Cathepsin D Inhibits Angiogenesis in Pituitary Neuroendocrine Tumors.

Prolactin and growth hormone can acquire anti-angiogenic properties after undergoing proteolytic cleavage by Cathepsin D and bone morphogenetic protein 1 (BMP-1) into fragments known as vasoinhibins. Little is known about the effect of vasoinhibins on angiogenesis through the involvement of key cleavage enzymes Cathepsin D and BMP-1 in pituitary neuroendocrine tumors (PitNETs, formerly pituitary adenomas). The purpose of this study was to investigate the mechanism of action of Cathepsin D and BMP-1 on angiogenesis in PitNETs compared with that of pro-angiogenic factors, including vascular endothelial growth factor (VEGF) and basic fibroblast growth factor-2 (FGF2). A total of 43 patients were enrolled in a retrospective analysis and 22 samples were suitable for RNA extraction, including 16 nonfunctional PitNETs and six somatotroph tumors. The mRNA and protein levels of Cathepsin D, BMP-1, VEGF, and FGF2 were compared with those of von Willebrand factor, which was assessed to determine the vascularization of PitNETs. Cathepsin D and FGF2 were significantly correlated with vascularization in PitNETs. Both Cathepsin D and FGF2 are highly involved in angiogenesis in PitNETs, although the effect of Cathepsin D as an anti-angiogenic factor is dominant over that of FGF2 as a pro-angiogenic factor.

MiR-134, epigenetically silenced in gliomas, could mitigate the malignant phenotype by targeting KRAS.

Gliomas are characterized by a malignant phenotype with proliferation, cell cycle arrest and invasion. To explore the biological consequences of epigenetically regulated miRNAs, we performed a microarray-based screening (whose expression was affected by 5-AZA treatment) followed by bisulfite sequencing validation. We found that miR-134 as an epigenetically regulated suppressor gene with prognostic value in gliomas. MicroRNA-134 was downregulated in high-grade gliomas, especially in GBM samples. Functional studies in vitro and in vivo in mouse models showed that overexpression of miR-134 was sufficient to reduce cell cycle arrest, cell proliferation and invasion. Target analysis and functional assays correlated the malignant phenotype with miR-134 target gene KRAS, an established upstream regulator of ERK and AKT pathways. Overall, our results highlighted a role for miR-134 in explaining the malignant phenotype of gliomas and suggested its relevance as a target to develop for early diagnostics and therapy.

Overexpression of Transforming Acidic Coiled Coil­Containing Protein 3 Reflects Malignant Characteristics and Poor Prognosis of Glioma.

Gliomas are malignant primary brain tumors with poor prognosis. Recently, research was indicative of a tight connection between tumor malignancy and genetic alterations. Here, we propose an oncogenic implication of transforming acidic coiled-coil-containing protein 3 (TACC3) in gliomas. By comprehensively analyzing the Chinese glioma genome atlas (CGGA) and publicly available data, we demonstrated that TACC3 were overexpressed along with glioma grade and served as an independent negative prognostic biomarker for glioma patients. Functions' annotations and gene sets' enrichment analysis suggested that TACC3 may participate in cell cycle, DNA repair, epithelium-mesenchymal transition and other tumor-related biological processes and molecular pathways. Patients with high TACC3 expression showed CD133⁺ stem cell properties, glioma plasticity and shorter overall survival time under chemo-/radio-therapy. Additionally, a TACC3 associated the miRNA-mRNA network was constructed based on in silico prediction and expression pattern, which provide a foundation for further detection of TACC3-miRNA-mRNA axis function. Collectively, our observations identify TACC3 as an oncogene of tumor malignancy, as well as a prognostic and motoring biomarker for glioma patients.

Signal Peptide Peptidase, Encoded by HM13, Contributes to Tumor Progression by Affecting EGFRvIII Secretion Profiles in Glioblastoma.

