Universal growth of perovskite thin monocrystals from high solute flux for sensitive self-driven X-ray detection.

Metal-halide perovskite thin monocrystals featuring efficient carrier collection and transport capabilities are well suited for radiation detectors, yet their growth in a generic, well-controlled manner remains challenging. Here, we reveal that mass transfer is one major limiting factor during solution growth of perovskite thin monocrystals. A general approach is developed to overcome synthetic limitation by using a high solute flux system, in which mass diffusion coefficient is improved from 1.7×10-10 to 5.4×10-10 m2 s-1 by suppressing monomer aggregation. The generality of this approach is validated by the synthesis of 29 types of perovskite thin monocrystals at 40-90 °C with the growth velocity up to 27.2 µm min-1. The as-grown perovskite monocrystals deliver a high X-ray sensitivity of 1.74×105 µC Gy-1 cm-2 without applied bias. The findings regarding limited mass transfer and high-flux crystallization are crucial towards advancing the preparation and application of perovskite thin monocrystals.

GaN/Gr (2D)/Si (3D) Combined High-Performance Hot Electron Transistors.

To overcome the problem of minority carrier storage time in bipolar transistors, a hot electron transistor (HET) has been proposed. This device has the advantage of high working speed and some complex logic functions can be completed by using one component. Here, we demonstrate a mixed-dimensional HET composed of GaN/AlN microwires, graphene (Gr), and Si. The electrons between GaN/AlN are injected into graphene by an F-N tunneling mechanism to achieve high speed hot electrons, then cross graphene by ballistic transport, and are collected in a nearly lossless manner through a low-barrier Si. Therefore, the device shows a record DC gain of 16.2, a collection efficiency close to the limit of 99.9% based on the graphene hot electron transistor (GHET), an emitter current density of about 68.7 A/cm2, and a high on/off current ratio reaching ∼107. Meanwhile, the current saturation range is wide, beyond those of most GHETs. It has potential applications as a power amplifier.

Highly Sensitive and Selective Detection of Pharmaceuticals on Au/MIL-101(Cr) by SERS.

The detection of pharmaceuticals has been a matter of concern among scientists and health researchers in the past few decades. However, it is still difficult to realize the sensitivity and selectivity detection of pharmaceuticals with similar structures. Herein, the pharmaceutical molecules of 2-mercaptobenzimidazole (MBI) and 2-mercaptobenzothiazole (MBT) with so similar structures can be selectively detected by surface-enhanced Raman spectroscopy (SERS) taking advantage of the fingerprint identification on Au/MIL-101(Cr), with sensitive detection limits of 0.5 ng·mL-1 for MBI and 1 ng·mL-1 for MBT. MBI is selectively enriched by Au/MIL-101(Cr) from the mixture solution and detected by SERS below 30 ng·mL-1. MBI can also be selectively detected in the serum samples with a detection limit of 10 ng·mL-1. Density functional theory calculations combined with the SERS experiments explained that the high sensitivity and selectivity are caused by the intrinsic differences in Raman intensity and different adsorption energies from the pharmaceutical molecules adsorbed on Au/MIL-101(Cr), respectively. This study provides an effective way to enrich and detect pharmaceutical molecules with similar structures.

Two-In-One: End-Emitting Blue LED and Self-Powered UV Photodetector based on Single Trapezoidal PIN GaN Microwire for Ambient Light UV Monitoring and Feedback.

With the continuous miniaturization and integration of the semiconductor industry, micro/nanoscale integrated photonics has received extensive attention as a key technology for optical communication, optical storage, and optical interconnection. Here, a two-in-one device is reported with both unidirectional blue light emission and UV photodetection functions based on single trapezoidal PIN GaN microwire. By constructing a Fabry-Perot resonator cavity structure, the end-emitting blue light-emitting diode with a low turn-on voltage (≈0.97 V) and high color purity (full width at half maximum ≈22 nm) is implemented. Furthermore, benefiting from the slow growth rate of the semipolar planes on both sides of the trapezoidal microwire and the high diffuse reflectivity of the patterned substrate, the trapezoidal microwire sides can be used as a high-performance UV photodetector. In self-driven mode, the device exhibits a large responsivity (0.218 A W-1 ), high external quantum efficiency (83.31%) and fast response speed (rise/decay time of 0.48/0.98 ms). Finally, the prepared two-in-one device is successfully integrated into ambient light UV monitoring and feedback system and tested. This work provides a novel strategy to combine luminescence with photodetection, demonstrating high potential for applications, such as on-chip photonic integration, energy-saving communication and ambient light monitoring and feedback system.

