Loss of PTPRS elicits potent metastatic capability and resistance to temozolomide in glioblastoma.

Glioblastoma (GBM) is the most aggressive brain tumor type with worse clinical outcome due to the hallmarks of strong invasiveness, high rate of recurrence, and therapeutic resistance to temozolomide (TMZ), the first-line drug for GBM, representing a major challenge for successful GBM therapeutics. Understanding the underlying mechanisms that drive GBM progression will shed novel insight into therapeutic strategies. Receptor-type tyrosine-protein phosphatase S (PTPRS) is a frequently mutated gene in human cancers, including GBM. Its role in GBM has not yet been clarified. Here, inactivating PTPRS mutation or deficiency was frequently found in GBM, and deficiency in PTPRS significantly induced defects in the G2M checkpoint and limited GBM cells proliferation, leading to potent resistance to TMZ treatment in vitro and in vivo. Surprisingly, loss of PTPRS triggered an unexpected mesenchymal phenotype that markedly enhances the migratory capabilities of GBM cells through upregulating numerous matrix metalloproteinases via MAPK-MEK-ERK signaling. Therefore, this work provides a therapeutic window for precisely excluding PTPRS-mutated patients who do not respond to TMZ.

Streptomyces albireticuli lung infection managed as a pulmonary air cyst: a case report and literature review.

Streptomyces, the largest genus in the Streptomycetaceae family and a prolific producer of antibacterial drugs, is a saprophytic soil organism that rarely causes invasive infections. Here we report a case of necrotic pneumonia caused by Streptomyces albireticuli in a 75-year-old man who presented with progressive chest tightness and dyspnea. Streptomyces albireticuli was isolated from his bronchoalveolar lavage fluid and identified through whole-genome sequencing (WGS) and phylogenetic analysis. The patient responded satisfactorily to clarithromycin therapy. The findings of this study may enhance our vigilance in identifying visceral infections caused by Streptomyces.

Prediction of Cancer-Specific Survival of Brainstem Glioma in Children Based on Risk Stratification Model.

Objective: To develop and authenticate a risk stratification framework and nomogram for ascertaining cancer-specific survival (CSS) among the pediatric brainstem gliomas. Methods: For patients less than 12 years, according to Surveillance, Epidemiology, and End Results (SEER), information from 1998 to 2016 is found in their databases. The survival outcomes, treatments, and demographic clinicopathologic conditions are scrutinized per the database validation, and training cohorts are divided and validated using multivariate Cox regression analysis. A nomogram was designed, and predominantly, the risk stratification conceptualization engaged selected tenets according to the multivariate analysis. The model's authenticity was substantiated through C-index measure and calibration curves. Results: There are 806 pediatric concerns of histologically concluded brainstem glioma in the research. According to multivariate analysis, age, grade, radiotherapy, and race (with P value < 0.05) depicted independent prognostic variations of the pediatric gliomas. The nomogram's C-index was approximately 0.75 and an accompanied predictive capability for CSS. Conclusion: The nomogram constructed in this glioma's context is the primary predictor of using risk stratification. A combination of nomograms with the risk stratification mechanism assists clinicians in monitoring high-risk individuals and engage targeted accessory treatment.

SARM suppresses glioma progression in GL261 glioma cells and regulates microglial polarization.

Microglia is the major cellular component of glioma mass that promotes glioma growth, invasion, and chemoresistance by releasing inflammatory factors. Sterile alpha and HEAT/Armadillo motif (SARM), a member of the Toll-interleukin-1 receptor (TIR) domain-containing adaptor family, is primarily expressed in the central nervous system. However, the role of SARM in glioma is still undefined. In the present work, we examined the function of SARM in microglial polarization and glioma progression. Our results showed that forced the expression of SARM in GL261 glioma cells inhibited tumor growth, and reduced interleukin (IL)-6 secretion in conditioned media. Silencing of SARM in microglia cells inhibited IL-4-induced M2 polarization, enhanced lipopolysaccharide -induced M1 microglial polarization. Furthermore, overexpression of SARM increased the migration of microglia cells upon TGFß stimulation. These data suggested that SARM is involved in neuro-inflammation and microglia activation. In summary, this study provides novel insight into the mechanisms of microglial polarization.

