Long noncoding RNA FOXD2-AS1 promotes glioma cell cycle progression and proliferation through the FOXD2-AS1/miR-31/CDK1 pathway.

Long noncoding RNAs (lncRNAs) are vital mediators involved in cancer progression. Previous studies confirmed that FOXD2 adjacent opposite strand RNA 1 (FOXD2-AS1) is upregulated in tumor diseases. The potential influence of FOXD2-AS1 in glioma progression, however, remains unknown. In this paper, FOXD2-AS1 was found to be upregulated in glioma tissues. Its level was linked with glioma stage. Moreover, glioma patients expressing high level of FOXD2-AS1 suffered worse prognosis. Biological functions of FOXD2-AS1 in glioma cells were analyzed through integrative bioinformatics and TCGA RNA sequencing data analysis. Pathway enrichment analysis uncovered that FOXD2-AS1 was mainly linked with cell cycle regulation in both low-grade glioma and glioblastoma. Further experiments demonstrated that silence of FOXD2-AS1 inhibited proliferation, arrested cell cycle and downregulated cyclin-dependent kinase 1 (CDK1) in human glioma cells. Dual-luciferase reporter assay confirmed that FOXD2-AS1 upregulated CDK1 by sponging miR-31. Rescue assays were performed and confirmed the regulatory loop FOXD2-AS1/miR-31/CDK1 in glioma. Collectively, our results indicated that the FOXD2-AS1/miR-31/CDK1 axis influenced glioma progression, providing a potential new target for glioma patients.

Impact of Intraoperative Blood Pressure Control and Temporary Parent Artery Blocking on Prognosis in Cerebral Aneurysms Surgery.

Objective In cerebral aneurysm clipping and embolization, blood pressure control and temporary parent artery blocking are common methods to prevent aneurysm rupture. Their influence on the prognosis is uncertain. In this study, we try to find out the association between methods above and prognostic indicators.Methods We held a retrospective analysis on patients' medical records of cerebral aneurysms surgical clipping and endovascular coiling , and recorded gender, age, diagnosis, Hunt-Hess grade, Glasgow coma scale score, treatment methods, a history of hypertension, preoperative systolic blood pressure, with or without controlled hypotension, systolic blood pressure difference before and after controlled hypotension, with or without temporary artery blocking, with or without hypertension after treated aneurysm, prognostic indicators including mortality after 1 month, intensive care unit (ICU) stay time of survivors, discharged Glasgow outcome scale (GOS) score. Prognostic indicators were regarded as dependent variable, all the factors were regarded as independent variable, and the strength analysis of influence factors on prognostic indicators was made by binary logistic regression.Results Total cases were 165, including 68 males and 97 females, with an average age of 56 (12-85) years. The mortality after 1 month was 10.9% (18 cases). The ICU stay time of survivors was 7.35 (0-67) days. GOS score at discharge was 1-3 in 40 (24.2%) patients and 4-5 in 125 (75.8%) patients. Systolic blood pressure difference before and after controlled hypotension was an independent factor influencing mortality (t=2.273, P=0.024), and the greater the difference was, the higher the mortality would be. Timely hypertension after aneurysm treated was an independent factor affecting ICU stay time of survivors and patients with hypertension had shorter ICU stay time (χ2=10.017, P=0.001). Blood pressure control (χ2=0.088, P=0.767) and temporary blocking (χ2=1.307, P=0.253) did not show significant influence on GOS score at discharge.Conclusions Timely controlled hypertension after aneurysm clipping and embolization can significantly shorten the stay time in ICU. The degree of controlled hypotension associates with postoperative mortality, the greater systolic blood pressure difference before and after antihypertensive treatment is, the higher the mortality will be.

Resection or Biopsy: The Efficacy of Different Surgical Approaches for Primary Central Nervous System Lymphoma.

