Theoretical Study on Ion Diffusion Mechanism in W-Doped K3SbS4 as Solid-State Electrolyte for K-Ion Batteries.

The development of a solid-state electrolyte (SSE) is crucial for overcoming the side reactions of metal potassium anodes and advancing the progress of K-ion batteries (KIBs). Exploring the diffusion mechanism of the K ion in SSE is important for deepening our understanding and promoting its development. In this study, we conducted static calculations and utilized deep potential molecular dynamics (DeepMD) to investigate the behavior of cubic K3SbS4. The original K3SbS4 exhibited poor ionic conductivity, but we discovered that introducing heterovalent tungsten doping created vacancies, which significantly reduced the activation energy to 0.12 eV and enhanced the ionic conductivity to 1.80 × 10-2 S/cm. The diffusion of K-ions in K3SbS4 primarily occurs through the exchange of positions with K vacancies. This research provides insights into the design of SSE with high ionic conductivity. Furthermore, it highlights the effectiveness of DeepMD as a powerful tool for studying the SSE.

Risk factors for cerebral edema following aneurysm clipping in patients with aneurysmal subarachnoid hemorrhage.

OBJECTIVES: To investigate the factors that contribute to the development of cerebral edema after aneurysm clipping in individuals with aneurysmal subarachnoid hemorrhage (aSAH). METHODS: A total of 232 patients with aSAH caused by rupture and treated with aneurysm clipping were included in the retrospective analysis of clinical data. Postoperatively, the participants were categorized into two groups based on the presence or absence of cerebral edema: a complication group (n=33) and a non-complication group (n=199).A comparison was made between the overall data of the 2 groups. RESULTS: In the complication group, there were higher proportions of patients experiencing recurrent bleeding, aneurysm in the posterior circulation, Fisher grade III-IV, World Federation of Neurosurgical Societies (WFNS) grade II, Hunt-Hess grade III-IV, concomitant hypertension, duration from onset to operation ≥12 h, and concomitant hematoma compared to the non-complication group (p<0.05). Cerebral edema after aneurysm clipping was associated with several risk factors including repeated bleeding, aneurysm in the back of the brain, Fisher grade III-IV, WFNS grade II, Hunt-Hess grade III-IV, simultaneous high blood pressure and hematoma, and a duration of at least 12 hours from the start of symptoms to the surgical procedure (p<0.05). CONCLUSION: In patients with aSAH, the risk of cerebral edema after aneurysm clipping is increased by recurrent bleeding, aneurysm in the posterior circulation, Fisher grade III-IV, WFNS grade II, Hunt-Hess grade III-IV, concomitant hypertension and hematoma, and duration of ≥12 h from onset to operation.

Subclass Effects on Self-Association and Viscosity of Monoclonal Antibodies at High Concentrations.

The effects of a subclass of monoclonal antibodies (mAbs) on protein-protein interactions, formation of reversible oligomers (clusters), and viscosity (η) are not well understood at high concentrations. Herein, we quantify a short-range anisotropic attraction between the complementarity-determining region (CDR) and CH3 domains (KCDR-CH3) for vedolizumab IgG1, IgG2, or IgG4 subclasses by fitting small-angle X-ray scattering (SAXS) structure factor Seff(q) data with an extensive library of 12-bead coarse-grained (CG) molecular dynamics simulations. The KCDR-CH3 bead attraction strength was isolated from the strength of long-range electrostatic repulsion for the full mAb, which was determined from the theoretical net charge and a scaling parameter ψ to account for solvent accessibility and ion pairing. At low ionic strength (IS), the strongest short-range attraction (KCDR-CH3) and consequently the largest clusters and highest η were observed with IgG1, the subclass with the most positively charged CH3 domain. Furthermore, the trend in KCDR-CH3 with the subclass followed the electrostatic interaction energy between the CDR and CH3 regions calculated with the BioLuminate software using the 3D mAb structure and molecular interaction potentials. Whereas the equilibrium cluster size distributions and fractal dimensions were determined from fits of SAXS with the MD simulations, the degree of cluster rigidity under flow was estimated from the experimental η with a phenomenological model. For the systems with the largest clusters, especially IgG1, the inefficient packing of mAbs in the clusters played the largest role in increasing η, whereas for other systems, the relative contribution from stress produced by the clusters was more significant. The ability to relate η to short-range attraction from SAXS measurements at high concentrations and to theoretical characterization of electrostatic patches on the 3D surface is not only of fundamental interest but also of practical value for mAb discovery, processing, formulation, and subcutaneous delivery.