Morphological and Hemodynamic Risk Factors for the Rupture of Proximal Anterior Cerebral Artery Aneurysms (A1 Segment).

OBJECTIVE: The treatment of unruptured small intracranial aneurysms remains controversial. A distinguishing characteristic of A1 segment aneurysms is that they tend to rupture when they are small, which may be related to their distinctive morphology and hemodynamics. Our study sought to investigate the rupture risk factors of A1 segment aneurysms by analyzing the clinical risk factors, morphology, and hemodynamic characteristics of A1 segment aneurysms. METHODS: We retrospectively enrolled 49 (23 ruptured, 26 unruptured) consecutive patients presenting to our institute with A1 segment aneurysms between January 2010 and March 2020. Independent risk factors associated with the rupture of A1 segment aneurysms were analyzed by multivariate regression analysis in the ruptured group and unruptured group. RESULTS: Clinical risk factors, including age, sex, hypertension, smoking history, and SAH family history revealed no difference between the ruptured and unruptured groups. The ruptured group presented a significantly larger size (Size, P = 0.007), aspect ratio (AR, P = 0.002), size ratio (SR, P = 0.001), bottleneck index (BN, P = 0.016), dome-to-neck ratio (DN, P = 0.001), and oscillatory shear index (OSI) (P = 0.001) than the unruptured group. The normalized wall shear stress (NWSS) of the ruptured aneurysms was lower than the unruptured group (P = 0.001). In the multivariate regression analysis, only SR (OR = 3.672, P = 0.003) and NWSS (OR = 0.474, P = 0.01) were independent risk factors in the A1 segment aneurysm rupture. CONCLUSION: A higher SR and lower NWSS revealed a close connection with the rupture of A1 segment aneurysms in our study, thus providing a reference for clinical decision-making in treating A1 segment unruptured aneurysms.

Successful Treatment With Intrathecal and Intravenous Polymyxin B-Based Combination Against MDR Acinetobacter baumannii Meningitis in Pediatric Patient: A Case Report.

Background: Nosocomial meningitis with multidrug-resistant (MDR) or extensively drug-resistant (XDR) Acinetobacter baumannii is a life-threatening complication in neurosurgery. Treatment of these infections is challenging because of poor penetration of the available antibiotics into the cerebrospinal fluid (CSF). Intrathecal (ITH) or intraventricular (IVT) administration of antibiotics is increasingly used as the last treatment option against MDR/XDR Gram-negative bacteria meningitis not responding to intravenous (IV) regimens. However, pertinent data in pediatric patients is scarce. Case Presentation: A 14-year-old male patient developed meningitis from an MDR strain of A. baumannii following endoscopic endonasal resection of craniopharyngioma. Despite a combination therapy involving IV tigecycline, we observed clinical and bacteriologic failure. The patient was then successfully treated with an ITH and IV polymyxin B-based combination. Quantification of tigecycline and polymyxin B in CSF was performed with two-dimensional high-performance liquid chromatography (2D-HPLC) and HDLC coupled with tandem mass spectrometry (HPLC-MS/MS), respectively. Adverse drug reactions (neurotoxicity and skin hyperpigmentation), probably induced by polymyxin B, were acceptable and reversible. Conclusions: The case illustrates ITH and IV Polymyxin B-based combination is an optimal therapeutic option against MDR A. baumannii meningitis in this pediatric patient. In the future, real-time PK/PD data obtained from patients during ITH/IVT polymyxin B therapy should be required to optimize polymyxin use with maximal efficacy and minimal adverse effects.

Image-driven classification of functioning and nonfunctioning pituitary adenoma by deep convolutional neural networks.

