Peroxiredoxin-3 plays a neuroprotective role in early brain injury after experimental subarachnoid hemorrhage in rats.

Subarachnoid hemorrhage (SAH), a type of hemorrhagic stroke, is a neurological emergency associated with a high morbidity and mortality rate. After SAH, early brain injury (EBI) is the leading cause of poor prognosis in SAH patients. Peroxiredoxins (PRDXs) are a family of sulphhydryl-dependent peroxidases. Peroxiredoxin-3 (PRDX3) is mainly located in the mitochondria of neurons, which can remove hydrogen peroxide (H2O2); however, the effect of PRDX3 on EBI after SAH remains unclear. In this study, an endovascular perforation model was used to mimic SAH in Sprague Dawley rats in vivo. The results revealed that after SAH, PRDX3 levels decreased in the neurons. PRDX3 overexpression by neuron-specific adeno-associated viruses upregulated PRDX3 levels. Furthermore, PRDX3 overexpression improved long- and short-term behavioral outcomes and alleviated neuronal impairment in rats. Nissl staining revealed that the upregulation of PRDX3 promoted cortical neuron survival. PRDX3 overexpression decreased the H2O2 content and downregulated caspase-9 expression. In conclusion, PRDX3 participates in neuronal protection by inhibiting the neuronal mitochondria-mediated death pathway; PRDX3 may be an important target for EBI intervention after SAH.

Effects of PAK1/LIMK1/Cofilin-mediated Actin Homeostasis on Axonal Injury after Experimental Intracerebral Hemorrhage.

Intracerebral hemorrhage (ICH) is a hemorrhagic stroke with a high mortality and disability rate. Neurological impairment after ICH is closely associated with neuronal axon damage. Serine/threonine-protein kinase p21 activated kinase 1 (PAK1) participates in cytoskeletal remodeling and regulates the F-actin and G-actin ratio in neuronal axons, but the function of PAK1 after ICH remains unclear. We established an in vivo rat ICH model by autologous whole blood injection into the right basal ganglia and an in vitro neuron oxyhemoglobin intervention. The results showed that the phosphorylated PAK1 level increased while the PAK1 expression level unchanged after ICH, After PAK1 knockdown, PAK1 and phosphorylated PAK1 levels were both reduced. Meanwhile, downstream proteins LIMK1 and cofilin expression levels were unchanged while phosphorylated LIMK1 and phosphorylated cofilin were decreased. F-actin/G-actin ratio decreased after PAK1 knockdown. Moreover, PAK1 knockdown improved short- and long-term neurobehavioral impairments in rats. In vitro, phosphorylated PAK1 expression increased after oxyhemoglobin intervention. After PAK1 knockdown, the axon length of neurons increased while F-actin/G-actin ratio decreased. Spersman correlation analysis showed a negative correlation between phospho-PAK1 fluorescence intensity and neuronal axon length. Knockdown of PAK1 increased the live/dead cell ratio and promoted neurons survival. Our study showed that PAK1 is involved in ICH early secondary brain injury by affecting F-actin/G-actin ratio through the PAK1/LIMK1/cofilin pathway. PAK1 may be an essential target for early secondary brain injury intervention after ICH.

Loss of monocarboxylate transporter 1 aggravates white matter injury after experimental subarachnoid hemorrhage in rats.

Monocarboxylic acid transporter 1 (MCT1) maintains axonal function by transferring lactic acid from oligodendrocytes to axons. Subarachnoid hemorrhage (SAH) induces white matter injury, but the involvement of MCT1 is unclear. In this study, the SAH model of adult male Sprague-Dawley rats was used to explore the role of MCT1 in white matter injury after SAH. At 48 h after SAH, oligodendrocyte MCT1 was significantly reduced, and the exogenous overexpression of MCT1 significantly improved white matter integrity and long-term cognitive function. Motor training after SAH significantly increased the number of ITPR2+SOX10+ oligodendrocytes and upregulated the level of MCT1, which was positively correlated with the behavioral ability of rats. In addition, miR-29b and miR-124 levels were significantly increased in SAH rats compared with non-SAH rats. Further intervention experiments showed that miR-29b and miR-124 could negatively regulate the level of MCT1. This study confirmed that the loss of MCT1 may be one of the mechanisms of white matter damage after SAH and may be caused by the negative regulation of miR-29b and miR-124. MCT1 may be involved in the neurological improvement of rehabilitation training after SAH.

