Development and characterization of a replicon-based phenotypic assay for assessing HCV NS4B from clinical isolates

The hepatitis C virus (HCV) NS4B inhibitors have shown potent inhibition of HCV replication in vitro. To assess the effect of viral diversity on the susceptibility to NS4B inhibitors, genotype (GT)-specific GT1a and GT1b replicon shuttle vectors were designed and created for cloning HCV NS4B genes from clinical isolates. For the GT1b NS4B shuttle vector, the S2204I adaptive mutation was introduced in NS5A to improve replication due to the replacement of the K1846T adaptive mutation in NS4B with NS4B from the clinical isolates. In addition to the adaptive mutations, a newly identified Huh-7 cell line, Huh-7-1C, which is highly permissive for both GT1a and GT1b replication, was used to further enhance the replication levels. HCV NS4B gene from clinical isolates was amplified and inserted into the corresponding GT1a and GT1b modified lab strain chimeric replicons. GT1a and GT1b chimeric replicons expressing diverse NS4B genes from corresponding subtypes of clinical isolates replicated at highly efficient levels for phenotypic analysis. Due to natural variation in their amino acid residues in NS4B, these isolates displayed varying drug susceptibilities to an NS4B inhibitor. In mixed populations with wild-type, the sensitivity of resistance detection of NS4B resistant mutants H94R and V105M was between 20% and 80%. The chimeric shuttle vectors can be used to characterize the activity of antiviral drugs targeting NS4B from diverse natural clinical isolates and aid in the development of novel compounds against HCV NS4B.

Curcumin analogue T83 exhibits potent antitumor activity and induces radiosensitivity through inactivation of Jab1 in nasopharyngeal carcinoma

Background

Nasopharyngeal carcinoma (NPC) is an Epstein-Barr virus–associated malignancy that is most common in East Asia, Africa, and Alaska. Radiotherapy is the main treatment option; unfortunately, disease response to concurrent radiotherapy and chemotherapy varies among patients with NPC, and in many cases, NPC becomes resistant to radiotherapy. Our previous studies indicated that Jab1/CSN5 was overexpressed and plays a role in the pathogenesis and radiotherapy resistance in NPC. Therefore, it is important to seek for innovative therapeutics targeting Jab1/CSN5 for NPC. In this study, we explored the antitumor effect of a curcumin analogue T83 in NPC, and found T83 exhibits antitumor activity and induces radiosensitivity through inactivation of Jab1 in NPC.

Methods

NPC cell viability and proliferation were detected by the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) and colony formation assays. Cell cycle distribution was detected with use of flow cytometry. Apoptosis was examined by using the Annexin V/propidium iodide staining assay and cleavage poly(ADP-ribose polymerase (PARP) and cleavage caspase-3 expression. Jab1 expression was examined by Western blotting.

Results

A growth inhibitory effect was observed with T83 treatment in a dose- and time-dependent manner. T83 significantly induced G2/M arrest and apoptosis in NPC. In addition, T83 inhibited Jab1 expression and sensitized NPC cells to radiotherapy.

Conclusion

Our data indicate that T83 exhibits potent inhibitory activity in NPC cells and induces radiotherapy sensitivity. Thus, T83 has translational potential as a chemopreventive or therapeutic agent for NPC.

Loss of cytoplasmic KLF4 expression is correlated with the progression and poor prognosis of nasopharyngeal carcinoma

AIMS

To examine, in nasopharyngeal carcinoma (NPC), the correlation of Krüppel-like factor 4 (KLF4) expression with clinicopathological features including patient prognosis.

