GRIK1 promotes glioblastoma malignancy and is a novel prognostic factor of poor prognosis.

Primary tumors of the central nervous system (CNS) are classified into over 100 different histological types. The most common type of glioma is derived from astrocytes, and the most invasive glioblastoma (WHO IV) accounts for over 57% of these tumors. Glioblastoma (GBM) is the most common and fatal tumor of the CNS, with strong growth and invasion capabilities, which makes complete surgical resection almost impossible. Despite various treatment methods such as surgery, radiotherapy, and chemotherapy, glioma is still an incurable disease, and the median survival time of patients with GBM is shorter than 15 months. Thus, molecular mechanisms of GBM characteristic invasive growth need to be clarified to improve the poor prognosis. Glutamate ionotropic receptor kainate type subunit 1 (GRIK1) is essential for brain function and is involved in many mental and neurological diseases. However, GRIK1's pathogenic roles and mechanisms in GBM are still unknown. Single-nuclear RNA sequencing of primary and recurrent GBM samples revealed that GRIK1 expression was noticeably higher in the recurrent samples. Moreover, immunohistochemical staining of an array of GBM samples showed that high levels of GRIK1 correlated with poor prognosis of GBM, consistent with The Cancer Genome Atlas database. Knockdown of GRIK1 retarded GBM cells growth, migration, and invasion. Taken together, these findings show that GRIK1 is a unique and important component in the development of GBM and may be considered as a biomarker for the diagnosis and therapy in individuals with GBM.

Effect of information encounter on concerns over healthy eating- mediated through body comparison and moderated by body mass index or body satisfaction.

BACKGROUND: Understanding factors that influence healthy or unhealthy eating can inform intervention strategies. This study ascertained whether and how unintentional exposure to food and nutrition information influenced healthy eating concerns. The study tested body comparison, body satisfaction, and body mass index as three mechanisms that potentially link food information encounter, commonly known as information scanning, to healthy eating concerns. METHODS: A sample of 440 online participants (mean age = 29.15 years) was used to investigate: (1) how unintentional exposure to food and nutrition information, i.e., information encounter (IE), affects healthy eating concerns (HEC); (2) how the effect of IE on HEC is mediated by body comparison (BC); (3) how the paths of the mediation model are moderated by body satisfaction (BS) or body mass index (BMI). RESULTS: The findings show a positive and sizable total effect of IE on HEC - a whole-scale increase in information encounter is associated with a substantial increase in healthy eating concerns by 15 percentage points (bp = 0.150). BC is found to mediate the effect of IE on HEC in an all-positive complementary mediation. Both the indirect and the direct-and-remainder paths show sizable effects. The mediated path contributes about 20% of the total effect between IE and HEC (cp = 20%), while the direct-and-remainder path contributes the rest (cp = 80%). BS was found to moderate the relationship between IE and BC, the first leg of the mediation. The moderation effect is large - the effect of IE on BC is much smaller on the highly and the moderately satisfied than on the lowly satisfied (slope differential bp = -.60). BMI was found to moderate the direct-and-remainder effect of IE on HEC, controlling BC. That is, the effect of IE on HEC, after filtering out the mediated effect through BC, is much larger for those with high or low BMI than those with healthy BMI (slope differential bp = .32). CONCLUSIONS: Exposure, even if unintentional, to food and nutrition information is an important predictor of HEC. BC, BS, and BMI are important factors that help to explain the process through which information affects behaviors.

Early outcomes of endoscopic endonasal approach pituitary adenomas resection with minimal nasal injury.

ABSTRACT: To report the results of a consecutive series of pituitary adenomas resected through endoscopic endonasal approach (EEA) with minimal nasal injury.Retrospectively review tumor characteristics and surgical outcomes of a consecutive series of EEA pituitary adenomas resection performed mainly by a single author between March 2018 and June 2019.A total of 75 endoscopic endonasal approach pituitary adenoma resections were performed by the authors' team. Of the 75 patients, 28 through mononostril EEA, 47 through Binonostril EEA. Hadad-Bassagasteguy vascularized nasoseptal flap was harvested in only 4 (5.3%) patients with a high risk of postoperative cerebrospinal fluid leak, and one side middle turbinate only been resected in 2 (2.7%) patients, other patients preserved bilateral middle turbinate. Of the 75 patients, gross total resection is 74.7%, near-total resection is 16.0%. Endocrinological remission was achieved in 76.9% of GH-secreting adenomas, 61.5% of prolactin-secreting adenomas. The postoperative cerebrospinal fluid leak rate was 2.7%. Two patients had suprasellar hemorrhage, 1 patient had perioperative stroke, 2 patients had permanent diabetes insipidus, no cranial nerve deficits, internal carotid artery injury, anosmia, and death. The sino-nasal function was measured with the Sino-Nasal Outcome Test-22 and visual analog scale for olfaction preoperatively and postoperatively, and there was no statistically significant difference.The EEA is an effective approach to resect pituitary adenomas, the gross total resection and near-total resection rate and endocrinological remission rate are satisfactory. The EEA is a safe approach, as the complication rate is acceptable compared with those reported in the previous series of microscopic and endoscopic approaches. These results can be achieved with minimal nasal injury.