TMEM175 mediates Lysosomal function and participates in neuronal injury induced by cerebral ischemia-reperfusion.

As the main organelles for the clearance of damaged proteins and damaged organelles, the function of lysosomes is crucial for maintaining the intracellular homeostasis of long-lived neurons. A stable acidic environment is essential for lysosomes to perform their functions. TMEM175 has been identified as a new K+ channel that is responsible for regulating lysosomal membrane potential and pH stability in neurons. This study aimed to understand the role of TMEM175 in lysosomal function of neurons and neuronal injury following cerebral ischemia-reperfusion (I/R). A middle-cerebral-artery occlusion/reperfusion (MCAO/R) model was established in adult male Sprague-Dawley rats in vivo, and cultured neurons were exposed to oxygen-glucose deprivation/reoxygenation (OGD/R) to mimic ischemia-reperfusion (I/R) injury in vitro. We found that the protein level of TMEM175 decreased after cerebral I/R injury and that TMEM175 overexpression ameliorated MCAO/R-induced brain-cell death and neurobehavioral deficits in vivo. Furthermore, these results were recapitulated in cultured neurons. Acridine orange (AO) staining, as well as LysoSensor Green DND-189, cathepsin-B (CTSB), and cathepsin-D (CTSD) activities, showed that TMEM175 deficiency inhibited the hydrolytic function of lysosomes by affecting lysosomal pH. In contrast, TMEM175 upregulation reversed OGD/R-induced lysosomal dysfunction and impaired mitochondrial accumulation in cultured neurons. TMEM175 deficiency induced by cerebral I/R injury leads to compromised lysosomal pH stability, thus inhibiting the hydrolytic function of lysosomes. Consequently, lysosomal-dependent degradation of damaged mitochondria is suppressed and thereby exacerbates brain damage. Exogenous up-regulation of TMEM175 protein level could reverse the neuronal lysosomal dysfunction after ischemia-reperfusion.

Next generation sequencing and molecular imaging identify EGFR mutation and amplification in a glioblastoma multiforme patient treated with an EGFR inhibitor: a case report.

Epidermal growth factor receptor (EGFR) mutations and amplifications are frequently reported in glioblastoma multiforme (GBM) patients. In this case report, we utilize next-generation sequencing (NGS) and EGFR molecular imaging to investigate intratumoral heterogeneity in a male patient presenting with GBM. Further, we describe the patient's clinical course as well as outcomes of targeted EGFR therapy with erlotinib, an EGFR tyrosine kinase inhibitor (TKI). NGS demonstrated the presence of an EGFR mutation and amplification in our patient. Molecular imaging revealed a heterogeneous expression pattern of EGFR in the frontal and temporal lobes. This patient briefly responded to erlotinib therapy. However, the patient relapsed and died from progressive neurological deterioration. Partial response and acquired secondary resistance may be attributed to intratumoral heterogeneity. Combination of NGS and EGFR molecular imaging may be helpful in understanding intratumoral molecular heterogeneity and may aid in developing individualized GBM treatments, thereby improving outcomes.

MicroRNA-140-5p inhibits cell proliferation and invasion by regulating VEGFA/MMP2 signaling in glioma.

Glioma is the most common primary malignant tumor of the central nervous system, which results in both a poor prognosis and outcome because of the aggressive progression of disease, growth and resistance to surgery, chemotherapy, and radiotherapy. MiR-140-5p is a small, non-coding single-stranded RNA molecule, which was previously studied in the settings of human tongue cancer, hepatocellular carcinoma, and colorectal cancer. However, detailed data that formally demonstrate the contribution of miR-140-5p to glioma development are missing. Similarly, relatively little is known about the relationship of miR-140-5p, vascular endothelial growth factor A, and matrix metalloproteinase-2 in glioma progression. In this study, we found that miR-140-5p expression was significantly decreased in glioma tissues and in the glioma cell-lines U87 and U251 as compared with non-cancerous brain tissues by quantitative real-time polymerase chain reaction. In addition, miR-140-5p inhibited glioma cell proliferation and invasion and promoted glioma cell apoptosis both in vivo and in vitro. Interestingly, while the expression levels of miR-140-5p were higher in glioma cells, the messenger RNA or protein expression levels of vascular endothelial growth factor A and matrix metalloproteinase-2 were lower in glioma cells as determined by quantitative real-time polymerase chain reaction, western blot assay, and immunohistochemistry. By contrast, downregulation in the expression levels of miR-140-5p augmented the messenger RNA and protein expression levels of both vascular endothelial growth factor A and matrix metalloproteinase-2. These findings suggested that miR-140-5p inhibited glioma proliferation and invasion by regulating the vascular endothelial growth factor A/matrix metalloproteinase-2 signaling pathway both in vitro and in vivo.

