Irradiation-induced dynamic changes of gene signatures reveal gain of metastatic ability in nasopharyngeal carcinoma

Nasopharyngeal carcinoma (NPC), arising from the nasopharynx epithelium, is prevalent among South and East Asia. The radiotherapy is the primary treatment for NPC patients. However, the acquired radioresistance dramatically diminishes the therapeutic effect of radiotherapy. Meanwhile, recurrence and metastasis always occur in line with the radioresistance, but the underlying mechanisms are still unclear. In this study, we established two radioresistant NPC cell lines, CNE1R and SUNE1R, by sequentially irradiated parental CNE1 and SUNE1 cells up to a clinical treatment dose of 72 Gy. A transcriptome profile analysis of CNE1R and CNE1 reveals that activated oncogenic pathways are highly enriched in CNE1R. As the result, CNE1R showed higher proliferation rate but lower apoptosis rate after irradiation, and enhanced metastasis ability in comparison with CNE1. Significantly, a group of metastasis associated genes were increased in CNE1R while the irradiation proceeded, including several matrix metallopeptidase (MMP) members, especially MMP10 and MMP13. With further analysis, we found both MMP10 and MMP13 are highly upregulated in metastatic head and neck cancer specimens compared to non-metastatic ones. More importantly, patients with lower expression of both MMP10 and MMP13 showed a better five-year survival than the double high group. Our findings unveiled the potential mechanisms of radioresistance related metastasis in NPC patients, and the increase of MMP10 and MMP13 may serve as high risk factors for metastasis during radiotherapy.

[Expressions and prognostic significance of PTEN and PD-1 protein in patients with classical Hodgkin's lymphoma]

目的

分析肿瘤免疫耐受信号通路的重要因子PD-1和PTEN在经典型霍奇金淋巴瘤（CHL）患者中的表达及其与患者临床特征和预后的相关性。

方法

回顾性分析2003年2月至2013年8月诊治的56例CHL患者的临床资料。采用免疫组织化学染色法检测CHL患者PD-1和PTEN蛋白的表达，采用原位杂交法检测EBV及EBV编码的小mRNA（EBER），并结合患者的临床特征与生存状态进行相关性分析。

结果

①56例患者中，男34例，女22例，中位年龄25（7~71）岁，PTEN阳性者11例（19.64%），PD-1阳性者14例（25.00%）。②PTEN和PD-1表达呈正相关（rs=0.320，P=0.016）；PTEN表达与Ann Arbor分期、IPS评分和有无大包块（≥5 cm）明显相关，PD-1仅与有无大包块相关（P值均<0.05）。③中位随访43（5~86）个月，多因素分析结果显示：年龄≥45岁（P<0.001）、IPS评分>2分（P=0.026）、EBER阳性（P=0.004）、PTEN蛋白高表达（P=0.035）是影响患者5年总生存的不良预后因素，也是影响5年无进展生存的不良预后因素（P值分别为0.007、0.014、0.002、0.024）。

结论

肿瘤免疫逃逸信号通路因子PTEN与CHL患者的预后相关，对CHL患者的预后判断有一定作用，同时也为CHL的免疫治疗提供了新思路和理论依据。

Recycling and reuse of kerf-loss silicon from diamond wire sawing for photovoltaic industry

With the rapid growth of the global photovoltaic (PV) industry, the waste from PV industry cannot be ignored, especially the solid wastes from silicon kerf loss and the used quartz crucibles from silicon casting. The silicon kerf loss during wafer sawing was nearly 160,000 tonnes and the used crucible waste was nearly 70,000 tonnes in 2017. With the transition of wafering technology from the slurry-based wire to diamond wire sawing, recycling and reuse of kerf-loss silicon have become more feasible due to the lower impurity contents. In this paper, we aimed to find a simple approach to recycle the kerf loss and identify the purity for reuse. We first analyzed the contents of the as-received kerf-loss silicon from the industry. Then, suitable acids and refining procedure were proposed. The metals, especially nickel, could be easily reduced to several ppmw, boron and phosphorous to sub-ppmw, and carbon to several hundred ppmw, while oxygen was less than 5 wt%. Although the purity of the recycled silicon was not sufficient for casting feedstock, it had a comparable purity of about 5 N with the commercial silicon nitride releasing agent and crucibles used in silicon casting for solar cells. Because the nitride crucibles could be reused a few times for casting, the used crucible waste could be significantly reduced as well.