Characterizing Protein-Protein Interactions and Viscosity of a Monoclonal Antibody from Low to High Concentration Using Small-Angle X-ray Scattering and Molecular Dynamics Simulations.

Understanding protein-protein interactions and formation of reversible oligomers (clusters) in concentrated monoclonal antibody (mAb) solutions is necessary for designing stable, low viscosity (η) concentrated formulations for processing and subcutaneous injection. Here we characterize the strength (K) of short-range anisotropic attractions (SRA) for 75-200 mg/mL mAb2 solutions at different pH and cosolute conditions by analyzing structure factors (Seff(q)) from small-angle X-ray scattering (SAXS) using coarse-grained molecular dynamics simulations. Best fit simulations additionally provide cluster size distributions, fractal dimensions, cluster occluded volume, and mAb coordination numbers. These equilibrium properties are utilized in a model to account for increases in viscosity caused by occluded volume in the clusters (packing effects) and dissipation of stress across lubricated fractal clusters. Seff(q) is highly sensitive to K at 75 mg/mL where mAbs can mutually align to form SRA contacts but becomes less sensitive at 200 mg/mL as steric repulsion due to packing becomes dominant. In contrast, η at 200 mg/mL is highly sensitive to SRA and the average cluster size from SAXS/simulation, which is observed to track the cluster relaxation time from shear thinning. By analyzing the distribution of sub-bead hot spots on the 3D mAb surface, we identify a strongly attractive hydrophobic patch in the complementarity determining region (CDR) at pH 4.5 that contributes to the high K and consequently large cluster sizes and high η. Adding NaCl screens electrostatic interactions and increases the impact of hydrophobic attraction on cluster size and raises η, whereas nonspecific binding of Arg attenuates all SRA, reducing η. The hydrophobic patch is absent at higher pH values, leading to smaller K, smaller clusters, and lower η. This work constitutes a first attempt to use SAXS and CG modeling to link both structural and rheological properties of concentrated mAb solutions to the energetics of specific hydrophobic patches on mAb surfaces. As such, our work opens an avenue for future research, including the possibility of designing coarse-grained models with physically meaningful interacting hot spots.

Clinically significant genomic alterations in the Chinese and Western patients with intrahepatic cholangiocarcinoma.

BACKGROUND: The goal of this study is to disclose the clinically significant genomic alterations in the Chinese and Western patients with intrahepatic cholangiocarcinoma. METHODS: A total of 86 Chinese patients were enrolled in this study. A panel of 579 pan-cancer genes was sequenced for the qualified samples from these patients. Driver genes, actionability, and tumor mutational burden were inferred and compared to a cohort of Western patients. RESULTS: Totally, 36 and 12 driver genes were identified in the Chinese and Western cohorts, respectively. Of them, seven driver genes (IDH1, KRAS, TP53, BAP1, PBRM1, ARID1A, and NRAS) were shared by the two cohorts. Four driver genes (SPTA1, ARID2, TP53, and GATA1) were found significantly correlated with the tumor mutational burden. For both cohorts, half of the patients had actionable mutations. The two cohorts shared the most actionable genes but differed much in their frequency. Though KRAS mutations were at the first and second actionable rank respectively for the Chinese and Western populations, they were still at a relatively low level of actionable evidence. CONCLUSIONS: The study on the clinical significance of genomic alterations directs the future development of precision medicine for intrahepatic cholangiocarcinoma treatment.

Long noncoding RNA linc00467 plays an oncogenic role in hepatocellular carcinoma by regulating the miR-18a-5p/NEDD9 axis.

Increasing evidence has shown that numerous long noncoding RNAs (lncRNAs) play critical roles in tumorigenesis. Herein, we investigated the biological role of lncRNA linc00467 in the cancer biology of hepatocellular carcinoma (HCC). We observed that linc00467 was upregulated in HCC tissues and cells. Silencing of linc00467 using small interfering RNA interference significantly inhibited the growth and motility of HCC cells, and increased cell apoptosis through regulating the Bcl-2/Bax axis and the caspase cascade, suggesting that linc00467 exerted oncogenic functions in the progression of HCC. Moreover, we found that linc00467 could target miR-18a-5p, and NEDD9 was a target for miR-18a-5p in HCC cells. Furthermore, either the miR-18a-5p inhibitor or upregulation of NEDD9 could recover the inhibitory effects caused by silencing of linc00467. In conclusion, our data highlighted the oncogenic role of linc00467 in HCC progression by regulating the miR-18a-5p/NEDD9 axis.