Texture Analysis of High b-Value Diffusion-Weighted Imaging for Evaluating Consistency of Pituitary Macroadenomas.

BACKGROUND: Preoperative evaluation of the consistency of pituitary macroadenomas is important for neurosurgeons to prepare the surgical plan. PURPOSE: To evaluate the diagnostic performance of texture analysis (TA) of diffusion-weighted imaging (DWI) at a standard b-value (b = 1000 s/mm2 ) and a high b-value (b = 2000 s/mm2 ) for their ability to assess the tumor consistency of pituitary macroadenomas. STUDY TYPE: Retrospective. POPULATION/SUBJECTS: Fifty patients with histologically confirmed pituitary macroadenomas were classified as soft (n = 37) or hard (n = 13) types. FIELD STRENGTH/SEQUENCE: Coronal T2 -weighted imaging (T2 WI), Readout Segmentation of Long Variable Echo-trains (RESOLVE) DWI at b = 1000 s/mm2 and b = 2000 s/mm2 were acquired with 3.0T MRI. ASSESSMENT: The corresponding apparent diffusion coefficient (ADC) maps (ADC1000 and ADC2000 ) were registered to T2 WI. Regions of interest (ROIs) were manually drawn along the solid part of the tumor from the coregistered T2 WI-ADC images. The texture parameters from T2 WI, ADC1000 , and ADC2000 were acquired. STATISTICAL TESTS: The texture parameters were compared between the two types by using unpaired Student's t-test. Receiver operating characteristic (ROC) curves and logistic regression analyses were used to assess their diagnostic performance. RESULTS: Significant differences in TA parameters of ADC1000 and ADC2000 were observed between soft and hard types (P < 0.05 for all), whereas the TA of T2 WI resulted in no significant difference (P > 0.05 for all). TA of ADC2000 provided a superior diagnostic performance compared with that of ADC1000 (P = 0.038). A combination of mean value and entropy of ADC2000 yielded an AUC, a sensitivity, and a specificity of 0.911, 78.4% and 92.3%, respectively. DATA CONCLUSION: TA of ADC values were useful for assessing the tumor consistency of pituitary macroadenomas. ADC2000 may facilitate better type discrimination. LEVEL OF EVIDENCE: 3 Technical Efficacy Stage: 2 J. Magn. Reson. Imaging 2020;51:1507-1513.

Association Between Champagne Bottle Neck Sign of Internal Carotid Artery and Ipsilateral Hemorrhagic Stroke in Patients with Moyamoya Disease.

OBJECTIVE: To assess association between champagne bottle neck sign (CBNS) in carotid artery and intracranial hemorrhage in patients with moyamoya disease (MMD). METHODS: This retrospective study included 76 consecutive patients with MMD without definite risk factors associated with intracranial hemorrhage who underwent preoperative angiography from January 2016 to December 2017. CBNS was defined as luminal diameter ratio of internal carotid artery/common carotid artery ≤0.5 on angiography. The right and left cerebral hemisphere in each patient was separately identified as hemorrhagic and nonhemorrhagic. Association between CBNS and intracranial hemorrhage was analyzed. RESULTS: Of 76 patients with MMD, intracranial hemorrhage was found in 44 of 152 (28.9%) hemispheres, and 6.8% (3/44) had multiple events. Comparing carotid arteries without intracranial hemorrhage in ipsilateral hemispheres, patients with intracranial hemorrhage in the ipsilateral hemisphere had significantly smaller luminal diameter ratio of internal carotid artery/common carotid artery (0.49 ± 0.11 vs. 0.55 ± 0.12, P < 0.01) and higher prevalence of CBNS (63.7% vs. 41.7%, P = 0.01). Comparing hemispheres with intracranial hemorrhage, patients with ipsilateral carotid artery CBNS had significantly higher prevalence of hemorrhage in posterior territories than patients without CBNS (57.1% vs. 23.1%, P = 0.05). Logistic regression revealed that CBNS was significantly associated with ipsilateral intracranial hemorrhage before (odds ratio = 2.45; 95% confidence interval, 1.19-5.05; P = 0.02) and after (odds ratio = 3.43; 95% confidence interval, 1.50-7.87; P < 0.01) adjusting for female sex, lenticulostriate anastomosis, and choroidal anastomosis. CONCLUSIONS: CBNS is significantly associated with intracranial hemorrhage in the ipsilateral hemisphere in patients with MMD, particularly intracranial hemorrhage in posterior territories.

