Transcriptomic Analysis of Mycobacterial Infected Macrophages Reveals a High MOI Specific Type I IFN Signaling.

Macrophage (MΦ) infection models are important tools for studying host-mycobacterial interactions. Although the multiplicity of infection (MOI) is an important experimental variable, the selection of MOI in mycobacterial infection experiments is largely empirical, without reference to solid experimental data. To provide relevant data, we used RNA-seq to analyze the gene expression profiles of MΦs 4 or 24 h after infection with Mycobacterium marinum (M. m) at MOIs ranging from 0.1 to 50. Analysis of differentially expressed genes (DEGs) showed that different MOIs are linked to distinct transcriptomic changes and only 10% of DEGs were shared by MΦ infected at all MOIs. KEGG pathway enrichment analysis revealed that type I interferon (IFN)-related pathways were inoculant dose-dependent and enriched only at high MOIs, whereas TNF pathways were inoculant dose-independent and enriched at all MOIs. Protein-protein interaction (PPI) network alignment showed that different MOIs had distinct key node genes. By fluorescence-activated cell sorting and follow-up RT-PCR analysis, we could separate infected MΦs from uninfected MΦs and found phagocytosis of mycobacteria to be the determinant factor for type I IFN production. The distinct transcriptional regulation of RAW264.7 MΦ genes at different MOIs was also seen with Mycobacterium tuberculosis (M.tb) infections and primary MΦ infection models. In summary, transcriptional profiling of mycobacterial infected MΦs revealed that different MOIs activate distinct immune pathways and the type I IFN pathway is activated only at high MOIs. This study should provide guidance for selecting the MOI most appropriate for different research questions.

Predictors of Long-Term Rebleeding Risk in Cirrhotic Patients Undergoing Esophagogastric Devascularization and Splenectomy: Impact of Portal Vein Thrombosis and Hemoglobin Levels.

BACKGROUND Esophagogastric devascularization and splenectomy (EGDS) is widely used to treat patients with portal hypertension in China. This study aimed to determine risk factors that increase risk of rebleeding after EGDS and evaluate the effect of portal vein thrombosis (PVT) on rebleeding rates after EGDS. MATERIAL AND METHODS Clinical data of patients with cirrhosis (n=138) who underwent EGDS between December 2010 and January 2016 were retrospectively analyzed. Patients were assigned to rebleeding or non-rebleeding groups and followed up. Univariate and multivariate Cox regression analyses identified the independent predictors of 3-year and 5-year rebleeding. RESULTS A total of 138 consecutive patients who underwent EGDS and met the inclusion criteria were enrolled. Total bilirubin (HR: 2.392, 95% CI 1.032-5.545, P=0.042) and PVT (HR: 3.345, 95% CI 1.477-7.573, P=0.004) predicted 3-year rebleeding during univariate analysis. Multivariate analysis revealed that PVT (HR: 3.967, 95% CI 1.742-9.035, P=0.001) was an independent predictor. Hemoglobin >87.5 g/L (HR: 3.104, 95% CI 1.283-7.510, P=0.012) and PVT (HR: 2.349, 95% CI 1.231-4.483, P=0.010) were predictors of 5-year rebleeding during multivariate analysis. Albumin >37.5 g/L was an independent predictor of rebleeding in patients with PVT at 3 and 5 years (HR: 3.964, 95% CI 1.301-9.883, P=0.008; HR: 3.193, 95% CI 1.275-7.997, P=0.013, respectively). CONCLUSIONS PVT is associated with increased 3-year and 5-year rebleeding rates after EGDS but not at 10 years. Also, hemoglobin >87.5 g/L predicted rebleeding at 5 years. Albumin has huge prospects as a predictor of rebleeding at 3 and 5 years in patients with PVT.

Drug Degradation Caused by mce3R Mutations Confers Contezolid (MRX-I) Resistance in Mycobacterium tuberculosis.

Contezolid (MRX-I), a safer antibiotic of the oxazolidinone class, is a promising new antibiotic with potent activity against Mycobacterium tuberculosis (MTB) both in vitro and in vivo. To identify resistance mechanisms of contezolid in MTB, we isolated several in vitro spontaneous contezolid-resistant MTB mutants, which exhibited 16-fold increases in the MIC of contezolid compared with the parent strain but were still unexpectedly susceptible to linezolid. Whole-genome sequencing revealed that most of the contezolid-resistant mutants bore mutations in the mce3R gene, which encodes a transcriptional repressor. The mutations in mce3R led to markedly increased expression of a monooxygenase encoding gene Rv1936. We then characterized Rv1936 as a putative flavin-dependent monooxygenase that catalyzes the degradation of contezolid into its inactive 2,3-dihydropyridin-4-one (DHPO) ring-opened metabolites, thereby conferring drug resistance. While contezolid is an attractive drug candidate with potent antimycobacterial activity and low toxicity, the occurrence of mutations in Mce3R should be considered when designing combination therapy using contezolid for treating tuberculosis.