Graphene/Amorphous Carbon Restriction Structure for Stable and Long-Lifespan Antimony Anode in Potassium-Ion Batteries.

Sb-based materials have attracted much attention owing to their ability to undergo a multi-electron alloy reaction with K+ . However, there are still the serious problems of volume change and aggregation of particles, which lead to rapid capacity fading and a limited lifespan. In this work, a graphene/amorphous carbon restriction structure is proposed, in which the amorphous carbon layer on the surface of Sb nanoparticles can protect the particles from pulverization, and the graphene can buffer the volume change of the material. In addition, the conductive network formed by the dual carbon structure effectively improves the rate performance of the material. Thus, the material delivers a high capacity of 550 mA h g-1 at 100 mA g-1 , a rate capability of 370 mA h g-1 at 2000 mA g-1 , and a long lifespan of 350 cycles without significant capacity fading. The dual carbon strategy proposed offers a reference for the design of high-performance anode materials.

A kinetics study on intercalation pseudocapacitance of layered TiS2 in K-ion batteries.

The boundary between a capacitor and a battery is vague for layered transition metal sulfides, especially when it comes to TiS2 with a multi-phase transition process. In this work we analyzed both the quasi-static process and dynamic process of K+ storage in TiS2 with carbonate based electrolytes, which proved to be an intercalation pseudocapacitive behavior.

RBBP6 increases radioresistance and serves as a therapeutic target for preoperative radiotherapy in colorectal cancer.

Radiotherapy (RT) can be used as preoperative treatment to downstage initially unresectable locally rectal carcinoma, but radioresistance and recurrence remain significant problems. Retinoblastoma binding protein 6 (RBBP6) has been implicated in the regulation of cell cycle, apoptosis and chemoresistance both in vitro and in vivo. The present study investigated whether the inhibition of RBBP6 expression would improve radiosensitivity in human colorectal cancer cells. After SW620 and HT29 cells were exposed to radiation, the levels of RBBP6 mRNA and protein increased over time in both cells. Moreover, a significant reduction in clonogenic survival and a decrease in cell viability in parallel with an obvious increase in cell apoptosis were demonstrated in irradiated RBBP6-knockdown cells. Transfection with RBBP6 shRNA improved the levels of G2-M phase arrest, which blocked the cells in a more radiosensitive period of the cell cycle. These observations indicated that cell cycle and apoptosis mechanisms may be connected with tumor cell survival following radiotherapy. In vivo, the tumor growth rate of nude mice in the RBBP6-knockdown group was significantly slower than that in other groups. These results indicated that RBBP6 overexpression could resist colorectal cancer cells against radiation by regulating cell cycle and apoptosis pathways, and inhibition of RBBP6 could enhance radiosensitivity of human colorectal cancer.

Diagnostic and therapeutic strategies to manage post-pancreaticoduodenectomy hemorrhage.

OBJECTIVE: To explore the causes, diagnosis and treatment of post-pancreaticoduodenectomy hemorrhages (PPHs). METHODS: A database of 703 pancreaticoduodenectomy patients in our institution (January 2008-July 2013) was analyzed retrospectively. RESULTS: PPHs occurred in 62 patients of which, 38 had clear causes and 15 died because of uncontrolled bleeding and multiple organ failure. Pancreatic fistula and abdominal infection rates were significantly higher in the PPH group compared to the group who did not experience hemorrhages (P < 0.05) but did not significantly increase the mortality of PPH patients. Hemostasis was attempted by endotherapy in 7 patients and was successful in 4 (57.1 %). Angioembolization was performed in 12 patients and was successful in 10 (83.3 %) and relaparotomy in 24 patients successful in 13 (54.2 %). All deceased patients belonged to International Study Group of Pancreatic Surgery clinical grade C and sentinel bleeding occurred in 60 % of PPH mortalities (9/15) (P = 0.005). CONCLUSION: Pancreatic fistulae and abdominal infections are associated with PPH. Control of early mild upper gastrointestinal hemorrhages could be attempted by endotherapy, but angiography with intervention or surgical treatments were always required for delayed bleeding. The mortality in cases with sentinel bleedings was obviously increased.

Demonstration of the route of embryo migration in retroperitoneal ectopic pregnancy using contrast-enhanced computed tomography.

