Delayed Postoperative Intracerebral Hemorrhage Associated With Oral Multikinase Inhibitor Therapy for Cancer: A Case Report

Regorafenib is a multikinase inhibitor with anti-vascular endothelial growth factor receptor (VEGF) activity used as an antiangiogenic agent for metastatic colorectal cancer treatment and has been studied as a potential therapeutic agent for several other cancer treatments. Adverse reactions commonly reported with the use of regorafenib and similar oral multikinase inhibitors include hemorrhage, gastrointestinal fistulas, hypertension, and incomplete wound healing. We report a case of a 59-year-old man with metastatic colorectal adenocarcinoma post-colostomy on regorafenib treatment presenting to the emergency department with altered mental status. MRI showed a left frontoparietal mass, which was resected with a left frontal craniotomy. Postoperative MRI showed a resection cavity without significant hemorrhage. He had been prescribed regorafenib preceding his hospitalization, which was continued after admission before surgery and on postoperative day 1. Thirty-two hours after surgery, the patient exhibited sudden right-sided facial droop and right arm weakness. Imaging revealed an acute intraparenchymal hemorrhage within and adjacent to the tumor resection bed, which was managed conservatively. The patient was subsequently discharged to an inpatient rehabilitation facility. The unusual timing of the hemorrhage suggests that the hemorrhage was due to adverse effects of regorafenib. Patients undergoing neurosurgery should have regorafenib discontinued in preparation for surgery. Similar management should be considered for other anti-VEGF medications to avoid serious complications.

Superficial siderosis: comparison of two cases indicates two distinct diagnostic entities. Illustrative cases

BACKGROUND

Superficial siderosis is the deposition of hemosiderin in the superficial layers of the central nervous system. It has been described in patients with chronic leakage of blood into the cerebrospinal fluid or with amyloid angiopathy, often associated with Alzheimer's disease (AD).

OBSERVATIONS

We present two cases of superficial siderosis with vastly different symptomatologies and treatment courses. The patient in case 1 had diffuse superficial siderosis demonstrated on T2-weighted magnetic resonance imaging (MRI), appearing mostly in the inferior cerebellum and extending throughout the neuraxis. He presented with hearing loss, spasticity, gait abnormalities, and urinary incontinence. Ultimately, surgical exploration of the thoracic spinal dura revealed an arteriovenous fistula, which was obliterated. His clinical course stabilized but with persistent deficits. The patient in case 2 had a family history of AD and underwent MRI to evaluate for memory impairment, which demonstrated superficial siderosis of the left occipital lobe. Lumbar puncture demonstrated only traumatic contamination by red blood cells, but tau protein analysis was consistent with the diagnosis of AD.

LESSONS

Superficial siderosis is a diagnostic term prompted by findings on MRI that can arise due to two different pathological entities. The diagnosis in case 1 should be termed diffuse superficial siderosis and in case 2 should be termed lobar cortical siderosis.

Reducing Gadolinium Exposure in Patients Undergoing Monitoring for Meningiomas

Background Due to the non-malignant and slow-growing nature of many meningiomas, surveillance with serial magnetic resonance imaging (MRI) serves as an acceptable management plan. However, repeated imaging with gold-standard contrast-based studies may lead to contrast-associated adverse effects. Non-gadolinium T2 sequences may serve as a suitable alternative without the risk of adverse effects of contrast. Thus, this study sought to investigate the agreement between post-contrast T1 and non-gadolinium T2 MRI sequences in the measurement of meningioma growth. Methodology The Virginia Commonwealth University School of Medicine (VCU SOM) brain tumor database was used to create a cohort of meningioma patients and determine the number of patients who had T1 post-contrast imaging accompanied by readily measurable imaging from either T2 fast spin echo (FSE) or T2 fluid-attenuated inversion recovery (FLAIR) sequences. Measurements of the largest axial and perpendicular diameters of each tumor were conducted by two independent observers using T1 post-contrast, T2 FSE, and T2 FLAIR imaging series. Lin's concordance correlation coefficient (CCC) was calculated to assess inter-rater reliability between observers and agreement between measurements of tumor diameter among the different imaging sequences. Results In total, 33 patients (average age = 72.1 ± 12.9 years, 90% female) with meningiomas were extracted from our database, with 22 (66.7%) undergoing T1 post-contrast imaging accompanied with readily measurable imaging from T2 FSE and/or T2 FLAIR sequences. The inter-rater reliability between the measurements of T1 axial and perpendicular diameters was 0.96 (95% confidence interval (CI) = 0.92-0.98) and 0.92 (95% CI = 0.83-0.97), respectively. The inter-rater reliability between the measurements of T2 axial perpendicular diameters was 0.93 (95% = CI 0.92-0.97) and 0.89 (95% CI = 0.74-0.95), respectively. The agreements between the measurement of T1 and T2 FSE axial diameter by each observer were 0.97 (95% CI = 0.93-0.98) and 0.92 (95% CI = 0.81-0.97). The agreements between the measurements of T1 and T2 FSE perpendicular diameter measurements by each observer were 0.98 (95% CI = 0.95-0.99) and 0.88 (95% CI = 0.73-0.95). Conclusions Two-thirds of our patients had meningiomas that were readily measurable on either T2 FSE or T2 FLAIR sequences. Additionally, there was excellent inter-rater reliability between the observers in our study as well as an agreement between individual measurements of T1 post-contrast and T2 FSE tumor diameters. These findings suggest that T2 FSE may serve as a safe and similarly effective surveillance method for the long-term management of meningioma patients.

Growth Analysis of Untreated Meningiomas under Observation

BACKGROUND

 When meningiomas are small or asymptomatic, the decision to observe rather than treat requires balancing the growth potential of the lesion with the outcome and side effects of treatment. The aim of this study is to characterize the growth patterns of untreated meningiomas to better inform the clinical decision-making process.

METHODS

 Patients with meningiomas were identified from 2005 to 2015. Those without treatment who had been followed for 1.5 years, with three magnetic resonance imaging (MRI) scans, were identified. Scans were measured with orthogonal diameters, geometric mean diameters, and volumes using the ABC/2 method. Regression modeling determined what growth pattern these parameters best approximated.

RESULTS

 Two hundred and fifteen MRI scans for 34 female (82.9%) and 7 male (17%) patients with 43 tumors were evaluated. Initial tumor volumes ranged from 0.13 to 9.98 mL. The mean and median initial volumes were 2.44 and 1.52 mL, respectively. Follow-up times ranged from 21 to 144 months, with a median of 70 months. There were 12 tumors (28%) whose growth rates were significantly greater than zero. For all tumors, use of a linear regression model allowed accurate prediction of the future size using prior data.

CONCLUSION

 Three-quarters of presumptive meningiomas managed conservatively do not grow significantly. The remainder have significant growth over time, and the behavior could be approximated with linear regression models.

Resolution and Re-ossification of Orbital Wall Langerhans Cell Histiocytosis Following Stereotactic Needle Biopsy

Introduction Langerhans cell histiocytosis (LCH) is a rare disease that encompasses a spectrum of clinical syndromes. It is characterized by the proliferation and infiltration of white blood cells into organs or organ systems. Reports of management of these lesions have included biopsy, resection, curettage, radiation and/or chemotherapy. Case Presentation A 40-year-old man presented with a history of right proptosis and retro-orbital pain and was found to have a lytic mass involving the greater wing of the sphenoid extending into the right orbit. A stereotactic needle biopsy using neuronavigation demonstrated this to be LCH. After no further treatment, the mass spontaneously resolved, with virtual normalization of the orbital MRI at 10 months following the needle biopsy. The bony defect of the temporal bone caused by the mass also re-ossified following the needle biopsy. Discussion This report highlights the potential for an isolated LCH lesion to regress after simple needle biopsy, an outcome only rarely reported previously. Thus, expectant management of such lesions following biopsy or initial debridement should be considered prior to proceeding with additional treatment.

Early mobilization versus bed rest for incidental durotomy: an institutional cohort study

OBJECTIVE

The aim of this study was to assess whether flat bed rest for > 24 hours after an incidental durotomy improves patient outcome or is a risk factor for medical and wound complications and longer hospital stay.

METHODS

Medical records of consecutive patients undergoing thoracic and lumbar decompression procedures from 2010 to 2020 were reviewed. Operative notes and progress notes were reviewed and searched to identify patients in whom incidental durotomies occurred. The need for revision surgery related to CSF leak or wound infection was recorded. The duration of bed rest, length of hospital stay, and complications (pulmonary, gastrointestinal, urinary, and wound) were recorded. The rates of complications were compared with regard to the duration of bed rest (≤ 24 hours vs > 24 hours).