BACKGROUND AND AIMS: EGFRvIII is the most prevalent glioblastoma mutation, occurring in more than 25% of glioblastomas. EGFRvIII cells release microvesicles that contain proteins, miRNAs, and mRNAs that enhance the growth and survival of surrounding tumor cells. However, little is known about the maturation process and regulatory mechanisms of secreted vesicles in EGFRvIII cells. METHODS: Signal peptide peptidase (SPP) provides a fascinating mechanism for protein cleavage and subsequent dislocation in the endoplasmic reticulum transmembrane domain. RESULTS: In this study, we reported that SPP facilitates the secretion of cytokines in vitro and promotes tumor progression in mice. Human cytokine antibody arrays revealed that EGFRvIII secreted higher levels of cytokines, but these levels were significantly reduced following SPP knockdown, suggesting that cytokines in EGFRvIII secretion profiles play important roles in GBM development. Identical results were confirmed in intracellular maturation tracking of TGF-ß1 in mouse serum. Clinically, analyses of GBM patient data from the database revealed that HM13 expression was closely related to patient prognosis and survival, suggesting an influence by the secreted vesicles of EGFRvIII tumor cells. CONCLUSIONS: Collectively, our study identifies that SPP affects EGFRvIII secretion profiles and thus promotes tumor progression, providing further understanding of the formation of secreted vesicles and driving role of EGFRvIII in GBM.

Early VEGF inhibition attenuates blood-brain barrier disruption in ischemic rat brains by regulating the expression of MMPs.

Vascular endothelial growth factor (VEGF) inhibition has been demonstrated to be an effective strategy in preserving the integrity of the blood-brain barrier (BBB) in patients with acute ischemic stroke. Loss of the BBB is the key event associated with morbidity and mortality in these patients. However, the underlying mechanisms remain poorly understood. In the present study, the effects of VEGF inhibition and the possible mechanism that underlies acute cerebral ischemia in rats was investigated. Following the induction of transient middle cerebral artery occlusion for a 90­min period, either an anti­VEGF neutralizing antibody (RB­222; 5 or 10 µg), or IgG (control), was administered by intracerebroventricular injection at 1 h following reperfusion. Functional outcomes, BBB leakage, brain edema, microvessel numbers and the relative protein levels of VEGF, matrix metalloproteinase (MMP)-2, MMP-9, occludin and collagen-IV were then determined using neurological assessments, Evans Blue staining, brain water content, CD31 staining and western blotting. Treatment with RB­222 at a dose of 5 and 10 µg significantly improved neurological functional outcomes and diminished infarct size, BBB leakage and brain edema compared with the MCAO and IgG groups at 24 h following reperfusion; 10 µg RB­222 was more effective than a 5 µg dose of the antibody. In addition, RB­222 reduced the number of immature microvessels, which subsequently attenuated BBB permeability. RB­222 significantly repressed VEGF expression as well as decreased MMP­2 and MMP­9 expression. However, it enhanced occludin and collagen­IV levels in the ischemic rat brain compared with the MCAO and IgG groups. Taken together, the results indicate that early inhibition of VEGF may have significant potential against cerebral ischemia, partly by regulating the expression of MMPs.

CAMKK2, Regulated by Promoter Methylation, is a Prognostic Marker in Diffuse Gliomas.

AIMS: To explore the expression, methylation pattern, the prognostic value, and the biological consequences of CAMKK2 in gliomas. METHODS: The expression and methylation pattern of CAMKK2 was inferred and validated from mRNA expression profile (N = 866) and methylation profile (N = 426) of glioma tissue samples, and independent samples were used for further validation by IHC and pyrosequencing. To explore the function of CAMKK2 in gliomas, in vitro studies, colony formation assays and migration and invasion assays were performed. RESULTS: We found the upregulation of CAMKK2 in high-grade glioma samples was associated with promoter hypomethylation. An elevated expression of CAMKK2 was associated with worse prognosis. By in vitro assays, we demonstrated that CAMKK2 could promote cell migration, invasion, and proliferation. CONCLUSIONS: The expression level of CAMKK2 could be regulated by promoter methylation. CAMKK2 serves as a prognostic marker in gliomas and could be a potential therapeutic target in gliomas.