METHODS AND RESULTS

Using real-time PCR and immunohistochemistry, expression of KLF4 mRNA and protein was examined in NPC and nasopharyngeal tissues. The relationship of KLF4 expression levels with clinical features and prognosis of NPC patients was analysed. mRNA expression was markedly lower in NPC than in the nasopharyngeal tissues. Using immunohistochemistry, staining for KLF4 protein was found in the nuclei and cytoplasm of nasopharyngeal and malignant epithelial cells, but decreased cytoplasmic expression was observed in atypical hyperplasia and NPC samples compared to normal and squamous epithelium samples (P < 0.001). In addition, levels of cytoplasmic KLF4 protein were correlated inversely with the nodal (N) status (TNM classification; P = 0.002) and overall clinical stage (P < 0.001) of NPC patients. Patients with NPC showing lower cytoplasmic KLF4 expression had a significantly shorter overall survival time than those with high NPC KLF4 expression. Multivariate analysis suggested that the level of KLF4 expression was an independent prognostic indicator (P = 0.008) for NPC survival.

CONCLUSION

Low levels of cytoplasmic KLF4 expression are a potentially unfavourable prognostic factor for patients with NPC.

Reduced CTGF expression promotes cell growth, migration, and invasion in nasopharyngeal carcinoma

Background

The role of CTGF varies in different types of cancer. The purpose of this study is to investigate the involvement of CTGF in tumor progression and prognosis of human nasopharyngeal carcinoma (NPC).

Experimental design

CTGF expression levels were examined in NPC tissues and cells, nasopharynx (NP) tissues, and NP69 cells. The effects and molecular mechanisms of CTGF expression on cell proliferation, migration, invasion, and cell cycle were also explored.

Results

NPC cells exhibited decreased mRNA expression of CTGF compared to immortalized human nasopharyngeal epithelial cell line NP69. Similarly, CTGF was observed to be downregulated in NPC compared to normal tissues at mRNA and protein levels. Furthermore, reduced CTGF was negatively associated with the progression of NPC. Knocking down CTGF expression enhanced the colony formation, cell migration, invasion, and G1/S cell cycle transition. Mechanistic analysis revealed that CTGF suppression activated FAK/PI3K/AKT and its downstream signals regulating the cell cycle, epithelial-mesenchymal transition (EMT) and MMPs. Finally, DNA methylation microarray revealed a lack of hypermethylation at the CTGF promoter, suggesting other mechanisms are associated with suppression of CTGF in NPC.

Conclusion

Our study demonstrates that reduced expression of CTGF promoted cell proliferation, migration, invasion and cell cycle progression through FAK/PI3K/AKT, EMT and MMP pathways in NPC.

Differential expression of lipid metabolism genes in the liver and adipose tissue of mice treated with evodiamine

Evodiamine is the main active alkali of Wu Zhuyu, a widely distributed Chinese herb. It plays an important role in the regulation of body fat deposition. In this study, we aimed to investigate the effect of evodiamine administration on the expression of genes involved in lipid metabolism in the liver and adipose tissue. Fasted mice were subcutaneously injected with evodiamine (37 °C, 20 mg/kg), and the core body temperature change and expression levels of lipid metabolism-related genes were evaluated at baseline, 0.5, 1, and 2 h. We detected the mRNA expression of fatty acid synthesis enzyme (FAS), peroxisome proliferator-activated receptor gamma (PPAR-γ), sterol regulatory element binding protein 1c (SREBP-1c), triglyceride hydrolase (TGH), and hormone-sensitive lipase (HSL) by real-time PCR and analyzed their correlation with core body temperature. Our results showed that the core body temperature was reduced greater than 1 °C with evodiamine treatment at 1 and 2 h (P < 0.01). In mouse livers, SREBP-1c, HSL, and TGH mRNA expression was significantly increased, and they reached the highest levels 1 h after injection (P < 0.01). However, PPAR-γ mRNA expression was decreased and reached a significant level at 0.5 h (P < 0.01) and FAS mRNA expression was not significantly different; FAS and SREBP-1c mRNA expression were reduced and reached significant levels at 1 h (P < 0.01). Of note, other genes demonstrated opposite changes in adipose tissue, and HSL mRNA expression was significantly reduced at 0.5 h (P < 0.01). The decreasing core temperature had a significant negative correlation with the expression of TGH, HSL, FAS, and SREBP- 1c mRNA in the liver (P < 0.01), but had significant positive correlation with levels of FAS and SREBP-1c mRNA in adipose tissue (P < 0.01). In light of these results, the main mechanism of the regulation of body fat deposition by evodiamine is raising energy consumption through reducing body temperature and promoting fat decomposition.