AIM: To analyze the efficacy of surgical resection versus brain biopsy combined with postoperative chemotherapy for primary central nervous system lymphoma (PCNSL) and to discuss a clinically standardized treatment protocol. MATERIAL AND METHODS: Patients with a pathological diagnosis of PCNSL and subsequent chemotherapy between 2016 and 2021 at Northern Jiangsu People?s Hospital were selected and divided into groups according to whether they underwent microsurgical resection or stereotactic needle biopsy. Statistical analyses were performed to compare efficacy and safety in the two groups. RESULTS: A total of 21 patients with PCNSL were identified, of whom 12 underwent resection and 9 underwent diagnostic stereotactic biopsy only. Compared with the resection group, the biopsy group had a higher proportion of deep tumors (55.6% vs. 8.3%, p=0.016), and the mean intraoperative bleeding was significantly reduced (13.33 ± 6.61 mL vs. 170.83 ± 101.04 ml, p < 0.001). In addition, the mean survival time of patients who died during the postoperative follow-up period was shorter (6.83 ± 1.60 vs. 18.56 ± 10.20 months, p=0.016), and the one-year survival rate was lower (33.3% vs. 83.3%, p=0.032). There was no significant difference between the two groups in terms of the mean progression-free survival time or new functional impairment after surgery. CONCLUSION: For PCNSL, patients who undergo surgical resection have a better outcome than those who undergo biopsy only, suggesting that when the tumor is located at a surgically resectable site, surgical resection should be actively chosen; when the tumor is located at a deep and unresectable site, brain biopsy should be chosen.

TCF3 Induces DNMT1 Expression to Regulate Wnt Signaling Pathway in Glioma.

The epigenetic alteration is widely understood as the key to cancer initiation. Herein, we intended to clarify the role of transcription factor 3 (TCF3) in the development of glioma and the behind epigenetic mechanism. Through bioinformatics analysis, we identified a TCF3-DNA methyltransferase 1 (DNMT1)-secreted frizzled related protein 1 (SFRP1) axis which was differentially expressed and interacted in gliomas. More specifically, TCF3 activated DNMT1 transcription, and DNMT1 repressed SFRP1 expression. TCF3 and DNMT1 were overexpressed, while SFRP1 was downregulated in glioma. Functionally, TCF3 silencing inhibited cell proliferation and migration, and promoted apoptosis, which were reversed by DNMT1. SFRP1 inhibited the tumor supporting effects of DNMT1 on glioma cells. Moreover, TCF3 downregulation or SFRP1 overexpression inhibited tumorigenesis and enhanced apoptosis of glioma cells, while DNMT1 enhanced tumorigenesis and repressed apoptosis in tumor tissues in vivo. The Wnt pathway was a downstream effector of the TCF3-DNMT1-SFRP1 axis. Collectively, this study determined a novel therapeutic target TCF3 for glioma from the perspective of epigenetic alteration via regulation of SFRP1 expression in a DNMT1-dependent manner.

Minimally Invasive Surgery in Chronic Subdural Hematoma: Prognosis and Recurrence Factors of 516 Cases in a Single Center.

Objective: To investigate the effects of minimally invasive surgery (MIS) using a novel YL-1 puncture needle and summarize the risk factors of recurrence in chronic subdural hematoma (CSDH). Methods: We performed a retrospective analysis in 516 hospitalized patients with CSDH from January 2013 to December 2018 in Northern Jiangsu People's Hospital. Patients' gender, age, history of trauma, use of anticoagulants, history of disturbed liver or renal function, history of heart disease, history of malignant tumor, history of diabetes, hemodialysis, coagulopathy, alcoholism, imaging indicators, and postoperative application of urokinase or atorvastatin were recorded. Recurrence is defined by imaging examination with or without clinical presentation three months after discharge. Results: In total, 483 patients (93.60%) benefited from MIS by YL-1 needle. Gender, age, history of head trauma, history of disturbed liver function, history of heart disease, history of malignant tumor, history of diabetes, history of hemodialysis, coagulopathy, alcoholism, hematoma location, hematoma densities, septum formation, maximum thickness, encephalatrophy, and use of atorvastatin and urokinase were shown to be non-significantly associated with postoperative recurrence (p > 0.05). The use of anticoagulants was significantly associated with postoperative recurrence (p > 0. 05). Logistic analysis showed that the use of anticoagulants is an independent factor predicting postoperative recurrence (p > 0. 05). Conclusions: The novel YL-1 puncture needle turned out to be a safe and effective minimally invasive surgery, and the use of anticoagulants is an independent risk factor predicting postoperative recurrence in CSDH, which can provide MIS and early therapeutic strategies for neurosurgeons.

Comparison of Neuroendoscopic and Microscopic Surgery for Unilateral Hemilaminectomy: Experience of a Single Institution.

