Predictors of failure to detect early hepatocellular carcinoma in patients with chronic hepatitis B who received regular surveillance.

BACKGROUND: A proportion of chronic hepatitis B (CHB) patients are diagnosed with advanced hepatocellular carcinoma (HCC) despite regular surveillance. AIMS: To determine predictors for HCC detection failure in CHB patients who underwent regular surveillance. METHODS: CHB patients with well-preserved liver function, who underwent ultrasonography and alpha-foetoprotein (AFP) analysis every 6 months, were enrolled. Cox regression analysis was used to identify predictors for detection failure, defined as HCC initially diagnosed at Barcelona Clinic Liver Cancer (BCLC) stage B or C. RESULTS: Of the 4590 CHB patients (mean age, 52.1 years; men, 61.6%), 169 patients were diagnosed with HCC (3.68%) and 35 (20.7%) HCC patients were initially diagnosed with HCC BCLC stage B or C. The cumulative incidence of HCC detection failure was 0.2% at year 1 and 1.3% at year 5. Multivariate analyses indicated that cirrhosis (hazard ratio [HR], 3.078; 95% CI, 1.389-6.821; P = 0.006), AFP levels ≥9 ng/mL (HR, 5.235; 95% CI, 2.307-11.957; P = 0.010), and diabetes mellitus (HR, 3.336; 95% CI, 1.341-8.296; P = 0.010) were independent predictors of HCC detection failure. Another model that incorporated liver stiffness (LS) values identified LS values ≥11.7 kPa (HR, 11.045; 95% CI, 2.066-59.037; P = 0.005) and AFP levels ≥9 ng/mL (HR, 4.802; 95% CI, 1.613-14.297; P = 0.005) as predictors of detection failure. CONCLUSIONS: In CHB patients undergoing regular surveillance with ultrasonography and alpha-foetoprotein (AFP) analysis every 6 months, the HCC detection failure rate was not high (0.8% per person; 0.1% per test). However, careful attention should be paid in patients with advanced liver fibrosis (clinical cirrhosis or LS value >11.7 kPa), high AFP levels, or diabetes mellitus, who are prone to surveillance failure.

Peroxiredoxin II promotes hepatic tumorigenesis through cooperation with Ras/Forkhead box M1 signaling pathway.

The current study was carried out to define the involvement of Peroxiredoxin (Prx) II in progression of hepatocellular carcinoma (HCC) and the underlying molecular mechanism(s). Expression and function of Prx II in HCC was determined using H-ras(G12V)-transformed HCC cells (H-ras(G12V)-HCC cells) and the tumor livers from H-ras(G12V)-transgenic (Tg) mice and HCC patients. Prx II was upregulated in H-ras(G12V)-HCC cells and H-ras(G12V)-Tg mouse tumor livers, the expression pattern of which highly similar to that of forkhead Box M1 (FoxM1). Moreover, either knockdown of FoxM1 or site-directed mutagenesis of FoxM1-binding site of Prx II promoter significantly reduced Prx II levels in H-ras(G12V)-HCC cells, indicating FoxM1 as a direct transcription factor of Prx II in HCC. Interestingly, the null mutation of Prx II markedly decreased the number and size of tumors in H-ras(G12V)-Tg livers. Consistent with this, knockdown of Prx II in H-ras(G12V)-HCC cells reduced the expression of cyclin D1, cell proliferation, anchorage-independent growth and tumor formation in athymic nude mice, whereas overexpression of Prx II increased or aggravated the tumor phenotypes. Importantly, the expression of Prx II was correlated with that of FoxM1 in HCC patients. The activation of extracellular signal-related kinase (ERK) pathway and the expression of FoxM1 and cyclin D1 were highly dependent on Prx II in H-ras(G12V)-HCC cells and H-ras(G12V)-Tg livers. Prx II is FoxM1-dependently-expressed antioxidant in HCC and function as an enhancer of Ras(G12V) oncogenic potential in hepatic tumorigenesis through activation of ERK/FoxM1/cyclin D1 cascade.