Construction of suppressor of cytokine signaling 2 (SOCS2) adenoviral overexpression vector and its impact on growth-hormone-induced lipolysis in swine primary adipocytes

We investigated the effect of overexpression suppressor of cytokine signaling 2 (SOCS2) on lipolysis in swine primary adipocytes (pAd) induced by growth hormone (GH). We constructed pAd-SOCS2 adenoviral overexpression vectors to infect HEK293 cells for virus packaging and propagation. Cultured swine primary adipocytes were infected with virus particles; after 48 h the infected adipocytes were treated with 500 ng GH/mL in the growth medium. Lipometabolism-related gene expressions were detected at 0, 0.25, 0.5, 1, 2, and 4 h, by measuring mRNA and protein levels. The pAd-SOCS2 overexpression vector was successfully constructed and the concentration of titrated virus was 1.2 x 10(9) PFU/mL. We found that virus infection significantly increased SOCS2 mRNA and protein levels in swine primary adipocytes. Overexpression of SOCS2 significantly inhibited the increase in fatty acid synthase, adipose triglyceride lipase mRNA, and protein expression at 0.5 h. However, after 0.5 h, this inhibition was not significant. We concluded that overexpression of SOCS2 inhibited the increase in lipolysis induced by GH in swine primary adipocytes; this could provide a basis for studies of lipometabolism.

SZ-685C exhibits potent anticancer activity in both radiosensitive and radioresistant NPC cells through the miR-205-PTEN-Akt pathway

Radioresistance is a major obstacle to the treatment of human nasopharyngeal carcinoma (NPC). Emerging evidence has demonstrated that miRNAs are involved in cancer therapy resistance. Our research group established the radioresistant NPC cell line CNE2R derived from the CNE2 cell line, and demonstrated that irradiation-induced miR-205 determined the resistance of NPC through directly targeting PTEN. However, specific inhibitors targeting miRNAs are largely undetermined. SZ-685C was expected to abrogate the radioresistance of CNE2 cells through the miR-205‑PTEN-Akt pathway. SZ-685C exhibited a similar cytotoxic effect on both cell lines, and we demonstrated that both intrinsic and extrinsic pathways were activated by SZ-685C in the cell lines. Importantly, the miR-205-PTEN-Akt pathway was the key cell signaling pathway activated in the CNE2R cells upon SZ-685C treatment; however, the Stat3-Jab1-p27 pathway might participate in the pro-apoptotic effect in CNE2 cells but not in CNE2R cells. SZ-685C is a promising anticancer agent for treatment of NPC, and it exhibited pro-apoptotic activity in both radiosensitive and radioresistant NPC cells. Although the mechanisms between the two cell lines were not identical, the pro-apoptotic effects were similar between the two cell lines.

Deuterium-depleted water (DDW) inhibits the proliferation and migration of nasopharyngeal carcinoma cells in vitro

Recent studies have demonstrated that natural water that has 65% of the deuterium concentration depleted, can exhibit anti-tumor properties. However, the anti-tumor effects of DDW on various nasopharyngeal carcinoma (NPC) cells have not previously been reported. In the present study, NPC cell lines and normal preosteoblast MC3T3-E1 cells were grown in RPMI1640 media containing different deuterium concentrations (50-150 ppm). The effects of DDW on the proliferation and migration of NPC and MC3T3-E1 cells were investigated using the MTT, plate colony formation, and Transwell assays, as well as Boyden chamber arrays, flow cytometry (FCM), western blot and immunofluorescence. We found that DDW was an effective inhibitor of NPC cell proliferation, plated colony formation, migration and invasion. In contrast, the growth of normal preosteoblast MC3T3-E1 cells was promoted when they were cultured in the presence of DDW. Cell cycle analysis revealed that DDW caused cell cycle arrest in the G1/S transition, reduced the number of cells in the S phase and significantly increased the population of cells in the G1 phase in NPC cells. Western blot analysis revealed that treatment with DDW significantly increased the expression of NADPH:quinone oxidoreductase-1 (NQO1), while immunofluorescence assay analysis revealed that treatment with DDW decreased the expression of PCNA and matrix metalloproteinase 9 (MMP9) in NPC cells. These results demonstrated that DDW is a novel, non-toxic adjuvant therapeutic agent that suppresses NPC cell proliferation, migration, and invasion by inducing the expression of NQO1 and causing cell cycle arrest, as well as decreasing PCNA and MMP9 expression.