MicroRNA-622 suppresses the proliferation of glioma cells by targeting YAP1.

It has recently been shown that miR-622 plays a tumor suppressive role in many human cancers. However, the exact function and underlying mechanism are still unknown. Here, we reported that the level of miR-622 is clearly reduced in human glioma tissues in comparison with normal brain tissues and is negatively correlated with the histological grades. Additionally, ectopically expressed miR-622 significantly inhibited cell proliferation and induced cell cycle arrest at the G0/G1 phase in glioma cells. Furthermore, the bioinformatics analysis revealed that YAP1 possesses putative miR-622-binding sites within its 3'UTR. Consequently, an elevated miR-622 level was found to suppress the luciferase reporter activity of YAP1 3'UTR, and the effect was diminished by the deletion of the miR-622 seed binding site. In addition, the level of YAP1 protein expression was significantly decreased after the overexpression of miR-622. These results indicate a negative link between miR-622 and YAP1 and further confirm that YAP1 is a direct target of miR-622, suggesting that miR-622 could be a new important therapeutic strategy for gliomas treatment.

MiR-184 Retarded the Proliferation, Invasiveness and Migration of Glioblastoma Cells by Repressing Stanniocalcin-2.

To investigate the repression of miR-184 on Stanniocalcin-2 (STC2) and how this axis affects the propagation, invasiveness and migration ability of glioblastoma cells. RT-PCR was employed to determine the miR-184 and STC2 mRNA expression both in tissues and cells. Western blot was employed to determine the protein expression levels. The cells were transfected via lipofection. MTT, colony formation, invasion and scratch healing assays were conducted to study the propagation, invasiveness and migratory ability of glioblastoma cells, respectively. The dual luciferase reporter gene assay was conducted to determine whether miR-184 could directly bind to STC2 mRNA 3'UTR. MiR-184 was under-expressed whereas STC2 was over-expressed in glioblastoma tissues and cell line. The up-regulation of miR-184 significantly suppressed the propagation, migratory ability and invasion of glioblastoma cells, whereas the over-expression of STC2 restored this effect. MiR-184 was confirmed to directly target STC2. MiR-184 could retard the propagation, invasiveness and migratory ability of glioblastoma cells by suppressing STC2.

miR-330-5p suppresses glioblastoma cell proliferation and invasiveness through targeting ITGA5.

The present study intended to investigate the biological effects of miR-330-5p on glioblastoma (GBM) cell proliferation and invasiveness by targeting integrin α5 (ITGA5). The expressions of miR-330-5p and ITGA5 mRNA in GBM cell lines (U87, U251, and U373) and normal brain glial cell line (HEB) were detected using RT-qPCR. Protein expression of ITGA5 was examined using Western blot. The present study used MTT assay, colony formation assay, Transwell assay, wound healing assay, and flow cytometry analysis in order to determine the biological functions of GBM cells (including cell proliferation, invasion, migration, apoptosis, and cell cycle). The present study applied dual-luciferase reporter gene assay to identify the target relationship between miR-330-5p and ITGA5. miR-330-5p was low-expressed in GBM cell lines while ITGA5 was high-expressed compared with HEB. miR-330-5p could directly target ITGA5 as well as suppress its expression in GBM cells. Up-regulation of miR-330-5p and down-regulation of ITGA5 both have an inhibitory effect on cell proliferation, invasion, and migration. Meanwhile, they could also promote GBM cell apoptosis. miR-330-5p could suppress proliferation and invasion of GBM cells through targeting ITGA5.