Lysophosphatidylcholine increases the neurotoxicity of Alzheimer's amyloid ß1-42 peptide: role of oligomer formation.

Oligomer formation is considered as a critical process for the neurotoxic effects of Alzheimer's amyloid ß (Aß) peptide. Previously we have demonstrated that lysophosphatidylcholine (LPC) increases the oligomer formation of Aß1-42, the major Aß peptide found Alzheimer's disease (AD) lesions. In this study, we have investigated whether LPC affects the neurotoxic effects of Aß1-42 in a neuronal cell line (A1) culture. Dimethyl thiazolyl diphenyl tetrazolium (MTT) assay revealed that up to 10µM concentration, LPC did not affect A1 cell viability. Aß1-42 decreased the cell viability, and such effect was dose dependently enhanced by LPC. However, neither LPC nor Aß1-42, alone or in combination increased lactate dehydrogenase (LDH) release from A1 cells after 24-h treatment. Terminal deoxynucleotidyl transferase dUTP-biotin nick-end-labeling (TUNEL) assay showed that LPC increased Aß1-42-induced apoptotic cell number. To determine the underlying mechanisms, the proteins implicated in apoptosis pathways including Bcl-2- and caspase-family were analyzed by Western blotting. The results demonstrated that Aß1-42 decreased Bcl-2 in A1 cells at 24h, whereas LPC had no effect at any time point. Both LPC and Aß1-42 increased Bax level at 24h, and their combined stimulation showed a synergistic effect. Similar synergistic effect of LPC and Aß1-42 on caspase9 activation was observed. Dot blot immunoassay and Western blotting showed that LPC augmented Aß1-42 oligomer formation in cell culture medium. Removing LPC-induced early-formed Aß1-42 oligomer from the culture medium by immunoprecipitation decreased active caspase9 level and neurotoxicity, as revealed by Western blotting and MTT assay. Furthermore, dihydroethidium (DHE) assay showed that Aß1-42 increased reactive oxygen species level in A1 cells, such effect was further enhanced by LPC. Thus, our results demonstrated that LPC increased the oligomer formation process of Aß1-42 peptide in culture condition, and consequently increased apoptotic neuronal death. Such process might be important for the pathogenesis of AD, and inhibition of LPC generation could be a therapeutic target for the disease.

Human neural stem cells expressing carboxyl esterase target and inhibit tumor growth of lung cancer brain metastases.

Neural stem cells (NSCs) led to the development of a novel strategy for delivering therapeutic genes to brain tumors. Human NSCs expressing rabbit carboxyl esterase (F3.CE), which activates CPT-11, significantly inhibit the growth of A549 human non-small cell lung adenocarcinoma cells in the presence of CPT-11 in vitro and in vivo. F3.CE cells migrated selectively into the brain metastases located in the opposite hemisphere. The treatment also significantly decreased tumor volume in immune-deficient mice bearing lung cancer when F3.CE cells were transplanted into the contralateral hemisphere. The survival of tumor-bearing animals was significantly prolonged by the treatment with F3.CE and CPT-11. This strategy could be considered as an effective treatment regimen for lung cancer brain metastases.

Neural stem cell-mediated CE/CPT-11 enzyme/prodrug therapy in transgenic mouse model of intracerebellar medulloblastoma.