Retroperitoneal abdominal pregnancy is exceptionally rare. An unusual retroperitoneal pregnancy has a high risk of severe bleeding. Abdominal ultrasonography and whole abdominal computerized tomography scanning should be performed for the early diagnosis of ectopic pregnancy. A case of retroperitoneal ectopic pregnancy located very close to large retroperitoneal blood vessels and treated with resection is presented. Many unusual features of retroperitoneal ectopic pregnancy were highlighted as providing further evidence in support of the main proposed embryo migration mechanism via lymphatic vessels.

Self-adhesive, conductive, and multifunctional hybrid hydrogel for flexible/wearable electronics based on triboelectric and piezoresistive sensor.

Flexible electronics are highly developed nowadays in human-machine interfaces (HMI). However, challenges such as lack of flexibility, conductivity, and versatility always greatly hindered flexible electronics applications. In this work, a multifunctional hybrid hydrogel (H-hydrogel) was prepared by combining two kinds of 1D polymer chains (polyacrylamide and polydopamine) and two kinds of 2D nanosheets (Ti3C2Tx MXene and graphene oxide nanosheets) as quadruple crosslinkers. The introduced Ti3C2Tx MXene and graphene oxide nanosheets are bonded with the PAM and PDA polymer chains by hydrogen bonds. This unique crosslinking and stable structure endow the H-hydrogel with advantages such as good flexibility, electrical conductivity, self-adhesion, and mechanical robustness. The two kinds of nanosheets not only improved the mechanical strength and conductivity of the H-hydrogel, but also helped to form the double electric layers (DELs) between the nanosheets and the bulk-free water phase inside the H-hydrogel. When utilized as the electrode of a triboelectric nanogenerator (TENG), high electrical output performances were realized due to the dynamic balance of the DELs between the nanosheets and the H-hydrogel's inside water molecules. Moreover, flexible sensors, including triboelectric, and strain/pressure sensors, were achieved for human motion detection at low frequencies. This hydrogel is promising for HMI and e-skin.

Development and validation of a gene expression-based nomogram to predict the prognosis of patients with cholangiocarcinoma.

AIM: To establish and validate a prognostic nomogram of cholangiocarcinoma (CCA) using independent clinicopathological and genetic mutation factors. METHODS: 213 patients with CCA (training cohort n = 151, validation cohort n = 62) diagnosed from 2012 to 2018 were included from multi-centers. Deep sequencing targeting 450 cancer genes was performed. Independent prognostic factors were selected by univariate and multivariate Cox analyses. The clinicopathological factors combined with (A)/without (B) the gene risk were used to establish nomograms for predicting overall survival (OS). The discriminative ability and calibration of the nomograms were assessed using C-index values, integrated discrimination improvement (IDI), decision curve analysis (DCA), and calibration plots. RESULTS: The clinical baseline information and gene mutations in the training and validation cohorts were similar. SMAD4, BRCA2, KRAS, NF1, and TERT were found to be related with CCA prognosis. Patients were divided into low-, median-, and high-risk groups according to the gene mutation, the OS of which was 42.7 ± 2.7 ms (95% CI 37.5-48.0), 27.5 ± 2.1 ms (95% CI 23.3-31.7), and 19.8 ± 4.0 ms (95% CI 11.8-27.8) (p < 0.001), respectively. The systemic chemotherapy improved the OS in high and median risk groups, but not in the low-risk group. The C-indexes of the nomogram A and B were 0.779 (95% CI 0.693-0.865) and 0.725 (95% CI 0.619-0.831), p < 0.01, respectively. The IDI was 0.079. The DCA showed a good performance and the prognostic accuracy was validated in the external cohort. CONCLUSION: Gene risk has the potential to guide treatment decision for patients at different risks. The nomogram combined with gene risk showed a better accuracy in predicting OS of CCA than not.

DEPDC1B promotes development of cholangiocarcinoma through enhancing the stability of CDK1 and regulating malignant phenotypes.