Objective: This study was designed to compare the safety and efficacy of unilateral hemilaminectomy conducted under complete neuroendoscopic visualization (UHNV) relative to unilateral hemilaminectomy under total microscopic visualization (UHMV) for the treatment of patients diagnosed with intraspinal tumors. Methods: In total, 41 patients undergoing intraspinal tumor resection at Northern Jiangsu People's Hospital were included in this study, including 20 and 21 patients in the UHNV and UHMV groups, respectively. Intraoperative parameters including incision length, operative duration, number of vertebral laminae removed and intraoperative blood loss, as well as indicators of curative efficacy such as total tumor resection rates and postoperative symptom improvement rates, and safety indicators including complication rates, recurrence rates, spinal deformity rates, spinal instability incidence, and length of stay (LOS), were compared between the two groups. Results: In contrast to the UHMV group, patients in the UHNV group had a significantly shorter incision length and decreased intraoperative blood loss (P < 0.05), while the operative duration (P > 0.05) showed no statistical difference. Although the postoperative improvement and total tumor resection rates were enhanced, the difference was not statistically significant (P > 0.05). In comparison, the bedridden time and length of stay (LOS) were significantly shortened (P < 0.05) in the UHNV group. However, there were no significant differences in recurrence, incidence of complications, spinal deformity, and spinal instability (P > 0.05). Conclusion: Collectively, our findings indicate that UHNV is not inferior to the UHMV approach. Moreover, due to its safe and minimally invasive nature, UHNV represents a promising alternative to UHMV as a treatment for patients with intradural extramedullary tumors.

Effect of Twist-Drill Craniostomy With Hollow Screws for Evacuation of Chronic Subdural Hematoma: A Meta-Analysis.

OBJECTIVE: This study systematically reviews the clinical efficacy and safety of twist-drill craniostomy with hollow screws in chronic subdural hematoma treatment. METHODS: A computerized search of PubMed, Embase, Web of Science, Cochrane Library, World Health Organization International Trial Registry platform, CBM, CNKI, and Wanfang Database was performed to retrieve randomized controlled trials or case-control trials using twist-drill craniostomy (TDC) with hollow screws for the evacuation of chronic subdural hematoma from the date of databases' inception to July 2021. Two investigators independently screened the studies and extracted data in strict accordance with pre-established inclusion and exclusion criteria. RevMan 5.3 software or STATA was used for meta-analysis after evaluating the methodological quality of the included studies. RESULTS: A total of 4 randomized controlled trials and 16 case-control trials with a total of 2,536 cases were included. Results of the meta-analysis showed that the surgical success rate and postoperative recurrence rate of TDC with hollow screws were slightly higher compared to the burr hole craniostomy (BHC) group, but showed no statistical significance (RR = 1.03, P = 0.05; RR = 1.13, P = 0.50). However, subgroup analysis showed that the use of YL-1 needle had a higher success rate and lower recurrence rate (RR = 1.05, P = 0.02 < 0.05; RR = 0.584, P = 0.002), and TDC with hollow screws had a lower incidence rate of postoperative complications and postoperative acute intracranial hemorrhage compared with BHC, also revealing an overall shorter hospital stay (RR = 0.57, P = 0.0002 < 0.05; RR = 0.584, P = 0.027 < 0.05; WMD = -3.752, P < 0.001). However, the postoperative mortality rate was practically the same between the two groups (OR = 1.01, P = 0.95 > 0.05). CONCLUSION: Twist-drill craniostomy with hollow screws is not inferior or superior to BHC in efficacy, and this strategy is safer and minimally invasive, which is reflected in a lower incidence of acute intracranial hemorrhage, overall complication rate, and length of hospital stay. SYSTEMATIC REVIEW REGISTRATION: https://www.crd.york.ac.uk/prospero/, identifier: CRD42021270835.

Eliminating vascular interference from the Spot Sign contributes to predicting hematoma expansion in individuals with spontaneous cerebral hemorrhages.