RESULTS

A total of 420 incidental durotomies were identified, indicating a rate of 6.7% in the patient population. Of the 420 patients, 361 underwent primary repair of the dura; 254 patients were prescribed bed rest ≤ 24 hours, and 107 patients were prescribed bed rest > 24 hours. There was no statistically significant difference in the need for revision surgery (7.87% vs 8.41%, p = 0.86) between the two groups, but wound complications were increased in the prolonged bed rest group (8.66% vs 15.89%, p = 0.043). The average length of stay for patients with bed rest ≤ 24 hours was 4.47 ± 3.64 days versus 7.24 ± 4.23 days for patients with bed rest > 24 hours (p < 0.0001). There was a statistically significant increase in the frequency of ileus, urinary retention, urinary tract infections, pulmonary issues, and altered mental status in the group with prolonged bed rest after an incidental durotomy. The relative risk of complications in the group with bed rest ≤ 24 hours was 50% less than the group with > 24 hours of bed rest (RR 0.5, 95% CI 0.39-0.62; p < 0.0001).

CONCLUSIONS

In this retrospective study, the rate of revision surgery was not higher in patients with durotomy who underwent immediate mobilization, and medical complications were significantly decreased. Flat bed rest > 24 hours following incidental durotomy was associated with increased length of stay and increased rate of medical complications. After primary repair of an incidental durotomy, flat bed rest may not be necessary and appears to be associated with higher costs and complications.

The Richmond Acute Subdural Hematoma Score: A Validated Grading Scale to Predict Postoperative Mortality

BACKGROUND

Traumatic acute subdural hematomas (aSDHs) are common, life-threatening injuries often requiring emergency surgery.

OBJECTIVE

To develop and validate the Richmond acute subdural hematoma (RASH) score to stratify patients by risk of mortality after aSDH evacuation.

METHODS

The 2016 National Trauma Data Bank (NTDB) was queried to identify adult patients with traumatic aSDHs who underwent craniectomy or craniotomy within 4 h of arrival to an emergency department. Multivariate logistic regression modeling identified risk factors independently associated with mortality. The RASH score was developed based on a factor's strength and level of association with mortality. The model was validated using the 2017 NTDB and the area under the receiver operating characteristic curve (AUC).

RESULTS

A total of 2516 cases met study criteria. The patients were 69.3% male with a mean age of 55.7 yr and overall mortality rate of 36.4%. Factors associated with mortality included age between 61 and 79 yr (odds ratio [OR] = 2.3, P < .001), age ≥80 yr (OR = 6.3, P < .001), loss of consciousness (OR = 2.3, P < .001), Glasgow Coma Scale score of ≤8 (OR = 2.6, P < .001), unilateral (OR = 2.8, P < .001) or bilateral (OR = 3.9, P < .001) unresponsive pupils, and midline shift >5 mm (OR = 1.7, P < .001). Using these risk factors, the RASH score predicted progressively increasing mortality ranging from 0% to 94% for scores of 0 to 8, respectively (AUC = 0.72). Application of the RASH score to 3091 cases from 2017 resulted in similar accuracy (AUC = 0.74).

CONCLUSION

The RASH score is a simple and validated grading scale that uses easily accessible preoperative factors to predict estimated mortality rates in patients with traumatic aSDHs who undergo surgical evacuation.

Positional aphasia as a manifestation of syndrome of the trephined: illustrative case

BACKGROUND

The authors report a case of a 66-year-old male who presented acutely with a subdural hematoma who was managed operatively with craniotomy. His course was complicated by a postoperative epidural hematoma, which, on the basis of intraoperative findings at the second surgery, was managed with evacuation of the hematoma and removal of the bone flap.

OBSERVATIONS

The patient’s subsequent recovery was remarkable for a reproducible positional aphasia in the early postoperative period with an ultimate diagnosis of syndrome of the trephined. The patient’s cerebral edema permitted early autologous cranioplasty, which resulted in resolution of the patient’s symptoms.

LESSONS

The authors believe this case to be the first described of isolated positional aphasia as a manifestation of syndrome of the trephined. Recognition and treatment of the syndrome resulted in a positive patient outcome.

Connexin43 Expression and Associated Chronic Inflammation Presages the Development of Cerebral Radiation Necrosis

Cerebral radiation necrosis (CRN) is a delayed complication of radiosurgery that can result in severe neurological deficits. The biological changes leading to necrotic damage may identify therapeutic targets for this complication. Connexin43 expression associated with chronic inflammation may presage the development of CRN. A mouse model of delayed CRN was used. The left hemispheres of adult female mice were irradiated with single-fraction, high-dose radiation using a Leksell Gamma Knife. The brains were collected 1 and 4 days, and 1-3 weeks after the radiation. The expression of connexin43, interleukin-1β (IL-1β), GFAP, isolectin B-4, and fibrinogen was evaluated using immunohistochemical staining and image analysis. Compared with the baseline, the area of connexin43 and IL-1β staining was increased in ipsilateral hemispheres 4 days after radiation. Over the following 3 weeks, the density of connexin43 gradually increased in parallel with progressive increases in GFAP, isolectin B-4, and fibrinogen labeling. The overexpression of connexin43 in parallel with IL-1β spread into the affected brain regions first. Further intensified upregulation of connexin43 was associated with escalated astrocytosis, microgliosis, and blood-brain barrier breach. Connexin43-mediated inflammation may underlie radiation necrosis and further investigation of connexin43 hemichannel blockage is merited for the treatment of CRN.

Comparison of ABC/2 estimation and a volumetric computerized method for measurement of meningiomas using magnetic resonance imaging

INTRODUCTION

Measurement of tumor growth rates over time for patients with meningiomas has important prognostic and therapeutic implications. Our objective was to compare two methods of measuring meningioma volume: (1) the simplified ellipsoid (ABC/2) method; and (2) perimetric volume measurements using imaging software modules.

METHODS

Patients with conservatively managed meningiomas for at least 1.5 years were retrospectively identified from the VCU Brain and Spine Tumor Registry over a 10-year period (2005-2015). Tumor volumes were independently measured using the simplified ellipsoid and computerized perimetric methods. Intra class correlations (CC) and Bland-Altman analyses were performed.

RESULTS

A total of 26 patients representing 29 tumors were identified. Across 146 images, there were 24 (16%) images that were non-measurable using standard application commands with the computerized perimetric method. The mean volume obtained using the ABC/2 and computerized perimetric methods were 3.2 ± 3.4 cm³ and 3.4 ± 3.5 cm³, respectively. The mean volume difference was 0.2 cm³ (SE = 0.12; p = 0.10) across measurement methods. The concordance correlation coefficient (CCC) between methods was 0.95 (95% CI 0.91, 0.98).

CONCLUSIONS

There is excellent correlation between the simplified ellipsoid and computerized perimetric methods of volumetric analysis for conservatively managed meningiomas. The simplified ellipsoid method remains an excellent method for meningioma volume assessment and had an advantage over the perimetric method which failed to allow measurement of roughly one in six tumors on imaging.

Outcomes after craniotomy for resection of craniopharyngiomas in adults: analysis of the National Surgical Quality Improvement Program (NSQIP)

PURPOSE

Craniopharyngiomas occur in suprasellar locations that pose challenges for surgical management. This study evaluates the incidence of complications following craniotomy for craniopharyngioma in adults and investigates risk factors for these complications.

METHODS

Patients who underwent craniotomy for excision of craniopharyngioma were identified from the 2005-2016 American College of Surgeons National Surgical Quality Improvement Program (ACS-NSQIP). Incidence of 30-day postoperative complications was determined. Multivariable logistic regression identified demographic, comorbid and perioperative characteristics associated with any complication and major (Clavien IV) complications.  RESULTS: There were 143 cases identified. Fifty-one (35.7%) had a complication, twenty (14.0%) experienced a major complication and there were four (2.8%) deaths. The most common complications were: unplanned readmission (13.3%), prolonged ventilation > 48 h (9.8%), and unplanned reoperation (9.3%). In multivariable analysis, variables significantly associated with any complication were: black race (OR 0.16; 95% CI 0.03-0.84; p = 0.03), hypertension (OR 5.04; 95% CI 1.79-14.17; p = 0.002) and longer duration of surgery (OR 1.27; 95% CI 1.01-1.58; p = 0.04). Hypertension (OR 9.33; 95% CI 1.61-54.21; p = 0.01) and longer duration of surgery (OR 1.51; 95% CI 1.05-2.17; p = 0.03) were also significant predictors for major complications.