hsa‑miR‑24 suppresses metastasis in nasopharyngeal carcinoma by regulating the c‑Myc/epithelial‑mesenchymal transition axis

Distant metastasis is the major contributor to treatment failure and mortality in patients with nasopharyngeal carcinoma (NPC). The lack of effective treatment strategies for metastatic NPC is the major cause for the low survival rate. Therefore, it is crucial to understand the molecular mechanisms underlying NPC metastasis and to identify potential biomarkers for targeted therapy. MicroRNA (miRNAs or miRs) have been shown to play an important role in tumorigenesis and metastasis. In the present study, we aimed to evaluate the significance of hsa-miR-24 in NPC metastasis. Significantly lower hsa-miR-24 levels were observed in NPC metastatic tumors and higher hsa-miR-24 levels were associated with longer progression-free and metastasis-free survival durations. hsa-miR-24 overexpression inhibited cell proliferation, invasion and migration. Using bioinformatics approaches together with functional luciferase reporter assays, we demonstrated that the c-Myc 3′-UTR was a direct target of hsa-miR-24 in regulating NPC metastasis. Protein profiling analysis revealed that a high c-Myc expression was inversely associated with metastasis-free overall survival and with epithelial-mesenchymal transition (EMT). Furthermore, the overexpression of hsa-miR-24 decreased NPC cell invasive ability induced by the overexpression of c-Myc, associated with EMT epithelial marker (E-cadherin) restoration. Thus, on the whole, the findings of this study demonstrate that hsa-miR-24 suppresses metastasis in NPC by regulating the c-Myc/EMT axis, suggesting that hsa-miR-24 may be used as a prognostic factor and as a novel target for the prevention of NPC metastasis.

FOXM1 promotes reprogramming of glucose metabolism in epithelial ovarian cancer cells via activation of GLUT1 and HK2 transcription

Cancer cells exhibit the reprogrammed metabolism mainly via aerobic glycolysis, a phenomenon known historically as the Warburg effect; however, the underlying mechanisms remain largely unknown. In this study, we characterized the critical role of transcription factor Forkhead box protein M1 (FOXM1) in aerobic glycolysis of human epithelial ovarian cancer (EOC) and its molecular mechanisms. Our data showed that aberrant expression of FOXM1 significantly contributed to the reprogramming of glucose metabolism in EOC cells. Aerobic glycolysis and cell proliferation were down-regulated in EOC cells when FOXM1 gene expression was suppressed by RNA interference. Moreover, knockdown of FOXM1 in EOC cells significantly reduced glucose transporter 1 (GLUT1) and hexokinase 2 (HK2) expression. FOXM1 bound directly to the GLUT1 and HK2 promoter regions and regulated the promoter activities and the expression of the genes at the transcriptional level. This reveals a novel mechanism by which glucose metabolism is regulated by FOXM1. Importantly, we further demonstrated that the expression levels of FOXM1, GLUT1 and HK2 were significantly increased in human EOC tissues relative to normal ovarian tissues, and that FOXM1 expression was positively correlated with GLUT1 and HK2 expression. Taken together, our results show that FOXM1 promotes reprogramming of glucose metabolism in EOC cells via activation of GLUT1 and HK2 transcription, suggesting that FOXM1 may be an important target in aerobic glycolysis pathway for developing novel anticancer agents.