[Effects on the antibacterial activity of TiO(2) nanotubes with different diameters from ultraviolet ray-irradiation]

OBJECTIVE

To study the effects of ultraviolet ray (UV)-irradiation on the surface characteristic and antibacterial activity of TiO(2) nanotubes with different diameters.

METHODS

TiO(2) nanotubes with different diameters were fabricated on polished pure titanium (PT) samples by anodization at 5, 10 and 20 V with PT as control. The samples were exposed to UV-irradiation for 24 h, then the characteristic and antibacterial activity were analyzed and evaluated. The surface topograph was observed by field emission scanning electron microscope (FE-SEM). Contract angle measurements were carried out with three liquids. Staphylococcus aureus (Sa) were used to evaluate the antibacterial activity of samples with the film contact method. The bacterial morphology was observed by FE-SEM. The bacterial adhesion and cell membrane injury were evaluated by fluorescent staining analysis under laser scanning confocal microscope (LSCM).

RESULTS

After the TiO(2) nanotubes with different diameters were exposed to UV-irradiation, no change was observed in its surface topograph. With the increase of the diameters of nanotubes, each contract angle of nanotubes decreased, and bacterial FIt and dead/live ratio were also increased. We found 20 V FIt was the biggest (26.550 ± 2.940) and ranks the highest ratio of death/live (0.728 ± 0.091) among the others (P < 0.05).

CONCLUSIONS

The UV-irradiation can decrease the contract angle of TiO(2) nanotubes and promote the Sa adhesion on nanotubes. Meanwhile, the antibacterial activity of TiO(2) nanotubes with different diameters was remarkably enhanced by UV-irradiation. Nanotubes anodized at 20 V showed the best antibacterial activity.

Development of robust hepatitis C virus genotype 4 subgenomic replicons

Despite the prevalence of hepatitis C virus genotype 4, no replicon system is available for study of the genotype. To facilitate discovery and development of reagents against this virus, we synthesized and transcribed a genotype 4a subgenomic replicon and transfected Huh7-Lunet cells with it, which yielded very few colonies. However, when we used a new Huh-7-derived cell line, colony formation increased ∼70-fold. We identified multiple adaptive mutations in the virus's nonstructural 3 or 4A proteins that allowed the cells to maintain stable, genotype 4a luciferase-encoding replicons. Several classes of hepatitis C virus inhibitors had different antiviral effects on genotypes 4a vs 1b. The genotype 4a replicon system we created will aid in the development of treatment regimens for all genotypes of hepatitis C virus.

Effect of Natural Hirudin on Random Pattern Skin Flap Survival in a Porcine Model

Objective:

The effect of local administration of hirudin on random pattern skin flap survival was investigated in a porcine model.

Methods:

Three random pattern skin flaps (4 × 14 cm) were created on each flank of five Chinese minipigs. The experimental group (10 flaps) received 20 antithrombin units of hirudin, injected subdermally into the distal half immediately after surgery and on days 1 and 2; a control group (10 flaps) was injected with saline and a sham group (10 flaps) was not injected. All flaps were followed for 10 days postoperatively.

Results:

Macroscopically, the congested/necrotic length in the experimental group was significantly decreased compared with the other two groups by day 3. Histopathological evaluation revealed venous congestion and inflammation in the control and sham groups from day 1, but minimal changes in the experimental group. By day 10, the mean ± SD surviving area was significantly greater in the experimental group (67.6 ± 2.1%) than in the control (45.2 ± 1.4%) or sham (48.3 ± 1.1%) groups.