Evaluation of the household solid waste mandatory sorting policy in Shanghai: A 1-year public opinion survey.

Sustainable management of household solid waste (HSW) is an essential step in realizing the development of a circular economy (CE). However, for many developing countries, HSW sorting is evolving incrementally, and focusing on the intervention role of policy and the sorting behaviour of residents can help achieve sustainable waste management. This study aims to investigate the main determinants of residents' HSW sorting behaviour and how policy particularly contributes to it. Drawing upon the theory of planned behaviour (TPB) and incorporating experiences, a conceptual framework is tested on a sample of Chinese residents in Shanghai (n = 560, from November to December 2020) using structural equation modelling analysis. The empirical results show that experience and behavioural intention greatly influence HSW sorting behaviour. Moreover, the positive attitude of residents promotes the success of HSW sorting. Subjective norms and perceived behaviour control indirectly affect behavioural intention and behaviour via attitude. The findings of this study provide policymakers with critical factors for the successful implementation of HSW sorting. We also propose policy implications to maintain and improve sorting efficiency from the perspective of residents (education, communication and publicity), neighbourhood committees (degree and efficiency of supervision) and property management companies (good infrastructure, services and processes).

Fullerene-Liquid-Crystal-Induced Micrometer-Scale Charge-Carrier Diffusion in Organic Bulk Heterojunction.

The short charge-carrier diffusion length (LD ) (100-300 nm) in organic bulk heterojunction (BHJ) impedes the further improvement in power conversion efficiency (PCE) of organic solar cells (OSCs), especially for thick-film (>400 nm) devices matching with industrial solution processing. Here a facile method is developed to efficiently increase LD and then improve PCEs of OSCs via introducing a fullerene liquid crystal, F1, into the active layer. F1 combines the inherent high electron mobility of fullerene and strong self-assembly capacity of liquid crystal, providing a fast channel for charge-carrier transport and reducing energetic disorder and trap density in BHJ film via enhancing crystallization. Typically, in PM6:Y6:F1 BHJ, the enhanced charge-carrier mobility (>10-2 cm-2 V-1 s-1 ) and prolonged charge-carrier lifetime (55.3 µs) are acquired to realize the record LD of 1.6 or 2.4 µm for electron or hole, respectively, which are much higher than those of the PM6:Y6 binary sample and comparable to or even better than those values reported for some inorganic/hybrid materials, such as CuInx Ga(1- x ) Se2 (CIGS) and perovskite thin films. Benefitting from the micrometer-scale LD , the PM6:Y6:F1 ternary OSCs sustain a remarkable PCE of 15.23% with the active layer thickness approaching 500 nm.

A high-performance polarization-sensitive and stable self-powered UV photodetector based on a dendritic crystal lead-free metal-halide CsCu2I3/GaN heterostructure.