A directly negative interaction of miR-203 and ZEB2 modulates tumor stemness and chemotherapy resistance in nasopharyngeal carcinoma

miR-203 is a tumor suppressor that is disregulated in numerous malignancies including nasopharyngeal carcinoma (NPC). However, the role of miR-203 in suppressing tumor stemness, chemotherapy resistance as well as its molecular mechanisms are unclear. In this study, we observed that miR-203 suppressed cell migration, invasion, tumor stemness, and chemotherapy resistance to cisplatin (DDP) in vitro and in vivo. miR-203 exerted these effects by targeting ZEB2 and downstream epithelial-mesenchymal transition (EMT) and tumor stemness signals. Interestingly we observed that miR-203 expression was directly suppressed by ZEB2 via targeting its promoter, which significantly reduced cell migration, invasion, tumor stemness, and chemotherapy resistance in NPC cells. Finally, we found that miR-203 was negatively correlated with ZEB2 expression in NPC tissues and tumor spheres. Our data demonstrate a directly negative feedback loop between miR-203 and ZEB2 participating in tumor stemness and chemotherapy resistance, highlighting the therapeutic potential of targeting this signal for NPC chemotherapy.

Anti-apoptotic function of herpes simplex virus -2 latency-associated transcript RL1 sequence and screening of its encoded microRNAs

BACKGROUND

The latency-associated transcript (LAT) gene of herpes simplex virus (HSV)-2 is the only detectable viral gene expressed during latent infection in neurons. LAT inhibits apoptosis and maintains latency by promoting the survival of infected neurons. However, whether LAT functions during HSV-2 infection via its encoded RNAs or via its encoded proteins remain unknown. Increasing evidence has indicated that LAT is likely to functionally promote the establishment of latent infection via LAT-encoded microRNAs (miRNAs).

AIM

To explore whether the RL1 fragment of the five adjacent miRNAs has an effect on cell apoptosis, then provide supporting evidence to elucidate the potential role of these miRNAs and to aid screening of their cellular targets.

METHODS

A number of techniques, including MTT assay, flow cytometry and DNA ladder analysis, were used to verify the role of the RL1 fragment and the contribution of the individual miRNAs to the anti-apoptotic effect.

RESULTS

Five miRNAs (miR-H3, miR-H4-3p, miR-H4-5p, miR-H24 and miR-H19) were detected by quantitative PCR in PC12 cells stably expressing RL1 after pEGFP-RL1 plasmid transfection in vitro. The data indicated that expression of HSV-2 LAT RL1 seems to provide protection against apoptosis of PC12 cells induced by ActD. Antisense miRNAs specifically inhibiting these five miRNAs could efficiently reduce their expression. Transfection of antisense-miR-H3, antisense-miR-H4-5p and antisense-miR-H19 into PC12 cells stably expressing RL1 were able to partly reverse the anti-apoptotic effect of these miRNAs.

CONCLUSIONS

These findings indicate that the apoptotic role of the RL1 fragment is likely to be related to overexpression of miR-H3, miR-H4-5p and miR-H19 in PC12 cells.

FOXM1 confers resistance to gefitinib in lung adenocarcinoma via a MET/AKT-dependent positive feedback loop

Gefitinib resistance remains a major problem in the treatment of lung adenocarcinoma. However, the molecular mechanisms of gefitinib resistance are not fully understood. In this study, we characterized the critical role of transcription factor Forkhead box protein M1 (FOXM1) in gefitinib resistance of lung adenocarcinoma cells. In vitro drug sensitivity assays demonstrated that FOXM1 inhibition sensitized PC9/GR and HCC827/GR cells to gefitinib, whereas FOXM1 overexpression enhanced PC9 and HCC827 cell resistance to gefitinib. Increased FOXM1 resulted in the upregulation of hepatocyte growth factor receptor (MET), which led to activation of the protein kinase B (AKT) pathway, whereas knockdown of FOXM1 did the opposite. FOXM1 bound directly to the MET promoter regions and regulated the promoter activities and the expression of MET at the transcriptional level. Moreover, MET/AKT pathway upregulated the expression of FOXM1 in lung adenocarcinoma cells. Inhibition of pAKT by LY294002 or inhibition of pMET by PHA-665752 significantly inhibited the expression of FOXM1 in lung adenocarcinoma cells. Importantly, we further demonstrated that the expression levels of FOXM1, pAKT and MET were significantly increased in lung adenocarcinoma tissues relative to normal lung tissues, and these three biomarkers were concomitantly overexpressed in lung adenocarcinoma tissues. Taken together, our results indicate that FOXM1 promotes acquired resistance to gefitinib of lung adenocarcinoma cells, and FOXM1 crosstalks with MET/AKT signaling to form a positive feedback loop to promote lung adenocarcinoma development.