Human fibulin-3 protein variant expresses anti-cancer effects in the malignant glioma extracellular compartment in intracranial xenograft models.

BACKGROUND: Decades of cytotoxic and more recently immunotherapy treatments for malignant glioma have had limited success due to dynamic intra-tumoral heterogeneity. The dynamic interplay of cancer cell subpopulations has been found to be under the control of proteins in the cancer microenvironment. EGF-containing fibulin-like extracellular matrix protein (EFEMP1) (also fibulin-3) has the multiple functions of suppressing cancer growth and angiogenesis, while promoting cancer cell invasion. EFEMP1-derived tumor suppressor protein (ETSP) retains EFEMP1's anti-growth and anti-angiogenic functions while actually inhibiting cancer cell invasion. METHODS: In this study, we examined the therapeutic effect on glioblastoma multiforme (GBM) of an in vitro synthesized protein, ZR30, which is based on the sequence of ETSP, excluding the signaling peptide. RESULTS: ZR30 showed the same effects as ETSP in blocking EGFR/NOTCH/AKT signaling pathways, when applied to cultures of multiple GBM cell lines and primary cultures. ZR30's inhibition of MMP2 activation was shown not only for GBM cells, but also for other types of cancer cells having overexpression of MMP2. A significant improvement in survival of mice with orthotopic human GBM xenografts was observed after a single, intra-tumoral injection of ZR30. Using a model mimicking the intra-tumoral heterogeneity of GBM with cell subpopulations carrying different invasive and proliferative phenotypes, we demonstrated an equal and simultaneous tumor suppressive effect of ZR30 on both tumor cell subpopulations, with suppression of FOXM1 and activation of SEMA3B expressions in the xenografts. CONCLUSION: Overall, the data support a complementary pleiotrophic therapeutic effect of ZR30 acting in the extracellular compartment of GBM.

miR-132 can inhibit glioma cells invasion and migration by target MMP16 in vitro.

Gliomas are the most common malignant primary brain tumors, and new clinical biomarkers and therapeutic targets are imminently required. MicroRNAs (miRNAs) are a novel class of small non-coding RNAs (∼22nt) involved in the regulation of various biological processes. Here, by using real-time polymerase chain reaction, miRNA-132 was found to be significantly deregulated in glioma tissues. Based on the prediction of the target genes of miR-132, we hypothesized that there is a significant association between miR-132 and matrix metalloproteinase (MMP) 16 (MT3-MMP), a protein of the MMP family. We showed that the up-expression of miR-132 inhibited cell migration and invasion in the human glioma cell lines A172, SHG44, and U87. Furthermore, the overexpression of miR-132 reduced the expression of MMP16 in A172, SHG44, and U87 cells. Taken together, our study suggested that miR-132 affects glioma cell migration and invasion by MMP16 and implicates miR-132 as a metastasis-inhibiting miRNA in gliomas.

Isolation and characteristics of CD133­/A2B5+ and CD133­/A2B5­ cells from the SHG139s cell line.

In glioma tissues, there are small cell populations with the capability of sustaining tumor formation. These cells are referred to as glioma stem cells (GSCs). However, the presence of subpopulations of GSCs, and the differences between each subpopulation remain to be fully elucidated. In the present study, CD133­/A2B5­ and CD133­/A2B5+ cells from the SHG139 GSC cell line (SHG139s) were isolated using magnetic­activated cell sorting. Following xenografting into nude mice, the two isolated subpopulations generated tumors. The characteristics of the two subpopulations were investigated extensively, and it was found that the two exhibited cancer stem cell characteristics. These cells expressed stem cell markers, exhibited a neurosphere­like appearance, and were found to exhibit self­renewal and multipotency capabilities. Subsequently, the self­renewal and proliferation abilities of the two subpopulations were compared. It was found that the A2B5­ cells had a higher proliferative index and a higher self­renewal ability, compared with the A2B5+ cells. In addition, the A2B5­ cells exhibited increased angiogenic ability. However, the invasion ability of the A2B5+ cells was higher than that of the A2B5­ cells. Taken together, the results of the present study suggested that there are different cell subpopulations in GSCs, and each subpopulation has its own properties.