[Corrigendum] Activation of sonic hedgehog signaling enhances cell migration and invasion by induction of matrix metalloproteinase-2 and -9 via the phosphoinositide-3 kinase/AKT signaling pathway in glioblastoma.

Mol Med Rep 12: [Related article:] 6702­6710, 2015; DOI: 10.3892/mmr.2015.4229 After the publication of the article, it has been brought to the authors' attention by an interested reader that we had made an error regarding the presentation of certain data in the manuscript. The error relates to the presentation of Figs. 1 and 2 in the paper: The control panels for Fig. 1C [labelled 'cyclopamine (µM)'] and Figs. 2B and C [labelled 'rhSSH (µg/ml)'] were derived from the same image. The control U251 cells, featured in Fig. 1 and Figs. 2B and C, were treated without cyclopamine and rhSHH. Therefore, the U251 cells treated without cyclopamine and rhSHH were considered as a control group compared with U251 cells that were separately treated with cyclopamine or rhSHH, and these were photographed randomly. A new Fig. 2 is provided, which contains the correct data for the control panels for Figs. 2B and C.

Activation of sonic hedgehog signaling enhances cell migration and invasion by induction of matrix metalloproteinase-2 and -9 via the phosphoinositide-3 kinase/AKT signaling pathway in glioblastoma.

Aberrant hedgehog signaling contributes to the development of various malignancies, including glioblastoma (GBM). However, the potential mechanism of hedgehog signaling in GBM migration and invasion has remained to be elucidated. The present study showed that enhanced hedgehog signaling by recombinant human sonic hedgehog N­terminal peptide (rhSHH) promoted the adhesion, invasion and migration of GBM cells, accompanied by increases in mRNA and protein levels of matrix metalloproteinase­2 (MMP­2) and MMP­9. However, inhibition of hedgehog signaling with cyclopamine suppressed the adhesion, invasion and migration of GBM cells, accompanied by decreases in mRNA and protein levels of MMP­2 and ­9. Furthermore, it was found that MMP­2- and MMP­9-neutralizing antibodies or GAM6001 reversed the inductive effects of rhSHH on cell migration and invasion. In addition, enhanced hedgehog signaling by rhSHH increased AKT phosphorylation, whereas blockade of hedgehog signaling decreased AKT phosphorylations. Further experiments showed that LY294002, an inhibitor of phosphoinositide-3 kinase (PI3K), decreased rhSHH­induced upregulation of MMP­2 and ­9. Finally, the protein expression of glioblastoma-associated oncogene 1 was positively correlated with levels of phosphorylated AKT as well as protein expressions of MMP­2 and ­9 in GBM tissue samples. In conclusion, the present study indicated that the hedgehog pathway regulates GBM-cell migration and invasion by increasing MMP-2 and MMP-9 production via the PI3K/AKT pathway.

Epirubicin inhibits growth and alters the malignant phenotype of the U­87 glioma cell line.

Epirubicin, an anthracycline derivative, is one of the main line treatments for brain tumors. The aim of the present study was to verify that epirubicin alters the growth and morphological characteristics of U­87 glioma cells. In the present study, the effects of epirubicin were tested using cellular and biochemical assays, which demonstrated its anti­proliferative and cytotoxic effects, with an IC50 of 6.3 µM for the U­87 cell line, while rat normal neuronal cells were resistant to epirubicin. Epirubicin also reduced the secretion of matrix metalloproteinase­9 by 48 and 56% at concentrations of 2.5 and 5 µM, respectively. Exposure to epirubicin also diminished levels of vascular endothelial growth factor in U­87 cells. Furthermore, a cell migration assay showed a significant decrease in cell migration from 28 to 59% following exposure to 1 µM epirubicin. The present study demonstrated the cytotoxic, anti­proliferative and anti­migrative potential of epirubicin against glioma cells in vitro.

Disrupted topological organization of resting-state functional brain network in subcortical vascular mild cognitive impairment.