Metformin reduces SATB2-mediated osteosarcoma stem cell-like phenotype and tumor growth via inhibition of N-cadherin/NF-kB signaling

OBJECTIVE

To investigate the role of SATB2 in stem cell-like properties of osteosarcoma and identify new strategies to eliminate cancer stem cells of osteosarcoma.

MATERIALS AND METHODS

Osteosarcoma cancer stem cells were derived by sarcosphere generation or chemo drug enrichment. SATB2 and pluripotency-associated gene expression in osteosarcoma CSCs were analyzed using qRT-PCR and Western blotting. The sphere formation assay, cell counting kit-8 assay and anti-chemotherapy proteins were used to measure the effects of altered SATB2, N-cadherin expression or metformin treatment in CSCs. Nude mice were injected with SATB2-deficient U2OS/MTX cells to assess the role of SATB2 in osteosarcoma growth and chemoresistance in vivo. Bioinformatics analyses were performed to identify SATB2 downstream target genes and immunochemistry to determine the correlation between SATB2 expression and patient outcome. Western blotting and luciferase reporter assays were used to examine the effects of N-cadherin and SATB2 inhibition on the NF-kB pathway.

RESULTS

SATB2 was upregulated in osteosarcoma stem cells. Knockdown of SATB2 decreased sarcosphere formation, cell proliferation and stem cell-like gene expression in vitro, meanwhile reduced tumor growth and chemoresistance in vivo. High SATB2 expression in osteosarcoma patient samples was associated with poor clinical outcome. N-cadherin was one critical downstream target gene of SATB2 that mediated the stem cell-like phenotype. Reduction of SATB2 or N-cadherin resulted in NF-kB inactivation, which led to impaired osteosarcoma sphere formation and tumor cell proliferation. Metformin treatment of osteosarcoma cells enhanced the effects of chemotherapy via suppression of N-cadherin.

CONCLUSIONS

SATB2 plays an important role in regulating osteosarcoma stem cell-like properties and tumor growth. The combination of conventional chemotherapy and metformin may be a promising therapeutic strategy for osteosarcoma patients.

Retrospective analysis of 20 cases of refractory Hodgkin's lymphoma

We investigate the clinical characteristics, prognosis and treatment of relapsed and refractory Hodgkin's lymphoma. Twenty patients with relapsed and refractory Hodgkin lymphoma were treated by chemotherapy or autologous stem cell transplantation in our hospital from April 2006 to August 2012. The retrospective analysis of the records from the 20 patients reflected both 5-year overall survival (OS) and progression-free survival (PFS). The overall effectiveness was 80% for the 20 patients. The 5-year overall survival rate and 5-year progression-free survival rate were 73.5% and 62.7%, respectively. Therefore, comprehensive treatment should be actively utilized in the case of invalid second-line regimen for the refractory HL patients.

[Expression and prognostic significance of microenvironment related prognostic factors in patients with classical Hodgkin's lymphoma]