Polarization-sensitive photodetectors are the core of optics applications and have been successfully demonstrated in photodetectors based on the newly-emerging metal-halide perovskites. However, achieving high polarization sensitivity is still extremely challenging. In addition, most of the previously reported photodetectors were concentrated on 1D lead-halide perovskites and 2D asymmetric intrinsic structure materials, but suffered from being external bias driven, lead-toxicity, poor stability and complex processes, severely limiting their practical applications. Here, we demonstrate a high-performance polarization-sensitive and stable polarization-sensitive UV photodetector based on a dendritic crystal lead-free metal-halide CsCu2I3/GaN heterostructure. By combining the anisotropic morphology and asymmetric intrinsic structure of CsCu2I3 dendrites with the isotropic material GaN film, a high specific surface area and built-in electric field are achieved, exhibiting an ultra-high polarization selectivity up to 28.7 and 102.8 under self-driving mode and -3 V bias, respectively. To our knowledge, such a high polarization selectivity has exceeded those of all of the reported perovskite-based devices, and is comparable to, or even superior to, those of the conventional 2D heterostructure materials. Interestingly, the unsealed device shows outstanding stability, and can be stored for over 2 months, and effectively maintained the performance even after repeated heating (373K)-cooling (300K) for different periods of time in ambient air, indicating a remarkable temperature tolerance and desired compatibility for applications under harsh conditions. Such excellent performance and simple method strongly show that the CsCu2I3/GaN heterojunction photodetector has great potential in practical applications with high polarization-sensitivity. This work provides a new insight into designing novel high-performance polarization-sensitive optoelectronic devices.

A Self-Formed Stable PbI2 /NiOx Interface with Increased Ni3+ Centers for Perovskite Photovoltaics.

Nickel oxide (NiOx ) is a promising hole transport material (HTM) for perovskite photovoltaics owing to its chemical stability and low cost. However, most NiOx based solar cells deliver relatively weak performance because of its insufficient electrical property and interfacial contact. In this work, a self-formed PbI2 /NiOx interface was developed to stabilize the Ni3+ centers, which was beneficial for electrical transport and band alignment in perovskite solar cells. Combined with ultraviolet ozone treatment (UVO) and sequential deposition, the density of Ni3+ centers was greatly increased and could be stabilized by the PbI2 interface. These merits contributed coordinately to the fast hole extraction and low energy loss across the PbI2 /NiOx interface, yielding power conversion efficiencies (PCEs) of over 19 %.

Circ_0020123 enhances the cisplatin resistance in non-small cell lung cancer cells partly by sponging miR-140-3p to regulate homeobox B5 (HOXB5).

Cisplatin (DDP) therapy is widely used for the treatment of non-small cell lung cancer (NSCLC), but the curative effect is limited by chemoresistance. This study was designed to explore circ_0020123 function in DDP resistance of NSCLCDDP. Expression detection for circ_0020123, microRNA-140-3p (miR-140-3p) and homeobox B5 (HOXB5) was performed by real-time polymerase chain reaction (qRT-PCR). Half inhibitory concentration (IC50) of DDP and cell proliferation was detected by Cell Counting Kit-8 (CCK-8) assay. Colony formation ability was assessed using colony formation assay. Cell migration and invasion were evaluated via transwell assay. Cell apoptosis was examined by flow cytometry. Protein analysis was conducted by Western blot. Dual-luciferase reporter assay was used to affirm target interaction. Circ_0020123 expression was upregulated in DDP-resistant NSCLC cells. DDP resistance was reduced by downregulation of circ_0020123 in NSCLC cells. Circ_0020123 was identified as a miR-140-3p sponge. The effect of si-circ_0020123 on DDP resistance was partly associated with miR-140-3p upregulation. HOXB5 was a downstream target for miR-140-3p. Overexpression of HOXB5 mitigated miR-140-3p-induced inhibition of DDP resistance in NSCLC cells. Circ_0020123 upregulated the level of HOXB5 partly via sponging miR-140-3p. Also, circ_0020123 promoted tumor growth in NSCLC/DDP xenografts by regulating miR-140-3p and HOXB5 levels at least in part. These results revealed that circ_0020123 promoted DDP resistance in NSCLC cells partly by targeting miR-140-3p/HOXB5 axis, indicating that circ_0020123 might be used as a molecular target in DDP treatment for NSCLC.

Circ-SNAP47 (hsa_circ_0016760) and miR-625-5p are regulators of WEE1 in regulation of chemoresistance, growth and invasion of DDP-tolerant NSCLC cells via ceRNA pathway.