AIMS: Neuroimaging studies have demonstrated both structural and functional abnormalities in widespread brain regions in patients with subcortical vascular mild cognitive impairment (svMCI). However, whether and how these changes alter functional brain network organization remains largely unknown. METHODS: We recruited 21 patients with svMCI and 26 healthy control (HC) subjects who underwent resting-state functional magnetic resonance imaging scans. Graph theory-based network analyses were used to investigate alterations in the topological organization of functional brain networks. RESULTS: Compared with the HC individuals, the patients with svMCI showed disrupted global network topology with significantly increased path length and modularity. Modular structure was also impaired in the svMCI patients with a notable rearrangement of the executive control module, where the parietal regions were split out and grouped as a separate module. The svMCI patients also revealed deficits in the intra- and/or intermodule connectivity of several brain regions. Specifically, the within-module degree was decreased in the middle cingulate gyrus while it was increased in the left anterior insula, medial prefrontal cortex and cuneus. Additionally, increased intermodule connectivity was observed in the inferior and superior parietal gyrus, which was associated with worse cognitive performance in the svMCI patients. CONCLUSION: Together, our results indicate that svMCI patients exhibit dysregulation of the topological organization of functional brain networks, which has important implications for understanding the pathophysiological mechanism of svMCI.

All-trans retinoic acid impairs the vasculogenic mimicry formation ability of U87 stem-like cells through promoting differentiation.

The poor therapeutic effect of traditional antiangiogenic therapy on glioblastoma multiforme (GBM) may be attributed to vasculogenic mimicry (VM), which was previously reported to be promoted by cancer stem-like cells (SLCs). All-trans retinoic acid (ATRA), a potent reagent which drives differentiation, was reported to be able to eradicate cancer SLCs in certain malignancies. The aim of the present study was to investigate the effects of ATRA on the VM formation ability of U87 glioblastoma SLCs. The expression of cancer SLC markers CD133 and nestin was detected using immunocytochemistry in order to identify U87 SLCs. In addition, the differentiation of these SLCs was observed through detecting the expression of glial fibrillary acidic protein (GFAP), ß-tubulin III and galactosylceramidase (Galc) using immunofluorescent staining. The results showed that the expression levels of GFAP, ß-tubulin III and Galc were upregulated following treatment with ATRA in a dose-dependent manner. Furthermore, ATRA significantly reduced the proliferation, invasiveness, tube formation and vascular endothelial growth factor (VEGF) secretion of U87 SLCs. In conclusion, the VM formation ability of SLCs was found to be negatively correlated with differentiation. These results therefore suggested that ATRA may serve as a promising novel agent for the treatment of GBM due to its role in reducing VM formation.

RAB34 was a progression- and prognosis-associated biomarker in gliomas.

The objective of this study is to explore the expression pattern, prognostic value, and functional role of RAB34 in gliomas. RAB34 messenger RNA (mRNA) expression was evaluated from low grade to high grade in 220 glioma patients of the Chinese Glioma Genome Atlas (CGGA). We therefore analyzed RAB34 mRNA expression in two validated datasets. For detecting the protein expression level of RAB34, another 104 glioma tissues were stained by immunohistochemistry. Gene ontology (GO) analysis and gene set variation analysis (GSVA) were used for functional annotation of RAB34. The mRNA and protein expression levels of RAB34 were both related to glioma grade progression and were inversely correlated with overall survival (OS) in high-grade glioma patients. GO analysis and GSVA showed that RAB34 sets related to migration were significantly enriched in the cases with RAB34 high expression. Pearson correlation analysis identified that genes including MMP-11, HSPB1, IGFBP2, HSPA6, IGFBP5, and MMP19 were positively correlated with RAB34. The expression of RAB34 is related to glioma grade progression and confers a poor prognosis in high-grade glioma patients.

ß-elemene induces caspase-dependent apoptosis in human glioma cells in vitro through the upregulation of Bax and Fas/ FasL and downregulation of Bcl-2.