Objective: To observe the expression of three microenvironment related prognostic factors, i. e. programmed death 1 (PD-1), forkhead box protein 3(FOXP3) and colony-stimulating factor 1 receptor(CSF-1R) protein in classical Hodgkin's lymphoma (CHL) patients, and to explore the correlation between the protein expression and the prognosis of the patients. Methods: A total of 45 cases of CHL patients, who had been admitted to the Tianjin Medical University Cancer Institute and Hospital and Chinese PLA General Hospital from February 2005 to August 2010 were analyzed, including clinical features, prognostic factors, and treatment regimens. CHL patients' specimens were collected and the expression of PD-1, FOXP3, and CSF-1R proteins analyzed by immunohistochemical staining. Epstein-Barr virus encoded mRNA (EBER) was detected by in situ hybridization analysis. The relationship between the protein expression of PD-1, FOXP3 and CSF-1R and the patients' outcome was analyzed with clinical and follow-up data. Survival analysis was performed by Kaplan-Meier method, the Cox proportional hazard model was used to perform multivariate analysis. Results: In this cohort of 45 CHL patients, PD-1 positive was found in 7 cases (15.6%), FOXP3 high expression in 23 cases (51.1%), CSF-1R positive in 18 cases (40.0%). In the univariate analysis, the expression of FOXP3 and CSF-1R, International Prognostic Index (IPI) score, Ann Arbor stage and EBER were related with the patients' 5-year overall survival (OS); IPI score, the expression of FOXP3 and EBER were related with the patients' 5-year progress-free survival (PFS). Multivariate analysis indicated that CSF-1R protein expression was the independent prognostic factor affecting the patients' 5-year OS(HR: 8.918, P=0.020), and FOXP3 protein expression was the independent prognostic factor affecting the patients' 5-year PFS (HR: 0.122, P<0.001). And EBV was an independent prognostic factor of PFS and OS in the CHL patients. Conclusion: Microenvironment related prognostic factors FOXP3, CSF-1R and EBV may be independent prognostic factors of CHL and this study may provide novel strategies for targeted therapy of CHL.

[Clinical analysis of 9 cases with Anti-leucine-rich glioma inactivated 1 protein antibody associated limbic encephalitis]

Objective: This study was to describe the clinical characteristics of Anti-leucine-rich glioma inactivated 1 protein(LGI1) antibody associated limbic encephalitis. Methods: Clinical data including clinical features, laboratory and radiological findings, treatment and prognosis of the 9 patients were analyzed. Results: In all 9 cases, 6 cases experienced epileptic seizure, 5 cases had psychosis, 7 cases presented with memory impairment, 4 cases showed faciobrachial dystonic seizure, 2 had refractory hyponatremia. One case presented with typically acute Guillain-Barre syndrome (GBS). Anti-LGI1 antibody was detected in 6 cases in cerebrospinal fluid (CSF) samples and 9 in serum samples. Seven cases out of 9 had brain imaging abnormalities. All 9 cases found no evidence of tumors. Eight cases were given immune therapy. During a 1-16 months follow-up, 1 case had complete recovery, 5cases had various degree of sequelae , among whom 4 had memory disturbance and 1 case had changed personality. 2cases were lost to follow-up. Conclusions: Limbic encephalitis is the most common manifestation of anti-LGI1 antibody associated encephalitis. Faciobrachial dystonic seizure (FBDS) is a specific symptom which favors an early diagnosis. Tumor is uncommon to see. The disease has a relatively favorable prognosis while impaired memory can be seen as a common sequelae.

[Misdiagnosis and associated costs of benign paroxysmal positional vertigo]

Objective: The aims of this study were to investigate the misdiagnosis of benign paroxysmal positional vertigo (BPPV) and to estimate the associated costs. Methods: During October 2015 to December 2015, eighty patients were diagnosed with BPPV in the outpatient dizziness clinic of Shanghai Changzheng Hospital and the clinical data of all the 80 patients were collected including the demographic and clinical characteristics, the history of diagnosis, inappropriate diagnostic tests, costs of the medical tests, transportation and accommodation. All the data were investigated to estimate the misdiagnosis of benign paroxysmal positional vertigo and the associated costs in Shanghai, China. Results: This study showed that the misdiagnosis rate of BPPV was 60.0% (48/80) and the common inappropriate diagnostic tests for BPPV included Cranial CT and MRI test, cervical MRI, cervical and cerebrovascular investigations et al. There was no significant difference between the misdiagnosis patients (48) and patients without misdiagnosis (32) in gender, age, duration of symptom, involved canal and type of BPPV.Complications were significantly more frequent in the misdiagnosis group than for those without[81.3%(39 /48) vs 34.4%(11 /32)]. The estimated costs for each misdiagnosed individual were 8 502.98 China Yuan (CNY) and one-year economic burden associated with the misdiagnosis of BPPV in Shanghai was 13.184 7-78.862 1 million CNY. Conclusions: Our study suggests that the misdiagnosis rate of BPPV is high and the financial impact on patients and society with this disease is huge. The cost-effective Dix-Hallpike or supine roll test maneuver should be used before applying other expensive medical tests in order to minimize misdiagnosis and the waste of health care resources.