Circular RNA-synaptosome associated protein 47 (circ-SNAP47; Hsa_circ_0016760) is oncogenic in non-small-cell lung cancer (NSCLC); however, its role is undescribed in cis-diamminedichloroplatinum II (DDP) resistance. We attempted to investigate its expression, role and mechanism in DDP-tolerant NSCLC. As a result, circ-SNAP47 expression was upregulated in human DDP-tolerant NSCLC tissues and cells, accompanied with WEE1 G2 checkpoint kinase (WEE1) upregulation and microRNA (miR)-625-5p downregulation. Functionally, interfering circ-SNAP47 and/or restoring miR-625-5p curbed the 50% inhibitory concentration of DDP, colony formation, cell proliferation and invasion, accompanied with apoptotic rate promotion and depressions of multidrug resistance (MDR) markers MDR1 and MRP1, anti-apoptosis protein Bcl-2, and pro-invasion protein MMP9. Notably, circ-SNAP47 interference suppressed xenograft tumor growth of DDP-tolerant NSCLC cells by elevating miR-625-5p and descending WEE1. Mechanistically, circ-SNAP47 directly targeted miR-625-5p, and miR-625-5p further targeted WEE1. Therefore, circ-SNAP47-miR-625-5p-WEE1 axis might participate in chemoresistance and progression of DDP-tolerant NSCLC.

MALAT1 Promotes Cell Tumorigenicity Through Regulating miR-515-5p/EEF2 Axis in Non-Small Cell Lung Cancer.

BACKGROUND: Previous studies suggested long noncoding RNA metastasis associated with lung adenocarcinoma transcript 1 (lncRNA MALAT1) acted as a tumor promoter to promote cell carcinogenesis in non-small cell lung cancer (NSCLC). MALAT1 was found to exist in serum exosomes of several cancers. However, the role of exosomal-derived MALAT1 in NSCLC remains poorly understood. MATERIALS AND METHODS: Exosomes were isolated using the ExoQuick precipitation kit. Western blot was used to detect the protein expression of CD3, CD63, apoptosis- and metastasis-related protein. The expression of MALAT1, microRNA (miR)-515-5p and eukaryotic elongation factor 2 (EEF2) mRNA was detected using quantitative real-time polymerase chain reaction. Cell viability, apoptosis, or invasion were measured using 3-(4, 5)-dimethylthiahiazo (-z-y1)-3, 5-di-phenytetrazoliumromide (MTT) assay, flow cytometry or transwell assay, respectively. The interaction between miR-515-5p and MALAT1 or EEF2 was confirmed by dual-luciferase reporter assay. In vivo experiments were conducted through the murine xenograft model. RESULTS: MALAT1 was highly expressed in serum and cell exosomes from NSCLC patients. MALAT1 knockdown repressed cell proliferation, invasion and induced cell apoptosis in vitro as well as inhibited tumor growth in vivo in NSCLC. Subsequently, we confirmed that MALAT1 was a sponge of miR-515-5p, and EEF2 was a target of miR-515-5p. Furthermore, MALAT1 served as a sponge of miR-515-5p to regulate EEF2 expression in NSCLC cells. More importantly, MALAT1 deletion  performed anti-tumor effects by interacting with miR-515-5p/EEF2 axis in vitro and in vivo in NSCLC. CONCLUSION: MALAT1 knockdown repressed NSCLC tumorigenicity by inhibiting cell proliferation, invasion and promoting apoptosis through regulating miR-515-5p/EEF2, besides, MALAT1 was highly enriched in exosomes of NSCLC, suggesting a possible molecular-targeted therapy for NSCLC patients.

SEPT9_v2, frequently silenced by promoter hypermethylation, exerts anti-tumor functions through inactivation of Wnt/ß-catenin signaling pathway via miR92b-3p/FZD10 in nasopharyngeal carcinoma cells.