[Establishment of a new human glioma cell line and analysis of its biological characteristics].

OBJECTIVE: To establish a new glioma cell line and analyze its biological characteristics, and to provide a useful cellular tool with new features for cancer research. METHODS: Glioma tissue was taken from surgical specimen clinical of a clinical patient. Primary culture was carried out, and a cell line (SHG139) was established after 10 passages. Immunofluorescence staining was performed to detect the expression of proteins, and cell proliferation and cycle were detected by flow cytometry method (FCM). The biological characteristics of SHG139 cells were detected by chromosome karyotype analysis. SHG139s glioma cells derived from SHG139 glioma cell line were cultured with neural stem cell medium. Then stem cell markers were determined. SHG139s cells were induced with serum-containing medium, and their expression of A2B5, GFAP, ß-III tubulin, and GalC was detected. Intracranial xenograft tumor of both SHG139 glioma cells and SHG139s glioma stem cell spheres was generated in rats. RESULTS: The expressions of A2B5, GalC, GFAP, S-100, and vimentin in the 20 and 60 passages of SHG139 cells were positive, consistent with the immunohistochemical results and pathological features. SHG139 cells proliferated significantly within 24 h after subculture, and their total number of chromosomes was 68 and mostly multiploid. They were positive for A2B5 (84.12±9.96)%, nestin (73.86±5.01)%, and NG2 (73.37±2.09)%. SHG139s cells were induced, and the ratio of positive cells of GFAP, ß-III tubulin and GalC was (92.89±2.24)%, (64.85±4.09)% and (33.57±4.14)%, respectively. CONCLUSIONS: SHG139 is an astroglioma cell line, from which SHG139s cells can be successfully obtained by culture with NSCM. SHG139s cells are of A2B5(+)/CD133(-) GSCs subgroup cells, with potentials of self-renewal and multi-directional differentiation. Compared with the intracranial SHG139 xenograft tumor, the intracranial SHG139s xenograft tumor is more malignant and aggressive.

MicroRNA-184 inhibits cell proliferation and invasion, and specifically targets TNFAIP2 in Glioma.

BACKGROUND: miRNA-184 is an oncogene in human hepatocellular carcinoma but acts as a tumor suppressor in tongue squamous cell carcinoma. Studies have shown that miR-184 was down-regulated in glioma and TNFα-induced protein 2 (TNFAIP2) was closely related to tumorigenesis. This study aimed to determine the functions of miR-184 in glioma and the mechanisms of miRNA-184-TNFAIP2 mediated glioma progression. METHODS: Real-time reverse-transcription PCR detected expression of miR-184 and TNFAIP2. U87 and U251 cells were transfected with miR-184 mimic, inhibitor, or negative control miRNA, and their invasion abilities were assayed. Cellular proliferation was measured by the cell counting kit-8 assay. miR-184 effects on glioma cell apoptosis and cell cycle were assessed by flow cytometer. Biological information software have predicted that miR-184 could target TNFα-induced protein 2 (TNFAIP2), Which was further validated by Western blot and qRT-PCR in glioma cells. In vivo, U87 cells transduced with either lentiviral over-expressed miR-184 or control lentivirus were injected into nude mice subcutaneously and intracranial respectively. RESULTS: Expression of miR-184 was significantly lower in glioma tissues and cell-lines compared to normal brain tissues. Protein and mRNA expression of TNFAIP2 were inversely correlated with miR-184 in glioma. In vitro, proliferation and invasion abilities were also decreased in U87 and U251 cells after transfection with miR-184 mimic. In vivo, the xenografted tumor size in the miR-184 overexpressing group were smaller than the miR-NC group. Concordantly, U87 and U251 cells transfected with miR-184 mimic had a higher apoptosis rate, triggering an accumulation of cells at the G0/G1 phase and decreased cells in S-phase. CONCLUSIONS: miR-184 could regulate TNFAIP2 expression and affected its translation in glioma. miR-184 could also inhibit glioma progression and might serve as a novel therapeutic target in glioma.

miR-494-3p Regulates Cellular Proliferation, Invasion, Migration, and Apoptosis by PTEN/AKT Signaling in Human Glioblastoma Cells.