BACKGROUND: ß-elemene, extracted from herb medicine Curcuma wenyujin has potent anti-tumor effects in various cancer cell lines. However, the activity of ß-elemene against glioma cells remains unclear. In the present study, we assessed effects of ß-elemene on human glioma cells and explored the underlying mechanism. MATERIALS AND METHODS: Human glioma U87 cells were used. Cell proliferation was determined with MTT assay and colony formation assay to detect the effect of ß-elemene at different doses and times. Fluorescence microscopy was used to observe cell apoptosis with Hoechst 33258 staining and change of glioma apoptosis and cell cycling were analyzed by flow cytometry. Real-time quantitative PCR and Western-blotting assay were performed to investigated the influence of ß-elemene on expression levels of Fas/FasL, caspase-3, Bcl-2 and Bax. The experiment was divided into two groups: the blank control group and ß-elemne treatment group. RESULTS: With increase in the concentration of ß-elemene, cytotoxic effects were enhanced in the glioma cell line and the concentration of inhibited cell viability (IC50) was 48.5 µg/mL for 24h. ß-elemene could induce cell cycle arrest in the G0/G1 phase. With Hoechst 33258 staining, apoptotic nuclear morphological changes were observed. Activation of caspase-3,-8 and -9 was increased and the pro-apoptotic factors Fas/FasL and Bax were upregulated, while the anti-apoptotic Bcl-2 was downregulated after treatment with ß-elemene at both mRNA and protein levels. Furthermore, proliferation and colony formation by U87 cells were inhibited by ß-elemene in a time and does- dependent manner. CONCLUSIONS: Our results indicate that ß-elemene inhibits growth and induces apoptosis of human glioma cells in vitro. The induction of apoptosis appears to be related with the upregulation of Fas/FasL and Bax, activation of caspase-3,-8 and -9 and downregulation of Bcl-2, which then trigger major apoptotic cascades.

Curcumin suppresses malignant glioma cells growth and induces apoptosis by inhibition of SHH/GLI1 signaling pathway in vitro and vivo.

AIMS: To study the role of curcumin on glioma cells via the SHH/GLI1 pathway in vitro and vivo. METHODS: The effects of curcumin on proliferation, migration, apoptosis, SHH/GLI1 signaling, and GLI1 target genes expression were evaluated in multiple glioma cell lines in vitro. A U87-implanted nude mice model was used to study the role of curcumin on tumor volume and the suppression efficacy of GLI1. RESULTS: Curcumin showed cytotoxic effects on glioma cell lines in vitro. Both mRNA and protein levels of SHH/GLI1 signaling (Shh, Smo, GLI1) were downregulated in a dose- and time-dependent manner. Several GLI1-dependent target genes (CyclinD1, Bcl-2, Foxm1) were also downregulated. Curcumin treatment prevented GLI1 translocating into the cell nucleus and reduced the concentration of its reporter. Curcumin suppressed cell proliferation, colony formation, migration, and induced apoptosis which was mediated partly through the mitochondrial pathway after an increase in the ratio of Bax to Bcl2. Intraperitoneal injection of curcumin in vivo reduced tumor volume, GLI1 expression, the number of positively stained cells, and prolonged the survival period compared with the control group. CONCLUSION: This study shows that curcumin holds a great promise for SHH/GLI1 targeted therapy against gliomas.

Regulation of ASIC1 by Ca2+/calmodulin-dependent protein kinase II in human glioblastoma multiforme.

Recent studies have implicated the acid-sensing ion channel 1 (ASIC1), a proton-gated cation channel that belongs to the epithelial sodium channel (ENaC)/Degenerin family, plays an important role in glioma cell migration. Among the ASIC subunits, only ASIC1a has been found be calcium permeable. However, it has not been determined whether Ca2+/calmodulin-dependent protein kinase II (CaMKII) regulates ASIC1 in glioblastoma multiforme (GBM). Herein, we report that ASIC1 and CaMKII assemble to form a functional complex at the plasma membrane of GBM cells. We found that migration ability was significantly attenuated in GBM cells that were pre-treated with autocamtide-2-related inhibitory peptide (AIP), a CaMKII-specific inhibitor, or psalmotoxin 1 (PcTX-1), a selective ASIC1 blocker. Furthermore, the inhibitory effect of AIP or PcTX-1 on migration was diminished when ASIC1 was knocked down in GBM cells; when ASIC1 knockdown GBM cells were concurrently treated with these two inhibitors, cell migration was slightly but significantly decreased. Using whole-cell patch-clamp recordings, we detected an amiloride-sensitive current in GBM cells, and this current was significantly inhibited by both PcTX-1 and AIP. Moreover, the magnitude of this current was dramatically decreased when ASIC1 was knocked down in GBM cells. The addition of AIP failed to further decrease the amplitude of this current. Taken together, these data suggest that ASIC1 and CaMKII form a functional complex in GBM cells. Furthermore, it can be concluded that CaMKII regulates the activity of ASIC1, which is associated with the ability of GBM cells to migrate.