The secreting function of pituitary adenomas (PAs) plays a critical role in making the treatment strategies. However, Magnetic Resonance Imaging (MRI) analysis for pituitary adenomas is labor intensive and highly variable among radiologists. In this work, by applying convolutional neural network (CNN), we built a segmentation and classification model to help distinguish functioning pituitary adenomas from non-functioning subtypes with 3D MRI images from 185 patients with PAs (two centers). Specifically, the classification model adopts the concept of transfer learning and uses the pre-trained segmentation model to extract deep features from conventional MRI images. As a result, both segmentation and classification models obtained high performance in two internal validation datasets and an external testing dataset (for segmentation model: Dice score = 0.8188, 0.8091 and 0.8093 respectively; for classification model: AUROC = 0.8063, 0.7881 and 0.8478, respectively). In addition, the classification model considers the attention mechanism for better model interpretation. Taken together, this work provides the first deep learning-based tumor region segmentation and classification models of PAs, which enables early diagnosis and subtyping PAs from MRI images.

TRPV4 activates the Cdc42/N-wasp pathway to promote glioblastoma invasion by altering cellular protrusions.

The invasion ability of glioblastoma (GBM) causes tumor cells to infiltrate the surrounding brain parenchyma and leads to poor outcomes. Transient receptor potential vanilloid 4 (TRPV4) exhibits a remarkable role in cancer cell motility, but the contribution of TRPV4 to glioblastoma metastasis is not fully understood. Here, we reported that TRPV4 expression was significantly elevated in malignant glioma compared to normal brain and low-grade glioma, and TRPV4 expression was negatively correlated with the prognosis of glioma patients. Functionally, stimulation of TRPV4 promoted glioblastoma cell migration and invasion, and repression of TRPV4 hindered the migration and invasion of glioblastoma cells in vitro. Molecularly, TRPV4 strongly colocalized and interacted with skeletal protein-F-actin at cellular protrusions, and TRPV4 regulated the formation of invadopodia and filopodia in glioblastoma cells. Furthermore, the Cdc42/N-wasp axis mediated the effect of TRPV4-regulated cellular protrusions and invasion. Foremost, TRPV4 inhibitor treatment or downregulation of TRPV4 significantly reduced the invasion-growth of subcutaneously and intracranially transplanted glioblastoma in mice. In conclusion, the TRPV4/Cdc42/wasp signaling axis regulates cellular protrusion formation in glioblastoma cells and influences the invasion-growth phenotype of glioblastoma in vivo. TRPV4 may serve as a prognostic factor and specific therapeutic target for GBM patients.

LEF1-AS1 is implicated in the malignant development of glioblastoma via sponging miR-543 to upregulate EN2.

Glioblastoma (GBM) has been regarded as the most aggressive disease in the nervous system. Accumulating literatures have illustrated the crucial role of competing endogenous RNAs (ceRNAs) network in the pathogenesis and progression of various tumors. The promoting effect of LEF1-AS1 on GBM development has been previously identified. This study attempted to explore the underlying mechanism of LEF1-AS1 in GBM. Data of clinical GBM patients was downloaded from TCGA and GEO databases. The proliferative ability, clonogenic vitality, invasive, and migratory capabilities of GBM cells were measured using Cell counting kit-8 (CCK-8), colony formation and transwell assays. Luciferase reporter gene analysis was performed to verify the correlations between LEF1-AS1/EN2 and miR-543. qRT-PCR and western blotting were implemented to evaluate the mRNA and protein levels, respectively. Our results consolidated that LEF1-AS1 was highly expressed in GBM tissue specimens and its up-regulation induced unfavorable prognosis. The loss/gain-of-function analyses verified that LEF1-AS1 promoted the GBM cell malignant behaviors. Mechanically, LEF1-AS1 acted as a ceRNA for miR-543 and positively regulated engrailed homeobox 2 (EN2) expression. Down-regulation of miR-543 elevated GBM cell malignant behaviors, which was reversed by LEF1-AS1 knockdown. Meanwhile, the LEF1-AS1 inhibition could arrest the promoting effect of high-regulated EN2 on GBM cell aggressiveness and vice versa. In conclusion, our findings identified LEF1-AS1 as a ceRNA for miR-543 and showed that EN2 was positively regulated by LEF1-AS1. The LEF1-AS1/miR-543/EN2, as a novel ceRNA network, was implicated in the progression of GBM, which provided a novel insight for GBM treatment.