Spencerozyma acididurans sp. nov., an acid-tolerant basidiomycetous yeast species isolated from acid mine drainage.

Strain SYSU-17, representing a novel acid-tolerant yeast species which can grow at pH 2.0 weakly, was isolated from acid mine drainage collected in a tailing impoundment of the Fankou Lead/Zinc Mine, Guangdong Province, PR China. Phylogenetic analysis of strain SYSU-17 based on the internal transcribed spacer (ITS) region and the D1/D2 domains of the large subunit ribosomal RNA (LSU rRNA) gene suggested that strain SYSU-17 was a novel species belonging to the genus Spencerozyma (class Microbotryomycetes, subphylum Pucciniomycotina). It differed from the type strain of the closest related species, Spencerozyma crocea CBS 2029T, by 0.7 % sequence divergence (three gaps and one nucleotide substitution out of 594 bp) in the D1/D2 domains of the LSU rRNA gene and 7.6 % sequence divergence (32 gaps and 22 nucleotide substitutions out of 714 bp) in the ITS region. In contrast to the physiological properties of S. crocea, the novel yeast species was unable to assimilate galactose, d-ribose, xylitol, succinate, d-xylose, ethanol, nitrate and nitrite. The name Spencerozyma acididurans sp. nov. is proposed and SYSU-17 is designated as the holotype.

Genetically encoded transcriptional plasticity underlies stress adaptation in Mycobacterium tuberculosis.

Transcriptional regulation is a critical adaptive mechanism that allows bacteria to respond to changing environments, yet the concept of transcriptional plasticity (TP) - the variability of gene expression in response to environmental changes - remains largely unexplored. In this study, we investigate the genome-wide TP profiles of Mycobacterium tuberculosis (Mtb) genes by analyzing 894 RNA sequencing samples derived from 73 different environmental conditions. Our data reveal that Mtb genes exhibit significant TP variation that correlates with gene function and gene essentiality. We also find that critical genetic features, such as gene length, GC content, and operon size independently impose constraints on TP, beyond trans-regulation. By extending our analysis to include two other Mycobacterium species -- M. smegmatis and M. abscessus -- we demonstrate a striking conservation of the TP landscape. This study provides a comprehensive understanding of the TP exhibited by mycobacteria genes, shedding light on this significant, yet understudied, genetic feature encoded in bacterial genomes.

Mycobacterial CpsA activates type I IFN signaling in macrophages via cGAS-mediated pathway.

Type I interferon (IFN) production is crucial in tuberculosis pathogenesis, yet the bacterial factors initiating this process are incompletely understood. CpsA, protein of Mycobacterium marinum and Mycobacterium tuberculosis, plays a key role in maintaining bacterial virulence and inhibiting host cell LC3-associated phagocytosis. By utilizing CpsA full deletion mutant studies, we re-verified its essential role in infection-induced pathology and revealed its new role in type I IFN expression. CpsA deficiency hindered IFN production in infected macrophages in vitro as well as zebrafish and mice in vivo. This effect was linked to the cGAS-TBK1-IRF3 pathway, as evidenced by decreased TBK1 and IRF3 phosphorylation in CpsA-deficient bacterial strain-infected macrophages. Moreover, we further show that CpsA deficiency cause decreased cytosolic DNA levels, correlating with impaired phagosomal membrane rupture. Our findings reveal a new function of mycobacterial CpsA in type I IFN production and offer insight into the molecular mechanisms underlying mycobacterial infection pathology.

Drainage by urostomy bag after blockage of abdominal drain in patients with cirrhosis undergoing hepatectomy.