Treatment of Ribbing disease with 5-year follow-up and literature review

Ribbing disease, or multiple diaphyseal sclerosis, is a rare diaphyseal sclerosis of unknown etiology. Patients with this pathology usually present with asymmetric pain limited to the lower extremities. Though all efforts are made to relieve the progressive pain associated with Ribbing disease, no medical or surgical treatments have been established yet. In this case report, we followed up a Ribbing case with sclerotic bone fenestration for 5 years. The radiological changes and the clinical effects are described, and the different Ribbing treatments are then briefly reviewed.

Discovery of a 2'-fluoro-2'-C-methyl C-nucleotide HCV polymerase inhibitor and a phosphoramidate prodrug with favorable properties

A series of 2'-fluorinated C-nucleosides were prepared and tested for anti-HCV activity. Among them, the triphosphate of 2'-fluoro-2'-C-methyl adenosine C-nucleoside (15) was a potent and selective inhibitor of the NS5B polymerase and maintained activity against the S282T resistance mutant. A number of phosphoramidate prodrugs were then prepared and evaluated leading to the identification of the 1-aminocyclobutane-1-carboxylic acid isopropyl ester variant (53) with favorable pharmacokinetic properties including efficient liver delivery in animals.

Preclinical characterization of the novel HCV NS3 protease inhibitor GS-9256

BACKGROUND

GS-9256 is an inhibitor of HCV NS3 protease with a macrocyclic structure and novel phosphinic acid pharmacophore.

METHODS

Key preclinical properties of GS-9256 including in vitro antiviral activity, cross-resistance and pharmacokinetic properties were investigated in non-human species.

RESULTS

In genotype (GT) 1b Huh-luc cells with a replicon encoding luciferase, GS-9256 had a mean 50% effective concentration (EC₅₀) value of 20.0 nM, with minimal cytotoxicity. Antiviral activity was similar in a number of additional GT1b and GT1a replicon cell lines. Similar potency was observed in chimeric replicons encoding the NS3 protease of GT1 clinical isolates. GS-9256 was less active in GT2a replicon cells (14.2-fold increase in EC₅₀). Additive to synergistic in vitro antiviral activity was observed when GS-9256 was combined with other agents including interferon-α, ribavirin, NS5B polymerase inhibitors GS-6620 and tegobuvir, as well as the NS5A inhibitor ledipasvir. GS-9256 retained wild-type activity against all tested NS5B and NS5A inhibitor resistance mutations. GS-9256 was metabolically stable in microsomes and hepatocytes of tested species, including rodents, dogs and humans. GS-9256 had high bioavailability in mice (near 100%) and moderate bioavailability in rats (14%), dogs (21%) and monkeys (14%). Elimination half-lives were approximately 2 h in mice, 0.6 h in rats, 5 h in dogs and 4 h in monkey. A study in bile duct-cannulated rats indicated that the major route of elimination is through biliary excretion of unmetabolized GS-9256.

CONCLUSIONS

GS-9256 showed a favourable preclinical profile supportive of clinical development for the treatment of chronic HCV infection in GT1 patients.

Novel biomarkers of nasopharyngeal carcinoma metastasis risk identified by reverse phase protein array based tumor profiling with consideration of plasma Epstein-Barr virus DNA load

PURPOSE

In patients with Epstein-Barr virus (EBV) associated nasopharyngeal carcinoma (NPC), intertumor heterogeneity causes interpatient heterogeneity in the risk of distant metastasis. We aimed to identify novel biomarkers of metastasis risk using reverse phase protein array (RPPA) profiling of NPC patients at risk for metastasis and considering plasma EBV DNA load.

EXPERIMENTAL DESIGN

A total of 98 patients with NPC with and without metastasis after treatment, matched with respect to clinical parameters, are enrolled. Total protein expression is measured by RPPA, and protein functions are analyzed by pathway bioinformatics.