Endogenous neurotrophin-3 promotes neuronal sprouting from dorsal root ganglia.

In the present study, we investigated the role of endogenous neurotrophin-3 in nerve terminal sprouting 2 months after spinal cord dorsal root rhizotomy. The left L1-5 and L7-S2 dorsal root ganglia in adult cats were exposed and removed, preserving the L6 dorsal root ganglia. Neurotrophin-3 was mainly expressed in large neurons in the dorsal root ganglia and in some neurons in spinal lamina II. Two months after rhizotomy, the number of neurotrophin-3-positive neurons in the spared dorsal root ganglia and the density of neurite sprouts emerging from these ganglia were increased. Intraperitoneal injection of an antibody against neurotrophin-3 decreased the density of neurite sprouts. These findings suggest that endogenous neurotrophin-3 is involved in spinal cord plasticity and regeneration, and that it promotes axonal sprouting from the dorsal root ganglia after spinal cord dorsal root rhizotomy.

Effect of glycyrrhizin on traumatic brain injury in rats and its mechanism.

OBJECTIVE: To investigate the neuroprotective effects of glycyrrhizin (Gly) as well as its effect on expression of high-mobility group box 1 (HMGB1) in rats after traumatic brain injury (TBI). METHODS: Male Sprague-Dawley rats were randomly divided into three groups: sham group, TBI group, and TBI+Gly group (n=36 per group). Rat TBI model was made by using the modified Feeney's method. In TBI+Gly group, Gly was administered intravenously at a dosage of 10 mg/kg 30 min after TBI. At 24 h after TBI, motor function and brain water content were evaluated. Meanwhile, HMGB1/HMGB1 receptors including toll-like receptor 4 (TLR4) and receptor for advanced glycation end products (RAGE)/nuclear factor-κB(NF-κB) signaling pathway and inflammatory cytokines in the injured brain tissues were detected using quantitative real-time polymerase chain reaction, western blot, electrophoretic mobility shift assay and enzyme-linked immunosorbent assay. Furthermore, HMGB1, RAGE and TLR4 immunohistochemistry and apoptosis were analyzed. RESULTS: Beam walking performance impairment and brain edema were significantly reduced in TBI+Gly group compared with TBI group; meanwhile, the over-expressions of HMGB1/HMGB1 receptors (TLR4 and RAGE)/NF-κB DNA-binding activity and inflammatory cytokines were inhibited. The percentages of HMGB1, RAGE and TLR4-positive cells and apoptotic cells were respectively 58.37% ± 5.06%, 54.15% ± 4.65%, 65.50% ± 4.83%, 52.02% ± 4.63% in TBI group and 39.99% ± 4.99%, 34.87% ± 5.02%, 43.33% ± 4.54%, 37.84% ± 5.16% in TBI+Gly group (all P<0.01 compared with TBI group). CONCLUSION: Gly can reduce secondary brain injury and improve outcomes in rat following TBI by down-regulation of HMGB1/HMGB1 receptors (TLR4 and RAGE)/NF-κB-mediated inflammatory responses in the injured rat brain.

Human herpesvirus 6 latent infection in patients with glioma.

The etiology of glioma remains unclear so far. Human herpesvirus 6 (HHV-6) might be associated with glioma, but there is no direct evidence to support this. High percentages of HHV-6 DNA and protein were detected in tissue from gliomas, compared with normal brain tissue. In addition, a strain of HHV-6A was isolated from the fluid specimens from glioma cysts. High levels of interleukin 6 (IL-6), interleukin 8 (IL-8), tumor necrosis factor α, and transforming growth factor ß (TGF-ß) were detected in the cyst fluid specimens from HHV-6-positive patients with glioma. Furthermore, HHV-6A infection promoted IL-6, IL-8, and TGF-ß production in astrocyte cultures. Our studies strongly suggest the involvement of HHV-6 infection in the pathogenesis of glioma.

The apoptosis-resistance in t-AUCB-treated glioblastoma cells depends on activation of Hsp27.