Abdominal drainage was previously recommended as a post-hepatectomy procedure for patients with cirrhosis. This report introduces a simple technique that prevents leakage of ascitic fluid after cirrhotic hepatectomy complicated by blockage of the abdominal drain. In 59 patients who had had cirrhotic hepatectomy complicated by leakage of ascites in the drain site after drainage removal between January 2001 and April 2011, 31 underwent suture ligation (sutured group) and 28 were given urostomy bag at the abdominal drainage site (drainage group). The mean length of postoperative hospital stay in the drainage group was shorter than in the sutured group (16.11+/-2.61 vs 34.23+/-4.86 days, P=0.000). Meanwhile, the drainage group showed decreased postoperative complications, including leakage of ascites, wound infection, and collection of ascites. Drainage by urostomy bag can prevent prolonged leakage of ascitic fluid after the blockage of abdominal drains in patients undergoing cirrhotic hepatectomy.

[Analysis on preparation and characterization of asiaticoside-loaded flexible nanoliposomes].

Asiaticoside is a compound extracted from traditional Chinese medicine Centella asiatica, and mainly used in wound healing and scar repair in clinical, with notable efficacy. However, its poor transdermal absorption and short action time restrict its wide application. In this experiment, the reserve-phase-extrusion-lyophilization method was conducted to prepare the lyophilized asiaticoside-loaded flexible nanoliposomes (LAFL). Its characteristics including electron microscope structure, particle size, Zeta potential, entrapment rate, drug-loading rate, stability and drug release were determined with the intelligent transdermal absorption instrument. LAFL were white spheroids, with pH, particle size and zeta potential of 7. 03, 70. 14 nm and - 36. 5 mV, respectively. The average entrapment rate of the 3 batch samples were 31. 43% , and the average asiaticoside content in 1 mg lyophilized simple was 0. 134 mg. The results indicated that LAFL have good physicochemical properties and pharmaceutical characteristics, with an improved transdermal performance.

In vivo RNA interactome profiling reveals 3'UTR-processed small RNA targeting a central regulatory hub.

Small noncoding RNAs (sRNAs) are crucial regulators of gene expression in bacteria. Acting in concert with major RNA chaperones such as Hfq or ProQ, sRNAs base-pair with multiple target mRNAs and form large RNA-RNA interaction networks. To systematically investigate the RNA-RNA interactome in living cells, we have developed a streamlined in vivo approach iRIL-seq (intracellular RIL-seq). This generic approach is highly robust, illustrating the dynamic sRNA interactomes in Salmonella enterica across multiple stages of growth. We have identified the OmpD porin mRNA as a central regulatory hub that is targeted by a dozen sRNAs, including FadZ cleaved from the conserved 3'UTR of fadBA mRNA. Both ompD and FadZ are activated by CRP, constituting a type I incoherent feed-forward loop in the fatty acid metabolism pathway. Altogether, we have established an approach to profile RNA-RNA interactomes in live cells, highlighting the complexity of RNA regulatory hubs and RNA networks.

Genetically encoded transcriptional plasticity underlies stress adaptation in Mycobacterium tuberculosis.

Transcriptional regulation is a critical adaptive mechanism that allows bacteria to respond to changing environments, yet the concept of transcriptional plasticity (TP) remains largely unexplored. In this study, we investigate the genome-wide TP profiles of Mycobacterium tuberculosis (Mtb) genes by analyzing 894 RNA sequencing samples derived from 73 different environmental conditions. Our data reveal that Mtb genes exhibit significant TP variation that correlates with gene function and gene essentiality. We also found that critical genetic features, such as gene length, GC content, and operon size independently impose constraints on TP, beyond trans-regulation. By extending our analysis to include two other Mycobacterium species -- M. smegmatis and M. abscessus -- we demonstrate a striking conservation of the TP landscape. This study provides a comprehensive understanding of the TP exhibited by mycobacteria genes, shedding light on this significant, yet understudied, genetic feature encoded in bacterial genomes.

Genetically encoded transcriptional plasticity underlies stress adaptation in Mycobacterium tuberculosis.

Transcriptional regulation is a critical adaptive mechanism that allows bacteria to respond to changing environments, yet the concept of transcriptional plasticity (TP) remains largely unexplored. In this study, we investigate the genome-wide TP profiles of Mycobacterium tuberculosis (Mtb) genes by analyzing 894 RNA sequencing samples derived from 73 different environmental conditions. Our data reveal that Mtb genes exhibit significant TP variation that correlates with gene function and gene essentiality. We also found that critical genetic features, such as gene length, GC content, and operon size independently impose constraints on TP, beyond trans-regulation. By extending our analysis to include two other Mycobacterium species -- M. smegmatis and M. abscessus -- we demonstrate a striking conservation of the TP landscape. This study provides a comprehensive understanding of the TP exhibited by mycobacteria genes, shedding light on this significant, yet understudied, genetic feature encoded in bacterial genomes.