Presenilin1 exerts antiproliferative effects by repressing the Wnt/ß-catenin pathway in glioblastoma.

BACKGROUND: Glioblastoma and Alzheimer's disease (AD) are the most common and devastating diseases in the central nervous system. The dysfunction of Presenilin1 is the main reason for AD pathogenesis. However, the molecular function of Presenilin1 and its relative mechanism in glioblastoma remain unclear. METHODS: Expression of presenilin1 in glioma was determined by IHC. CCK-8, colony formation, Flow cytometry, Edu staining were utilized to evaluate functions of presenilin1 on glioblastoma proliferation. The mechanism of above process was assessed by Western blotting and cell immunofluorescence. Mouse transplanting glioblastoma model and micro-MRI detection were used to verified presenilin1 function in vivo. RESULTS: In this study, we found that all grades of glioma maintained relatively low Presenilin1 expression and that the expression of Presenilin1 in high-grade glioma was significantly lower than that in low-grade glioma. Moreover, the Presenilin1 level had a positive correlation with glioma and glioblastoma patient prognosis. Next, we determined that Presenilin1 inhibited the growth and proliferation of glioblastoma cells by downregulating CDK6, C-myc and Cyclin D1 to arrest the cell cycle at the G1/S phase. Mechanistically, Presenilin1 promoted the direct phosphorylation of ß-catenin at the 45 site and indirect phosphorylation at the 33/37/41 site, then decreased the stabilized part of ß-catenin and hindered its translocation from the cytoplasm to the nucleus. Furthermore, we found that Presenilin1 downregulation clearly accelerated the growth of subcutaneous glioblastoma, and Presenilin1 overexpression significantly repressed the subcutaneous and intracranial transplantation of glioblastoma by hindering ß-catenin-dependent cell proliferation. CONCLUSION: Our data implicate the antiproliferative effect of Presenilin1 in glioblastoma by suppressing Wnt/ß-catenin signaling, which may provide a novel therapeutic agent for glioblastoma. Video Abstract.

Mutant-allele tumor heterogeneity in malignant glioma effectively predicts neoplastic recurrence.

Intra-tumor heterogeneity (ITH) is one of the most important causes of therapy resistance, which eventually leads to the poor outcomes observed in patients with glioma. Mutant-allele tumor heterogeneity (MATH) values are based on whole-exon sequencing and precisely reflect genetic ITH. However, the significance of MATH values in predicting glioma recurrence remains unclear. Information of patients with glioma was obtained from The Cancer Genome Atlas database. The present study calculated the MATH value for each patient, analyzed the distributions of MATH values in different subtypes and investigated the rates of clinical recurrence in patients with different MATH values. Gene enrichment and Cox regression analyses were performed to determine which factors influenced recurrence. A nomogram table was established to predict 1-, 2- and 5-year recurrence probabilities. MATH values were increased in patients with glioma with the wild-type isocitrate dehydrogenase (NADP(+)) (IDH)1/2 (IDH-wt) gene (P=0.001) and glioblastoma (GBM; P=0.001). MATH values were negatively associated with the 2- and 5-year recurrence-free survival (RFS) rates in patients with glioma, particularly in the IDH1/2-wt and GBM cohorts (P=0.001 and P=0.017, respectively). Furthermore, glioma cases with different MATH levels had distinct patterns of gene mutation frequencies and gene expression enrichment. Finally, a nomogram table that contained MATH values could be used to accurately predict the probabilities of the 1-, 2- and 5-year RFS of patients with glioma. In conclusion, the MATH value of a patient may be an independent predictor that influences glioma recurrence. The nomogram model presented in the current study was an appropriate method to predict 1-, 2- and 5-year RFS probabilities in patients with glioma.

Apoptosis induction effect of Apocynum venetum polyphenol on human U87 glioma cells via NF-κB pathway.