Malignant gliomas are the most common primary brain tumors, and the molecular mechanisms involving their progression and recurrence are still largely unclear. Substantial data indicate that the oncogene miR-494-3p is significantly elevated in gliomas, but the molecular functions of miR-494-3p in gliomagenesis are largely unknown. The present study aimed to explore the role of miR-494-3p and its molecular mechanism in human brain gliomas, malignant glioma cell lines, and cancer stem-like cells. The expression level of miR-494-3p in 48 human glioma issues and 8 normal brain tissues was determined using stem-loop real-time polymerase chain reaction (PCR). To study the function of miR-494-3p inhibitor in glioma cells, the miR-494-3p inhibitor lentivirus was used to transfect glioma cells. Transwell invasion system was used to estimate the effects of miR-494-3p inhibitor on the invasiveness of glioma cells. A mouse model was used to test the effect of miR-494-3p inhibitor on glioma proliferation and invasion in vivo. Results showed that the expression of miR-494-3p in human brain glioma tissues was higher than in normal brain tissues. Downregulated expression of miR-494-3p can inhibit the invasion and proliferation and promote apoptosis in glioma cells. Quantitative reverse transcription PCR and Western blotting analysis revealed that the expression of PTEN was increased after downexpression of miR-494-3p in glioma cells (U87 and U251). miR-494-3p inhibitor could prevent migration, invasion, proliferation, and promote apotosis in gliomas through PTEN/AKT pathway. Therefore, the study results have shown that miR-494-3p may act as a therapeutic target in gliomas.

Aggressive invasion is observed in CD133-/A2B5+ glioma-initiating cells.

Glioblastoma multiforme is the most common and fatal primary brain tumor in adults. Aggressive invasion of glioblastoma cells into brain tissue often limits complete surgical resection and contributes to therapeutic resistance. The cell surface marker, CD133, has been identified as a putative stem cell marker in normal and malignant brain tissues; CD133-/A2B5+ cells exhibit neural stem-like cell properties. The invasive properties and the molecular mechanisms of CD133-/A2B5+ glioma-initiating cells (GICs) were investigated in the process of self-renewal and tumorigenesis. An increased number of invasive cells through matrigel and an increase in migratory cells through filters were observed in CD133-/A2B5+ GIC populations compared with matched non-initiating tumor cell populations. Considerable changes were detected in expression of mRNA and protein associated with migration or invasion. CD133-/A2B5+ GIC demonstrated infiltrating growth patterns and displayed greater invasive potential under fluorescent microscopy comparing with the matched non-initiating tumor cells after cells labeled with red fluorescence protein were transplanted into the brains of athymic/nude mice. CD133-/A2B5+ GICs possess strong migratory and invasive capacity. These infiltrating cells in the invasive fronts may be responsible for rapid tumor recurrence following conventional treatments. CD133-/A2B5+ GICs may be an important subpopulation with high invasive potential and they should not be ignored when targeting GICs to prevent GBM recurrence.

Identification of a NFKBIA polymorphism associated with lower NFKBIA protein levels and poor survival outcomes in patients with glioblastoma multiforme.

The aberrant constitutive activation of nuclear factor-κB (NF-κB) has been observed in glioblastomas, while NF-κB inhibitor alpha (NFKBIA) inhibits the NF-κB signaling pathway under several physiological processes. However, the contribution of NFKBIA to glioblastomas is poorly understood. In the present study, using gene sequencing, we identified rs1957106 as a novel single nucleotide polymorphism (SNP) in NFKBIA in glioblastoma and found that it was more frequently present in glioblastoma patients. In addition, we examined the association between different genotypes of the rs1957106 SNP of NFKBIA and the gene copy number, mRNA level and protein expression of NFKBIA. The SNP rs1957106 CT and TT genotypes were found to be associated with lower NFKBIA protein levels and a poor prognosis of pateints with glioblastoma. Hence, by identifying rs1957106 as a novel SNP in NFKBIA in glioblastoma patients, we provide a new platform for further investigating the function of NFKBIA in the pathobiology of glioblastoma.

Comparative analysis of pathology and boronophenylalanine uptake in experimental orthotopic and heterotopic amelanotic melanoma.