Inhibition of GSK-3beta ameliorates hepatic ischemia-reperfusion injury through GSK-3beta/beta-catenin signaling pathway in mice.

BACKGROUND: Glycogen synthase kinase (GSK)-3beta/beta-catenin signaling regulates ischemia-reperfusion (I/R)-induced apoptosis and proliferation, and inhibition of GSK-3beta has beneficial effects on I/R injury in the heart and the central nervous system. However, the role of this signaling in hepatic I/R injury remains unclear. The present study aimed to investigate the effects and mechanism of GSK-3beta/beta-catenin signaling in hepatic I/R injury. METHODS: Male C57BL/6 mice (weighing 22-25 g) were pretreated with either SB216763, an inhibitor of GSK-3beta, or vehicle. These mice were subjected to partial hepatic I/R. Blood was collected for test of alanine aminotransferase (ALT), and liver specimen for assays of phosphorylation at the Ser9 residue of GSK-3beta, GSK-3beta activity, axin 2 and the anti-apoptotic factors Bcl-2 and survivin, as well as the proliferative factors cyclin D1 and proliferating cell nuclear antigen, and apoptotic index (TUNEL). Real-time PCR, Western blotting and immunohistochemical staining were used. RESULTS: SB216763 increased phospho-GSK-3beta levels and suppressed GSK-3beta activity (1880+/-229 vs 3280+/-272 cpm, P<0.01). ALT peaked at 6 hours after reperfusion. Compared with control, SB216763 decreased ALT after 6 hours of reperfusion (4451+/-424 vs 7868+/-845 IU/L, P<0.01), and alleviated hepatocyte necrosis and vacuolization. GSK-3beta inhibition led to the accumulation of beta-catenin in the cytosol (0.40+/-0.05 vs 1.31+/-0.11, P<0.05) and nucleus (0.62+/-0.14 vs 1.73+/-0.12, P<0.05), beta-catenin further upregulated the expression of axin 2. Upregulation of GSK-3beta/beta-catenin signaling increased Bcl-2, survivin and cyclin D1. Serological and histological analyses showed that SB216763 alleviated hepatic I/R-induced injury by reducing apoptosis (1.4+/-0.2% vs 3.6+/-0.4%, P<0.05) and enhanced liver proliferation (56+/-8% vs 19+/-4%, P<0.05). CONCLUSION: Inhibition of GSK-3beta ameliorates hepatic I/R injury through the GSK-3beta/beta-catenin signaling pathway.

Nano-hydroxyapatite/ß-tricalcium phosphate ceramics scaffolds loaded with cationic liposomal ceftazidime: preparation, release characteristics in vitro and inhibition to Staphylococcus aureus biofilms.

In the current study, nano-hydroxyapatite/ß-tricalcium phosphate (HA/ß-TCP) ceramics scaffolds loaded with cationic liposomal ceftazidime (CLCs) prepared by modified reverse phase evaporation method, the investigations of their release characteristics were performed by the dissolution tests, in vitro anti-biofilm activity of the scaffolds was studied by the determination of bacterial susceptibility with ELISA. The mean particle size, zeta potential, pH and entrapment efficiency of the CLCs studied were 161.5 ± 5.37 nm, 60.60 ± 5.24 mV, 6.90 ± 0.07 and 16.57 ± 0.13%, respectively. Electron microscopic images of the samples indicated that the liposomes were well preserved in the scaffolds and that it was the CLCs rather than free ceftazidime releasing from the scaffolds. The minimal inhibitory concentrations (MICs) to Staphylococcus aureus of free ceftazidime and its liposomal formulation were 6.00 µg/mL and the release behaviors of both CLCs and free ceftazidime from scaffolds were based on the dissolution/diffusion processes, Fick's law. These results demonstrated that CLCs could inhibit remarkably the formation of S. aureus biofilm more effectively than free ceftazidime (P < 0.05). The study demonstrated that the HA/ß-TCP ceramic scaffolds was such a material that could sustain release CLCs and maintain the adequate amounts of CLCs to absorb to biofilm. It provided an ideal way to inhibit bacterial biofilms for clinical practices.

Modern Beijing sublineage of Mycobacterium tuberculosis shift macrophage into a hyperinflammatory status.