Conclusions:

Local administration of hirudin can significantly increase the surviving area in overdimensioned random pattern skin flaps, in a porcine model.

Kyphoplasty for the Treatment of Very Severe Osteoporotic Vertebral Compression Fracture

Objective:

A retrospective evaluation of the clinical outcome and technical feasibility of kyphoplasty for the treatment of very severe osteoporotic vertebral compression fracture (vsOVCF).

Methods:

Patients with vsOVCF were treated with kyphoplasty and followed-up for 1 year. Vertebral body height variation, kyphotic angle, back pain (visual analogue scale [VAS]) and Oswestry disability index (ODI) were evaluated preoperatively, postoperatively, 1 month, 3 months and 1 year after treatment.

Results:

In total, 35 patients (49 vertebrae) were treated with kyphoplasty. There were no cases of spinal or extraspinal injury, infection, bleeding, pulmonary embolism, epidural cement leakage, stroke or cardiac arrest as a result of treatment. There were significant postoperative improvements in all outcome measures (vertebral body height variation, kyphotic angle, VAS and ODI); these improvements were maintained during the follow-up period.

Conclusion:

Kyphoplasty is an effective and minimally invasive procedure for the treatment of vsOVCF.

CDK inhibitor p57 (Kip2) is negatively regulated by COP9 signalosome subunit 6

Subunit 6 of the COP9 signalosome complex, CSN6, is known to be critical to the regulation of the MDM2-p53 axis for cell proliferation and anti-apoptosis, but its many targets remain unclear. Here we show that p57 (Kip2) is a target of CSN6, and that CSN6 is a negative regulator of p57 (Kip2) . CSN6 associates with p57 (Kip2) , and its overexpression can decrease the steady-state expression of p57 (Kip2) ; accordingly, CSN6 deficiency leads to p57 (Kip2) stabilization. Mechanistic studies show that CSN6 associates with p57 (Kip2) and Skp2, a component of the E3 ligase, which, in turn, facilitates Skp2-mediated protein ubiquitination of p57 (Kip2) . Loss of Skp2 compromised CSN6-mediated p57 (Kip2) destabilization, suggesting collaboration between Skp2 and CSN6 in degradation of p57 (Kip2) . CSN6's negative impact on p57 (Kip2) elevation translates into cell growth promotion, cell cycle deregulation and potentiated transformational activity. Significantly, univariate Kaplan-Meier analysis of tumor samples demonstrates that high CSN6 expression or low p57 expression is associated with poor overall survival. These data suggest that CSN6 is an important negative regulator of p57 (Kip2) , and that overexpression of CSN6 in many types of cancer could lead to decreased expression of p57 (Kip2) and result in promoted cancer cell growth.

HER2-Akt signaling in regulating COP9 signalsome subunit 6 and p53

HER2/neu oncogene is frequently overexpressed in various types of cancer, and the (PI3K)-Akt signaling pathway is often activated in HER2-overexpressing cancer cells. CSN6, subunit 6 of the COP9 signalosome complex, is pivotal in regulating MDM2 to destabilize p53, but its upstream regulators remain unclear. Here we show that the HER2-Akt axis is linked to CSN6 regulation, and that Akt is a positive regulator of CSN6. Ectopic expression of Akt can increase the expression of CSN6; accordingly, Akt inhibition leads to CSN6 destabilization. Mechanistic studies show that Akt causes CSN6 phosphorylation at Ser 60, which, in turn, reduces ubiquitin-mediated protein degradation of CSN6. Significantly, Akt's positive impact on CSN6 elevation translates into p53 degradation, potentiating transformational activity and increasing DNA damage. Akt inhibition can attenuate these defects caused by CSN6. These data suggest that Akt is an important positive regulator of CSN6, and that activation of Akt in many types of cancer could lead to abnormal elevation of CSN6 and result in downregulated p53 and increased DNA damage, which promotes cancer cell growth.