BACKGROUND: Nasopharyngeal carcinoma tends to present at an advanced stage because the primary anatomic site is located in a less visible area and its clinical symptoms are nonspecific. Prognosis of advanced nasopharyngeal carcinoma cases remains disappointing. SEPT9 is a methylation-based biomarker approved by the US Food and Drug Administration for colorectal cancer screening and diagnosis. Interestingly, downregulation of SEPT9, especially SEPT9_v2, mediated by promoter hypermethylation has been also detected in head and neck squamous cell carcinoma than in head and neck squamous epithelium, while other SEPT9 variants did not. These reasons above indicate a crucial role of SEPT9_v2 in cancer progression. Therefore, we address the methylation status of SEPT9_v2 in nasopharyngeal carcinoma and explore the role of SEPT9_v2 in nasopharyngeal carcinoma proliferation and cancer progression. RESULTS: SEPT9_v2 expression was found to be downregulated via promoter methylation in nasopharyngeal carcinoma cell lines and tissues. Ectopic expression of SEPT9_v2 induced G0/G1 cell cycle arrest and apoptosis, which exerted an inhibitory effect in cell proliferation and colony formation. Additionally, nasopharyngeal carcinoma cell migration and invasion were shown to be inhibited by SEPT9_v2. Furthermore, our data suggested that SEPT9_v2 inhibits proliferation and migration of nasopharyngeal carcinoma cells through inactivation of the Wnt/ß-catenin signaling pathway via miR92b-3p/FZD10. CONCLUSIONS: This study delineates SEPT9_v2, frequently silenced by promoter hypermethylation, exerts anti-tumor functions through inactivation of the Wnt/ß-catenin signaling pathway via miR92b-3p/FZD10 in nasopharyngeal carcinoma cells and, hence, SEPT9_v2 may be a promising therapeutic target and biomarker for nasopharyngeal carcinoma.

Coping with waste: A government-NGO collaborative governance approach in Shanghai.

Complex environmental issues are leading local governments to collaborate with non-governmental organizations (NGOs) in the urban environmental governance sphere. While previous studies have emphasized how the Chinese government engages NGOs in service contracting to meet rising service demands, they have not provided empirical evidence of the outcomes of these collaborations at a local level. Based on a mixed methods research design developed from May 2016 to February 2017 in Shanghai, the impact of Aifen, an environmental NGO, is assessed in the context of municipal solid waste management. A total of 400 questionnaires were completed. 200 questionnaires in 10 communities where Aifen developed its activities and 200 questionnaires in 10 communities where no environmental NGO activities were accomplished. The results show that a local government-NGO collaborative governance approach enhances public participation and respond to state decentralization and rising environmental issues in urban areas.

A factor analysis of residents' performance in municipal solid waste source-separated collection: A case study of pilot cities in China.

To explore the potential effectiveness of a localized waste recycling system in Chinese cities, several rounds of a municipal solid waste source-separated collection (MSWSC) program were implemented throughout China from 2000 to 2017. In our study, to evaluate the achievements of the MSWSC program, a structured questionnaire survey and face-to-face interviews were conducted in eight representative cities from the MSWSC pilot cities. Influencing factors were examined via a Hierarchical Linear Model (HLM) on both the individual level and the city level. The differences in MSWSC performance among the eight research cities were investigated through a comparative analysis. The results suggested that gender, age, knowledge of MSWSC, satisfaction with sanitation and satisfaction with publicity had significant impacts on MSWSC, and we further found that the city-level factors influenced the relationship between MSWSC performance and the individual-level variables. Differences among the eight research sites indicated that Nanjing and Hangzhou exhibited relatively high achievements in the implementation of MSWSC program, while Yichun and Guiyang showed poor performance. The experiences of these advanced pilot cities suggest that specific containers for designated waste types, widespread public education, and sufficient MSWSC incentives must be provided and publicized to promote municipal solid waste recycling behaviors. Given the unique status of municipal solid waste management in China and its regional heterogeneity, the MSWSC system should be further discussed with regard to local conditions in a wider range of city settings. Implications: This study attempts to discuss the factors affecting performance on municipal solid waste source-separated collection (MSWSC) by considering the nested data of two levels of individual and city from a structured questionnaire survey. Therefore, a Hierarchical Linear Model is established which can analyze the intra-group and inter-group effects of two-level variables. The proposed method can be expanded to other cities to determine the main factors affecting MSWSC or to evaluate the residents' performance on MSWSC.

The Effect of Sympathetic Denervation on Cerebral Arteriogenesis After Chronic Cerebral Hypoperfusion.