RESULTS

The RPPA analysis revealed a profile of 70 proteins that are differentially expressed in metastatic and nonmetastatic tumors. Plasma EBV DNA load after treatment correlated with protein expression level better than plasma EBV DNA load before treatment did. The biomarkers of NPC metastasis identified by proteomics regulate signaling pathways involved in cell cycle progression, apoptosis, and epithelial-mesenchymal transition. The authors identified 26 biomarkers associated with 5-year distant failure-free survival in univariate analysis; five biomarkers remained significant in multivariate analysis.

CONCLUSIONS AND CLINICAL RELEVANCE

A comprehensive RPPA profiling study is warranted to identify novel metastasis-related biomarkers and further examine the activation state of signaling proteins to improve estimation of metastasis risk for patients with EBV-associated NPC.

Constructing Hierarchical Tectorum-like α-Fe2 O3 /PPy Nanoarrays on Carbon Cloth for Solid-State Asymmetric Supercapacitors

The design of complex heterostructured electrode materials that deliver superior electrochemical performances to their individual counterparts has stimulated intensive research on configuring supercapacitors with high energy and power densities. Herein we fabricate hierarchical tectorum-like α-Fe₂ O₃ /polypyrrole (PPy) nanoarrays (T-Fe₂ O₃ /PPy NAs). The 3D, and interconnected T-Fe₂ O₃ /PPy NAs are successfully grown on conductive carbon cloth through an easy self-sacrificing template and in situ vapor-phase polymerization route under mild conditions. The electrode made of the T-Fe₂ O₃ /PPy NAs exhibits a high areal capacitance of 382.4 mF cm^-2 at a current density of 0.5 mA cm^-2 and excellent reversibility. The solid-state asymmetric supercapacitor consisting of T-Fe₂ O₃ /PPy NAs and MnO₂ electrodes achieves a high energy density of 0.22 mWh cm^-3 at a power density of 165.6 mW cm^-3 .

Cytotoxicity and genotoxicity in liver cells induced by cobalt nanoparticles and ions

Objectives

The cytotoxicity induced by cobalt ions (Co²⁺) and cobalt nanoparticles (Co-NPs) which released following the insertion of a total hip prosthesis, has been reported. However, little is known about the underlying mechanisms. In this study, we investigate the toxic effect of Co²⁺ and Co-NPs on liver cells, and explain further the potential mechanisms.

Methods

Co-NPs were characterised for size, shape, elemental analysis, and hydrodynamic diameter, and were assessed by Transmission Electron Microscope, Scanning Electron Microscope, Energy Dispersive X-ray Spectroscopy and Dynamic Light Scattering. BRL-3A cells were used in this study. Cytotoxicity was evaluated by MTT and lactate dehydrogenase release assay. In order to clarify the potential mechanisms, reactive oxygen species, Bax/Bcl-2 mRNA expression, IL-8 mRNA expression and DNA damage were assessed on BRL-3A cells after Co²⁺ or Co-NPs treatment.

Results

Results showed cytotoxic effects of Co²⁺ and Co-NPs were dependent upon time and dosage, and the cytotoxicity of Co-NPs was greater than that of Co²⁺. In addition, Co-NPs elicited a significant (p < 0.05) reduction in cell viability with a concomitant increase in lactic dehydrogenase release, reactive oxygen species generation, IL-8 mRNA expression, Bax/Bcl-2 mRNA expression and DNA damage after 24 hours of exposure.

Conclusion

Co-NPs induced greater cytotoxicity and genotoxicity in BRL-3A cells than Co²⁺. Cell membrane damage, oxidative stress, immune inflammation and DNA damage may play an important role in the effects of Co-NPs on liver cells.

Cite this article: Y. K. Liu, X. X. Deng, H.L. Yang. Cytotoxicity and genotoxicity in liver cells induced by cobalt nanoparticles and ions. Bone Joint Res 2016;5:461–469. DOI: 10.1302/2046-3758.510.BJR-2016-0016.R1.