The high prevalence of the modern Beijing sublineage of Mycobacterium tuberculosis may be related to increased virulence, although the responsible mechanisms remain poorly understood. We previously described enhanced triacylglycerol accumulation in modern Beijing strains. Here we show that modern Beijing strains grow faster in vitro and trigger a vigorous immune response and pronounced macrophage infiltration. Transcriptomic analysis of bone marrow derived macrophages infected with modern Beijing lineage strains revealed a significant enrichment of infection, cholesterol homeostasis and amino acid metabolic pathways. The upregulation of proinflammatory / bactericidal cytokines was confirmed by RT-PCR analysis, which is also in consistent with the reduced bacterial burden in modern strains infected macrophages. These results suggest that modern Beijing strains elicit a hyperinflammatory response which might indicate a stronger virulence and contribute to their extensive global prevalence.

Microvesicles: the functional mediators in sorafenib resistance.

Overcoming drug resistance in cancer therapies remains challenging, and the tumor microenvironment plays an important part in it. Microvesicles (MVs) are functional natural carriers of cellular information, participate in intercellular communication, and dynamically regulate the tumor microenvironment. They contribute to drug resistance by transferring functional molecules between cells. Conversely, due to their specific cell or tissue targeting ability, MVs are considered as carriers for therapeutic molecules to reverse drug resistance. Thus, in this mini-review, we aim to highlight the crucial role of MVs in cell-to-cell communication and therefore their diverse impact mainly on liver cancer progression and treatment. In addition, we summarize the possible mechanisms for sorafenib resistance (one of the main hurdles in hepatocellular carcinoma treatments) and recent advances in using MVs to reverse sorafenib resistance in liver cancer therapies. Identifying the functional role of MVs in cancer therapy might provide a new aspect for developing precise novel therapeutics in the future.

De novo phyllodes tumor in an adolescent female after liver transplantation.

Phyllodes tumor of the breast is a rare disease constituting 0.3-0.9% of all breast neoplasms. Occurring mainly in females aged 35 to 55 yr, the disease is especially rare among adolescent females. There is no published literature about de novo phyllodes tumor after liver transplantation. Here we describe a case of de novo phyllodes tumors in an adolescent female after liver transplantation from a living donor for Wilson disease.

[Protective functions of recombinant protein targeted at RANKL against hepatic ischemia/reperfusion injury transfected by retrovirus in mice].

OBJECTIVE: To explore the protective functions of recombinant protein RANK-Fc against hepatic ischemia/reperfusion injury and clarify its possible mechanism. METHODS: Sixty male Balb/c mice were randomly divided into 3 groups according to different treatments: serum-free medium control (Sham) group, target gene retrovirus (RANK-Fc) group and empty vector retrovirus (eGFP) group. All mice were injected with 2.5 ml solution (with or without retrovirus) within 6 seconds via tail vein. After 3 days, the model of 70% hepatic ischemia/reperfusion was induced under warm conditions for 90 minutes after different periods of reperfusion in RANK-Fc and eGFP groups; Sham group underwent the same procedure without the occlusion of blood supply. Blood and liver samples were obtained at different time points (1, 3, 6 and 24 h; n = 5 in each). Reverse transcription-polymerase chain reaction (RT-PCR) was used for the evaluation of eGFP mRNA expression. RANK-Fc was assessed by Western blot. Liver transaminases and histopathological changes were used for the evaluation of hepatic injury. The activity of NF-κB in liver nucleus was analyzed by Western blot and immunohistochemistry. The activation level of JNK was also assessed by Western blot. Liver homogenate levels of tumor necrosis factor (TNF)-α and interleukin (IL)-6 were detected by enzyme-linked immunosorbent assay (ELISA). Apoptosis was identified by the terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) analysis. The differences between three treatment groups at each time point were detected by the one-way ANOVA. Statistical analysis for inter-comparison was performed by Student's t test. RESULTS: RANK-Fc and eGFP were successfully expressed in liver after hydrodynamics-based transfection. Compared with eGFP group, RANK-Fc significantly improved liver functions at the same time point (P < 0.01), decreased NF-κB nuclear translocation (t = 6.726, P < 0.01)and JNK phosphorylation (t = 6.713, P < 0.01)and obviously suppressed the release of pro-inflammatory cytokine TNF-α (t = 4.779, P < 0.01) and IL-6 (t = 5.482, P < 0.01). Morphological injuries were markedly alleviated while the expressions of immunohistochemical positive cells and TUNEL staining positive cells decreased in RANF-Fc group. CONCLUSION: RANK-Fc has protective functions against hepatic ischemia/reperfusion injury in mice. Its mechanism is at least partially related with the suppressions of proinflammatory NF-κB and proapoptotic JNK signaling pathways.