Proteomic features of potential tumor suppressor NESG1 in nasopharyngeal carcinoma

We previously defined the recently revised NESG1 gene as a potential tumor suppressor in nasopharyngeal carcinoma (NPC). Here, we further used proteomics technology to globally examine NESG1-controlled proteins in NPC cells. Twenty-six proteins were found to be deregulated by NESG1 using proteomics analysis while enolase 1 (alpha) (ENO1), heat shock protein 90 kDa beta (Grp94), member 1 (HSP90B1), and cathepsin D (CTSD) proteins were differentially expressed by Western blot. Interestingly, a-enolase (ENO1), an overexpressed gene in NPC, was confirmed as a NESG1-regulated protein in NPC cells. Overexpressed ENO1 not only restored cell proliferation and cell-cycle progression, but also antagonized the regulation of NESG1 to cell-cycle regulators p21 and CCNA1 expression as well as induced the expression of C-Myc, pRB, and E2F1 in NESG1-ovexpressed NPC cells. Real-time PCR and immunohistochemistry analysis showed that NESG1 expression is negatively correlated with ENO1 expression in NPC tissues. Our observations suggest that ENO1 downregulation plays an important role in NESG1-induced growth inhibition of NPC cancer cells.

[Deuterium-depleted water selectively inhibits nasopharyngeal carcinoma cell proliferation in vitro]

OBJECTIVE

To evaluate the inhibitory effect of deuterium-depleted water (DDW) on the proliferation of nasopharyngeal carcinoma (NPC) cells in vitro and explore the possible mechanism.

METHODS

The growth inhibition of NPC cells and preosteoblast MC3T3-E1 cells following DDW treatment was measured by MTT assay and plate colony formation assay. The changes in migration and invasion of NPC cells were evaluated using Transwell and boyden chamber assays. The protein expression of proliferating cell nuclear antigen (PCNA) was determined using Western blotting. Flow cytometry was employed to evaluate the changes in cell cycle distribution after DDW treatment.

RESULTS

DDW with deuterium concentrations of 100, 75 and 50 ppm significantly suppressed the cell proliferation (P<0.05) and lowered colony formation capacity and invasiveness of the NPC cells (P<0.01). Western blotting demonstrated a down-regulated expression of PCNA in the cells by DDW. DDW also caused obvious cell cycle arrest in the NPC cells with reduced cells in S phase and significantly increased cells in G(1) phase (P<0.05). Rather than causing growth inhibition, DDW promoted the growth of normal control MC3T3-E1 cells.

CONCLUSION

DDW possesses selective biological effects to inhibit the proliferation of NPC cells in vitro, suggesting the potential of DDW as a novel nontoxic adjuvant therapeutic agent in antitumor therapy.

[Research progress of the inhibitory effect of deuterium-depleted water on cancers]

Deuterium is an important predisposing factor for cancer. Deuterium-depleted Water, also known as low deuterium water, ultra-light water or no deuterium water, can be obtained by removing deuterium from natural water. Studies have shown that water with a low deuterium concentration (<65% percent of volume) can inhibit cancer growth. Clinical trials demonstrated that drinking DDW (10-20 ppm) caused growth arrest of malignant cells in cancer patients and significantly prolonged the patient survival with also improved quality of life. A wide range of anti-cancer drugs in current use are associated with severe adverse effects, while deuterium-depleted water appears to have virtually no pharmacological side effects and is convenient to administer. The authors review the advances in the researches of anti-cancer effects and the underlying mechanisms of deuterium-depleted water.

MiR-205 determines the radioresistance of human nasopharyngeal carcinoma by directly targeting PTEN