CONCLUSION

One-third of patients undergoing craniotomy for craniopharyngioma resection experienced a postoperative complication. While high, this contrasts previously reported rates of two-thirds. Prolonged operative time and hypertension are positive predictors of major complications. This information can assist in counseling patients and decision-making for management. We note that other treatment approaches, such as endoscopic surgical techniques, radiosurgery and radiation therapy likely have different profiles and predictors of complications.

Safety Outcomes Following Spine and Cranial Neurosurgery: Evidence From the National Surgical Quality Improvement Program

BACKGROUND

The American College of Surgeons National Surgical Quality Improvement Program (ACS-NSQIP) was used to establish predictors for 30-day postoperative complications following spine and cranial neurosurgery.

MATERIALS AND METHODS

The ACS-NSQIP participant use files were queried for neurosurgical cases between 2005 and 2015. Prevalence of postoperative complications following neurosurgery was determined. Nested multivariable logistic regression analysis was used to identify demographic, comorbidity, and perioperative characteristics associated with any complication and mortality for spine and cranial surgery.

RESULTS

There were 175,313 neurosurgical cases (137,029 spine, 38,284 cranial) identified. A total of 23,723 (13.5%) patients developed a complication and 2588 (1.5%) patients died. Compared with spine surgery, cranial surgery had higher likelihood of any complication (22.2% vs. 11.1%; P<0.001) and mortality (4.8% vs. 0.5%; P<0.001). In multivariable analysis, cranial surgery had 2.73 times higher likelihood for mortality compared with spine surgery (95% confidence interval, 2.46-3.03; P<0.001), but demonstrated lower odds of any complication (odds ratio, 0.93; 95% confidence interval, 0.90-0.97; P<0.001). There were 6 predictors (race, tobacco use, dyspnea, chronic obstructive pulmonary disease, chronic heart failure, and wound classification) significantly associated with any complication, but not mortality. Paradoxically, tobacco use had an unexplained protective effect on at least one complication or any complication. Similarly, increasing body mass index was protective for any complication and mortality, which suggests there may be a newly observed "obesity paradox" in neurosurgery.

CONCLUSIONS

After controlling for demographic characteristics, preoperative comorbidities, and perioperative factors, cranial surgery had higher risk for mortality compared with spine surgery despite lower risk for other complications. These findings highlight a discrepancy in the risk for postoperative complications following neurosurgical procedures that requires emphasis within quality improvement initiatives.

Large-Volume Infusions into the Brain: A Comparative Study of Catheter Designs

BACKGROUND/AIMS

"Whole-brain" infusions have emerged as a potential need with the promise of disease-modifying therapies for neurodegenerative diseases. In addition, several current clinical trials in brain cancer utilize direct delivery of drugs that are required to fill large volumes. Such requirements may not be well served by conventional single port catheters with their "point source" of delivery. Our aim is to examine infusions into large volumes of heterogeneous tissue, aiming for uniformity of distribution.

METHODS

A porous catheter (porous brain infusion catheter, PBIC), designed by Twin Star TDS LLC, for brain infusions was developed for this study and compared with another convection-enhanced delivery catheter (SmartFlowTM NGS-NC-03 from MRI Interventions, a step end-port catheter, SEPC) in current use in clinical trials. The studies were in vivo in porcine brain. A total of 8 pigs were used: the size of the pig brain limited the porous length to 15 mm. The placements of the tips of the two catheters were chosen to be the same (at the respective brain hemispheres).

RESULTS

The PBIC and SEPC both performed comparably and well, with the PBIC having some advantage in effecting larger distributions: p ∼ 0.045, with 5 infusions from each.

CONCLUSIONS

Given the performance of the PBIC, it would be highly appropriate to use the device for therapeutic infusions in human clinical trials to assess its capability for large-volume infusions.

A systematic review of perioperative seizure prophylaxis during brain tumor resection: the case for a multicenter randomized clinical trial

OBJECTIVE

The majority of neurosurgeons administer antiepileptic drugs (AEDs) prophylactically for supratentorial tumor resection without clear evidence to support this practice. The putative benefit of perioperative seizure prophylaxis must be weighed against the risks of adverse effects and drug interactions in patients without a history of seizures. Consequently, the authors conducted a systematic review of prospective randomized controlled trials (RCTs) that have evaluated the efficacy of perioperative seizure prophylaxis among patients without a history of seizures.

METHODS

Five databases (PubMed/MEDLINE, Cochrane Central Register of Controlled Trials, CINAHL/Academic Search Complete, Web of Science, and ScienceDirect) were searched for RCTs published before May 2017 and investigating perioperative seizure prophylaxis in brain tumor resection. Of the 496 unique research articles identified, 4 were selected for inclusion in this review.

RESULTS

This systematic review revealed a weighted average seizure rate of 10.65% for the control groups. There was no significant difference in seizure rates among the groups that received seizure prophylaxis and those that did not. Further, this expected incidence of new-onset postoperative seizures would require a total of 1258 patients to enroll in a RCT, as determined by a Farrington-Manning noninferiority test performed at the 0.05 level using a noninferiority difference of 5%.

CONCLUSIONS

According to a systematic review of major RCTs, the administration of prophylactic AEDs after brain tumor resection shows no significant reduction in the incidence of seizures compared with that in controls. A large multicenter randomized clinical trial would be required to assess whether perioperative seizure prophylaxis provides benefit for patients undergoing brain tumor resection.

Perfluorocarbon emulsions radiosensitise brain tumors in carbogen breathing mice with orthotopic GL261 gliomas

Background

Tumour hypoxia limits the effectiveness of radiation therapy. Delivering normobaric or hyperbaric oxygen therapy elevates pO₂ in both tumour and normal brain tissue. However, pO2 levels return to baseline within 15 minutes of stopping therapy.

Aim

To investigate the effect of perfluorocarbon (PFC) emulsions on hypoxia in subcutaneous and intracranial mouse gliomas and their radiosensitising effect in orthotopic gliomas in mice breathing carbogen (95%O₂ and 5%CO₂).

Results

PFC emulsions completely abrogated hypoxia in both subcutaneous and intracranial GL261 models and conferred a significant survival advantage orthotopically (Mantel Cox: p = 0.048) in carbogen breathing mice injected intravenously (IV) with PFC emulsions before radiation versus mice receiving radiation alone. Carbogen alone decreased hypoxia levels substantially and conferred a smaller but not statistically significant survival advantage over and above radiation alone.

Conclusion

IV injections of PFC emulsions followed by 1h carbogen breathing, radiosensitises GL261 intracranial tumors.

Translabyrinthine vestibular schwannoma resection with simultaneous cochlear implantation

OBJECTIVES

(1) Report a rare case of translabyrinthine resection of a sporadic vestibular schwannoma (VS) and concurrent cochlear implantation (CI). (2) Discuss pre-, intra-, and post-operative considerations in this unique patient population. (3) Describe surgical and audiologic outcomes reported in this population.

METHODS

Case report and review of the literature. PubMed search 'Cochlear Implantation'[Mesh] AND ('Neuroma, Acoustic'[Mesh] OR 'VESTIBULAR SCHWANNOMA'[All Fields] OR 'SCHWANNOMA'[All Fields]) limited to humans and English language. Returned 64 search results, abstracts and references of relevant papers reviewed.

RESULTS

A 75-year-old male with longstanding history of slowly progressive severe hearing loss and tinnitus presented for evaluation of worsening imbalance, vertigo, and nausea. Workup revealed a 7 mm right intracanalicular mass on MRI concerning for vestibular schwannoma. Audiogram showed bilateral, symmetric, severe-to-profound sensorineural hearing loss, with poor open-set speech comprehension while bilaterally aided. He underwent successful concurrent right translabyrinthine resection of his VS with complete preservation of the cochlear nerve and uncomplicated cochlear implantation.

DISCUSSION

Literature review revealed few previous reports of simultaneous VS and CI. The vast majority of these were in patients with neurofibromatosis Type 2 in whom auditory outcomes were poor. This patient represents one of the few cases of concurrent translabyrinthine tumor removal and CI for a spontaneous VS.

CONCLUSION

Single-stage cochlear implantation and translabyrinthine tumor resection is a feasible and safe option to consider for auditory rehabilitation in rare situations.