We previously reported that sEH inhibitor t-AUCB suppresses the growth of human glioblastoma U251 and U87 cell lines and induces cell-cycle G0/G1 phase arrest. In present study, we found even 96 h-treatment of 200 µM t-AUCB can not induce apoptosis in U251 and U87 cells. We also revealed that 200 µM t-AUCB significantly elevates the activation of p38 MAPK, MAPKAPK2 and Hsp27. The p38 MAPK inhibitor SB203580 and the inhibitor of Hsp27 phosphorylation, KRIBB3, were used to investigate the mechanism of the apoptosis-resistance. The results showed that, after blocking the activation of Hsp27 by SB203580 or KRIBB3, 200 µM t-AUCB significantly induces apoptosis and increases caspase-3 activities in U251 and U87 cells. Our data demonstrated that t-AUCB induces cell apoptosis after blocking itself-induced activation of Hsp27, and that the activation of Hsp27 may confer chemoresistance in GBM cells. The combination of t-AUCB and the inhibitor of Hsp27 phosphorylation may be a potential strategy for treatment of glioblastoma.

Anisomycin induces glioma cell death via down-regulation of PP2A catalytic subunit in vitro.

AIM: To examine the effects of anisomycin on glioma cells and the related mechanisms in vitro. METHODS: The U251 and U87 human glioblastoma cell lines were tested. The growth of the cells was analyzed using a CCK-8 cell viability assay. Apoptosis was detected using a flow cytometry assay. The expression of proteins and phosphorylated kinases was detected using Western blotting. RESULTS: Treatment of U251 and U87 cells with anisomycin (0.01-8 µmol/L) inhibited the cell growth in time- and concentration-dependent manners (the IC(50) values at 48 h were 0.233±0.021 and 0.192±0.018 µmol/L, respectively). Anisomycin (4 µmol/L) caused 21.5%±2.2% and 25.3%±3.1% of apoptosis proportion, respectively, in U251 and U87 cells. In the two cell lines, anisomycin (4 µmol/L) activated p38 MAPK and JNK, and inactivated ERK1/2. However, neither the p38 MAPK inhibitor SB203580 (10 µmol/L) nor the JNK inhibitor SP600125 (10 µmol/L) prevented anisomycin-induced cell death. On the other hand, anisomycin (4 µmol/L) reduced the level of PP2A/C subunit (catalytic subunit) in a time-dependent manner in the two cell lines. Treatment of the two cell lines with the PP2A inhibitor okadaic acid (100 nmol/L) caused marked cell death. CONCLUSION: Anisomycin induces glioma cell death via down-regulation of PP2A catalytic subunit. The regulation of PP2A/C exression by anisomycin provides a clue to further study on its role in glioma therapy.

A novel embolic stroke model resembling lacunar infarction following proximal middle cerebral artery occlusion in beagle dogs.

It is estimated that lacunar infarcts account for 25% of all ischemic strokes, but its exact etiology is still on debating. The existing controversies include whether the embolisms can indeed cause lacunar stroke in humans or animal models. We hypothesized that lacunar infarction can be induced by the proximal middle cerebral artery (MCA) segmental occlusion involving the orifices of lenticulostriate arteries in animal models, which have abundant distal cerebral collateral anastomosis. Our work here establishes a proximal MCA occlusion model using thrombi (autologous blood clots about 1.7 mm in diameter and 5 mm in length) in 8 beagle dogs, evaluates the progression of ischemic lesions at 30 min interval within 6 h after embolization using the diffusion weighted imaging (DWI), and discusses the potential mechanisms of lacunar infarction. Our results indicate that the left proximal MCAs can be successfully occluded in all dogs using interventional single-thrombus method. The small solitary or multiple ischemic lesions shown in DWI were observed in the deep brain area, with the mean detecting time of 1.21 ± 0.45 h using DWI and diameter of 6.62 ± 0.60mm in 6h-DWI after procedure. In conclusion, our method established an ischemic model which can recapitulate the radiologic and histologic changes in lacunar infarcts, suggesting that emboli can cause lacunar infarcts in animal model.

t-AUCB, an improved sEH inhibitor, suppresses human glioblastoma cell growth by activating NF-κB-p65.

Although sEH inhibitors are well studied in inflammatory and cardiovascular diseases, their effects on gliomas are unclear. In this study, we investigated the effects of t-AUCB, a more potent and selective sEH inhibitor, on U251 and U87 human glioblastoma cell lines and the HepG2 human hepatocellular carcinoma cell line. Our results showed that t-AUCB efficiently inhibited sEH activities in all three cell lines (the inhibition rate was more than 80% in each) and suppressed U251 and U87 cell growth in a dose-dependent manner, but exhibited no cell growth inhibition on HepG2. We detected high levels of phosphorylated NF-κB-p65 (Ser536) in t-AUCB-treated U251 and U87 cells, and then found that the NF-κB inhibitor PDTC can completely abolish t-AUCB-induced growth inhibition. This indicated that t-AUCB suppresses U251 and U87 cell growth by activating NF-κB-p65. Moreover, we found that t-AUCB induces cell-cycle G0/G1 phase arrest by regulating Cyclin D1 mRNA and protein levels and CDC2 (Thr161) phosphorylation level. We propose to further test this promising reagent for its anti-glioma activity in clinical relevant orthotopic brain glioma models.