Radiotherapy is the primary treatment for nasopharyngeal carcinoma (NPC), but radioresistance severely reduces NPC radiocurability. Here, we have established a radio-resistant NPC cell line, CNE-2R, and investigate the role of miRNAs in radioresistance. The miRNAs microarray assay reveals that miRNAs are differentially expressed between CNE-2R and its parental cell line CNE-2. We find that miR-205 is elevated in CNE-2R. A target prediction algorithm suggests that miR‑205 regulates expression of PTEN, a tumor-suppressor. Introducing miR-205 into CNE-2 cells suppresses PTEN protein expression, followed by activation of AKT, increased number of foci formation and reduction of cell apoptosis postirradiation. On the other hand, knocking down miR-205 in CNE-2R cells compromises the inhibition of PTEN and increases cell apoptosis. Significantly, immunohistochemistry studies demonstrate that PTEN is downregulated at late stages of NPC, and that miR-205 is significantly elevated followed the radiotherapy. Our data conclude that miR-205 contributes to radioresistance of NPC by directly targeting PTEN. Both miR-205 and PTEN are potential predictive biomarkers for radiosensitivity of NPC and may serve as targets for achieve successful radiotherapy in NPC.

Bone healing response to a synthetic calcium sulfate/β-tricalcium phosphate graft material in a sheep vertebral body defect model

The introduction of a material able to promote osteogenesis and remodelling activity in a clinically relevant time frame in vertebroplasty and kyphoplasty procedures may have patient benefit. We report the in-vivo performance of a biphasic synthetic bone graft material (Genex Paste, Biocomposites, UK) [test material], composed of calcium sulfate and β-tricalcium phosphate, implanted into a sheep vertebral defect model. Cavities drilled into 4 adjacent vertebrae (L2 to L5) of 24 skeletally mature sheep were; (1) filled with the test material; (2) filled with commercially available polymethylmethacrylate [PMMA] cement; (3) remained empty [sham]. Analysis was performed immediately after implantation and at 8, 16, and 36 weeks post implantation. Sites were evaluated for bone growth with microCT analysis, histological examination, and mechanical testing under compression. The test material exhibited an improved tissue response over the PMMA, indicating a superior biological tolerance. MicroCT and histology indicated marked osteoregenerative capacity of the test material when compared with sham and the PMMA. The percentage of new bone formation was higher for the test material than sham at 16 and 36 weeks post implantation, with bone regeneration almost complete at 36 weeks in this group. Resorption of test material and the integration into new bone tissue were demonstrated. © 2012 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 2012.

Suppression of edge localized modes in high-confinement KSTAR plasmas by nonaxisymmetric magnetic perturbations

Edge localized modes (ELMs) in high-confinement mode plasmas were completely suppressed in KSTAR by applying n=1 nonaxisymmetric magnetic perturbations. Initially, the ELMs were intensified with a reduction of frequency, but completely suppressed later. The electron density had an initial 10% decrease followed by a gradual increase as ELMs were suppressed. Interesting phenomena such as a saturated evolution of edge T(e) and broadband changes of magnetic fluctuations were observed, suggesting the change of edge transport by the applied magnetic perturbations.

Overexpressed DNA-binding protein inhibitor 2 as an unfavorable prognosis factor promotes cell proliferation in nasopharyngeal carcinoma

The aim of the present study was to analyze the expression of DNA-binding protein inhibitor 2 (ID2) in nasopharyngeal carcinoma (NPC) and its correlation with clinicopathological features. It was found that the expression of ID2 was significantly increased in NPC cells when compared with that in NP69 cell line. Similar level of ID2 cytoplasmic expression was observed in NPC when compared with that in non-cancerous nasopharynx tissues. However, the level of ID2 in nucleus was increased in NPC when compared with that in normal nasopharynx tissues. Furthermore, the higher expression level of nuclear ID2 was significantly associated with tumor size (T classification), lymph node metastasis (N classification), and clinical stage. Patients with increased ID2 expression level had poorer overall survival rates than those with low ID2 levels. The inhibition of ID2 expression in NPC cell line SUNE1 by lentiviral-mediated short hairpin RNA could suppress cell proliferation and colony formation, but did not disrupt cell migration. Knocking down the expression of ID2 by RNA interference could down-regulate the expression of Snail, suggesting that ID2-promoted cell growth, partially attributing to the regulation of Snail activity in NPC. Our study demonstrated that over-expression of ID2 protein is an unfavorable prognostic factor which promotes cell proliferation in NPC.