Medulloblastoma is a heterogeneous diffuse neoplasm that can be highly disseminated, and is the most common malignant childhood brain tumor. Although multimodal treatments have improved survival rates for patients with medulloblastoma, these tumors are associated with high morbidity and mortality. New treatment strategies are urgently needed to improve cure rates and, importantly, to spare normal brain tissue from neurotoxicity and patients from life-long cognitive and functional deficits associated with current therapies. In numerous preclinical brain tumor models, neural stem cells (NSCs) have shown great promise as delivery vehicles for therapeutic genes. Here, we have used an established, genetically modified human NSC line (HB1.F3.CD) to deliver carboxylesterase (CE) to cerebellar tumor foci and locally activate the prodrug camptothecin-11 (CPT-11) (Irinotecan) to the potent topoisomerase I inhibitor SN-38. HB1.F3.CD NSC tumor tropism, intratumoral distribution and therapeutic efficacy were investigated in clinically relevant experimental models. Magnetic resonance imaging was used for in vivo tracking of iron nanoparticle-labeled NSCs, and to assess the therapeutic efficacy of CE-expressing HB1.F3.CD cells. As compared with controls, a significant decrease in tumor growth rate was seen in mice that received both NSCs and CPT-11 as their treatment regimen. Thus, this study provides proof-of-concept for NSC-mediated CE/CPT-11 treatment of medulloblastoma, and serves as a foundation for further studies toward potential clinical application.

Neural stem cell-based dual suicide gene delivery for metastatic brain tumors.

In our previous works, we demonstrated that human neural stem cells (NSCs) transduced with the cytosine deaminase (CD) gene showed remarkable 'bystander killer effect' on glioma and medulloblastoma cells after administration of the prodrug 5-fluorocytosine (5-FC). In addition, herpes simplex virus thymidine kinase (TK) is a widely studied enzyme used for suicide gene strategies, for which the prodrug is ganciclovir (GCV). To apply this strategy to brain metastasis treatment, we established here a human NSC line (F3.CD-TK) expressing the dual suicide genes CD and TK. We examined whether F3.CD-TK cells intensified the antitumor effect on lung cancer brain metastases. In vitro studies showed that F3.CD-TK cells exerted a marked bystander effect on human lung cancer cells after treatment with 5-FC and GCV. In a novel experimental brain metastases model, intravenously administered F3 cells migrated near lung cancer metastatic lesions, which were induced by the injection of lung cancer cells via the intracarotid artery. More importantly, F3.CD-TK cells in the presence of prodrugs 5-FC and GCV decreased tumor size and considerably prolonged animal survival. The results of the present study indicate that the dual suicide gene-engineered, NSC-based treatment strategy might offer a new promising therapeutic modality for brain metastases.

Synergistic effects of genetically engineered stem cells expressing cytosine deaminase and interferon-ß via their tumor tropism to selectively target human hepatocarcinoma cells.

Stem cells have received a great deal of attention for their clinical and therapeutic potential for treating human diseases and disorders. Recent studies have shown that it is possible to genetically engineered stem cells (GESTECs) to produce suicide enzymes that convert non-toxic prodrugs to toxic metabolites, selectively migrate toward tumor sites and reduce tumor growth. In this study, we evaluated whether these GESTECs are capable of migrating to hepatocarcinoma cells and examined the potential therapeutic efficacy of gene-directed enzyme prodrug therapy against liver cancer cells in cellular and animal models. A modified transwell migration assay was performed to determine the migratory capacity of GESTECs to Hep3B hepatocarcinoma cells. GESTECs, that is, HB1.F3.CD or HB1.F3.CD.interferon-ß (IFN-ß) cells, engineered to express a suicide gene, cytosine deaminase (CD), selectively migrated toward liver cancer cells. Treatment of Hep3B, human liver cancer cells, with the prodrug 5-fluorocytosine (5-FC) in the presence of HB1.F3.CD or HB1.F3.CD.IFN-ß cells resulted in the inhibition of Hep3B cell growth. In a xenografted mouse model injected with hepatocarcinoma, we investigated the therapeutic effect of these stem cells. For 9 weeks, the xenografted mice were treated with HB1.F3.CD or HB1.F3.CD.IFN-ß in the presence of 5-FC. A growth of tumor mass was inhibited about 40-50% in the mice treated with GESTECs and a prodrug. In addition, we further confirmed the cytotoxic effect on tumor cells by histological analysis and migratory effect of therapeutic stem cells. Taken together, GESTECs expressing a fusion gene encoding CD and IFN-ß may exert a synergistic antitumor effect on this type of tumor.