Pathobiologic characteristics of cerebral and cutaneous melanoma may cause an increase in mortality resulting from brain metastases in advanced melanoma patients, in addition to anatomic lesions and biological effects caused by the tumor location. We established intracranial and subcutaneous melanoma models using cultured malignant cells derived from amelanotic melanoma. The median survival times in a mouse model with intracranial tumors was 20 days, but a mouse model with subcutaneous tumors did not show cachexia until they were killed 28 days after inoculation with tumor cells. Histopathological analysis showed that a high karyokinesis phase and nuclear pleomorphism appeared in the intracranial model compared with the subcutaneous tumor model mice. The tumor boron concentration at 2.5 h after boronophenylalanine administration was 15.21±3.88 µg/g in an intracranial melanoma xenograft and 19.85±3.63 µg/g in a subcutaneous melanoma xenograft. Intracranial melanoma showed more malignancy and shorter survival time than did subcutaneous melanoma when the same number of tumor cells were injected, and subcutaneous and intracranial amelanotic malignant melanoma tumors are both fitted for boron neutron capture therapy.

MicroRNA-16 inhibits glioma cell growth and invasion through suppression of BCL2 and the nuclear factor-κB1/MMP9 signaling pathway.

Recent studies have identified a class of small non-coding RNA molecules, named microRNA (miRNA), that is dysregulated in malignant brain glioblastoma. Substantial data have indicated that miRNA-16 (miR-16) plays a significant role in tumors of various origins. This miRNA has been linked to various aspects of carcinogenesis, including cell apoptosis and migration. However, the molecular functions of miR-16 in gliomagenesis are largely unknown. We have shown that the expression of miR-16 in human brain glioma tissues was lower than in non-cancerous brain tissues, and that the expression of miR-16 decreased with increasing degrees of malignancy. Our data suggest that the expression of miR-16 and nuclear factor (NF)-κB1 was negatively correlated with glioma levels. MicroRNA-16 decreased glioma malignancy by downregulating NF-κB1 and MMP9, and led to suppressed invasiveness of human glioma cell lines SHG44, U87, and U373. Our results also indicated that upregulation of miR-16 promoted apoptosis by suppressing BCL2 expression. Finally, the upregulation of miR-16 in a nude mice model of human glioma resulted in significant suppression of glioma growth and invasiveness. Taken together, our experiments have validated the important role of miR-16 as a tumor suppressor gene in glioma growth and invasiveness, and revealed a novel mechanism of miR-16-mediated regulation in glioma growth and invasiveness through inhibition of BCL2 and the NF-κB1/MMP-9 signaling pathway. Therefore, our experiments suggest the possible future use of miR-16 as a therapeutic target in gliomas.

Boron neutron capture therapy induces cell cycle arrest and cell apoptosis of glioma stem/progenitor cells in vitro.

BACKGROUND: Glioma stem cells in the quiescent state are resistant to clinical radiation therapy. An almost inevitable glioma recurrence is due to the persistence of these cells. The high linear energy transfer associated with boron neutron capture therapy (BNCT) could kill quiescent and proliferative cells. METHODS: The present study aimed to evaluate the effects of BNCT on glioma stem/progenitor cells in vitro. The damage induced by BNCT was assessed using cell cycle progression, apoptotic cell ratio and apoptosis-associated proteins expression. RESULTS: The surviving fraction and cell viability of glioma stem/progenitor cells were decreased compared with differentiated glioma cells using the same boronophenylalanine pretreatment and the same dose of neutron flux. BNCT induced cell cycle arrest in the G2/M phase and cell apoptosis via the mitochondrial pathway, with changes in the expression of associated proteins. CONCLUSIONS: Glioma stem/progenitor cells, which are resistant to current clinical radiotherapy, could be effectively killed by BNCT in vitro via cell cycle arrest and apoptosis using a prolonged neutron irradiation, although radiosensitivity of glioma stem/progenitor cells was decreased compared with differentiated glioma cells when using the same dose of thermal neutron exposure and boronophenylalanine pretreatment. Thus, BNCT could offer an appreciable therapeutic advantage to prevent tumor recurrence, and may become a promising treatment in recurrent glioma.

[Phenotype of SHG-44 glioma stem cell spheres and pathological characteristics of their xenograft tumors].

