c­Jun N­terminal kinase inhibition attenuates early brain injury induced neuronal apoptosis via decreasing p53 phosphorylation and mitochondrial apoptotic pathway activation in subarachnoid hemorrhage rats.

Early brain injury (EBI)­induced neuronal apoptosis is primarily responsible for the subsequent complications of aneurysmal subarachnoid hemorrhage (aSAH), which may increase the risk of mortality in patients with aSAH. c­Jun N­terminal kinase (JNK) has been demonstrated to be a promoter of EBI­induced cell apoptosis, although the mechanism has yet to be fully elucidated. The present study aimed to explore whether the role of JNK1 is associated with tumor protein p53 (p53), which is one of the most important factor that triggers cell apoptosis. JNK1 expression was downregulated via in vivo small interfering RNA transfection in an aSAH rat model in order to assess differences in the behavior, survival times, morphology and genetics of the experimental animals. The results revealed that JNK1 inhibition improved the neurological scores and survival times of SAH rats by interrupting cascaded neuronal apoptosis. The interruption of EBI­induced neuronal apoptosis may originate from a decrease in the level of p53 phosphorylation and deactivation of the downstream mitochondrial apoptotic pathway. Taken together, these results suggest that JNK1 may be a promising target for improving the prognosis of patients with aSAH.

Regenerative repair of Pifithrin-α in cerebral ischemia via VEGF dependent manner.

Promoting regenerative repair, including neurogenesis and angiogenesis, may provide a new therapeutic strategy for treatment of stroke. P53, a well-documented transcription factor, has been reported to be involved in cerebral ischemia and also serves as an important regulator of vascular endothelial growth factor (VEGF). However, the role of p53 in endogenous regenerative repair after brain ischemia is poorly understood. In this study, we investigated the effects of PFT-α, a specific p53 inhibitor on neurogenesis and angiogenesis improvement and associated signal pathways in rats impaired by cerebral artery occlusion (MCAo). PFT-α induced neuroprotection, reduced infarct volume and neurological functional impairment after ischemic stroke. More importantly, neurogenesis and angiogenesis were greatly enhanced by PFT-α, and accompanied by increased expression of VEGF. Moreover, we got consistent results in neural stem cells (NSCs) isolated from fetal rats. In contrast, application of the anti-VEGF neutralizing antibody (RB-222) partially reversed PFT-α-induced neuroprotection and rescued p53 expression. Noteworthily, inhibition of p53 after ischemic stroke in these rats improved their outcomes via promotion of regenerative repair. In conclusion, PFT-α could serve as a promising therapeutic strategy for ischemic stroke by promoting regenerative repair.

Expression and prognostic value of SFRP1 and ß-catenin in patients with glioblastoma.

The roles of secreted frizzled-related protein-1 (SFRP1) and ß-catenin in human cancer have been widely studied, and it has recently been demonstrated that these proteins are associated with numerous human carcinomas. However, their clinical significance in glioblastoma multiforme (GBM) has not been examined. The current study aimed to analyze the correlation between the expression of SFRP1 and ß-catenin, and clinicopathological characteristics in GBM patients. The expression of SFRP1 and ß-catenin was assessed by immunohistochemistry in 113 samples of GBM and 40 normal brain tissues. Compared with normal brain tissues, GBM tissues exhibited significantly lower expression of SFRP1, and higher expression of ß-catenin (both P<0.05). A Kaplan-Meier analysis revealed that patients with positive SFRP1 expression had a significantly longer overall survival (OS) time relative to those with negative SFRP1 expression (P<0.000), and that patients with positive ß-catenin expression had a shorter OS time than those with negative ß-catenin expression (P<0.000). A multivariate Cox regression analysis indicated that adjuvant treatment, SFRP1 expression and ß-catenin expression were independent prognostic factors for OS (P<0.000, P=0.008 and P=0.001, respectively) in patients with GBM. The current data suggest that expression of SFRP1 and ß-catenin may be considered significant prognostic indicators for patients with GBM.

MicroRNA-133b inhibits cell migration and invasion by targeting matrix metalloproteinase 14 in glioblastoma.