The computed tomography angiography (CTA) Spot Sign is an effective means of predicting hematoma expansion (HE) in the context of spontaneous intracerebral hemorrhage (ICH). We investigated whether continuous CTA source images could differentiate the Spot Sign and blood vessels in the hematoma, and whether it would improve Spot Sign accuracy as an HE predictor. We screened for the presence of CTA Spot Sign in individuals affected by spontaneous ICH within 24 h of symptom development. Based on our findings, we determined the sensitivity, specificity, and positive/negative predictive values of this sign as a predictor of HE both on its own and following the exclusion of blood vessels. In addition, a receiver-operating characteristic approach was used to assess the accuracy of Spot Sign with and without elimination of vascular interference. A total of 265 patients were included in this study. The Spot Sign was observed in 100 patients, including in 29 patients wherein it was confirmed to be blood vessels as determined based upon continuous CTA source images. With respect to predicting HE, Spot Sign sensitivity, specificity, positive predictive values, and negative predictive values were 57%, 71%, 48% and 78%, respectively. Following the exclusion of blood vessels, these values were 57%, 87%, 68% and 81%, respectively. Spot Sign area under the curve after excluding blood vessels was 0.718, which was higher than that of the Spot Sign (0.638). After continuous CTA, source images are used to exclude blood vessels in the hematoma, the Spot Sign is thus more accurate in predicting HE.

The effect of atorvastatin on recurrence of chronic subdural hematoma after novel YL-1 puncture needle surgery.

OBJECTIVE: Chronic subdural hematoma (CSDH) is a common neurological disorder with a high recurrence rate. This study investigates the effect that atorvastatin has when used as a postoperative adjuvant therapy on the prevention of CSDH recurrence after YL-1 puncture needle surgery. PATIENTS AND METHODS: A retrospective analysis of 516 CSDH patients who underwent YL-1 puncture needle surgery was undertaken. Baseline characteristics including sex, age, history of injury, past medical histories (anticoagulation, liver dysfunction, heart diseases, malignant tumors, diabetes, hemodialysis, and chronic alcoholism), and computed tomography (CT) or magnetic resonance imaging (MRI) diagnostic indicators (bilateral, mixed density or signal, maximum hematoma width, and brain atrophy) were recorded. Differences in recurrence rates were compared between two groups: one with atorvastatin after surgery and one without. RESULTS: 516 patients (429 men and 87 women), aged 14-98 years (mean age, 67.09 ± 11.74 years) were included in the study. YL-1 puncture needle surgery was performed 610 times. 94 patients had bilateral surgery, totaling 184 procedures. 301 patients with 360 procedures were treated with atorvastatin after surgery, of which 25 had recurrent CSDH; recurrence rate: 7.0 % (25/360). 215 patients with 250 procedures had surgery without subsequent atorvastatin, of which 14 had recurrent CSDH; recurrence rate: 5.6 % (14/250). Univariate analysis indicated no statistically significant difference in recurrence rates between groups (P > 0.05). Baseline characteristics of the two groups (age, sex, history of injury, past medical histories, CT or MRI diagnostic indicators) also showed no statistical difference (all P > 0.05). CONCLUSIONS: YL-1 puncture needle surgery with irrigation and closed-system drainage is an effective surgical treatment for CSDH. Atorvastatin has no statistically significant effect on the prevention of CSDH recurrence after surgery.

[The construction of lentivirus-mediated RNAi vector containing hTERT].

OBJECTIVE: To construct a recombinant lentivirus RNA interference (RNAi) vector carrying hTERT gene, and to obtain the titer of the lentiviral stock for investigating the expression in the eukaryotic cells and the effect on the hTERT gene silencing in the eukaryotic cells. METHODS: Two complimentary oligos of small interference RNA (siRNA) with hairpin structures targeting the hTERT gene and a negative control were synthesized, then ligated with pLVTHM vector and sequenced. The recombinant vectors were then transfected with viral packaging mix into T293 cells, viral supernatant was harvested to determine the titer. U87 cells infected by virus were harvested and the expression of hTERT, telomerase activity and apoptosis were detected by reverse transcription-PCR(RT-PCR), TRAP assay and flow cytometry separately. RESULTS: Sequencing data showed that the constructed plasmids contained the correct sequences of hTERT siRNA transcript templates. A vector producing cell line T293 was established, and the titer for transfection was obtained. RT-PCR and TRAP flow cytometry analyses demonstrated that hTERT shRNA expression construct could suppress the expression of hTERT and telomerase activity and induce apoptosis. CONCLUSION: A lentivirus RNAi vector targeting hTERT gene was successfully constructed, which decreased the expression of hTERT and telomerase activity effectively and induced apoptosis. It has set up a research platform for the gene therapy of tumors which take hTERT as the target.

Lentiviral vector mediated siRNA knock-down of hTERT results in diminished capacity in invasiveness and in vivo growth of human glioma cells in a telomere length-independent manner.

