Hospital in October 2021 and her family members were selected as the study subjects. Chromosome G banding analysis, fluorescence in situ hybridization (FISH), single nucleotide polymorphism array (SNP array) and OGM were applied to verify the balanced structural abnormality of chromosome 17 in the pedigree.RESULTS:Chromosomal karyotyping analysis and SNP array assay have identified a duplication of 17q23q25 in the fetus. Karyotyping analysis of the pregnant woman showed that the structure of chromosome 17 was abnormal, whilst SNP array has detected no abnormality. OGM revealed that the woman has carried a paracentric reverse insertion, which was confirmed by FISH. The karyotype of her husband was normal.CONCLUSION:The duplication of 17q23q25 in the fetus has derived from a paracentric reverse insertion of chromosome 17 in its mother. OGM has the advantage for delineating balanced chromosome structural abnormalities.

The tissue-engineered blood vessel (TEBV) has been developed and used in cardiovascular disease modeling, preclinical drug screening, and for replacement of native diseased arteries. Increasing attention has been paid to biomechanical cues in TEBV and other tissue-engineered organs to better recapitulate the functional properties of the native organs. Currently, computational fluid dynamics models were employed to reveal the hydrodynamics in TEBV-on-a-chip. However, the biomechanical wall stress/strain conditions in the TEBV wall have never been investigated. In this paper, a straight cylindrical TEBV was placed into a polydimethylsiloxane-made microfluidic device to construct the TEBV-on-a-chip. The chip was then perfused with cell culture media flow driven by a peristaltic pump. A three-dimensional fluid–structure interaction (FSI) model was generated to simulate the biomechanical conditions in TEBV and mimic both the dynamic TEBV movement and pulsatile fluid flow. The material stiffness of the TEBV wall was determined by uniaxial tensile testing, while the viscosity of cell culture media was measured using a rheometer. Comparison analysis between the perfusion experiment and FSI model results showed that the average relative error in diameter expansion of TEBV from both approaches was 10.0% in one period. For fluid flow, the average flow velocity over a period was 2.52 cm/s from the FSI model, 10.5% higher than the average velocity of the observed cell clusters (2.28 mm/s) in the experiment. These results demonstrated the facility to apply the FSI modeling approach in TEBV to obtain more comprehensive biomechanical results for investigating mechanical mechanisms of cardiovascular disease development.

In recent years, Android application privacy leaking issues frequently occur, with the results that privacy leakage detection becomes a critical role in app market security review, and numerous mobile apps have been removed from the app stores as a consequence. At the same time, manual review is still considered as a main method for market security audit, but it would cause low efficiency and high false positive when faced with thousands of auditing tasks. To overcome the above problems, this paper implements a large volume, automated detection of privacy leaks in Android applications via machine learning algorithms. In order to achieve a comprehensive and in-depth analysis of application behavior features, firstly, 2346 benign software from app market and 1912 malware identified by a national regulatory authority as leaking privacy in the past two years were selected and studied using a hybrid static-dynamic analysis. Then by developing novel sensitivity criteria, we opt privacy-sensitive key permissions and API calls that are highly relevant to privacy leakage behavior. Moreover, in order to improve the practicability of our system, this thesis systematically optimize the application exerciser on the Android emulator, and achieve average per-app analysis time with less than 2 minutes. Finally, the results of the comparison experiments reveal that the stacking ensemble learning algorithm displayed the best classification performance and achieved 97.81% in accuracy of privacy leakage behavior detection.

Repair of spinal cord injury (SCI) depends on microenvironment improvement and the reconnection between injured axons and regenerated neurons. Here, we fabricate a GelMA-MXene hydrogel nerve conduit with electrical conductivity and internal-facing longitudinal grooves and explore its function in SCI repair. It is found that the resultant grooved GelMA-MXene hydrogel could effectively promote the neural stem cells (NSCs) adhesion, directed proliferation and differentiation in vitro. Additionally, when the GelMA-MXene conduit loaded with NSCs (GMN) is implanted into the injured spinal cord site, effective repair capability for the complete transection of SCI was demonstrated. The GMN group shows remarkable nerve recovery and significantly higher BBB scores in comparison to the other groups. Therefore, GMN with the microgroove structure and loaded with NSCs is a promising strategy in treating SCI.

A major factor for developing new tumor models is to recreate a proper three-dimensional environment for 3D tumors culture. In this 3D microenvironment, extracellular matrices play important roles in regulation of hallmark features of cancer through biochemical and mechanical signals. The fabrication of a mechanical and biophysical controllable hydrogel, while sharing similarities with Matrigel in cancer invasiveness evaluation, is an urgent but unmet need. In this study, we developed a hybrid hydrogel system composed of GelMA and hydrolyzed collagen to model tumor micro-environment and tested with several cancer cells with different origin and characteristics. This hydrogel possesses a well-ordered homogenous microstructure, excellent permeability and an adjustable mechanical stiffness. This hydrogel demonstrated similar properties as Matrigel in tumor spheroids culture and 3D tumor invasiveness studies. It was further applied in a Tumor-on-a-Chip system with 3D-bioprinting. Our research demonstrated this hydrogel's effectiveness in tumor 3D culture, and its potential to replace Matrigel in cancer invasiveness evaluation.