Aim: Apocynum venetum polyphenol (AVP) was used in in vitro glioma cells culture to prove the growth inhibitory effect of AVP on human U87 glioma cells via NF-κB pathway. Materials & methods: The MTT assay, DAPI morphology, quantitative PCR and western blot experiments were used for determination in vitro. Results & conclusion: AVP can also induce U87 cancer cells apoptosis illustrated by DAPI morphology. AVP could enhance the mRNA and protein expression of IκB-α, TNF-α, TRAIL, caspase-3 and caspase-9 in U87 cancer cells and reduce those of NF-κBp65, cIAP-1, cIAP-2, TGF-ß2, CyclinD1, VEGF and IL-8. After ammonium pyrrolidine dithiocarbamate (PDTC) treatment, the NF-κBp65 expression was reduced in U87 cells, and AVP could raise these effects. The results of HPLC indicate that AVP mainly contains six constituents. The growth inhibitory effects of AVP on U87 glioma cells are predominantly from these natural active constituents.

High expression of the transcriptional coactivator TAZ is associated with a worse prognosis and affects cell proliferation in patients with medulloblastoma.

The transcriptional coactivator tafazzin (TAZ) serves pivotal roles in organ development, tumor initiation and tumor progression. However, to the best of our knowledge, the expression of TAZ and its clinical significance in human medulloblastoma have not been defined. The present study aimed to clarify the clinical and biological significance of TAZ expression in human medulloblastoma. Immunohistochemical staining for TAZ was performed with 72 medulloblastoma and three normal brain tissue samples. A high expression level of TAZ was detected in 65.28% of medulloblastoma tissues, whereas low expression was identified in the normal brain tissues. TAZ expression was significantly associated with medulloblastoma recurrence. However, the expression of TAZ was not associated with sex, age, tumor location, tumor maximal diameter and tumor histology. Furthermore, both the overall survival and tumor-free survival rate of patients with high levels of expression of TAZ were shorter compared with those of patients with tumors expressing low levels of TAZ. In univariate and multivariate Cox regression analyses, TAZ expression was identified as a significant prognostic factor for patients with medulloblastoma. Functionally, downregulation of TAZ inhibited the proliferation and tumor formation of medulloblastoma cells and the expression of cell-cycle associated proteins in Daoy cells. In conclusion, high expression of TAZ may serve as a prognostic marker for patients with medulloblastoma and TAZ may be a potential target for medulloblastoma therapy.

Long Non-Coding RNA Plasmacytoma Variant Translocation 1 (PVT1) Enhances Proliferation, Migration, and Epithelial-Mesenchymal Transition (EMT) of Pituitary Adenoma Cells by Activating ß-Catenin, c-Myc, and Cyclin D1 Expression.

BACKGROUND As a kind of benign tumor, pituitary adenomas have attracted increasing attention from researchers. The plasmacytoma variant translocation 1 (PVT1) is a molecule in the lncRNA family protein that has been proven to play critical roles in many cancers; however, no study has explored the special biological roles of PVT1 in pituitary adenoma. MATERIAL AND METHODS The qRT-PCR assay was conducted to evaluate PVT1 expressions in various cell lines and tissues. Loss of function assays were carried out to detect the influence of silenced PVT1 on the proliferation, migration, and epithelial-mesenchymal transition (EMT) of pituitary adenoma cells. Western blotting was used to identify correlation between ß-catenin and PVT1. RESULTS The PVT1 expressions were significantly enhanced in tissues of pituitary adenoma and cancer cells. Cell migration and proliferation were inhibited when the PVT1 gene was knocked down. Knockdown of PVT1 repressed the migration and EMT of pituitary adenoma cells. The PVT1 downregulation obviously blocked Wnt/ß-catenin signaling pathway activity. PVT1 aggravated progression of pituitary adenoma through initiating the Wnt/ß-catenin signaling pathway. CONCLUSIONS PVT1 exerts an oncogenic role through activating Wnt/ß-catenin signaling in pituitary adenoma cells. The present results may provide a potential therapeutic target or approach for treating pituitary adenomas.

The long-term clinical outcomes of microvascular decompression for treatment of trigeminal neuralgia compressed by the vertebra-basilar artery: a case series review.