Cholangiocarcinoma (CCA) is the second most common primary tumor of the hepatobiliary system. At present, the therapeutic efficiency of cholangiocarcinoma is fairly low and the prognosis is poor. The root cause is that the molecular mechanism of the occurrence and development of CCA is largely unclear. This work intended to clarify the role of DEP domain-containing protein 1B (DEPDC1B) in the progress of CCA through cellular biology research strategies and further clarify the molecular mechanism of CCA. Clinical tissue-related detection showed that the expression level of DEPDC1B in tumor tissues was significantly higher than that in normal tissues and was positively correlated with tumor grade. Knockdown of the endogenous DEPDC1B of CCA cells can significantly inhibit cell proliferation and migration, while promoting cell apoptosis and blocking the cell cycle. DEPDC1B overexpression induced the opposite effects. Studies in animal models also showed that the downregulation of DEPDC1B can reduce the tumorigenicity of CCA cells. In addition, through gene profiling analysis and molecular biology studies, we found that CDK1 may be an important downstream mediator of DEPDC1B, the protein stability of which was significantly decreased through the ubiquitin-proteasome system in DEPDC1B knockdown cells. Moreover, knockdown of CDK1 can weaken the promotion of CCA caused by DEPDC1B overexpression. In summary, our research showed that DEPDC1B plays an important role in the development of CCA and its targeted inhibition may become one of the important methods to inhibit the progress of CCA.

Emission evolution of alpha-silicon nitride nanowires with temperature.

The photoluminescence and temperature dependent emission spectra of silicon nitride nanowires were investigated by using femtosecond pulse laser. Three discrete sharp emission peaks were observed in photoluminescence, which were significantly different from that pumping by low excitation intensity laser. The temperature effects on emission peak energy were extracted using Gauss function, and should be attributed to volume-temperature effect and phonon effect.

Self-Assembled Triple (H+/O2-/e-) Conducting Nanocomposite of Ba-Co-Ce-Y-O into an Electrolyte for Semiconductor Ionic Fuel Cells.

Triple (H+/O2-/e-) conducting oxides (TCOs) have been extensively investigated as the most promising cathode materials for solid oxide fuel cells (SOFCs) because of their excellent catalytic activity for oxygen reduction reaction (ORR) and fast proton transport. However, here we report a stable twin-perovskite nanocomposite Ba-Co-Ce-Y-O (BCCY) with triple conducting properties as a conducting accelerator in semiconductor ionic fuel cells (SIFCs) electrolytes. Self-assembled BCCY nanocomposite is prepared through a complexing sol-gel process. The composite consists of a cubic perovskite (Pm-3m) phase of BaCo0.9Ce0.01Y0.09O3-δ and a rhombohedral perovskite (R-3c) phase of BaCe0.78Y0.22O3-δ. A new semiconducting-ionic conducting composite electrolyte is prepared for SIFCs by the combination of BCCY and CeO2 (BCCY-CeO2). The fuel cell with the prepared electrolyte (400 µm in thickness) can deliver a remarkable peak power density of 1140 mW·cm-2 with a high open circuit voltage (OCV) of 1.15 V at 550 °C. The interface band energy alignment is employed to explain the suppression of electronic conduction in the electrolyte. The hybrid H+/O2- ions transport along the surfaces or grain boundaries is identified as a new way of ion conduction. The comprehensive analysis of the electrochemical properties indicates that BCCY can be applied in electrolyte, and has shown tremendous potential to improve ionic conductivity and electrochemical performance.

Toxic effects of hexavalent chromium (Cr6+) on bioaccumulation, apoptosis, oxidative damage and inflammatory response in Channa asiatica.

The objective of this study was to evaluate the toxic effects of Cr6+ on bioaccumulation, digestion, immunity, oxidative stress, apoptosis and inflammation-related genes in Channa asiatica. The fish was exposed to waterborne Cr6+ concentrations (0, 0.5, 1.0 and 2.0 mg/L) for 28 and 56 days. Our results demonstrated that the accumulation of Cr6+ in tissues increased in a concentration-dependent manner, and the content in tissue was liver > gill > gut > muscle. Meanwhile, Cr6+ exposure led to a remarkable suppression of digestion, immunity and antioxidant capacity in C. asiatica. Inversely, MDA and PC content were positively correlated with Cr6+ exposure concentration. Furthermore, the expression of genes went up with the increase of waterborne Cr6+ concentration. Among them, HSP90, NF-κB and TNF-α have a sharp increase. These results elucidate that waterborne Cr6+ exposure may induce bioaccumulation, inhibit digestion and immunity, promote oxidative stress and up-regulate the expression of apoptosis and inflammation-related genes in C. asiatica.

miR-4709-3p Inhibits Cell Proliferation by Downregulating TSP50 Expression in Breast Cancer Cells.