Potential antitumor therapeutic strategies of human amniotic membrane and amniotic fluid-derived stem cells.

As stem cells are capable of self-renewal and can generate differentiated progenies for organ development, they are considered as potential source for regenerative medicine and tissue replacement after injury or disease. Along with this capacity, stem cells have the therapeutic potential for treating human diseases including cancers. According to the origins, stem cells are broadly classified into two types: embryonic stem cells (ESCs) and adult stem cells. In terms of differentiation potential, ESCs are pluripotent and adult stem cells are multipotent. Amnion, which is a membranous sac that contains the fetus and amniotic fluid and functions in protecting the developing embryo during gestation, is another stem cell source. Amnion-derived stem cells are classified as human amniotic membrane-derived epithelial stem cells, human amniotic membrane-derived mesenchymal stem cells and human amniotic fluid-derived stem cells. They are in an intermediate stage between pluripotent ESCs and lineage-restricted adult stem cells, non-tumorigenic, and contribute to low immunogenicity and anti-inflammation. Furthermore, they are easily available and do not cause any controversial issues in their recovery and applications. Not only are amnion-derived stem cells applicable in regenerative medicine, they have anticancer capacity. In non-engineered stem cells transplantation strategies, amnion-derived stem cells effectively target the tumor and suppressed the tumor growth by expressing cytotoxic cytokines. Additionally, they also have a potential as novel delivery vehicles transferring therapeutic genes to the cancer formation sites in gene-directed enzyme/prodrug combination therapy. Owing to their own advantageous properties, amnion-derived stem cells are emerging as a new candidate in anticancer therapy.

Radiological response predicts survival following transarterial chemoembolisation in patients with unresectable hepatocellular carcinoma.

BACKGROUND: It remains unclear whether initial compact lipiodol uptake after transarterial chemoembolisation (TACE) is associated with improved survival in patients with hepatocellular carcinoma (HCC). AIM: To reveal the clinical relevance of compact lipiodolisation after TACE. METHODS: We studied 490 patients with unresectable HCC who had first been treated with TACE. Compact lipiodolisation was defined as the absence of an arterial enhancing lesion, reflecting complete lipiodol uptake, as assessed by dynamic computed tomography (CT) 1 month after treatment. The rate of initial compact lipiodolisation was analysed according to multiplicity and size of tumour, and survival of patients who achieved compact lipiodolisation was compared to that of patients who did not. RESULTS: Of the 490 patients, 409 (83.5%) were in Child-Pugh class A and 81 (16.5%) in class B. The rate of initial compact lipiodolisation in single HCCs was higher than that in multinodular HCCs (33.7% vs. 14.6%, P < 0.001). Among single HCCs, the rate of compact lipiodolisation in tumours ≤5, 5-10 and >10 cm was 46.6%, 13.6%, and 0% respectively. The 1-, 3- and 5-year survival rates of patients with compact uptake were 92.7%, 70.7% and 52.4% compared to 60.8%, 28.0% and 16.9% in patients with noncompact lipiodolisation. Multivariate analysis revealed that Child-Pugh class, alpha-fetoprotein level, tumour node metastasis stage, portal vein thrombosis and initial compact lipiodolisation were independent predictors of survival. CONCLUSIONS: Initial compact lipiodol uptake after transarterial chemoembolisation is associated with improved survival in patients with unresectable hepatocellular carcinoma. Accordingly, initial complete lipiodolisation should be considered a relevant therapeutic target.

Human amniotic fluid-derived stem cells expressing cytosine deaminase and thymidine kinase inhibits the growth of breast cancer cells in cellular and xenograft mouse models.