In vitro and in vivo evaluation of ribavirin and pleconaril antiviral activity against enterovirus 71 infection.

Enterovirus 71(EV71) causes recurring outbreaks of hand, foot and mouth disease and encephalitis leading to complications or death in young children. More effective antiviral drugs are needed to prevent or reduce EV71-related disease and complications. However, there are no standard models currently in use to evaluate activity against EV71 infection both in vitro and in vivo. In this study, the activity of ribavirin and pleconaril against EV71 infection was evaluated in two models. An in vitro EV71 infection model was developed in RD cells, and an in vivo EV71 infection model was applied. Ribavirin and pleconaril effectively increased the viability of infected cells. Pleconaril reduced the morbidity and mortality of one-day-old infected mice, but ribavirin did not protect the infected mice. In all, the results demonstrated that infected cells and infected mice can be used to evaluate antiviral activity of ribavirin and pleconaril against EV71 infection in vitro and in vivo.

Human herpesvirus 6A induces apoptosis of primary human fetal astrocytes via both caspase-dependent and -independent pathways.

BACKGROUND: Human herpesvirus 6 (HHV-6) is a T-lymphtropic and neurotropic virus that can infect various types of cells. Sequential studies reported that apoptosis of glia and neurons induced by HHV-6 might act a potential trigger for some central nervous system (CNS) diseases. HHV-6 is involved in the pathogenesis of encephalitis, multiple sclerosis (MS) and fatigue syndrome. However, the mechanisms responsible for the apoptosis of infected CNS cells induced by HHV-6 are poorly understood. In this study, we investigated the cell death processes of primary human fetal astrocytes (PHFAs) during productive HHV-6A infection and the underlying mechanisms. RESULTS: HHV-6A can cause productive infection in primary human fetal astrocytes. Annexin V-PI staining and electron microscopic analysis indicated that HHV-6A was an inducer of apoptosis. The cell death was associated with activation of caspase-3 and cleavage of poly (ADP-ribose) polymerase (PARP), which is known to be an important substrate for activated caspase-3. Caspase-8 and -9 were also significantly activated in HHV-6A-infected cells. Moreover, HHV-6A infection led to Bax up-regulation and Bcl-2 down-regulation. HHV-6A infection increased the release of Smac/Diablo, AIF and cytochrome c from mitochondria to cytosol, which induced apoptosis via the caspase-dependent and -independent pathways. In addition, we also found that anti-apoptotic factors such as IAPs and NF-κB decreased in HHV-6A infected PHFAs. CONCLUSION: This is the first demonstration of caspase-dependent and -independent apoptosis in HHV-6A-infected glial cells. These findings would be helpful in understanding the mechanisms of CNS diseases caused by HHV-6.

The effect of lentivirus-mediated TH and GDNF genetic engineering mesenchymal stem cells on Parkinson's disease rat model.

This study was designed to assess the potential therapeutic efficacy of gene-modified mesenchymal stem cells (MSCs), MSCs-TH and MSCs-GDNF, in PD rats. Fifty-nine PD rat models were divided into five groups and then the gene-modified MSCs were transplanted into the striatum of rats according to the design. Apomorphine-induced rotational behavior in rats was observed weekly; rats which received both MSCs-TH and MSCs-GDNF showed the most significant improvement compared with those in other groups (P < 0.01). Three weeks later, immunohistochemistry analysis found TH-positive cells and GDNF-positive cells in striatal. Eight weeks later, PD rats were killed. HPLC and ELISA results showed DA and GDNF content in striatum of rats which received both MSCs-TH, and MSCs-GDNF was considerably higher compared with those of other groups (P < 0.01),respectively. In conclusion, our results suggest that combined transplantation of MSCs expressing TH and GDNF can lead to remarkable therapeutic effects in a rat model of PD.

MicroRNA-181a sensitizes human malignant glioma U87MG cells to radiation by targeting Bcl-2.