Breast cancer is a serious threat to the physical and mental health of women all over the world. Our previous results have shown that Serine protease 50 (TSP50), an oncogene overexpressed in breast cancer, can promote proliferation, migration, and invasion of breast cancer cells. Mechanistic studies have revealed that TSP50 promoted tumorigenesis mainly by activating NF-kappa B (NF-κB) and inhibiting activin signaling pathway, indicating that TSP50 played a critical role in the occurrence and development of breast cancer. However, there are few reports on the regulation of TSP50 expression in breast cancer. MicroRNAs (miRNAs) have emerged as an essential posttranscriptional regulator in gene expression and they played a significant role in breast cancer regulation. In the present study, bioinformatics software miRBase and TargetScan were first used to predict and analyze miRNAs that could target TSP50 mRNA 3'UTR and six miRNAs were found. Results from quantitative real-time PCR (qRT-PCR) and western blot suggested that miR-4709-3p could bind to TSP50 mRNA 3'UTR and significantly inhibit the expression of TSP50 protein. Moreover, the effects of miR-4709-3p on the proliferation of breast cancer cells and mammary epithelial cells were detected in vitro. Our data suggested that overexpression of miR-4709-3p mimic greatly inhibited the proliferation of breast cancer cells, whereas overexpression of miR-4709-3p inhibitors significantly promoted the proliferation of breast epithelial cells. Furthermore, the effect of miR-4709-3p on the tumorigenicity of breast cancer cells in vivo was tested, and the results showed that miR-4709-3p significantly reduced the volume and weight of tumor in nude mice. All these results suggested that miR-4709-3p could inhibit the tumorigenesis of breast cancer cells by targeting TSP50. Finally, the underlying molecular mechanisms were investigated and we found that both NF-κB and activin signaling were involved in miR-4709-3p-related tumor inhibitory effect.

Specific genomic alterations and prognostic analysis of perihilar cholangiocarcinoma and distal cholangiocarcinoma.

BACKGROUND: Cholangiocarcinoma (CCA), which consists of intrahepatic CCA (iCCA), perihilar CCA (pCCA), and distal CCA (dCCA), is an aggressive malignancy worldwide. PCCA and dCCA are often classified as extrahepatic CCA (exCCA). However, the differences in mutational characteristics between pCCA and dCCA remain unclear. METHODS: Deep sequencing targeting of 450 cancer genes was performed for genomic alteration detection. The tumor mutational burden (TMB) was measured by an algorithm developed in-house. Correlation analysis was conducted using Fisher's exact test. RESULTS: FGFR2 and ERBB2 mutations mainly occurred in iCCA and exCCA, respectively. In exCCA, the frequencies of PIK3CA, FAT4, KDM6A, MDM2, and TCF7L2 mutations were significantly higher in pCCA compared to dCCA, while the frequencies of TP53 and KRAS mutations were markedly lower in pCCA than those in dCCA. The prognosis-related mutations were different among the CCA subtypes. NF1 mutation was associated with short disease-free survival (DFS) and overall survival (OS), and ERBB2 mutation was associated with short DFS in dCCA patients. Meanwhile, MAP2K4 mutation was associated with long DFS and OS, and TERT mutation was associated with short DFS in pCCA. A series of mutations in genes, including ARID1A, ARID2, SMAD4, TERT, TP53, and KRAS, were found to be associated with the TMB. CONCLUSIONS: In this study, we investigated the comprehensive genomic characterizations of CCA patients, identified the significant alterations in each subtype, and identified potential biomarkers for prognosis prediction. These results provide molecular evidence for the heterogeneity of CCA subtypes and evidence for further precision targeted therapy of CCA patients.

Hepatitis B virus X protein upregulates transcriptional activation of human telomerase reverse transcriptase.

It is well known that telomerase activation and virus infection are strongly associated with human hepatocellular carcinoma (HCC). Hepatitis B virus X protein (HBx) plays an important role in HCC pathogenesis. However, the mechanisms of HBx on telomerase activity are not well understood. To determine the potential roles of HBx in telomerase activity, both transfection and antisense assay were designed to examine the effects of HBx on telomerase in this report. Results showed that HBX gene increased telomerase activity and human telomerase reverse transcriptase (hTERT) expression in HBx-transfected cells and HBx-positive HCC samples. Co-transfection and luciferase reporter assay showed that HBx could stimulate hTERT promoter in a dose-dependent manner in different cells. Truncated and mutant reporter assays revealed that Sp1 binding sites mapped at -132 to +5 nt in hTERT promote were important for HBx-mediated upregulation of hTERT. Western blot did not show any change of Sp1 expression in HBx-transfected cells, but EMSA showed evidence of that HBx increased binding of Sp1 to its target DNA. These results provide new insights into the role of HBx in liver carcinogenesis.