A radiomics-based model on non-contrast CT for predicting cirrhosis: make the most of image data.

BACKGROUND: To establish and validate a radiomics-based model for predicting liver cirrhosis in patients with hepatitis B virus (HBV) by using non-contrast computed tomography (CT). METHODS: This retrospective study developed a radiomics-based model in a training cohort of 144 HBV-infected patients. Radiomic features were extracted from abdominal non-contrast CT scans. Features selection was performed with the least absolute shrinkage and operator (LASSO) method based on highly reproducible features. Support vector machine (SVM) was adopted to build a radiomics signature. Multivariate logistic regression analysis was used to establish a radiomics-based nomogram that integrated radiomics signature and other independent clinical predictors. Performance of models was evaluated through discrimination ability, calibration and clinical benefits. An internal validation was conducted in 150 consecutive patients. RESULTS: The radiomics signature comprised 25 cirrhosis-related features and showed significant differences between cirrhosis and non-cirrhosis cohorts (P < 0.001). A radiomics-based nomogram that integrates radiomics signature, alanine transaminase, aspartate aminotransferase, globulin and international normalized ratio showed great calibration and discrimination ability in the training cohort (area under the curve [AUC]: 0.915) and the validation cohort (AUC: 0.872). Decision curve analysis confirmed the most clinical benefits can be provided by the nomogram compared with other methods. CONCLUSIONS: Our developed radiomics-based nomogram can successfully diagnose the status of cirrhosis in HBV-infected patients, that may help clinical decision-making.

Study of the insulin signaling pathways in the regulation of ACAT1 expression in cultured macrophages.

OBJECTIVE: To determine the signaling pathways and components involved in insulin-mediated regulation of Acyl-CoA: cholesterol acyltransferase1 (ACAT1). METHODS: THP-1 cells were cultured in RPMI 1640 medium and were induced into macrophages in the presence of 160 nM phorbol 12-myristate 13-acetate (PMA). Before insulin was added in, macrophages were preincubated with the inhibitors of the insulin signaling pathway, including wortmannin, phosphatidylinositol 3-kinase (PI3K) inhibitor; PD98059, extracellular signal-regulated kinase (ERK) inhibitor; SB203580, p38 mitogen-activated protein kinase (p38MAPK) inhibitor; SP600125, c-Jun N-terminal kinase (JNK) inhibitor and U73122, phospholipase C-gamma (PLC-gamma) inhibitor. ACAT1 mRNA and protein expression level in macrophages were determined by real-time quantitative polymerase chain reaction and western blotting, respectively. RESULTS: Real-time quantitative polymerase chain reaction and western blotting demonstrated that PD98059, SB203580 or SP600125 down-regulated the expression of ACAT1 in a dose-dependent manner. However, no obvious alteration was found in wortmannin and U73122 groups. CONCLUSION: These results suggest that the ERK, p38MAPK and JNK signaling pathways may be involved in insulin-mediated regulation of ACAT1, but no PI3K and PLC-gamma signaling pathways were involved in the present study.

[Inhibitory effect of lentivirus transduced anti-telomerase siRNA therapy on hepatocellular carcinoma in nude mice].

OBJECTIVE: To study the efficacy of anti-telomerase siRNA in hepatocellular carcinoma both in vitro and in vivo. METHODS: Lentvirus vectors contained anti-telomerase siRNA were conducted with a high performance homologous recombination system, and then were transduced into human hepatocellular carcinoma HepG2 cells. The telomerase activity was detected by RT-PCR, HepG2 cell proliferation was determined by MTT assay, and apoptosis was detected by TUNEL assay. The in vivo experiment was carried out by inoculation of HepG2 cells into nude mice and the tumor growth was measured and analyzed. RESULTS: The growth of transfected HepG2 cells was significantly inhibited and the inhibition rate was 57.5% at the 8th day after transfection. The telomerase activity was significantly suppressed in vitro. The growth of transfected human hepatocellular HepG2 tumor in the nude mice was also significantly inhibited. CONCLUSION: The results of this study demonstrate that the growth of hepatocellular carcinoma cells is effectively inhibited by transfection of anti-telomerase siRNA both in vitro and in vivo.