Accuracy of the ABC/2 Score for Intracerebral Hemorrhage: Systematic Review and Analysis of MISTIE, CLEAR-IVH, and CLEAR III

BACKGROUND AND PURPOSE

The ABC/2 score estimates intracerebral hemorrhage (ICH) volume, yet validations have been limited by small samples and inappropriate outcome measures. We determined accuracy of the ABC/2 score calculated at a specialized reading center (RC-ABC) or local site (site-ABC) versus the reference-standard computed tomography-based planimetry (CTP).

METHODS

In Minimally Invasive Surgery Plus Recombinant Tissue-Type Plasminogen Activator for Intracerebral Hemorrhage Evacuation-II (MISTIE-II), Clot Lysis Evaluation of Accelerated Resolution of Intraventricular Hemorrhage (CLEAR-IVH) and CLEAR-III trials. ICH volume was prospectively calculated by CTP, RC-ABC, and site-ABC. Agreement between CTP and ABC/2 was defined as an absolute difference up to 5 mL and relative difference within 20%. Determinants of ABC/2 accuracy were assessed by logistic regression.

RESULTS

In 4369 scans from 507 patients, CTP was more strongly correlated with RC-ABC (r(2)=0.93) than with site-ABC (r(2)=0.87). Although RC-ABC overestimated CTP-based volume on average (RC-ABC, 15.2 cm(3); CTP, 12.7 cm3), agreement was reasonable when categorized into mild, moderate, and severe ICH (κ=0.75; P<0.001). This was consistent with overestimation of ICH volume in 6 of 8 previous studies. Agreement with CTP was greater for RC-ABC (84% within 5 mL; 48% of scans within 20%) than for site-ABC (81% within 5 mL; 41% within 20%). RC-ABC had moderate accuracy for detecting ≥5 mL change in CTP volume between consecutive scans (sensitivity, 0.76; specificity, 0.86) and was more accurate with smaller ICH, thalamic hemorrhage, and homogeneous clots.

CONCLUSIONS

ABC/2 scores at local or central sites are sufficiently accurate to categorize ICH volume and assess eligibility for the CLEAR-III and MISTIE III studies and moderately accurate for change in ICH volume. However, accuracy decreases with large, irregular, or lobar clots.

CLINICAL TRIAL REGISTRATION

URL: http://www.clinicaltrials.gov. Unique identifier: MISTIE-II NCT00224770; CLEAR-III NCT00784134.

Wilms tumor 1 gene, CD97, and the emerging biogenetic profile of glioblastoma

Glioblastoma multiforme (GBM) is the most common type of primary brain tumor, and current treatment regimens are only marginally effective. One of the most vexing and malignant aspects of GBM is its pervasive infiltration into surrounding brain tissue. This review describes the role of the Wilms tumor 1 gene (WT1) and its relationship to GBM. WT1 has several alternative splicing products, one of which, the KTS(+) variant, has been demonstrated to be involved in the transcriptional activation of a variety of oncogenes as well as the inhibition of tumor suppressor genes. Further, this paper will examine the relationship of WT1 with CD97, a gene that codes for an epidermal growth factor receptor family member, an adhesion G-protein-coupled receptor, thought to promote tumor invasiveness and migration. The authors suggest that further research into WT1 and CD97 will allow clinicians to begin to deal more effectively with the infiltrative behavior displayed by GBM and design new therapies that target this deadly disease.

Extracorporeal irradiation of tumorous calvaria: a case series

OBJECT

When intracranial tumors invade the overlying skull, gross resection typically includes removal of the involved bone. Methods used to repair the resulting structural defect in the cranium include artificial prostheses, allogeneic bone grafts, and autoclaving the autologous graft. The authors have previously reported a case involving high-dose extracorporeal ionizing radiation to treat the tumorous calvaria intraoperatively, followed by reimplantation of the treated bone flap. In this paper the authors report the long-term follow-up of that case, as well as results of using extracorporeal irradiation of tumorous calvaria (EITC) for an additional 20 patients treated similarly.

METHODS

The decision to undergo EITC was typically anticipated preoperatively, but determined intraoperatively, if upon inspection the bone flap was invaded by tumor. The bone flap was then delivered to the radiation oncology department, where a total dose of 120 Gy was delivered, using a clinical linear accelerator, over a period of approximately 15 minutes. After the intracranial tumor resection was completed, the irradiated craniotomy bone flap was reimplanted and the wound was closed in a standard fashion. A retrospective review of patients who had undergone EITC was performed for evidence of calvarial tumor recurrence or other complications.

RESULTS

Since the originally reported case, 20 additional patients have received EITC during craniotomy for invasive tumors. Eighteen (86%) of 21 patients were diagnosed with meningioma: 12 (67%) with WHO Grade I, 5 (28%) with WHO Grade II, and 1 with WHO Grade III (6%). The remaining 3 patients presented with dural-based B-cell lymphoma with extensive adjacent bone invasion (n = 2) and metastatic adenocarcinoma of the lung (n = 1). Follow-up of the 21 patients ranged from 1 to 132 months, with a mean of 41 months and a median of 23 months. No patients have experienced tumor recurrence, infection associated with the treated calvaria, or evidence of bone flap resorption.

CONCLUSIONS

Calvaria reconstructions represent an important component in structural and cosmetic outcome following craniectomy for tumorous bone. The authors' long-term experience with EITC has been excellent with no local tumor recurrence or complications. Therefore, EITC represents an excellent and efficient option for cranial reconstruction in such patients.

Depressive symptoms and cytokine levels in Serum and Tumor Tissue in patients with an Astrocytoma: a pilot study

Background

Preoperative depressive symptoms are associated with poor outcomes in patients with an astrocytoma. Cytokines are associated with depressive symptoms in the general population and are important mediators of tumor growth and progression.

The aims of this study were to: (1) characterize depressive symptoms, other treatment-related symptoms and biological mediators; and (2) determine whether preoperative depressive symptoms were associated with the selected biological mediators.

Methods

A prospective, exploratory study was carried out among 22 patients with a high-grade astrocytoma. Self-report questionnaires and peripheral blood samples were collected on the day of surgery. Tumor tissue was collected intraoperatively. Self-report questionnaires were assessed at 3, 6, 9, and 12-months postoperatively.

Results

In circulation, serum IL-8 was inversely correlated with depressive symptoms while IL-17 measured in tumor tissue supernatant was inversely correlated with depressive symptoms. Depressive symptoms showed a significant increase at 12 months from baseline levels and were positively associated with treatment-related symptoms at 3 months and symptom distress at 12 months post-surgery.

Conclusions

In this pilot study, depressive symptoms were negatively associated with IL-8 in serum and IL-17 in tumor tissue. The changes among depressive symptoms, treatment-related symptoms and symptom distress highlight the need for multi-faceted symptom management strategies over the treatment trajectory in this patient population.

The Influence of Hypoxia and pH on Bioluminescence Imaging of Luciferase-Transfected Tumor Cells and Xenografts

Bioluminescence imaging (BLI) is a relatively new noninvasive technology used for quantitative assessment of tumor growth and therapeutic effect in living animal models. BLI involves the generation of light by luciferase-expressing cells following administration of the substrate luciferin in the presence of oxygen and ATP. In the present study, the effects of hypoxia, hypoperfusion, and pH on BLI signal (BLS) intensity were evaluated in vitro using cultured cells and in vivo using a xenograft model in nude mice. The intensity of the BLS was significantly reduced in the presence of acute and chronic hypoxia. Changes in cell density, viability, and pH also affected BLS. Although BLI is a convenient non-invasive tool for tumor assessment, these factors should be considered when interpreting BLS intensity, especially in solid tumors that could be hypoxic due to rapid growth, inadequate blood supply, and/or treatment.

Metallofullerene-nanoplatform-delivered interstitial brachytherapy improved survival in a murine model of glioblastoma multiforme

Fullerenes are used across scientific disciplines because of their diverse properties gained by altering encapsulated or surface-bound components. In this study, the recently developed theranostic agent based on a radiolabeled functionalized metallofullerene ((177)Lu-DOTA-f-Gd(3)N@C(80)) was synthesized with high radiochemical yield and purity. The efficacy of this agent was demonstrated in two orthotopic xenograft brain tumor models of glioblastoma multiforme (GBM). A dose-dependent improvement in survival was also shown. The in vivo stability of the agent was verified through dual label measurements of biological elimination from the tumor. Overall, these results provide evidence that nanomaterial platforms can be used to deliver effective interstitial brachytherapy.