BACKGROUND: Microvascular decompression (MVD) is a type of neurosurgery used to treat trigeminal neuralgia (TN) caused by the vertebrobasilar contact/compression. The surgery is not risk-free, however; it may cause recurrent facial pain or other side-effects. The objective of this study was to assess the long-term pain relief and the complications of MVD surgery for the vertebrobasilar compression treatment. METHODS: Twenty-three patients with TN compressed by the vertebra-basilar artery (VBA) were treated with MVD. Teflon felt was placed between the brain stem and the offending artery to mobilize the artery towards the skull base and the clivus. The Barrow Neurological Institute (BNI) Pain Intensity Scale score was used to assess pre- and post-surgical pains. RESULTS: Of 23 patients with pre-operative BNI IV to V, 19 patients (83%) were pain-free after surgery. Four patients experienced transient partial pain relief with BNI II-III, and 3 of them (13%) were completely pain-free within 3 months. The success rate was 96%. Three patients (13%) had pain recurrences, and one received a second MVD surgery for pain relief during the period of follow-up. Four patients suffered from TN hypesthesia, and only 2 patients (8.6%) had permanent facial hypesthesia, while one patient (4.3%) developed a gradual hearing loss after surgery. CONCLUSIONS: While our success rate of immediate pain relief after surgery was comparable with some reports, the percentage of patients who had pain recurrences was lower, and cases who had permanent facial hypesthesia or developed a gradual hearing loss were fewer after MVD surgery. Our rate of transient complications was higher, and the postoperative pain relief seemed unusually delayed. Our study indicates that MVD is an effective, reliable, and safe neurosurgery for treatment of TN compressed by the VBA albeit our small sample size. Failure of treatment and recurrence of the disease as well as complications could be minimized by preventing displacement of the Teflon implant and extraneous Teflon touching the trigeminal nerves.

Case Report of Late Type IIIb Endoleak with Willis Covered Stent (WCS) and Literature Review.

OBJECTIVE: We report a case of late type IIIb endoleak with Willis covered stent (WCS) developed 14 months after endovascular paraclinoid aneurysm repair. METHODS: A 52-year-old woman presented with episodic headache, caused by a giant paraclinoid aneurysm. She underwent a successful 3.5 x 16mm WCS positioning to treat the aneurysm. Fourteen months later, the patient was admitted with the same symptoms. Digital subtraction angiography examination showed recurrence of the aneurysm, which was similar to the preoperative one. DynaCT (Siemens, Erlangen, Germany) indicated the intact of the metal structure of the stent without migration. Type IIIb endoleak (defect in the graft fabric) was confirmed with a whole aneurysm neck located in the middle part of the stent. The type IIIb endoleak was treated with another WCS (4.0 x 16mm). The immediate digital subtraction angiography imaging indicated that the endoleak disappeared and the aneurysm was completely occluded. Re-examination done 1 year after the second treatment showed a complete exclusion of the aneurysm sac. CONCLUSIONS: Type IIIb endoleaks can be safely treated by the endovascular positioning of another WCS. Continuous surveillance after endovascular paraclinoid aneurysm repair for intracranial aneurysms is warranted to make ensure the safety of WCS.

Inhibition of MicroRNA-195 Alleviates Neuropathic Pain by Targeting Patched1 and Inhibiting SHH Signaling Pathway Activation.

Trigeminal neuralgia (TN) is a type of chronic neuropathic pain that is caused by peripheral nerve lesions that result from various conditions, including the compression of vessels, tumors and viral infections. MicroRNAs (miRs) are increasingly recognized as potential regulators of neuropathic pain. Previous evidence has demonstrated that miR-195 is involved in neuropathic pain, but the mechanism remains unclear. To investigate the pathophysiological role of miR-195 and Shh signaling in TN, persistent facial pain was induced by infraorbital nerve chronic constriction injury (CCI-IoN), and facial pain responses were evaluated by Von Frey hairs. qPCR and Western blotting were used to determine the relative expression of miR-195 and Patched1, the major receptor of the Sonic Hedgehog (Shh) signaling pathway, in the caudal brain stem at distinct time points after CCI-IoN. Here, we found that the expression of miR-195 was increased in a rat model of CCI-IoN. In contrast, the expression of Patched1 decreased significantly. Luciferase assays confirmed the binding of miR-195 to Patched1. In addition, the overexpression of miR-195 by an intracerebroventricular (i.c.v) administration of LV-miR-195 aggravated facial pain development, and this was reversed by upregulating the expression of Patched1. These results suggest that miR-195 is involved in the development of TN by targeting Patched1 in the Shh signaling pathway, thus regulating extracellular glutamate.