As human amniotic fluid-derived stem cells (hAFSCs) are capable of multiple lineage differentiation, extensive self-renewal and tumor targeting, they may be valuable for clinical anticancer therapies. In this study, we used hAFSCs as vehicles for targeted delivery of therapeutic suicide genes to breast cancer cells. hAFSCs were engineered to produce AF2.CD-TK cells in order to express two suicide genes encoding bacterial cytosine deaminase (CD) and herpes simplex virus thymidine kinase (HSV-TK) that convert non-toxic prodrugs, 5-fluorocytosine (5-FC) and mono-phosphorylate ganciclovir (GCV-MP), into cytotoxic metabolites, 5-fluorouracil (5-FU) and triphosphate ganciclovir (GCV-TP), respectively. In cell viability test in vitro, AF2.CD-TK cells inhibited the growth of MDA-MB-231 human breast cancer cells in the presence of the 5-FC or GCV prodrugs, or a combination of these two reagents. When the mixture of 5-FC and GCV was treated together, an additive cytotoxic effect was observed in the cell viability. In animal experiments using female BALB/c nude mouse xenografts, which developed by injecting MDA-MB-231 cells, treatment with AF2.CD-TK cells in the presence of 5-FC and GCV significantly reduced tumor volume and weight to the same extent seen in the mice treated with 5-FU. Histopathological and fluorescent staining assays further showed that AF2.CD-TK cells were located exactly at the site of tumor formation. Furthermore, breast tissues treated with AF2.CD-TK cells and two prodrugs maintained their normal structures (for example, the epidermis and reticular layers) while breast tissue structures in 5-FU-treated mice were almost destroyed by the potent cytotoxicity of the drug. Taken together, these results indicate that AF2.CD-TK cells can serve as excellent vehicles in a novel therapeutic cell-based gene-directed prodrug system to selectively target breast malignancies.

Therapeutic targeting of subdural medulloblastomas using human neural stem cells expressing carboxylesterase.

The prognosis of medulloblastoma has improved significantly because of advances in multi-modal treatments; however, metastasis remains one of the prognostic factors for a poor outcome and is usually associated with tumor recurrence. We evaluated the migratory potential and therapeutic efficacy of genetically engineered human neural stem cells (NSCs) that encode a prodrug enzyme in the subdural medulloblastoma model. We genetically modified HB1.F3 (F3) immortalized human NSCs to express rabbit carboxylesterase (rCE) enzyme, which efficiently converts the prodrug CPT-11 (Irinotecan) into an active anti-cancer agent (SN-38). To simulate clinical metastatic medulloblastomas, we implanted human medulloblastoma cells into the subdural spaces of nude mice. rCE expressing NSCs (F3.rCE) were labeled with fluorescence magnetic nanoparticle for in vivo imaging. The therapeutic potential of F3.rCE was confirmed using a mouse subdural medulloblastoma model. The majority of intravenously (i.v.) injected, F3.rCE cells migrated to the subdural medulloblastoma site and a small number of F3.rCE cells were found in the lungs, pancreas, kidney and liver. Animals that received F3.rCE cells in combination with prodrug CPT-11 survived significantly longer (median survival: 142 days) than control mice that received F3.rCE cells only (median survival: 80 days, P<0.001) or CPT-11 only (median survival: 118 days, P<0.001). In conclusion, i.v. injected F3.rCE NSCs were able to target subdural medulloblastomas and demonstrate therapeutic efficacy. Our study provides data that supports further investigation of stem-cell-based gene therapy against metastatic medulloblastomas.

Factors that affect the diagnostic accuracy of liver fibrosis measurement by Fibroscan in patients with chronic hepatitis B.