Radiotherapy is widely used in cancer treatment and biological studies. Multiple mechanisms induced by radiation, especially changes of the expression profile of genes, lead to the disruption of cellular homeostasis. MicroRNAs (miRNAs) are important post-transcriptional gene regulators and play an important role in response to cellular stress. Here we investigated the profiles of miRNA expression following exposure to radiation and the possible role of miRNAs in the modulation of radiosensitivity in the glioblastoma multiform U87MG cell line. MiRNA expression profiles revealed a limited set of miRNAs with altered expression in U87MG cells in response to radiation treatment. MiR-181a, a member of miR-181 family, was one of the down-regulated miRNAs, whose expression was further validated by qRT-PCR. The target mRNAs of radiation-responsive miRNAs were predicted with a target prediction tool. Transiently overexpressed miR-181a significantly sensitized malignant glioma cells to radiation treatment concurrent with the down-regulation of the protein Bcl-2 (B cell lymphoma/lewkmia-2). It indicates that miR-181a may modulate radiosensitivity by targeting Bcl-2 in human malignant glioma cells. These data suggest that radiation can affect miRNA expression, which regulates the cellular response, and miR-181a could be a target for enhancing the effect of radiation treatment on malignant glioma cells.

Pharmacokinetics and the bystander effect in CD::UPRT/5-FC bi-gene therapy of glioma.

BACKGROUND: Cytosine deaminase (CD) converts 5-fluorocytosine (5-FC) to 5-fluorouracil (5-FU) in CD/5-FC gene therapy, 5-FU will be mostly converted into nontoxic beta-alanine without uracil phosphoribosyltransferase (UPRT). UPRT catalyzes the conversion of 5-FU to 5-fluorouridine monophosphate, which directly kills CD::UPRT-expressing cells and surrounding cells via the bystander effect. But the pharmacokinetics and the bystander effect of CD::UPRT/5-FC has not been verified in vivo and in vitro. Before the CD::UPRT/5-FC bi-gene therapy system is used in clinical trial, it is essential to monitor the transgene expression and function in vivo. Thus, we developed a preclinical tumor model to investigate the feasibility of using (19)F-magnetic resonance spectroscopy ((19)F-MRS) and optical imaging to measure non-invasive CD and UPRT expression and its bystander effect. METHODS: C6 and C6-CD::UPRT cells were cultured with 5-FC. The medium, cells and their mixture were analyzed by (19)F-MRS. Rats with intracranial xenografted encephalic C6-CD::UPRT glioma were injected intraperitoneally with 5-FC and their (19)F-MRS spectra recorded. Then the pharmacokinetics of 5-FC was proved. Mixtures of C6 and C6-CD::UPRT cells at different ratios were cultured with 5-FC and the cytotoxic efficacy and survival rate of cells recorded. To determine the mechanism of the bystander effect, the culture media from cell comprising 25% and 75% C6-CD::UPRT cells were examined by (19)F-MRS. A comparative study of mean was performed using analysis of variance (ANOVA). RESULTS: (19)F-MRS on samples from C6-CD::UPRT cells cultured with 5-FC showed three broad resonance signals corresponding to 5-FC, 5-FU and fluorinated nucleotides (F-Nuctd). For the C6 mixture, only the 5-FC peak was detected. In vivo serial (19)F-MRS spectra showed a strong 5-FC peak and a weak 5-FU peak at 20 minutes after 5-FC injection. The 5-FU concentration reached a maximum at about 50 minutes. The F-Nuctd signal appeared after about 1 hour, reached a maximum at around 160 minutes, and was detectable for several hours. At a 10% ratio of C6-CD::UPRT cells, the survival rate was (79.55 +/- 0.88)% (P < 0.01). As the C6-CD::UPRT ratio increased, the survival rate of the cells decreased. (19)F-MRS showed that the signals for 5-FU and F-Nuctd in the culture medium increased as the ratio of C6-CD::UPRT in the mixture increased. CONCLUSIONS: (19)F-MRS studies indicated that C6-CD::UPRT cells could effectively express CD and UPRT enzymes. The CD::UPRT/5-FC system showed an obvious bystander effect. This study demonstrated that CD::UPRT/5-FC gene therapy is suitable for 5-FC to F-Nuctd metabolism; and (19)F-MRS can monitor transferred CD::UPRT gene expression and catalysis of substrates noninvasively, dynamically and quantitatively.