Abstract 1855: Jab1/CSN5 a negative regulator of p27 plays a role in the pathogenesis and cisplatin sensitivity of nasopharyngeal carcinoma

Nasopharyngeal carcinoma (NPC) is an Epstein-Barr virus-associated malignancy most common in East Asia and Africa. Previous studies have reported that genetic susceptibility is associated with NPC. Jab1/CSN5 promotes cell growth and proliferation. Recent studies have shown that Jab1/CSN5 is aberrantly expressed, is correlated with low expression of p27, and is associated with advanced tumor stage and poor prognosis in several human cancers. In this study, we examined the functional role and correlation between Jab1/CSN5 and p27 protein expression in NPC tissue samples and cell lines, the association of their expression with clinical outcome and the antitumor effects of cisplatin in NPC cells. Immunohistochemical analysis showed that Jab1/CSN5 aberrant expression was inversely associated with p27 expression in NPC tissue samples, and Jab1/CSN5 overexpression was correlated with poor survival (p&lt;0.01). Further analysis showed that Jab1/CSN5 mediated p27 degradation in a proteasome-dependent manner, and Jab1/CSN5 directly interacted with p27 in NPC cells. In addition, inactivation of Jab1/CSN5 by small interfering RNAs resulted in a remarkable increase in p27 levels and in the inhibition of cell proliferation, thereby indicating that Jab1/CSN5 controls the stability of p27 by targeting it for degradation in NPC. Moreover, suppression of Jab1/CSN5 enhanced the antitumor effects of cisplatin in NPC cells. To our knowledge, these findings are the first to suggest that Jab1/CSN5 overexpression is involved in NPC pathogenesis via Jab1-mediated p27 degradation, thus explaining the low p27 levels seen in NPC. Therefore, Jab1/CSN5 could be a diagnostic marker and a novel therapeutic target in patients with NPC.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 103rd Annual Meeting of the American Association for Cancer Research; 2012 Mar 31-Apr 4; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2012;72(8 Suppl):Abstract nr 1855. doi:1538-7445.AM2012-1855

Biochemical evaluation of HCV NS3 protease inhibitors

This unit describes assays for characterizing the potency and mechanism of action of NS3 protease inhibitors. Determination of IC(50) values is described using in vitro expressed and purified NS3 protease. This assay can also be used for the rapid exploration of structure-activity relationships. Another protocol describes using the full-length NS3/4A complexes expressed in HCV replicon cell lines for a rapid alternative method for assessing protease activity without requiring conventional protein expression and purification. A method is then provided for determination of inhibitor K(i), which more accurately assesses the potency of inhibitors compared to the IC(50) assay, particularly for potent inhibitors that reach the sensitivity limit for the basic IC(50) assay. The final protocol describes how to determine the reversibility of inhibitor binding to the enzyme, an important parameter that can affect the pharmacodynamic properties of a compound.

Jab1/CSN5 negatively regulates p27 and plays a role in the pathogenesis of nasopharyngeal carcinoma

Nasopharyngeal carcinoma (NPC) is an Epstein-Barr virus-associated malignancy most common in East Asia and Africa. Aberrant expression of Jab1/CSN5, a negative regulator of the cell-cycle inhibitor p27, is correlated with reduced p27 expression and associated with advanced tumor stage and poor prognosis in several human cancers. In this study, we examined the functional relationship between Jab1 and p27 protein expression in NPC. Immunohistochemical analysis showed an inverse association between Jab1 and p27 in NPC tissue samples, and overexpression of Jab1 correlated with poor survival in patients with NPC. Mechanistically, Jab1 and p27 were found to interact directly in NPC cells, with Jab1 mediating p27 degradation in a proteasome-dependent manner. Knockdown of Jab1 resulted in a remarkable increase in p27 levels and inhibition of cell proliferation, indicating that Jab1 targets p27 for degradation, thereby controlling its stability. Jab1 depletion also enhanced the antitumor effects of cisplatin in NPC cells. Together, our findings suggest that Jab1 overexpression plays an important role in the pathogenesis of NPC through Jab1-mediated p27 degradation. Jab1 therefore represents a novel diagnostic marker and therapeutic target in patients with NPC.