OBJECTIVE: To explore the effect of perivascular sympathetic nerve on cerebral collateral arteriogenesis in chronic cerebral hypoperfusion models of rats. MATERIALS AND METHODS: Chronic cerebral hypoperfusion model was established by right common carotid artery ligation for 8 weeks, while sympathetic denervation was performed by superior cervical ganglionectomy. The male Sprague-Dawley rats were randomly divided into 4 groups including sham group (n = 21), denervation group (n = 21), artery ligation group (n = 21) and combined group with both artery ligation and denervation (n = 21). After 8 weeks of surgery, the rats in each group were randomly divided into 3 subgroups including subgroup A (n = 7), subgroup B (n = 7) and subgroup C (n = 7). The 3 subgroups were subjected to latex perfusion, permanent right middle cerebral artery occlusion and immunohistochemical staining, respectively. RESULTS: The diameters of right leptomeningeal anastomoses in artery ligation group significantly enlarged compared with sham group. When sympathetic denervation was performed in the presence of artery ligation, diameter of collateral vessel decreased, although larger than in sham group. After 8 weeks of permanent right middle cerebral artery occlusion, the cerebral perfusion over the right middle cerebral artery area in combined group was significantly lower than in artery ligation group, although both were higher than in denervation group and sham group. Triphenyltetrazolium chloride staining showed that cerebral infarct volume in combined group was significantly larger than in artery ligation group, and smaller than in denervation group and sham group. Neurologic functional scoring showed that scores in combined group were significantly higher than in artery ligation group, and lower than in denervation group and sham group. Immunohistochemical staining for α-smooth muscle actin showed that compared with sham group, tunica media thickness of right leptomeningeal anastomoses in artery ligation group increased significantly. Thickness in combined group was thinner than in artery ligation group, although thicker than in sham group. CONCLUSIONS: Perivascular sympathetic denervation can impair the cerebral collateral arteriogenesis under condition of chronic cerebral hypoperfusion.

Hyperbaric oxygen preconditioning ameliorates blood-brain barrier damage induced by hypoxia through modulation of tight junction proteins in an in vitro model.

AIM: To explore the effects of hyperbaric oxygen preconditioning (HBOP) on the permeability of blood-brain barrier (BBB) and expression of tight junction proteins under hypoxic conditions in vitro. METHODS: A BBB in vitro model was constructed using the hCMEC/D3 cell line and used when its trans-endothelial electrical resistance (TEER) reached 80-120 Ω · cm2 (tested by Millicell-Electrical Resistance System). The cells were randomly divided into the control group cultured under normal conditions, the group cultured under hypoxic conditions (2%O2) for 24 h (hypoxia group), and the group first subjected to HBOP for 2 h and then to hypoxia (HBOP group). Occludin and ZO-1 expression were analyzed by immunofluorescence assay. RESULTS: Normal hCMEC/D3 was spindle-shaped and tightly integrated. TEER was significantly reduced in the hypoxia (P=0.001) and HBOP group (P=0.014) compared to control group, with a greater decrease in the hypoxia group. Occludin membranous expression was significantly decreased in the hypoxia group (P=0.001) compared to the control group, but there was no change in the HBOP group. ZO-1 membranous expression was significantly decreased (P=0.002) and cytoplasmic expression was significantly increased (P=0.001) in the hypoxia group compared to the control group, although overall expression levels did not change. In the HBOP group, there was no significant change in ZO-1 expression compared to the control group. CONCLUSION: Hyperbaric oxygen preconditioning protected the integrity of BBB in an in vitro model through modulation of occludin and ZO-1 expression under hypoxic conditions.

Novel amperometric aptasensor based on analyte-induced suppression of enzyme catalysis in polymeric bionanocomposites.