Sortilin promotes glioblastoma invasion and mesenchymal transition through GSK-3ß/ß-catenin/twist pathway.

High aggressiveness is a hallmark of glioblastoma and predicts poor prognosis of patients with glioblastoma. The expression level of sortilin has been preliminarily reported to be elevated in high-grade glioma; however, the potential significance of sortilin in glioblastoma progression has not been elucidated. In this study, we investigated the oncogenic effect of sortilin in glioblastoma. Increased levels of sortilin were noted in the mesenchymal subtype of glioblastoma and highly aggressive subtypes of glioblastoma tissues and cell lines. In addition, high levels of sortilin predicted poor prognoses in patients with glioblastoma. Sortilin knockdown or inhibition with AF38469 (an orally bioavailable inhibitor of sortilin) significantly suppressed migration and invasion by inhibiting EMT-like mesenchymal transition in glioblastoma cells. Furthermore, we proved that sortilin promoted cell invasion mainly via Glycogen synthase kinase 3 beta (GSK-3ß)/ß-catenin/Twist-induced EMT-like mesenchymal transition in glioblastoma. Taken together, our results demonstrate a critical role of sortilin in glioblastoma invasion and EMT-like mesenchymal transition, indicating that sortilin contributes to glioblastoma progression. These data also highlight the dramatic antitumor effects of AF38469 in glioblastoma, suggesting that AF38469 is a potentially powerful antitumor agent for sortilin-overexpressing human glioblastoma.

Effect and molecular mechanism of mTOR inhibitor rapamycin on temozolomide-induced autophagic death of U251 glioma cells.

Glioma is a malignant tumor of the glial tissue that is difficult to excise through surgery, with poor patient prognosis. The use of chemotherapeutic drugs alone to treat glioma following surgery results in a high probability of sequelae, such as tumor recurrence. The present study investigated the effects of a novel treatment combination on glioma cells and determined the molecular mechanisms underlying its action. The effect of temozolomide (TMZ) combined with rapamycin (RAPA) on the TMZ-induced autophagic death of U251 glioma cells was examined. The U251 cell line was treated with TMZ combined with RAPA, and the cell survival rate and half maximal inhibitory concentration (IC50) of TMZ/RAPA was detected using the Cell Counting Kit-8 (CCK-8) assay. Flow cytometry was used to detect changes in cell cycle distribution. The formation of acidic vesicular organelles (AVOs) in the cytoplasm was identified using fluorescence microscopy and quantitatively analyzed. Western blotting was performed to detect the expression levels of autophagy-associated proteins Beclin-1 and microtubule associated protein 1 light chain 3 alpha (MAP1LC3A)-I and II. RAPA (1.25 nM) combined with 5 µM TMZ markedly inhibited U251 cell growth. RAPA reinforced TMZ-induced autophagic death, reducing the IC50 value of treatment when combined (TMZ alone, 22.5±3.23 µM vs. TMZ and RAPA, 10.35±2.81 µM). Compared with the control group, the proportion of cells in G2/M were markedly increased following treatment with TMZ combined with RAPA. Acridine orange staining demonstrated that TMZ combined with RAPA could markedly enhance the generation of intracellular AVOs compared with TMZ or RAPA alone. In addition, Beclin-1 and LC3-II protein expression was markedly increased compared with the control and single treatment groups (P<0.05). The results of the present study indicate that RAPA reinforces TMZ-induced autophagic death of U251 glioma cells, providing a novel therapeutic combination for the treatment of malignant glioma.