Glioma cells are characterized by their invasiveness and resistance against conventional therapeutics. Telomerase activity has been suggested to be an important target for glioma treatment. Here we assessed the anticancer effects and its potential mechanisms of lentiviral vector mediated siRNA knock-down of the human telomerase reverse transcriptase (hTERT) in U87MG human glioblastoma cells. Stable expression of anti-hTERT siRNA reduced the hTERT expression and TRAP assay telomerase activity to barely detectable levels. Injection of lentiviral vectors encoding anti-hTERT siRNA significantly inhibited the growth of pre-established macroscopic xenograft tumors, which was in contrast to the finding that no obvious effects on cell growth, cell cycle progression and telomere length were observed in anti-hTERT siRNA expressing U87MG cells during short-term in vitro cultures. The in vivo glioma growth inhibition effect was already evident in the period coincided with no detectable telomere length changes, suggesting that hTERT inhibition may hinder glioma cell growth in a telomere length-independent manner. Importantly, transwell migration assay showed profound inhibitory effect on the invasive capacity of U87MG cells following short-term anti-hTERT siRNA expression. Thus, efficient knock-down of hTERT can inhibit glioma cell proliferation and migration prior to its effect on telomere length.

[Study on combined gene therapy for malignant gliomas transfected with antisense hTERT/PTEN in vitro and in vivo].

OBJECTIVE: To study inhibitory efficacy of combined gene therapy for malignant gliomas transfected with antisense human telomerase reverse transcriptase (hTERT)/PTEN in vitro and in vivo. METHODS: To construct two adenovirus recons which contained antisense hTERT and wild-type PTEN respectively with high performance homologous recombination system in bacteria. The two adenovirus recons were transfected into U251 human malignant glioma cells combinedly or respectively in vitro and in vivo. U251 cell proliferation in vitro was determined by MTT assay and flow cytometry, tumor growth in vivo was measured by the volume of glioma in nude mice. Telomerase activity was detected by telomeric repeat amplification protocol (TRAP) assay. Expression of hTERT and PTEN protein was detected by Western blotting methods. RESULTS: After transfection in vitro, the growth of U251 cells was inhibited significantly. The inhibitory effect was time-dependent. The strongest inhibition was observed in combined transfection group, at the 6th day, the survival rate was 37.6%, telomerase activity (only 28.8TPG) was inhibited significantly, hTERT protein expression was inhibited significantly too, which was 0.2106, but PTEN protein expression was increased significantly, which was 0.9630. In vivo, the growth of tumors was also effectively inhibited. CONCLUSION: Growth of malignant glioma cells is effectively inhibited after transfection with combined antisense hTERT and PTEN in vitro and in vivo.

Effects of Atorvastatin on Conservative and Surgical Treatments of Chronic Subdural Hematoma in Patients.

OBJECTIVE: To investigate effects of atorvastatin on conservative and surgical treatment of patients with chronic subdural hematoma. METHODS: A retrospective analysis was performed of 109 patients (including 3 outpatients) with chronic subdural hematoma at Northern Jiangsu People's Hospital from April 2014 to October 2015. Patients' gender, age, Glasgow Coma Scale score, symptoms, history of antiplatelet or anticoagulant use, hematoma location, volume of hematoma, operation methods, and application of atorvastatin and its duration were recorded. Prognostic indicators including changes in hematoma volume and neurologic status were extracted. Statistical methods were conducted to evaluate drug efficacy. RESULTS: Seven conservative patients received atorvastatin for 1-6 months (range, 3.57 ± 1.72 months). The volume of hematomas was ± 4.49 mL to 11.40 ± 4.46 mL (P > 0.05) after 1 month's atorvastatin treatment. Hematomas disappeared after 6 months in all 7 patients. In surgical patients, gender (P = 0.797), age (P = 0.063), Glasgow Coma Scale score (P = 0.216), history of antiplatelet or anticoagulant (P = 0.350), volume of hematoma after admission (P = 0.896), location (P = 0.282), and operation methods (P = 0.832) were nonsignificantly associated with follow-up groups, but atorvastatin was significantly associated with follow-up results (P = 0.045). CONCLUSIONS: Atorvastatin has preliminarily been proved to be safe and effective for chronic subdural hematomas in both conservative and surgical patients and can provide a drug treatment strategy for neurosurgeons.

Transfer of three transcription factors via a lentiviral vector ameliorates spatial learning and memory impairment in a mouse model of Alzheimer's disease.