BACKGROUND: Interquartile range/median value (IQR/M) of liver stiffness measurement (LSM) is a factor in chronic hepatitis C (CHC) leading to over estimation of fibrosis by Fibroscan. AIM: To investigate factors that affect the accuracy of LSM in chronic hepatitis B (CHB). METHODS: One hundred and ninety-nine patients were enrolled. Only procedures yielding > or =10 valid measurements were considered reliable. Liver fibrosis was evaluated using the Batts and Ludwig system. Liver biopsy (LB) specimens <15 mm were considered ineligible. RESULTS: The mean age (142 men and 57 women) was 40.1 years. A significant discordance (discordance of at least two stages between LB and LSM) was identified in 38 (19.1%) and 47 (23.6%) patients respectively, according to Marcellin et al. and Chan et al.'s cutoff values. In multivariate analyses, BMI and fibrosis stage (F0-2 vs. F3-4) were identified as independent predictors for significant discordance (P = 0.040; hazard ratio [HR], 1.126; 95% confidence interval [CI], 1.005-1.261 and P = 0.036; HR, 0.450; 95% CI, 0.213-0.949 respectively) with Marcellin et al.'s cutoffs, whereas fibrosis stage was the only independent predictor (P = 0.004; HR, 0.300; 95% CI, 0.131-0.685) with Chan's cutoffs. CONCLUSIONS: Success rate and IQR/M were not predictive factors of the accuracy for diagnosing liver fibrosis by Fibroscan in CHB. Fibrosis stage (F0-2) was the only factor to predict significant discordance between LB and LSM.

Human neural stem cells transduced with IFN-beta and cytosine deaminase genes intensify bystander effect in experimental glioma.

Previously, we have shown that the genetically modified human neural stem cells (NSCs) show remarkable migratory and tumor-tropic capability to track down brain tumor cells and deliver therapeutic agents with significant therapeutic benefit. Human NSCs that were retrovirally transduced with cytosine deaminase (CD) gene showed remarkable 'bystander killer effect' on the glioma cells after application of the prodrug, 5-fluorocytosine (5-FC). Interferon-beta (IFN-beta) is known for its antiproliferative effects in a variety of cancers. In our pilot clinical trial in glioma, the IFN-beta gene has shown potent antitumor activity in patients with malignant glioma. In the present study, we sought to examine whether human NSCs genetically modified to express both CD and IFN-beta genes intensified antitumor effect on experimental glioma. In vitro studies showed that CD/IFN-beta-expressing NSCs exerted a remarkable bystander effect on human glioma cells after the application of 5-FC, as compared with parental NSCs and CD-expressing NSCs. In animal models with human glioma orthotopic xenograft, intravenously infused CD/IFN-beta-expressing NSCs produced striking antitumor effect after administration of the prodrug 5-FC. Furthermore, the same gene therapy regimen prolonged survival periods significantly in the experimental animals. The results of the present study indicate that the multimodal NSC-based treatment strategy might have therapeutic potential against gliomas.

GNB3 C825T polymorphism and elevated blood pressure.

Unlike in Europeans and Africans, the relationship between the human guanine nucleotide binding beta polypeptide 3 (GNB3) C825T gene polymorphism (rs5443) and blood pressures is inconsistent in Asians. The aim of the study was to investigate whether the GNB3 genotype demonstrates different associations with resting blood pressure and body fatness across cardio/respiratory fitness (CRF) levels. A total of 727 Korean women aged 31-60 years (mean, 47.8+/-5.4 years) participated in the study. In subgroup analyses of the obese group, TT individuals had significantly higher values of body weight than CC and CT individuals (p=0.006 and p=0.006, respectively) and body mass index (BMI) (p=0.002 and p=0.011, respectively). TT and CT individuals also tended to have higher CRF values than CC individuals. Regression analyses showed that the association between GNB3 genotype and resting blood pressure remained significant after adjustment for age and menopause, but was not significant after additional adjustment for body fatness. In summary, the findings of this study suggest that body fatness and CRF might modify the GNB3-mediated genetic susceptibility to elevated resting blood pressures in middle-aged Korean women.

Intrathecal transplantation of human neural stem cells overexpressing VEGF provide behavioral improvement, disease onset delay and survival extension in transgenic ALS mice.