Novel report of expression and function of CD97 in malignant gliomas: correlation with Wilms tumor 1 expression and glioma cell invasiveness

OBJECT

The Wilms tumor 1 (WT1) protein-a developmentally regulated transcription factor-is aberrantly expressed in gliomas and promotes their malignant phenotype. However, little is known about the molecular allies that help it mediate its oncogenic functions in glioma cells.

METHODS

The authors used short interfering RNA (siRNA) to suppress WT1 expression in glioblastoma (GBM) cells and evaluated the effect of this on GBM cell invasiveness. Gene expression analysis was then used to identify the candidate genes that were altered as a result of WT1 silencing. One candidate target, CD97, was then selected for further investigation into its role by suppressing its expression using siRNA silencing, followed by proliferation and invasion assays.

RESULTS

WT1 levels were reliably and reproducibly suppressed by siRNA application. This resulted in a significant decrease in cellular invasiveness. Microarray analyses identified the gene products that were consistently downregulated (27) and upregulated (11) with WT1 silencing. Of these, CD97 expression was consistently suppressed across the 3 different GBM cell lines studied and was found on further investigation to significantly impact GBM cell invasiveness.

CONCLUSIONS

Although CD97 expression in gliomas has not been described previously, we conclude that the possible upregulation of CD97 mediated by WT1 promotes cellular invasiveness-one of the most characteristic and challenging aspects of glial tumor cells. Further studies are needed to clarify the nature of this regulation and its impact, as CD97 could represent a novel target for antiglioma therapies.

Conjugation of functionalized gadolinium metallofullerenes with IL-13 peptides for targeting and imaging glial tumors

Background: Glioblastoma multiforme is the most common and most lethal primary brain tumor in humans, with median survival of approximately 1 year. Owing to the ability of glioma cells to aggressively infiltrate normal brain tissue and survive exposure to current adjuvant therapies, there is a great need for specific targeted nanoplatforms capable of delivering both therapeutic and imaging agents directly to invasive tumor cells. Method: Gadolinium-containing endohedral fullerenes, highly efficient contrast agents for MRI, were functionalized and conjugated with a tumor-specific peptide and assessed for their ability to bind to glioma cells in vitro. Results: We report the successful conjugation of the carboxyl functionalized metallofullerene Gd3N@C80(OH)-26(CH2CH2COOH)-16 to IL-13 peptides and the successful targeting ability towards brain tumor cells that overexpress the IL-13 receptor (IL-13Rα2). Conclusion: These studies demonstrate that IL-13 peptide-conjugated gadolinium metallofullerenes could serve as a platform to deliver imaging and therapeutic agents to tumor cells.

Quantifying fluid infusions and tissue expansion in brain

The technique of direct infusions into brain tissue of therapeutic molecules that would otherwise not adequately cross the blood–brain barrier (BBB) continues to be used in clinical trials. As part of our research into understanding the transport of fluids and molecules in brain tissue, we performed infusions of a saline solution of the magnetic resonance (MR) marker Gadodiamide (Omniscan) into porcine brains. We use quantitative concentration measurements of contrast reagents from MR images to both measure the distribution profile of the infusate and to elucidate important determinants of fluid flow during infusions into brain parenchyma. Based on this, and from other MRI data collected during infusion, we give preliminary results for the quantification of the expansion of the volume fraction of the interstitium particularly in white matter regions of brain during infusion-induced edema. We claim this expansion, rather than an anisotropy of fluid conductivity, makes white matter tracts a preferred pathway for flow. We also comment briefly on other determinants that are currently being pursued such as the influence of the cerebrospinal fluid and perivascular spaces that may be elucidated with quantitative tracking of tracer, but which need further studies

A novel coaxial tube catheter for central nervous system infusions: performance characteristics in brain phantom gel

We tested a novel neurocatheter in a brain-tissue gel model of drug infusion via convection-enhanced delivery (CED) for the treatment of a variety of neurological diseases. CED is an alternative to systemic administration of agents by intravenous or oral routes, which are often less effective or carry risk of systemic side effects. We investigated two co-axial tube devices, with outer diameters of 1.6 mm and 2.0 mm. Bromophenol blue dye was infused into 400 ml of 0.6% agarose gel at 1 μl/min for 1 h, with/without the inner and outer tubes Luer-locked at the proximal end, with/without the inner tube primed, and with/without the inner tube preloaded into the outer tube upon insertion into the gel. The unlocked, primed, and unloaded configuration produced infusions that resulted in significantly less (p < 0.05) entrapped air escaping into the gel and resulted in no reflux of infusate.

A biobehavioral perspective on depressive symptoms in patients with cerebral astrocytoma

More than 51,000 individuals are diagnosed with a primary brain tumor in the United States each year, and for those with the most common type of malignant tumor, an astrocytoma, almost 75% will die within 5 years of diagnosis. Although surgery, radiation, and chemotherapy have improved length of survival, mortality remains high, which underscores the need to understand how other factors affect the disease trajectory. Several recent studies have shown that depressive symptoms are independently associated with reduced quality of life and survival time after controlling for other variables in patients with an astrocytoma. Thus, depressive symptoms represent a significant risk factor for adverse outcomes in this patient population. A growing body of evidence indicates that depressive symptoms are linked to underlying biological phenomena, particularly inflammatory activation modulated through increased peripheral levels of proinflammatory cytokines. Recent research has shown that neoplastic astrocytes respond to elevated proinflammatory cytokine levels by secreting immune mediators within the central nervous system, including cytokines and glial fibrillary acidic protein that promote astrogliosis and angiogenesis and may increase tumor growth and metastasis. However, because these biological factors have not as yet been measured in conjunction with depressive symptoms in these patients, little is known about the interactions that potentially influence the treatment trajectory. To guide future research and to provide a deeper understanding of the factors that may influence depressive symptoms and length of survival in patients with an astrocytoma, a review of the literature was undertaken. Publications over the past 10 years were analyzed to examine the theoretical models and measures of depressive symptoms used in previous research. Although numerous studies have documented the relationship between depression and reduced length of survival, there were several methodological concerns identified, and there were no studies that included biological variables. Yet, research in the basic sciences provides compelling evidence of specific neuroendocrine-immune interactions orchestrated by astrocytes that can cause depressive symptoms and alter the tumor microenvironment so that standard treatments are not as effective. These findings support the need for clinically based research so that we can begin to understand the potentially modifiable biobehavioral mechanisms underlying depressive symptoms in patients with an astrocytoma. Grounded in the biobehavioral research paradigm of psychoneuroimmunology, a novel research program is presented that may provide a new level of understanding regarding the high prevalence of depressive symptoms in patients with an astrocytoma and lead to new treatment strategies, with possible implications for improved symptom management and quality of life in patients with brain tumors.

The development of MDA-7/IL-24 as a cancer therapeutic

The cytokine melanoma differentiation associated gene 7 (mda-7) was identified by subtractive hybridization as a protein whose expression increased during the induction of terminal differentiation, and that was either not expressed or was present at low levels in tumor cells compared to non-transformed cells. Based on conserved structure, chromosomal location and cytokine-like properties, MDA-7, was classified as a member of the interleukin (IL)-10 gene family and designated as MDA-7/IL-24. Multiple studies have demonstrated that expression of MDA-7/IL-24 in a wide variety of tumor cell types, but not in corresponding equivalent non-transformed cells, causes their growth arrest and rapid cell death. In addition, MDA-7/IL-24 has been noted to radiosensitize tumor cells which in part is due to the generation of reactive oxygen species (ROS) and ceramide that cause endoplasmic reticulum stress and suppress protein translation. Phase I clinical trial data has shown that a recombinant adenovirus expressing MDA-7/IL-24 (Ad.mda-7 (INGN-241)) was safe and had measurable tumoricidal effects in over 40% of patients, strongly arguing that MDA-7/IL-24 could have significant therapeutic value. This review describes what is presently known about the impact of MDA-7/IL-24 on tumor cell biology and its potential therapeutic applications.