Alzheimer's disease (AD) is an irreversible and progressive neurodegenerative disorder with observable memory impairment. The present study was performed to evaluate the beneficial effects of lentiviral vector-mediated overexpression of a combination of three transcription regulators, ABN (Ascl1, Brn2 and Ngn2), on learning and memory loss in a mouse model of AD. The AD model was established by injecting Aß1-42 bilaterally into the mouse hippocampus. Lentiviral ABN was delivered bilaterally into the hippocampus of mice. Animals injected with LV-ABN showed significantly improved spatial learning and memory in the water maze test. Additionally, antibody array analysis indicated that intrahippocampal LV-ABN delivery significantly altered the expression levels of some proteins that were identified as inflammatory factors or neuroprotective and growth factors. In conclusion, our data suggest that LV-ABN delivery can ameliorate spatial learning and memory impairment in an AD mouse model, and the beneficial effect of ABN gene treatment could be linked to inhibition of the neuroinflammatory response and enhancement of neuroprotection and neurogenesis. Thus, these findings indicate that lentiviral ABN gene delivery has potential therapeutic applications for AD.

Risk of renal cancer in liver transplant recipients: A systematic review and meta-analysis.

Liver transplantation is associated with a significantly increased risk of de novo malignancies, but for renal cancer this risk is less clear. We therefore performed a meta-analysis of published studies to determine whether renal cancer risk in liver transplant recipients (LTRs) was increased. To obtain a more precise conclusion, a systematic search was performed in PubMed and Web of Science databases until June 10, 2015. Standardized incidence ratio (SIR) corresponding 95% confidence interval (CI) were used to estimate risk of renal cancer in LTRs. Heterogeneity test, sensitivity analysis, and publishing bias were also performed. We identified 8 eligible studies and performed a meta-analysis on data of 49,654 LTRs with a total follow-up of 121,514.6 patient-years. The SIR for renal cancer was identified a 3.275-fold higher SIR (95% CI: 1.857-5.777; P < 0.001) in LTRs compared with the general population. This systematic review and meta-analysis demonstrated that the LTRs was associated with a significant increase in the incidence of renal cancer. Such association suggests that yearly routine post-transplant surveillance is need for renal cancer in LTRs.

Evaluation of combination gene therapy with PTEN and antisense hTERT for malignant glioma in vitro and xenografts.

Telomerase activation is a critical event in cell immortalization, and an increase in human telomerase reverse transcriptase (hTERT) expression is the key step in activating telomerase. The phosphatase and tensin homolog (PTEN) gene encodes a double-specific phosphatase that induces cell cycle arrest, inhibits cell growth, and causes apoptotic cell death. Here, we evaluated a combined PTEN and antisense hTERT gene therapy for experimental glioma in vitro and in vivo. We demonstrated that infection with antisense-hTERT and wild-type-PTEN adenoviruses significantly inhibited human U251 glioma cell proliferation in vitro and glioma growth in a xenograft mouse model. The efficacy of therapy was obviously higher in the tumor xenografts infected with both PTEN and antisense hTERT than in the gliomas infected with either agent alone at the same total viral dose. Consistent with these results, we showed that telomerase activity and hTERT protein levels were markedly reduced in the glioma cells following adenovirus infection. In contrast, the levels of PTEN protein expression were dramatically increased in these cells. Our data indicate that combination treatment with antisense hTERT and wild-type PTEN effectively suppresses the malignant growth of human glioma cells in vitro and in tumor xenografts, suggesting a promising new approach in glioma gene therapy that warrants further investigation.

Localization of NGF and TrkA at mitotic apparatus in human glioma cell line U251.

It has previously been implicated that nerve growth factor (NGF) with its high-affinity receptor tyrosine kinase A (TrkA) could play an important role in the growth modulation of human tumor cells, such as glioblastoma multiform cell lines and human breast cancer cell lines. However, the direct mitogenic effects of NGF and TrkA in these tumor cells still remain to be elucidated. Herein we show, by immunofluorescence staining, that NGF was colocalized with gamma-tubulin at the centrosomes or the spindle poles throughout the cell cycle and phosphorylated TrkA was colocalized with alpha-tubulin at mitotic spindle in the glioma cell line U251. The results suggest that NGF concentrated to centrosome can recruit its receptor TrkA there and cause phosphorylation of the latter. The phosphorylated TrkA with the tyrosine kinase activity may phosphorylate the tubulin and promote the mitotic spindle assembly. By these mechanisms, NGF can modulate the mitosis of human glioma cells.