A method for determining methylation density of target CpG islands has been established. In the method, DNA microarray was prepared by spotting a set of PCR products amplified from bisulfite-converted sample DNAs. The PCR products on the microarray were treated by SssI methyltransferase and labeled with TAMRA fluorescence. A recombinant, antibody-like methyl-CpG-binding protein labeled with Cy5 fluorescence was used to identify symmetrical methyl-CpG dinucleotide of the PCR products on the microarray. By use of a standard curve with control mixtures, the ratio of two fluorescence signals can be converted into percentage values to assess methylation density of targeted fragments. We obtained the methylation density of six CpG islands on the two tumor suppressor genes of CDK2A and CDK2B from seven cancer cell line samples and two normal blood samples. The validity of this method was tested by bisulfite sequencing. This method not only allows the quantitative analysis of regional methylation density of a set of given genes but also could provide information of methylation density for a large amount of clinical samples.

Aberrant DNA methylation of the CpG islands for cancer‐related genes is among the earliest and most frequent alterations in cancer and may be useful for diagnosing cancer or evaluating recurrent disease.

Background DNA methylation based techniques are important tools in both clinical diagnostics and therapeutics. But most of these methods only analyze a few CpG sites in a target region. Indeed, difference of site-specific methylation may also lead to a change of methylation density in many cases, and it has been found that the density of methylation is more important than methylation of single CpG site for gene silencing. Results We have developed a novel approach for quantitative analysis of CpG methylation density on the basis of microarray-based hybridization and incorporation of Cy5-dCTP into the Cy3 labeled target DNA by using Taq DNA Polymerase on microarray. The quantification is achieved by measuring Cy5/Cy3 signal ratio which is proportional to methylation density. This methylation-sensitive technique, termed RMEAM (regional methylation elongation assay on microarray), provides several advantages over existing methods used for methylation analysis. It can determine an exact methylation density of the given region, and has potential of high throughput. We demonstrate a use of this method in determining the methylation density of the promoter region of the tumor-related gene MLH1, TERT and MGMT in colorectal carcinoma patients. Conclusion This technique allows for quantitative analysis of regional methylation density, which is the representative of all allelic methylation patterns in the sample. The results show that this technique has the characteristics of simplicity, rapidness, specificity and high-throughput.

Objectives: Molecular margin analysis is considered more sensitive in detecting preneoplastic lesions and residual cancer cells than conventional histological margin examination. Hence, we examined MGMT expression profile and methylation status in histologically negative margins of colorectal cancer patients.Design and methods: This study included 24 colorectal tumor tissues and corresponding negative surgical margin tissues. MGMT promoter methylation patterns were analyzed by using methylation-specific oligonucleotide microarray. In addition, MGMT protein expression was analyzed by immunohistochemistry. MGMT clinical significance was evaluated together with other well-known clinicopathological factors.Results: Extensive MGMT promoter methylation was observed in tumor tissues; a moderate methylation level was found in surgical margin tissues and little or no methylation was observed in the normal control. There was a trend towards longer overall survival for those patients with negative MGMT immunostaining in surgical margins.Conclusions: MGMT expression negative in surgical margin tissues indicates longer overall survival for colorectal tumor patients. (c) 2007 The Canadian Society of Clinical Chemists. Published by Elsevier Inc. All rights reserved.

An accurate, simple, and sensitive reversed-phase high-performance liquid chromatographic method, with loratadine as internal standard (IS) and UV detection at 286 nm, has been developed for deterination of cystine in human urine. The major innovations of the method include use of acrylonitrile to protect cysteine from oxidization to cystine, separation of cysteine, as the dansyl derivative, from cystine, and use of isocratic elution instead of gradient elution to reduce the time and cost of serial analysis. The mobile phase was 0.05 M sodium acetate–methanol, 35:65 (v/v), adjusted to pH 3.5 with 2.5 M citric acid, at a flow rate of 1.0 mL min−1. The retention times of cystine and the IS were 16.6 and 19.9 min, respectively. The limit of detection for cystine was 0.3 mg L−1. Extraction recovery of cystine was >85.6%. Intra-day and inter-day precision (RSD) for cystine were below 4.3 and 8.5%, respectively. There was no chromatographic interference from other α-amino acids present in mammalian proteins, or from other urine components. The calibration plot for the cystine derivative was linear in the range 1–500 mg L−1 and the correlation coefficient was 0.9992. The method was validated appropriately and successfully used for determination of cystine in human urine.

We have developed a novel method for detecting DNA methylation status of multiple samples, in which the DNA samples were firstly immobilized on the slide and treated with bisulfite directly on the chip. In this experiment, DNAs of pUC19 plasmid were restricted by the enzymes, and ligated with a linker bearing 5'-terminal acrylamide group at the sticky ends. Using universal acrylamide gel polymerization technique, a large amount of DNAs could be immobilized on the slide. The immobilized DNAs were converted by soaking the chip in bisulfite reaction mixtures for 16 h. The probes for detection of the methylation patterns of CpG sites hybridized with the converted DNAs on the microarray, and non-specifically bound probes were cleaned by electrophoresis. We have optimized the experimental conditions of both bisulfite treatment and electrophoresis to increase sensitivity and specificity. The results were further validated by bisulfite DNA sequencing. The experiments show that the method can simplify the experimental processes and increase the efficiency of the bisulfite treatment. This novel method could be used as a convenient tool to detect the methylation status of the multiple genes for a large amount of samples in the future.