Amyotrophic lateral sclerosis (ALS) is the most common adult onset motoneuron disease. The etiology and precise pathogenic mechanisms of the disease remain unknown, and there is no effective treatment. Vascular endothelial growth factor (VEGF) has recently been shown to exert direct neurotrophic and neuroprotective effects in animal models of ALS. Here we show that intrathecal transplantation of immortalized human neural stem cells (NSCs) overexpressing human VEGF gene (HB1.F3.VEGF) significantly delayed disease onset and prolonged the survival of the SOD1G93A mouse model of ALS. At 4 weeks, post-transplantation grafted cells were found within the gray matter of the spinal cord. Furthermore, transplanted F3.VEGF cells that express neuronal phenotype (MAP2+) were found in the anterior horn of the spinal cord gray matter indicating that the transplanted human NSCs migrated into the gray matter, took the correct structural position, integrated into the spinal cord anterior horn and differentiated into motoneurons. Intrathecal transplantation of F3.VEGF cells provides a neuroprotective effect in the diseased spinal cord by concomitant downregulation of proapoptotic proteins and upregulation of antiapoptotic proteins. Our results suggest that this treatment modality of intrathecal transplantation of human NSCs genetically modified to overexpress neurotrophic factor(s) might be of value in the treatment of ALS patients without significant adverse effects.

Physical activity and metabolic syndrome in Korean children.

Little is known about whether lifestyle factors such as dietary intake, physical activity (PA), and cardio/respiratory fitness (CRF) are associated with metabolic risk factors in Korean children. The purpose of the study was to investigate the relationships among those lifestyle-related modifiable factors and the clustering of metabolic risk factors in young Korean children. In a cross-sectional study, we studied 246 Korean children (mean+/-SD; age: 12.6+/-0.5 years, BMI: 19.9+/-3.2 kg/m (2)) who were recruited from local elementary schools. In the total study population, physical activity and CRF were inversely associated with metabolic risk factors including body fatness, blood pressures, blood lipids and glucose. Daily caloric intake and proportion of carbohydrates were positively associated with BMI and percent body fat only. Multivariate regression analyses showed that physical activity was independently and inversely associated with the clustering of metabolic risk factors, even after adjustments for age, sex, sexual maturation, dietary intake, and CRF. Overall, the current findings of the study suggest that physical activity rather than CRF and/or dietary intake is an independent predictor for the clustering of metabolic risk factors in Korean children.

Human neural stem cells overexpressing glial cell line-derived neurotrophic factor in experimental cerebral hemorrhage.

Recent studies have reported that glial cell line-derived growth factor (GDNF) has neurotrophic effects on the central nervous system, and the neural stem cells (NSCs) engrafted in animal models of stroke survive and ameliorate the neurological deficits. In this study, a stable human NSC line overexpressing GDNF (F3.GDNF) was transplanted next to the intracerebral hemorrhage (ICH) lesion site and a possible therapeutic effect was investigated. F3.GDNF human NSC line was transplanted into the cortex overlying the striatal ICH lesion. ICH was induced in adult mice by the unilateral injection of bacterial collagenase into the striatum. The animals were evaluated for 8 weeks with rotarod and limb placement tests. Transplanted NSCs were detected by beta-gal immunostaining with double labeling of neurofilament, microtubule associated protein-2, glial fibrillary acidic protein or human nuclear matrix antigen (HuNuMA). F3.GDNF human NSCs produced a four times higher amount of GDNF over parental F3 cells in vitro, induced behavioral improvement in ICH mice after brain transplantation and two- to threefold increase in cell survival of transplanted NSCs at 2 and 8 weeks post-transplantation. In F3.GDNF-grafted ICH brain, a significant increase in the antiapoptotic protein and cell survival signal molecules, and a marked reduction in proapoptotic proteins were found as compared with control group. Brain transplantation of human NSCs overexpressing GDNF in ICH animals provided functional recovery in ICH animals, and survival and differentiation of grafted human NSCs. These results indicate that the F3.GDNF human NSCs should be of a great value as a cellular source for the cellular therapy in animal models of human neurological disorders including ICH.

Cystatin C expression in ischemic white matter lesions.