MiR-139 inhibits Mcl-1 expression and potentiates TMZ-induced apoptosis in glioma.

AIMS: Mcl-1, an antiapoptotic member of the Bcl-2 family, is overexpressed in human glioblastoma, conferring a survival advantage to tumor cells. The mechanisms underlying its dysregulation have not been clarified. In this study, we explored the involvement of micro-RNAs that acted as endogenous sequence-specific suppressors of gene expression. METHODS AND RESULTS: Using computational and TCGA analysis, we identified miR-139 as being downregulated in glioblastoma in comparison with human brain tissue, as well as possessing a putative target site in Mcl-1 mRNA. Overexpression of miR-139 led to a clear decrease in Mcl-1 expression in gliomas. Reporter assays revealed direct post-transcriptional regulation involving miR-139 and the 3'-untranslated region of Mcl-1. Human glioma tissues with low expression of miR-139 displayed higher expression of Mcl-1 protein than those with high expression, suggesting that low miR-139 contributes to Mcl-1 overexpression. In addition, upregulation of miR-139 suppressed the proliferation and enhanced temozolomide (TMZ)-induced apoptosis. Finally, we observed that Mcl-1 knockdown resulted in similar effects compared with miR-139 transfection. CONCLUSION: Our results suggested that miR-139 negatively regulated Mcl-1 and induced apoptosis in cooperation with an anticancer drug TMZ in glioma.

Liposomes modified with P-aminophenyl-α-D-mannopyranoside: a carrier for targeting cerebral functional regions in mice.

Targeting of intracerebral functional regions has been limited by the inability to transport drugs across the blood-brain barrier (BBB) and by poor accumulation in these regions. To overcome these hurdles, liposomes modified with P-aminophenyl-α-d-mannopyranoside (MAN) were used as a fluorescent dye carrier through the BBB and used the specific distribution of liposomes (LIP) modified with MAN (MAN-LIP) to target various functional regions of the brain. An in vitro BBB model was established to evaluate the transendothelial ability of MAN-LIP, and liposomes uptake by C6 glioma cells was analyzed by flow cytometry and live cell imaging. Liposome targeting was evaluated using in vivo and ex vivo imaging. After MAN-LIP administration, the transendothelial ability and the delivery of fluorescent dye to the brain significantly increased. MAN-LIP concentrated in the cortex at 4 h, shifting distribution to the cerebellum and brainstem at 12 h. The fluorescence intensity in the hippocampus and pontine nuclei remained high and stable over a period of 12 h. The results demonstrate that MAN-LIP is able to enhance cellular uptake in vitro and also promotes penetration through the BBB and accumulation in the brain with a distinct spatio-temporal pattern.

HP-ß-CD-PLGA nanoparticles improve the penetration and bioavailability of puerarin and enhance the therapeutic effects on brain ischemia-reperfusion injury in rats.