Increasing evidence has suggested that microRNA-133b (miR-133b) is important in regulating the genesis of different types of cancer. However, the effects and the underlying mechanisms of miR-133b in the development of glioblastoma (GBM) remain largely unknown. The aim of the present study was to investigate the role of miR-133b in GBM and to determine the molecular mechanisms underlying its action. Reverse transcription-quantitative polymerase chain reaction was used to measure the expression levels of miR-133b in 21 human GBM samples and 9 normal brain tissue samples. A wound healing assay, and Transwell migration and invasion assays were used to evaluate the effects of miR-133b on cell migration and invasion. Western blotting and a luciferase reporter assay were used to identify the target genes of miR-133b. It was found that miR-133b suppressed GBM cell migration and invasion, and matrix metalloproteinase 14 (MMP14) was identified as a direct target gene. In conclusion, miR-133b may suppress GBM migration and invasion through directly targeting MMP14, highlighting its potential as a novel agent for the treatment of GBM invasion.

Targeting the SMO oncogene by miR-326 inhibits glioma biological behaviors and stemness.

BACKGROUND: Few studies have associated microRNAs (miRNAs) with the hedgehog (Hh) pathway. Here, we investigated whether targeting smoothened (SMO) with miR-326 would affect glioma biological behavior and stemness. METHODS: To investigate the expression of SMO and miR-326 in glioma specimens and cell lines, we utilized quantitative real-time (qRT)-PCR, Western blot, immunohistochemistry, and fluorescence in situ hybridization. The luciferase reporter assay was used to verify the relationship between SMO and miR-326. We performed cell counting kit-8, transwell, and flow cytometric assays using annexin-V labeling to detect changes after transfection with siRNA against SMO or miR-326. qRT-PCR assays, neurosphere formation, and immunofluorescence were utilized to detect the modification of self-renewal and stemness in U251 tumor stem cells. A U251-implanted intracranial model was used to study the effect of miR-326 on tumor volume and SMO suppression efficacy. RESULTS: SMO was upregulated in gliomas and was associated with tumor grade and survival period. SMO inhibition suppressed the biological behaviors of glioma cells. SMO expression was inversely correlated with miR-326 and was identified as a novel direct target of miR-326. miR-326 overexpression not only repressed SMO and downstream genes but also decreased the activity of the Hh pathway. Moreover, miR-326 overexpression decreased self-renewal and stemness and partially prompted differentiation in U251 tumor stem cells. In turn, the inhibition of Hh partially elevated miR-326 expression. Intracranial tumorigenicity induced by the transfection of miR-326 was reduced and was partially mediated by the decreased SMO expression. CONCLUSIONS: This work suggests a possible molecular mechanism of the miR- 326/SMO axis, which can be a potential alternative therapeutic pathway for gliomas.

Raf kinase inhibitor protein (RKIP) inhibits the cell migration and invasion in human glioma cell lines in vitro.

OBJECTIVE: To investigate the effects and the potential mechanisms of RKIP on cell migration, invasion and proliferation in human glioma cell lines in vitro. METHODS: The RKIP over-expressing and RKIP knockdown human U87 glioma cells were used to reveal the effects of RKIP on human glioma cells migration, invasion and proliferation. After the recombinant plasmid pcDNA3.0-RKIP or RKIP-shRNA was transfected into the cell lines U87 by the means of liposome assay, the cells migration, invasion and proliferation were detected by wound healing, Transwell and MTT assay. Then, the levels of RKIP, MMP-3, MMP-9 and HMGA2 mRNA transcription were measured by means of RT-qPCR and levels of proteins expressions were determined using Western blot. RESULTS: The results of MTT assay suggested that the PKIP have little inhibitive effects on glioma cells proliferation (P>0.05). The present paper showed that the migration distances in the group of RKIP-shRNA were markedly increased compared to the pcDNA3.0-RKIP and control. Similarly, the results showed that the numbers of invasion cells in RKIP-shRNA were remarkably increased than the pcDNA3.0-RKIP group and control group. Western blot and RT-qPCR suggested that over-expressions of RKIP lessened the MMP-2, MMP-9 and HMGA2 expression, however, turning down the RKIP expression showed the inverse effects. CONCLUSION: RKIP inhibits the cells migrations and invasions. Meanwhile, RKIP might inhibit the glioma cells through inhibiting MMPs and HMAG2 expression. Therefore, we demonstrated that RKIP is an underlying target for the treatment of glioma.

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.

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.

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.