We report on a novel label-free biosensing interface based on multifunctional polymeric bionanocomposites (PBNCs) and its application for sensitive detection of protein based on the analyte-induced suppression of enzymatic catalysis in PBNCs. Thrombin and its aptamer are adopted as a model system to construct an amperometric aptasensor. First, polydopamine-based PBNCs with glucose oxidase (GOx) entrapped at high load/activity and Au nanoparticles (AuNPs) dispersed in high abundance on the surface were prepared through a chemical/biochemical synthesis method, as proven by UV-vis spectrophotometry, digital imaging, and transmission electron microscopy. Then, the PBNCs were cast-coated onto an Au electrode. The PBNC-modified Au electrode presented a high chronoamperometric sensitivity of 113 ± 2 µA cm(-2) mM(-1) to glucose, as well as a high capability of immobilizing the aptamer through the surficial AuNPs to fabricate a label-free aptasensing interface. The binding of thrombin to the aptasensor surface significantly hindered the mass-transfer of the enzymatic substrates/products and thus suppressed the enzymatic catalysis efficiency, which produced obvious signal change through measuring the electrooxidation of enzymatically generated H(2)O(2). The thus-prepared aptasensor could detect thrombin with a broad detection range (1-100 nM), a detection limit down to 0.1 nM, and satisfactory specificity. The developed aptasensing method may find broad applications in the fields of clinical diagnosis, environmental protection, and food safety.

Erythropoietin combined with granulocyte colony­stimulating factor enhances MMP-2 expression in mesenchymal stem cells and promotes cell migration.

Mesenchymal stem cells (MSCs) are promising clinical tools, but the molecular mechanisms that regulate the mobilization and homing of MSCs and cause invasion through extracellular matrix (ECM) barriers are unknown. Matrix metalloproteinase (MMP) degrades the ECM and promotes cell migration. In this study, we investigated MMP expression and cell migration after treatment with erythropoietin (EPO) and granulocyte colony-stimulating factor (G-CSF). Specifically, we studied whether EPO combined with G-CSF enhanced MMP expression and increased the in vitro motility of MSCs. Real-time PCR was used to detect the mRNA of MMPs and tissue inhibitors of metalloproteinase. Cell migration was evaluated by transwell and wound healing assays. Western blotting was used to detect changes in ERK1/2 protein levels. The results showed that EPO combined with G-CSF enhanced MMP-2 expression in MSCs, promoted MSC motility and activated the ERK1/2 signaling pathway. Thus, a combination treatment of EPO with G-CSF promoted cell migration by stimulating MMP-2 expression in MSCs and this appeared to be related to the ERK1/2 signaling pathway.

Increased expression of IL-6 mRNA in hepatocellular carcinoma cell lines correlates with biological characteristics.

BACKGROUND AND AIMS: IL-6 has been implicated in both virus-associated and diethylnitrosamine-induced hepatocellular carcinomas (HCCs). Generally it is produced by immune cells such as Kupffer cells in the liver. To understand mechanisms by which IL-6 might participate in the genesis of HCCs, the production of IL-6 by cell lines under different conditions was examined to determine inducing factors. METHODS: Expression of IL-6 mRNA in both hepatoma cell lines and a normal liver cell line L-02 was measured by quantitative RT-PCR. Biological molecules including liposome, dsRNA and cell debris were used to stimulate IL-6 mRNA expression in HepG2 cells and inhibition was effected by RNAi. Proliferation was assessed by MTT and clone formation and migration was determined by scratch assay. RESULTS: All of the HCC cell lines observed expressed IL-6 mRNA, including HepG2, Bel-7402(7402), MHCC-97H and SMMC-7721.Normal liver cell line L-02 also expressed IL-6 mRNA. SiRNA to IL-6 specifically knockdowned IL-6 mRNA expression in HepG2, and liposome, dsRNA and cell debris increased it. Both proliferation and migration of HepG2 cells were related to the level of IL-6 HepG2 expressed. CONCLUSION: Both normal liver cell line and HCC cell lines can produce IL-6 so that Kupffer cells are noit the only source of the cytokine in the liver well as other immune cells. That the fact that HCC cells reacted to stimulation of biological molecules such as liposome, dsRNA or cell debris with increasing production of IL-6 indicates that the cytokine might play an important role not only in the period of tumor initiation but progression and recurrence as well.