MDA-7/IL-24 as a cancer therapeutic: from bench to bedside

The novel cytokine melanoma differentiation associated gene-7 (mda-7) was identified by subtractive hybridization in the mid-1990s as a protein whose expression increased during the induction of terminal differentiation, and that was either not expressed or was present at low levels in tumor cells compared with non-transformed cells. On the basis of conserved structure, chromosomal location and cytokine-like properties, MDA-7, has now been classified as a member of the expanding interleukin (IL)-10 gene family and designated as MDA-7/IL-24. Multiple studies have shown that the expression of MDA-7/IL-24 in a wide variety of tumor cell types, but not in the corresponding equivalent non-transformed cells, causes their growth arrest and ultimately cell death. In addition, MDA-7/IL-24 has been noted to be a radiosensitizing cytokine, which is partly because of the generation of reactive oxygen species and ceramide that cause endoplasmic reticulum stress. Phase I clinical trial data has shown that a recombinant adenovirus expressing MDA-7/IL-24 [Ad.mda-7 (INGN-241)] was safe and had measurable tumoricidal effects in over 40% of patients, which strongly argues that MDA-7/IL-24 may have significant therapeutic value. This review describes what is known about the impact of MDA-7/IL-24 on tumor cell biology and its potential therapeutic applications.

Gd-DTPA T1 relaxivity in brain tissue obtained by convection-enhanced delivery, magnetic resonance imaging and emission spectroscopy

A common approach to quantify gadolinium (Gd) contrast agents involves measuring the post-contrast change in T1 rate and then using the constant T1 relaxivity R to determine the contrast agent concentration. Because this method is fast and non-invasive, it could be potentially valuable in many areas of brain research. However, to accurately measure contrast agent concentrations in the brain, the T1 relaxivity R of the specific agent must be accurately known. Furthermore, the macromolecular content and compartmentalization of the brain extracellular space (ECS) are expected to significantly alter R from values measured in aqueous solutions. In this study, the T1 relaxivity R of gadolinium-diethylene-triamine penta-acetic acid (Gd-DTPA) was measured following direct interstitial infusions of three different contrast agent concentrations to the parenchyma of rat brains. Changes in magnetic resonance (MR) T1 values were compared to brain slice concentrations determined with inductively coupled plasma atomic emission spectroscopy (ICP-AES) to determine R in 15 rats. Additionally, samples of cerebrospinal fluid, blood and urine were analyzed to evaluate possible Gd-DTPA clearance from the brain. The T1 relaxivity R of Gd-DTPA in the brain ECS was measured to be 5.35 (mM s)(-1) in a 2.4 T field. This value is considerably higher than estimations used in studies by other groups. Measurements of brain Gd-DTPA tissue concentrations using MRI and ICP-AES demonstrated a high degree of coincidence. Clearance of Gd-DTPA was minimal at the time point immediately after infusion. These results suggest that the environment of the brain does in fact significantly affect Gd T1 relaxivity, and that MRI can accurately measure contrast agent concentrations when this relaxivity is well characterized.

Abstract 3914: Wilms Tumor-1 (WT-1) and its target genes in gliomagenesis

WT-1 - a zinc-finger transcription factor - plays an important role during development, and is associated with the development of tumors of varied origins. Our laboratory has previously demonstrated the expression and importance of WT-1 in the growth of glial neoplasms. In this study, we have sought to identify its downstream targets in the specific context of gliomas.

Methods & results: Using Real Time RT-PCR and Western Blotting, we demonstrate an inverse correlation between WT-1 and one of its established targets- IGF-1R. Also, using the gene expression profiling technique, we have identified some of its other target genes in U251-MG cells. Key genes that are down-regulated with WT-1 silencing include: PDGF-D, TYMS, INPP5A, EPAS-1 and CD97, while genes that are found to be up-regulated with WT-1 silencing include: TIMP-3 and LZTS-1. These results have been validated at the RNA and/ or protein level using Real Time RT-PCR and/ or Western Blot analysis. Further, we demonstrate the effects of manipulating WT-1 levels on some of these newly identified targets, selected for their importance in different aspects of tumor biology.

Conclusion: WT-1 is clearly implicated in the development and progression of gliomas. By identifying the molecular allies that help this protein promote oncogenesis, we hope to gain important insights for the development of a multi-molecular targeting strategy against these aggressive tumors

Abbreviations: IGF-1R: Insulin-like growth factor-1 Receptor; PDGF-D: Platelet-Derived Growth Factor-D; TYMS: Thymidylate Synthetase; INPP5A- Inositol Polyphosphate-5-Phosphatase; EPAS-1: endothelial PAS domain protein 1; TIMP-3: Tissue inhibitor metallopeptidase-3; LZTS-1: leucine zipper, putative tumor suppressor 1.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 101st Annual Meeting of the American Association for Cancer Research; 2010 Apr 17-21; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2010;70(8 Suppl):Abstract nr 3914.

Effect of WT1 gene silencing on the tumorigenicity of human glioblastoma multiforme cells

OBJECT

Wilms tumor 1 (WT1) is overexpressed in many human cancers, including glioblastoma multiforme (GBM). In another study, the authors showed that transient WT1 silencing increases the radiosensitivity of glioma cells. Studies of nonglioma cell lines have demonstrated that WT1 promotes cell proliferation and survival; however, this ability has not been rigorously analyzed in human GBM.

METHODS

The authors tested the efficacy of 2 sequences of short hairpin RNA (shRNA) directed against WT1 in U251MG human GBM cells and found that 1 sequence was capable of stably silencing WT1 expression. They then evaluated the effect of WT1 silencing on cellular proliferation, invasion, and in vivo tumor formation.

RESULTS

Stable WT1-shRNA expression significantly decreased the proliferation of U251MG cells in vitro as demonstrated by both an adenosine 5'-triphosphate-based viability assay and tritiated thymidine uptake. Furthermore, stable WT1 silencing caused significantly slower growth after the subcutaneous inoculation of tumor cells in the flanks of athymic nude mice and was associated with an increased latency period.

CONCLUSIONS

Data in this study provide proof of the principle that downregulation of WT1 causes decreased tumorigenicity of a GBM cell line in vitro and in vivo and suggest that WT1 is a promising target for novel molecular GBM therapies, perhaps in combination with standard treatment modalities.

PERK-dependent regulation of ceramide synthase 6 and thioredoxin play a key role in mda-7/IL-24-induced killing of primary human glioblastoma multiforme cells

Melanoma differentiation associated gene-7(mda-7) encodes IL-24, a cytokine that can selectively trigger apoptosis in transformed cells. Recombinant mda-7 adenovirus (Ad.mda-7) effectively kills glioma cells, offering a novel gene therapy strategy to address deadly brain tumors. In this study, we defined the proximal mechanisms by which Ad-mda-7 kills glioma cells. Key factors implicated included activation of the endoplasmic reticulum stress kinase protein kinase R-like endoplasmic reticulum kinase (PERK), Ca(++) elevation, ceramide generation and reactive oxygen species (ROS) production. PERK inhibition blocked ceramide or dihydroceramide generation, which were critical for Ca(++) induction and subsequent ROS formation. Activation of autophagy and cell death relied upon ROS formation, the inhibition of which ablated Ad.mda-7-killing activity. In contrast, inhibiting TRX induced by Ad.MDA-7 enhanced tumor cytotoxicity and improved animal survival in an orthotopic tumor model. Our findings indicate that mda-7/IL-24 induces an endoplasmic reticulum stress response that triggers production of ceramide, Ca(2+), and ROS, which in turn promote glioma cell autophagy and cell death.

Primary brain T-cell lymphoma of the lymphoblastic type presenting as altered mental status

The authors present a case of a 56-year-old man with altered mental status. Magnetic resonance imaging (MRI) of the brain revealed non-enhancing abnormalities on T2 and FLAIR imaging in the brainstem, cerebellum, and cerebrum. Immunohistochemisty demonstrated precursor T-cell lymphoblastic lymphoma. After treatment with methotrexate, he improved clinically without focal sensorimotor deficits and with improving orientation. MRI showed almost complete resolution of brainstem and cerebral lesions. To the authors’ knowledge, there are only five previous reports of primary central nervous system T-cell lymphoblastic lymphoma. Since treatable, it deserves consideration in patients with altered mental status and imaging abnormalities that include diffuse, non-enhancing changes with increased signal on T2-weighted images.