OBJECTIVES: To study the involvement of cystatin C in the progression of ischemic white matter lesions (WMLs). MATERIALS AND METHODS: Cystatin C levels in the cerebrospinal fluid (CSF) of patients with cerebrovascular disease, and also in primary and established human neural cell cultures were investigated. For pathologic analysis, cystatin C immunoreactivity was investigated in the white matter of patients with severe WMLs, mild WMLs or controls. RESULTS: Cystatin C levels in the CSF of patients with Fazekas WML grade 3 [14 with hypertension; W/HT(+) and nine without hypertension; W/HT(-)] were lower than those in 38 patients with grade 0-1 (P = 0.0022 and P < 0.0001 respectively). Immunohistochemical study showed that the cystatin C immunoreactivity was found in astrocytes, and the number of astrocytes in the white matter in the severe WML group was decreased when compared with that in controls (P = 0.0027) and in the mild WML group (P = 0.0024). In human neural cell cultures, treatments with thrombin, matrix metalloproteinases and interleukin 1 beta increased the expression of cystatin C mRNA in human astrocytes and hybrid neurons, but an enzyme-linked immunosorbent assay revealed that only thrombin significantly increased the production and secretion of cystatin C in astrocytes. CONCLUSIONS: These results suggest that low levels of CSF cystatin C in ischemic WMLs might be due to the decreased number of astrocytes that secrete cystatin C in response to the stimuli of proteases and inflammatory cytokines.

Human neural stem cells target and deliver therapeutic gene to experimental leptomeningeal medulloblastoma.

Medulloblastomas are highly malignant neuroectodermal cerebellar tumors of children. One of the reasons for the difficulty for the treatment of medulloblastomas is their inherent tendency to metastasize through the cerebrospinal fluid (CSF) pathway leading to leptomeningeal dissemination. Recently, genetically modified neural stem cells (NSCs) were shown to have the capability of selectively migrating into glioma mass and delivering therapeutic agents with significant therapeutic benefits. In the present study, we applied the NSC strategy to target medulloblastomas, particularly their leptomeningeal dissemination. We used NSCs that were retrovirally transduced with the cytosine deaminase gene (CD-NSCs). In vitro studies demonstrated that CD-NSCs had sufficient migratory activity toward medulloblastoma cells and exerted a remarkable bystander effect on these cells following the application of 5-fluorocytosine (5-FC). It is noteworthy that neutralization of the hepatocyte growth factor blocked their migration In animal studies using our leptomeningeal dissemination model, CD-NSCs implanted directly into CSF space were shown to distribute diffusely within the disseminated tumor cells and could provide remarkable antitumor effect after intraperitoneal administration of 5-FC. Furthermore, CD-NSC treatment followed by 5-FC administration prolonged survival periods significantly in experimental animals. Our data suggest that the CD-NSC strategy can also be applied to target leptomeningeal dissemination of medulloblastomas.

Potential differentiation of human mesenchymal stem cell transplanted in rat corpus cavernosum toward endothelial or smooth muscle cells.

One of the causes of erectile dysfunction (ED) is the damaged penile cavernous smooth muscle cells (SMCs) and sinus endothelial cells (ECs). To investigate the feasibility of applying immortalized human mesenchymal stem cells (MSCs) to penile cavernous ECs or SMCs repair in the treatment of ED, the in vivo potential differentiation of the immortalized human MSCs toward penile cavernous endothelial or smooth muscle was investigated. One clone of immortalized human bone marrow mesenchymal stem cell line B10 cells via retroviral vector encoding v-myc were transplanted into the cavernosum of the Sprague-Dawley rats and harvested 2 weeks later. The expression of CD31, von Willebrand factor (vWF), smooth muscle cell actin (SMA), calponin and desmin was determined immunohistochemically in rat penile cavernosum. Multipotency of B10 to adipogenic, osteogenic or chondrogenic differentiation was found. Expression of EC specific markers (CD31 or vWF protein) and expression of SMC specific markers (calponin, SMA or desmin protein) were demonstrated in grafted B10 cells. When human MSCs were transplanted into the penile cavernosum, they have the potential to differentiate toward ECs or SMCs. Human MSCs may be a good candidate in the treatment of penile cavernosum injury.