It is well known that puerarin attenuates ischemia-reperfusion injury and promotes function recovery of ischemic region. However, due to its reverse physiochemical properties, puerarin does not easily cross the blood-brain barrier. The aim of the present study is to create puerarin nanoparticles which increase and prolong the puerarin concentration in the brain. Using emulsion solvent evaporation techniques, we designed puerarin-loaded poly(D,L-lactic-co-glycolic acid) nanoparticles. Hydroxypropyl beta cyclodextrin (HP-ß-CD) was used to increase the solubility of puerarin and gelatin to enhance viscosity of inner water phase, which improved puerarin entrapment. The drug release kinetics and nanoparticle degradation in phosphate buffered saline (PBS) were analyzed by electronic microscopy and high-performance liquid chromatography. Computerized tomography scans were used to detect the infarction volume and electroencephalogram (EEG) was recorded to estimate the recovery of brain function. The results showed that the combined HP-ß-CD and gelatin significantly improved the entrapment efficiency. The infarction volume was significantly decreased on days 3 and 7 after the administration of puerarin nanoparticles compared with that of control and pure puerarin. EEG was also significantly improved. Puerarin nanoparticles are potentially applicable for the brain injury induced by ischemic-reperfusion.

Pifithrin-α enhances the survival of transplanted neural stem cells in stroke rats by inhibiting p53 nuclear translocation.

AIMS: To examine a novel strategy to enhance the survival of grafted neural stem cells (NSCs) in stroke model. METHODS: Using a cell counting kit-8 (CCK-8) and TUNEL assay to test the protective effects of p53 inhibitor, pifithrin-α (PFT-α), on oxygen glucose deprivation (OGD) in NSCs. We compared the effects of vehicle + NSCs and FFT-α + NSCs on the efficacy of transplantation in stroke rat model using behavioral analysis, immunohistochemistry, etc. RESULTS: Pifithrin-α increased viability and decreased apoptosis in NSCs after OGD in vitro. By in vivo studies, we showed that the best recovery of neurological function in the stroke rats and the maximum survival of grafted NSCs were found in the PFT-α + NSCs group. Twelve hours after cell transplantation, p53 was localized to the nuclei of grafted NSCs in the vehicle + NSCs group but was primarily localized to the cytoplasm in the PFT-α + NSCs group. The p53-upregulated modulator of apoptosis (PUMA) was highly expressed among the grafted cells in the vehicle + NSCs group compared with that in the PFT-α + NSCs group. CONCLUSION: Our results indicate that PFT-α enhances the survival of grafted NSCs through the inhibition of p53 translocation into the nucleus.

Gamma Knife irradiation-induced histopathological changes in the trigeminal nerves of rhesus monkeys.

OBJECT: The authors' goal was to observe histopathological changes in the trigeminal nerve after Gamma Knife surgery (GKS) in rhesus monkeys, and to investigate the radiobiological mechanism of GKS for primary trigeminal neuralgia. The nerve length-dosage effect of irradiation is also discussed. METHODS: One of 5 rhesus monkeys randomly served as a control, and the other 4 monkeys were randomly administered a target radiation dose of 60, 70, 80, or 100 Gy (a different dose in each animal). The size of the collimator was 4 mm, and the target point was the trigeminal nerve root. In each experimental monkey, one side was exposed to single-target-point irradiation, and the contralateral side was exposed to double-target-point irradiation. After 6 months, the trigeminal nerve root was examined using light microscopy, transmission electron microscopy, and immunohistochemistry. RESULTS: At each radiation dose, the damage to the nerve tissue by single-target-point irradiation was identical to that caused by double-target-point irradiation. In the trigeminal nerve tissues of the monkeys irradiated with 60 and 70 Gy, there was limited nerve demyelination and degeneration, fragmentation, or loss of axons. In the trigeminal nerve tissue of the monkey irradiated with 80 Gy, the nerve tissue showed a disordered structure. In the trigeminal nerve tissue of the monkey irradiated with 100 Gy, there was severe derangement in the structure of the nerve tissue, and extensive demyelination, fragmentation, and loss of axons. CONCLUSIONS: The target doses of 60 and 70 Gy have very little impact on the structure of the trigeminal nerve. Irradiation at 80 Gy can cause partial degeneration and loss of axons and demyelination. A 100-Gy dose can cause some necrosis of neurons. Comparing the single-target-point with the double-target-point irradiation, the extent of damage to the nerve tissue is identical, and no difference in the nerve length-dosage effect was found.