The alkylphospholipid perifosine induces apoptosis and p21-mediated cell cycle arrest in medulloblastoma

Medulloblastoma is the most common malignant cancer of the central nervous system in children. AKT kinases are part of a survival pathway that has been found to be significantly elevated in medulloblastoma. This pathway is a point of convergence for many growth factors and controls cellular processes that are critical for tumor cell survival and proliferation. The alkyl-phospholipid perifosine [octadecyl-(1,1-dimethyl-4-piperidylio) phosphate] is a small molecule inhibitor in clinical trials in peripheral cancers which acts as a competitive inhibitor of AKT kinases. Medulloblastoma cell cultures were used to study the effects of perifosine response in preclinical studies in vitro. Perifosine treatment led to the rapid induction of cell death in medulloblastoma cell lines, with pronounced suppression of phosphorylated AKT in a time-dependent and concentration-dependent manner. LD(50) concentrations were established using viability assays for perifosine, cisplatin, and etoposide. LD(50) treatment of medulloblastoma cells with perifosine led to the cleavage of caspase 9, caspase 7, caspase 3, and poly-ADP ribosylation protein, although caspase 8 was not detectable. Combination single-dose treatment regimens of perifosine with sublethal doses of etoposide or irradiation showed a greater than additive effect in medulloblastoma cells. Lower perifosine concentrations induced cell cycle arrest at the G(1) and G(2) cell cycle checkpoints, accompanied by increased expression of the cell cycle inhibitor p21(cip1/waf1). Treatment with p21 small interfering RNA prevented perifosine-induced cell cycle arrest. These findings indicate that perifosine, either alone or in combination with other chemotherapeutic drugs, might be an effective therapeutic agent for the treatment of medulloblastoma.

In vitro angiogenesis by human umbilical vein endothelial cells (HUVEC) induced by three-dimensional co-culture with glioblastoma cells

Glioblastoma multiforme (GBM) is one of the most highly vascularized of all human tumors. Our objective was to characterize a 3-dimensional (3-D) in vitro angiogenesis model by co-culturing HUVEC and GBM cells, and to study the role of VEGF in mediating capillary tubule formation in this model. HUVEC-coated dextran beads were suspended in fibrin gel with human glioma cells on top. The number of sprouts and the length of the processes were measured. HUVEC can be induced to form sprouts and longer processes with lumens, in co-culture with glioma cells that secrete VEGF. Addition of exogenous VEGF enhances this effect. In the absence of glioma cells, many single HUVEC migrate away from the beads, without significant tubule formation. Hypoxia further stimulated sprout formation by 50-100%. Anti-VEGF neutralizing antibody suppressed HUVEC sprouting by 75% in co-culture with glioma cells. This 3-D in vitro co-culture system provides a robust and useful model for analysis of the major steps of glioma-induced angiogenesis.

MDA-7/IL-24 plus radiation enhance survival in animals with intracranial primary human GBM tumors

Melanoma differentiation associated gene-7/interleukin 24 (mda-7/IL-24) is a cytokine displaying selective apoptosis-inducing activity in tumors, including glioblastoma (GBM), without damaging normal cells. The present studies focused on defining whether an adenovirus expressing MDA-7/IL-24, Ad.mda-7, infused into pre-formed invasive primary human GBM tumors growing in athymic mouse brains altered tumor cell growth and animal survival, and whether Ad.mda-7 radiosensitized GBM cells and enhanced the survival benefit of irradiation. Ad.mda-7 directly radiosensitized glioma cells in vitro in a JNK1-3- and caspase 9-dependent fashion and demonstrated bystander-effect killing and radiosensitization of GBM cells when primary human astrocytes were infected with Ad.mda-7. Infusion of Ad.mda-7 into pre-formed glioma tumors caused a rapid decrease in proliferation and blood vessel density and an increase in cell killing. Irradiation of Ad.mda-7 infected tumors enhanced cell death. Cell killing correlated with pro-caspase 3 cleavage, enhanced phosphorylation of JNK1-3 and reduced phosphorylation of ERK1/2. Ad.mda-7 enhanced the survival of animals implanted with GBM6 and GBM12 tumors, and significantly increased the survival benefit of irradiation in animals bearing GBM12 tumors. Ad.mda-7 toxicity was evident against CD133+ and CD133- GBM cells; upon tumor re-growth approximately 70-100 days after virus infusion, the relative CD133+ level within the tumor was profoundly reduced with lower Ki67 reactivity and increased beta-galactosidase staining. Infusion of Ad.mda-7 into an immune competent rat brain did not cause normal tissue toxicity 1-4 weeks after infusion using T1 and T2 weighted MRI and H&E staining. Our data demonstrate that Ad.mda-7 prolongs the survival of animals bearing GBM tumors and does so through multiple mechanisms including direct tumor cell killing and selection for surviving cells that are more differentiated and potentially displaying a putatively senescent phenotype.

Wilms tumor 1 expression in malignant gliomas and correlation of +KTS isoforms with p53 status

Object

The WT1 gene is overexpressed in many types of human cancer. It has been demonstrated that Wilms tumor 1 (WT1) promotes tumor cell proliferation and survival in some cell lines by inhibiting p53-mediated apoptosis; however, this relationship has not been investigated in gliomas. The goal in this study was to characterize the expression pattern of WT1 in human gliomas and to determine if a correlation exists between WT1 expression and p53 status.

Methods

The authors screened nine malignant glioma cell lines, 50 glioblastoma multiforme (GBM) samples, and 16 lower-grade glial tumors for WT1 expression.

Results

Five of nine cell lines, 44 of 50 GBM samples, and 13 of 16 lower-grade gliomas expressed WT1 mRNA on reverse transcriptase polymerase chain reaction (PCR) analysis. Expression of WT1 was not detected in normal astrocytes. Two WT1 isoforms, +/+ and −/+, were expressed in the majority of these samples. Real-time PCR analysis of the GBM cell lines revealed that the level of WT1 mRNA ranged from 6.33 to 214.70 ng per ng 18S ribosomal RNA. The authors screened the GBM samples for p53 mutation by using PCR and single-stranded conformational polymorphism analysis, and they demonstrated an association between WT1 expression and p53 status. Tumors that contained wild-type p53 were significantly more likely to express WT1 than tumors that contained mutant p53.

Conclusions

The presence of WT1 in glioma cell lines and the majority of primary tumor samples and its absence in normal astrocytes support the suggestion that WT1 expression is important in glioma biology.

Ectopic telomerase expression inhibits neuronal differentiation of NT2 neural progenitor cells

There is significant interest in the potential use of telomerase-immortalized cells in transplantation to replace neurons lost to neurodegenerative diseases and other central nervous system injuries. Neural progenitor cells (NPCs) transduced with human telomerase reverse transcriptase (hTERT), the catalytic component of telomerase, have the potential both to proliferate indefinitely in vitro and to respond to differentiation signals necessary for generating appropriate cells for transplantation. The purpose of this study was to evaluate the differentiation of neurons from NT2 cells, a model NPC cell line, following hTERT transduction. RT-PCR and telomerase activity data demonstrated that persistent exogenous hTERT expression significantly inhibited the differentiation of neurons from NT2 cells. Following retinoic acid induced differentiation, hTERT-NT2 cells produced only one fourth of the neurons generated by parental and vector-control cells. A differentiation-inhibiting effect of constitutive telomerase activity has not been reported previously in other hTERT-transduced progenitor cell lines, implying a unique role for telomerase in the proliferation and differentiation of NPCs that have tumorigenic potential. Elucidating the mechanism responsible for this effect may aid in understanding the potential role of telomerase activity in the tumorigenicity of NPCs, as well as in optimizing the production of safe, telomerase-engineered, transplantable neurons.

Neural stem cell-preserving external-beam radiotherapy of central nervous system malignancies

PURPOSE

Recent discoveries have implicated neural stem cells (NSC) as the source of plasticity and repair in the mature mammalian brain. Treatment-induced NSC dysfunction may lead to observed toxicity. This study evaluates the feasibility of NSC-preserving external beam radiotherapy.

METHODS AND MATERIALS

A single computed tomography (CT) dataset depicting a right periventricular lesion was used in this study as this location reflects the most problematic geometric arrangement with respect to NSC preservation. Conventional and NSC preserving radiotherapy (RT) plans were generated for the same lesion using two clinical scenarios: cerebral metastatic disease and primary high-grade glioma. Disease-specific target volumes were used. Metastatic disease was conventionally treated with whole-brain radiotherapy (WBRT) to 3,750 cGy (15 fractions) followed by a single stereotactic radiosurgery (SRS) boost of 1,800 cGy to gross disease only. High-grade glioma was treated with conventional opposed lateral and anterior superior oblique beams to 4,600 cGy (23 fractions) followed by a 1,400 cGy (7 fractions) boost. NSC preservation was achieved in both scenarios with inverse-planned intensity modulated radiotherapy (IMRT).

RESULTS

Cumulative dose reductions of 65% (metastatic disease) and 25% (high-grade glioma) to the total volume of the intracranial NSC compartments were achieved with NSC-preserving IMRT plans. The reduction of entry and exit dose to NSC niches located contralateral to the target contributed most to NSC preservation.