OBJECTIVE: To study the phenotype and tumorigenicity of SHG-44 glioma stem cell spheres and the pathological characteristics of their xenograft tumors. METHODS: SHG-44 glioma cells were cultured under neural stem cell medium and glioma stem cell spheres were collected. Immunocytochemistry was used to dectet the expression of CD133, nestin, A2B5, vimentin, VEGFR-2 and IDH R132H. Cell spheres were induced using serum-containing medium, and the expression of CD133, nestin, vimentin, GFAP, ß-III tubulin and GalC in the cell spheres were detected. The expression of CD133, nestin, VEGFR-2, GFAP, S-100 and CD34 in the intracranial xenograft tumor tissues was detected using immunohistochemistry. The pathological characteristics of orthotopic xenograft tumors generated from the SHG-44 glioma cells and SHG-44 glioma stem cell spheres were compared. RESULTS: SHG-44 glioma stem cell spheres were collected successfully after cultured under neural stem cell medium. The ratio of CD133(+) cells in the passage 10 SHG-44 glioma stem cell spheres was (71.63 ± 5.92)%, significantly higher than that in the SHG-44 glioma cells [(1.95 ± 1.45)%]. Immunocytochemistry showed that in the SHG-44 glioma cell spheres, the ratio of nestin(+) cells was (84.06 ± 7.58)%, vimentin(+) cells (29.11 ± 3.44)%, VEGFR 2(+) cells (64.44 ± 3.69)%, and A2B5(+) cells (14.08 ± 2.19)%. A subpopulation of cells with mutation of IDH R132H was detected harboring in the SHG-44 glioma cell spheres. After induction of differentiation with serum-containing medium, the ratio of CD133(+) cells was (1.89 ± 1.27)%, nestin(+) cells (6.67 ± 2.75)%, vimentin(+) cells (93.75 ± 2.95)%, GFAP (+) cells (91.33 ± 4.75)%, ß-III tubulin(+) cells (82.36 ± 4.02)%, and GalC(+) cells (8.92 ± 3.19)%. Immunohistochemistry showed positive expression of GFAP, S-100, VEGFR-2, and negative of CD133 and nestin in the orthotopic xenograft tumors. A very small amount of human-specific CD34 cells formed a tubular structure. Compared with the SHG-44 glioma cell-formed xenograft tumor, the SHG-44 glioma stem cell-formed xenograft tumor exhibited a higher local invasiveness. CONCLUSIONS: SHG-44 glioma cell spheres are successfully collected after cultured under neural stem cell medium. They belong to the CD133(+)A2B5(-) GSC subpopulation, highly expressing VEGFR-2, possess the ability of both self-renewal and multi-directional differentiation, and may participate in the formation of vasculogenic mimicry.

UHRF2 mRNA expression is low in malignant glioma but silencing inhibits the growth of U251 glioma cells in vitro.

UHRF2 is a member of the ubiquitin plant homeo domain RING finger family, which has been proven to be frequently up-regulated in colorectal cancer cells and play a role as an oncogene in breast cancer cells. However, the role of UHRF2 in glioma cells remains unclear. In this study, we performed real-time quantitative PCR on 32 pathologically confirmed glioma samples (grade I, 4 cases; grade II, 11 cases; grade III, 10 cases; and grade IV, 7 cases; according to the 2007 WHO classification system) and four glioma cell lines (A172, U251, U373, and U87). The expression of UHRF2 mRNA was significantly lower in the grade III and grade IV groups compared with the noncancerous brain tissue group, whereas its expression was high in A172, U251, and U373 glioma cell lines. An in vitro assay was performed to investigate the functions of UHRF2. Using a lentivirus-based RNA interference (RNAi) approach, we down-regulated UHRF2 expression in the U251 glioma cell line. This down- regulation led to the inhibition of cell proliferation, an increase in cell apoptosis, and a change of cell cycle distribution, in which S stage cells decreased and G2/M stage cells increased. Our results suggest that UHRF2 may be closely related to tumorigenesis and the development of gliomas.

Selective uptake of boronophenylalanine by glioma stem/progenitor cells.

The success of boron neutron capture therapy (BNCT) depends on the amount of boron in cells and the tumor/blood and tumor/(normal tissue) boron concentration ratios. For the first time, measurements of boron uptake in both stem/progenitor and differentiated glioma cells were performed along with measurements of boron biodistribution in suitable animal models. In glioma stem/progenitor cells, the selective accumulation of boronophenylalanine (BPA) was lower, and retention of boron after BPA removal was longer than in differentiated glioma cells in vitro. However, boron biodistribution was not statistically significantly different in mice with xenografts.