CONCLUSIONS

Neural stem cells preservation with current external beam radiotherapy techniques is achievable in context of both metastatic brain disease and high-grade glioma, even when the target is located adjacent to a stem cell compartment. Further investigation with clinical trials is warranted to evaluate whether NSC preservation will result in reduced toxicity.

Microarray analysis of MRI-defined tissue samples in glioblastoma reveals differences in regional expression of therapeutic targets

Microarray technologies have come into prominence for the assessment of molecular diagnostic profiles in cancer tissue biopsies. To better understand the effect of sampling bias, we paired image-guided stereotactic biopsy and microarray technology to study regional intratumoral differences in tumor periphery and core regions of untreated glioblastoma. RNA was extracted from serial frozen sections using an integral histopathologic scoring approach. Gene expression analysis was performed using high-density oligonucleotide microarrays (22,283 probe sets). A consensus list of 643 genes (784 probe sets) with greater than 2-fold difference between intratumoral periphery and core samples was obtained using Microarray Suite 5.0, model-based expression indexes, and robust multiarray analysis algorithms. Results were validated using quantitative polymerase chain reaction and Western blotting analyses. Reproducible profiles emerged, in which multiple therapeutic targets significant to glioblastoma [matrix metalloproteinases, AKT1 (v-akt murine thymoma viral oncogene homolog 1), epidermal growth factor receptor, vascular endothelial growth factor] showed significant differences in regional expression that may affect treatment response. This study suggests important intratumoral regional differences in the molecular phenotype of glioblastoma.

Down-regulation of Wilms’ tumor 1 expression in glioblastoma cells increases radiosensitivity independently of p53

The Wilms' tumor 1 (WT1) gene is overexpressed in human glioblastoma and correlates with wild-type p53 status. In other cell types, WT1 inhibits p53-mediated apoptosis in response to DNA damaging agents. However, neither this interaction nor the relationship between WT1 and radiosensitivity has been studied in glioblastoma. To study this interaction, we generated LN-229 glioma cell lines (p53 mutant) stably expressing WT1 isoforms and induced apoptosis by transfecting with different doses of wild-type p53 plasmid expression vector. Constitutive expression of WT1 did not protect against exogenous p53-mediated apoptosis. Likewise, WT1 expression did not protect against endogenous p53-mediated cell death induced by radiotherapy in U87MG cells, which contain functional wild-type p53. We then tested the efficacy of WT1 siRNA in inhibiting WT1 expression and its effect on radiosensitivity. In T98G and LN-18 glioma cells, which possess p53 mutations, WT1 siRNA decreased WT1 protein to almost undetectable levels by 96-h post-transfection. Furthermore, WT1 siRNA transfection caused a significantly larger decrease in viability following irradiation than was seen in untransfected cells in both cell lines after treatment with ED50 of ionizing radiation. In conclusion, WT1 overexpression did not protect against p53-mediated apoptosis or ionizing radiation induced cell death. WT1 siRNA increased the radiosensitivity of two human glioma cell lines independently of p53. Anti-WT1 strategies may, therefore, prove useful in improving the response of glioblastoma to radiotherapy, thus potentially improving patient survival.

In vitro and in vivo imaging studies of a new endohedral metallofullerene nanoparticle

PURPOSE

To evaluate the effectiveness of a functionalized trimetallic nitride endohedral metallofullerene nanoparticle as a magnetic resonance (MR) imaging proton relaxation agent and to follow its distribution for in vitro agarose gel infusions and in vivo infusions in rat brain.

MATERIALS AND METHODS

The animal study was approved by the animal care and use committee. Gd(3)N@C(80) was functionalized with poly(ethylene glycol) units, and the carbon cage was hydroxylated to provide improved water solubility and biodistribution. Relaxation rate measurements (R1 = 1/T1 and R2 = 1/T2) of water solutions of this contrast agent were conducted at 0.35-, 2.4-, and 9.4-T MR imaging. Images of contrast agent distributions were produced following infusions in six agarose gel samples at 2.4 T and from direct brain infusions into normal and tumor-bearing rat brain at 2.4 T. The relaxivity of a control functionalized lutetium agent, Lu(3)N@C(80), was also determined.

RESULTS

Water hydrogen MR imaging relaxivity (r1) for this metallofullerene nanoparticle was markedly higher than that for commercial agents (eg, gadodiamide); r1 values of 102, 143, and 32 L . mmol(-1) . sec(-1) were measured at 0.35, 2.4, and 9.4 T, respectively. In studies of in vitro agarose gel infusion, the use of functionalized Gd(3)N@C(80) at concentrations an order of magnitude lower resulted in equivalent visualization in comparison with commercial agents. Comparable contrast enhancement was obtained with direct infusions of 0.013 mmol/L of Gd(3)N@C(80) and 0.50 mmol/L of gadodiamide in live normal rat brain. Elapsed-time studies demonstrated lower diffusion rates for Gd(3)N@C(80) relative to gadodiamide in live normal rat brain tissue. Functionalized metallofullerenes directly infused into a tumor-bearing brain provided an improved tumor delineation in comparison with the intravenously injected conventional Gd(3+) chelate. A control lutetium functionalized Lu(3)N@C(80) nanoparticle exhibited very low MR imaging relaxivity.

CONCLUSION

The new functionalized trimetallic nitride endohedral metallofullerene species Gd(3)N@C(80)[DiPEG5000(OH)(x)] is an effective proton relaxation agent, as demonstrated with in vitro relaxivity and MR imaging studies, in infusion experiments with agarose gel and in vivo rat brain studies simulating clinical conditions of direct intraparenchymal drug delivery for the treatment of brain tumors.

Isolation of neuronal progenitor cells from the adult human neocortex

BACKGROUND

The reliability of harvesting neuronal progenitor cells (NPCs) from the adult human neocortex has not been established, with respect to preparing autologous cell cultures for transplantation in stroke and traumatic brain injured patients.

METHOD

Enriched NPC cultures have been generated from nonneurogenic regions of the adult rodent brain by buoyancy-dependent fractionation, but the feasibility of using such a method to isolate NPCs from the adult human cortex has not been reported previously. To determine if a starter population of human adult cortical NPCs could be isolated for in vitro expansion using this method, tissue samples from five patients undergoing cortical resection for either epilepsy or trauma were assayed.

FINDINGS

Cultured cells generated from all patients predominately expressed both the NPC marker nestin and neuron-specific beta-tubulin III. The presence of NPCs was verified by in vitro BrdU/beta-tubulin III co-labeling and increasing beta-tubulin expression in differentiating conditions. Despite the formation of aggregates in monolayer culture, cell proliferation as measured by BrdU incorporation was not as prevalent as that reported from rodent cultures generated by this protocol.

CONCLUSIONS

NPCs isolated from the adult human neocortex using this method expressed beta-tubulin III in larger percentages than has been previously reported for NPCs isolated using other methods. As such, these data suggest the possibility of culturing dividing neuroblasts from the adult neocortex for further manipulation as transplantable cells.

Association of a single nucleotide polymorphism in the matrix metalloproteinase-1 promoter with glioblastoma

A key feature in the malignant behavior of glioblastoma is the tendency to invade host brain tissue surrounding the primary tumor site. Several members of the matrix metalloproteinase family are thought to contribute to this invasive capacity. A single nucleotide polymorphism has been described in the matrix metalloproteinase-1 (MMP-1) promoter that consists of either the presence or absence of a guanine nucleotide at position -1607. The presence of the guanine base creates a functional binding site for members of the ETS family of transcription factors and has been shown to increase MMP-1 transcription. The purpose of our study was to characterize this polymorphism in human glioblastoma. Promoter genotyping was performed on brain tumor tissue obtained from 81 patients and compared to 57 healthy individuals. The 2G/2G genotype is more prevalent in glioblastoma tissue compared to healthy individuals (p = 0.01). mRNA and protein expression were measured in a subset of brain tumor and normal brain tissue samples. MMP-1 protein levels are significantly higher in glioblastoma tissue compared to normal brain (p = 0.001). Electromobility shift assays and promoter assays were performed to assess binding capability and transcriptional activity, respectively. Proteins present in glioma cell lines can specifically bind the 2G promoter probe. MMP-1 transcription is significantly higher in cells transfected with the 2G promoter when compared to cells transfected with the 1G promoter (p<0.02). This polymorphism may provide a mechanism for increased expression of MMP-1 in malignant gliomas via elevation of MMP-1 mRNA transcription and may underlie the invasive phenotype.